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(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
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SPDX-License-Identifier: GPL-2.0-only/* * CPPC (Collaborative Processor Performance Control) methods used by CPUfreq drivers. * * (C) Copyright 2014, 2015 Linaro Ltd. * Author: Ashwin Chaugule <ashwin.chaugule@linaro.org> * * CPPC describes a few methods for controlling CPU performance using * information from a per CPU table called CPC. This table is described in * the ACPI v5.0+ specification. The table consists of a list of * registers which may be memory mapped or hardware registers and also may * include some static integer values. * * CPU performance is on an abstract continuous scale as against a discretized * P-state scale which is tied to CPU frequency only. In brief, the basic * operation involves: * * - OS makes a CPU performance request. (Can provide min and max bounds) * * - Platform (such as BMC) is free to optimize request within requested bounds * depending on power/thermal budgets etc. * * - Platform conveys its decision back to OS * * The communication between OS and platform occurs through another medium * called (PCC) Platform Communication Channel. This is a generic mailbox like * mechanism which includes doorbell semantics to indicate register updates. * See drivers/mailbox/pcc.c for details on PCC. * * Finer details about the PCC and CPPC spec are available in the ACPI v5.1 and * above specifications. */
#define pr_fmt(fmt) "ACPI CPPC: " fmt
#include <linux/delay.h>#include <linux/interval_tree_generic.h>#include <linux/iopoll.h>#include <linux/ktime.h>#include <linux/list.h>#include <linux/mutex.h>#include <linux/rbtree.h>#include <linux/rwsem.h>#include <linux/wait.h>#include <linux/topology.h>#include <linux/dmi.h>#include <linux/units.h>#include <linux/unaligned.h>
#include <acpi/cppc_acpi.h>
struct cppc_pcc_data { struct pcc_mbox_chan *pcc_channel; bool pcc_channel_acquired; unsigned int deadline_us; unsigned int pcc_mpar, pcc_mrtt, pcc_nominal;
bool pending_pcc_write_cmd; /* Any pending/batched PCC write cmds? */ bool platform_owns_pcc; /* Ownership of PCC subspace */ unsigned int pcc_write_cnt; /* Running count of PCC write commands */
/* * Lock to provide controlled access to the PCC channel. * * For performance critical usecases(currently cppc_set_perf) * We need to take read_lock and check if channel belongs to OSPM * before reading or writing to PCC subspace * We need to take write_lock before transferring the channel * ownership to the platform via a Doorbell * This allows us to batch a number of CPPC requests if they happen * to originate in about the same time * * For non-performance critical usecases(init) * Take write_lock for all purposes which gives exclusive access */ struct rw_semaphore pcc_lock; /* Serialize byte-oriented accesses to aliased PCC payload fields. */ raw_spinlock_t payload_lock;
/* Wait queue for CPUs whose requests were batched */ wait_queue_head_t pcc_write_wait_q; ktime_t last_cmd_cmpl_time; ktime_t last_mpar_reset; int mpar_count; int refcount;};
/* Array to represent the PCC channel per subspace ID */static struct cppc_pcc_data *pcc_data[MAX_PCC_SUBSPACES];static DEFINE_MUTEX(pcc_data_lock);/* The cpu_pcc_subspace_idx contains per CPU subspace ID */static DEFINE_PER_CPU(int, cpu_pcc_subspace_idx);
/* * The cpc_desc structure contains the ACPI register details * as described in the per CPU _CPC tables. The details * include the type of register (e.g. PCC, System IO, FFH etc.) * and destination addresses which lets us READ/WRITE CPU performance * information using the appropriate I/O methods. */static DEFINE_PER_CPU(struct cpc_desc *, cpc_desc_ptr);
/* Protect immutable capability queries against descriptor removal. */static DEFINE_MUTEX(cpc_desc_lock);
static void cpc_set_desc(unsigned int cpu, struct cpc_desc *desc){ guard(mutex)(&cpc_desc_lock); per_cpu(cpc_desc_ptr, cpu) = desc;}
struct cpc_sysmem_node { struct rb_node rb; u64 subtree_last; u64 start; u64 last; struct cpc_desc *desc; unsigned int reg_idx; struct list_head aliases; struct list_head alias_node; struct cpc_sysmem_node *alias_of; bool registered;};
struct cpc_non_mmio_node { struct rb_node rb; u64 subtree_last; u64 start; u64 last; struct cpc_desc *desc; unsigned int reg_idx; u8 space_id; u8 pcc_ss_id; bool registered;};
#define CPC_SYSMEM_START(node) ((node)->start)#define CPC_SYSMEM_LAST(node) ((node)->last)
INTERVAL_TREE_DEFINE(struct cpc_sysmem_node, rb, u64, subtree_last, CPC_SYSMEM_START, CPC_SYSMEM_LAST, static inline, cpc_sysmem_itree)
static struct rb_root_cached cpc_sysmem_tree = RB_ROOT_CACHED;static DEFINE_MUTEX(cpc_sysmem_lock);
#define CPC_NON_MMIO_START(node) ((node)->start)#define CPC_NON_MMIO_LAST(node) ((node)->last)
INTERVAL_TREE_DEFINE(struct cpc_non_mmio_node, rb, u64, subtree_last, CPC_NON_MMIO_START, CPC_NON_MMIO_LAST, static inline, cpc_non_mmio_itree)
static struct rb_root_cached cpc_pcc_trees[MAX_PCC_SUBSPACES];static struct rb_root_cached cpc_sysio_tree = RB_ROOT_CACHED;static DEFINE_MUTEX(cpc_non_mmio_lock);
static struct cpc_sysmem_node *cpc_sysmem_first(u64 start, u64 last){ return cpc_sysmem_itree_iter_first(&cpc_sysmem_tree, start, last);}
static struct cpc_sysmem_node *cpc_sysmem_next(struct cpc_sysmem_node *node, u64 start, u64 last){ return cpc_sysmem_itree_iter_next(node, start, last);}
#define CPC_PCC_HEADER_SIZE 0x8
/* pcc mapped address + header size + offset within PCC subspace */#define GET_PCC_VADDR(offs, pcc_ss_id) (pcc_data[pcc_ss_id]->pcc_channel->shmem + \ CPC_PCC_HEADER_SIZE + (offs))
/* Check if a CPC register is in PCC */#define CPC_IN_PCC(cpc) ((cpc)->type == ACPI_TYPE_BUFFER && \ (cpc)->cpc_entry.reg.space_id == \ ACPI_ADR_SPACE_PLATFORM_COMM)
/* Check if a CPC register is in FFH */#define CPC_IN_FFH(cpc) ((cpc)->type == ACPI_TYPE_BUFFER && \ (cpc)->cpc_entry.reg.space_id == \ ACPI_ADR_SPACE_FIXED_HARDWARE)
/* Check if a CPC register is in SystemMemory */#define CPC_IN_SYSTEM_MEMORY(cpc) ((cpc)->type == ACPI_TYPE_BUFFER && \ (cpc)->cpc_entry.reg.space_id == \ ACPI_ADR_SPACE_SYSTEM_MEMORY)
/* Check if a CPC register is in SystemIo */#define CPC_IN_SYSTEM_IO(cpc) ((cpc)->type == ACPI_TYPE_BUFFER && \ (cpc)->cpc_entry.reg.space_id == \ ACPI_ADR_SPACE_SYSTEM_IO)
/* Evaluates to True if reg is a NULL register descriptor */#define IS_NULL_REG(reg) ((reg)->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY && \ (reg)->address == 0 && \ (reg)->bit_width == 0 && \ (reg)->bit_offset == 0 && \ (reg)->access_width == 0)
/* Evaluates to True if an optional cpc field is supported */#define CPC_SUPPORTED(cpc) ((cpc)->type == ACPI_TYPE_INTEGER ? \ !!(cpc)->cpc_entry.int_value : \ !IS_NULL_REG(&(cpc)->cpc_entry.reg))
static bool cpc_is_writable(const struct cpc_register_resource *cpc){ return cpc->type == ACPI_TYPE_BUFFER && !IS_NULL_REG(&cpc->cpc_entry.reg) && !cpc->cpc_entry.write_unsupported;}
static bool cpc_is_readable(const struct cpc_register_resource *cpc){ return cpc->type != ACPI_TYPE_BUFFER || !cpc->cpc_entry.read_unsupported;}
static bool cpc_entry_present(const struct cpc_register_resource *cpc){ if (cpc->type == ACPI_TYPE_INTEGER) return true;
return cpc->type == ACPI_TYPE_BUFFER && !IS_NULL_REG(&cpc->cpc_entry.reg);}
/* * Each bit indicates the optionality of the register in per-cpu * cpc_regs[] with the corresponding index. 0 means mandatory and 1 * means optional. */#define REG_OPTIONAL (0x7FC7D0)
/* * Use the index of the register in per-cpu cpc_regs[] to check if * it's an optional one. */#define IS_OPTIONAL_CPC_REG(reg_idx) (REG_OPTIONAL & (1U << (reg_idx)))
static bool cpc_integer_entry_valid(unsigned int reg_idx, u64 value, bool *legacy_null){ *legacy_null = false;
switch (reg_idx) { case HIGHEST_PERF: case NOMINAL_PERF: case LOW_NON_LINEAR_PERF: case LOWEST_PERF: case REFERENCE_PERF: case LOWEST_FREQ: case NOMINAL_FREQ: return value <= U32_MAX; case CTR_WRAP_TIME: /* AML Integers and the kernel interface are both 64-bit. */ return true; case AUTO_SEL_ENABLE: return value <= 1; case DESIRED_PERF: /* Validated against Autonomous Selection after parsing. */ *legacy_null = value == 0; return *legacy_null; default: /* Tolerate legacy Integer 0 placeholders for absent options. */ *legacy_null = value == 0 && IS_OPTIONAL_CPC_REG(reg_idx); return *legacy_null; }}
/* * Arbitrary Retries in case the remote processor is slow to respond * to PCC commands. Keeping it high enough to cover emulators where * the processors run painfully slow. */#define NUM_RETRIES 500ULL
#define CPC_GENERIC_REGISTER_DESCRIPTOR 0x82#define CPC_GENERIC_REGISTER_LENGTH (sizeof(struct cpc_reg) - 3)
#define define_one_cppc_ro(_name) \static struct kobj_attribute _name = \__ATTR(_name, 0444, show_##_name, NULL)
#define to_cpc_desc(a) container_of(a, struct cpc_desc, kobj)
#define show_cppc_data(access_fn, struct_name, member_name) \ static ssize_t show_##member_name(struct kobject *kobj, \ struct kobj_attribute *attr, char *buf) \ { \ struct cpc_desc *cpc_ptr = to_cpc_desc(kobj); \ struct struct_name st_name = {0}; \ int ret; \ \ ret = access_fn(cpc_ptr->cpu_id, &st_name); \ if (ret) \ return ret; \ \ return sysfs_emit(buf, "%llu\n", \ (u64)st_name.member_name); \ } \ define_one_cppc_ro(member_name)
show_cppc_data(cppc_get_perf_caps, cppc_perf_caps, highest_perf);show_cppc_data(cppc_get_perf_caps, cppc_perf_caps, lowest_perf);show_cppc_data(cppc_get_perf_caps, cppc_perf_caps, nominal_perf);show_cppc_data(cppc_get_perf_caps, cppc_perf_caps, reference_perf);show_cppc_data(cppc_get_perf_caps, cppc_perf_caps, lowest_nonlinear_perf);show_cppc_data(cppc_get_perf_caps, cppc_perf_caps, guaranteed_perf);show_cppc_data(cppc_get_perf_caps, cppc_perf_caps, lowest_freq);show_cppc_data(cppc_get_perf_caps, cppc_perf_caps, nominal_freq);
show_cppc_data(cppc_get_perf_ctrs, cppc_perf_fb_ctrs, wraparound_time);
/* * PCC reuses the access_width field as the subspace id, so only decode access * size for non-PCC registers. Otherwise, use the bit_width. */#define GET_BIT_WIDTH(reg) (((reg)->access_width && \ (reg)->space_id != ACPI_ADR_SPACE_PLATFORM_COMM) ? \ (8 << ((reg)->access_width - 1)) : (reg)->bit_width)
/* Shift and apply the mask for CPC reads/writes */#define MASK_VAL_READ(reg, val) (((val) >> (reg)->bit_offset) & \ GENMASK(((reg)->bit_width) - 1, 0))#define MASK_VAL_WRITE(reg, prev_val, val) \ ((((val) & GENMASK(((reg)->bit_width) - 1, 0)) << (reg)->bit_offset) | \ ((prev_val) & ~(GENMASK(((reg)->bit_width) - 1, 0) << (reg)->bit_offset))) \
static unsigned int cpc_reg_access_width(const struct cpc_reg *reg){ if (reg->access_width > 4) return 0;
if (reg->access_width) return 8U << (reg->access_width - 1);
return reg->bit_width;}
enum cpc_platform_quirk { CPC_QUIRK_PERF_LIMITED_OWNS_UNIT = BIT(0),};
static const struct acpi_platform_list cpc_platform_quirk_list[] = { { .oem_id = "NVIDIA", .oem_table_id = "T41", .table = ACPI_SIG_DSDT, .pred = all_versions, .reason = "Performance Limited owns its access unit", .data = CPC_QUIRK_PERF_LIMITED_OWNS_UNIT, }, { }};
static DEFINE_MUTEX(cpc_platform_quirk_lock);static bool cpc_platform_quirks_initialized;static u32 cpc_platform_quirks;
static int cpc_get_platform_quirks(u32 *quirks){ int idx, ret = 0;
mutex_lock(&cpc_platform_quirk_lock); if (!cpc_platform_quirks_initialized) { idx = acpi_match_platform_list(cpc_platform_quirk_list); if (idx < 0 && idx != -ENODEV) { ret = idx; goto out; } if (idx >= 0) cpc_platform_quirks = cpc_platform_quirk_list[idx].data; cpc_platform_quirks_initialized = true; } *quirks = cpc_platform_quirks;out: mutex_unlock(&cpc_platform_quirk_lock);
return ret;}
static void cpc_apply_platform_quirks(struct cpc_reg *reg, unsigned int reg_idx, u32 quirks){ unsigned int access_width;
if (!(quirks & CPC_QUIRK_PERF_LIMITED_OWNS_UNIT) || reg_idx != PERF_LIMITED || reg->space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY || reg->bit_width != 2 || reg->bit_offset) return;
access_width = cpc_reg_access_width(reg); if (access_width != 32) return;
reg->bit_width = access_width; pr_info_once("firmware quirk: Performance Limited owns its access unit, using Bit Width %u\n", access_width);}
static u64 cpc_sysmem_access_size(const struct cpc_register_resource *reg){ unsigned int width = cpc_reg_access_width(®->cpc_entry.reg);
if (width != 8 && width != 16 && width != 32 && width != 64) return 0;
return width / 8;}
static u64 cpc_sysmem_field_size(const struct cpc_reg *gas){ return DIV_ROUND_UP((u64)gas->bit_offset + gas->bit_width, 8);}
static u64 cpc_sysmem_claim_size(const struct cpc_register_resource *reg){ const struct cpc_reg *gas = ®->cpc_entry.reg; u64 access_size = cpc_sysmem_access_size(reg);
if (!gas->bit_width) return access_size;
return max(access_size, cpc_sysmem_field_size(gas));}
static bool cpc_reg_access_aligned(const struct cpc_reg *reg, u64 access_size){ /* x86 MMIO and port-I/O accessors support unaligned addresses. */ return IS_ENABLED(CONFIG_X86) || IS_ALIGNED(reg->address, access_size);}
static bool cpc_sysmem_access_units_overlap(const struct cpc_register_resource *a, const struct cpc_register_resource *b){ const struct cpc_reg *a_gas = &a->cpc_entry.reg; const struct cpc_reg *b_gas = &b->cpc_entry.reg; u64 a_size = cpc_sysmem_claim_size(a); u64 b_size = cpc_sysmem_claim_size(b);
/* Keep the conservative locking path for malformed access widths. */ if (!a_size || !b_size) return true;
if (a_gas->address < b_gas->address) return b_gas->address - a_gas->address < a_size;
return a_gas->address - b_gas->address < b_size;}
static bool cpc_reg_is_writable(unsigned int reg_idx){ /* Only controls written by this driver can be competing writers. */ switch (reg_idx) { case DESIRED_PERF: case MIN_PERF: case MAX_PERF: case PERF_LIMITED: case ENABLE: case AUTO_SEL_ENABLE: case AUTO_ACT_WINDOW: case ENERGY_PERF: return true; default: return false; }}
static bool cpc_reg_is_write_only(const struct cpc_desc *cpc_desc, unsigned int reg_idx){ return cpc_desc->version >= CPPC_V4_REV && (reg_idx == DESIRED_PERF || reg_idx == OSPM_NOMINAL_PERF);}
static void cpc_disable_reg(struct cpc_desc *cpc_desc, unsigned int reg_idx){ struct cpc_register_resource *reg = &cpc_desc->cpc_regs[reg_idx];
reg->type = ACPI_TYPE_INTEGER; reg->cpc_entry.int_value = 0;}
static bool cpc_optional_writer_can_be_disabled(unsigned int reg_idx){ if (!IS_OPTIONAL_CPC_REG(reg_idx) || !cpc_reg_is_writable(reg_idx) || reg_idx == MIN_PERF || reg_idx == MAX_PERF || reg_idx == ENABLE || reg_idx == AUTO_SEL_ENABLE) return false;
return true;}
static bool cpc_sysmem_reg_needs_rmw(const struct cpc_register_resource *reg){ const struct cpc_reg *gas = ®->cpc_entry.reg; u64 access_size = cpc_sysmem_access_size(reg);
return gas->bit_offset || gas->bit_width != access_size * 8;}
static int cpc_validate_sysmem_reg(struct cpc_desc *cpc_desc, const struct cpc_reg *gas, unsigned int reg_idx){ unsigned int access_width = cpc_reg_access_width(gas); u64 access_size;
if (access_width != 8 && access_width != 16 && access_width != 32 && access_width != 64) goto invalid;
if (!gas->bit_width || gas->bit_width > access_width || gas->bit_offset >= access_width || gas->bit_width > access_width - gas->bit_offset) goto invalid;
access_size = access_width / 8; if (!gas->address || gas->address > U64_MAX - (access_size - 1)) goto invalid; if (!cpc_reg_access_aligned(gas, access_size)) goto invalid;
if (reg_idx == PERF_LIMITED) { if (access_width == 64 && !IS_ENABLED(CONFIG_64BIT)) { pr_warn_once("CPU%d: Performance Limited register cannot be accessed atomically; keeping its range reserved\n", cpc_desc->cpu_id); cpc_desc->cpc_regs[reg_idx].cpc_entry.read_unsupported = true; cpc_desc->cpc_regs[reg_idx].cpc_entry.write_unsupported = true; return 0; }
if (gas->bit_offset || gas->bit_width != access_width) { pr_warn_once("CPU%d: Performance Limited register cannot be cleared safely; keeping it readable\n", cpc_desc->cpu_id); cpc_desc->cpc_regs[reg_idx].cpc_entry.write_unsupported = true; } }
return 0;
invalid: access_size = 0; if (access_width == 8 || access_width == 16 || access_width == 32 || access_width == 64) access_size = access_width / 8; if (gas->bit_width) access_size = max(access_size, cpc_sysmem_field_size(gas)); if ((cpc_reg_is_write_only(cpc_desc, reg_idx) || reg_idx == PERF_LIMITED) && gas->address && access_size && gas->address <= U64_MAX - (access_size - 1)) { struct cpc_register_resource *reg = &cpc_desc->cpc_regs[reg_idx];
if (reg_idx == PERF_LIMITED) pr_warn_once("CPU%d: _CPC v%d register %u is inaccessible; keeping its range reserved\n", cpc_desc->cpu_id, cpc_desc->version, reg_idx); else pr_warn("CPU%d: _CPC v%d register %u is inaccessible; keeping its range reserved\n", cpc_desc->cpu_id, cpc_desc->version, reg_idx); reg->cpc_entry.read_unsupported = true; reg->cpc_entry.write_unsupported = true; return 0; }
pr_debug("CPU:%d invalid SystemMemory GAS for _CPC register %u\n", cpc_desc->cpu_id, reg_idx); return -EINVAL;}
static bool cpc_immutable_autonomous(const struct cpc_desc *cpc_desc){ const struct cpc_register_resource *reg;
reg = &cpc_desc->cpc_regs[AUTO_SEL_ENABLE]; return osc_sb_cppc2_support_acked && reg->type == ACPI_TYPE_INTEGER && reg->cpc_entry.int_value == 1;}
static bool cpc_retain_pcc_status(struct cpc_desc *cpc_desc, unsigned int reg_idx);
static int cpc_resolve_unsupported(struct cpc_desc *cpc_desc, u32 unsupported){ unsigned int i; u32 bounds = BIT(MIN_PERF) | BIT(MAX_PERF); bool min_unusable, max_unusable;
if (unsupported & bounds) { min_unusable = (unsupported & BIT(MIN_PERF)) || !cpc_is_writable(&cpc_desc->cpc_regs[MIN_PERF]); max_unusable = (unsupported & BIT(MAX_PERF)) || !cpc_is_writable(&cpc_desc->cpc_regs[MAX_PERF]); if (min_unusable && max_unusable) { pr_warn("CPU%d: ignoring inaccessible Minimum and Maximum Performance registers\n", cpc_desc->cpu_id); cpc_disable_reg(cpc_desc, MIN_PERF); cpc_disable_reg(cpc_desc, MAX_PERF); unsupported &= ~bounds; } }
for (i = 0; i < cpc_desc->num_entries - 2; i++) { if (!(unsupported & BIT(i))) continue;
/* CPPC control does not depend on Performance Limited status. */ if (i == PERF_LIMITED) { if (CPC_IN_PCC(&cpc_desc->cpc_regs[i]) && cpc_retain_pcc_status(cpc_desc, i)) continue;
pr_warn_once("CPU%d: ignoring inaccessible Performance Limited register\n", cpc_desc->cpu_id); cpc_disable_reg(cpc_desc, i); continue; }
if (i == DESIRED_PERF && cpc_immutable_autonomous(cpc_desc)) { pr_warn("CPU%d: ignoring inaccessible Desired Performance register in autonomous mode\n", cpc_desc->cpu_id); cpc_disable_reg(cpc_desc, i); continue; }
/* * A present Enable or Autonomous Selection control must remain * usable. Disabling the latter could leave autonomous selection * enabled while OSPM believes that it has disabled it. */ if (i == ENABLE || (i == AUTO_SEL_ENABLE && cpc_entry_present(&cpc_desc->cpc_regs[i])) || i == MIN_PERF || i == MAX_PERF || !IS_OPTIONAL_CPC_REG(i)) { pr_err("CPU%d: cannot access _CPC register %u\n", cpc_desc->cpu_id, i); return -EINVAL; }
pr_warn("CPU%d: ignoring inaccessible optional _CPC register %u\n", cpc_desc->cpu_id, i); cpc_disable_reg(cpc_desc, i); }
return 0;}
static int cpc_validate_required_controls(struct cpc_desc *cpc_desc){ unsigned int i;
/* * Performance Limited is required by the specification, but tolerate a * NULL descriptor used by firmware which cannot report limiting events. * CPPC control does not depend on this status. */ for (i = 0; i < cpc_desc->num_entries - 2; i++) { if (i != DESIRED_PERF && i != PERF_LIMITED && !IS_OPTIONAL_CPC_REG(i) && !cpc_entry_present(&cpc_desc->cpc_regs[i])) { pr_debug("CPU:%d lacks mandatory _CPC register %u\n", cpc_desc->cpu_id, i); return -EINVAL; } }
/* Desired may be absent only for immutable autonomous operation. */ if (!cpc_is_writable(&cpc_desc->cpc_regs[DESIRED_PERF]) && !cpc_immutable_autonomous(cpc_desc)) { pr_debug("CPU:%d lacks a writable Desired Performance register\n", cpc_desc->cpu_id); return -EINVAL; }
return 0;}
static int cpc_validate_bound_controls(struct cpc_desc *cpc_desc){ bool have_min, have_max;
have_min = cpc_is_writable(&cpc_desc->cpc_regs[MIN_PERF]); have_max = cpc_is_writable(&cpc_desc->cpc_regs[MAX_PERF]); if (have_min != have_max) { pr_err("CPU%d: _CPC must provide both Minimum and Maximum Performance or neither\n", cpc_desc->cpu_id); return -EINVAL; }
return 0;}
static boolcpc_retain_pcc_status(struct cpc_desc *cpc_desc, unsigned int reg_idx){ struct cpc_register_resource *reg = &cpc_desc->cpc_regs[reg_idx]; const struct cpc_reg *gas = ®->cpc_entry.reg; u64 size;
if (reg_idx != PERF_LIMITED || !gas->bit_width) return false;
size = DIV_ROUND_UP((u64)gas->bit_offset + gas->bit_width, 8); if (!size || gas->address > U64_MAX - (size - 1)) return false;
reg->cpc_entry.read_unsupported = true; reg->cpc_entry.write_unsupported = true; pr_warn_once("CPU%d: Performance Limited register cannot be accessed; keeping its PCC range reserved\n", cpc_desc->cpu_id); return true;}
static boolcpc_retain_sysio_status(struct cpc_desc *cpc_desc, unsigned int reg_idx){ struct cpc_register_resource *reg = &cpc_desc->cpc_regs[reg_idx]; const struct cpc_reg *gas = ®->cpc_entry.reg;
if (reg_idx != PERF_LIMITED || !gas->bit_width) return false;
/* Retain any in-range portion for overlap validation only. */ if (gas->address > U16_MAX) return false;
pr_warn_once("CPU%d: Performance Limited register cannot be accessed; keeping its SystemIO range reserved\n", cpc_desc->cpu_id); reg->cpc_entry.read_unsupported = true; reg->cpc_entry.write_unsupported = true; return true;}
static u64 cpc_non_mmio_access_size(const struct cpc_register_resource *reg){ const struct cpc_reg *gas = ®->cpc_entry.reg;
if (gas->space_id == ACPI_ADR_SPACE_PLATFORM_COMM) return DIV_ROUND_UP((u64)gas->bit_offset + gas->bit_width, 8);
return max((u64)cpc_reg_access_width(gas) / 8, DIV_ROUND_UP((u64)gas->bit_offset + gas->bit_width, 8));}
static void cpc_validate_pcc_bounds(struct cpc_desc *cpc_desc, int pcc_ss_id, struct cppc_pcc_data *data, u32 *unsupported){ u64 shmem_size = data->pcc_channel->shmem_size; unsigned int i;
for (i = 0; i < cpc_desc->num_entries - 2; i++) { struct cpc_register_resource *reg = &cpc_desc->cpc_regs[i]; struct cpc_reg *gas; u64 access_size;
if ((*unsupported & BIT(i)) || !CPC_SUPPORTED(reg) || !CPC_IN_PCC(reg)) continue;
gas = ®->cpc_entry.reg; if (gas->access_width != pcc_ss_id) continue; access_size = cpc_non_mmio_access_size(reg); if (shmem_size >= CPC_PCC_HEADER_SIZE && gas->address <= shmem_size - CPC_PCC_HEADER_SIZE && access_size <= shmem_size - CPC_PCC_HEADER_SIZE - gas->address) continue;
pr_debug("CPU%d: _CPC register %u exceeds the PCC shared region\n", cpc_desc->cpu_id, i); *unsupported |= BIT(i); }}
static bool cpc_pcc_access_needed(const struct cpc_desc *cpc_desc){ unsigned int i;
for (i = 0; i < cpc_desc->num_entries - 2; i++) { const struct cpc_register_resource *reg = &cpc_desc->cpc_regs[i];
if (CPC_SUPPORTED(reg) && CPC_IN_PCC(reg) && (cpc_is_readable(reg) || cpc_is_writable(reg))) return true; }
return false;}
static bool cpc_non_mmio_overlap_conflicts(u8 space_id, bool a_writable, bool b_writable, bool a_write_only, bool b_write_only){ /* Only a write-only control can use a separate read-side port alias. */ if (space_id == ACPI_ADR_SPACE_SYSTEM_IO && a_writable != b_writable) return a_writable ? !a_write_only : !b_write_only;
return a_writable || b_writable;}
static boolcpc_sysio_perf_limited_conflicts(unsigned int a_idx, bool a_writable, unsigned int b_idx, bool b_writable){ return (a_idx == PERF_LIMITED && b_writable) || (b_idx == PERF_LIMITED && a_writable);}
static struct rb_root_cached *cpc_non_mmio_tree(u8 space_id, u8 pcc_ss_id){ if (space_id == ACPI_ADR_SPACE_PLATFORM_COMM) return &cpc_pcc_trees[pcc_ss_id]; if (space_id == ACPI_ADR_SPACE_SYSTEM_IO) return &cpc_sysio_tree; return NULL;}
static bool cpc_same_non_mmio_register(const struct cpc_non_mmio_node *a, const struct cpc_non_mmio_node *b){ const struct cpc_reg *a_gas = &a->desc->cpc_regs[a->reg_idx].cpc_entry.reg; const struct cpc_reg *b_gas = &b->desc->cpc_regs[b->reg_idx].cpc_entry.reg;
return a->space_id == b->space_id && a->pcc_ss_id == b->pcc_ss_id && a->reg_idx == b->reg_idx && a->start == b->start && a->last == b->last && a_gas->bit_offset == b_gas->bit_offset && a_gas->bit_width == b_gas->bit_width && (a->space_id == ACPI_ADR_SPACE_PLATFORM_COMM || cpc_reg_access_width(a_gas) == cpc_reg_access_width(b_gas));}
static int cpc_validate_non_mmio_pair(const struct cpc_non_mmio_node *a, const struct cpc_non_mmio_node *b){ const struct cpc_register_resource *a_reg; const struct cpc_register_resource *b_reg; bool a_writable, b_writable; const char *name;
a_reg = &a->desc->cpc_regs[a->reg_idx]; b_reg = &b->desc->cpc_regs[b->reg_idx]; a_writable = cpc_reg_is_writable(a->reg_idx) && cpc_is_writable(a_reg); b_writable = cpc_reg_is_writable(b->reg_idx) && cpc_is_writable(b_reg);
if (!cpc_non_mmio_overlap_conflicts(a->space_id, a_writable, b_writable, cpc_reg_is_write_only(a->desc, a->reg_idx), cpc_reg_is_write_only(b->desc, b->reg_idx)) && !(a->space_id == ACPI_ADR_SPACE_SYSTEM_IO && cpc_sysio_perf_limited_conflicts(a->reg_idx, a_writable, b->reg_idx, b_writable))) return 0;
if (cpc_same_non_mmio_register(a, b)) return 0;
name = a->space_id == ACPI_ADR_SPACE_PLATFORM_COMM ? "PCC" : "SystemIO"; pr_err("CPU%d: %s _CPC register %u conflicts with CPU%d register %u\n", a->desc->cpu_id, name, a->reg_idx, b->desc->cpu_id, b->reg_idx); return -EINVAL;}
static void cpc_unregister_non_mmio_desc_locked(struct cpc_desc *cpc_desc){ unsigned int i;
if (!cpc_desc->non_mmio_nodes) return;
for (i = 0; i < cpc_desc->num_entries - 2; i++) { struct cpc_non_mmio_node *node = &cpc_desc->non_mmio_nodes[i]; struct rb_root_cached *tree;
if (!node->registered) continue;
tree = cpc_non_mmio_tree(node->space_id, node->pcc_ss_id); cpc_non_mmio_itree_remove(node, tree); }
kfree(cpc_desc->non_mmio_nodes); cpc_desc->non_mmio_nodes = NULL;}
static int cpc_register_non_mmio_desc(struct cpc_desc *cpc_desc){ unsigned int nr_regs = cpc_desc->num_entries - 2; unsigned int i; int ret = 0; bool found = false;
for (i = 0; i < nr_regs; i++) { struct cpc_register_resource *reg = &cpc_desc->cpc_regs[i]; u8 space_id;
if (!CPC_SUPPORTED(reg) || reg->type != ACPI_TYPE_BUFFER) continue; space_id = reg->cpc_entry.reg.space_id; if (space_id == ACPI_ADR_SPACE_PLATFORM_COMM || space_id == ACPI_ADR_SPACE_SYSTEM_IO) { found = true; break; } } if (!found) return 0;
cpc_desc->non_mmio_nodes = kcalloc(nr_regs, sizeof(*cpc_desc->non_mmio_nodes), GFP_KERNEL); if (!cpc_desc->non_mmio_nodes) return -ENOMEM;
mutex_lock(&cpc_non_mmio_lock);
for (i = 0; i < nr_regs; i++) { struct cpc_register_resource *reg = &cpc_desc->cpc_regs[i]; struct cpc_non_mmio_node *match, *node; struct rb_root_cached *tree; u8 space_id; u64 size;
if (!CPC_SUPPORTED(reg) || reg->type != ACPI_TYPE_BUFFER) continue;
space_id = reg->cpc_entry.reg.space_id; if (space_id != ACPI_ADR_SPACE_PLATFORM_COMM && space_id != ACPI_ADR_SPACE_SYSTEM_IO) continue;
node = &cpc_desc->non_mmio_nodes[i]; size = cpc_non_mmio_access_size(reg); node->start = reg->cpc_entry.reg.address; node->last = node->start + size - 1; node->desc = cpc_desc; node->reg_idx = i; node->space_id = space_id; node->pcc_ss_id = space_id == ACPI_ADR_SPACE_PLATFORM_COMM ? reg->cpc_entry.reg.access_width : 0; tree = cpc_non_mmio_tree(space_id, node->pcc_ss_id);
match = cpc_non_mmio_itree_iter_first(tree, node->start, node->last); while (match) { ret = cpc_validate_non_mmio_pair(node, match); if (ret) goto out_unregister;
match = cpc_non_mmio_itree_iter_next(match, node->start, node->last); } cpc_non_mmio_itree_insert(node, tree); node->registered = true; }
mutex_unlock(&cpc_non_mmio_lock); return 0;
out_unregister: cpc_unregister_non_mmio_desc_locked(cpc_desc); mutex_unlock(&cpc_non_mmio_lock); return ret;}
static void cpc_unregister_non_mmio_desc(struct cpc_desc *cpc_desc){ if (!cpc_desc->non_mmio_nodes) return;
mutex_lock(&cpc_non_mmio_lock); cpc_unregister_non_mmio_desc_locked(cpc_desc); mutex_unlock(&cpc_non_mmio_lock);}
static void cpc_mark_rmw_lock_users(struct cpc_desc *cpc_desc){ int i;
for (i = 0; i < cpc_desc->num_entries - 2; i++) { struct cpc_register_resource *reg = &cpc_desc->cpc_regs[i];
if (CPC_SUPPORTED(reg) && CPC_IN_SYSTEM_MEMORY(reg) && cpc_is_writable(reg)) reg->cpc_entry.use_rmw_lock = cpc_sysmem_reg_needs_rmw(reg); }}
struct cpc_bit_position { u64 byte; u8 bit;};
static bool cpc_bit_position_before(const struct cpc_bit_position *a, const struct cpc_bit_position *b){ return a->byte < b->byte || (a->byte == b->byte && a->bit < b->bit);}
static bool cpc_sysmem_fields_overlap(const struct cpc_register_resource *a, const struct cpc_register_resource *b){ const struct cpc_reg *a_gas = &a->cpc_entry.reg; const struct cpc_reg *b_gas = &b->cpc_entry.reg; unsigned int a_last_bit = a_gas->bit_offset + a_gas->bit_width - 1; unsigned int b_last_bit = b_gas->bit_offset + b_gas->bit_width - 1; struct cpc_bit_position a_start = { .byte = a_gas->address + a_gas->bit_offset / 8, .bit = a_gas->bit_offset % 8, }; struct cpc_bit_position a_end = { .byte = a_gas->address + a_last_bit / 8, .bit = a_last_bit % 8, }; struct cpc_bit_position b_start = { .byte = b_gas->address + b_gas->bit_offset / 8, .bit = b_gas->bit_offset % 8, }; struct cpc_bit_position b_end = { .byte = b_gas->address + b_last_bit / 8, .bit = b_last_bit % 8, };
return !cpc_bit_position_before(&a_end, &b_start) && !cpc_bit_position_before(&b_end, &a_start);}
static bool cpc_sysmem_access_overlaps_field(const struct cpc_register_resource *access, const struct cpc_register_resource *field){ const struct cpc_reg *access_gas = &access->cpc_entry.reg; const struct cpc_reg *field_gas = &field->cpc_entry.reg; u64 access_last; u64 field_start; u64 field_last;
if (!field_gas->bit_width) return cpc_sysmem_access_units_overlap(access, field);
access_last = access_gas->address + cpc_sysmem_access_size(access) - 1; field_start = field_gas->address + field_gas->bit_offset / 8; field_last = field_gas->address + (field_gas->bit_offset + field_gas->bit_width - 1) / 8;
return access_gas->address <= field_last && field_start <= access_last;}
static bool cpc_same_sysmem_register(unsigned int a_idx, const struct cpc_register_resource *a, unsigned int b_idx, const struct cpc_register_resource *b){ const struct cpc_reg *a_gas = &a->cpc_entry.reg; const struct cpc_reg *b_gas = &b->cpc_entry.reg;
return a_idx == b_idx && a_gas->address == b_gas->address && a_gas->bit_width == b_gas->bit_width && a_gas->bit_offset == b_gas->bit_offset && cpc_reg_access_width(a_gas) == cpc_reg_access_width(b_gas);}
static int cpc_validate_sysmem_pair(const struct cpc_desc *a_desc, unsigned int a_idx, const struct cpc_desc *b_desc, unsigned int b_idx){ const struct cpc_register_resource *a = &a_desc->cpc_regs[a_idx]; const struct cpc_register_resource *b = &b_desc->cpc_regs[b_idx]; bool a_write_only, b_write_only; bool a_writable, b_writable; bool fields_overlap;
/* The overlap helper includes each descriptor's conservative claim. */ if (!CPC_SUPPORTED(a) || !CPC_IN_SYSTEM_MEMORY(a) || !CPC_SUPPORTED(b) || !CPC_IN_SYSTEM_MEMORY(b) || !cpc_sysmem_access_units_overlap(a, b)) return 0;
a_write_only = cpc_reg_is_write_only(a_desc, a_idx); b_write_only = cpc_reg_is_write_only(b_desc, b_idx); fields_overlap = !a->cpc_entry.reg.bit_width || !b->cpc_entry.reg.bit_width || cpc_sysmem_fields_overlap(a, b); /* A readable field must not expose another field's undefined bits. */ if (a_write_only != b_write_only && cpc_is_readable(a_write_only ? b : a) && fields_overlap) goto conflict;
a_writable = cpc_reg_is_writable(a_idx) && cpc_is_writable(a); b_writable = cpc_reg_is_writable(b_idx) && cpc_is_writable(b); if (!a_writable && !b_writable) return 0;
if (cpc_same_sysmem_register(a_idx, a, b_idx, b)) { u64 access_size = cpc_sysmem_access_size(a);
/* * Exact partial aliases update the same field and retain * last-writer-wins semantics when the complete access is one native * transaction. A 64-bit MMIO write may be split on 32-bit kernels, * and an unaligned x86 access is not guaranteed to be one device * transaction. */ if (!a_writable || (IS_ALIGNED(a->cpc_entry.reg.address, access_size) && (access_size < sizeof(u64) || IS_ENABLED(CONFIG_64BIT)))) return 0; goto conflict; }
/* * The platform may set Performance Limited asynchronously. A write to * another field in the same access unit could write back stale status * bits, which an OSPM lock cannot prevent. */ if ((a_idx == PERF_LIMITED && b_writable) || (b_idx == PERF_LIMITED && a_writable)) goto conflict;
/* A full-width writer must not overwrite another logical field. */ if (fields_overlap && ((a_writable && b_writable) || (a_writable && !cpc_sysmem_reg_needs_rmw(a)) || (b_writable && !cpc_sysmem_reg_needs_rmw(b)))) goto conflict;
/* Different descriptors do not share their partial-write locks. */ if (a_desc != b_desc && a_writable && b_writable) goto conflict;
/* * RMW of either writer preserves the other field. If that field is * write-only, its readback is undefined and cannot safely be replayed. */ if ((a_write_only && b_writable && cpc_sysmem_reg_needs_rmw(b) && cpc_sysmem_access_overlaps_field(b, a)) || (b_write_only && a_writable && cpc_sysmem_reg_needs_rmw(a) && cpc_sysmem_access_overlaps_field(a, b))) goto conflict;
return 0;
conflict: pr_err("CPU%d: SystemMemory _CPC register %u conflicts with CPU%d register %u\n", a_desc->cpu_id, a_idx, b_desc->cpu_id, b_idx); return -EINVAL;}
static bool cpc_disable_new_sysmem_writer(struct cpc_desc *cpc_desc, unsigned int reg_idx, const struct cpc_sysmem_node *node){ struct cpc_register_resource *reg = &cpc_desc->cpc_regs[reg_idx]; struct cpc_sysmem_node *match; unsigned int status_cpu = 0; bool found = false;
if (!cpc_optional_writer_can_be_disabled(reg_idx) || !cpc_is_writable(reg)) return false;
match = cpc_sysmem_first(node->start, node->last); while (match) { const struct cpc_register_resource *status;
if (match->reg_idx == PERF_LIMITED) { status = &match->desc->cpc_regs[PERF_LIMITED]; if (!status->cpc_entry.reg.bit_width || cpc_sysmem_fields_overlap(reg, status)) return false; status_cpu = match->desc->cpu_id; found = true; }
match = cpc_sysmem_next(match, node->start, node->last); } if (!found) return false;
pr_warn_once("CPU%d: ignoring optional _CPC register %u sharing CPU%d Performance Limited access unit\n", cpc_desc->cpu_id, reg_idx, status_cpu); cpc_disable_reg(cpc_desc, reg_idx); return true;}
static void cpc_unregister_sysmem_desc_locked(struct cpc_desc *cpc_desc){ unsigned int i;
if (!cpc_desc->sysmem_nodes) return;
for (i = 0; i < cpc_desc->num_entries - 2; i++) { struct cpc_sysmem_node *node = &cpc_desc->sysmem_nodes[i]; struct cpc_sysmem_node *alias, *child;
if (node->alias_of) { list_del(&node->alias_node); continue; } if (!node->registered) continue;
cpc_sysmem_itree_remove(node, &cpc_sysmem_tree); node->registered = false; if (list_empty(&node->aliases)) continue;
/* Keep one representative for aliases owned by live descriptors. */ alias = list_first_entry(&node->aliases, struct cpc_sysmem_node, alias_node); list_del_init(&alias->alias_node); alias->alias_of = NULL; alias->registered = true; list_splice_init(&node->aliases, &alias->aliases); list_for_each_entry(child, &alias->aliases, alias_node) child->alias_of = alias; cpc_sysmem_itree_insert(alias, &cpc_sysmem_tree); }
kfree(cpc_desc->sysmem_nodes); cpc_desc->sysmem_nodes = NULL;}
static int cpc_register_sysmem_desc(struct cpc_desc *cpc_desc){ unsigned int nr_regs = cpc_desc->num_entries - 2; unsigned int i; int ret = 0; bool found = false;
for (i = 0; i < nr_regs; i++) { struct cpc_register_resource *reg = &cpc_desc->cpc_regs[i];
if (CPC_SUPPORTED(reg) && CPC_IN_SYSTEM_MEMORY(reg)) { found = true; break; } } if (!found) return 0;
cpc_desc->sysmem_nodes = kcalloc(nr_regs, sizeof(*cpc_desc->sysmem_nodes), GFP_KERNEL); if (!cpc_desc->sysmem_nodes) return -ENOMEM;
mutex_lock(&cpc_sysmem_lock);
for (i = 0; i < nr_regs; i++) { struct cpc_register_resource *reg = &cpc_desc->cpc_regs[i]; struct cpc_sysmem_node *alias = NULL, *match, *node; u64 size;
if (!CPC_SUPPORTED(reg) || !CPC_IN_SYSTEM_MEMORY(reg)) continue;
node = &cpc_desc->sysmem_nodes[i]; size = cpc_sysmem_claim_size(reg); node->start = reg->cpc_entry.reg.address; node->last = node->start + size - 1; node->desc = cpc_desc; node->reg_idx = i; INIT_LIST_HEAD(&node->aliases); INIT_LIST_HEAD(&node->alias_node);
/* Performance Limited precedes every optional writer we may disable. */ if (cpc_disable_new_sysmem_writer(cpc_desc, i, node)) continue;
match = cpc_sysmem_first(node->start, node->last); while (match) { struct cpc_register_resource *match_reg;
match_reg = &match->desc->cpc_regs[match->reg_idx]; ret = cpc_validate_sysmem_pair(cpc_desc, i, match->desc, match->reg_idx); if (ret) goto out_unregister; if (cpc_desc == match->desc) { reg->cpc_entry.use_rmw_lock = true; match_reg->cpc_entry.use_rmw_lock = true; } if (cpc_same_sysmem_register(i, reg, match->reg_idx, match_reg)) alias = match;
match = cpc_sysmem_next(match, node->start, node->last); } if (alias) { node->alias_of = alias; list_add_tail(&node->alias_node, &alias->aliases); continue; }
cpc_sysmem_itree_insert(node, &cpc_sysmem_tree); node->registered = true; }
mutex_unlock(&cpc_sysmem_lock); return 0;
out_unregister: cpc_unregister_sysmem_desc_locked(cpc_desc); mutex_unlock(&cpc_sysmem_lock); return ret;}
static void cpc_unregister_sysmem_desc(struct cpc_desc *cpc_desc){ if (!cpc_desc->sysmem_nodes) return;
mutex_lock(&cpc_sysmem_lock); cpc_unregister_sysmem_desc_locked(cpc_desc); mutex_unlock(&cpc_sysmem_lock);}
static ssize_t show_feedback_ctrs(struct kobject *kobj, struct kobj_attribute *attr, char *buf){ struct cpc_desc *cpc_ptr = to_cpc_desc(kobj); struct cppc_perf_fb_ctrs fb_ctrs = {0}; int ret;
ret = cppc_get_perf_ctrs(cpc_ptr->cpu_id, &fb_ctrs); if (ret) return ret;
return sysfs_emit(buf, "ref:%llu del:%llu\n", fb_ctrs.reference, fb_ctrs.delivered);}define_one_cppc_ro(feedback_ctrs);
static struct attribute *cppc_attrs[] = { &feedback_ctrs.attr, &reference_perf.attr, &wraparound_time.attr, &highest_perf.attr, &lowest_perf.attr, &lowest_nonlinear_perf.attr, &guaranteed_perf.attr, &nominal_perf.attr, &nominal_freq.attr, &lowest_freq.attr, NULL};ATTRIBUTE_GROUPS(cppc);
static void cppc_free_desc(struct cpc_desc *cpc_ptr){ unsigned int i;
cpc_unregister_non_mmio_desc(cpc_ptr); cpc_unregister_sysmem_desc(cpc_ptr);
for (i = 2; i < cpc_ptr->num_entries; i++) { void __iomem *addr = cpc_ptr->cpc_regs[i - 2].sys_mem_vaddr;
if (addr) iounmap(addr); }
kfree(cpc_ptr);}
static void cppc_kobj_release(struct kobject *kobj){ cppc_free_desc(to_cpc_desc(kobj));}
static const struct kobj_type cppc_ktype = { .release = cppc_kobj_release, .sysfs_ops = &kobj_sysfs_ops, .default_groups = cppc_groups,};
static int check_pcc_chan(int pcc_ss_id, bool chk_err_bit){ int ret, status; struct cppc_pcc_data *pcc_ss_data = pcc_data[pcc_ss_id]; struct acpi_pcct_shared_memory __iomem *generic_comm_base = pcc_ss_data->pcc_channel->shmem;
if (!pcc_ss_data->platform_owns_pcc) return 0;
/* * Poll PCC status register every 3us(delay_us) for maximum of * deadline_us(timeout_us) until PCC command complete bit is set(cond) */ ret = readw_relaxed_poll_timeout(&generic_comm_base->status, status, status & PCC_CMD_COMPLETE_MASK, 3, pcc_ss_data->deadline_us);
if (likely(!ret)) { /* Order completion status before reading the returned payload. */ rmb(); pcc_ss_data->platform_owns_pcc = false; if (chk_err_bit && (status & PCC_ERROR_MASK)) ret = -EIO; }
if (unlikely(ret)) pr_err("PCC check channel failed for ss: %d. ret=%d\n", pcc_ss_id, ret);
return ret;}
static void cppc_complete_pcc_write(int pcc_ss_id, struct cppc_pcc_data *pcc_ss_data, int ret){ int i;
if (unlikely(ret)) { for_each_possible_cpu(i) { struct cpc_desc *desc = per_cpu(cpc_desc_ptr, i);
if (!desc || per_cpu(cpu_pcc_subspace_idx, i) != pcc_ss_id) continue;
if (desc->write_cmd_id == pcc_ss_data->pcc_write_cnt) desc->write_cmd_status = ret; } }
pcc_ss_data->pcc_write_cnt++; wake_up_all(&pcc_ss_data->pcc_write_wait_q);}
/* The caller must hold pcc_lock for write. */static void cppc_abort_pending_pcc_write(int pcc_ss_id, struct cppc_pcc_data *pcc_ss_data, int ret){ if (!pcc_ss_data->pending_pcc_write_cmd) return;
pcc_ss_data->pending_pcc_write_cmd = false; cppc_complete_pcc_write(pcc_ss_id, pcc_ss_data, ret);}
/* * This function transfers the ownership of the PCC to the platform * So it must be called while holding write_lock(pcc_lock) */static int send_pcc_cmd(int pcc_ss_id, u16 cmd){ int ret = -EIO; struct cppc_pcc_data *pcc_ss_data = pcc_data[pcc_ss_id]; struct acpi_pcct_shared_memory __iomem *generic_comm_base = pcc_ss_data->pcc_channel->shmem; unsigned int time_delta;
/* * For CMD_WRITE we know for a fact the caller should have checked * the channel before writing to PCC space */ if (cmd == CMD_READ) { /* * If there are pending cpc_writes, then we stole the channel * before write completion, so first send a WRITE command to * platform */ if (pcc_ss_data->pending_pcc_write_cmd) send_pcc_cmd(pcc_ss_id, CMD_WRITE);
ret = check_pcc_chan(pcc_ss_id, false); if (ret) goto end; } else /* CMD_WRITE */ pcc_ss_data->pending_pcc_write_cmd = FALSE;
/* * Handle the Minimum Request Turnaround Time(MRTT) * "The minimum amount of time that OSPM must wait after the completion * of a command before issuing the next command, in microseconds" */ if (pcc_ss_data->pcc_mrtt) { time_delta = ktime_us_delta(ktime_get(), pcc_ss_data->last_cmd_cmpl_time); if (pcc_ss_data->pcc_mrtt > time_delta) udelay(pcc_ss_data->pcc_mrtt - time_delta); }
/* * Handle the non-zero Maximum Periodic Access Rate(MPAR) * "The maximum number of periodic requests that the subspace channel can * support, reported in commands per minute. 0 indicates no limitation." * * This parameter should be ideally zero or large enough so that it can * handle maximum number of requests that all the cores in the system can * collectively generate. If it is not, we will follow the spec and just * not send the request to the platform after hitting the MPAR limit in * any 60s window */ if (pcc_ss_data->pcc_mpar) { if (pcc_ss_data->mpar_count == 0) { time_delta = ktime_ms_delta(ktime_get(), pcc_ss_data->last_mpar_reset); if ((time_delta < 60 * MSEC_PER_SEC) && pcc_ss_data->last_mpar_reset) { pr_debug("PCC cmd for subspace %d not sent due to MPAR limit", pcc_ss_id); ret = -EIO; goto end; } pcc_ss_data->last_mpar_reset = ktime_get(); pcc_ss_data->mpar_count = pcc_ss_data->pcc_mpar; } pcc_ss_data->mpar_count--; }
/* Write to the shared comm region. */ writew_relaxed(cmd, &generic_comm_base->command);
/* Flip CMD COMPLETE bit */ writew_relaxed(0, &generic_comm_base->status);
pcc_ss_data->platform_owns_pcc = true;
/* Ring doorbell */ ret = mbox_send_message(pcc_ss_data->pcc_channel->mchan, &cmd); if (ret < 0) { pr_err("Err sending PCC mbox message. ss: %d cmd:%d, ret:%d\n", pcc_ss_id, cmd, ret); goto end; }
/* wait for completion and check for PCC error bit */ ret = check_pcc_chan(pcc_ss_id, true);
if (pcc_ss_data->pcc_mrtt) pcc_ss_data->last_cmd_cmpl_time = ktime_get();
if (pcc_ss_data->pcc_channel->mchan->mbox->txdone_irq) mbox_chan_txdone(pcc_ss_data->pcc_channel->mchan, ret); else mbox_client_txdone(pcc_ss_data->pcc_channel->mchan, ret);
end: if (cmd == CMD_WRITE) cppc_complete_pcc_write(pcc_ss_id, pcc_ss_data, ret);
return ret;}
static void cppc_chan_tx_done(struct mbox_client *cl, void *msg, int ret){ if (ret < 0) pr_debug("TX did not complete: CMD sent:%x, ret:%d\n", *(u16 *)msg, ret); else pr_debug("TX completed. CMD sent:%x, ret:%d\n", *(u16 *)msg, ret);}
static struct mbox_client cppc_mbox_cl = { .tx_done = cppc_chan_tx_done, .knows_txdone = true,};
static int acpi_get_psd(struct cpc_desc *cpc_ptr, acpi_handle handle){ int result = -EFAULT; acpi_status status = AE_OK; struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL}; struct acpi_buffer format = {sizeof("NNNNN"), "NNNNN"}; struct acpi_buffer state = {0, NULL}; union acpi_object *psd = NULL; struct acpi_psd_package *pdomain;
status = acpi_evaluate_object_typed(handle, "_PSD", NULL, &buffer, ACPI_TYPE_PACKAGE); if (status == AE_NOT_FOUND) /* _PSD is optional */ return 0; if (ACPI_FAILURE(status)) return -ENODEV;
psd = buffer.pointer; if (!psd || psd->package.count != 1) { pr_debug("Invalid _PSD data\n"); goto end; }
pdomain = &(cpc_ptr->domain_info);
state.length = sizeof(struct acpi_psd_package); state.pointer = pdomain;
status = acpi_extract_package(&(psd->package.elements[0]), &format, &state); if (ACPI_FAILURE(status)) { pr_debug("Invalid _PSD data for CPU:%d\n", cpc_ptr->cpu_id); goto end; }
if (pdomain->num_entries != ACPI_PSD_REV0_ENTRIES) { pr_debug("Unknown _PSD:num_entries for CPU:%d\n", cpc_ptr->cpu_id); goto end; }
if (pdomain->revision != ACPI_PSD_REV0_REVISION) { pr_debug("Unknown _PSD:revision for CPU: %d\n", cpc_ptr->cpu_id); goto end; }
if (pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ALL && pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ANY && pdomain->coord_type != DOMAIN_COORD_TYPE_HW_ALL) { pr_debug("Invalid _PSD:coord_type for CPU:%d\n", cpc_ptr->cpu_id); goto end; }
result = 0;end: kfree(buffer.pointer); return result;}
bool acpi_cpc_valid(void){ struct cpc_desc *cpc_ptr; int cpu;
if (acpi_disabled) return false;
for_each_online_cpu(cpu) { cpc_ptr = per_cpu(cpc_desc_ptr, cpu); if (!cpc_ptr) return false; }
return true;}EXPORT_SYMBOL_GPL(acpi_cpc_valid);
bool cppc_allow_fast_switch(const struct cpumask *cpus){ struct cpc_register_resource *desired_reg, *min_reg, *max_reg; struct cpc_desc *cpc_ptr; int cpu;
for_each_cpu(cpu, cpus) { cpc_ptr = per_cpu(cpc_desc_ptr, cpu); if (!cpc_ptr) return false; desired_reg = &cpc_ptr->cpc_regs[DESIRED_PERF]; min_reg = &cpc_ptr->cpc_regs[MIN_PERF]; max_reg = &cpc_ptr->cpc_regs[MAX_PERF];
if (!cpc_is_writable(desired_reg) || (!CPC_IN_SYSTEM_MEMORY(desired_reg) && !CPC_IN_SYSTEM_IO(desired_reg)) || (CPC_SUPPORTED(min_reg) && !CPC_IN_SYSTEM_MEMORY(min_reg) && !CPC_IN_SYSTEM_IO(min_reg)) || (CPC_SUPPORTED(max_reg) && !CPC_IN_SYSTEM_MEMORY(max_reg) && !CPC_IN_SYSTEM_IO(max_reg))) return false; }
return true;}EXPORT_SYMBOL_GPL(cppc_allow_fast_switch);
/** * acpi_get_psd_map - Map the CPUs in the freq domain of a given cpu * @cpu: Find all CPUs that share a domain with cpu. * @cpu_data: Pointer to CPU specific CPPC data including PSD info. * * Return: 0 for success or negative value for err. */int acpi_get_psd_map(unsigned int cpu, struct cppc_cpudata *cpu_data){ struct cpc_desc *cpc_ptr, *match_cpc_ptr; struct acpi_psd_package *match_pdomain; struct acpi_psd_package *pdomain; int count_target, i;
/* * Now that we have _PSD data from all CPUs, let's setup P-state * domain info. */ cpc_ptr = per_cpu(cpc_desc_ptr, cpu); if (!cpc_ptr) return -EFAULT;
pdomain = &(cpc_ptr->domain_info); cpumask_set_cpu(cpu, cpu_data->shared_cpu_map); if (pdomain->num_processors <= 1) return 0;
/* Validate the Domain info */ count_target = pdomain->num_processors; if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ALL) cpu_data->shared_type = CPUFREQ_SHARED_TYPE_ALL; else if (pdomain->coord_type == DOMAIN_COORD_TYPE_HW_ALL) cpu_data->shared_type = CPUFREQ_SHARED_TYPE_HW; else if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ANY) cpu_data->shared_type = CPUFREQ_SHARED_TYPE_ANY;
for_each_possible_cpu(i) { if (i == cpu) continue;
match_cpc_ptr = per_cpu(cpc_desc_ptr, i); if (!match_cpc_ptr) continue;
match_pdomain = &(match_cpc_ptr->domain_info); if (match_pdomain->domain != pdomain->domain) continue;
/* Here i and cpu are in the same domain */ if (match_pdomain->num_processors != count_target) goto err_fault;
if (pdomain->coord_type != match_pdomain->coord_type) goto err_fault;
cpumask_set_cpu(i, cpu_data->shared_cpu_map); }
return 0;
err_fault: /* Assume no coordination on any error parsing domain info */ cpumask_clear(cpu_data->shared_cpu_map); cpumask_set_cpu(cpu, cpu_data->shared_cpu_map); cpu_data->shared_type = CPUFREQ_SHARED_TYPE_NONE;
return -EFAULT;}EXPORT_SYMBOL_GPL(acpi_get_psd_map);
static int register_pcc_channel(int pcc_ss_idx){ struct cppc_pcc_data *data; struct pcc_mbox_chan *pcc_chan; u64 usecs_lat; int ret = 0;
if (pcc_ss_idx < 0 || pcc_ss_idx >= MAX_PCC_SUBSPACES) return -EINVAL;
mutex_lock(&pcc_data_lock); data = pcc_data[pcc_ss_idx]; if (!data) { ret = -ENODEV; goto out_unlock; } if (data->pcc_channel_acquired) goto out_unlock;
pcc_chan = pcc_mbox_request_channel(&cppc_mbox_cl, pcc_ss_idx); if (IS_ERR(pcc_chan)) { ret = -ENODEV; goto out_unlock; }
data->pcc_channel = pcc_chan; /* * cppc_ss->latency is just a Nominal value. In reality * the remote processor could be much slower to reply. * So add an arbitrary amount of wait on top of Nominal. */ usecs_lat = NUM_RETRIES * pcc_chan->latency; data->deadline_us = usecs_lat; data->pcc_mrtt = pcc_chan->min_turnaround_time; data->pcc_mpar = pcc_chan->max_access_rate; data->pcc_nominal = pcc_chan->latency; init_rwsem(&data->pcc_lock); init_waitqueue_head(&data->pcc_write_wait_q);
/* Reuse this channel when another CPU references the same subspace. */ data->pcc_channel_acquired = true;
out_unlock: mutex_unlock(&pcc_data_lock); return ret;}
/** * cpc_ffh_supported() - check if FFH reading supported * * Check if the architecture has support for functional fixed hardware * read/write capability. * * Return: true for supported, false for not supported */bool __weak cpc_ffh_supported(void){ return false;}
/** * cpc_supported_by_cpu() - check if CPPC is supported by CPU * * Check if the architectural support for CPPC is present even * if the _OSC hasn't prescribed it * * Return: true for supported, false for not supported */bool __weak cpc_supported_by_cpu(void){ return false;}
/** * pcc_data_alloc() - Allocate the pcc_data memory for pcc subspace * @pcc_ss_id: PCC Subspace index as in the PCC client ACPI package. * * Check and allocate the cppc_pcc_data memory. * In some processor configurations it is possible that same subspace * is shared between multiple CPUs. This is seen especially in CPUs * with hardware multi-threading support. * * Return: 0 for success, errno for failure */static int pcc_data_alloc(int pcc_ss_id){ struct cppc_pcc_data *data; int ret = 0;
if (pcc_ss_id < 0 || pcc_ss_id >= MAX_PCC_SUBSPACES) return -EINVAL;
mutex_lock(&pcc_data_lock); data = pcc_data[pcc_ss_id]; if (!data) { data = kzalloc_obj(struct cppc_pcc_data); if (!data) { ret = -ENOMEM; goto out_unlock; } raw_spin_lock_init(&data->payload_lock); pcc_data[pcc_ss_id] = data; } data->refcount++;
out_unlock: mutex_unlock(&pcc_data_lock); return ret;}
static void pcc_data_put(int pcc_ss_id){ struct cppc_pcc_data *data;
if (pcc_ss_id < 0 || pcc_ss_id >= MAX_PCC_SUBSPACES) return;
mutex_lock(&pcc_data_lock); data = pcc_data[pcc_ss_id]; if (!data || --data->refcount) goto out_unlock;
pcc_data[pcc_ss_id] = NULL; if (data->pcc_channel_acquired) pcc_mbox_free_channel(data->pcc_channel);
kfree(data);
out_unlock: mutex_unlock(&pcc_data_lock);}
/* * An example CPC table looks like the following. * * Name (_CPC, Package() { * 17, // NumEntries * 1, // Revision * ResourceTemplate() {Register(PCC, 32, 0, 0x120, 2)}, // Highest Performance * ResourceTemplate() {Register(PCC, 32, 0, 0x124, 2)}, // Nominal Performance * ResourceTemplate() {Register(PCC, 32, 0, 0x128, 2)}, // Lowest Nonlinear Performance * ResourceTemplate() {Register(PCC, 32, 0, 0x12C, 2)}, // Lowest Performance * ResourceTemplate() {Register(PCC, 32, 0, 0x130, 2)}, // Guaranteed Performance Register * ResourceTemplate() {Register(PCC, 32, 0, 0x110, 2)}, // Desired Performance Register * ResourceTemplate() {Register(SystemMemory, 0, 0, 0, 0)}, * ... * ... * ... * } * Each Register() encodes how to access that specific register. * e.g. a sample PCC entry has the following encoding: * * Register ( * PCC, // AddressSpaceKeyword * 8, // RegisterBitWidth * 8, // RegisterBitOffset * 0x30, // RegisterAddress * 9, // AccessSize (subspace ID) * ) */
/** * acpi_cppc_processor_probe - Search for per CPU _CPC objects. * @pr: Ptr to acpi_processor containing this CPU's logical ID. * * Return: 0 for success or negative value for err. */int acpi_cppc_processor_probe(struct acpi_processor *pr){ struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL}; union acpi_object *out_obj, *cpc_obj; struct cpc_desc *cpc_ptr; struct cpc_reg *gas_t; struct device *cpu_dev; acpi_handle handle = pr->handle; unsigned int num_ent, i, cpc_rev; u32 unsupported_regs = 0; u32 platform_quirks; int pcc_subspace_id = -1; bool pcc_data_ref = false; bool cpc_present = false; acpi_status status; int ret = -EINVAL; int err;
if (per_cpu(cpc_desc_ptr, pr->id)) return 0; ret = cpc_get_platform_quirks(&platform_quirks); if (ret) { pr_err("CPU%d: failed to match CPPC platform quirks: %d\n", pr->id, ret); return ret; } per_cpu(cpu_pcc_subspace_idx, pr->id) = -1;
if (!osc_sb_cppc2_support_acked) { pr_debug("CPPC v2 _OSC not acked\n"); if (!cpc_supported_by_cpu()) { pr_debug("CPPC is not supported by the CPU\n"); return -ENODEV; } }
/* Parse the ACPI _CPC table for this CPU. */ status = acpi_evaluate_object_typed(handle, "_CPC", NULL, &output, ACPI_TYPE_PACKAGE); if (ACPI_FAILURE(status)) { ret = -ENODEV; goto out_buf_free; } cpc_present = true; ret = -EINVAL;
out_obj = (union acpi_object *) output.pointer; if (out_obj->package.count < 2) { pr_debug("Unexpected _CPC package count (%u) for CPU:%d\n", out_obj->package.count, pr->id); goto out_buf_free; }
cpc_ptr = kzalloc_obj(struct cpc_desc); if (!cpc_ptr) { ret = -ENOMEM; goto out_buf_free; } cpc_ptr->cpu_id = pr->id;
/* First entry is NumEntries. */ cpc_obj = &out_obj->package.elements[0]; if (cpc_obj->type == ACPI_TYPE_INTEGER) { if (cpc_obj->integer.value < 2 || cpc_obj->integer.value > out_obj->package.count) { pr_debug("Invalid _CPC NumEntries (%llu) for package count (%u) on CPU:%d\n", cpc_obj->integer.value, out_obj->package.count, pr->id); goto out_free; }
num_ent = cpc_obj->integer.value; } else { pr_debug("Unexpected _CPC NumEntries entry type (%d) for CPU:%d\n", cpc_obj->type, pr->id); goto out_free; }
/* Second entry should be revision. */ cpc_obj = &out_obj->package.elements[1]; if (cpc_obj->type == ACPI_TYPE_INTEGER) { if (cpc_obj->integer.value > U8_MAX) { pr_debug("Invalid _CPC Revision (%llu) for CPU:%d\n", cpc_obj->integer.value, pr->id); ret = -EINVAL; goto out_free; } cpc_rev = cpc_obj->integer.value; } else { pr_debug("Unexpected _CPC Revision entry type (%d) for CPU:%d\n", cpc_obj->type, pr->id); goto out_free; }
if (cpc_rev < CPPC_V2_REV) { pr_debug("Unsupported _CPC Revision (%d) for CPU:%d\n", cpc_rev, pr->id); goto out_free; }
/* * Disregard _CPC if the number of entries in the return package is not * as expected, but support future revisions being proper supersets of * the v4 and only causing more entries to be returned by _CPC. */ if ((cpc_rev == CPPC_V2_REV && num_ent != CPPC_V2_NUM_ENT) || (cpc_rev == CPPC_V3_REV && num_ent != CPPC_V3_NUM_ENT) || (cpc_rev == CPPC_V4_REV && num_ent != CPPC_V4_NUM_ENT) || (cpc_rev > CPPC_V4_REV && num_ent <= CPPC_V4_NUM_ENT)) { pr_debug("Unexpected number of _CPC return package entries (%d) for CPU:%d\n", num_ent, pr->id); goto out_free; } if (cpc_rev > CPPC_V4_REV) { num_ent = CPPC_V4_NUM_ENT; cpc_rev = CPPC_V4_REV; }
cpc_ptr->num_entries = num_ent; cpc_ptr->version = cpc_rev;
/* Iterate through remaining entries in _CPC */ for (i = 2; i < num_ent; i++) { cpc_obj = &out_obj->package.elements[i];
if (cpc_obj->type == ACPI_TYPE_INTEGER) { bool legacy_null;
if (!cpc_integer_entry_valid(i - 2, cpc_obj->integer.value, &legacy_null)) { pr_debug("Invalid Integer _CPC register %u for CPU:%d\n", i - 2, pr->id); ret = -EINVAL; goto out_free; } if (legacy_null) pr_warn_once(FW_BUG "_CPC register %u uses Integer 0 for an absent Buffer\n", i - 2); cpc_ptr->cpc_regs[i - 2].type = ACPI_TYPE_INTEGER; cpc_ptr->cpc_regs[i - 2].cpc_entry.int_value = cpc_obj->integer.value; } else if (cpc_obj->type == ACPI_TYPE_BUFFER) { if (cpc_obj->buffer.length < sizeof(*gas_t)) { pr_debug("Invalid register descriptor for CPU:%d\n", pr->id); ret = -EINVAL; goto out_free; }
gas_t = (struct cpc_reg *) cpc_obj->buffer.pointer; if (gas_t->descriptor != CPC_GENERIC_REGISTER_DESCRIPTOR || gas_t->length != CPC_GENERIC_REGISTER_LENGTH) { pr_debug("Invalid register resource for CPU:%d\n", pr->id); ret = -EINVAL; goto out_free; }
cpc_ptr->cpc_regs[i - 2].type = ACPI_TYPE_BUFFER; memcpy(&cpc_ptr->cpc_regs[i - 2].cpc_entry.reg, gas_t, sizeof(*gas_t)); gas_t = &cpc_ptr->cpc_regs[i - 2].cpc_entry.reg; cpc_apply_platform_quirks(gas_t, i - 2, platform_quirks);
/* * The PCC Subspace index is encoded inside * the CPC table entries. The same PCC index * will be used for all the PCC entries, * so extract it only once. */ if (gas_t->space_id == ACPI_ADR_SPACE_PLATFORM_COMM) { /* These registers have no specified 32-bit upper bound. */ bool wide_write = i - 2 == PERF_LIMITED || i - 2 == ENABLE || i - 2 == AUTO_SEL_ENABLE; bool write_width_supported = gas_t->bit_width == 8 || gas_t->bit_width == 16 || gas_t->bit_width == 32 || gas_t->bit_width == 64; bool unsupported;
unsupported = !gas_t->bit_width || gas_t->bit_width > 64 || gas_t->bit_offset || gas_t->bit_width % 8 || (cpc_reg_is_writable(i - 2) && (!write_width_supported || (!wide_write && gas_t->bit_width > 32))); if (unsupported) { if (!cpc_retain_pcc_status(cpc_ptr, i - 2)) unsupported_regs |= BIT(i - 2); continue; }
if (pcc_subspace_id < 0) { pcc_subspace_id = gas_t->access_width; } else if (pcc_subspace_id != gas_t->access_width) { pr_debug("Mismatched PCC ids in _CPC for CPU:%d\n", pr->id); ret = -EINVAL; goto out_free; }
if (!pcc_data_ref) { err = pcc_data_alloc(pcc_subspace_id); if (err) { ret = err; goto out_free; } pcc_data_ref = true; } } else if (gas_t->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) { if (!IS_NULL_REG(gas_t)) { void __iomem *addr; size_t access_width;
err = cpc_validate_sysmem_reg(cpc_ptr, gas_t, i - 2); if (err) { unsupported_regs |= BIT(i - 2); continue; } if (!cpc_is_readable(&cpc_ptr->cpc_regs[i - 2]) && !cpc_is_writable(&cpc_ptr->cpc_regs[i - 2])) continue;
if (!osc_cpc_flexible_adr_space_confirmed) { pr_debug("Flexible address space capability not supported\n"); ret = -EOPNOTSUPP; if (!cpc_supported_by_cpu()) goto out_free; ret = -EINVAL; }
access_width = cpc_reg_access_width(gas_t); access_width /= 8; addr = ioremap(gas_t->address, access_width); if (!addr) { ret = -ENOMEM; goto out_free; } cpc_ptr->cpc_regs[i - 2].sys_mem_vaddr = addr; } } else if (gas_t->space_id == ACPI_ADR_SPACE_SYSTEM_IO) { u64 access_size; const char *reason = "uses unsupported SystemIO geometry"; unsigned int access_width; bool partial = false; bool unsupported;
access_width = cpc_reg_access_width(gas_t); unsupported = !IS_ENABLED(CONFIG_HAS_IOPORT); if (unsupported) reason = "requires unavailable SystemIO support"; else unsupported = access_width != 8 && access_width != 16 && access_width != 32; if (!unsupported) { access_size = access_width / 8; unsupported = !gas_t->bit_width || gas_t->bit_width > access_width || gas_t->bit_offset >= access_width || gas_t->bit_width > access_width - gas_t->bit_offset; partial = gas_t->bit_offset || gas_t->bit_width != access_width; } if (!unsupported) { unsupported = (cpc_reg_is_writable(i - 2) && i - 2 != PERF_LIMITED && cpc_is_writable(&cpc_ptr->cpc_regs[i - 2]) && partial) || !cpc_reg_access_aligned(gas_t, access_size) || gas_t->address > U16_MAX - (access_size - 1); } if (unsupported) { if (cpc_retain_sysio_status(cpc_ptr, i - 2)) continue; pr_debug("CPU%d: _CPC register %u %s\n", pr->id, i - 2, reason); unsupported_regs |= BIT(i - 2); continue; } if (i - 2 == PERF_LIMITED && partial) { pr_warn_once("CPU%d: Performance Limited register cannot be cleared safely; keeping it readable\n", cpc_ptr->cpu_id); cpc_ptr->cpc_regs[i - 2].cpc_entry.write_unsupported = true; } if (!osc_cpc_flexible_adr_space_confirmed) { pr_debug("Flexible address space capability not supported\n"); ret = -EOPNOTSUPP; if (!cpc_supported_by_cpu()) goto out_free; ret = -EINVAL; } } else { if (gas_t->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE || !cpc_ffh_supported()) { /* Support only PCC, SystemMemory, SystemIO, and FFH type regs. */ pr_debug("Unsupported register type (%d) in _CPC\n", gas_t->space_id); ret = -EOPNOTSUPP; goto out_free; } } } else if (cpc_obj->type == ACPI_TYPE_PACKAGE && (i - 2) == RESOURCE_PRIORITY) { /* * ACPI 6.6, s8.4.6.1.2.7 defines Resource Priority as a * Package of Resource Priority Register Descriptor sub-packages. * Parsing the full structure is not yet supported. * Mark the register as unsupported for now. */ pr_debug("CPU:%d Resource Priority not supported\n", pr->id); cpc_ptr->cpc_regs[i-2].type = ACPI_TYPE_INTEGER; cpc_ptr->cpc_regs[i-2].cpc_entry.int_value = 0; } else { pr_debug("Invalid entry type (%d) in _CPC for CPU:%d\n", i, pr->id); goto out_free; } }
per_cpu(cpu_pcc_subspace_idx, pr->id) = pcc_data_ref ? pcc_subspace_id : -1;
ret = cpc_resolve_unsupported(cpc_ptr, unsupported_regs); if (ret) goto out_free; unsupported_regs = 0;
ret = cpc_validate_required_controls(cpc_ptr); if (ret) goto out_free;
/* * Initialize the remaining cpc_regs as unsupported. * Example: In case FW exposes CPPC v2, the below loop will initialize * LOWEST_FREQ and NOMINAL_FREQ regs as unsupported */ for (i = num_ent - 2; i < MAX_CPC_REG_ENT; i++) { cpc_ptr->cpc_regs[i].type = ACPI_TYPE_INTEGER; cpc_ptr->cpc_regs[i].cpc_entry.int_value = 0; }
cpc_mark_rmw_lock_users(cpc_ptr); raw_spin_lock_init(&cpc_ptr->rmw_lock);
/* Parse PSD data for this CPU */ ret = acpi_get_psd(cpc_ptr, handle); if (ret) goto out_free;
ret = cpc_register_sysmem_desc(cpc_ptr); if (ret) goto out_free;
/* Register PCC channel once for all PCC subspace ID. */ if (pcc_data_ref) { ret = register_pcc_channel(pcc_subspace_id); if (ret) { pr_err("Failed to find PCC channel for subspace %d\n", pcc_subspace_id); goto out_free; }
cpc_validate_pcc_bounds(cpc_ptr, pcc_subspace_id, pcc_data[pcc_subspace_id], &unsupported_regs);
ret = cpc_resolve_unsupported(cpc_ptr, unsupported_regs); if (ret) goto out_free;
/* A range-only status entry needs the channel only for bounds. */ if (!cpc_pcc_access_needed(cpc_ptr)) { pcc_data_put(pcc_subspace_id); pcc_data_ref = false; per_cpu(cpu_pcc_subspace_idx, pr->id) = -1; } }
ret = cpc_validate_bound_controls(cpc_ptr); if (ret) goto out_free;
ret = cpc_register_non_mmio_desc(cpc_ptr); if (ret) goto out_free;
/* Everything looks okay */ pr_debug("Parsed CPC struct for CPU: %d\n", pr->id);
/* Add per logical CPU nodes for reading its feedback counters. */ cpu_dev = get_cpu_device(pr->id); if (!cpu_dev) { ret = -EINVAL; goto out_free; }
/* Plug PSD data into this CPU's CPC descriptor. */ cpc_set_desc(pr->id, cpc_ptr);
ret = kobject_init_and_add(&cpc_ptr->kobj, &cppc_ktype, &cpu_dev->kobj, "acpi_cppc"); if (ret) { cpc_set_desc(pr->id, NULL); cpc_unregister_non_mmio_desc(cpc_ptr); cpc_unregister_sysmem_desc(cpc_ptr); kobject_put(&cpc_ptr->kobj); goto out_pcc_put; }
kfree(output.pointer); return 0;
out_free: cppc_free_desc(cpc_ptr);
out_pcc_put: if (pcc_data_ref) pcc_data_put(pcc_subspace_id); per_cpu(cpu_pcc_subspace_idx, pr->id) = -1;
out_buf_free: if (cpc_present) pr_err("CPU%d: failed to initialize _CPC: %d\n", pr->id, ret); kfree(output.pointer); return ret;}EXPORT_SYMBOL_GPL(acpi_cppc_processor_probe);
/** * acpi_cppc_processor_exit - Cleanup CPC structs. * @pr: Ptr to acpi_processor containing this CPU's logical ID. * * Return: Void */void acpi_cppc_processor_exit(struct acpi_processor *pr){ struct cpc_desc *cpc_ptr; int pcc_ss_id;
cpc_ptr = per_cpu(cpc_desc_ptr, pr->id); if (!cpc_ptr) { per_cpu(cpu_pcc_subspace_idx, pr->id) = -1; return; }
pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, pr->id); cpc_set_desc(pr->id, NULL); kobject_del(&cpc_ptr->kobj); cpc_unregister_non_mmio_desc(cpc_ptr); cpc_unregister_sysmem_desc(cpc_ptr);
pcc_data_put(pcc_ss_id); per_cpu(cpu_pcc_subspace_idx, pr->id) = -1;
kobject_put(&cpc_ptr->kobj);}EXPORT_SYMBOL_GPL(acpi_cppc_processor_exit);
/** * cpc_read_ffh() - Read FFH register * @cpunum: CPU number to read * @reg: cppc register information * @val: place holder for return value * * Read bit_width bits from a specified address and bit_offset * * Return: 0 for success and error code */int __weak cpc_read_ffh(int cpunum, struct cpc_reg *reg, u64 *val){ return -ENOTSUPP;}
/** * cpc_read_ffh_fb_ctrs() - Read FFH feedback counters together * @cpunum: Target CPU * @reg1: first CPPC register information * @val1: place holder for first return value * @reg2: second CPPC register information * @val2: place holder for second return value * * Return: 0 on success, error code otherwise */int __weak cpc_read_ffh_fb_ctrs(int cpunum, struct cpc_reg *reg1, u64 *val1, struct cpc_reg *reg2, u64 *val2){ return -EOPNOTSUPP;}
/** * cpc_write_ffh() - Write FFH register * @cpunum: CPU number to write * @reg: cppc register information * @val: value to write * * Write value of bit_width bits to a specified address and bit_offset * * Return: 0 for success and error code */int __weak cpc_write_ffh(int cpunum, struct cpc_reg *reg, u64 val){ return -ENOTSUPP;}
/* * Since cpc_read and cpc_write are called while holding pcc_lock, it should be * as fast as possible. We have already mapped the PCC subspace during init, so * we can directly write to it. */
static int cpc_read(int cpu, struct cpc_register_resource *reg_res, u64 *val){ void __iomem *vaddr = NULL; unsigned long flags; u8 buf[sizeof(*val)]; unsigned int i; int size; int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu); struct cpc_reg *reg = ®_res->cpc_entry.reg;
if (!cpc_is_readable(reg_res)) return -EOPNOTSUPP;
if (reg_res->type == ACPI_TYPE_INTEGER) { *val = reg_res->cpc_entry.int_value; return 0; }
*val = 0; if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) return cpc_read_ffh(cpu, reg, val);
size = GET_BIT_WIDTH(reg);
if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_IO) { u32 val_u32; acpi_status status;
if (!IS_ENABLED(CONFIG_HAS_IOPORT)) return -EOPNOTSUPP;
status = acpi_os_read_port((acpi_io_address)reg->address, &val_u32, size); if (ACPI_FAILURE(status)) { pr_debug("Error: Failed to read SystemIO port %llx\n", reg->address); return -EFAULT; }
*val = MASK_VAL_READ(reg, val_u32); return 0; } else if (reg->space_id == ACPI_ADR_SPACE_PLATFORM_COMM) { if (pcc_ss_id < 0 || !pcc_data[pcc_ss_id]) return -ENODEV;
/* * For registers in PCC space, the register size is determined * by the bit width field; the access size is used to indicate * the PCC subspace id. */ vaddr = GET_PCC_VADDR(reg->address, pcc_ss_id); size = reg->bit_width / 8; if (!size || size > sizeof(buf) || reg->bit_width % 8) return -EFAULT;
raw_spin_lock_irqsave(&pcc_data[pcc_ss_id]->payload_lock, flags); memcpy_fromio(buf, vaddr, size); raw_spin_unlock_irqrestore(&pcc_data[pcc_ss_id]->payload_lock, flags);
*val = 0; for (i = 0; i < size; i++) *val |= (u64)buf[i] << (i * 8); return 0; } else if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) vaddr = reg_res->sys_mem_vaddr; else return acpi_os_read_memory((acpi_physical_address)reg->address, val, size);
switch (size) { case 8: *val = readb_relaxed(vaddr); break; case 16: *val = readw_relaxed(vaddr); break; case 32: *val = readl_relaxed(vaddr); break; case 64: *val = readq_relaxed(vaddr); break; default: pr_debug("Error: Cannot read %u bit width from system memory: 0x%llx\n", size, reg->address); return -EFAULT; }
*val = MASK_VAL_READ(reg, *val);
return 0;}
static int cpc_write(int cpu, struct cpc_register_resource *reg_res, u64 val){ int ret_val = 0; int size; u64 prev_val; void __iomem *vaddr = NULL; int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu); struct cpc_reg *reg; struct cpc_desc *cpc_desc; unsigned long flags; u8 buf[sizeof(val)]; unsigned int i; bool locked = false;
if (!cpc_is_writable(reg_res)) return -EOPNOTSUPP;
reg = ®_res->cpc_entry.reg; if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) return cpc_write_ffh(cpu, reg, val);
size = GET_BIT_WIDTH(reg);
if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_IO) { acpi_status status;
if (!IS_ENABLED(CONFIG_HAS_IOPORT)) return -EOPNOTSUPP;
status = acpi_os_write_port((acpi_io_address)reg->address, (u32)val, size); if (ACPI_FAILURE(status)) { pr_debug("Error: Failed to write SystemIO port %llx\n", reg->address); return -EFAULT; }
return 0; } else if (reg->space_id == ACPI_ADR_SPACE_PLATFORM_COMM) { if (pcc_ss_id < 0 || !pcc_data[pcc_ss_id]) return -ENODEV;
/* * For registers in PCC space, the register size is determined * by the bit width field; the access size is used to indicate * the PCC subspace id. */ vaddr = GET_PCC_VADDR(reg->address, pcc_ss_id); size = reg->bit_width / 8; if (!size || size > sizeof(buf) || reg->bit_width % 8) return -EFAULT;
for (i = 0; i < size; i++) buf[i] = val >> (i * 8);
raw_spin_lock_irqsave(&pcc_data[pcc_ss_id]->payload_lock, flags); memcpy_toio(vaddr, buf, size); /* Publish every payload byte before another CPU can ring the doorbell. */ wmb(); raw_spin_unlock_irqrestore(&pcc_data[pcc_ss_id]->payload_lock, flags); return 0; } else if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) vaddr = reg_res->sys_mem_vaddr; else return acpi_os_write_memory((acpi_physical_address)reg->address, val, size);
/* Partial fields and local overlaps use the descriptor lock. */ locked = reg_res->cpc_entry.use_rmw_lock; if (locked) { cpc_desc = per_cpu(cpc_desc_ptr, cpu); if (!cpc_desc) { pr_debug("No CPC descriptor for CPU:%d\n", cpu); return -ENODEV; } raw_spin_lock_irqsave(&cpc_desc->rmw_lock, flags); }
if (reg->bit_offset || reg->bit_width != size) { /* * MASK_VAL_WRITE() discards the field's old bits, so undefined * readback from a write-only field is not propagated. */ switch (size) { case 8: prev_val = readb_relaxed(vaddr); break; case 16: prev_val = readw_relaxed(vaddr); break; case 32: prev_val = readl_relaxed(vaddr); break; case 64: prev_val = readq_relaxed(vaddr); break; default: if (locked) raw_spin_unlock_irqrestore(&cpc_desc->rmw_lock, flags); return -EFAULT; } val = MASK_VAL_WRITE(reg, prev_val, val); }
switch (size) { case 8: writeb_relaxed(val, vaddr); break; case 16: writew_relaxed(val, vaddr); break; case 32: writel_relaxed(val, vaddr); break; case 64: writeq_relaxed(val, vaddr); break; default: pr_debug("Error: Cannot write %u bit width to system memory: 0x%llx\n", size, reg->address); ret_val = -EFAULT; break; }
if (locked) { if (!ret_val) mmiowb_set_pending(); raw_spin_unlock_irqrestore(&cpc_desc->rmw_lock, flags); }
return ret_val;}
static int cppc_get_reg_val_in_pcc(int cpu, struct cpc_register_resource *reg, u64 *val){ int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu); struct cppc_pcc_data *pcc_ss_data = NULL; int ret;
if (pcc_ss_id < 0) { pr_debug("Invalid pcc_ss_id\n"); return -ENODEV; }
pcc_ss_data = pcc_data[pcc_ss_id];
down_write(&pcc_ss_data->pcc_lock);
if (send_pcc_cmd(pcc_ss_id, CMD_READ) >= 0) ret = cpc_read(cpu, reg, val); else ret = -EIO;
up_write(&pcc_ss_data->pcc_lock);
return ret;}
static int cppc_get_reg_val(int cpu, enum cppc_regs reg_idx, u64 *val){ struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpu); struct cpc_register_resource *reg;
if (val == NULL) return -EINVAL;
if (!cpc_desc) { pr_debug("No CPC descriptor for CPU:%d\n", cpu); return -ENODEV; } if (cpc_reg_is_write_only(cpc_desc, reg_idx)) return -EOPNOTSUPP;
reg = &cpc_desc->cpc_regs[reg_idx];
/* * Desired and Performance Limited may be disabled despite not being * generally optional. */ if ((reg->type == ACPI_TYPE_INTEGER && (IS_OPTIONAL_CPC_REG(reg_idx) || reg_idx == DESIRED_PERF || reg_idx == PERF_LIMITED) && !reg->cpc_entry.int_value) || (reg->type != ACPI_TYPE_INTEGER && IS_NULL_REG(®->cpc_entry.reg))) { pr_debug("CPC register is not supported\n"); return -EOPNOTSUPP; } if (!cpc_is_readable(reg)) return -EOPNOTSUPP;
if (CPC_IN_PCC(reg)) return cppc_get_reg_val_in_pcc(cpu, reg, val);
return cpc_read(cpu, reg, val);}
static int cppc_set_reg_val_in_pcc(int cpu, struct cpc_register_resource *reg, u64 val){ int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu); struct cppc_pcc_data *pcc_ss_data; int ret;
if (pcc_ss_id < 0) { pr_debug("Invalid pcc_ss_id\n"); return -ENODEV; } pcc_ss_data = pcc_data[pcc_ss_id]; if (!pcc_ss_data) return -ENODEV;
down_write(&pcc_ss_data->pcc_lock);
ret = check_pcc_chan(pcc_ss_id, false); if (ret) goto out;
ret = cpc_write(cpu, reg, val); if (ret) goto out;
/* after writing CPC, transfer the ownership of PCC to platform */ ret = send_pcc_cmd(pcc_ss_id, CMD_WRITE);
out: if (ret) cppc_abort_pending_pcc_write(pcc_ss_id, pcc_ss_data, ret); up_write(&pcc_ss_data->pcc_lock);
return ret;}
static int cppc_set_reg_val(int cpu, enum cppc_regs reg_idx, u64 val){ struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpu); struct cpc_register_resource *reg;
if (!cpc_desc) { pr_debug("No CPC descriptor for CPU:%d\n", cpu); return -ENODEV; }
reg = &cpc_desc->cpc_regs[reg_idx];
/* Integer 1 describes autonomous selection that is always enabled. */ if (reg_idx == AUTO_SEL_ENABLE && reg->type == ACPI_TYPE_INTEGER && reg->cpc_entry.int_value == 1) return val == 1 ? 0 : -EOPNOTSUPP;
/* if a register is writeable, it must be a buffer and not null */ if (!cpc_is_writable(reg)) { pr_debug("CPC register is not supported\n"); return -EOPNOTSUPP; }
if (CPC_IN_PCC(reg)) return cppc_set_reg_val_in_pcc(cpu, reg, val);
return cpc_write(cpu, reg, val);}
/** * cppc_get_desired_perf - Get the desired performance register value. * @cpunum: CPU from which to get desired performance. * @desired_perf: Return address. * * Return: 0 for success, -EOPNOTSUPP for _CPC revision 4 or later, and a * negative errno otherwise. */int cppc_get_desired_perf(int cpunum, u64 *desired_perf){ return cppc_get_reg_val(cpunum, DESIRED_PERF, desired_perf);}EXPORT_SYMBOL_GPL(cppc_get_desired_perf);
/** * cppc_get_nominal_perf - Get the nominal performance register value. * @cpunum: CPU from which to get nominal performance. * @nominal_perf: Return address. * * Return: 0 for success, -EIO otherwise. */int cppc_get_nominal_perf(int cpunum, u64 *nominal_perf){ return cppc_get_reg_val(cpunum, NOMINAL_PERF, nominal_perf);}
/** * cppc_get_highest_perf - Get the highest performance register value. * @cpunum: CPU from which to get highest performance. * @highest_perf: Return address. * * Return: 0 for success, -EIO otherwise. */int cppc_get_highest_perf(int cpunum, u64 *highest_perf){ return cppc_get_reg_val(cpunum, HIGHEST_PERF, highest_perf);}EXPORT_SYMBOL_GPL(cppc_get_highest_perf);
/** * cppc_get_epp_perf - Get the epp register value. * @cpunum: CPU from which to get epp preference value. * @epp_perf: Return address. * * Return: 0 for success, -EIO otherwise. */int cppc_get_epp_perf(int cpunum, u64 *epp_perf){ return cppc_get_reg_val(cpunum, ENERGY_PERF, epp_perf);}EXPORT_SYMBOL_GPL(cppc_get_epp_perf);
/** * cppc_get_perf_caps - Get a CPU's performance capabilities. * @cpunum: CPU from which to get capabilities info. * @perf_caps: ptr to cppc_perf_caps. See cppc_acpi.h * * Return: 0 for success with perf_caps populated else -ERRNO. */int cppc_get_perf_caps(int cpunum, struct cppc_perf_caps *perf_caps){ struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpunum); struct cpc_register_resource *highest_reg, *lowest_reg, *lowest_non_linear_reg, *nominal_reg, *reference_reg, *guaranteed_reg, *low_freq_reg = NULL, *nom_freq_reg = NULL; u64 high, low, guaranteed = 0, nom, ref, min_nonlinear, low_f = 0, nom_f = 0; int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpunum); struct cppc_pcc_data *pcc_ss_data = NULL; int ret = 0, regs_in_pcc = 0;
if (!cpc_desc) { pr_debug("No CPC descriptor for CPU:%d\n", cpunum); return -ENODEV; }
highest_reg = &cpc_desc->cpc_regs[HIGHEST_PERF]; lowest_reg = &cpc_desc->cpc_regs[LOWEST_PERF]; lowest_non_linear_reg = &cpc_desc->cpc_regs[LOW_NON_LINEAR_PERF]; nominal_reg = &cpc_desc->cpc_regs[NOMINAL_PERF]; reference_reg = &cpc_desc->cpc_regs[REFERENCE_PERF]; low_freq_reg = &cpc_desc->cpc_regs[LOWEST_FREQ]; nom_freq_reg = &cpc_desc->cpc_regs[NOMINAL_FREQ]; guaranteed_reg = &cpc_desc->cpc_regs[GUARANTEED_PERF];
/* Are any of the regs PCC ?*/ if (CPC_IN_PCC(highest_reg) || CPC_IN_PCC(lowest_reg) || CPC_IN_PCC(lowest_non_linear_reg) || CPC_IN_PCC(nominal_reg) || (CPC_SUPPORTED(reference_reg) && CPC_IN_PCC(reference_reg)) || CPC_IN_PCC(low_freq_reg) || CPC_IN_PCC(nom_freq_reg) || CPC_IN_PCC(guaranteed_reg)) { if (pcc_ss_id < 0) { pr_debug("Invalid pcc_ss_id\n"); return -ENODEV; } pcc_ss_data = pcc_data[pcc_ss_id]; regs_in_pcc = 1; down_write(&pcc_ss_data->pcc_lock); /* Ring doorbell once to update PCC subspace */ if (send_pcc_cmd(pcc_ss_id, CMD_READ) < 0) { ret = -EIO; goto out_err; } }
ret = cpc_read(cpunum, highest_reg, &high); if (ret) goto out_err; perf_caps->highest_perf = high;
ret = cpc_read(cpunum, lowest_reg, &low); if (ret) goto out_err; perf_caps->lowest_perf = low;
ret = cpc_read(cpunum, nominal_reg, &nom); if (ret) goto out_err; perf_caps->nominal_perf = nom;
/* * If reference perf register is not supported then we should * use the nominal perf value */ if (CPC_SUPPORTED(reference_reg)) { ret = cpc_read(cpunum, reference_reg, &ref); if (ret) goto out_err; } else { ref = nom; } perf_caps->reference_perf = ref;
if (guaranteed_reg->type != ACPI_TYPE_BUFFER || IS_NULL_REG(&guaranteed_reg->cpc_entry.reg)) { perf_caps->guaranteed_perf = 0; } else { ret = cpc_read(cpunum, guaranteed_reg, &guaranteed); if (ret) goto out_err; perf_caps->guaranteed_perf = guaranteed; }
ret = cpc_read(cpunum, lowest_non_linear_reg, &min_nonlinear); if (ret) goto out_err; perf_caps->lowest_nonlinear_perf = min_nonlinear;
if (!high || !low || !nom || !ref || !min_nonlinear || high > U32_MAX || low > U32_MAX || guaranteed > U32_MAX || nom > U32_MAX || ref > U32_MAX || min_nonlinear > U32_MAX || high < nom || nom < min_nonlinear || min_nonlinear < low || (CPC_SUPPORTED(guaranteed_reg) && (guaranteed < low || guaranteed > nom))) { ret = -EFAULT; goto out_err; }
/* Read optional lowest and nominal frequencies if present */ if (CPC_SUPPORTED(low_freq_reg)) { ret = cpc_read(cpunum, low_freq_reg, &low_f); if (ret) goto out_err; }
if (CPC_SUPPORTED(nom_freq_reg)) { ret = cpc_read(cpunum, nom_freq_reg, &nom_f); if (ret) goto out_err; } /* Require ordered anchors and a nonzero slope when frequencies differ. */ if (low_f > U32_MAX || nom_f > U32_MAX || (low_f && nom_f && (nom_f < low_f || nom < low || (nom_f != low_f && nom == low)))) { ret = -EFAULT; goto out_err; }
perf_caps->lowest_freq = low_f; perf_caps->nominal_freq = nom_f;
out_err: if (regs_in_pcc) up_write(&pcc_ss_data->pcc_lock); return ret;}EXPORT_SYMBOL_GPL(cppc_get_perf_caps);
/** * cppc_perf_ctrs_in_pcc_cpu - Check if any perf counters of a CPU are in PCC. * @cpu: CPU on which to check perf counters. * * Return: true if any of the counters are in PCC regions, false otherwise */bool cppc_perf_ctrs_in_pcc_cpu(unsigned int cpu){ struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpu);
if (!cpc_desc) return false;
return CPC_IN_PCC(&cpc_desc->cpc_regs[DELIVERED_CTR]) || CPC_IN_PCC(&cpc_desc->cpc_regs[REFERENCE_CTR]) || CPC_IN_PCC(&cpc_desc->cpc_regs[CTR_WRAP_TIME]);}EXPORT_SYMBOL_GPL(cppc_perf_ctrs_in_pcc_cpu);
static int cppc_read_fb_ctrs(int cpunum, struct cpc_register_resource *delivered_reg, struct cpc_register_resource *reference_reg, u64 *delivered, u64 *reference){ int ret;
/* * For FFH feedback counters, try a paired read first to reduce * sampling skew between delivered and reference counters. Fall * back to the existing per-register reads if unsupported. */ if (CPC_IN_FFH(delivered_reg) && CPC_IN_FFH(reference_reg)) { ret = cpc_read_ffh_fb_ctrs(cpunum, &delivered_reg->cpc_entry.reg, delivered, &reference_reg->cpc_entry.reg, reference); if (ret != -EOPNOTSUPP) return ret; }
ret = cpc_read(cpunum, delivered_reg, delivered); if (ret) return ret;
return cpc_read(cpunum, reference_reg, reference);}
/** * cppc_perf_ctrs_in_pcc - Check if any perf counters are in a PCC region. * * CPPC has flexibility about how CPU performance counters are accessed. * One of the choices is PCC regions, which can have a high access latency. This * routine allows callers of cppc_get_perf_ctrs() to know this ahead of time. * * Return: true if any of the counters are in PCC regions, false otherwise */bool cppc_perf_ctrs_in_pcc(void){ int cpu;
for_each_online_cpu(cpu) { if (cppc_perf_ctrs_in_pcc_cpu(cpu)) return true; }
return false;}EXPORT_SYMBOL_GPL(cppc_perf_ctrs_in_pcc);
/** * cppc_get_perf_ctrs - Read a CPU's performance feedback counters. * @cpunum: CPU from which to read counters. * @perf_fb_ctrs: ptr to cppc_perf_fb_ctrs. See cppc_acpi.h * * Return: 0 for success with perf_fb_ctrs populated else -ERRNO. */int cppc_get_perf_ctrs(int cpunum, struct cppc_perf_fb_ctrs *perf_fb_ctrs){ struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpunum); struct cpc_register_resource *delivered_reg, *reference_reg, *ctr_wrap_reg; int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpunum); struct cppc_pcc_data *pcc_ss_data = NULL; u64 delivered, reference, ctr_wrap_time; int ret = 0, regs_in_pcc = 0;
if (!cpc_desc) { pr_debug("No CPC descriptor for CPU:%d\n", cpunum); return -ENODEV; }
delivered_reg = &cpc_desc->cpc_regs[DELIVERED_CTR]; reference_reg = &cpc_desc->cpc_regs[REFERENCE_CTR]; ctr_wrap_reg = &cpc_desc->cpc_regs[CTR_WRAP_TIME];
/* Are any of the regs PCC ?*/ if (CPC_IN_PCC(delivered_reg) || CPC_IN_PCC(reference_reg) || CPC_IN_PCC(ctr_wrap_reg)) { if (pcc_ss_id < 0) { pr_debug("Invalid pcc_ss_id\n"); return -ENODEV; } pcc_ss_data = pcc_data[pcc_ss_id]; down_write(&pcc_ss_data->pcc_lock); regs_in_pcc = 1; /* Ring doorbell once to update PCC subspace */ if (send_pcc_cmd(pcc_ss_id, CMD_READ) < 0) { ret = -EIO; goto out_err; } }
ret = cppc_read_fb_ctrs(cpunum, delivered_reg, reference_reg, &delivered, &reference); if (ret) goto out_err;
/* * Per spec, if ctr_wrap_time optional register is unsupported, then the * performance counters are assumed to never wrap during the lifetime of * platform */ ctr_wrap_time = (u64)(~((u64)0)); if (CPC_SUPPORTED(ctr_wrap_reg)) { ret = cpc_read(cpunum, ctr_wrap_reg, &ctr_wrap_time); if (ret) goto out_err; }
if (!delivered || !reference) { ret = -EFAULT; goto out_err; }
perf_fb_ctrs->delivered = delivered; perf_fb_ctrs->reference = reference; perf_fb_ctrs->wraparound_time = ctr_wrap_time;out_err: if (regs_in_pcc) up_write(&pcc_ss_data->pcc_lock); return ret;}EXPORT_SYMBOL_GPL(cppc_get_perf_ctrs);
/* * Set Energy Performance Preference Register value through * Performance Controls Interface */int cppc_set_epp_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls, bool enable){ int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu); struct cpc_register_resource *epp_set_reg; struct cpc_register_resource *auto_sel_reg; struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpu); struct cppc_pcc_data *pcc_ss_data = NULL; bool auto_sel_pcc; bool auto_sel_non_pcc; bool epp_pcc; bool epp_non_pcc; int ret;
if (!cpc_desc) { pr_debug("No CPC descriptor for CPU:%d\n", cpu); return -ENODEV; }
auto_sel_reg = &cpc_desc->cpc_regs[AUTO_SEL_ENABLE]; epp_set_reg = &cpc_desc->cpc_regs[ENERGY_PERF]; if (!enable && auto_sel_reg->type == ACPI_TYPE_INTEGER && auto_sel_reg->cpc_entry.int_value == 1) return -EOPNOTSUPP;
auto_sel_pcc = cpc_is_writable(auto_sel_reg) && CPC_IN_PCC(auto_sel_reg); epp_pcc = cpc_is_writable(epp_set_reg) && CPC_IN_PCC(epp_set_reg);
auto_sel_non_pcc = cpc_is_writable(auto_sel_reg) && !auto_sel_pcc; epp_non_pcc = cpc_is_writable(epp_set_reg) && !epp_pcc;
/* Complete fallible non-PCC writes before staging PCC data. */ if (auto_sel_non_pcc) { ret = cpc_write(cpu, auto_sel_reg, enable); if (ret) return ret; } if (epp_non_pcc) { ret = cpc_write(cpu, epp_set_reg, perf_ctrls->energy_perf); if (ret) return ret; }
if (epp_pcc || auto_sel_pcc) { if (pcc_ss_id < 0) { pr_debug("Invalid pcc_ss_id for CPU:%d\n", cpu); return -ENODEV; }
pcc_ss_data = pcc_data[pcc_ss_id]; if (!pcc_ss_data) return -ENODEV;
down_write(&pcc_ss_data->pcc_lock);
ret = check_pcc_chan(pcc_ss_id, false); if (ret) goto out_unlock;
if (auto_sel_pcc) { ret = cpc_write(cpu, auto_sel_reg, enable); if (ret) goto out_unlock; }
if (epp_pcc) { ret = cpc_write(cpu, epp_set_reg, perf_ctrls->energy_perf); if (ret) goto out_unlock; }
/* after writing CPC, transfer the ownership of PCC to platform */ ret = send_pcc_cmd(pcc_ss_id, CMD_WRITE);
out_unlock: if (ret) cppc_abort_pending_pcc_write(pcc_ss_id, pcc_ss_data, ret); up_write(&pcc_ss_data->pcc_lock); } else if (epp_non_pcc || auto_sel_non_pcc) { ret = 0; } else { ret = -EOPNOTSUPP; pr_debug("No writable EPP controls for CPU:%d\n", cpu); }
return ret;}EXPORT_SYMBOL_GPL(cppc_set_epp_perf);
/** * cppc_set_epp() - Write the EPP register. * @cpu: CPU on which to write register. * @epp_val: Value to write to the EPP register. */int cppc_set_epp(int cpu, u64 epp_val){ if (epp_val > CPPC_EPP_ENERGY_EFFICIENCY_PREF) return -EINVAL;
return cppc_set_reg_val(cpu, ENERGY_PERF, epp_val);}EXPORT_SYMBOL_GPL(cppc_set_epp);
/** * cppc_get_auto_act_window() - Read autonomous activity window register. * @cpu: CPU from which to read register. * @auto_act_window: Return address. * * According to ACPI 6.5, s8.4.6.1.6, the value read from the autonomous * activity window register consists of two parts: a 7 bits value indicate * significand and a 3 bits value indicate exponent. */int cppc_get_auto_act_window(int cpu, u64 *auto_act_window){ unsigned int exp; u64 val, sig; int ret;
if (auto_act_window == NULL) return -EINVAL;
ret = cppc_get_reg_val(cpu, AUTO_ACT_WINDOW, &val); if (ret) return ret;
sig = val & CPPC_AUTO_ACT_WINDOW_MAX_SIG; exp = (val >> CPPC_AUTO_ACT_WINDOW_SIG_BIT_SIZE) & CPPC_AUTO_ACT_WINDOW_MAX_EXP; *auto_act_window = sig * int_pow(10, exp);
return 0;}EXPORT_SYMBOL_GPL(cppc_get_auto_act_window);
/** * cppc_set_auto_act_window() - Write autonomous activity window register. * @cpu: CPU on which to write register. * @auto_act_window: usec value to write to the autonomous activity window register. * * According to ACPI 6.5, s8.4.6.1.6, the value to write to the autonomous * activity window register consists of two parts: a 7 bits value indicate * significand and a 3 bits value indicate exponent. */int cppc_set_auto_act_window(int cpu, u64 auto_act_window){ /* The max value to store is 1270000000 */ u64 max_val = CPPC_AUTO_ACT_WINDOW_MAX_SIG * int_pow(10, CPPC_AUTO_ACT_WINDOW_MAX_EXP); int exp = 0; u64 val;
if (auto_act_window > max_val) return -EINVAL;
/* * The max significand is 127, when auto_act_window is larger than * 129, discard the precision of the last digit and increase the * exponent by 1. */ while (auto_act_window > CPPC_AUTO_ACT_WINDOW_SIG_CARRY_THRESH) { auto_act_window /= 10; exp += 1; }
/* For 128 and 129, cut it to 127. */ if (auto_act_window > CPPC_AUTO_ACT_WINDOW_MAX_SIG) auto_act_window = CPPC_AUTO_ACT_WINDOW_MAX_SIG;
val = (exp << CPPC_AUTO_ACT_WINDOW_SIG_BIT_SIZE) + auto_act_window;
return cppc_set_reg_val(cpu, AUTO_ACT_WINDOW, val);}EXPORT_SYMBOL_GPL(cppc_set_auto_act_window);
/** * cppc_get_auto_sel() - Read autonomous selection register. * @cpu: CPU from which to read register. * @enable: Return address. */int cppc_get_auto_sel(int cpu, bool *enable){ u64 auto_sel; int ret;
if (enable == NULL) return -EINVAL;
ret = cppc_get_reg_val(cpu, AUTO_SEL_ENABLE, &auto_sel); if (ret) return ret;
*enable = (bool)auto_sel;
return 0;}EXPORT_SYMBOL_GPL(cppc_get_auto_sel);
/** * cppc_auto_sel_is_immutable - Check for always-enabled autonomous selection. * @cpu: CPU whose _CPC descriptor to check. * * Context: Process context. * Return: true for Integer 1, false for a register or an absent descriptor. */bool cppc_auto_sel_is_immutable(int cpu){ struct cpc_desc *cpc_desc; struct cpc_register_resource *reg;
guard(mutex)(&cpc_desc_lock); cpc_desc = per_cpu(cpc_desc_ptr, cpu); if (!cpc_desc) return false;
reg = &cpc_desc->cpc_regs[AUTO_SEL_ENABLE]; return reg->type == ACPI_TYPE_INTEGER && reg->cpc_entry.int_value == 1;}EXPORT_SYMBOL_GPL(cppc_auto_sel_is_immutable);
/** * cppc_set_auto_sel - Write autonomous selection register. * @cpu : CPU to which to write register. * @enable : the desired value of autonomous selection resiter to be updated. */int cppc_set_auto_sel(int cpu, bool enable){ return cppc_set_reg_val(cpu, AUTO_SEL_ENABLE, enable);}EXPORT_SYMBOL_GPL(cppc_set_auto_sel);
/** * cppc_set_enable - Set to enable CPPC on the processor by writing the * Continuous Performance Control package EnableRegister field. * @cpu: CPU for which to enable CPPC register. * @enable: 0 - disable, 1 - enable CPPC feature on the processor. * * Return: 0 for success, -ERRNO or -EIO otherwise. */int cppc_set_enable(int cpu, bool enable){ return cppc_set_reg_val(cpu, ENABLE, enable);}EXPORT_SYMBOL_GPL(cppc_set_enable);
/** * cppc_get_perf - Get a CPU's performance controls. * @cpu: CPU for which to get performance controls. * @perf_ctrls: ptr to cppc_perf_ctrls. See cppc_acpi.h * * Desired Performance is not read and is returned as 0. * * Return: 0 for success with perf_ctrls, -ERRNO otherwise. */int cppc_get_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls){ struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpu); struct cpc_register_resource *min_perf_reg, *max_perf_reg, *energy_perf_reg, *auto_sel_reg; u64 min = 0, max = 0, energy_perf = 0, auto_sel = 0; int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu); struct cppc_pcc_data *pcc_ss_data = NULL; int ret = 0, regs_in_pcc = 0;
if (!cpc_desc) { pr_debug("No CPC descriptor for CPU:%d\n", cpu); return -ENODEV; }
if (!perf_ctrls) { pr_debug("Invalid perf_ctrls pointer\n"); return -EINVAL; }
min_perf_reg = &cpc_desc->cpc_regs[MIN_PERF]; max_perf_reg = &cpc_desc->cpc_regs[MAX_PERF]; energy_perf_reg = &cpc_desc->cpc_regs[ENERGY_PERF]; auto_sel_reg = &cpc_desc->cpc_regs[AUTO_SEL_ENABLE]; perf_ctrls->min_perf_valid = false;
/* Are any of the regs PCC ?*/ if (CPC_IN_PCC(min_perf_reg) || CPC_IN_PCC(max_perf_reg) || CPC_IN_PCC(energy_perf_reg) || CPC_IN_PCC(auto_sel_reg)) { if (pcc_ss_id < 0) { pr_debug("Invalid pcc_ss_id for CPU:%d\n", cpu); return -ENODEV; } pcc_ss_data = pcc_data[pcc_ss_id]; regs_in_pcc = 1; down_write(&pcc_ss_data->pcc_lock); /* Ring doorbell once to update PCC subspace */ if (send_pcc_cmd(pcc_ss_id, CMD_READ) < 0) { ret = -EIO; goto out_err; } }
/* Read optional elements if present */ if (CPC_SUPPORTED(max_perf_reg)) { ret = cpc_read(cpu, max_perf_reg, &max); if (ret) goto out_err; if (max > U32_MAX) { ret = -EFAULT; goto out_err; } } perf_ctrls->max_perf = max;
if (CPC_SUPPORTED(min_perf_reg)) { ret = cpc_read(cpu, min_perf_reg, &min); if (ret) goto out_err; if (min > U32_MAX) { ret = -EFAULT; goto out_err; } perf_ctrls->min_perf_valid = true; } perf_ctrls->min_perf = min;
perf_ctrls->desired_perf = 0;
if (CPC_SUPPORTED(energy_perf_reg)) { ret = cpc_read(cpu, energy_perf_reg, &energy_perf); if (ret) goto out_err; } perf_ctrls->energy_perf = energy_perf;
if (CPC_SUPPORTED(auto_sel_reg)) { ret = cpc_read(cpu, auto_sel_reg, &auto_sel); if (ret) goto out_err; } perf_ctrls->auto_sel = (bool)auto_sel;
out_err: if (regs_in_pcc) up_write(&pcc_ss_data->pcc_lock); return ret;}EXPORT_SYMBOL_GPL(cppc_get_perf);
/** * cppc_set_perf - Set a CPU's performance controls. * @cpu: CPU for which to set performance controls. * @perf_ctrls: ptr to cppc_perf_ctrls. See cppc_acpi.h * * Return: 0 for success, -ERRNO otherwise. */int cppc_set_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls){ struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpu); struct cpc_register_resource *desired_reg, *min_perf_reg, *max_perf_reg; int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu); struct cppc_pcc_data *pcc_ss_data = NULL; bool desired_update, min_update, max_update; bool desired_pcc, min_pcc, max_pcc, pcc_update; bool pcc_layout, direct_layout, mixed_layout; int ret = 0;
if (!cpc_desc) { pr_debug("No CPC descriptor for CPU:%d\n", cpu); return -ENODEV; }
desired_reg = &cpc_desc->cpc_regs[DESIRED_PERF]; min_perf_reg = &cpc_desc->cpc_regs[MIN_PERF]; max_perf_reg = &cpc_desc->cpc_regs[MAX_PERF]; desired_update = cpc_is_writable(desired_reg); min_update = cpc_is_writable(min_perf_reg) && (perf_ctrls->min_perf || perf_ctrls->min_perf_valid); max_update = cpc_is_writable(max_perf_reg) && perf_ctrls->max_perf; desired_pcc = desired_update && CPC_IN_PCC(desired_reg); min_pcc = min_update && CPC_IN_PCC(min_perf_reg); max_pcc = max_update && CPC_IN_PCC(max_perf_reg); pcc_update = desired_pcc || min_pcc || max_pcc; pcc_layout = (cpc_is_writable(desired_reg) && CPC_IN_PCC(desired_reg)) || (cpc_is_writable(min_perf_reg) && CPC_IN_PCC(min_perf_reg)) || (cpc_is_writable(max_perf_reg) && CPC_IN_PCC(max_perf_reg)); direct_layout = (cpc_is_writable(desired_reg) && !CPC_IN_PCC(desired_reg)) || (cpc_is_writable(min_perf_reg) && !CPC_IN_PCC(min_perf_reg)) || (cpc_is_writable(max_perf_reg) && !CPC_IN_PCC(max_perf_reg)); mixed_layout = pcc_layout && direct_layout;
if (mixed_layout || pcc_update) { if (pcc_ss_id < 0) { pr_debug("Invalid pcc_ss_id\n"); return -ENODEV; } pcc_ss_data = pcc_data[pcc_ss_id]; if (!pcc_ss_data) return -ENODEV; }
/* * A mixed layout cannot batch fallible direct writes safely: another * CPU's staged PCC values may no longer match if a direct write fails. * Serialize the complete mixed transaction and drain an older batch * before changing a direct control. */ if (mixed_layout) { down_write(&pcc_ss_data->pcc_lock); if (pcc_ss_data->pending_pcc_write_cmd) { ret = send_pcc_cmd(pcc_ss_id, CMD_WRITE); if (ret) goto out_mixed_unlock; }
if (pcc_ss_data->platform_owns_pcc) { ret = check_pcc_chan(pcc_ss_id, false); if (ret) goto out_mixed_unlock; }
if (desired_update && !desired_pcc) { ret = cpc_write(cpu, desired_reg, perf_ctrls->desired_perf); if (ret) goto out_mixed_unlock; } if (min_update && !min_pcc) { ret = cpc_write(cpu, min_perf_reg, perf_ctrls->min_perf); if (ret) goto out_mixed_unlock; } if (max_update && !max_pcc) { ret = cpc_write(cpu, max_perf_reg, perf_ctrls->max_perf); if (ret) goto out_mixed_unlock; }
if (desired_pcc) { ret = cpc_write(cpu, desired_reg, perf_ctrls->desired_perf); if (ret) goto out_mixed_unlock; } if (min_pcc) { ret = cpc_write(cpu, min_perf_reg, perf_ctrls->min_perf); if (ret) goto out_mixed_unlock; } if (max_pcc) { ret = cpc_write(cpu, max_perf_reg, perf_ctrls->max_perf); if (ret) goto out_mixed_unlock; }
if (pcc_update) { WRITE_ONCE(pcc_ss_data->pending_pcc_write_cmd, true); cpc_desc->write_cmd_id = pcc_ss_data->pcc_write_cnt; cpc_desc->write_cmd_status = 0; ret = send_pcc_cmd(pcc_ss_id, CMD_WRITE); }
out_mixed_unlock: up_write(&pcc_ss_data->pcc_lock); return ret; }
/* A request without PCC updates has no payload to coordinate. */ if (!pcc_update) { if (desired_update) { ret = cpc_write(cpu, desired_reg, perf_ctrls->desired_perf); if (ret) return ret; } if (min_update) { ret = cpc_write(cpu, min_perf_reg, perf_ctrls->min_perf); if (ret) return ret; } if (max_update) ret = cpc_write(cpu, max_perf_reg, perf_ctrls->max_perf); return ret; }
down_read(&pcc_ss_data->pcc_lock); /* BEGIN Phase-I */ if (pcc_ss_data->platform_owns_pcc) { ret = check_pcc_chan(pcc_ss_id, false); if (ret) goto out_pcc_read_unlock; }
/* * This is Phase-I where we want to write to CPC registers * -> We want all CPUs to be able to execute this phase in parallel * * Since read_lock can be acquired by multiple CPUs simultaneously we * achieve that goal here. */ if (desired_pcc) { ret = cpc_write(cpu, desired_reg, perf_ctrls->desired_perf); if (ret) goto out_pcc_read_unlock; }
if (min_pcc) { ret = cpc_write(cpu, min_perf_reg, perf_ctrls->min_perf); if (ret) goto out_pcc_read_unlock; } if (max_pcc) { ret = cpc_write(cpu, max_perf_reg, perf_ctrls->max_perf); if (ret) goto out_pcc_read_unlock; }
/* Block a PCC read until the staged payload has been submitted. */ WRITE_ONCE(pcc_ss_data->pending_pcc_write_cmd, true); cpc_desc->write_cmd_id = pcc_ss_data->pcc_write_cnt; cpc_desc->write_cmd_status = 0; up_read(&pcc_ss_data->pcc_lock); /* END Phase-I */ /* * This is Phase-II where we transfer the ownership of PCC to Platform * * Short Summary: Basically if we think of a group of cppc_set_perf * requests that happened in short overlapping interval. The last CPU to * come out of Phase-I will enter Phase-II and ring the doorbell. * * We have the following requirements for Phase-II: * 1. We want to execute Phase-II only when there are no CPUs * currently executing in Phase-I * 2. Once we start Phase-II we want to avoid all other CPUs from * entering Phase-I. * 3. We want only one CPU among all those who went through Phase-I * to run phase-II * * If write_trylock fails to get the lock and doesn't transfer the * PCC ownership to the platform, then one of the following will be TRUE * 1. There is at-least one CPU in Phase-I which will later execute * write_trylock, so the CPUs in Phase-I will be responsible for * executing the Phase-II. * 2. Some other CPU has beaten this CPU to successfully execute the * write_trylock and has already acquired the write_lock. We know for a * fact it (other CPU acquiring the write_lock) couldn't have happened * before this CPU's Phase-I as we held the read_lock. * 3. Some other CPU executing pcc CMD_READ has stolen the * down_write, in which case, send_pcc_cmd will check for pending * CMD_WRITE commands by checking the pending_pcc_write_cmd. * So this CPU can be certain that its request will be delivered * So in all cases, this CPU knows that its request will be delivered * by another CPU and can return * * After getting the down_write we still need to check for * pending_pcc_write_cmd to take care of the following scenario * The thread running this code could be scheduled out between * Phase-I and Phase-II. Before it is scheduled back on, another CPU * could have delivered the request to Platform by triggering the * doorbell and transferred the ownership of PCC to platform. So this * avoids triggering an unnecessary doorbell and more importantly before * triggering the doorbell it makes sure that the PCC channel ownership * is still with OSPM. * pending_pcc_write_cmd can also be cleared by a different CPU, if * there was a pcc CMD_READ waiting on down_write and it steals the lock * before the pcc CMD_WRITE is completed. send_pcc_cmd checks for this * case during a CMD_READ and if there are pending writes it delivers * the write command before servicing the read command */ if (down_write_trylock(&pcc_ss_data->pcc_lock)) {/* BEGIN Phase-II */ /* Update only if there are pending write commands */ if (pcc_ss_data->pending_pcc_write_cmd) send_pcc_cmd(pcc_ss_id, CMD_WRITE); up_write(&pcc_ss_data->pcc_lock); /* END Phase-II */ } else { /* Wait until pcc_write_cnt is updated by send_pcc_cmd */ wait_event(pcc_ss_data->pcc_write_wait_q, cpc_desc->write_cmd_id != pcc_ss_data->pcc_write_cnt); }
/* send_pcc_cmd updates the status in case of failure */ return cpc_desc->write_cmd_status;
out_pcc_read_unlock: up_read(&pcc_ss_data->pcc_lock); return ret;}EXPORT_SYMBOL_GPL(cppc_set_perf);
/** * cppc_get_perf_limited - Get the Performance Limited register value. * @cpu: CPU from which to get Performance Limited register. * @perf_limited: Pointer to store the Performance Limited value. * * The returned value contains sticky status bits indicating platform-imposed * performance limitations. * * Return: 0 for success, -EIO on failure, -EOPNOTSUPP if not supported. */int cppc_get_perf_limited(int cpu, u64 *perf_limited){ return cppc_get_reg_val(cpu, PERF_LIMITED, perf_limited);}EXPORT_SYMBOL_GPL(cppc_get_perf_limited);
/** * cppc_set_perf_limited() - Clear bits in the Performance Limited register. * @cpu: CPU on which to write register. * @bits_to_clear: Zero for no-op or CPPC_PERF_LIMITED_MASK to clear both bits. * * The Performance Limited register contains two sticky bits set by platform: * - Bit 0 (Desired_Excursion): Set when delivered performance is constrained * below desired performance. Not used when Autonomous Selection is enabled. * - Bit 1 (Minimum_Excursion): Set when delivered performance is constrained * below minimum performance. * * These bits are sticky and remain set until OSPM explicitly clears them. * Selective clears are unsupported because they require an interlocked RMW. * * Return: 0 for success, -EINVAL for invalid bits, -EIO on register * access failure, -EOPNOTSUPP if not supported. */int cppc_set_perf_limited(int cpu, u64 bits_to_clear){ /* Only bits 0 and 1 are valid */ if (bits_to_clear & ~(u64)CPPC_PERF_LIMITED_MASK) return -EINVAL;
if (!bits_to_clear) return 0;
/* * Writing zero clears both bits without depending on how a platform * treats written ones. ACPI does not define the effect of writing one, * so a selective clear cannot be implemented without an interlocked RMW. */ if (bits_to_clear != CPPC_PERF_LIMITED_MASK) return -EOPNOTSUPP;
return cppc_set_reg_val(cpu, PERF_LIMITED, 0);}EXPORT_SYMBOL_GPL(cppc_set_perf_limited);
/** * cppc_get_transition_latency - returns frequency transition latency in ns * @cpu_num: CPU number for per_cpu(). * * ACPI CPPC does not explicitly specify how a platform can specify the * transition latency for performance change requests. The closest we have * is the timing information from the PCCT tables which provides the info * on the number and frequency of PCC commands the platform can handle. * * If desired_reg is in the SystemMemory or SystemIo ACPI address space, * then assume there is no latency. */int cppc_get_transition_latency(int cpu_num){ /* * Expected transition latency is based on the PCCT timing values * Below are definition from ACPI spec: * pcc_nominal- Expected latency to process a command, in microseconds * pcc_mpar - The maximum number of periodic requests that the subspace * channel can support, reported in commands per minute. 0 * indicates no limitation. * pcc_mrtt - The minimum amount of time that OSPM must wait after the * completion of a command before issuing the next command, * in microseconds. */ struct cpc_desc *cpc_desc; struct cpc_register_resource *desired_reg; int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu_num); struct cppc_pcc_data *pcc_ss_data; int latency_ns = 0;
cpc_desc = per_cpu(cpc_desc_ptr, cpu_num); if (!cpc_desc) return -ENODATA;
desired_reg = &cpc_desc->cpc_regs[DESIRED_PERF]; if (!cpc_is_writable(desired_reg)) return -ENODATA;
if (CPC_IN_SYSTEM_MEMORY(desired_reg) || CPC_IN_SYSTEM_IO(desired_reg)) return 0;
if (!CPC_IN_PCC(desired_reg) || pcc_ss_id < 0) return -ENODATA;
pcc_ss_data = pcc_data[pcc_ss_id]; if (pcc_ss_data->pcc_mpar) latency_ns = 60 * (1000 * 1000 * 1000 / pcc_ss_data->pcc_mpar);
latency_ns = max_t(int, latency_ns, pcc_ss_data->pcc_nominal * 1000); latency_ns = max_t(int, latency_ns, pcc_ss_data->pcc_mrtt * 1000);
return latency_ns;}EXPORT_SYMBOL_GPL(cppc_get_transition_latency);
/* Minimum struct length needed for the DMI processor entry we want */#define DMI_ENTRY_PROCESSOR_MIN_LENGTH 48
/* Offset in the DMI processor structure for the max frequency */#define DMI_PROCESSOR_MAX_SPEED 0x14
/* Callback function used to retrieve the max frequency from DMI */static void cppc_find_dmi_mhz(const struct dmi_header *dm, void *private){ const u8 *dmi_data = (const u8 *)dm; u16 *mhz = (u16 *)private;
if (dm->type == DMI_ENTRY_PROCESSOR && dm->length >= DMI_ENTRY_PROCESSOR_MIN_LENGTH) { u16 val = (u16)get_unaligned((const u16 *) (dmi_data + DMI_PROCESSOR_MAX_SPEED)); *mhz = umax(val, *mhz); }}
/* Look up the max frequency in DMI */u64 cppc_get_dmi_max_khz(void){ u16 mhz = 0;
dmi_walk(cppc_find_dmi_mhz, &mhz);
/* * Real stupid fallback value, just in case there is no * actual value set. */ mhz = mhz ? mhz : 1;
return KHZ_PER_MHZ * mhz;}EXPORT_SYMBOL_GPL(cppc_get_dmi_max_khz);
/* * If CPPC lowest_freq and nominal_freq registers are exposed then we can * use them to convert perf to freq and vice versa. The conversion is * extrapolated as an affine function passing by the 2 points: * - (Low perf, Low freq) * - (Nominal perf, Nominal freq) */unsigned int cppc_perf_to_khz(struct cppc_perf_caps *caps, unsigned int perf){ s64 retval, offset = 0; static u64 max_khz; u64 mul, div;
if (caps->lowest_freq && caps->nominal_freq) { /* Avoid special case when nominal_freq is equal to lowest_freq */ if (caps->lowest_freq == caps->nominal_freq) { mul = caps->nominal_freq; div = caps->nominal_perf; } else { mul = caps->nominal_freq - caps->lowest_freq; div = caps->nominal_perf - caps->lowest_perf; } mul *= KHZ_PER_MHZ; offset = caps->nominal_freq * KHZ_PER_MHZ - div64_u64(caps->nominal_perf * mul, div); } else { if (!max_khz) max_khz = cppc_get_dmi_max_khz(); mul = max_khz; div = caps->highest_perf; }
retval = offset + div64_u64(perf * mul, div); if (retval >= 0) return retval; return 0;}EXPORT_SYMBOL_GPL(cppc_perf_to_khz);
unsigned int cppc_khz_to_perf(struct cppc_perf_caps *caps, unsigned int freq){ s64 retval, offset = 0; static u64 max_khz; u64 mul, div;
if (caps->lowest_freq && caps->nominal_freq) { /* Avoid special case when nominal_freq is equal to lowest_freq */ if (caps->lowest_freq == caps->nominal_freq) { mul = caps->nominal_perf; div = caps->nominal_freq; } else { mul = caps->nominal_perf - caps->lowest_perf; div = caps->nominal_freq - caps->lowest_freq; } /* * We don't need to convert to kHz for computing offset and can * directly use nominal_freq and lowest_freq as the div64_u64 * will remove the frequency unit. */ offset = caps->nominal_perf - div64_u64(caps->nominal_freq * mul, div); /* But we need it for computing the perf level. */ div *= KHZ_PER_MHZ; } else { if (!max_khz) max_khz = cppc_get_dmi_max_khz(); mul = caps->highest_perf; div = max_khz; }
retval = offset + div64_u64(freq * mul, div); if (retval >= 0) return retval; return 0;}EXPORT_SYMBOL_GPL(cppc_khz_to_perf);