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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239// SPDX-License-Identifier: GPL-2.0-only/* * linux/arch/arm/kernel/devtree.c * * Copyright (C) 2009 Canonical Ltd. <jeremy.kerr@canonical.com> */
#include <linux/init.h>#include <linux/export.h>#include <linux/errno.h>#include <linux/types.h>#include <linux/memblock.h>#include <linux/of.h>#include <linux/of_fdt.h>#include <linux/of_irq.h>#include <linux/smp.h>
#include <asm/cputype.h>#include <asm/setup.h>#include <asm/page.h>#include <asm/prom.h>#include <asm/smp_plat.h>#include <asm/mach/arch.h>#include <asm/mach-types.h>
#ifdef CONFIG_SMPextern struct of_cpu_method __cpu_method_of_table[];
static const struct of_cpu_method __cpu_method_of_table_sentinel __used __section("__cpu_method_of_table_end");
static int __init set_smp_ops_by_method(struct device_node *node){ const char *method; struct of_cpu_method *m = __cpu_method_of_table;
if (of_property_read_string(node, "enable-method", &method)) return 0;
for (; m->method; m++) if (!strcmp(m->method, method)) { smp_set_ops(m->ops); return 1; }
return 0;}#elsestatic inline int set_smp_ops_by_method(struct device_node *node){ return 1;}#endif
/* * arm_dt_init_cpu_maps - Function retrieves cpu nodes from the device tree * and builds the cpu logical map array containing MPIDR values related to * logical cpus * * Updates the cpu possible mask with the number of parsed cpu nodes */void __init arm_dt_init_cpu_maps(void){ /* * Temp logical map is initialized with UINT_MAX values that are * considered invalid logical map entries since the logical map must * contain a list of MPIDR[23:0] values where MPIDR[31:24] must * read as 0. */ struct device_node *cpu, *cpus; int found_method = 0; u32 i, j, cpuidx = 1; u32 mpidr = is_smp() ? read_cpuid_mpidr() & MPIDR_HWID_BITMASK : 0;
u32 tmp_map[NR_CPUS] = { [0 ... NR_CPUS-1] = MPIDR_INVALID }; bool bootcpu_valid = false; cpus = of_find_node_by_path("/cpus");
if (!cpus) return;
for_each_of_cpu_node(cpu) { u32 hwid = of_get_cpu_hwid(cpu, 0);
pr_debug(" * %pOF...\n", cpu);
/* * Bits n:24 must be set to 0 in the DT since the reg property * defines the MPIDR[23:0]. */ if (hwid & ~MPIDR_HWID_BITMASK) { of_node_put(cpu); return; }
/* * Duplicate MPIDRs are a recipe for disaster. * Scan all initialized entries and check for * duplicates. If any is found just bail out. * temp values were initialized to UINT_MAX * to avoid matching valid MPIDR[23:0] values. */ for (j = 0; j < cpuidx; j++) if (WARN(tmp_map[j] == hwid, "Duplicate /cpu reg properties in the DT\n")) { of_node_put(cpu); return; }
/* * Build a stashed array of MPIDR values. Numbering scheme * requires that if detected the boot CPU must be assigned * logical id 0. Other CPUs get sequential indexes starting * from 1. If a CPU node with a reg property matching the * boot CPU MPIDR is detected, this is recorded so that the * logical map built from DT is validated and can be used * to override the map created in smp_setup_processor_id(). */ if (hwid == mpidr) { i = 0; bootcpu_valid = true; } else { i = cpuidx++; }
if (WARN(cpuidx > nr_cpu_ids, "DT /cpu %u nodes greater than " "max cores %u, capping them\n", cpuidx, nr_cpu_ids)) { cpuidx = nr_cpu_ids; of_node_put(cpu); break; }
tmp_map[i] = hwid;
if (!found_method) found_method = set_smp_ops_by_method(cpu); }
/* * Fallback to an enable-method in the cpus node if nothing found in * a cpu node. */ if (!found_method) set_smp_ops_by_method(cpus);
if (!bootcpu_valid) { pr_warn("DT missing boot CPU MPIDR[23:0], fall back to default cpu_logical_map\n"); return; }
/* * Since the boot CPU node contains proper data, and all nodes have * a reg property, the DT CPU list can be considered valid and the * logical map created in smp_setup_processor_id() can be overridden */ for (i = 0; i < cpuidx; i++) { set_cpu_possible(i, true); cpu_logical_map(i) = tmp_map[i]; pr_debug("cpu logical map 0x%x\n", cpu_logical_map(i)); }}
bool arch_match_cpu_phys_id(int cpu, u64 phys_id){ return phys_id == cpu_logical_map(cpu);}
static const void * __init arch_get_next_mach(const char *const **match){ static const struct machine_desc *mdesc = __arch_info_begin; const struct machine_desc *m = mdesc;
if (m >= __arch_info_end) return NULL;
mdesc++; *match = m->dt_compat; return m;}
/** * setup_machine_fdt - Machine setup when an dtb was passed to the kernel * @dt_virt: virtual address of dt blob * * If a dtb was passed to the kernel in r2, then use it to choose the * correct machine_desc and to setup the system. */const struct machine_desc * __init setup_machine_fdt(void *dt_virt){ const struct machine_desc *mdesc, *mdesc_best = NULL;
DT_MACHINE_START(GENERIC_DT, "Generic DT based system") .l2c_aux_val = 0x0, .l2c_aux_mask = ~0x0, MACHINE_END
mdesc_best = &__mach_desc_GENERIC_DT;
if (!dt_virt || !early_init_dt_verify(dt_virt, __pa(dt_virt))) return NULL;
mdesc = of_flat_dt_match_machine(mdesc_best, arch_get_next_mach);
if (!mdesc) { const char *prop; int size; unsigned long dt_root;
early_print("\nError: unrecognized/unsupported " "device tree compatible list:\n[ ");
dt_root = of_get_flat_dt_root(); prop = of_get_flat_dt_prop(dt_root, "compatible", &size); while (size > 0) { early_print("'%s' ", prop); size -= strlen(prop) + 1; prop += strlen(prop) + 1; } early_print("]\n\n");
dump_machine_table(); /* does not return */ }
/* We really don't want to do this, but sometimes firmware provides buggy data */ if (mdesc->dt_fixup) mdesc->dt_fixup();
early_init_dt_scan_nodes();
/* Change machine number to match the mdesc we're using */ __machine_arch_type = mdesc->nr;
return mdesc;}