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(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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#include <linux/slab.h>#include <linux/errno.h>
#include "tb.h"
#define CAP_OFFSET_MAX 0xff#define VSE_CAP_OFFSET_MAX 0xffff#define TMU_ACCESS_EN BIT(20)
static int tb_port_enable_tmu(struct tb_port *port, bool enable){ struct tb_switch *sw = port->sw; u32 value, offset; int ret;
/* * Legacy devices need to have TMU access enabled before port * space can be fully accessed. */ if (tb_switch_is_light_ridge(sw)) offset = 0x26; else if (tb_switch_is_eagle_ridge(sw)) offset = 0x2a; else return 0;
ret = tb_sw_read(sw, &value, TB_CFG_SWITCH, offset, 1); if (ret) return ret;
if (enable) value |= TMU_ACCESS_EN; else value &= ~TMU_ACCESS_EN;
return tb_sw_write(sw, &value, TB_CFG_SWITCH, offset, 1);}
static void tb_port_dummy_read(struct tb_port *port){ /* * When reading from next capability pointer location in port * config space the read data is not cleared on LR. To avoid * reading stale data on next read perform one dummy read after * port capabilities are walked. */ if (tb_switch_is_light_ridge(port->sw)) { u32 dummy;
tb_port_read(port, &dummy, TB_CFG_PORT, 0, 1); }}
/** * tb_port_next_cap() - Return next capability in the linked list * @port: Port to find the capability for * @offset: Previous capability offset (%0 for start) * * Finds dword offset of the next capability in port config space * capability list. When passed %0 in @offset parameter, first entry * will be returned, if it exists. * * Return: * * Double word offset of the first or next capability - On success. * * %0 - If no next capability is found. * * Negative errno - Another error occurred. */int tb_port_next_cap(struct tb_port *port, unsigned int offset){ struct tb_cap_any header; int ret;
if (!offset) return port->config.first_cap_offset;
ret = tb_port_read(port, &header, TB_CFG_PORT, offset, 1); if (ret) return ret;
return header.basic.next;}
static int __tb_port_find_cap(struct tb_port *port, enum tb_port_cap cap){ int offset = 0;
do { struct tb_cap_any header; int ret;
offset = tb_port_next_cap(port, offset); if (offset < 0) return offset;
ret = tb_port_read(port, &header, TB_CFG_PORT, offset, 1); if (ret) return ret;
if (header.basic.cap == cap) return offset; } while (offset > 0);
return -ENOENT;}
/** * tb_port_find_cap() - Find port capability * @port: Port to find the capability for * @cap: Capability to look * * Return: * * Offset to the start of capability - On success. * * %-ENOENT - If no such capability was found. * * Negative errno - Another error occurred. */int tb_port_find_cap(struct tb_port *port, enum tb_port_cap cap){ int ret;
ret = tb_port_enable_tmu(port, true); if (ret) return ret;
ret = __tb_port_find_cap(port, cap);
tb_port_dummy_read(port); tb_port_enable_tmu(port, false);
return ret;}
/** * tb_switch_next_cap() - Return next capability in the linked list * @sw: Switch to find the capability for * @offset: Previous capability offset (%0 for start) * * Finds dword offset of the next capability in port config space * capability list. When passed %0 in @offset parameter, first entry * will be returned, if it exists. * * Return: * * Double word offset of the first or next capability - On success. * * %0 - If no next capability is found. * * Negative errno - Another error occurred. */int tb_switch_next_cap(struct tb_switch *sw, unsigned int offset){ struct tb_cap_any header; int ret;
if (!offset) return sw->config.first_cap_offset;
ret = tb_sw_read(sw, &header, TB_CFG_SWITCH, offset, 2); if (ret) return ret;
switch (header.basic.cap) { case TB_SWITCH_CAP_TMU: ret = header.basic.next; break;
case TB_SWITCH_CAP_VSE: if (!header.extended_short.length) ret = header.extended_long.next; else ret = header.extended_short.next; break;
default: tb_sw_dbg(sw, "unknown capability %#x at %#x\n", header.basic.cap, offset); ret = -EINVAL; break; }
return ret >= VSE_CAP_OFFSET_MAX ? 0 : ret;}
/** * tb_switch_find_cap() - Find switch capability * @sw: Switch to find the capability for * @cap: Capability to look * * Return: * * Offset to the start of capability - On success. * * %-ENOENT - If no such capability was found. * * Negative errno - Another error occurred. */int tb_switch_find_cap(struct tb_switch *sw, enum tb_switch_cap cap){ int offset = 0;
do { struct tb_cap_any header; int ret;
offset = tb_switch_next_cap(sw, offset); if (offset < 0) return offset;
ret = tb_sw_read(sw, &header, TB_CFG_SWITCH, offset, 1); if (ret) return ret;
if (header.basic.cap == cap) return offset; } while (offset);
return -ENOENT;}
/** * tb_switch_find_vse_cap() - Find switch vendor specific capability * @sw: Switch to find the capability for * @vsec: Vendor specific capability to look * * This function enumerates vendor specific capabilities (VSEC) of a * switch and returns offset when capability matching @vsec is found. * * Return: * * Offset of capability - On success. * * %-ENOENT - If capability was not found. * * Negative errno - Another error occurred. */int tb_switch_find_vse_cap(struct tb_switch *sw, enum tb_switch_vse_cap vsec){ int offset = 0;
do { struct tb_cap_any header; int ret;
offset = tb_switch_next_cap(sw, offset); if (offset < 0) return offset;
ret = tb_sw_read(sw, &header, TB_CFG_SWITCH, offset, 1); if (ret) return ret;
if (header.extended_short.cap == TB_SWITCH_CAP_VSE && header.extended_short.vsec_id == vsec) return offset; } while (offset);
return -ENOENT;}