123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155 |
- // SPDX-License-Identifier: GPL-2.0-only
- /*
- * acpi_lpit.c - LPIT table processing functions
- *
- * Copyright (C) 2017 Intel Corporation. All rights reserved.
- */
- #include <linux/cpu.h>
- #include <linux/acpi.h>
- #include <asm/msr.h>
- #include <asm/tsc.h>
- struct lpit_residency_info {
- struct acpi_generic_address gaddr;
- u64 frequency;
- void __iomem *iomem_addr;
- };
- /* Storage for an memory mapped and FFH based entries */
- static struct lpit_residency_info residency_info_mem;
- static struct lpit_residency_info residency_info_ffh;
- static int lpit_read_residency_counter_us(u64 *counter, bool io_mem)
- {
- int err;
- if (io_mem) {
- u64 count = 0;
- int error;
- error = acpi_os_read_iomem(residency_info_mem.iomem_addr, &count,
- residency_info_mem.gaddr.bit_width);
- if (error)
- return error;
- *counter = div64_u64(count * 1000000ULL, residency_info_mem.frequency);
- return 0;
- }
- err = rdmsrl_safe(residency_info_ffh.gaddr.address, counter);
- if (!err) {
- u64 mask = GENMASK_ULL(residency_info_ffh.gaddr.bit_offset +
- residency_info_ffh.gaddr. bit_width - 1,
- residency_info_ffh.gaddr.bit_offset);
- *counter &= mask;
- *counter >>= residency_info_ffh.gaddr.bit_offset;
- *counter = div64_u64(*counter * 1000000ULL, residency_info_ffh.frequency);
- return 0;
- }
- return -ENODATA;
- }
- static ssize_t low_power_idle_system_residency_us_show(struct device *dev,
- struct device_attribute *attr,
- char *buf)
- {
- u64 counter;
- int ret;
- ret = lpit_read_residency_counter_us(&counter, true);
- if (ret)
- return ret;
- return sprintf(buf, "%llu\n", counter);
- }
- static DEVICE_ATTR_RO(low_power_idle_system_residency_us);
- static ssize_t low_power_idle_cpu_residency_us_show(struct device *dev,
- struct device_attribute *attr,
- char *buf)
- {
- u64 counter;
- int ret;
- ret = lpit_read_residency_counter_us(&counter, false);
- if (ret)
- return ret;
- return sprintf(buf, "%llu\n", counter);
- }
- static DEVICE_ATTR_RO(low_power_idle_cpu_residency_us);
- int lpit_read_residency_count_address(u64 *address)
- {
- if (!residency_info_mem.gaddr.address)
- return -EINVAL;
- *address = residency_info_mem.gaddr.address;
- return 0;
- }
- EXPORT_SYMBOL_GPL(lpit_read_residency_count_address);
- static void lpit_update_residency(struct lpit_residency_info *info,
- struct acpi_lpit_native *lpit_native)
- {
- info->frequency = lpit_native->counter_frequency ?
- lpit_native->counter_frequency : tsc_khz * 1000;
- if (!info->frequency)
- info->frequency = 1;
- info->gaddr = lpit_native->residency_counter;
- if (info->gaddr.space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) {
- info->iomem_addr = ioremap(info->gaddr.address,
- info->gaddr.bit_width / 8);
- if (!info->iomem_addr)
- return;
- /* Silently fail, if cpuidle attribute group is not present */
- sysfs_add_file_to_group(&cpu_subsys.dev_root->kobj,
- &dev_attr_low_power_idle_system_residency_us.attr,
- "cpuidle");
- } else if (info->gaddr.space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
- /* Silently fail, if cpuidle attribute group is not present */
- sysfs_add_file_to_group(&cpu_subsys.dev_root->kobj,
- &dev_attr_low_power_idle_cpu_residency_us.attr,
- "cpuidle");
- }
- }
- static void lpit_process(u64 begin, u64 end)
- {
- while (begin + sizeof(struct acpi_lpit_native) <= end) {
- struct acpi_lpit_native *lpit_native = (struct acpi_lpit_native *)begin;
- if (!lpit_native->header.type && !lpit_native->header.flags) {
- if (lpit_native->residency_counter.space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY &&
- !residency_info_mem.gaddr.address) {
- lpit_update_residency(&residency_info_mem, lpit_native);
- } else if (lpit_native->residency_counter.space_id == ACPI_ADR_SPACE_FIXED_HARDWARE &&
- !residency_info_ffh.gaddr.address) {
- lpit_update_residency(&residency_info_ffh, lpit_native);
- }
- }
- begin += lpit_native->header.length;
- }
- }
- void acpi_init_lpit(void)
- {
- acpi_status status;
- struct acpi_table_lpit *lpit;
- status = acpi_get_table(ACPI_SIG_LPIT, 0, (struct acpi_table_header **)&lpit);
- if (ACPI_FAILURE(status))
- return;
- lpit_process((u64)lpit + sizeof(*lpit),
- (u64)lpit + lpit->header.length);
- acpi_put_table((struct acpi_table_header *)lpit);
- }
|