diff options
| -rw-r--r-- | Documentation/acpi/lpit.txt | 25 | ||||
| -rw-r--r-- | drivers/acpi/Kconfig | 5 | ||||
| -rw-r--r-- | drivers/acpi/Makefile | 1 | ||||
| -rw-r--r-- | drivers/acpi/acpi_lpit.c | 162 | ||||
| -rw-r--r-- | drivers/acpi/internal.h | 6 | ||||
| -rw-r--r-- | drivers/acpi/osl.c | 42 | ||||
| -rw-r--r-- | drivers/acpi/scan.c | 1 | ||||
| -rw-r--r-- | include/acpi/acpiosxf.h | 2 | ||||
| -rw-r--r-- | include/linux/acpi.h | 9 |
9 files changed, 237 insertions, 16 deletions
diff --git a/Documentation/acpi/lpit.txt b/Documentation/acpi/lpit.txt new file mode 100644 index 000000000000..b426398d2e97 --- /dev/null +++ b/Documentation/acpi/lpit.txt @@ -0,0 +1,25 @@ +To enumerate platform Low Power Idle states, Intel platforms are using +“Low Power Idle Table” (LPIT). More details about this table can be +downloaded from: +http://www.uefi.org/sites/default/files/resources/Intel_ACPI_Low_Power_S0_Idle.pdf + +Residencies for each low power state can be read via FFH +(Function fixed hardware) or a memory mapped interface. + +On platforms supporting S0ix sleep states, there can be two types of +residencies: +- CPU PKG C10 (Read via FFH interface) +- Platform Controller Hub (PCH) SLP_S0 (Read via memory mapped interface) + +The following attributes are added dynamically to the cpuidle +sysfs attribute group: + /sys/devices/system/cpu/cpuidle/low_power_idle_cpu_residency_us + /sys/devices/system/cpu/cpuidle/low_power_idle_system_residency_us + +The "low_power_idle_cpu_residency_us" attribute shows time spent +by the CPU package in PKG C10 + +The "low_power_idle_system_residency_us" attribute shows SLP_S0 +residency, or system time spent with the SLP_S0# signal asserted. +This is the lowest possible system power state, achieved only when CPU is in +PKG C10 and all functional blocks in PCH are in a low power state. diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig index 1ce52f84dc23..4bfef0f78cde 100644 --- a/drivers/acpi/Kconfig +++ b/drivers/acpi/Kconfig @@ -80,6 +80,11 @@ endif config ACPI_SPCR_TABLE bool +config ACPI_LPIT + bool + depends on X86_64 + default y + config ACPI_SLEEP bool depends on SUSPEND || HIBERNATION diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile index 90265ab4437a..6a19bd7aba21 100644 --- a/drivers/acpi/Makefile +++ b/drivers/acpi/Makefile @@ -56,6 +56,7 @@ acpi-$(CONFIG_DEBUG_FS) += debugfs.o acpi-$(CONFIG_ACPI_NUMA) += numa.o acpi-$(CONFIG_ACPI_PROCFS_POWER) += cm_sbs.o acpi-y += acpi_lpat.o +acpi-$(CONFIG_ACPI_LPIT) += acpi_lpit.o acpi-$(CONFIG_ACPI_GENERIC_GSI) += irq.o acpi-$(CONFIG_ACPI_WATCHDOG) += acpi_watchdog.o diff --git a/drivers/acpi/acpi_lpit.c b/drivers/acpi/acpi_lpit.c new file mode 100644 index 000000000000..e94e478dd18b --- /dev/null +++ b/drivers/acpi/acpi_lpit.c @@ -0,0 +1,162 @@ + +/* + * acpi_lpit.c - LPIT table processing functions + * + * Copyright (C) 2017 Intel Corporation. All rights reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License version + * 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#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; +} + +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_nocache(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; + u64 lpit_begin; + struct acpi_table_lpit *lpit; + + status = acpi_get_table(ACPI_SIG_LPIT, 0, (struct acpi_table_header **)&lpit); + + if (ACPI_FAILURE(status)) + return; + + lpit_begin = (u64)lpit + sizeof(*lpit); + lpit_process(lpit_begin, lpit_begin + lpit->header.length); +} diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h index 4361c4415b4f..fc8c43e76707 100644 --- a/drivers/acpi/internal.h +++ b/drivers/acpi/internal.h @@ -248,4 +248,10 @@ void acpi_watchdog_init(void); static inline void acpi_watchdog_init(void) {} #endif +#ifdef CONFIG_ACPI_LPIT +void acpi_init_lpit(void); +#else +static inline void acpi_init_lpit(void) { } +#endif + #endif /* _ACPI_INTERNAL_H_ */ diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c index db78d353bab1..3bb46cb24a99 100644 --- a/drivers/acpi/osl.c +++ b/drivers/acpi/osl.c @@ -663,6 +663,29 @@ acpi_status acpi_os_write_port(acpi_io_address port, u32 value, u32 width) EXPORT_SYMBOL(acpi_os_write_port); +int acpi_os_read_iomem(void __iomem *virt_addr, u64 *value, u32 width) +{ + + switch (width) { + case 8: + *(u8 *) value = readb(virt_addr); + break; + case 16: + *(u16 *) value = readw(virt_addr); + break; + case 32: + *(u32 *) value = readl(virt_addr); + break; + case 64: + *(u64 *) value = readq(virt_addr); + break; + default: + return -EINVAL; + } + + return 0; +} + acpi_status acpi_os_read_memory(acpi_physical_address phys_addr, u64 *value, u32 width) { @@ -670,6 +693,7 @@ acpi_os_read_memory(acpi_physical_address phys_addr, u64 *value, u32 width) unsigned int size = width / 8; bool unmap = false; u64 dummy; + int error; rcu_read_lock(); virt_addr = acpi_map_vaddr_lookup(phys_addr, size); @@ -684,22 +708,8 @@ acpi_os_read_memory(acpi_physical_address phys_addr, u64 *value, u32 width) if (!value) value = &dummy; - switch (width) { - case 8: - *(u8 *) value = readb(virt_addr); - break; - case 16: - *(u16 *) value = readw(virt_addr); - break; - case 32: - *(u32 *) value = readl(virt_addr); - break; - case 64: - *(u64 *) value = readq(virt_addr); - break; - default: - BUG(); - } + error = acpi_os_read_iomem(virt_addr, value, width); + BUG_ON(error); if (unmap) iounmap(virt_addr); diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 602f8ff212f2..81367edc8a10 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -2122,6 +2122,7 @@ int __init acpi_scan_init(void) acpi_int340x_thermal_init(); acpi_amba_init(); acpi_watchdog_init(); + acpi_init_lpit(); acpi_scan_add_handler(&generic_device_handler); diff --git a/include/acpi/acpiosxf.h b/include/acpi/acpiosxf.h index c66eb8ffa454..d5c0f5153c4e 100644 --- a/include/acpi/acpiosxf.h +++ b/include/acpi/acpiosxf.h @@ -287,6 +287,8 @@ acpi_status acpi_os_write_port(acpi_io_address address, u32 value, u32 width); /* * Platform and hardware-independent physical memory interfaces */ +int acpi_os_read_iomem(void __iomem *virt_addr, u64 *value, u32 width); + #ifndef ACPI_USE_ALTERNATE_PROTOTYPE_acpi_os_read_memory acpi_status acpi_os_read_memory(acpi_physical_address address, u64 *value, u32 width); diff --git a/include/linux/acpi.h b/include/linux/acpi.h index d18c92d4ba19..2b1738f840ab 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -1248,4 +1248,13 @@ int acpi_irq_get(acpi_handle handle, unsigned int index, struct resource *res) } #endif +#ifdef CONFIG_ACPI_LPIT +int lpit_read_residency_count_address(u64 *address); +#else +static inline int lpit_read_residency_count_address(u64 *address) +{ + return -EINVAL; +} +#endif + #endif /*_LINUX_ACPI_H*/ |