On Tue, 30 Jul 2024, Marek Maslanka wrote: > Allow to disable ACPI PM Timer on suspend and enable on resume. A > disabled timer helps optimise power consumption when the system is > suspended. On resume the timer is only reactivated if it was activated > prior to suspend, so unless the ACPI PM timer is enabled in the BIOS, > this won't change anything. > > Signed-off-by: Marek Maslanka <mmaslanka@xxxxxxxxxx> > > --- > Changes in v3: > - Add the clocksource_current_cs_name and clocksource_suspend_cs_name to the clocksource.c > - Do not disable the ACPI PM timer if it's selected as the clocksource > - Link to v2: https://lore.kernel.org/lkml/20240703113850.2726539-1-mmaslanka@xxxxxxxxxx/ > --- > --- > drivers/platform/x86/intel/pmc/adl.c | 2 ++ > drivers/platform/x86/intel/pmc/cnp.c | 2 ++ > drivers/platform/x86/intel/pmc/core.c | 47 +++++++++++++++++++++++++++ > drivers/platform/x86/intel/pmc/core.h | 8 +++++ > drivers/platform/x86/intel/pmc/icl.c | 2 ++ > drivers/platform/x86/intel/pmc/mtl.c | 2 ++ > drivers/platform/x86/intel/pmc/spt.c | 2 ++ > drivers/platform/x86/intel/pmc/tgl.c | 2 ++ > include/linux/clocksource.h | 2 ++ > kernel/time/clocksource.c | 22 +++++++++++++ > 10 files changed, 91 insertions(+) > > diff --git a/drivers/platform/x86/intel/pmc/adl.c b/drivers/platform/x86/intel/pmc/adl.c > index e7878558fd909..9d9c07f44ff61 100644 > --- a/drivers/platform/x86/intel/pmc/adl.c > +++ b/drivers/platform/x86/intel/pmc/adl.c > @@ -295,6 +295,8 @@ const struct pmc_reg_map adl_reg_map = { > .ppfear_buckets = CNP_PPFEAR_NUM_ENTRIES, > .pm_cfg_offset = CNP_PMC_PM_CFG_OFFSET, > .pm_read_disable_bit = CNP_PMC_READ_DISABLE_BIT, > + .acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET, > + .acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE, > .ltr_ignore_max = ADL_NUM_IP_IGN_ALLOWED, > .lpm_num_modes = ADL_LPM_NUM_MODES, > .lpm_num_maps = ADL_LPM_NUM_MAPS, > diff --git a/drivers/platform/x86/intel/pmc/cnp.c b/drivers/platform/x86/intel/pmc/cnp.c > index dd72974bf71e2..513c02670c5aa 100644 > --- a/drivers/platform/x86/intel/pmc/cnp.c > +++ b/drivers/platform/x86/intel/pmc/cnp.c > @@ -200,6 +200,8 @@ const struct pmc_reg_map cnp_reg_map = { > .ppfear_buckets = CNP_PPFEAR_NUM_ENTRIES, > .pm_cfg_offset = CNP_PMC_PM_CFG_OFFSET, > .pm_read_disable_bit = CNP_PMC_READ_DISABLE_BIT, > + .acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET, > + .acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE, > .ltr_ignore_max = CNP_NUM_IP_IGN_ALLOWED, > .etr3_offset = ETR3_OFFSET, > }; > diff --git a/drivers/platform/x86/intel/pmc/core.c b/drivers/platform/x86/intel/pmc/core.c > index 10c96c1a850af..1a435f5ca08c5 100644 > --- a/drivers/platform/x86/intel/pmc/core.c > +++ b/drivers/platform/x86/intel/pmc/core.c > @@ -12,6 +12,7 @@ > #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt > > #include <linux/bitfield.h> > +#include <linux/clocksource.h> > #include <linux/debugfs.h> > #include <linux/delay.h> > #include <linux/dmi.h> > @@ -1171,6 +1172,44 @@ static bool pmc_core_is_pson_residency_enabled(struct pmc_dev *pmcdev) > return val == 1; > } > > +/* > + * Enable or disable APCI PM Timer > + * > + * @return: Previous APCI PM Timer enabled state > + */ > +static bool pmc_core_enable_apci_pm_timer(struct pmc_dev *pmcdev, bool enable) > +{ > + struct pmc *pmc = pmcdev->pmcs[PMC_IDX_MAIN]; > + const struct pmc_reg_map *map = pmc->map; > + char cs_name[32]; > + bool state; > + u32 reg; > + > + if (!map->acpi_pm_tmr_ctl_offset) > + return false; > + > + clocksource_current_cs_name(cs_name, sizeof(cs_name)); > + if (strncmp(cs_name, "acpi_pm", sizeof(cs_name)) == 0) If you want to do a prefix check, there's str_has_prefix() for that. Otherwise, I don't understand why you need the n variant? > + return false; > + > + clocksource_suspend_cs_name(cs_name, sizeof(cs_name)); > + if (strncmp(cs_name, "acpi_pm", sizeof(cs_name)) == 0) > + return false; > + > + mutex_lock(&pmcdev->lock); > + > + reg = pmc_core_reg_read(pmc, map->acpi_pm_tmr_ctl_offset); > + state = !(reg & map->acpi_pm_tmr_disable_bit); > + if (enable) > + reg &= ~map->acpi_pm_tmr_disable_bit; > + else > + reg |= map->acpi_pm_tmr_disable_bit; > + pmc_core_reg_write(pmc, map->acpi_pm_tmr_ctl_offset, reg); > + > + mutex_unlock(&pmcdev->lock); > + > + return state; > +} > > static void pmc_core_dbgfs_unregister(struct pmc_dev *pmcdev) > { > @@ -1446,6 +1485,10 @@ static __maybe_unused int pmc_core_suspend(struct device *dev) > if (pmcdev->suspend) > pmcdev->suspend(pmcdev); > > + /* Disable APCI PM Timer */ > + pmcdev->enable_acpi_pm_timer_on_resume = > + pmc_core_enable_apci_pm_timer(pmcdev, false); > + > /* Check if the syspend will actually use S0ix */ > if (pm_suspend_via_firmware()) > return 0; > @@ -1500,6 +1543,10 @@ int pmc_core_resume_common(struct pmc_dev *pmcdev) > int offset = pmc->map->lpm_status_offset; > int i; > > + /* Enable APCI PM Timer */ > + if (pmcdev->enable_acpi_pm_timer_on_resume) > + pmc_core_enable_apci_pm_timer(pmcdev, true); > + > /* Check if the syspend used S0ix */ > if (pm_suspend_via_firmware()) > return 0; > diff --git a/drivers/platform/x86/intel/pmc/core.h b/drivers/platform/x86/intel/pmc/core.h > index 83504c49a0e31..fe1a94f693b63 100644 > --- a/drivers/platform/x86/intel/pmc/core.h > +++ b/drivers/platform/x86/intel/pmc/core.h > @@ -67,6 +67,8 @@ struct telem_endpoint; > #define SPT_PMC_LTR_SCC 0x3A0 > #define SPT_PMC_LTR_ISH 0x3A4 > > +#define SPT_PMC_ACPI_PM_TMR_CTL_OFFSET 0x18FC > + > /* Sunrise Point: PGD PFET Enable Ack Status Registers */ > enum ppfear_regs { > SPT_PMC_XRAM_PPFEAR0A = 0x590, > @@ -147,6 +149,8 @@ enum ppfear_regs { > #define SPT_PMC_VRIC1_SLPS0LVEN BIT(13) > #define SPT_PMC_VRIC1_XTALSDQDIS BIT(22) > > +#define SPT_PMC_BIT_ACPI_PM_TMR_DISABLE BIT(1) > + > /* Cannonlake Power Management Controller register offsets */ > #define CNP_PMC_SLPS0_DBG_OFFSET 0x10B4 > #define CNP_PMC_PM_CFG_OFFSET 0x1818 > @@ -344,6 +348,8 @@ struct pmc_reg_map { > const u8 *lpm_reg_index; > const u32 pson_residency_offset; > const u32 pson_residency_counter_step; > + const u32 acpi_pm_tmr_ctl_offset; > + const u32 acpi_pm_tmr_disable_bit; > }; > > /** > @@ -417,6 +423,8 @@ struct pmc_dev { > u32 die_c6_offset; > struct telem_endpoint *punit_ep; > struct pmc_info *regmap_list; > + > + bool enable_acpi_pm_timer_on_resume; > }; > > enum pmc_index { > diff --git a/drivers/platform/x86/intel/pmc/icl.c b/drivers/platform/x86/intel/pmc/icl.c > index 71b0fd6cb7d84..cbbd440544688 100644 > --- a/drivers/platform/x86/intel/pmc/icl.c > +++ b/drivers/platform/x86/intel/pmc/icl.c > @@ -46,6 +46,8 @@ const struct pmc_reg_map icl_reg_map = { > .ppfear_buckets = ICL_PPFEAR_NUM_ENTRIES, > .pm_cfg_offset = CNP_PMC_PM_CFG_OFFSET, > .pm_read_disable_bit = CNP_PMC_READ_DISABLE_BIT, > + .acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET, > + .acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE, > .ltr_ignore_max = ICL_NUM_IP_IGN_ALLOWED, > .etr3_offset = ETR3_OFFSET, > }; > diff --git a/drivers/platform/x86/intel/pmc/mtl.c b/drivers/platform/x86/intel/pmc/mtl.c > index c7d15d864039d..91f2fa728f5c8 100644 > --- a/drivers/platform/x86/intel/pmc/mtl.c > +++ b/drivers/platform/x86/intel/pmc/mtl.c > @@ -462,6 +462,8 @@ const struct pmc_reg_map mtl_socm_reg_map = { > .ppfear_buckets = MTL_SOCM_PPFEAR_NUM_ENTRIES, > .pm_cfg_offset = CNP_PMC_PM_CFG_OFFSET, > .pm_read_disable_bit = CNP_PMC_READ_DISABLE_BIT, > + .acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET, > + .acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE, > .lpm_num_maps = ADL_LPM_NUM_MAPS, > .ltr_ignore_max = MTL_SOCM_NUM_IP_IGN_ALLOWED, > .lpm_res_counter_step_x2 = TGL_PMC_LPM_RES_COUNTER_STEP_X2, > diff --git a/drivers/platform/x86/intel/pmc/spt.c b/drivers/platform/x86/intel/pmc/spt.c > index ab993a69e33ee..2cd2b3c68e468 100644 > --- a/drivers/platform/x86/intel/pmc/spt.c > +++ b/drivers/platform/x86/intel/pmc/spt.c > @@ -130,6 +130,8 @@ const struct pmc_reg_map spt_reg_map = { > .ppfear_buckets = SPT_PPFEAR_NUM_ENTRIES, > .pm_cfg_offset = SPT_PMC_PM_CFG_OFFSET, > .pm_read_disable_bit = SPT_PMC_READ_DISABLE_BIT, > + .acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET, > + .acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE, > .ltr_ignore_max = SPT_NUM_IP_IGN_ALLOWED, > .pm_vric1_offset = SPT_PMC_VRIC1_OFFSET, > }; > diff --git a/drivers/platform/x86/intel/pmc/tgl.c b/drivers/platform/x86/intel/pmc/tgl.c > index e0580de180773..371b4e30f1426 100644 > --- a/drivers/platform/x86/intel/pmc/tgl.c > +++ b/drivers/platform/x86/intel/pmc/tgl.c > @@ -197,6 +197,8 @@ const struct pmc_reg_map tgl_reg_map = { > .ppfear_buckets = ICL_PPFEAR_NUM_ENTRIES, > .pm_cfg_offset = CNP_PMC_PM_CFG_OFFSET, > .pm_read_disable_bit = CNP_PMC_READ_DISABLE_BIT, > + .acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET, > + .acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE, > .ltr_ignore_max = TGL_NUM_IP_IGN_ALLOWED, > .lpm_num_maps = TGL_LPM_NUM_MAPS, > .lpm_res_counter_step_x2 = TGL_PMC_LPM_RES_COUNTER_STEP_X2, > diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h > index 0ad8b550bb4b4..f1953c5687683 100644 > --- a/include/linux/clocksource.h > +++ b/include/linux/clocksource.h > @@ -305,5 +305,7 @@ static inline unsigned int clocksource_get_max_watchdog_retry(void) > } > > void clocksource_verify_percpu(struct clocksource *cs); > +void clocksource_current_cs_name(char *buf, size_t buf_size); > +void clocksource_suspend_cs_name(char *buf, size_t buf_size); > > #endif /* _LINUX_CLOCKSOURCE_H */ > diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c > index e5b260aa0e02c..e2e2609f7f4b2 100644 > --- a/kernel/time/clocksource.c > +++ b/kernel/time/clocksource.c > @@ -1320,6 +1320,28 @@ int clocksource_unregister(struct clocksource *cs) > } > EXPORT_SYMBOL(clocksource_unregister); > > +void clocksource_suspend_cs_name(char *buf, size_t buf_size) > +{ > + mutex_lock(&clocksource_mutex); > + > + buf[0] = '\0'; > + if (suspend_clocksource) > + strscpy(buf, suspend_clocksource->name, buf_size); > + > + mutex_unlock(&clocksource_mutex); > +} > + > +void clocksource_current_cs_name(char *buf, size_t buf_size) > +{ > + mutex_lock(&clocksource_mutex); > + > + buf[0] = '\0'; > + if (curr_clocksource) > + strscpy(buf, curr_clocksource->name, buf_size); > + > + mutex_unlock(&clocksource_mutex); > +} Have you tested allmodconfig build? These functions are not exported so I'd expect it to fail... One could use guard() for the mutex. -- i.
