| Message ID | 20211206122952.74139-3-kirill.shutemov@linux.intel.com (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
| Series | ACPI/ACPICA: Only flush caches on S1/S2/S3 and C3 | expand |
On Mon, Dec 6, 2021 at 1:30 PM Kirill A. Shutemov <kirill.shutemov@linux.intel.com> wrote: > > ACPICA code takes care about cache flushing on S1/S2/S3 in > acpi_hw_extended_sleep() and acpi_hw_legacy_sleep(). > > acpi_suspend_enter() calls into ACPICA code via acpi_enter_sleep_state() > for S1 or x86_acpi_suspend_lowlevel() for S3. It only need to flush > cache for S2 (not sure if this call path is ever used for S2). > > acpi_sleep_prepare() call tree: > __acpi_pm_prepare() > acpi_pm_prepare() > acpi_suspend_ops::prepare_late() > acpi_hibernation_ops::pre_snapshot() > acpi_hibernation_ops::prepare() > acpi_suspend_begin_old() > acpi_suspend_begin_old::begin() > acpi_hibernation_begin_old() > acpi_hibernation_ops_old::acpi_hibernation_begin_old() > acpi_power_off_prepare() > pm_power_off_prepare() > > Hibernation (S4) and Power Off (S5) don't require cache flushing. So, > the only interesting callsites are acpi_suspend_ops::prepare_late() and > acpi_suspend_begin_old::begin(). Both of them have cache flush on > ->enter() operation in acpi_suspend_enter(). > > Remove redundant ACPI_FLUSH_CPU_CACHE() in acpi_sleep_prepare() and > acpi_suspend_enter(). > > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> > --- > drivers/acpi/sleep.c | 7 +++---- > 1 file changed, 3 insertions(+), 4 deletions(-) > > diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c > index eaa47753b758..14e8df0ac762 100644 > --- a/drivers/acpi/sleep.c > +++ b/drivers/acpi/sleep.c > @@ -73,7 +73,6 @@ static int acpi_sleep_prepare(u32 acpi_state) > acpi_set_waking_vector(acpi_wakeup_address); > > } > - ACPI_FLUSH_CPU_CACHE(); > #endif > pr_info("Preparing to enter system sleep state S%d\n", acpi_state); > acpi_enable_wakeup_devices(acpi_state); > @@ -566,15 +565,15 @@ static int acpi_suspend_enter(suspend_state_t pm_state) > u32 acpi_state = acpi_target_sleep_state; > int error; > > - ACPI_FLUSH_CPU_CACHE(); > - > trace_suspend_resume(TPS("acpi_suspend"), acpi_state, true); > switch (acpi_state) { > case ACPI_STATE_S1: > barrier(); > status = acpi_enter_sleep_state(acpi_state); > break; > - > + case ACPI_STATE_S2: > + ACPI_FLUSH_CPU_CACHE(); > + break; I don't think this is needed for S2, because the function doesn't do anything low-level in that case and simply returns (IOW, S2 isn't really supported). > case ACPI_STATE_S3: > if (!acpi_suspend_lowlevel) > return -ENOSYS; > -- > 2.32.0 >
On Tue, Dec 07, 2021 at 05:35:38PM +0100, Rafael J. Wysocki wrote: > I don't think this is needed for S2, because the function doesn't do > anything low-level in that case and simply returns (IOW, S2 isn't > really supported). Updated patch is below. Does it look good? From 5eb4ec7d8dd463ba186b779dcef2a802d999c59c Mon Sep 17 00:00:00 2001 From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Date: Thu, 9 Dec 2021 16:08:02 +0300 Subject: [PATCH 1/2] ACPI: PM: Remove redundant cache flushing ACPICA code takes care about cache flushing on S1/S2/S3 in acpi_hw_extended_sleep() and acpi_hw_legacy_sleep(). acpi_suspend_enter() calls into ACPICA code via acpi_enter_sleep_state() for S1 or x86_acpi_suspend_lowlevel() for S3. acpi_sleep_prepare() call tree: __acpi_pm_prepare() acpi_pm_prepare() acpi_suspend_ops::prepare_late() acpi_hibernation_ops::pre_snapshot() acpi_hibernation_ops::prepare() acpi_suspend_begin_old() acpi_suspend_begin_old::begin() acpi_hibernation_begin_old() acpi_hibernation_ops_old::acpi_hibernation_begin_old() acpi_power_off_prepare() pm_power_off_prepare() Hibernation (S4) and Power Off (S5) don't require cache flushing. So, the only interesting callsites are acpi_suspend_ops::prepare_late() and acpi_suspend_begin_old::begin(). Both of them have cache flush on ->enter() operation in acpi_suspend_enter(). Remove redundant ACPI_FLUSH_CPU_CACHE() in acpi_sleep_prepare() and acpi_suspend_enter(). Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> --- drivers/acpi/sleep.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c index eaa47753b758..5ca6c223ba3d 100644 --- a/drivers/acpi/sleep.c +++ b/drivers/acpi/sleep.c @@ -73,7 +73,6 @@ static int acpi_sleep_prepare(u32 acpi_state) acpi_set_waking_vector(acpi_wakeup_address); } - ACPI_FLUSH_CPU_CACHE(); #endif pr_info("Preparing to enter system sleep state S%d\n", acpi_state); acpi_enable_wakeup_devices(acpi_state); @@ -566,8 +565,6 @@ static int acpi_suspend_enter(suspend_state_t pm_state) u32 acpi_state = acpi_target_sleep_state; int error; - ACPI_FLUSH_CPU_CACHE(); - trace_suspend_resume(TPS("acpi_suspend"), acpi_state, true); switch (acpi_state) { case ACPI_STATE_S1:
On Thu, Dec 9, 2021 at 2:32 PM Kirill A. Shutemov <kirill.shutemov@linux.intel.com> wrote: > > On Tue, Dec 07, 2021 at 05:35:38PM +0100, Rafael J. Wysocki wrote: > > I don't think this is needed for S2, because the function doesn't do > > anything low-level in that case and simply returns (IOW, S2 isn't > > really supported). > > Updated patch is below. Does it look good? It does, and so applied as 5.17 material with some minor edits in the changelog. Thanks! > From 5eb4ec7d8dd463ba186b779dcef2a802d999c59c Mon Sep 17 00:00:00 2001 > From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> > Date: Thu, 9 Dec 2021 16:08:02 +0300 > Subject: [PATCH 1/2] ACPI: PM: Remove redundant cache flushing > > ACPICA code takes care about cache flushing on S1/S2/S3 in > acpi_hw_extended_sleep() and acpi_hw_legacy_sleep(). > > acpi_suspend_enter() calls into ACPICA code via acpi_enter_sleep_state() > for S1 or x86_acpi_suspend_lowlevel() for S3. > > acpi_sleep_prepare() call tree: > __acpi_pm_prepare() > acpi_pm_prepare() > acpi_suspend_ops::prepare_late() > acpi_hibernation_ops::pre_snapshot() > acpi_hibernation_ops::prepare() > acpi_suspend_begin_old() > acpi_suspend_begin_old::begin() > acpi_hibernation_begin_old() > acpi_hibernation_ops_old::acpi_hibernation_begin_old() > acpi_power_off_prepare() > pm_power_off_prepare() > > Hibernation (S4) and Power Off (S5) don't require cache flushing. So, > the only interesting callsites are acpi_suspend_ops::prepare_late() and > acpi_suspend_begin_old::begin(). Both of them have cache flush on > ->enter() operation in acpi_suspend_enter(). > > Remove redundant ACPI_FLUSH_CPU_CACHE() in acpi_sleep_prepare() and > acpi_suspend_enter(). > > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> > --- > drivers/acpi/sleep.c | 3 --- > 1 file changed, 3 deletions(-) > > diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c > index eaa47753b758..5ca6c223ba3d 100644 > --- a/drivers/acpi/sleep.c > +++ b/drivers/acpi/sleep.c > @@ -73,7 +73,6 @@ static int acpi_sleep_prepare(u32 acpi_state) > acpi_set_waking_vector(acpi_wakeup_address); > > } > - ACPI_FLUSH_CPU_CACHE(); > #endif > pr_info("Preparing to enter system sleep state S%d\n", acpi_state); > acpi_enable_wakeup_devices(acpi_state); > @@ -566,8 +565,6 @@ static int acpi_suspend_enter(suspend_state_t pm_state) > u32 acpi_state = acpi_target_sleep_state; > int error; > > - ACPI_FLUSH_CPU_CACHE(); > - > trace_suspend_resume(TPS("acpi_suspend"), acpi_state, true); > switch (acpi_state) { > case ACPI_STATE_S1: > -- > Kirill A. Shutemov
diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c index eaa47753b758..14e8df0ac762 100644 --- a/drivers/acpi/sleep.c +++ b/drivers/acpi/sleep.c @@ -73,7 +73,6 @@ static int acpi_sleep_prepare(u32 acpi_state) acpi_set_waking_vector(acpi_wakeup_address); } - ACPI_FLUSH_CPU_CACHE(); #endif pr_info("Preparing to enter system sleep state S%d\n", acpi_state); acpi_enable_wakeup_devices(acpi_state); @@ -566,15 +565,15 @@ static int acpi_suspend_enter(suspend_state_t pm_state) u32 acpi_state = acpi_target_sleep_state; int error; - ACPI_FLUSH_CPU_CACHE(); - trace_suspend_resume(TPS("acpi_suspend"), acpi_state, true); switch (acpi_state) { case ACPI_STATE_S1: barrier(); status = acpi_enter_sleep_state(acpi_state); break; - + case ACPI_STATE_S2: + ACPI_FLUSH_CPU_CACHE(); + break; case ACPI_STATE_S3: if (!acpi_suspend_lowlevel) return -ENOSYS;
ACPICA code takes care about cache flushing on S1/S2/S3 in acpi_hw_extended_sleep() and acpi_hw_legacy_sleep(). acpi_suspend_enter() calls into ACPICA code via acpi_enter_sleep_state() for S1 or x86_acpi_suspend_lowlevel() for S3. It only need to flush cache for S2 (not sure if this call path is ever used for S2). acpi_sleep_prepare() call tree: __acpi_pm_prepare() acpi_pm_prepare() acpi_suspend_ops::prepare_late() acpi_hibernation_ops::pre_snapshot() acpi_hibernation_ops::prepare() acpi_suspend_begin_old() acpi_suspend_begin_old::begin() acpi_hibernation_begin_old() acpi_hibernation_ops_old::acpi_hibernation_begin_old() acpi_power_off_prepare() pm_power_off_prepare() Hibernation (S4) and Power Off (S5) don't require cache flushing. So, the only interesting callsites are acpi_suspend_ops::prepare_late() and acpi_suspend_begin_old::begin(). Both of them have cache flush on ->enter() operation in acpi_suspend_enter(). Remove redundant ACPI_FLUSH_CPU_CACHE() in acpi_sleep_prepare() and acpi_suspend_enter(). Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> --- drivers/acpi/sleep.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-)