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| author | Chang S. Bae <chang.seok.bae@intel.com> | 2022-07-18 11:56:11 -0700 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2022-07-19 19:17:28 +0200 |
| commit | 9f01129382774d98ec21526f13da26a0630ee3d8 (patch) | |
| tree | eb115f50dc16ab7371c6b792181a261b6da0658f /drivers/idle | |
| parent | f17b168734c0fe47343a7502d012266a051f9942 (diff) | |
| download | linux-9f01129382774d98ec21526f13da26a0630ee3d8.tar.gz linux-9f01129382774d98ec21526f13da26a0630ee3d8.tar.bz2 linux-9f01129382774d98ec21526f13da26a0630ee3d8.zip | |
intel_idle: Add a new flag to initialize the AMX state
The non-initialized AMX state can be the cause of C-state demotion from C6
to C1E. This low-power idle state may improve power savings and thus result
in a higher available turbo frequency budget.
This behavior is implementation-specific. Initialize the state for the C6
entrance of Sapphire Rapids as needed.
Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Zhang Rui <rui.zhang@intel.com>
Link: https://lkml.kernel.org/r/20220614164116.5196-1-chang.seok.bae@intel.com
Diffstat (limited to 'drivers/idle')
| -rw-r--r-- | drivers/idle/intel_idle.c | 25 |
1 files changed, 23 insertions, 2 deletions
diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c index f5c6802aa6c3..1ec221079367 100644 --- a/drivers/idle/intel_idle.c +++ b/drivers/idle/intel_idle.c @@ -56,6 +56,7 @@ #include <asm/nospec-branch.h> #include <asm/mwait.h> #include <asm/msr.h> +#include <asm/fpu/api.h> #define INTEL_IDLE_VERSION "0.5.1" @@ -114,6 +115,11 @@ static unsigned int mwait_substates __initdata; #define CPUIDLE_FLAG_IBRS BIT(16) /* + * Initialize large xstate for the C6-state entrance. + */ +#define CPUIDLE_FLAG_INIT_XSTATE BIT(17) + +/* * MWAIT takes an 8-bit "hint" in EAX "suggesting" * the C-state (top nibble) and sub-state (bottom nibble) * 0x00 means "MWAIT(C1)", 0x10 means "MWAIT(C2)" etc. @@ -185,6 +191,13 @@ static __cpuidle int intel_idle_ibrs(struct cpuidle_device *dev, return ret; } +static __cpuidle int intel_idle_xstate(struct cpuidle_device *dev, + struct cpuidle_driver *drv, int index) +{ + fpu_idle_fpregs(); + return __intel_idle(dev, drv, index); +} + /** * intel_idle_s2idle - Ask the processor to enter the given idle state. * @dev: cpuidle device of the target CPU. @@ -200,8 +213,12 @@ static __cpuidle int intel_idle_ibrs(struct cpuidle_device *dev, static __cpuidle int intel_idle_s2idle(struct cpuidle_device *dev, struct cpuidle_driver *drv, int index) { - unsigned long eax = flg2MWAIT(drv->states[index].flags); unsigned long ecx = 1; /* break on interrupt flag */ + struct cpuidle_state *state = &drv->states[index]; + unsigned long eax = flg2MWAIT(state->flags); + + if (state->flags & CPUIDLE_FLAG_INIT_XSTATE) + fpu_idle_fpregs(); mwait_idle_with_hints(eax, ecx); @@ -936,7 +953,8 @@ static struct cpuidle_state spr_cstates[] __initdata = { { .name = "C6", .desc = "MWAIT 0x20", - .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED, + .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED | + CPUIDLE_FLAG_INIT_XSTATE, .exit_latency = 290, .target_residency = 800, .enter = &intel_idle, @@ -1851,6 +1869,9 @@ static void __init intel_idle_init_cstates_icpu(struct cpuidle_driver *drv) drv->states[drv->state_count].enter = intel_idle_ibrs; } + if (cpuidle_state_table[cstate].flags & CPUIDLE_FLAG_INIT_XSTATE) + drv->states[drv->state_count].enter = intel_idle_xstate; + if ((disabled_states_mask & BIT(drv->state_count)) || ((icpu->use_acpi || force_use_acpi) && intel_idle_off_by_default(mwait_hint) && |