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author | Takashi Iwai <tiwai@suse.de> | 2017-11-01 17:43:20 +0100 |
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committer | Takashi Iwai <tiwai@suse.de> | 2017-11-01 17:43:20 +0100 |
commit | a53a0ab8ff725672fcb47bb9a5ef75fce45679d0 (patch) | |
tree | 75cdea78f27fdd569d72cea0b7837bbcc8d871f7 /arch/x86/include/asm/tlbflush.h | |
parent | 1f20f9ff57ca23b9f5502fca85ce3977e8496cb1 (diff) | |
parent | b817d936248b9bcee8282e97fb1dda1b03c903fe (diff) | |
download | linux-a53a0ab8ff725672fcb47bb9a5ef75fce45679d0.tar.bz2 |
Merge tag 'asoc-fix-v4.14-rc7' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-linus
ASoC: Fixes for v4.14
A bunch of fixes here, mostly device specific ones (the biggest one
being the revert of the hotword support for rt5514), with a couple of
core fixes for potential issues with corrupted or otherwise invalid
topology files.
Diffstat (limited to 'arch/x86/include/asm/tlbflush.h')
-rw-r--r-- | arch/x86/include/asm/tlbflush.h | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/arch/x86/include/asm/tlbflush.h b/arch/x86/include/asm/tlbflush.h index 4893abf7f74f..c4aed0de565e 100644 --- a/arch/x86/include/asm/tlbflush.h +++ b/arch/x86/include/asm/tlbflush.h @@ -82,6 +82,22 @@ static inline u64 inc_mm_tlb_gen(struct mm_struct *mm) #define __flush_tlb_single(addr) __native_flush_tlb_single(addr) #endif +static inline bool tlb_defer_switch_to_init_mm(void) +{ + /* + * If we have PCID, then switching to init_mm is reasonably + * fast. If we don't have PCID, then switching to init_mm is + * quite slow, so we try to defer it in the hopes that we can + * avoid it entirely. The latter approach runs the risk of + * receiving otherwise unnecessary IPIs. + * + * This choice is just a heuristic. The tlb code can handle this + * function returning true or false regardless of whether we have + * PCID. + */ + return !static_cpu_has(X86_FEATURE_PCID); +} + /* * 6 because 6 should be plenty and struct tlb_state will fit in * two cache lines. @@ -105,6 +121,23 @@ struct tlb_state { u16 next_asid; /* + * We can be in one of several states: + * + * - Actively using an mm. Our CPU's bit will be set in + * mm_cpumask(loaded_mm) and is_lazy == false; + * + * - Not using a real mm. loaded_mm == &init_mm. Our CPU's bit + * will not be set in mm_cpumask(&init_mm) and is_lazy == false. + * + * - Lazily using a real mm. loaded_mm != &init_mm, our bit + * is set in mm_cpumask(loaded_mm), but is_lazy == true. + * We're heuristically guessing that the CR3 load we + * skipped more than makes up for the overhead added by + * lazy mode. + */ + bool is_lazy; + + /* * Access to this CR4 shadow and to H/W CR4 is protected by * disabling interrupts when modifying either one. */ |