Messages in this thread Patch in this message | | | From | y00318929 <> | Subject | [PATCH 3/5] arm64: mm: Use cpumask in flush_context() | Date | Mon, 17 Oct 2022 16:12:56 +0800 |
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From: Yunfeng Ye <yeyunfeng@huawei.com>
Currently, all CPUs are selected to flush TLB in flush_context(). In order to prepare for flushing only part of the CPUs TLB, we use asid_housekeeping_mask and use cpumask_or() instead of cpumask_setall().
Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com> --- arch/arm64/mm/context.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/mm/context.c b/arch/arm64/mm/context.c index 380c7b05c36b..e402997aa1c2 100644 --- a/arch/arm64/mm/context.c +++ b/arch/arm64/mm/context.c @@ -11,6 +11,7 @@ #include <linux/sched.h> #include <linux/slab.h> #include <linux/mm.h> +#include <linux/cpumask.h> #include <asm/cpufeature.h> #include <asm/mmu_context.h> @@ -32,6 +33,7 @@ static unsigned long *asid_map; static DEFINE_PER_CPU(atomic64_t, active_asids); static DEFINE_PER_CPU(u64, reserved_asids); static cpumask_t tlb_flush_pending; +static const struct cpumask *asid_housekeeping_mask; static struct asid_bitmap pinned_asid; @@ -129,17 +131,23 @@ static inline bool asid_gen_match(u64 asid) return asid_match(asid, asid_read_generation()); } +static const struct cpumask *flush_cpumask(void) +{ + return asid_housekeeping_mask; +} + static void flush_context(void) { int i; u64 asid; + const struct cpumask *cpumask = flush_cpumask(); flush_generation(); /* Update the list of reserved ASIDs and the ASID bitmap. */ set_reserved_asid_bits(); - for_each_possible_cpu(i) { + for_each_cpu(i, cpumask) { asid = atomic64_xchg_relaxed(&per_cpu(active_asids, i), 0); /* * If this CPU has already been through a @@ -158,7 +166,7 @@ static void flush_context(void) * Queue a TLB invalidation for each CPU to perform on next * context-switch */ - cpumask_setall(&tlb_flush_pending); + cpumask_or(&tlb_flush_pending, &tlb_flush_pending, cpumask); } static bool check_update_reserved_asid(u64 asid, u64 newasid) @@ -439,6 +447,8 @@ static int asids_init(void) pinned_asid.map = bitmap_zalloc(NUM_USER_ASIDS, GFP_KERNEL); pinned_asid.nr = 0; + asid_housekeeping_mask = cpu_possible_mask; + /* * We cannot call set_reserved_asid_bits() here because CPU * caps are not finalized yet, so it is safer to assume KPTI -- 2.27.0
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