Messages in this thread Patch in this message | | | From | y00318929 <> | Subject | [PATCH 2/5] arm64: mm: Extract the processing of asid_generation | Date | Mon, 17 Oct 2022 16:12:55 +0800 |
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From: Yunfeng Ye <yeyunfeng@huawei.com>
To prepare for supporting ASID isolation feature, extract the processing of asid_generation. it is convenient to modify the asid_generation centrally.
By the way, It is clearer to put flush_generation() into flush_context().
Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com> --- arch/arm64/mm/context.c | 39 ++++++++++++++++++++++++++++++++------- 1 file changed, 32 insertions(+), 7 deletions(-)
diff --git a/arch/arm64/mm/context.c b/arch/arm64/mm/context.c index 8549b5f30352..380c7b05c36b 100644 --- a/arch/arm64/mm/context.c +++ b/arch/arm64/mm/context.c @@ -102,14 +102,40 @@ static void set_reserved_asid_bits(void) bitmap_clear(asid_map, 0, NUM_USER_ASIDS); } -#define asid_gen_match(asid) \ - (!(((asid) ^ atomic64_read(&asid_generation)) >> asid_bits)) +static void asid_generation_init(void) +{ + atomic64_set(&asid_generation, ASID_FIRST_VERSION); +} + +static void flush_generation(void) +{ + /* We're out of ASIDs, so increment the global generation count */ + atomic64_add_return_relaxed(ASID_FIRST_VERSION, + &asid_generation); +} + +static inline u64 asid_read_generation(void) +{ + return atomic64_read(&asid_generation); +} + +static inline bool asid_match(u64 asid, u64 genid) +{ + return (!(((asid) ^ (genid)) >> asid_bits)); +} + +static inline bool asid_gen_match(u64 asid) +{ + return asid_match(asid, asid_read_generation()); +} static void flush_context(void) { int i; u64 asid; + flush_generation(); + /* Update the list of reserved ASIDs and the ASID bitmap. */ set_reserved_asid_bits(); @@ -163,7 +189,7 @@ static u64 new_context(struct mm_struct *mm) { static u32 cur_idx = 1; u64 asid = atomic64_read(&mm->context.id); - u64 generation = atomic64_read(&asid_generation); + u64 generation = asid_read_generation(); if (asid != 0) { u64 newasid = asid2ctxid(ctxid2asid(asid), generation); @@ -202,14 +228,12 @@ static u64 new_context(struct mm_struct *mm) if (asid != NUM_USER_ASIDS) goto set_asid; - /* We're out of ASIDs, so increment the global generation count */ - generation = atomic64_add_return_relaxed(ASID_FIRST_VERSION, - &asid_generation); flush_context(); /* We have more ASIDs than CPUs, so this will always succeed */ asid = find_next_zero_bit(asid_map, NUM_USER_ASIDS, 1); + generation = asid_read_generation(); set_asid: __set_bit(asid, asid_map); cur_idx = asid; @@ -405,7 +429,8 @@ arch_initcall(asids_update_limit); static int asids_init(void) { asid_bits = get_cpu_asid_bits(); - atomic64_set(&asid_generation, ASID_FIRST_VERSION); + asid_generation_init(); + asid_map = bitmap_zalloc(NUM_USER_ASIDS, GFP_KERNEL); if (!asid_map) panic("Failed to allocate bitmap for %lu ASIDs\n", -- 2.27.0
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