From: Julien Grall <julien.grall@xxxxxxx> The variables active_asids and reserved_asids hold information for a given ASID allocator. So move them to the structure asid_info. At the same time, introduce wrappers to access the active and reserved ASIDs to make the code clearer. Signed-off-by: Julien Grall <julien.grall@xxxxxxx> Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@xxxxxxxxxx> --- v3-->v4 keep the this_cpu_ptr in fastpath. See c4885bbb3afe("arm64/mm: save memory access in check_and_switch_context() fast switch path") --- arch/arm64/mm/context.c | 32 ++++++++++++++++++++------------ 1 file changed, 20 insertions(+), 12 deletions(-) diff --git a/arch/arm64/mm/context.c b/arch/arm64/mm/context.c index 783f8bdb91ee..42e011094571 100644 --- a/arch/arm64/mm/context.c +++ b/arch/arm64/mm/context.c @@ -25,8 +25,13 @@ static struct asid_info atomic64_t generation; unsigned long *map; unsigned int map_idx; + atomic64_t __percpu *active; + u64 __percpu *reserved; } asid_info; +#define active_asid(info, cpu) (*per_cpu_ptr((info)->active, cpu)) +#define reserved_asid(info, cpu) (*per_cpu_ptr((info)->reserved, cpu)) + static DEFINE_PER_CPU(atomic64_t, active_asids); static DEFINE_PER_CPU(u64, reserved_asids); static cpumask_t tlb_flush_pending; @@ -114,7 +119,7 @@ static void flush_context(struct asid_info *info) set_reserved_asid_bits(info); for_each_possible_cpu(i) { - asid = atomic64_xchg_relaxed(&per_cpu(active_asids, i), 0); + asid = atomic64_xchg_relaxed(&active_asid(info, i), 0); /* * If this CPU has already been through a * rollover, but hasn't run another task in @@ -123,9 +128,9 @@ static void flush_context(struct asid_info *info) * the process it is still running. */ if (asid == 0) - asid = per_cpu(reserved_asids, i); + asid = reserved_asid(info, i); __set_bit(asid2idx(asid), info->map); - per_cpu(reserved_asids, i) = asid; + reserved_asid(info, i) = asid; } /* @@ -135,7 +140,8 @@ static void flush_context(struct asid_info *info) cpumask_setall(&tlb_flush_pending); } -static bool check_update_reserved_asid(u64 asid, u64 newasid) +static bool check_update_reserved_asid(struct asid_info *info, u64 asid, + u64 newasid) { int cpu; bool hit = false; @@ -150,9 +156,9 @@ static bool check_update_reserved_asid(u64 asid, u64 newasid) * generation. */ for_each_possible_cpu(cpu) { - if (per_cpu(reserved_asids, cpu) == asid) { + if (reserved_asid(info, cpu) == asid) { hit = true; - per_cpu(reserved_asids, cpu) = newasid; + reserved_asid(info, cpu) = newasid; } } @@ -171,7 +177,7 @@ static u64 new_context(struct asid_info *info, struct mm_struct *mm) * If our current ASID was active during a rollover, we * can continue to use it and this was just a false alarm. */ - if (check_update_reserved_asid(asid, newasid)) + if (check_update_reserved_asid(info, asid, newasid)) return newasid; /* @@ -229,8 +235,8 @@ void check_and_switch_context(struct mm_struct *mm) /* * The memory ordering here is subtle. - * If our active_asids is non-zero and the ASID matches the current - * generation, then we update the active_asids entry with a relaxed + * If our active_asid is non-zero and the ASID matches the current + * generation, then we update the active_asid entry with a relaxed * cmpxchg. Racing with a concurrent rollover means that either: * * - We get a zero back from the cmpxchg and end up waiting on the @@ -241,9 +247,9 @@ void check_and_switch_context(struct mm_struct *mm) * relaxed xchg in flush_context will treat us as reserved * because atomic RmWs are totally ordered for a given location. */ - old_active_asid = atomic64_read(this_cpu_ptr(&active_asids)); + old_active_asid = atomic64_read(this_cpu_ptr(info->active)); if (old_active_asid && asid_gen_match(asid, info) && - atomic64_cmpxchg_relaxed(this_cpu_ptr(&active_asids), + atomic64_cmpxchg_relaxed(this_cpu_ptr(info->active), old_active_asid, asid)) goto switch_mm_fastpath; @@ -259,7 +265,7 @@ void check_and_switch_context(struct mm_struct *mm) if (cpumask_test_and_clear_cpu(cpu, &tlb_flush_pending)) local_flush_tlb_all(); - atomic64_set(this_cpu_ptr(&active_asids), asid); + atomic64_set(&active_asid(info, cpu), asid); raw_spin_unlock_irqrestore(&cpu_asid_lock, flags); switch_mm_fastpath: @@ -416,6 +422,8 @@ static int asids_init(void) NUM_USER_ASIDS); info->map_idx = 1; + info->active = &active_asids; + info->reserved = &reserved_asids; pinned_asid_map = kcalloc(BITS_TO_LONGS(NUM_USER_ASIDS), sizeof(*pinned_asid_map), GFP_KERNEL); -- 2.17.1 _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm