[PATCH v4 11/16] arm64/mm: Introduce a callback to flush the local context

From: Shameer Kolothum
Date: Wed Apr 14 2021 - 07:26:16 EST


From: Julien Grall <julien.grall@xxxxxxx>

Flushing the local context will vary depending on the actual user
of the ASID allocator. Introduce a new callback to flush the local
context and move the call to flush local TLB in it.

Signed-off-by: Julien Grall <julien.grall@xxxxxxx>
Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@xxxxxxxxxx>
---
arch/arm64/mm/context.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/mm/context.c b/arch/arm64/mm/context.c
index 901472a57b5d..ee446f7535a3 100644
--- a/arch/arm64/mm/context.c
+++ b/arch/arm64/mm/context.c
@@ -32,6 +32,8 @@ static struct asid_info
unsigned long *pinned_map;
unsigned long max_pinned_asids;
unsigned long nr_pinned_asids;
+ /* Callback to locally flush the context. */
+ void (*flush_cpu_ctxt_cb)(void);
} asid_info;

#define active_asid(info, cpu) (*per_cpu_ptr((info)->active, cpu))
@@ -245,8 +247,9 @@ static void asid_new_context(struct asid_info *info, atomic64_t *pasid,
atomic64_set(pasid, asid);
}

- if (cpumask_test_and_clear_cpu(cpu, &info->flush_pending))
- local_flush_tlb_all();
+ if (cpumask_test_and_clear_cpu(cpu, &info->flush_pending) &&
+ info->flush_cpu_ctxt_cb)
+ info->flush_cpu_ctxt_cb();

atomic64_set(&active_asid(info, cpu), asid);
raw_spin_unlock_irqrestore(&info->lock, flags);
@@ -427,6 +430,11 @@ void cpu_do_switch_mm(phys_addr_t pgd_phys, struct mm_struct *mm)
post_ttbr_update_workaround();
}

+static void asid_flush_cpu_ctxt(void)
+{
+ local_flush_tlb_all();
+}
+
static int asids_update_limit(void)
{
struct asid_info *info = &asid_info;
@@ -499,6 +507,7 @@ static int asids_init(void)

info->active = &active_asids;
info->reserved = &reserved_asids;
+ info->flush_cpu_ctxt_cb = asid_flush_cpu_ctxt;

/*
* We cannot call set_reserved_asid_bits() here because CPU
--
2.17.1