[PATCH v3 10/15] arm64/mm: Introduce a callback to flush the local context

From: Julien Grall
Date: Wed Jul 24 2019 - 12:26:08 EST


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>
---
arch/arm64/mm/context.c | 16 +++++++++++++---
1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/mm/context.c b/arch/arm64/mm/context.c
index 5e8b381ab67f..ac10893b403c 100644
--- a/arch/arm64/mm/context.c
+++ b/arch/arm64/mm/context.c
@@ -28,6 +28,8 @@ static struct asid_info
cpumask_t flush_pending;
/* Number of ASID allocated by context (shift value) */
unsigned int ctxt_shift;
+ /* 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)
@@ -255,7 +257,7 @@ static void asid_new_context(struct asid_info *info, atomic64_t *pasid,
}

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

atomic64_set(&active_asid(info, cpu), asid);
raw_spin_unlock_irqrestore(&info->lock, flags);
@@ -287,6 +289,11 @@ asmlinkage void post_ttbr_update_workaround(void)
CONFIG_CAVIUM_ERRATUM_27456));
}

+static void asid_flush_cpu_ctxt(void)
+{
+ local_flush_tlb_all();
+}
+
/*
* Initialize the ASID allocator
*
@@ -297,10 +304,12 @@ asmlinkage void post_ttbr_update_workaround(void)
* 2.
*/
static int asid_allocator_init(struct asid_info *info,
- u32 bits, unsigned int asid_per_ctxt)
+ u32 bits, unsigned int asid_per_ctxt,
+ void (*flush_cpu_ctxt_cb)(void))
{
info->bits = bits;
info->ctxt_shift = ilog2(asid_per_ctxt);
+ info->flush_cpu_ctxt_cb = flush_cpu_ctxt_cb;
/*
* Expect allocation after rollover to fail if we don't have at least
* one more ASID than CPUs. ASID #0 is always reserved.
@@ -321,7 +330,8 @@ static int asids_init(void)
{
u32 bits = get_cpu_asid_bits();

- if (asid_allocator_init(&asid_info, bits, ASID_PER_CONTEXT))
+ if (asid_allocator_init(&asid_info, bits, ASID_PER_CONTEXT,
+ asid_flush_cpu_ctxt))
panic("Unable to initialize ASID allocator for %lu ASIDs\n",
1UL << bits);

--
2.11.0