[PATCH v4 06/16] arm64/mm: Introduce NUM_CTXT_ASIDS

From: Shameer Kolothum
Date: Wed Apr 14 2021 - 07:25:48 EST


From: Julien Grall <julien.grall@xxxxxxx>

At the moment ASID_FIRST_VERSION is used to know the number of ASIDs
supported. As we are going to move the ASID allocator to a separate file,
it would be better to use a different name for external users.

Signed-off-by: Julien Grall <julien.grall@xxxxxxx>
Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@xxxxxxxxxx>
---
v3-->v4
-Dropped patch #6, but retained the name NUM_CTXT_ASIDS.

---
arch/arm64/mm/context.c | 24 ++++++++++++------------
1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/arch/arm64/mm/context.c b/arch/arm64/mm/context.c
index 628304e0d3b1..0f11d7c7f6a3 100644
--- a/arch/arm64/mm/context.c
+++ b/arch/arm64/mm/context.c
@@ -41,9 +41,9 @@ static unsigned long nr_pinned_asids;
static unsigned long *pinned_asid_map;

#define ASID_MASK(info) (~GENMASK((info)->bits - 1, 0))
-#define ASID_FIRST_VERSION(info) (1UL << (info)->bits)
+#define NUM_CTXT_ASIDS(info) (1UL << ((info)->bits))
+#define ASID_FIRST_VERSION(info) NUM_CTXT_ASIDS(info)

-#define NUM_USER_ASIDS(info) ASID_FIRST_VERSION(info)
#define asid2idx(info, asid) ((asid) & ~ASID_MASK(info))
#define idx2asid(info, idx) asid2idx(info, idx)

@@ -87,7 +87,7 @@ void verify_cpu_asid_bits(void)

static void set_kpti_asid_bits(struct asid_info *info, unsigned long *map)
{
- unsigned int len = BITS_TO_LONGS(NUM_USER_ASIDS(info)) * sizeof(unsigned long);
+ unsigned int len = BITS_TO_LONGS(NUM_CTXT_ASIDS(info)) * sizeof(unsigned long);
/*
* In case of KPTI kernel/user ASIDs are allocated in
* pairs, the bottom bit distinguishes the two: if it
@@ -100,11 +100,11 @@ static void set_kpti_asid_bits(struct asid_info *info, unsigned long *map)
static void set_reserved_asid_bits(struct asid_info *info)
{
if (pinned_asid_map)
- bitmap_copy(info->map, pinned_asid_map, NUM_USER_ASIDS(info));
+ bitmap_copy(info->map, pinned_asid_map, NUM_CTXT_ASIDS(info));
else if (arm64_kernel_unmapped_at_el0())
set_kpti_asid_bits(info, info->map);
else
- bitmap_clear(info->map, 0, NUM_USER_ASIDS(info));
+ bitmap_clear(info->map, 0, NUM_CTXT_ASIDS(info));
}

#define asid_gen_match(asid, info) \
@@ -204,8 +204,8 @@ static u64 new_context(struct asid_info *info, atomic64_t *pasid,
* a reserved TTBR0 for the init_mm and we allocate ASIDs in even/odd
* pairs.
*/
- asid = find_next_zero_bit(info->map, NUM_USER_ASIDS(info), info->map_idx);
- if (asid != NUM_USER_ASIDS(info))
+ asid = find_next_zero_bit(info->map, NUM_CTXT_ASIDS(info), info->map_idx);
+ if (asid != NUM_CTXT_ASIDS(info))
goto set_asid;

/* We're out of ASIDs, so increment the global generation count */
@@ -214,7 +214,7 @@ static u64 new_context(struct asid_info *info, atomic64_t *pasid,
flush_context(info);

/* We have more ASIDs than CPUs, so this will always succeed */
- asid = find_next_zero_bit(info->map, NUM_USER_ASIDS(info), 1);
+ asid = find_next_zero_bit(info->map, NUM_CTXT_ASIDS(info), 1);

set_asid:
__set_bit(asid, info->map);
@@ -387,7 +387,7 @@ void cpu_do_switch_mm(phys_addr_t pgd_phys, struct mm_struct *mm)
static int asids_update_limit(void)
{
struct asid_info *info = &asid_info;
- unsigned long num_available_asids = NUM_USER_ASIDS(info);
+ unsigned long num_available_asids = NUM_CTXT_ASIDS(info);

if (arm64_kernel_unmapped_at_el0()) {
num_available_asids /= 2;
@@ -418,18 +418,18 @@ static int asids_init(void)

info->bits = get_cpu_asid_bits();
atomic64_set(&info->generation, ASID_FIRST_VERSION(info));
- info->map = kcalloc(BITS_TO_LONGS(NUM_USER_ASIDS(info)),
+ info->map = kcalloc(BITS_TO_LONGS(NUM_CTXT_ASIDS(info)),
sizeof(*info->map), GFP_KERNEL);
if (!info->map)
panic("Failed to allocate bitmap for %lu ASIDs\n",
- NUM_USER_ASIDS(info));
+ NUM_CTXT_ASIDS(info));

info->map_idx = 1;
info->active = &active_asids;
info->reserved = &reserved_asids;
raw_spin_lock_init(&info->lock);

- pinned_asid_map = kcalloc(BITS_TO_LONGS(NUM_USER_ASIDS(info)),
+ pinned_asid_map = kcalloc(BITS_TO_LONGS(NUM_CTXT_ASIDS(info)),
sizeof(*pinned_asid_map), GFP_KERNEL);
nr_pinned_asids = 0;

--
2.17.1