[PATCH v4 03/16] arm64/mm: Move bits to asid_info
Shameer Kolothum
shameerali.kolothum.thodi at huawei.com
Wed Apr 14 12:22:59 BST 2021
From: Julien Grall <julien.grall at arm.com>
The variable bits hold information for a given ASID allocator. So move
it to the asid_info structure.
Because most of the macros were relying on bits, they are now taking an
extra parameter that is a pointer to the asid_info structure.
Signed-off-by: Julien Grall <julien.grall at arm.com>
Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi at huawei.com>
---
arch/arm64/mm/context.c | 70 +++++++++++++++++++++--------------------
1 file changed, 36 insertions(+), 34 deletions(-)
diff --git a/arch/arm64/mm/context.c b/arch/arm64/mm/context.c
index 42e011094571..1fd40a42955c 100644
--- a/arch/arm64/mm/context.c
+++ b/arch/arm64/mm/context.c
@@ -17,7 +17,6 @@
#include <asm/smp.h>
#include <asm/tlbflush.h>
-static u32 asid_bits;
static DEFINE_RAW_SPINLOCK(cpu_asid_lock);
static struct asid_info
@@ -27,6 +26,7 @@ static struct asid_info
unsigned int map_idx;
atomic64_t __percpu *active;
u64 __percpu *reserved;
+ u32 bits;
} asid_info;
#define active_asid(info, cpu) (*per_cpu_ptr((info)->active, cpu))
@@ -40,12 +40,12 @@ static unsigned long max_pinned_asids;
static unsigned long nr_pinned_asids;
static unsigned long *pinned_asid_map;
-#define ASID_MASK (~GENMASK(asid_bits - 1, 0))
-#define ASID_FIRST_VERSION (1UL << asid_bits)
+#define ASID_MASK(info) (~GENMASK((info)->bits - 1, 0))
+#define ASID_FIRST_VERSION(info) (1UL << (info)->bits)
-#define NUM_USER_ASIDS ASID_FIRST_VERSION
-#define asid2idx(asid) ((asid) & ~ASID_MASK)
-#define idx2asid(idx) asid2idx(idx)
+#define NUM_USER_ASIDS(info) ASID_FIRST_VERSION(info)
+#define asid2idx(info, asid) ((asid) & ~ASID_MASK(info))
+#define idx2asid(info, idx) asid2idx(info, idx)
/* Get the ASIDBits supported by the current CPU */
static u32 get_cpu_asid_bits(void)
@@ -74,20 +74,20 @@ void verify_cpu_asid_bits(void)
{
u32 asid = get_cpu_asid_bits();
- if (asid < asid_bits) {
+ if (asid < asid_info.bits) {
/*
* We cannot decrease the ASID size at runtime, so panic if we support
* fewer ASID bits than the boot CPU.
*/
pr_crit("CPU%d: smaller ASID size(%u) than boot CPU (%u)\n",
- smp_processor_id(), asid, asid_bits);
+ smp_processor_id(), asid, asid_info.bits);
cpu_panic_kernel();
}
}
-static void set_kpti_asid_bits(unsigned long *map)
+static void set_kpti_asid_bits(struct asid_info *info, unsigned long *map)
{
- unsigned int len = BITS_TO_LONGS(NUM_USER_ASIDS) * sizeof(unsigned long);
+ unsigned int len = BITS_TO_LONGS(NUM_USER_ASIDS(info)) * sizeof(unsigned long);
/*
* In case of KPTI kernel/user ASIDs are allocated in
* pairs, the bottom bit distinguishes the two: if it
@@ -100,15 +100,15 @@ static void set_kpti_asid_bits(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);
+ bitmap_copy(info->map, pinned_asid_map, NUM_USER_ASIDS(info));
else if (arm64_kernel_unmapped_at_el0())
- set_kpti_asid_bits(info->map);
+ set_kpti_asid_bits(info, info->map);
else
- bitmap_clear(info->map, 0, NUM_USER_ASIDS);
+ bitmap_clear(info->map, 0, NUM_USER_ASIDS(info));
}
#define asid_gen_match(asid, info) \
- (!(((asid) ^ atomic64_read(&(info)->generation)) >> asid_bits))
+ (!(((asid) ^ atomic64_read(&(info)->generation)) >> info->bits))
static void flush_context(struct asid_info *info)
{
@@ -129,7 +129,7 @@ static void flush_context(struct asid_info *info)
*/
if (asid == 0)
asid = reserved_asid(info, i);
- __set_bit(asid2idx(asid), info->map);
+ __set_bit(asid2idx(info, asid), info->map);
reserved_asid(info, i) = asid;
}
@@ -171,7 +171,7 @@ static u64 new_context(struct asid_info *info, struct mm_struct *mm)
u64 generation = atomic64_read(&info->generation);
if (asid != 0) {
- u64 newasid = generation | (asid & ~ASID_MASK);
+ u64 newasid = generation | (asid & ~ASID_MASK(info));
/*
* If our current ASID was active during a rollover, we
@@ -192,7 +192,7 @@ static u64 new_context(struct asid_info *info, struct mm_struct *mm)
* We had a valid ASID in a previous life, so try to re-use
* it if possible.
*/
- if (!__test_and_set_bit(asid2idx(asid), info->map))
+ if (!__test_and_set_bit(asid2idx(info, asid), info->map))
return newasid;
}
@@ -203,22 +203,22 @@ static u64 new_context(struct asid_info *info, struct mm_struct *mm)
* 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->map_idx);
- if (asid != NUM_USER_ASIDS)
+ asid = find_next_zero_bit(info->map, NUM_USER_ASIDS(info), info->map_idx);
+ if (asid != NUM_USER_ASIDS(info))
goto set_asid;
/* We're out of ASIDs, so increment the global generation count */
- generation = atomic64_add_return_relaxed(ASID_FIRST_VERSION,
+ generation = atomic64_add_return_relaxed(ASID_FIRST_VERSION(info),
&info->generation);
flush_context(info);
/* We have more ASIDs than CPUs, so this will always succeed */
- asid = find_next_zero_bit(info->map, NUM_USER_ASIDS, 1);
+ asid = find_next_zero_bit(info->map, NUM_USER_ASIDS(info), 1);
set_asid:
__set_bit(asid, info->map);
info->map_idx = asid;
- return idx2asid(asid) | generation;
+ return idx2asid(info, asid) | generation;
}
void check_and_switch_context(struct mm_struct *mm)
@@ -311,13 +311,13 @@ unsigned long arm64_mm_context_get(struct mm_struct *mm)
}
nr_pinned_asids++;
- __set_bit(asid2idx(asid), pinned_asid_map);
+ __set_bit(asid2idx(info, asid), pinned_asid_map);
refcount_set(&mm->context.pinned, 1);
out_unlock:
raw_spin_unlock_irqrestore(&cpu_asid_lock, flags);
- asid &= ~ASID_MASK;
+ asid &= ~ASID_MASK(info);
/* Set the equivalent of USER_ASID_BIT */
if (asid && arm64_kernel_unmapped_at_el0())
@@ -330,6 +330,7 @@ EXPORT_SYMBOL_GPL(arm64_mm_context_get);
void arm64_mm_context_put(struct mm_struct *mm)
{
unsigned long flags;
+ struct asid_info *info = &asid_info;
u64 asid = atomic64_read(&mm->context.id);
if (!pinned_asid_map)
@@ -338,7 +339,7 @@ void arm64_mm_context_put(struct mm_struct *mm)
raw_spin_lock_irqsave(&cpu_asid_lock, flags);
if (refcount_dec_and_test(&mm->context.pinned)) {
- __clear_bit(asid2idx(asid), pinned_asid_map);
+ __clear_bit(asid2idx(info, asid), pinned_asid_map);
nr_pinned_asids--;
}
@@ -384,12 +385,13 @@ void cpu_do_switch_mm(phys_addr_t pgd_phys, struct mm_struct *mm)
static int asids_update_limit(void)
{
- unsigned long num_available_asids = NUM_USER_ASIDS;
+ struct asid_info *info = &asid_info;
+ unsigned long num_available_asids = NUM_USER_ASIDS(info);
if (arm64_kernel_unmapped_at_el0()) {
num_available_asids /= 2;
if (pinned_asid_map)
- set_kpti_asid_bits(pinned_asid_map);
+ set_kpti_asid_bits(info, pinned_asid_map);
}
/*
* Expect allocation after rollover to fail if we don't have at least
@@ -413,19 +415,19 @@ static int asids_init(void)
{
struct asid_info *info = &asid_info;
- asid_bits = get_cpu_asid_bits();
- atomic64_set(&info->generation, ASID_FIRST_VERSION);
- info->map = kcalloc(BITS_TO_LONGS(NUM_USER_ASIDS), sizeof(*info->map),
- GFP_KERNEL);
+ info->bits = get_cpu_asid_bits();
+ atomic64_set(&info->generation, ASID_FIRST_VERSION(info));
+ info->map = kcalloc(BITS_TO_LONGS(NUM_USER_ASIDS(info)),
+ sizeof(*info->map), GFP_KERNEL);
if (!info->map)
panic("Failed to allocate bitmap for %lu ASIDs\n",
- NUM_USER_ASIDS);
+ NUM_USER_ASIDS(info));
info->map_idx = 1;
info->active = &active_asids;
info->reserved = &reserved_asids;
- pinned_asid_map = kcalloc(BITS_TO_LONGS(NUM_USER_ASIDS),
+ pinned_asid_map = kcalloc(BITS_TO_LONGS(NUM_USER_ASIDS(info)),
sizeof(*pinned_asid_map), GFP_KERNEL);
nr_pinned_asids = 0;
@@ -435,7 +437,7 @@ static int asids_init(void)
* and reserve kernel ASID's from beginning.
*/
if (IS_ENABLED(CONFIG_UNMAP_KERNEL_AT_EL0))
- set_kpti_asid_bits(info->map);
+ set_kpti_asid_bits(info, info->map);
return 0;
}
early_initcall(asids_init);
--
2.17.1
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