The commit 0c8ea531b774 ("arm64: mm: Allocate ASIDs in pairs") introduce
the asid2idx and idx2asid macro, but these macros are not really useful
after the commit f88f42f853a8 ("arm64: context: Free up kernel ASIDs if
KPTI is not in use").
The code "(asid & ~ASID_MASK)" can be instead by a macro, which is the
same code with asid2idx(). So rename it to ctxid2asid() for a better
understanding.
Also we add asid2ctxid() macro, the contextid can be generated based on
the asid and generation through this macro.
Signed-off-by: Yunfeng Ye <[email protected]>
Reviewed-by: Kefeng Wang <[email protected]>
---
v2 -> v3:
- Add "Signed-off-by" and "Reviewed-by"
v1 -> v2:
- Split the patch and rename asid2idx() to ctxid2asid()
arch/arm64/mm/context.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)
diff --git a/arch/arm64/mm/context.c b/arch/arm64/mm/context.c
index cd72576ae2b7..bbc2708fe928 100644
--- a/arch/arm64/mm/context.c
+++ b/arch/arm64/mm/context.c
@@ -35,8 +35,8 @@ static unsigned long *pinned_asid_map;
#define ASID_FIRST_VERSION (1UL << asid_bits)
#define NUM_USER_ASIDS ASID_FIRST_VERSION
-#define asid2idx(asid) ((asid) & ~ASID_MASK)
-#define idx2asid(idx) asid2idx(idx)
+#define ctxid2asid(asid) ((asid) & ~ASID_MASK)
+#define asid2ctxid(asid, genid) ((asid) | (genid))
/* Get the ASIDBits supported by the current CPU */
static u32 get_cpu_asid_bits(void)
@@ -120,7 +120,7 @@ static void flush_context(void)
*/
if (asid == 0)
asid = per_cpu(reserved_asids, i);
- __set_bit(asid2idx(asid), asid_map);
+ __set_bit(ctxid2asid(asid), asid_map);
per_cpu(reserved_asids, i) = asid;
}
@@ -162,7 +162,7 @@ static u64 new_context(struct mm_struct *mm)
u64 generation = atomic64_read(&asid_generation);
if (asid != 0) {
- u64 newasid = generation | (asid & ~ASID_MASK);
+ u64 newasid = asid2ctxid(ctxid2asid(asid), generation);
/*
* If our current ASID was active during a rollover, we
@@ -183,7 +183,7 @@ static u64 new_context(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), asid_map))
+ if (!__test_and_set_bit(ctxid2asid(asid), asid_map))
return newasid;
}
@@ -209,7 +209,7 @@ static u64 new_context(struct mm_struct *mm)
set_asid:
__set_bit(asid, asid_map);
cur_idx = asid;
- return idx2asid(asid) | generation;
+ return asid2ctxid(asid, generation);
}
void check_and_switch_context(struct mm_struct *mm)
@@ -300,13 +300,13 @@ unsigned long arm64_mm_context_get(struct mm_struct *mm)
}
nr_pinned_asids++;
- __set_bit(asid2idx(asid), pinned_asid_map);
+ __set_bit(ctxid2asid(asid), pinned_asid_map);
refcount_set(&mm->context.pinned, 1);
out_unlock:
raw_spin_unlock_irqrestore(&cpu_asid_lock, flags);
- asid &= ~ASID_MASK;
+ asid = ctxid2asid(asid);
/* Set the equivalent of USER_ASID_BIT */
if (asid && arm64_kernel_unmapped_at_el0())
@@ -327,7 +327,7 @@ 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(ctxid2asid(asid), pinned_asid_map);
nr_pinned_asids--;
}
--
2.27.0
The commit 95b54c3e4c92 ("KVM: arm64: Add feature register flag
definitions") introduce the ID_AA64MMFR0_ASID_8 and ID_AA64MMFR0_ASID_16
macros.
We can use these macros for cheanup in get_cpu_asid_bits().
No functional change.
Signed-off-by: Yunfeng Ye <[email protected]>
Reviewed-by: Kefeng Wang <[email protected]>
---
v2 -> v3:
- Delete the first blank line
- Add "Signed-off-by" and "Reviewed-by"
v1 -> v2:
- Split the patch
arch/arm64/mm/context.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/mm/context.c b/arch/arm64/mm/context.c
index bbc2708fe928..b8b4cf0bcf39 100644
--- a/arch/arm64/mm/context.c
+++ b/arch/arm64/mm/context.c
@@ -50,10 +50,10 @@ static u32 get_cpu_asid_bits(void)
pr_warn("CPU%d: Unknown ASID size (%d); assuming 8-bit\n",
smp_processor_id(), fld);
fallthrough;
- case 0:
+ case ID_AA64MMFR0_ASID_8:
asid = 8;
break;
- case 2:
+ case ID_AA64MMFR0_ASID_16:
asid = 16;
}
--
2.27.0
On Thu, 9 Dec 2021 09:42:25 +0800, Yunfeng Ye wrote:
> The commit 0c8ea531b774 ("arm64: mm: Allocate ASIDs in pairs") introduce
> the asid2idx and idx2asid macro, but these macros are not really useful
> after the commit f88f42f853a8 ("arm64: context: Free up kernel ASIDs if
> KPTI is not in use").
>
> The code "(asid & ~ASID_MASK)" can be instead by a macro, which is the
> same code with asid2idx(). So rename it to ctxid2asid() for a better
> understanding.
>
> [...]
Applied to arm64 (for-next/misc), thanks!
[1/2] arm64: mm: Rename asid2idx() to ctxid2asid()
https://git.kernel.org/arm64/c/a3a5b763410c
[2/2] arm64: mm: Use asid feature macro for cheanup
https://git.kernel.org/arm64/c/386a74677be1
--
Catalin