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memclear: non-temporal memory clean (arm64)

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Change-Id: I8f80ff20e98bc01088450282e1790c27c67c16eb
This commit is contained in:
Balazs Gerofi
2020-05-27 16:15:55 +09:00
committed by Masamichi Takagi
parent 201f5ce500
commit e056cb799f
3 changed files with 53 additions and 9 deletions
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9
arch/arm64/kernel/include/arch-string.h
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@ -10,4 +10,13 @@ extern void *__inline_memcpy(void *to, const void *from, size_t t);
extern void *__inline_memset(void *s, unsigned long c, size_t count);
#define ARCH_MEMCLEAR
extern void __memclear(void *addr, unsigned long len, void *tmp);
inline static void memclear(void *addr, unsigned long len)
{
uint64_t q0q1[4];
__memclear(addr, len, (void *)&q0q1);
}
#endif /* __HEADER_ARM64_COMMON_ARCH_TIMER_H */

38
arch/arm64/kernel/memset.S
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@ -218,3 +218,41 @@ ENTRY(__inline_memset)
ret
ENDPIPROC(__inline_memset)
ENDPROC(____inline_memset)
/*
* Non-temporal vector memory clear
*
* Parameters:
* x0 - buf (assumed to be aligned to page size)
* x1 - n (assumed to be at least page size)
*/
ENTRY(__memclear)
stp q0, q1, [x2] /* Preserve two 128 bit vector regs */
eor v0.16B, v0.16B, v0.16B
eor v1.16B, v1.16B, v1.16B
1:
stnp q0, q1, [x0, #32 * 0]
stnp q0, q1, [x0, #32 * 1]
stnp q0, q1, [x0, #32 * 2]
stnp q0, q1, [x0, #32 * 3]
stnp q0, q1, [x0, #32 * 4]
stnp q0, q1, [x0, #32 * 5]
stnp q0, q1, [x0, #32 * 6]
stnp q0, q1, [x0, #32 * 7]
stnp q0, q1, [x0, #32 * 8]
stnp q0, q1, [x0, #32 * 9]
stnp q0, q1, [x0, #32 * 10]
stnp q0, q1, [x0, #32 * 11]
stnp q0, q1, [x0, #32 * 12]
stnp q0, q1, [x0, #32 * 13]
stnp q0, q1, [x0, #32 * 14]
stnp q0, q1, [x0, #32 * 15]
add x0, x0, #512
subs x1, x1, #512
cmp x1, #0
b.ne 1b
ldp q0, q1, [x2] /* Restore vector regs */
ret
ENDPROC(__memclear)

15
kernel/process.c
View File

@ -1466,17 +1466,14 @@ int add_process_memory_range(struct process_vm *vm,
/* Clear content! */
if (phys != NOPHYS && !(flag & (VR_REMOTE | VR_DEMAND_PAGING))
&& ((flag & VR_PROT_MASK) != VR_PROT_NONE)) {
#if 1
memset((void *)phys_to_virt(phys), 0, end - start);
if (!zero_at_free) {
#ifdef ARCH_MEMCLEAR
memclear((void *)phys_to_virt(phys), end - start);
#else
if (end - start < (1024*1024)) {
memset((void*)phys_to_virt(phys), 0, end - start);
}
else {
memset_smp(&cpu_local_var(current)->cpu_set,
(void *)phys_to_virt(phys), 0, end - start);
}
memset((void *)phys_to_virt(phys), 0, end - start);
#endif
}
}
/* Return range object if requested */