mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2025-04-12 06:49:52 +00:00
Code Issues Packages Projects Releases Wiki Activity

arm64: lib: Use MOPS for copy_page() and clear_page()

Browse Source 
Similarly to what was done to the memcpy() routines, make copy_page()
and clear_page() also use the Armv8.8 FEAT_MOPS instructions.

Note: For copy_page() this uses the CPY* instructions instead of CPYF*
as CPYF* doesn't allow src and dst to be equal. It's not clear if
copy_page() needs to allow equal src and dst but it has worked so far
with the current implementation and there is no documentation forbidding
it.

Note, the unoptimized version of copy_page() in assembler.h is left as
it is.

Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com>
Link: https://lore.kernel.org/r/20240930161051.3777828-6-kristina.martsenko@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This commit is contained in:
Kristina Martsenko 2024-09-30 17:10:51 +01:00 committed by Catalin Marinas
parent 836ed3c4e4
commit ce6b5ff5f1
2 changed files with 26 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
arch/arm64/lib/clear_page.S
View File

@ -15,6 +15,19 @@
* x0 - dest
*/
SYM_FUNC_START(__pi_clear_page)
#ifdef CONFIG_AS_HAS_MOPS
.arch_extension mops
alternative_if_not ARM64_HAS_MOPS
b .Lno_mops
alternative_else_nop_endif
mov x1, #PAGE_SIZE
setpn [x0]!, x1!, xzr
setmn [x0]!, x1!, xzr
seten [x0]!, x1!, xzr
ret
.Lno_mops:
#endif
mrs x1, dczid_el0
tbnz x1, #4, 2f /* Branch if DC ZVA is prohibited */
and w1, w1, #0xf

13
arch/arm64/lib/copy_page.S
View File

@ -18,6 +18,19 @@
* x1 - src
*/
SYM_FUNC_START(__pi_copy_page)
#ifdef CONFIG_AS_HAS_MOPS
.arch_extension mops
alternative_if_not ARM64_HAS_MOPS
b .Lno_mops
alternative_else_nop_endif
mov x2, #PAGE_SIZE
cpypwn [x0]!, [x1]!, x2!
cpymwn [x0]!, [x1]!, x2!
cpyewn [x0]!, [x1]!, x2!
ret
.Lno_mops:
#endif
ldp x2, x3, [x1]
ldp x4, x5, [x1, #16]
ldp x6, x7, [x1, #32]