Commit 7f153ccb authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Will Deacon
Browse files

arm64/lib: copy_page: avoid x18 register in assembler code 

Register x18 will no longer be used as a caller save register in the
future, so stop using it in the copy_page() code.

Link: https://patchwork.kernel.org/patch/9836869/


Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
[Sami: changed the offset and bias to be explicit]
Signed-off-by: default avatarSami Tolvanen <samitolvanen@google.com>
Reviewed-by: default avatarMark Rutland <mark.rutland@arm.com>
Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent e3ec6582

arch/arm64/lib/copy_page.S

+19 −19
Original line number Diff line number Diff line
@@ -34,45 +34,45 @@ alternative_else_nop_endif 
	ldp	x14, x15, [x1, #96]

	ldp	x16, x17, [x1, #112]



	mov	x18, #(PAGE_SIZE - 128)

	add	x0, x0, #256

	add	x1, x1, #128

1:

	subs	x18, x18, #128

	tst	x0, #(PAGE_SIZE - 1)



alternative_if ARM64_HAS_NO_HW_PREFETCH

	prfm	pldl1strm, [x1, #384]

alternative_else_nop_endif



	stnp	x2, x3, [x0]

	stnp	x2, x3, [x0, #-256]

	ldp	x2, x3, [x1]

	stnp	x4, x5, [x0, #16]

	stnp	x4, x5, [x0, #16 - 256]

	ldp	x4, x5, [x1, #16]

	stnp	x6, x7, [x0, #32]

	stnp	x6, x7, [x0, #32 - 256]

	ldp	x6, x7, [x1, #32]

	stnp	x8, x9, [x0, #48]

	stnp	x8, x9, [x0, #48 - 256]

	ldp	x8, x9, [x1, #48]

	stnp	x10, x11, [x0, #64]

	stnp	x10, x11, [x0, #64 - 256]

	ldp	x10, x11, [x1, #64]

	stnp	x12, x13, [x0, #80]

	stnp	x12, x13, [x0, #80 - 256]

	ldp	x12, x13, [x1, #80]

	stnp	x14, x15, [x0, #96]

	stnp	x14, x15, [x0, #96 - 256]

	ldp	x14, x15, [x1, #96]

	stnp	x16, x17, [x0, #112]

	stnp	x16, x17, [x0, #112 - 256]

	ldp	x16, x17, [x1, #112]



	add	x0, x0, #128

	add	x1, x1, #128



	b.gt	1b

	b.ne	1b



	stnp	x2, x3, [x0]

	stnp	x4, x5, [x0, #16]

	stnp	x6, x7, [x0, #32]

	stnp	x8, x9, [x0, #48]

	stnp	x10, x11, [x0, #64]

	stnp	x12, x13, [x0, #80]

	stnp	x14, x15, [x0, #96]

	stnp	x16, x17, [x0, #112]

	stnp	x2, x3, [x0, #-256]

	stnp	x4, x5, [x0, #16 - 256]

	stnp	x6, x7, [x0, #32 - 256]

	stnp	x8, x9, [x0, #48 - 256]

	stnp	x10, x11, [x0, #64 - 256]

	stnp	x12, x13, [x0, #80 - 256]

	stnp	x14, x15, [x0, #96 - 256]

	stnp	x16, x17, [x0, #112 - 256]



	ret

ENDPROC(copy_page)

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