From mboxrd@z Thu Jan 1 00:00:00 1970 From: james.morse@arm.com (James Morse) Date: Mon, 29 Feb 2016 17:20:19 +0000 Subject: [PATCH v6 10/14] arm64: Add new asm macro copy_page In-Reply-To: <1456766423-1554-1-git-send-email-james.morse@arm.com> References: <1456766423-1554-1-git-send-email-james.morse@arm.com> Message-ID: <1456766423-1554-11-git-send-email-james.morse@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org From: Geoff Levand Kexec and hibernate need to copy pages of memory, but may not have all of the kernel mapped, and are unable to call copy_page(). Add a simplistic copy_page() macro, that can be inlined in these situations. lib/copy_page.S provides a bigger better version, but uses more registers. Signed-off-by: Geoff Levand [Changed asm label to 9998, added commit message] Signed-off-by: James Morse --- arch/arm64/include/asm/assembler.h | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h index c72474c2d4dc..a04fd7a9c102 100644 --- a/arch/arm64/include/asm/assembler.h +++ b/arch/arm64/include/asm/assembler.h @@ -24,6 +24,7 @@ #define __ASM_ASSEMBLER_H #include +#include #include #include #include @@ -292,6 +293,24 @@ lr .req x30 // link register .endm /* + * copy_page - copy src to dest using temp registers t1-t8 + */ + .macro copy_page dest:req src:req t1:req t2:req t3:req t4:req t5:req t6:req t7:req t8:req +9998: ldp \t1, \t2, [\src] + ldp \t3, \t4, [\src, #16] + ldp \t5, \t6, [\src, #32] + ldp \t7, \t8, [\src, #48] + add \src, \src, #64 + stnp \t1, \t2, [\dest] + stnp \t3, \t4, [\dest, #16] + stnp \t5, \t6, [\dest, #32] + stnp \t7, \t8, [\dest, #48] + add \dest, \dest, #64 + tst \src, #(PAGE_SIZE - 1) + b.ne 9998b + .endm + +/* * Annotate a function as position independent, i.e., safe to be called before * the kernel virtual mapping is activated. */ -- 2.7.0