[PATCH v5 10/15] arm64: Add new asm macro copy_page
From: james.morse@arm.com (James Morse)
Date: 2016-02-16 15:49:22
Also in:
linux-pm
Subsystem:
arm64 port (aarch64 architecture), the rest · Maintainers:
Catalin Marinas, Will Deacon, Linus Torvalds
From: Geoff Levand <geoff@infradead.org> 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 <geoff@infradead.org> [Changed asm label to 9998, added commit message] Signed-off-by: James Morse <james.morse@arm.com> --- This patch comes from v13 of kexec 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 ec4e37cb3b41..f3854d9b5e31 100644
--- a/arch/arm64/include/asm/assembler.h
+++ b/arch/arm64/include/asm/assembler.h@@ -24,6 +24,7 @@ #define __ASM_ASSEMBLER_H #include <asm/asm-offsets.h> +#include <asm/page.h> #include <asm/pgtable-hwdef.h> #include <asm/ptrace.h> #include <asm/thread_info.h>
@@ -285,6 +286,24 @@ 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. */
--
2.6.2