Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 5003dbde authored by Geoff Levand's avatar Geoff Levand Committed by Will Deacon
Browse files

arm64: Add new asm macro copy_page 



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: default avatarGeoff Levand <geoff@infradead.org>
[Changed asm label to 9998, added commit message]
Signed-off-by: default avatarJames Morse <james.morse@arm.com>
Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent 28c72583

arch/arm64/include/asm/assembler.h

+19 −0
Original line number Diff line number Diff line
@@ -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>
@@ -279,6 +280,24 @@ lr .req x30 // link register 
9000:

	.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.