From mboxrd@z Thu Jan 1 00:00:00 1970 From: james.morse@arm.com (James Morse) Date: Wed, 20 Jan 2016 14:01:44 +0000 Subject: [PATCH 03/19] arm64: Add new asm macro copy_page In-Reply-To: References: Message-ID: <569F9348.2000100@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Geoff, On 15/01/16 19:18, Geoff Levand wrote: Can I donate a commit message: 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(). Convert copy_page() to a macro, so that it can be inlined in these situations. > Signed-off-by: Geoff Levand > --- > 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 21979a4..c47a623 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 > @@ -240,6 +241,24 @@ 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 > +1: ldp \t1, \t2, [\src] Using '1' as a label here means callers can't jump back over it using the same label. The convention with USER() and alternatives is to use unlikely values like '9999'. > + 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 1b > + .endm It may be worth updating lib/copy_page.S to use this macro. I will fix the code in hibernate to use this! Thanks, James