From 8ea41b11ef746e1ac97f8c90911e5c61f8bd5cc0 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Sat, 15 Jul 2017 17:23:13 +0100 Subject: arm64: assembler: allow adr_this_cpu to use the stack pointer Given that adr_this_cpu already requires a temp register in addition to the destination register, tweak the instruction sequence so that sp may be used as well. This will simplify switching to per-cpu stacks in subsequent patches. While this limits the range of adr_this_cpu, to +/-4GiB, we don't currently use adr_this_cpu in modules, and this is not problematic for the main kernel image. Signed-off-by: Ard Biesheuvel [Mark: add more commit text] Signed-off-by: Mark Rutland Reviewed-by: Will Deacon Tested-by: Laura Abbott Cc: Catalin Marinas Cc: James Morse --- arch/arm64/include/asm/assembler.h | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h index 610a42018241..2f2bd5192b5e 100644 --- a/arch/arm64/include/asm/assembler.h +++ b/arch/arm64/include/asm/assembler.h @@ -230,12 +230,18 @@ lr .req x30 // link register .endm /* - * @dst: Result of per_cpu(sym, smp_processor_id()) + * @dst: Result of per_cpu(sym, smp_processor_id()), can be SP for + * non-module code * @sym: The name of the per-cpu variable * @tmp: scratch register */ .macro adr_this_cpu, dst, sym, tmp +#ifndef MODULE + adrp \tmp, \sym + add \dst, \tmp, #:lo12:\sym +#else adr_l \dst, \sym +#endif mrs \tmp, tpidr_el1 add \dst, \dst, \tmp .endm -- cgit v1.2.3-59-g8ed1b