[PATCH 09/12] ARM: sleep.S: use PC-relative insn sequence for sleep_save_sp/mpidr_hash
From: Ard Biesheuvel <ardb@kernel.org>
Date: 2020-09-14 09:59:59
Also in:
linux-efi
Subsystem:
arm port, the rest · Maintainers:
Russell King, Linus Torvalds
Replace the open coded PC relative offset calculations with adr_l and ldr_l invocations. This removes some open coded PC relative arithmetic, avoids literal pools on v7+, and slightly reduces the footprint of the code. Note that ALT_SMP() expects a single instruction so move the macro invocation after it. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> --- arch/arm/kernel/sleep.S | 19 +++++-------------- 1 file changed, 5 insertions(+), 14 deletions(-)
diff --git a/arch/arm/kernel/sleep.S b/arch/arm/kernel/sleep.S
index 5dc8b80bb693..43077e11dafd 100644
--- a/arch/arm/kernel/sleep.S
+++ b/arch/arm/kernel/sleep.S@@ -72,8 +72,9 @@ ENTRY(__cpu_suspend) ldr r3, =sleep_save_sp stmfd sp!, {r0, r1} @ save suspend func arg and pointer ldr r3, [r3, #SLEEP_SAVE_SP_VIRT] - ALT_SMP(ldr r0, =mpidr_hash) + ALT_SMP(W(nop)) @ don't use adr_l inside ALT_SMP() ALT_UP_B(1f) + adr_l r0, mpidr_hash /* This ldmia relies on the memory layout of the mpidr_hash struct */ ldmia r0, {r1, r6-r8} @ r1 = mpidr mask (r6,r7,r8) = l[0,1,2] shifts compute_mpidr_hash r0, r6, r7, r8, r2, r1
@@ -147,9 +148,8 @@ no_hyp: mov r1, #0 ALT_SMP(mrc p15, 0, r0, c0, c0, 5) ALT_UP_B(1f) - adr r2, mpidr_hash_ptr - ldr r3, [r2] - add r2, r2, r3 @ r2 = struct mpidr_hash phys address + adr_l r2, mpidr_hash @ r2 = struct mpidr_hash phys address + /* * This ldmia relies on the memory layout of the mpidr_hash * struct mpidr_hash.
@@ -157,10 +157,7 @@ no_hyp: ldmia r2, { r3-r6 } @ r3 = mpidr mask (r4,r5,r6) = l[0,1,2] shifts compute_mpidr_hash r1, r4, r5, r6, r0, r3 1: - adr r0, _sleep_save_sp - ldr r2, [r0] - add r0, r0, r2 - ldr r0, [r0, #SLEEP_SAVE_SP_PHYS] + ldr_l r0, sleep_save_sp + SLEEP_SAVE_SP_PHYS ldr r0, [r0, r1, lsl #2] @ load phys pgd, stack, resume fn
@@ -177,12 +174,6 @@ ENDPROC(cpu_resume_arm) ENDPROC(cpu_resume_no_hyp) #endif - .align 2 -_sleep_save_sp: - .long sleep_save_sp - . -mpidr_hash_ptr: - .long mpidr_hash - . @ mpidr_hash struct offset - .data .align 2 .type sleep_save_sp, #object
--
2.17.1
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