Thread (60 messages) 60 messages, 6 authors, 2017-08-21
STALE3211d

[PATCH 20/30] ARM: kernel: use PC relative symbol references in suspend/resume code

From: Ard Biesheuvel <hidden>
Date: 2017-08-14 12:54:01
Subsystem: arm port, the rest · Maintainers: Russell King, Linus Torvalds

Replace some unnecessary absolute references with relative ones. Also,
to prepare for runtime relocation, which occurs with the caches on,
defer taking the absolute address of cpu_resume_after_mmu() until after
the MMU is enabled.

Cc: Russell King <linux@armlinux.org.uk>
Signed-off-by: Ard Biesheuvel <redacted>
---
 arch/arm/kernel/sleep.S | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)
diff --git a/arch/arm/kernel/sleep.S b/arch/arm/kernel/sleep.S
index 3026b119d3ff..9efd1c7d3552 100644
--- a/arch/arm/kernel/sleep.S
+++ b/arch/arm/kernel/sleep.S
@@ -60,18 +60,17 @@
 ENTRY(__cpu_suspend)
 	stmfd	sp!, {r4 - r11, lr}
 #ifdef MULTI_CPU
-	ldr	r10, =processor
-	ldr	r4, [r10, #CPU_SLEEP_SIZE] @ size of CPU sleep state
+	ldr_l	r4, processor + CPU_SLEEP_SIZE	@ size of CPU sleep state
 #else
-	ldr	r4, =cpu_suspend_size
+	adr_l	r4, cpu_suspend_size
 #endif
 	mov	r5, sp			@ current virtual SP
 	add	r4, r4, #12		@ Space for pgd, virt sp, phys resume fn
 	sub	sp, sp, r4		@ allocate CPU state on stack
-	ldr	r3, =sleep_save_sp
+	adr_l	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(adr_l r0, mpidr_hash)
 	ALT_UP_B(1f)
 	/* 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
@@ -100,13 +99,13 @@ ENDPROC(cpu_suspend_abort)
 	.align	5
 	.pushsection	.idmap.text,"ax"
 ENTRY(cpu_resume_mmu)
-	ldr	r3, =cpu_resume_after_mmu
 	instr_sync
 	mcr	p15, 0, r0, c1, c0, 0	@ turn on MMU, I-cache, etc
 	mrc	p15, 0, r0, c0, c0, 0	@ read id reg
 	instr_sync
 	mov	r0, r0
 	mov	r0, r0
+	ldr	r3, =cpu_resume_after_mmu
 	ret	r3			@ jump to virtual address
 ENDPROC(cpu_resume_mmu)
 	.popsection
-- 
2.11.0
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