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ARM: sleep.S: use PC-relative insn sequence for sleep_save_sp/mpidr_hash 

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.

Reviewed-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
This commit is contained in:
Ard Biesheuvel 2020-09-14 11:25:34 +03:00
parent 59d2f2827d
commit d74d2b2250
1 changed files with 5 additions and 14 deletions
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19
arch/arm/kernel/sleep.S
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@ -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