| Message ID | 1427213430-28463-2-git-send-email-ard.biesheuvel@linaro.org |
|---|---|
| State | New |
| Headers | show |
On Tue, 24 Mar 2015, Ard Biesheuvel wrote: > Move cpu_resume() to the .text section where it belongs. Change > the adr reference to sleep_save_sp to an explicit PC relative > reference so sleep_save_sp itself can remain in .data. > > This helps prevent linker failure on large kernels, as the code > in the .data section may be too far away to be in range for normal > b/bl instructions. > > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> I'm mystified. I'm sure I did convert this code away from .data at some point. Oh well... Reviewed-by: Nicolas Pitre <nico@linaro.org> > --- > arch/arm/kernel/sleep.S | 15 ++++++--------- > 1 file changed, 6 insertions(+), 9 deletions(-) > > diff --git a/arch/arm/kernel/sleep.S b/arch/arm/kernel/sleep.S > index 31041b4a3f53..fb64c96cd801 100644 > --- a/arch/arm/kernel/sleep.S > +++ b/arch/arm/kernel/sleep.S > @@ -116,14 +116,7 @@ cpu_resume_after_mmu: > ldmfd sp!, {r4 - r11, pc} > ENDPROC(cpu_resume_after_mmu) > > -/* > - * Note: Yes, part of the following code is located into the .data section. > - * This is to allow sleep_save_sp to be accessed with a relative load > - * while we can't rely on any MMU translation. We could have put > - * sleep_save_sp in the .text section as well, but some setups might > - * insist on it to be truly read-only. > - */ > - .data > + .text > .align > ENTRY(cpu_resume) > ARM_BE8(setend be) @ ensure we are in BE mode > @@ -145,6 +138,8 @@ ARM_BE8(setend be) @ ensure we are in BE mode > 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 r0, [r0, r1, lsl #2] > > @@ -156,10 +151,12 @@ THUMB( bx r3 ) > ENDPROC(cpu_resume) > > .align 2 > +_sleep_save_sp: > + .long sleep_save_sp - . > mpidr_hash_ptr: > .long mpidr_hash - . @ mpidr_hash struct offset > > + .data > .type sleep_save_sp, #object > ENTRY(sleep_save_sp) > -_sleep_save_sp: > .space SLEEP_SAVE_SP_SZ @ struct sleep_save_sp > -- > 1.8.3.2 > >
diff --git a/arch/arm/kernel/sleep.S b/arch/arm/kernel/sleep.S index 31041b4a3f53..fb64c96cd801 100644 --- a/arch/arm/kernel/sleep.S +++ b/arch/arm/kernel/sleep.S @@ -116,14 +116,7 @@ cpu_resume_after_mmu: ldmfd sp!, {r4 - r11, pc} ENDPROC(cpu_resume_after_mmu) -/* - * Note: Yes, part of the following code is located into the .data section. - * This is to allow sleep_save_sp to be accessed with a relative load - * while we can't rely on any MMU translation. We could have put - * sleep_save_sp in the .text section as well, but some setups might - * insist on it to be truly read-only. - */ - .data + .text .align ENTRY(cpu_resume) ARM_BE8(setend be) @ ensure we are in BE mode @@ -145,6 +138,8 @@ ARM_BE8(setend be) @ ensure we are in BE mode 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 r0, [r0, r1, lsl #2] @@ -156,10 +151,12 @@ THUMB( bx r3 ) ENDPROC(cpu_resume) .align 2 +_sleep_save_sp: + .long sleep_save_sp - . mpidr_hash_ptr: .long mpidr_hash - . @ mpidr_hash struct offset + .data .type sleep_save_sp, #object ENTRY(sleep_save_sp) -_sleep_save_sp: .space SLEEP_SAVE_SP_SZ @ struct sleep_save_sp
Move cpu_resume() to the .text section where it belongs. Change the adr reference to sleep_save_sp to an explicit PC relative reference so sleep_save_sp itself can remain in .data. This helps prevent linker failure on large kernels, as the code in the .data section may be too far away to be in range for normal b/bl instructions. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> --- arch/arm/kernel/sleep.S | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-)