[PATCH v3 1/7] arm64: kernel: fix style issues in sleep.S

[Ard Biesheuvel]

On 31 August 2016 at 12:05, Ard Biesheuvel <ard.biesheuvel at linaro.org> wrote:
> This fixes a number of style issues in sleep.S. No functional changes are
> intended:
> - replace absolute literal references with relative references in
>   __cpu_suspend_enter(), which executes from its virtual address
> - replace explicit lr assignment plus branch with bl in cpu_resume(), which
>   aligns it with stext() and secondary_startup()
> - don't export _cpu_resume()

Will,

Apologies, I sent out the wrong version of this patch in v3. Not
exporting _cpu_resume() breaks hibernate, so I dropped it from v2
(which is the version that Mark reviewed), but I reintroduced it by
accident.

Please let me know how you would like to proceed, i.e., put a fixup on
top, or resend.

Thanks,
Ard.


> - use adr_l for mpidr_hash reference, and fix the incorrect accompanying
>   comment, which has been out of date since commit cabe1c81ea5be983 ("arm64:
>   Change cpu_resume() to enable mmu early then access sleep_sp by va")
> - replace leading spaces with tabs, and add a bit of whitespace for
>   readability
>
> Reviewed-by: Mark Rutland <mark.rutland at arm.com>
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel at linaro.org>
> ---
>  arch/arm64/kernel/sleep.S | 21 ++++++++++----------
>  1 file changed, 10 insertions(+), 11 deletions(-)
>
> diff --git a/arch/arm64/kernel/sleep.S b/arch/arm64/kernel/sleep.S
> index 1fac020761da..6adc76bf8f91 100644
> --- a/arch/arm64/kernel/sleep.S
> +++ b/arch/arm64/kernel/sleep.S
> @@ -73,10 +73,9 @@ ENTRY(__cpu_suspend_enter)
>         str     x2, [x0, #SLEEP_STACK_DATA_SYSTEM_REGS + CPU_CTX_SP]
>
>         /* find the mpidr_hash */
> -       ldr     x1, =sleep_save_stash
> -       ldr     x1, [x1]
> +       ldr_l   x1, sleep_save_stash
>         mrs     x7, mpidr_el1
> -       ldr     x9, =mpidr_hash
> +       adr_l   x9, mpidr_hash
>         ldr     x10, [x9, #MPIDR_HASH_MASK]
>         /*
>          * Following code relies on the struct mpidr_hash
> @@ -95,15 +94,14 @@ ENTRY(__cpu_suspend_enter)
>         mov     x0, #1
>         ret
>  ENDPROC(__cpu_suspend_enter)
> -       .ltorg
>
>         .pushsection ".idmap.text", "ax"
>  ENTRY(cpu_resume)
>         bl      el2_setup               // if in EL2 drop to EL1 cleanly
> +       bl      __cpu_setup
>         /* enable the MMU early - so we can access sleep_save_stash by va */
> -       adr_l   lr, __enable_mmu        /* __cpu_setup will return here */
>         adr_l   x27, _resume_switched   /* __enable_mmu will branch here */
> -       b       __cpu_setup
> +       b       __enable_mmu
>  ENDPROC(cpu_resume)
>
>  _resume_switched:
> @@ -113,16 +111,17 @@ ENDPROC(_resume_switched)
>         .ltorg
>         .popsection
>
> -ENTRY(_cpu_resume)
> +_cpu_resume:
>         mrs     x1, mpidr_el1
> -       adrp    x8, mpidr_hash
> -       add x8, x8, #:lo12:mpidr_hash // x8 = struct mpidr_hash phys address
> -        /* retrieve mpidr_hash members to compute the hash */
> +       adr_l   x8, mpidr_hash          // x8 = struct mpidr_hash virt address
> +
> +       /* retrieve mpidr_hash members to compute the hash */
>         ldr     x2, [x8, #MPIDR_HASH_MASK]
>         ldp     w3, w4, [x8, #MPIDR_HASH_SHIFTS]
>         ldp     w5, w6, [x8, #(MPIDR_HASH_SHIFTS + 8)]
>         compute_mpidr_hash x7, x3, x4, x5, x6, x1, x2
> -        /* x7 contains hash index, let's use it to grab context pointer */
> +
> +       /* x7 contains hash index, let's use it to grab context pointer */
>         ldr_l   x0, sleep_save_stash
>         ldr     x0, [x0, x7, lsl #3]
>         add     x29, x0, #SLEEP_STACK_DATA_CALLEE_REGS
> --
> 2.7.4
>