On Wed, 10 Feb 2016, Geert Uytterhoeven wrote:
> CPU boot configuration writes to shmobile_boot_arg, which is located in
> the .text section, and thus should not be written to.
>
> As of commit 1d33a354bbb618ba ("ARM: shmobile: Per-CPU SMP boot / sleep
> code for SCU SoCs"), and ignoring accidental remainings,
> shmobile_boot_arg is always set to MPIDR_HWID_BITMASK by C code.
> Hence we can just hardcode this in the assembler code, and remove the
> variable, and thus also remove the need to write to this variable.
>
> Signed-off-by: Geert Uytterhoeven <geert+rene...@glider.be>
Acked-by: Nicolas Pitre <n...@linaro.org>
> ---
> v2:
> - New.
> ---
> arch/arm/mach-shmobile/common.h | 1 -
> arch/arm/mach-shmobile/headsmp.S | 8 ++------
> arch/arm/mach-shmobile/platsmp-apmu.c | 1 -
> arch/arm/mach-shmobile/platsmp-scu.c | 1 -
> 4 files changed, 2 insertions(+), 9 deletions(-)
>
> diff --git a/arch/arm/mach-shmobile/common.h b/arch/arm/mach-shmobile/common.h
> index 225c12bb3de91e76..5464b7a75e3028a7 100644
> --- a/arch/arm/mach-shmobile/common.h
> +++ b/arch/arm/mach-shmobile/common.h
> @@ -4,7 +4,6 @@
> extern void shmobile_init_delay(void);
> extern void shmobile_boot_vector(void);
> extern unsigned long shmobile_boot_fn;
> -extern unsigned long shmobile_boot_arg;
> extern unsigned long shmobile_boot_size;
> extern void shmobile_smp_boot(void);
> extern void shmobile_smp_sleep(void);
> diff --git a/arch/arm/mach-shmobile/headsmp.S
> b/arch/arm/mach-shmobile/headsmp.S
> index 4cf7f0b016b0b0fe..ede974b4fd67d8cd 100644
> --- a/arch/arm/mach-shmobile/headsmp.S
> +++ b/arch/arm/mach-shmobile/headsmp.S
> @@ -24,7 +24,6 @@
> .arm
> .align 12
> ENTRY(shmobile_boot_vector)
> - ldr r0, 2f
> ldr r1, 1f
> bx r1
>
> @@ -34,9 +33,6 @@ ENDPROC(shmobile_boot_vector)
> .globl shmobile_boot_fn
> shmobile_boot_fn:
> 1: .space 4
> - .globl shmobile_boot_arg
> -shmobile_boot_arg:
> -2: .space 4
> .globl shmobile_boot_size
> shmobile_boot_size:
> .long . - shmobile_boot_vector
> @@ -46,9 +42,9 @@ shmobile_boot_size:
> */
>
> ENTRY(shmobile_smp_boot)
> - @ r0 = MPIDR_HWID_BITMASK
> mrc p15, 0, r1, c0, c0, 5 @ r1 = MPIDR
> - and r0, r1, r0 @ r0 = cpu_logical_map() value
> + and r0, r1, #0xffffff @ MPIDR_HWID_BITMASK
> + @ r0 = cpu_logical_map() value
> mov r1, #0 @ r1 = CPU index
> adr r2, 1f
> ldmia r2, {r5, r6, r7}
> diff --git a/arch/arm/mach-shmobile/platsmp-apmu.c
> b/arch/arm/mach-shmobile/platsmp-apmu.c
> index 911884f7e28b174c..aba75c89f9c1c5eb 100644
> --- a/arch/arm/mach-shmobile/platsmp-apmu.c
> +++ b/arch/arm/mach-shmobile/platsmp-apmu.c
> @@ -123,7 +123,6 @@ void __init shmobile_smp_apmu_prepare_cpus(unsigned int
> max_cpus,
> {
> /* install boot code shared by all CPUs */
> shmobile_boot_fn = virt_to_phys(shmobile_smp_boot);
> - shmobile_boot_arg = MPIDR_HWID_BITMASK;
>
> /* perform per-cpu setup */
> apmu_parse_cfg(apmu_init_cpu, apmu_config, num);
> diff --git a/arch/arm/mach-shmobile/platsmp-scu.c
> b/arch/arm/mach-shmobile/platsmp-scu.c
> index 4c7d2caf3730f644..8d478f1da265d55e 100644
> --- a/arch/arm/mach-shmobile/platsmp-scu.c
> +++ b/arch/arm/mach-shmobile/platsmp-scu.c
> @@ -46,7 +46,6 @@ void __init shmobile_smp_scu_prepare_cpus(phys_addr_t
> scu_base_phys,
> {
> /* install boot code shared by all CPUs */
> shmobile_boot_fn = virt_to_phys(shmobile_smp_boot);
> - shmobile_boot_arg = MPIDR_HWID_BITMASK;
>
> /* enable SCU and cache coherency on booting CPU */
> shmobile_scu_base_phys = scu_base_phys;
> --
> 1.9.1
>
>
