[PATCH v2 2/2] ARM: shmobile: Remove shmobile_boot_arg

[Nicolas Pitre]

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+renesas at glider.be>

Acked-by: Nicolas Pitre <nico at 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
> 
>