[U-Boot] [PATCH 13/15] ARM: PSCI: Add helper functions to access per-CPU target PC storage

[Hongbo Zhang]

On Sun, Jun 19, 2016 at 12:38 PM, Chen-Yu Tsai <wens at csie.org> wrote:
> Now that we have a data section, add helper functions to save and fetch
> per-CPU target PC.
>
> Signed-off-by: Chen-Yu Tsai <wens at csie.org>
> ---
>  arch/arm/cpu/armv7/Makefile      |  1 +
>  arch/arm/cpu/armv7/psci-common.c | 39 +++++++++++++++++++++++++++++++++++++++
>  arch/arm/include/asm/psci.h      |  4 ++++
>  3 files changed, 44 insertions(+)
>  create mode 100644 arch/arm/cpu/armv7/psci-common.c
>
> diff --git a/arch/arm/cpu/armv7/Makefile b/arch/arm/cpu/armv7/Makefile
> index 328c4b10e976..730b59986a01 100644
> --- a/arch/arm/cpu/armv7/Makefile
> +++ b/arch/arm/cpu/armv7/Makefile
> @@ -26,6 +26,7 @@ endif
>
>  ifneq ($(CONFIG_ARMV7_PSCI),)
>  obj-y  += psci.o
> +obj-y  += psci-common.o

The Makefile was updated, this patch doen't apply today, but only a
minor change is needed.

>  endif
>
>  obj-$(CONFIG_IPROC) += iproc-common/
> diff --git a/arch/arm/cpu/armv7/psci-common.c b/arch/arm/cpu/armv7/psci-common.c
> new file mode 100644
> index 000000000000..d14b6937473f
> --- /dev/null
> +++ b/arch/arm/cpu/armv7/psci-common.c
> @@ -0,0 +1,39 @@
> +/*
> + * Common PSCI functions
> + *
> + * Copyright (C) 2016 Chen-Yu Tsai
> + * Author: Chen-Yu Tsai <wens at csie.org>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program.  If not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#include <config.h>
> +#include <asm/armv7.h>
> +#include <asm/macro.h>
> +#include <asm/psci.h>
> +#include <asm/secure.h>
> +#include <linux/linkage.h>
> +
> +static u32 psci_target_pc[CONFIG_ARMV7_PSCI_NR_CPUS] __secure_data = { 0 };
> +
> +void __secure psci_save_target_pc(int cpu, u32 pc)
> +{
> +       psci_target_pc[cpu] = pc;
> +       DSB;
> +}
> +
> +u32 __secure psci_get_target_pc(int cpu)
> +{
> +       return psci_target_pc[cpu];
> +}
> +
> diff --git a/arch/arm/include/asm/psci.h b/arch/arm/include/asm/psci.h
> index dab576997654..a0da02300700 100644
> --- a/arch/arm/include/asm/psci.h
> +++ b/arch/arm/include/asm/psci.h
> @@ -54,6 +54,10 @@
>  #ifndef __ASSEMBLY__
>  #include <asm/types.h>
>
> +/* These 2 helper functions assume cpu < CONFIG_ARMV7_PSCI_NR_CPUS */
> +u32 psci_get_target_pc(int cpu);
> +void psci_save_target_pc(int cpu, u32 pc);
> +
>  void psci_cpu_entry(void);
>  u32 psci_get_cpu_id(void);
>  u32 psci_get_cpu_stack_top(int cpu);
> --
> 2.8.1
>