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SubjectRe: [PATCH v1 4/5] ARM: tegra: Don't apply CPU erratas in insecure mode
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On 20.05.2018 13:15, Dmitry Osipenko wrote:
> CPU isn't allowed to touch secure registers while running under secure
> monitor. Hence skip applying CPU erratas in the reset handler if Trusted
> Foundations firmware presents.
>
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
> arch/arm/mach-tegra/reset-handler.S | 27 +++++++++++++++++++--------
> arch/arm/mach-tegra/reset.c | 3 +++
> arch/arm/mach-tegra/reset.h | 4 +++-
> 3 files changed, 25 insertions(+), 9 deletions(-)
>
> diff --git a/arch/arm/mach-tegra/reset-handler.S b/arch/arm/mach-tegra/reset-handler.S
> index 805f306fa6f7..d84c74a95806 100644
> --- a/arch/arm/mach-tegra/reset-handler.S
> +++ b/arch/arm/mach-tegra/reset-handler.S
> @@ -121,6 +121,12 @@ ENTRY(__tegra_cpu_reset_handler)
> cpsid aif, 0x13 @ SVC mode, interrupts disabled
>
> tegra_get_soc_id TEGRA_APB_MISC_BASE, r6
> +
> + adr r12, __tegra_cpu_reset_handler_data
> + ldr r0, [r12, #RESET_DATA(TF_PRESENT)]
> + cmp r0, #0
> + bne after_errata
> +
> #ifdef CONFIG_ARCH_TEGRA_2x_SOC
> t20_check:
> cmp r6, #TEGRA20
> @@ -155,7 +161,6 @@ after_errata:
> and r10, r10, #0x3 @ R10 = CPU number
> mov r11, #1
> mov r11, r11, lsl r10 @ R11 = CPU mask
> - adr r12, __tegra_cpu_reset_handler_data
>
> #ifdef CONFIG_SMP
> /* Does the OS know about this CPU? */
> @@ -169,10 +174,9 @@ after_errata:
> cmp r6, #TEGRA20
> bne 1f
> /* If not CPU0, don't let CPU0 reset CPU1 now that CPU1 is coming up. */
> - mov32 r5, TEGRA_IRAM_BASE + TEGRA_IRAM_RESET_HANDLER_OFFSET
> mov r0, #CPU_NOT_RESETTABLE
> cmp r10, #0
> - strneb r0, [r5, #__tegra20_cpu1_resettable_status_offset]
> + strneb r0, [r12, #RESET_DATA(RESETTABLE_STATUS)]
> 1:
> #endif
>
> @@ -278,13 +282,20 @@ ENDPROC(__tegra_cpu_reset_handler)
> .type __tegra_cpu_reset_handler_data, %object
> .globl __tegra_cpu_reset_handler_data
> __tegra_cpu_reset_handler_data:
> - .rept TEGRA_RESET_DATA_SIZE
> - .long 0
> - .endr
> + .long 0 /* TEGRA_RESET_MASK_PRESENT */
> + .long 0 /* TEGRA_RESET_MASK_LP1 */
> + .long 0 /* TEGRA_RESET_MASK_LP2 */
> + .long 0 /* TEGRA_RESET_STARTUP_SECONDARY */
> + .long 0 /* TEGRA_RESET_STARTUP_LP2 */
> + .long 0 /* TEGRA_RESET_STARTUP_LP1 */
> +
> .globl __tegra20_cpu1_resettable_status_offset
> .equ __tegra20_cpu1_resettable_status_offset, \
> . - __tegra_cpu_reset_handler_start
> - .byte 0
> - .align L1_CACHE_SHIFT
> + .long 0 /* TEGRA_RESET_RESETTABLE_STATUS */
>
> + .globl __tegra_tf_present
> + .equ __tegra_tf_present, . - __tegra_cpu_reset_handler_start

I've noticed that __tegra_tf_present shouldn't belong to this patch, I've missed
to remove it while was rebasing.

Also, it occurred to me that it will be much better to remove the whole array
__tegra_cpu_reset_handler_data definition in the asm and get back to the
original ".rept TEGRA_RESET_DATA_SIZE" instead. That will make this part of
code much nicer, I'll change that in v2.

Russell / Thierry, please give you acks-reviews where appropriate and let me
know if I should change anything else in v2, thanks.

> + .long 0 /* TEGRA_RESET_TF_PRESENT */
> + .align L1_CACHE_SHIFT
> ENTRY(__tegra_cpu_reset_handler_end)
> diff --git a/arch/arm/mach-tegra/reset.c b/arch/arm/mach-tegra/reset.c
> index dc558892753c..b02ae7699842 100644
> --- a/arch/arm/mach-tegra/reset.c
> +++ b/arch/arm/mach-tegra/reset.c
> @@ -24,6 +24,7 @@
> #include <asm/cacheflush.h>
> #include <asm/firmware.h>
> #include <asm/hardware/cache-l2x0.h>
> +#include <asm/trusted_foundations.h>
>
> #include "iomap.h"
> #include "irammap.h"
> @@ -89,6 +90,8 @@ static void __init tegra_cpu_reset_handler_enable(void)
>
> void __init tegra_cpu_reset_handler_init(void)
> {
> + __tegra_cpu_reset_handler_data[TEGRA_RESET_TF_PRESENT] =
> + trusted_foundations_registered();
>
> #ifdef CONFIG_SMP
> __tegra_cpu_reset_handler_data[TEGRA_RESET_MASK_PRESENT] =
> diff --git a/arch/arm/mach-tegra/reset.h b/arch/arm/mach-tegra/reset.h
> index 9c479c7925b8..0d9ddc022ece 100644
> --- a/arch/arm/mach-tegra/reset.h
> +++ b/arch/arm/mach-tegra/reset.h
> @@ -25,7 +25,9 @@
> #define TEGRA_RESET_STARTUP_SECONDARY 3
> #define TEGRA_RESET_STARTUP_LP2 4
> #define TEGRA_RESET_STARTUP_LP1 5
> -#define TEGRA_RESET_DATA_SIZE 6
> +#define TEGRA_RESET_RESETTABLE_STATUS 6
> +#define TEGRA_RESET_TF_PRESENT 7
> +#define TEGRA_RESET_DATA_SIZE 8
>
> #ifndef __ASSEMBLY__
>
>

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