From: Andre Przywara <andre.przywara@arm.com>
To: Jaxson Han <jaxson.han@arm.com>
Cc: mark.rutland@arm.com, linux-arm-kernel@lists.infradead.org,
wei.chen@arm.com
Subject: Re: [boot-wrapper PATCH v2 5/8] aarch64: Prepare for lower EL booting
Date: Mon, 24 May 2021 10:33:04 +0100 [thread overview]
Message-ID: <20210524103304.4c9ac90b@slackpad.fritz.box> (raw)
In-Reply-To: <20210521104807.138269-6-jaxson.han@arm.com>
On Fri, 21 May 2021 18:48:04 +0800
Jaxson Han <jaxson.han@arm.com> wrote:
Hi,
> Save SPSR_KERNEL into spsr_to_elx during el3_init.
> The jump_kernel will load spsr_to_elx into spsr_el3.
>
> This change will make it easier to control whether drop to lower EL
> before jumping to the kernel.
Looks good, but this needs some adaption after fixing patch 2/8:
>
> Signed-off-by: Jaxson Han <jaxson.han@arm.com>
> ---
> arch/aarch64/boot.S | 15 +++++++++++++--
> 1 file changed, 13 insertions(+), 2 deletions(-)
>
> diff --git a/arch/aarch64/boot.S b/arch/aarch64/boot.S
> index b8f9e4e..5600859 100644
> --- a/arch/aarch64/boot.S
> +++ b/arch/aarch64/boot.S
> @@ -118,7 +118,16 @@ el3_init:
> mov x0, #ZCR_EL3_LEN_MASK // SVE: Enable full vector len
> msr ZCR_EL3, x0 // for EL2.
>
> -1:
> + /*
> + * Save SPSR_KERNEL into spsr_to_elx.
> + * The jump_kernel will load spsr_to_elx into spsr_el3
> + */
> +1: mov w0, #SPSR_KERNEL
> + ldr x1, =spsr_to_elx
> + str w0, [x1]
> + b el_max_init
> +
> +el_max_init:
> ldr x0, =CNTFRQ
> msr cntfrq_el0, x0
>
> @@ -166,7 +175,7 @@ jump_kernel:
> b.eq 1f
> br x19 // Keep current EL
>
> -1: ldr w4, #SPSR_KERNEL
> +1: ldr w4, spsr_to_elx
This would be the place where you change the original "mov x4,
#SPSR_KERNEL" line into this one here (and not in patch 2).
With that fixed:
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Cheers,
Andre
>
> /*
> * If bit 0 of the kernel address is set, we're entering in AArch32
> @@ -184,3 +193,5 @@ jump_kernel:
> .align 3
> flag_keep_el:
> .long 0
> +spsr_to_elx:
> + .long 0
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next prev parent reply other threads:[~2021-05-24 17:22 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-21 10:47 [boot-wrapper PATCH v2 0/8] Add Armv8-R AArch64 support Jaxson Han
2021-05-21 10:48 ` [boot-wrapper PATCH v2 1/8] Decouple V2M_SYS config by auto-detect dtb node Jaxson Han
2021-05-21 10:48 ` [boot-wrapper PATCH v2 2/8] aarch64: Rename labels and prepare for lower EL booting Jaxson Han
2021-05-24 9:32 ` Andre Przywara
2021-05-25 1:54 ` Jaxson Han
2021-05-21 10:48 ` [boot-wrapper PATCH v2 3/8] aarch64: Remove the redundant setup_stack Jaxson Han
2021-05-24 9:32 ` Andre Przywara
2021-05-21 10:48 ` [boot-wrapper PATCH v2 4/8] aarch64: Prepare for EL1 booting Jaxson Han
2021-05-24 9:32 ` Andre Przywara
2021-05-21 10:48 ` [boot-wrapper PATCH v2 5/8] aarch64: Prepare for lower EL booting Jaxson Han
2021-05-24 9:33 ` Andre Przywara [this message]
2021-05-21 10:48 ` [boot-wrapper PATCH v2 6/8] gic-v3: Prepare for gicv3 with EL2 Jaxson Han
2021-05-24 9:33 ` Andre Przywara
2021-05-21 10:48 ` [boot-wrapper PATCH v2 7/8] aarch64: Prepare for booting " Jaxson Han
2021-05-24 9:33 ` Andre Przywara
2021-05-21 10:48 ` [boot-wrapper PATCH v2 8/8] aarch64: Introduce EL2 boot code for Armv8-R AArch64 Jaxson Han
2021-05-24 10:19 ` Andre Przywara
2021-05-25 1:59 ` Jaxson Han
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