Re: [RESEND PATCH] ARM/hw_breakpoint: add ARMv8.1/ARMv8.2 debug architecutre versions support in enable_monitor_mode()

From: Will Deacon
Date: Tue Oct 22 2019 - 08:25:58 EST


On Thu, Sep 26, 2019 at 03:38:28PM +0800, Candle Sun wrote:
> From: Candle Sun <candle.sun@xxxxxxxxxx>
>
> When ARMv8.1/ARMv8.2 cores are used in AArch32 mode,
> arch_hw_breakpoint_init() in arch/arm/kernel/hw_breakpoint.c will be used.
>
> From ARMv8 specification, different debug architecture versions defined:
> * 0110 ARMv8, v8 Debug architecture.
> * 0111 ARMv8.1, v8 Debug architecture, with Virtualization Host Extensions.
> * 1000 ARMv8.2, v8.2 Debug architecture.
>
> So missing ARMv8.1/ARMv8.2 cases will cause enable_monitor_mode() function
> returns -ENODEV, and arch_hw_breakpoint_init() will fail.
>
> Signed-off-by: Candle Sun <candle.sun@xxxxxxxxxx>
> Signed-off-by: Nianfu Bai <nianfu.bai@xxxxxxxxxx>
> ---
> arch/arm/include/asm/hw_breakpoint.h | 2 ++
> arch/arm/kernel/hw_breakpoint.c | 2 ++
> 2 files changed, 4 insertions(+)

[...]

> diff --git a/arch/arm/include/asm/hw_breakpoint.h b/arch/arm/include/asm/hw_breakpoint.h
> index ac54c06..9137ef6 100644
> --- a/arch/arm/include/asm/hw_breakpoint.h
> +++ b/arch/arm/include/asm/hw_breakpoint.h
> @@ -53,6 +53,8 @@ static inline void decode_ctrl_reg(u32 reg,
> #define ARM_DEBUG_ARCH_V7_MM 4
> #define ARM_DEBUG_ARCH_V7_1 5
> #define ARM_DEBUG_ARCH_V8 6
> +#define ARM_DEBUG_ARCH_V8_1 7
> +#define ARM_DEBUG_ARCH_V8_2 8

Looks like you can also add:

#define ARM_DEBUG_ARCH_V8_4 9

and treat that the same way. With that, and a fix to $SUBJECT:

Acked-by: Will Deacon <will@xxxxxxxxxx>

Please put this into the patch system [1].

Will

[1] https://www.arm.linux.org.uk/developer/patches/