Re: [PATCH v2] ARM/hw_breakpoint: add more ARMv8 debug architecture versions support

[Will Deacon]

On Thu, Oct 24, 2019 at 04:05:39PM +0800, Candle Sun wrote:
> From: Candle Sun <candle.sun@xxxxxxxxxx>
> 
> When ARMv8 cores are used in AArch32 mode, arch_hw_breakpoint_init()
> in arch/arm/kernel/hw_breakpoint.c will be used.
> 
> From ARMv8 specification, v8 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.
> * 1001 ARMv8.4, v8.4 Debug architecture.
> 
> So missing ARMv8.1/ARMv8.2/ARMv8.4 cases will cause
> enable_monitor_mode() returns -ENODEV,and eventually
> arch_hw_breakpoint_init() will fail.
> 
> Signed-off-by: Candle Sun <candle.sun@xxxxxxxxxx>
> Signed-off-by: Nianfu Bai <nianfu.bai@xxxxxxxxxx>
> ---
> Changes in v2:
> - Add ARMv8.4 debug architecture case
> - Update patch description
> ---
>  arch/arm/include/asm/hw_breakpoint.h | 3 +++
>  arch/arm/kernel/hw_breakpoint.c      | 3 +++
>  2 files changed, 6 insertions(+)
> 
> diff --git a/arch/arm/include/asm/hw_breakpoint.h b/arch/arm/include/asm/hw_breakpoint.h
> index ac54c06764e6..62358d3ca0a8 100644
> --- a/arch/arm/include/asm/hw_breakpoint.h
> +++ b/arch/arm/include/asm/hw_breakpoint.h
> @@ -53,6 +53,9 @@ 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
> +#define ARM_DEBUG_ARCH_V8_4	9
>  
>  /* Breakpoint */
>  #define ARM_BREAKPOINT_EXECUTE	0
> diff --git a/arch/arm/kernel/hw_breakpoint.c b/arch/arm/kernel/hw_breakpoint.c
> index b0c195e3a06d..02ca7adf5375 100644
> --- a/arch/arm/kernel/hw_breakpoint.c
> +++ b/arch/arm/kernel/hw_breakpoint.c
> @@ -246,6 +246,9 @@ static int enable_monitor_mode(void)
>  	case ARM_DEBUG_ARCH_V7_ECP14:
>  	case ARM_DEBUG_ARCH_V7_1:
>  	case ARM_DEBUG_ARCH_V8:
> +	case ARM_DEBUG_ARCH_V8_1:
> +	case ARM_DEBUG_ARCH_V8_2:
> +	case ARM_DEBUG_ARCH_V8_4:
>  		ARM_DBG_WRITE(c0, c2, 2, (dscr | ARM_DSCR_MDBGEN));
>  		isb();
>  		break;

Acked-by: Will Deacon <will@xxxxxxxxxx>

Will