[PATCH v2 08/12] drm/panfrost: Do the exception -> string translation using a table

Steven Price steven.price at arm.com
Mon Jun 21 15:19:38 UTC 2021


On 21/06/2021 14:39, Boris Brezillon wrote:
> Do the exception -> string translation using a table so we can add extra
> fields if we need to. While at it add an error field to ease the
> exception -> error conversion which we'll need if we want to set the
> fence error to something that reflects the exception code.
> 
> TODO: fix the error codes.

TODO: Do the TODO ;)

I'm not sure how useful translating the hardware error codes to Linux
ones are. E.g. 'OOM' means something quite different from a normal
-ENOMEM. One is running out of a space in a predefined buffer, the other
is Linux not able to allocate memory.

> 
> Signed-off-by: Boris Brezillon <boris.brezillon at collabora.com>
> ---
>  drivers/gpu/drm/panfrost/panfrost_device.c | 134 +++++++++++++--------
>  drivers/gpu/drm/panfrost/panfrost_device.h |   1 +
>  2 files changed, 88 insertions(+), 47 deletions(-)
> 
> diff --git a/drivers/gpu/drm/panfrost/panfrost_device.c b/drivers/gpu/drm/panfrost/panfrost_device.c
> index f7f5ca94f910..2de011cee258 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_device.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_device.c
> @@ -292,55 +292,95 @@ void panfrost_device_fini(struct panfrost_device *pfdev)
>  	panfrost_clk_fini(pfdev);
>  }
>  
> -const char *panfrost_exception_name(u32 exception_code)
> -{
> -	switch (exception_code) {
> -		/* Non-Fault Status code */
> -	case 0x00: return "NOT_STARTED/IDLE/OK";
> -	case 0x01: return "DONE";
> -	case 0x02: return "INTERRUPTED";
> -	case 0x03: return "STOPPED";
> -	case 0x04: return "TERMINATED";
> -	case 0x08: return "ACTIVE";
> -		/* Job exceptions */
> -	case 0x40: return "JOB_CONFIG_FAULT";
> -	case 0x41: return "JOB_POWER_FAULT";
> -	case 0x42: return "JOB_READ_FAULT";
> -	case 0x43: return "JOB_WRITE_FAULT";
> -	case 0x44: return "JOB_AFFINITY_FAULT";
> -	case 0x48: return "JOB_BUS_FAULT";
> -	case 0x50: return "INSTR_INVALID_PC";
> -	case 0x51: return "INSTR_INVALID_ENC";
> -	case 0x52: return "INSTR_TYPE_MISMATCH";
> -	case 0x53: return "INSTR_OPERAND_FAULT";
> -	case 0x54: return "INSTR_TLS_FAULT";
> -	case 0x55: return "INSTR_BARRIER_FAULT";
> -	case 0x56: return "INSTR_ALIGN_FAULT";
> -	case 0x58: return "DATA_INVALID_FAULT";
> -	case 0x59: return "TILE_RANGE_FAULT";
> -	case 0x5A: return "ADDR_RANGE_FAULT";
> -	case 0x60: return "OUT_OF_MEMORY";
> -		/* GPU exceptions */
> -	case 0x80: return "DELAYED_BUS_FAULT";
> -	case 0x88: return "SHAREABILITY_FAULT";
> -		/* MMU exceptions */
> -	case 0xC1: return "TRANSLATION_FAULT_LEVEL1";
> -	case 0xC2: return "TRANSLATION_FAULT_LEVEL2";
> -	case 0xC3: return "TRANSLATION_FAULT_LEVEL3";
> -	case 0xC4: return "TRANSLATION_FAULT_LEVEL4";
> -	case 0xC8: return "PERMISSION_FAULT";
> -	case 0xC9 ... 0xCF: return "PERMISSION_FAULT";
> -	case 0xD1: return "TRANSTAB_BUS_FAULT_LEVEL1";
> -	case 0xD2: return "TRANSTAB_BUS_FAULT_LEVEL2";
> -	case 0xD3: return "TRANSTAB_BUS_FAULT_LEVEL3";
> -	case 0xD4: return "TRANSTAB_BUS_FAULT_LEVEL4";
> -	case 0xD8: return "ACCESS_FLAG";
> -	case 0xD9 ... 0xDF: return "ACCESS_FLAG";
> -	case 0xE0 ... 0xE7: return "ADDRESS_SIZE_FAULT";
> -	case 0xE8 ... 0xEF: return "MEMORY_ATTRIBUTES_FAULT";
> +#define PANFROST_EXCEPTION(id, err) \
> +	[DRM_PANFROST_EXCEPTION_ ## id] = { \
> +		.name = #id, \
> +		.error = err, \
>  	}
>  
> -	return "UNKNOWN";
> +struct panfrost_exception_info {
> +	const char *name;
> +	int error;
> +};
> +
> +static const struct panfrost_exception_info panfrost_exception_infos[] = {
> +	PANFROST_EXCEPTION(OK, 0),
> +	PANFROST_EXCEPTION(DONE, 0),
> +	PANFROST_EXCEPTION(STOPPED, 0),
> +	PANFROST_EXCEPTION(TERMINATED, 0),

STOPPED/TERMINATED are not really 'success' from an application
perspective. But equally they are ones that need special handling from
the kernel.

> +	PANFROST_EXCEPTION(KABOOM, 0),
> +	PANFROST_EXCEPTION(EUREKA, 0),
> +	PANFROST_EXCEPTION(ACTIVE, 0),
> +	PANFROST_EXCEPTION(JOB_CONFIG_FAULT, -EINVAL),
> +	PANFROST_EXCEPTION(JOB_POWER_FAULT, -ECANCELED),
> +	PANFROST_EXCEPTION(JOB_READ_FAULT, -EINVAL),
> +	PANFROST_EXCEPTION(JOB_WRITE_FAULT, -EINVAL),
> +	PANFROST_EXCEPTION(JOB_AFFINITY_FAULT, -EINVAL),
> +	PANFROST_EXCEPTION(JOB_BUS_FAULT, -EINVAL),
> +	PANFROST_EXCEPTION(INSTR_INVALID_PC, -EINVAL),
> +	PANFROST_EXCEPTION(INSTR_INVALID_ENC, -EINVAL),
> +	PANFROST_EXCEPTION(INSTR_BARRIER_FAULT, -EINVAL),
> +	PANFROST_EXCEPTION(DATA_INVALID_FAULT, -EINVAL),
> +	PANFROST_EXCEPTION(TILE_RANGE_FAULT, -EINVAL),
> +	PANFROST_EXCEPTION(ADDR_RANGE_FAULT, -EINVAL),
> +	PANFROST_EXCEPTION(IMPRECISE_FAULT, -EINVAL),
> +	PANFROST_EXCEPTION(OOM, -ENOMEM),
> +	PANFROST_EXCEPTION(UNKNOWN, -EINVAL),

We should probably make a distinction between this 'special' UNKNOWN
that the hardware can report...

> +	PANFROST_EXCEPTION(DELAYED_BUS_FAULT, -EINVAL),
> +	PANFROST_EXCEPTION(GPU_SHAREABILITY_FAULT, -ECANCELED),
> +	PANFROST_EXCEPTION(SYS_SHAREABILITY_FAULT, -ECANCELED),
> +	PANFROST_EXCEPTION(GPU_CACHEABILITY_FAULT, -ECANCELED),
> +	PANFROST_EXCEPTION(TRANSLATION_FAULT_0, -EINVAL),
> +	PANFROST_EXCEPTION(TRANSLATION_FAULT_1, -EINVAL),
> +	PANFROST_EXCEPTION(TRANSLATION_FAULT_2, -EINVAL),
> +	PANFROST_EXCEPTION(TRANSLATION_FAULT_3, -EINVAL),
> +	PANFROST_EXCEPTION(TRANSLATION_FAULT_4, -EINVAL),
> +	PANFROST_EXCEPTION(TRANSLATION_FAULT_IDENTITY, -EINVAL),
> +	PANFROST_EXCEPTION(PERM_FAULT_0, -EINVAL),
> +	PANFROST_EXCEPTION(PERM_FAULT_1, -EINVAL),
> +	PANFROST_EXCEPTION(PERM_FAULT_2, -EINVAL),
> +	PANFROST_EXCEPTION(PERM_FAULT_3, -EINVAL),
> +	PANFROST_EXCEPTION(TRANSTAB_BUS_FAULT_0, -EINVAL),
> +	PANFROST_EXCEPTION(TRANSTAB_BUS_FAULT_1, -EINVAL),
> +	PANFROST_EXCEPTION(TRANSTAB_BUS_FAULT_2, -EINVAL),
> +	PANFROST_EXCEPTION(TRANSTAB_BUS_FAULT_3, -EINVAL),
> +	PANFROST_EXCEPTION(ACCESS_FLAG_0, -EINVAL),
> +	PANFROST_EXCEPTION(ACCESS_FLAG_1, -EINVAL),
> +	PANFROST_EXCEPTION(ACCESS_FLAG_2, -EINVAL),
> +	PANFROST_EXCEPTION(ACCESS_FLAG_3, -EINVAL),
> +	PANFROST_EXCEPTION(ADDR_SIZE_FAULT_IN0, -EINVAL),
> +	PANFROST_EXCEPTION(ADDR_SIZE_FAULT_IN1, -EINVAL),
> +	PANFROST_EXCEPTION(ADDR_SIZE_FAULT_IN2, -EINVAL),
> +	PANFROST_EXCEPTION(ADDR_SIZE_FAULT_IN3, -EINVAL),
> +	PANFROST_EXCEPTION(ADDR_SIZE_FAULT_OUT0, -EINVAL),
> +	PANFROST_EXCEPTION(ADDR_SIZE_FAULT_OUT1, -EINVAL),
> +	PANFROST_EXCEPTION(ADDR_SIZE_FAULT_OUT2, -EINVAL),
> +	PANFROST_EXCEPTION(ADDR_SIZE_FAULT_OUT3, -EINVAL),
> +	PANFROST_EXCEPTION(MEM_ATTR_FAULT_0, -EINVAL),
> +	PANFROST_EXCEPTION(MEM_ATTR_FAULT_1, -EINVAL),
> +	PANFROST_EXCEPTION(MEM_ATTR_FAULT_2, -EINVAL),
> +	PANFROST_EXCEPTION(MEM_ATTR_FAULT_3, -EINVAL),
> +	PANFROST_EXCEPTION(MEM_ATTR_NONCACHE_0, -EINVAL),
> +	PANFROST_EXCEPTION(MEM_ATTR_NONCACHE_1, -EINVAL),
> +	PANFROST_EXCEPTION(MEM_ATTR_NONCACHE_2, -EINVAL),
> +	PANFROST_EXCEPTION(MEM_ATTR_NONCACHE_3, -EINVAL),
> +};
> +
> +const char *panfrost_exception_name(u32 exception_code)
> +{
> +	if (WARN_ON(exception_code >= ARRAY_SIZE(panfrost_exception_infos) ||
> +		    !panfrost_exception_infos[exception_code].name))
> +		return "UNKNOWN";

...and this UNKNOWN that just means we don't have a clue what the magic
number is.

Steve

> +
> +	return panfrost_exception_infos[exception_code].name;
> +}
> +
> +int panfrost_exception_to_error(u32 exception_code)
> +{
> +	if (WARN_ON(exception_code >= ARRAY_SIZE(panfrost_exception_infos)))
> +		return 0;
> +
> +	return panfrost_exception_infos[exception_code].error;
>  }
>  
>  void panfrost_device_reset(struct panfrost_device *pfdev)
> diff --git a/drivers/gpu/drm/panfrost/panfrost_device.h b/drivers/gpu/drm/panfrost/panfrost_device.h
> index 1c6a3597eba0..498c7b5dccd0 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_device.h
> +++ b/drivers/gpu/drm/panfrost/panfrost_device.h
> @@ -174,6 +174,7 @@ int panfrost_device_resume(struct device *dev);
>  int panfrost_device_suspend(struct device *dev);
>  
>  const char *panfrost_exception_name(u32 exception_code);
> +int panfrost_exception_to_error(u32 exception_code);
>  
>  static inline void
>  panfrost_device_schedule_reset(struct panfrost_device *pfdev)
> 



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