Re: [igt-dev] [PATCH v3 1/2] lib/amdgpu: Add helper functions to return MALL support

[Alex Hung <alex.hung@amd.com>]

Reviewed-by: Alex Hung <alex.hung@amd.com>

On 2023-08-08 09:24, Aurabindo Pillai wrote:
> Reads the debugfs file exposed by AMDGPU DM that can be used to find out
> whether the hardware supports certain features, like MALL (Memory access
> at last level)
> 
> Signed-off-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
> ---
>   lib/igt_amd.c | 52 +++++++++++++++++++++++++++++++++++++++++++++++++++
>   lib/igt_amd.h |  3 +++
>   2 files changed, 55 insertions(+)
> 
> diff --git a/lib/igt_amd.c b/lib/igt_amd.c
> index 8da405649..a4dba6bad 100644
> --- a/lib/igt_amd.c
> +++ b/lib/igt_amd.c
> @@ -1144,6 +1144,57 @@ void igt_amd_allow_edp_hotplug_detect(int drm_fd, char *connector_name, bool ena
>   	close(hpd_fd);
>   }
>   
> +static bool get_dm_capabilites(int drm_fd, char *buf, size_t size) {
> +	int ret, fd;
> +	bool has_capablities = amd_has_debugfs(drm_fd, DEBUGFS_DM_CAPABILITIES);
> +
> +	if (!has_capablities)
> +		return false;
> +
> +	fd = igt_debugfs_dir(drm_fd);
> +	if (fd < 0) {
> +		igt_warn("Couldn't open debugfs directory\n");
> +		return -1;
> +	}
> +
> +	ret = igt_debugfs_simple_read(fd, DEBUGFS_DM_CAPABILITIES, buf, (int) size);
> +	igt_assert_f(ret >= 0, "Reading %s failed.\n", DEBUGFS_DM_CAPABILITIES);
> +
> +	close(fd);
> +
> +	if (ret < 0)
> +		return false;
> +
> +	return true;
> +}
> +
> +/**
> + * @brief check if AMDGPU mall_capable interface entry exist and defined
> + *
> + * @param drm_fd DRM file descriptor
> + * @return true if mall_capable debugfs interface exists and defined
> + * @return false otherwise
> + */
> +bool igt_amd_is_mall_capable(int drm_fd)
> +{
> +	char buf[1024], mall_read[10];
> +	char *mall_loc;
> +
> +	if (!get_dm_capabilites(drm_fd, buf, 1024))
> +		return false;
> +
> +	mall_loc = strstr(buf,"mall: ");
> +	if (!mall_loc)
> +		return false;
> +
> +	sscanf(mall_loc, "mall: %s", mall_read);
> +
> +	if (!strcmp(mall_read, "yes"))
> +		return true;
> +
> +	return false;
> +}
> +
>   /**
>    * @brief check if AMDGPU DM visual confirm debugfs interface entry exist and defined
>    *
> @@ -1156,6 +1207,7 @@ bool igt_amd_has_visual_confirm(int drm_fd)
>   	return amd_has_debugfs(drm_fd, DEBUGFS_DM_VISUAL_CONFIRM);
>   }
>   
> +
>   /**
>    * @brief Read amdgpu DM visual confirm debugfs interface
>    *
> diff --git a/lib/igt_amd.h b/lib/igt_amd.h
> index d57390405..6f538a195 100644
> --- a/lib/igt_amd.h
> +++ b/lib/igt_amd.h
> @@ -52,6 +52,7 @@
>   
>   /* amdgpu DM interface entries */
>   #define DEBUGFS_DM_VISUAL_CONFIRM "amdgpu_dm_visual_confirm"
> +#define DEBUGFS_DM_CAPABILITIES "amdgpu_dm_capabilities"
>   
>   enum amd_dsc_clock_force {
>   	DSC_AUTOMATIC = 0,
> @@ -194,4 +195,6 @@ void igt_amd_allow_edp_hotplug_detect(int drm_fd, char *connector_name, bool ena
>   bool igt_amd_has_visual_confirm(int drm_fd);
>   int  igt_amd_get_visual_confirm(int drm_fd);
>   bool igt_amd_set_visual_confirm(int drm_fd, enum amdgpu_debug_visual_confirm option);
> +
> +bool igt_amd_is_mall_capable(int drm_fd);
>   #endif /* IGT_AMD_H */