[Intel-xe] [PATCH V4 3/3] drm/xe: Add sysfs entry to report per tile memory size

[Lucas De Marchi]

On Thu, Jun 22, 2023 at 12:58:18PM +0530, Tejas Upadhyay wrote:
>Add sysfs entry to read per tile physical memory
>including stolen memory.
>
>V4:
>  - %s/addr_range/physical_vram_size_byes, make it
>    user readable name - Joonas/Aravind
>  - Display in bytes - Joonas/Aravind
>V3:
>  - Exclude DG1, replace sysfs_create_file/files - Aravind
>V2:
>  - Use DEVICE_ATTR_RO - Aravind
>  - Dont put kobj on sysfs_file_create fail - Himal
>  - Skip addr_range sysfs create for non dgfx - Himal
>
>Reviewed-by: Aravind Iddamsetty <aravind.iddamsetty at intel.com>
>Signed-off-by: Tejas Upadhyay <tejas.upadhyay at intel.com>
>---
> drivers/gpu/drm/xe/xe_device_types.h |  6 ++++++
> drivers/gpu/drm/xe/xe_mmio.c         |  1 +
> drivers/gpu/drm/xe/xe_tile_sysfs.c   | 19 +++++++++++++++++++
> 3 files changed, 26 insertions(+)
>
>diff --git a/drivers/gpu/drm/xe/xe_device_types.h b/drivers/gpu/drm/xe/xe_device_types.h
>index f2d4298fb0a1..dada97352330 100644
>--- a/drivers/gpu/drm/xe/xe_device_types.h
>+++ b/drivers/gpu/drm/xe/xe_device_types.h
>@@ -108,6 +108,12 @@ struct xe_tile {
>
> 	/** @mem: memory management info for tile */
> 	struct {
>+		/**
>+		 * @actual_physical_mem: Track actual VRAM size
>+		 * including stolen mem for tile
>+		 */
>+		resource_size_t actual_physical_mem;

should probably be inside the vram struct below? Then you probably need
to tweak this doc

	/** @size: size of VRAM. */
	resource_size_t size;

to explain how these are different... i.e. that while your
physical_vram_size doesn't exclude anything, "size" excludes reserved
portions (e.g. the stolen memory).  So...

vram {
	io_size - vram that can be accessed by the CPU through the io mapping
	size - probably rename to "usable_size"?, the total vram minus reserved
	       portions
	actual_physical_size - ...
}

Lucas De Marchi

>+
> 		/**
> 		 * @vram: VRAM info for tile.
> 		 *
>diff --git a/drivers/gpu/drm/xe/xe_mmio.c b/drivers/gpu/drm/xe/xe_mmio.c
>index f1336803b915..4bb8e8c3080e 100644
>--- a/drivers/gpu/drm/xe/xe_mmio.c
>+++ b/drivers/gpu/drm/xe/xe_mmio.c
>@@ -277,6 +277,7 @@ int xe_mmio_probe_vram(struct xe_device *xe)
> 		if (err)
> 			return err;
>
>+		tile->mem.actual_physical_mem = tile_size;
> 		tile->mem.vram.io_start = xe->mem.vram.io_start + tile_offset;
> 		tile->mem.vram.io_size = min_t(u64, vram_size, io_size);
>
>diff --git a/drivers/gpu/drm/xe/xe_tile_sysfs.c b/drivers/gpu/drm/xe/xe_tile_sysfs.c
>index 386c6accd4dd..6b559e2f2f7b 100644
>--- a/drivers/gpu/drm/xe/xe_tile_sysfs.c
>+++ b/drivers/gpu/drm/xe/xe_tile_sysfs.c
>@@ -20,6 +20,20 @@ static struct kobj_type xe_tile_sysfs_kobj_type = {
> 	.sysfs_ops = &kobj_sysfs_ops,
> };
>
>+static ssize_t
>+physical_vram_size_bytes_show(struct device *kdev, struct device_attribute *attr,
>+			      char *buf)
>+{
>+	struct xe_tile *tile = kobj_to_tile(&kdev->kobj);
>+
>+	return sysfs_emit(buf, "%llu\n", tile->mem.actual_physical_mem);
>+}
>+
>+static DEVICE_ATTR_RO(physical_vram_size_bytes);
>+
>+static const struct attribute *physical_memsize_attr =
>+	&dev_attr_physical_vram_size_bytes.attr;
>+
> static void tile_sysfs_fini(struct drm_device *drm, void *arg)
> {
> 	struct xe_tile *tile = arg;
>@@ -50,6 +64,11 @@ void xe_tile_sysfs_init(struct xe_tile *tile)
>
> 	tile->sysfs = &kt->base;
>
>+	if (IS_DGFX(xe) && xe->info.platform != XE_DG1 &&
>+	    sysfs_create_file(tile->sysfs, physical_memsize_attr))
>+		drm_warn(&xe->drm,
>+			 "Sysfs creation to read addr_range per tile failed\n");
>+
> 	err = drmm_add_action_or_reset(&xe->drm, tile_sysfs_fini, tile);
> 	if (err) {
> 		drm_warn(&xe->drm, "%s: drmm_add_action_or_reset failed, err: %d\n",
>-- 
>2.25.1
>