[PATCH 0/3] Panfrost BO tagging and GEMS debug display

[PATCH 0/3] Panfrost BO tagging and GEMS debug display

[Adrián Larumbe]

This patch series is a Panfrost port of the already merged patches
previously discussed at [1].

The differences are minimal. However, Panfrost doesn't have Kernel-only BO's, so all the
functionality that dealt with them has been removed.

The under-discussion Mesa MR that would allow one to test these changes can be found at [2].

The way BO flags is printed is also slightly different.

[1] https://lore.kernel.org/dri-devel/20250418022710.74749-1-adrian.larumbe@collabora.com/
[2] https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/34224

Adrián Larumbe (3):
  drm/panfrost: Add BO labelling to Panfrost
  drm/panfrost: Add driver IOCTL for setting BO labels
  drm/panfrost: show device-wide list of DRM GEM objects over DebugFS

 drivers/gpu/drm/panfrost/panfrost_device.c |   4 +
 drivers/gpu/drm/panfrost/panfrost_device.h |  11 ++
 drivers/gpu/drm/panfrost/panfrost_drv.c    |  81 ++++++++++-
 drivers/gpu/drm/panfrost/panfrost_gem.c    | 156 +++++++++++++++++++++
 drivers/gpu/drm/panfrost/panfrost_gem.h    |  76 ++++++++++
 include/uapi/drm/panfrost_drm.h            |  20 +++
 6 files changed, 347 insertions(+), 1 deletion(-)


base-commit: a3707f53eb3f4f3e7a30d720be0885f813d649bb
--
2.48.1

[PATCH 1/3] drm/panfrost: Add BO labelling to Panfrost

[Adrián Larumbe]

Unlike in Panthor, from where this change is based on, there is no need
to support tagging of BO's other than UM-exposed ones, so all strings
can be freed with kfree().

This commit is done in preparation of a following one that will allow
UM to set BO labels through a new ioctl().

Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com>
---
 drivers/gpu/drm/panfrost/panfrost_gem.c | 19 +++++++++++++++++++
 drivers/gpu/drm/panfrost/panfrost_gem.h | 16 ++++++++++++++++
 2 files changed, 35 insertions(+)

diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.c b/drivers/gpu/drm/panfrost/panfrost_gem.c
index 963f04ba2de6..a7a29974d8b1 100644
--- a/drivers/gpu/drm/panfrost/panfrost_gem.c
+++ b/drivers/gpu/drm/panfrost/panfrost_gem.c
@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0
 /* Copyright 2019 Linaro, Ltd, Rob Herring <robh@kernel.org> */
 
+#include <linux/cleanup.h>
 #include <linux/err.h>
 #include <linux/slab.h>
 #include <linux/dma-buf.h>
@@ -35,6 +36,9 @@ static void panfrost_gem_free_object(struct drm_gem_object *obj)
 	 */
 	WARN_ON_ONCE(!list_empty(&bo->mappings.list));
 
+	kfree(bo->label.str);
+	mutex_destroy(&bo->label.lock);
+
 	if (bo->sgts) {
 		int i;
 		int n_sgt = bo->base.base.size / SZ_2M;
@@ -260,6 +264,7 @@ struct drm_gem_object *panfrost_gem_create_object(struct drm_device *dev, size_t
 	mutex_init(&obj->mappings.lock);
 	obj->base.base.funcs = &panfrost_gem_funcs;
 	obj->base.map_wc = !pfdev->coherent;
+	mutex_init(&obj->label.lock);
 
 	return &obj->base.base;
 }
@@ -302,3 +307,17 @@ panfrost_gem_prime_import_sg_table(struct drm_device *dev,
 
 	return obj;
 }
+
+void
+panfrost_gem_set_label(struct drm_gem_object *obj, const char *label)
+{
+	struct panfrost_gem_object *bo = to_panfrost_bo(obj);
+	const char *old_label;
+
+	scoped_guard(mutex, &bo->label.lock) {
+		old_label = bo->label.str;
+		bo->label.str = label;
+	}
+
+	kfree(old_label);
+}
diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.h b/drivers/gpu/drm/panfrost/panfrost_gem.h
index 7516b7ecf7fe..c0be2934f229 100644
--- a/drivers/gpu/drm/panfrost/panfrost_gem.h
+++ b/drivers/gpu/drm/panfrost/panfrost_gem.h
@@ -41,6 +41,20 @@ struct panfrost_gem_object {
 	 */
 	size_t heap_rss_size;
 
+	/**
+	 * @label: BO tagging fields. The label can be assigned within the
+	 * driver itself or through a specific IOCTL.
+	 */
+	struct {
+		/**
+		 * @label.str: Pointer to NULL-terminated string,
+		 */
+		const char *str;
+
+		/** @lock.str: Protects access to the @label.str field. */
+		struct mutex lock;
+	} label;
+
 	bool noexec		:1;
 	bool is_heap		:1;
 };
@@ -89,4 +103,6 @@ void panfrost_gem_teardown_mappings_locked(struct panfrost_gem_object *bo);
 int panfrost_gem_shrinker_init(struct drm_device *dev);
 void panfrost_gem_shrinker_cleanup(struct drm_device *dev);
 
+void panfrost_gem_set_label(struct drm_gem_object *obj, const char *label);
+
 #endif /* __PANFROST_GEM_H__ */
-- 
2.48.1

[PATCH 2/3] drm/panfrost: Add driver IOCTL for setting BO labels

[Adrián Larumbe]

Allow UM to label a BO for which it possesses a DRM handle.

Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com>
---
 drivers/gpu/drm/panfrost/panfrost_drv.c | 44 ++++++++++++++++++++++++-
 drivers/gpu/drm/panfrost/panfrost_gem.h |  2 ++
 include/uapi/drm/panfrost_drm.h         | 20 +++++++++++
 3 files changed, 65 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c b/drivers/gpu/drm/panfrost/panfrost_drv.c
index b87f83e94eda..b0ab76d67e96 100644
--- a/drivers/gpu/drm/panfrost/panfrost_drv.c
+++ b/drivers/gpu/drm/panfrost/panfrost_drv.c
@@ -495,6 +495,46 @@ static int panfrost_ioctl_madvise(struct drm_device *dev, void *data,
 	return ret;
 }
 
+static int panfrost_ioctl_set_label_bo(struct drm_device *ddev, void *data,
+				       struct drm_file *file)
+{
+	struct drm_panfrost_set_label_bo *args = data;
+	struct drm_gem_object *obj;
+	const char *label = NULL;
+	int ret = 0;
+
+	if (args->pad)
+		return -EINVAL;
+
+	obj = drm_gem_object_lookup(file, args->handle);
+	if (!obj)
+		return -ENOENT;
+
+	if (args->label) {
+		label = strndup_user((const char __user *)(uintptr_t)args->label,
+				     PANFROST_BO_LABEL_MAXLEN);
+		if (IS_ERR(label)) {
+			ret = PTR_ERR(label);
+			if (ret == -EINVAL)
+				ret = -E2BIG;
+			goto err_put_obj;
+		}
+	}
+
+	/*
+	 * We treat passing a label of length 0 and passing a NULL label
+	 * differently, because even though they might seem conceptually
+	 * similar, future uses of the BO label might expect a different
+	 * behaviour in each case.
+	 */
+	panfrost_gem_set_label(obj, label);
+
+err_put_obj:
+	drm_gem_object_put(obj);
+
+	return ret;
+}
+
 int panfrost_unstable_ioctl_check(void)
 {
 	if (!unstable_ioctls)
@@ -561,6 +601,7 @@ static const struct drm_ioctl_desc panfrost_drm_driver_ioctls[] = {
 	PANFROST_IOCTL(PERFCNT_ENABLE,	perfcnt_enable,	DRM_RENDER_ALLOW),
 	PANFROST_IOCTL(PERFCNT_DUMP,	perfcnt_dump,	DRM_RENDER_ALLOW),
 	PANFROST_IOCTL(MADVISE,		madvise,	DRM_RENDER_ALLOW),
+	PANFROST_IOCTL(SET_LABEL_BO,	set_label_bo,	DRM_RENDER_ALLOW),
 };
 
 static void panfrost_gpu_show_fdinfo(struct panfrost_device *pfdev,
@@ -625,6 +666,7 @@ static const struct file_operations panfrost_drm_driver_fops = {
  * - 1.2 - adds AFBC_FEATURES query
  * - 1.3 - adds JD_REQ_CYCLE_COUNT job requirement for SUBMIT
  *       - adds SYSTEM_TIMESTAMP and SYSTEM_TIMESTAMP_FREQUENCY queries
+ * - 1.4 - adds SET_LABEL_BO
  */
 static const struct drm_driver panfrost_drm_driver = {
 	.driver_features	= DRIVER_RENDER | DRIVER_GEM | DRIVER_SYNCOBJ,
@@ -637,7 +679,7 @@ static const struct drm_driver panfrost_drm_driver = {
 	.name			= "panfrost",
 	.desc			= "panfrost DRM",
 	.major			= 1,
-	.minor			= 3,
+	.minor			= 4,
 
 	.gem_create_object	= panfrost_gem_create_object,
 	.gem_prime_import_sg_table = panfrost_gem_prime_import_sg_table,
diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.h b/drivers/gpu/drm/panfrost/panfrost_gem.h
index c0be2934f229..842e025b9bdc 100644
--- a/drivers/gpu/drm/panfrost/panfrost_gem.h
+++ b/drivers/gpu/drm/panfrost/panfrost_gem.h
@@ -9,6 +9,8 @@
 
 struct panfrost_mmu;
 
+#define PANFROST_BO_LABEL_MAXLEN	4096
+
 struct panfrost_gem_object {
 	struct drm_gem_shmem_object base;
 	struct sg_table *sgts;
diff --git a/include/uapi/drm/panfrost_drm.h b/include/uapi/drm/panfrost_drm.h
index 568724be6628..b0445c5e514d 100644
--- a/include/uapi/drm/panfrost_drm.h
+++ b/include/uapi/drm/panfrost_drm.h
@@ -21,6 +21,7 @@ extern "C" {
 #define DRM_PANFROST_PERFCNT_ENABLE		0x06
 #define DRM_PANFROST_PERFCNT_DUMP		0x07
 #define DRM_PANFROST_MADVISE			0x08
+#define DRM_PANFROST_SET_LABEL_BO		0x09
 
 #define DRM_IOCTL_PANFROST_SUBMIT		DRM_IOW(DRM_COMMAND_BASE + DRM_PANFROST_SUBMIT, struct drm_panfrost_submit)
 #define DRM_IOCTL_PANFROST_WAIT_BO		DRM_IOW(DRM_COMMAND_BASE + DRM_PANFROST_WAIT_BO, struct drm_panfrost_wait_bo)
@@ -29,6 +30,7 @@ extern "C" {
 #define DRM_IOCTL_PANFROST_GET_PARAM		DRM_IOWR(DRM_COMMAND_BASE + DRM_PANFROST_GET_PARAM, struct drm_panfrost_get_param)
 #define DRM_IOCTL_PANFROST_GET_BO_OFFSET	DRM_IOWR(DRM_COMMAND_BASE + DRM_PANFROST_GET_BO_OFFSET, struct drm_panfrost_get_bo_offset)
 #define DRM_IOCTL_PANFROST_MADVISE		DRM_IOWR(DRM_COMMAND_BASE + DRM_PANFROST_MADVISE, struct drm_panfrost_madvise)
+#define DRM_IOCTL_PANFROST_SET_LABEL_BO		DRM_IOWR(DRM_COMMAND_BASE + DRM_PANFROST_SET_LABEL_BO, struct drm_panfrost_set_label_bo)
 
 /*
  * Unstable ioctl(s): only exposed when the unsafe unstable_ioctls module
@@ -227,6 +229,24 @@ struct drm_panfrost_madvise {
 	__u32 retained;       /* out, whether backing store still exists */
 };
 
+/**
+ * struct drm_panfrost_set_label_bo - ioctl argument for labelling Panfrost BOs.
+ */
+struct drm_panfrost_set_label_bo {
+	/** @handle: Handle of the buffer object to label. */
+	__u32 handle;
+
+	/**  @pad: MBZ. */
+	__u32 pad;
+
+	/**
+	 * @label: User pointer to a NUL-terminated string
+	 *
+	 * Length cannot be greater than 4096
+	 */
+	__u64 label;
+};
+
 /* Definitions for coredump decoding in user space */
 #define PANFROSTDUMP_MAJOR 1
 #define PANFROSTDUMP_MINOR 0
-- 
2.48.1

[PATCH 3/3] drm/panfrost: show device-wide list of DRM GEM objects over DebugFS

[Adrián Larumbe]

This change is essentially a Panfrost port of commit a3707f53eb3f
("drm/panthor: show device-wide list of DRM GEM objects over DebugFS").

The DebugFS file is almost the same as in Panthor, minus the GEM object
usage flags, since Panfrost has no kernel-only BO's.

Two additional GEM state flags which are displayed but aren't relevant
to Panthor are 'Purged' and 'Purgeable', since Panfrost implements an
explicit shrinker and a madvise ioctl to flag objects as reclaimable.

Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com>
---
 drivers/gpu/drm/panfrost/panfrost_device.c |   4 +
 drivers/gpu/drm/panfrost/panfrost_device.h |  11 ++
 drivers/gpu/drm/panfrost/panfrost_drv.c    |  37 ++++++
 drivers/gpu/drm/panfrost/panfrost_gem.c    | 137 +++++++++++++++++++++
 drivers/gpu/drm/panfrost/panfrost_gem.h    |  58 +++++++++
 5 files changed, 247 insertions(+)

diff --git a/drivers/gpu/drm/panfrost/panfrost_device.c b/drivers/gpu/drm/panfrost/panfrost_device.c
index a45e4addcc19..7ba140aaf59d 100644
--- a/drivers/gpu/drm/panfrost/panfrost_device.c
+++ b/drivers/gpu/drm/panfrost/panfrost_device.c
@@ -209,6 +209,10 @@ int panfrost_device_init(struct panfrost_device *pfdev)
 
 	spin_lock_init(&pfdev->cycle_counter.lock);
 
+#ifdef CONFIG_DEBUG_FS
+	mutex_init(&pfdev->gems.lock);
+	INIT_LIST_HEAD(&pfdev->gems.node);
+#endif
 	err = panfrost_clk_init(pfdev);
 	if (err) {
 		dev_err(pfdev->dev, "clk init failed %d\n", err);
diff --git a/drivers/gpu/drm/panfrost/panfrost_device.h b/drivers/gpu/drm/panfrost/panfrost_device.h
index ad95f2ed31d9..395272a79306 100644
--- a/drivers/gpu/drm/panfrost/panfrost_device.h
+++ b/drivers/gpu/drm/panfrost/panfrost_device.h
@@ -161,6 +161,17 @@ struct panfrost_device {
 		atomic_t use_count;
 		spinlock_t lock;
 	} cycle_counter;
+
+	#ifdef CONFIG_DEBUG_FS
+	/** @gems: Device-wide list of GEM objects owned by at least one file. */
+	struct {
+		/** @gems.lock: Protects the device-wide list of GEM objects. */
+		struct mutex lock;
+
+		/** @node: Used to keep track of all the device's DRM objects */
+		struct list_head node;
+	} gems;
+#endif
 };
 
 struct panfrost_mmu {
diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c b/drivers/gpu/drm/panfrost/panfrost_drv.c
index b0ab76d67e96..12dd9f311984 100644
--- a/drivers/gpu/drm/panfrost/panfrost_drv.c
+++ b/drivers/gpu/drm/panfrost/panfrost_drv.c
@@ -13,6 +13,7 @@
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 #include <drm/panfrost_drm.h>
+#include <drm/drm_debugfs.h>
 #include <drm/drm_drv.h>
 #include <drm/drm_ioctl.h>
 #include <drm/drm_syncobj.h>
@@ -153,6 +154,8 @@ static int panfrost_ioctl_create_bo(struct drm_device *dev, void *data,
 		ret = -EINVAL;
 	}
 
+	panfrost_gem_debugfs_init_bo(bo);
+
 out:
 	drm_gem_object_put(&bo->base.base);
 	return ret;
@@ -659,6 +662,37 @@ static const struct file_operations panfrost_drm_driver_fops = {
 	.show_fdinfo = drm_show_fdinfo,
 };
 
+#ifdef CONFIG_DEBUG_FS
+static int panthor_gems_show(struct seq_file *m, void *data)
+{
+	struct drm_info_node *node = m->private;
+	struct drm_device *dev = node->minor->dev;
+	struct panfrost_device *pfdev = dev->dev_private;
+
+	panfrost_gem_debugfs_print_bos(pfdev, m);
+
+	return 0;
+}
+
+static struct drm_info_list panthor_debugfs_list[] = {
+	{"gems", panthor_gems_show, 0, NULL},
+};
+
+static int panthor_gems_debugfs_init(struct drm_minor *minor)
+{
+	drm_debugfs_create_files(panthor_debugfs_list,
+				 ARRAY_SIZE(panthor_debugfs_list),
+				 minor->debugfs_root, minor);
+
+	return 0;
+}
+
+static void panfrost_debugfs_init(struct drm_minor *minor)
+{
+	panthor_gems_debugfs_init(minor);
+}
+#endif
+
 /*
  * Panfrost driver version:
  * - 1.0 - initial interface
@@ -683,6 +717,9 @@ static const struct drm_driver panfrost_drm_driver = {
 
 	.gem_create_object	= panfrost_gem_create_object,
 	.gem_prime_import_sg_table = panfrost_gem_prime_import_sg_table,
+#ifdef CONFIG_DEBUG_FS
+	.debugfs_init = panfrost_debugfs_init,
+#endif
 };
 
 static int panfrost_probe(struct platform_device *pdev)
diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.c b/drivers/gpu/drm/panfrost/panfrost_gem.c
index a7a29974d8b1..8a0fd1abd05c 100644
--- a/drivers/gpu/drm/panfrost/panfrost_gem.c
+++ b/drivers/gpu/drm/panfrost/panfrost_gem.c
@@ -12,6 +12,38 @@
 #include "panfrost_gem.h"
 #include "panfrost_mmu.h"
 
+#ifdef CONFIG_DEBUG_FS
+static void panfrost_gem_debugfs_bo_add(struct panfrost_device *ptdev,
+					struct panfrost_gem_object *bo)
+{
+	INIT_LIST_HEAD(&bo->debugfs.node);
+
+	bo->debugfs.creator.tgid = current->group_leader->pid;
+	get_task_comm(bo->debugfs.creator.process_name, current->group_leader);
+
+	mutex_lock(&ptdev->gems.lock);
+	list_add_tail(&bo->debugfs.node, &ptdev->gems.node);
+	mutex_unlock(&ptdev->gems.lock);
+}
+
+static void panfrost_gem_debugfs_bo_rm(struct panfrost_gem_object *bo)
+{
+	struct panfrost_device *ptdev = bo->base.base.dev->dev_private;
+
+	if (list_empty(&bo->debugfs.node))
+		return;
+
+	mutex_lock(&ptdev->gems.lock);
+	list_del_init(&bo->debugfs.node);
+	mutex_unlock(&ptdev->gems.lock);
+}
+#else
+static void panfrost_gem_debugfs_bo_add(struct panfrost_device *ptdev,
+					struct panfrost_gem_object *bo)
+{}
+static void panfrost_gem_debugfs_bo_rm(struct panfrost_gem_object *bo) {}
+#endif
+
 /* Called DRM core on the last userspace/kernel unreference of the
  * BO.
  */
@@ -36,6 +68,7 @@ static void panfrost_gem_free_object(struct drm_gem_object *obj)
 	 */
 	WARN_ON_ONCE(!list_empty(&bo->mappings.list));
 
+	panfrost_gem_debugfs_bo_rm(bo);
 	kfree(bo->label.str);
 	mutex_destroy(&bo->label.lock);
 
@@ -266,6 +299,8 @@ struct drm_gem_object *panfrost_gem_create_object(struct drm_device *dev, size_t
 	obj->base.map_wc = !pfdev->coherent;
 	mutex_init(&obj->label.lock);
 
+	panfrost_gem_debugfs_bo_add(pfdev, obj);
+
 	return &obj->base.base;
 }
 
@@ -321,3 +356,105 @@ panfrost_gem_set_label(struct drm_gem_object *obj, const char *label)
 
 	kfree(old_label);
 }
+
+#ifdef CONFIG_DEBUG_FS
+struct gem_size_totals {
+	size_t size;
+	size_t resident;
+	size_t reclaimable;
+};
+
+struct flag_def {
+	u32 flag;
+	const char *name;
+};
+
+static void panfrost_gem_debugfs_print_flag_names(struct seq_file *m)
+{
+	int len;
+	int i;
+
+	static const struct flag_def gem_state_flags_names[] = {
+		{PANFROST_DEBUGFS_GEM_STATE_FLAG_IMPORTED, "imported"},
+		{PANFROST_DEBUGFS_GEM_STATE_FLAG_EXPORTED, "exported"},
+		{PANFROST_DEBUGFS_GEM_STATE_FLAG_PURGED, "purged"},
+		{PANFROST_DEBUGFS_GEM_STATE_FLAG_PURGEABLE, "purgeable"},
+	};
+
+	seq_puts(m, "GEM state flags: ");
+	for (i = 0, len = ARRAY_SIZE(gem_state_flags_names); i < len; i++) {
+		seq_printf(m, "%s (0x%x)%s", gem_state_flags_names[i].name,
+			   gem_state_flags_names[i].flag, (i < len - 1) ? ", " : "\n\n");
+	}
+}
+
+static void panfrost_gem_debugfs_bo_print(struct panfrost_gem_object *bo,
+					  struct seq_file *m,
+					  struct gem_size_totals *totals)
+{
+	unsigned int refcount = kref_read(&bo->base.base.refcount);
+	char creator_info[32] = {};
+	size_t resident_size;
+	u32 gem_state_flags = 0;
+
+	/* Skip BOs being destroyed. */
+	if (!refcount)
+		return;
+
+	resident_size = bo->base.pages ? bo->base.base.size : 0;
+
+	snprintf(creator_info, sizeof(creator_info),
+		 "%s/%d", bo->debugfs.creator.process_name, bo->debugfs.creator.tgid);
+	seq_printf(m, "%-32s%-16d%-16d%-16zd%-16zd0x%-16lx",
+		   creator_info,
+		   bo->base.base.name,
+		   refcount,
+		   bo->base.base.size,
+		   resident_size,
+		   drm_vma_node_start(&bo->base.base.vma_node));
+
+	if (bo->base.base.import_attach)
+		gem_state_flags |= PANFROST_DEBUGFS_GEM_STATE_FLAG_IMPORTED;
+	if (bo->base.base.dma_buf)
+		gem_state_flags |= PANFROST_DEBUGFS_GEM_STATE_FLAG_EXPORTED;
+
+	if (bo->base.madv < 0)
+		gem_state_flags |= PANFROST_DEBUGFS_GEM_STATE_FLAG_PURGED;
+	else if (bo->base.madv > 0)
+		gem_state_flags |= PANFROST_DEBUGFS_GEM_STATE_FLAG_PURGEABLE;
+
+	seq_printf(m, "0x%-10x", gem_state_flags);
+
+	scoped_guard(mutex, &bo->label.lock) {
+		seq_printf(m, "%s\n", bo->label.str ? : "");
+	}
+
+	totals->size += bo->base.base.size;
+	totals->resident += resident_size;
+	if (bo->base.madv > 0)
+		totals->reclaimable += resident_size;
+}
+
+void panfrost_gem_debugfs_print_bos(struct panfrost_device *ptdev,
+				    struct seq_file *m)
+{
+	struct gem_size_totals totals = {0};
+	struct panfrost_gem_object *bo;
+
+	panfrost_gem_debugfs_print_flag_names(m);
+
+	seq_puts(m, "created-by                      global-name     refcount        size            resident-size   file-offset       state       label\n");
+	seq_puts(m, "-----------------------------------------------------------------------------------------------------------------------------------\n");
+
+	scoped_guard(mutex, &ptdev->gems.lock) {
+		list_for_each_entry(bo, &ptdev->gems.node, debugfs.node) {
+			if (bo->debugfs.initialised)
+				panfrost_gem_debugfs_bo_print(bo, m, &totals);
+		}
+	}
+
+	seq_puts(m, "===================================================================================================================================\n");
+	seq_printf(m, "Total size: %zd, Total resident: %zd, Total reclaimable: %zd\n",
+		   totals.size, totals.resident, totals.reclaimable);
+}
+#endif
diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.h b/drivers/gpu/drm/panfrost/panfrost_gem.h
index 842e025b9bdc..bc60e0d74da9 100644
--- a/drivers/gpu/drm/panfrost/panfrost_gem.h
+++ b/drivers/gpu/drm/panfrost/panfrost_gem.h
@@ -8,9 +8,50 @@
 #include <drm/drm_mm.h>
 
 struct panfrost_mmu;
+struct panfrost_device;
 
 #define PANFROST_BO_LABEL_MAXLEN	4096
 
+enum panfrost_debugfs_gem_state_flags {
+	/** @PANFROST_DEBUGFS_GEM_STATE_FLAG_IMPORTED: GEM BO is PRIME imported. */
+	PANFROST_DEBUGFS_GEM_STATE_FLAG_IMPORTED = BIT(0),
+
+	/** @PANFROST_DEBUGFS_GEM_STATE_FLAG_EXPORTED: GEM BO is PRIME exported. */
+	PANFROST_DEBUGFS_GEM_STATE_FLAG_EXPORTED = BIT(1),
+
+	/** @PANFROST_DEBUGFS_GEM_STATE_FLAG_PURGED: GEM BO was reclaimed by the shrinker. */
+	PANFROST_DEBUGFS_GEM_STATE_FLAG_PURGED = BIT(2),
+
+	/**
+	 * @PANFROST_DEBUGFS_GEM_STATE_FLAG_PURGEABLE: GEM BO pages were marked as no longer
+	 * needed by UM and can be reclaimed by the shrinker.
+	 */
+	PANFROST_DEBUGFS_GEM_STATE_FLAG_PURGEABLE = BIT(3),
+};
+
+/**
+ * struct panfrost_gem_debugfs - GEM object's DebugFS list information
+ */
+struct panfrost_gem_debugfs {
+	/**
+	 * @node: Node used to insert the object in the device-wide list of
+	 * GEM objects, to display information about it through a DebugFS file.
+	 */
+	struct list_head node;
+
+	/** @creator: Information about the UM process which created the GEM. */
+	struct {
+		/** @creator.process_name: Group leader name in owning thread's process */
+		char process_name[TASK_COMM_LEN];
+
+		/** @creator.tgid: PID of the thread's group leader within its process */
+		pid_t tgid;
+	} creator;
+
+	/** @initialised: GEM object is ready to be displayed in DebugFS file. */
+	bool initialised;
+};
+
 struct panfrost_gem_object {
 	struct drm_gem_shmem_object base;
 	struct sg_table *sgts;
@@ -59,6 +100,10 @@ struct panfrost_gem_object {
 
 	bool noexec		:1;
 	bool is_heap		:1;
+
+#ifdef CONFIG_DEBUG_FS
+	struct panfrost_gem_debugfs debugfs;
+#endif
 };
 
 struct panfrost_gem_mapping {
@@ -107,4 +152,17 @@ void panfrost_gem_shrinker_cleanup(struct drm_device *dev);
 
 void panfrost_gem_set_label(struct drm_gem_object *obj, const char *label);
 
+#ifdef CONFIG_DEBUG_FS
+void panfrost_gem_debugfs_print_bos(struct panfrost_device *pfdev,
+				    struct seq_file *m);
+static inline void
+panfrost_gem_debugfs_init_bo(struct panfrost_gem_object *bo)
+{
+	bo->debugfs.initialised = true;
+}
+#else
+static inline void
+panfrost_gem_debugfs_init_bo(struct panfrost_gem_object *bo) {};
+#endif
+
 #endif /* __PANFROST_GEM_H__ */
-- 
2.48.1

Re: [PATCH 1/3] drm/panfrost: Add BO labelling to Panfrost

[Boris Brezillon]

On Thu, 24 Apr 2025 03:21:30 +0100
Adrián Larumbe <adrian.larumbe@collabora.com> wrote:

> Unlike in Panthor, from where this change is based on, there is no need
> to support tagging of BO's other than UM-exposed ones, so all strings
> can be freed with kfree().
> 
> This commit is done in preparation of a following one that will allow
> UM to set BO labels through a new ioctl().
> 
> Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com>
> ---
>  drivers/gpu/drm/panfrost/panfrost_gem.c | 19 +++++++++++++++++++
>  drivers/gpu/drm/panfrost/panfrost_gem.h | 16 ++++++++++++++++
>  2 files changed, 35 insertions(+)
> 
> diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.c b/drivers/gpu/drm/panfrost/panfrost_gem.c
> index 963f04ba2de6..a7a29974d8b1 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_gem.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_gem.c
> @@ -1,6 +1,7 @@
>  // SPDX-License-Identifier: GPL-2.0
>  /* Copyright 2019 Linaro, Ltd, Rob Herring <robh@kernel.org> */
>  
> +#include <linux/cleanup.h>
>  #include <linux/err.h>
>  #include <linux/slab.h>
>  #include <linux/dma-buf.h>
> @@ -35,6 +36,9 @@ static void panfrost_gem_free_object(struct drm_gem_object *obj)
>  	 */
>  	WARN_ON_ONCE(!list_empty(&bo->mappings.list));
>  
> +	kfree(bo->label.str);
> +	mutex_destroy(&bo->label.lock);
> +
>  	if (bo->sgts) {
>  		int i;
>  		int n_sgt = bo->base.base.size / SZ_2M;
> @@ -260,6 +264,7 @@ struct drm_gem_object *panfrost_gem_create_object(struct drm_device *dev, size_t
>  	mutex_init(&obj->mappings.lock);
>  	obj->base.base.funcs = &panfrost_gem_funcs;
>  	obj->base.map_wc = !pfdev->coherent;
> +	mutex_init(&obj->label.lock);
>  
>  	return &obj->base.base;
>  }
> @@ -302,3 +307,17 @@ panfrost_gem_prime_import_sg_table(struct drm_device *dev,
>  
>  	return obj;
>  }
> +
> +void
> +panfrost_gem_set_label(struct drm_gem_object *obj, const char *label)
> +{
> +	struct panfrost_gem_object *bo = to_panfrost_bo(obj);
> +	const char *old_label;
> +
> +	scoped_guard(mutex, &bo->label.lock) {
> +		old_label = bo->label.str;
> +		bo->label.str = label;
> +	}
> +
> +	kfree(old_label);
> +}
> diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.h b/drivers/gpu/drm/panfrost/panfrost_gem.h
> index 7516b7ecf7fe..c0be2934f229 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_gem.h
> +++ b/drivers/gpu/drm/panfrost/panfrost_gem.h
> @@ -41,6 +41,20 @@ struct panfrost_gem_object {
>  	 */
>  	size_t heap_rss_size;
>  
> +	/**
> +	 * @label: BO tagging fields. The label can be assigned within the
> +	 * driver itself or through a specific IOCTL.
> +	 */
> +	struct {
> +		/**
> +		 * @label.str: Pointer to NULL-terminated string,
> +		 */
> +		const char *str;
> +
> +		/** @lock.str: Protects access to the @label.str field. */
> +		struct mutex lock;
> +	} label;

Should we have a panfrost_gem_debugfs where we put all the debugfs
fields, like we have in panthor?

> +
>  	bool noexec		:1;
>  	bool is_heap		:1;
>  };
> @@ -89,4 +103,6 @@ void panfrost_gem_teardown_mappings_locked(struct panfrost_gem_object *bo);
>  int panfrost_gem_shrinker_init(struct drm_device *dev);
>  void panfrost_gem_shrinker_cleanup(struct drm_device *dev);
>  
> +void panfrost_gem_set_label(struct drm_gem_object *obj, const char *label);
> +
>  #endif /* __PANFROST_GEM_H__ */

Re: [PATCH 1/3] drm/panfrost: Add BO labelling to Panfrost

[Boris Brezillon]

On Thu, 24 Apr 2025 03:21:30 +0100
Adrián Larumbe <adrian.larumbe@collabora.com> wrote:

> Unlike in Panthor, from where this change is based on, there is no need
> to support tagging of BO's other than UM-exposed ones, so all strings
> can be freed with kfree().
> 
> This commit is done in preparation of a following one that will allow
> UM to set BO labels through a new ioctl().
> 
> Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com>
> ---
>  drivers/gpu/drm/panfrost/panfrost_gem.c | 19 +++++++++++++++++++
>  drivers/gpu/drm/panfrost/panfrost_gem.h | 16 ++++++++++++++++
>  2 files changed, 35 insertions(+)
> 
> diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.c b/drivers/gpu/drm/panfrost/panfrost_gem.c
> index 963f04ba2de6..a7a29974d8b1 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_gem.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_gem.c
> @@ -1,6 +1,7 @@
>  // SPDX-License-Identifier: GPL-2.0
>  /* Copyright 2019 Linaro, Ltd, Rob Herring <robh@kernel.org> */
>  
> +#include <linux/cleanup.h>
>  #include <linux/err.h>
>  #include <linux/slab.h>
>  #include <linux/dma-buf.h>
> @@ -35,6 +36,9 @@ static void panfrost_gem_free_object(struct drm_gem_object *obj)
>  	 */
>  	WARN_ON_ONCE(!list_empty(&bo->mappings.list));
>  
> +	kfree(bo->label.str);
> +	mutex_destroy(&bo->label.lock);
> +
>  	if (bo->sgts) {
>  		int i;
>  		int n_sgt = bo->base.base.size / SZ_2M;
> @@ -260,6 +264,7 @@ struct drm_gem_object *panfrost_gem_create_object(struct drm_device *dev, size_t
>  	mutex_init(&obj->mappings.lock);
>  	obj->base.base.funcs = &panfrost_gem_funcs;
>  	obj->base.map_wc = !pfdev->coherent;
> +	mutex_init(&obj->label.lock);
>  
>  	return &obj->base.base;
>  }
> @@ -302,3 +307,17 @@ panfrost_gem_prime_import_sg_table(struct drm_device *dev,
>  
>  	return obj;
>  }
> +
> +void
> +panfrost_gem_set_label(struct drm_gem_object *obj, const char *label)
> +{
> +	struct panfrost_gem_object *bo = to_panfrost_bo(obj);
> +	const char *old_label;
> +
> +	scoped_guard(mutex, &bo->label.lock) {
> +		old_label = bo->label.str;
> +		bo->label.str = label;
> +	}
> +
> +	kfree(old_label);
> +}
> diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.h b/drivers/gpu/drm/panfrost/panfrost_gem.h
> index 7516b7ecf7fe..c0be2934f229 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_gem.h
> +++ b/drivers/gpu/drm/panfrost/panfrost_gem.h
> @@ -41,6 +41,20 @@ struct panfrost_gem_object {
>  	 */
>  	size_t heap_rss_size;
>  
> +	/**
> +	 * @label: BO tagging fields. The label can be assigned within the
> +	 * driver itself or through a specific IOCTL.
> +	 */
> +	struct {
> +		/**
> +		 * @label.str: Pointer to NULL-terminated string,
> +		 */
> +		const char *str;
> +
> +		/** @lock.str: Protects access to the @label.str field. */
> +		struct mutex lock;
> +	} label;

Can we do as we did in panthor, and put those fields in the debugfs
field.

> +
>  	bool noexec		:1;
>  	bool is_heap		:1;
>  };
> @@ -89,4 +103,6 @@ void panfrost_gem_teardown_mappings_locked(struct panfrost_gem_object *bo);
>  int panfrost_gem_shrinker_init(struct drm_device *dev);
>  void panfrost_gem_shrinker_cleanup(struct drm_device *dev);
>  
> +void panfrost_gem_set_label(struct drm_gem_object *obj, const char *label);
> +
>  #endif /* __PANFROST_GEM_H__ */

Re: [PATCH 2/3] drm/panfrost: Add driver IOCTL for setting BO labels

[Boris Brezillon]

On Thu, 24 Apr 2025 03:21:31 +0100
Adrián Larumbe <adrian.larumbe@collabora.com> wrote:

> Allow UM to label a BO for which it possesses a DRM handle.
> 
> Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com>

Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>

> ---
>  drivers/gpu/drm/panfrost/panfrost_drv.c | 44 ++++++++++++++++++++++++-
>  drivers/gpu/drm/panfrost/panfrost_gem.h |  2 ++
>  include/uapi/drm/panfrost_drm.h         | 20 +++++++++++
>  3 files changed, 65 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c b/drivers/gpu/drm/panfrost/panfrost_drv.c
> index b87f83e94eda..b0ab76d67e96 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_drv.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_drv.c
> @@ -495,6 +495,46 @@ static int panfrost_ioctl_madvise(struct drm_device *dev, void *data,
>  	return ret;
>  }
>  
> +static int panfrost_ioctl_set_label_bo(struct drm_device *ddev, void *data,
> +				       struct drm_file *file)
> +{
> +	struct drm_panfrost_set_label_bo *args = data;
> +	struct drm_gem_object *obj;
> +	const char *label = NULL;
> +	int ret = 0;
> +
> +	if (args->pad)
> +		return -EINVAL;
> +
> +	obj = drm_gem_object_lookup(file, args->handle);
> +	if (!obj)
> +		return -ENOENT;
> +
> +	if (args->label) {
> +		label = strndup_user((const char __user *)(uintptr_t)args->label,
> +				     PANFROST_BO_LABEL_MAXLEN);
> +		if (IS_ERR(label)) {
> +			ret = PTR_ERR(label);
> +			if (ret == -EINVAL)
> +				ret = -E2BIG;
> +			goto err_put_obj;
> +		}
> +	}
> +
> +	/*
> +	 * We treat passing a label of length 0 and passing a NULL label
> +	 * differently, because even though they might seem conceptually
> +	 * similar, future uses of the BO label might expect a different
> +	 * behaviour in each case.
> +	 */
> +	panfrost_gem_set_label(obj, label);
> +
> +err_put_obj:
> +	drm_gem_object_put(obj);
> +
> +	return ret;
> +}
> +
>  int panfrost_unstable_ioctl_check(void)
>  {
>  	if (!unstable_ioctls)
> @@ -561,6 +601,7 @@ static const struct drm_ioctl_desc panfrost_drm_driver_ioctls[] = {
>  	PANFROST_IOCTL(PERFCNT_ENABLE,	perfcnt_enable,	DRM_RENDER_ALLOW),
>  	PANFROST_IOCTL(PERFCNT_DUMP,	perfcnt_dump,	DRM_RENDER_ALLOW),
>  	PANFROST_IOCTL(MADVISE,		madvise,	DRM_RENDER_ALLOW),
> +	PANFROST_IOCTL(SET_LABEL_BO,	set_label_bo,	DRM_RENDER_ALLOW),
>  };
>  
>  static void panfrost_gpu_show_fdinfo(struct panfrost_device *pfdev,
> @@ -625,6 +666,7 @@ static const struct file_operations panfrost_drm_driver_fops = {
>   * - 1.2 - adds AFBC_FEATURES query
>   * - 1.3 - adds JD_REQ_CYCLE_COUNT job requirement for SUBMIT
>   *       - adds SYSTEM_TIMESTAMP and SYSTEM_TIMESTAMP_FREQUENCY queries
> + * - 1.4 - adds SET_LABEL_BO
>   */
>  static const struct drm_driver panfrost_drm_driver = {
>  	.driver_features	= DRIVER_RENDER | DRIVER_GEM | DRIVER_SYNCOBJ,
> @@ -637,7 +679,7 @@ static const struct drm_driver panfrost_drm_driver = {
>  	.name			= "panfrost",
>  	.desc			= "panfrost DRM",
>  	.major			= 1,
> -	.minor			= 3,
> +	.minor			= 4,
>  
>  	.gem_create_object	= panfrost_gem_create_object,
>  	.gem_prime_import_sg_table = panfrost_gem_prime_import_sg_table,
> diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.h b/drivers/gpu/drm/panfrost/panfrost_gem.h
> index c0be2934f229..842e025b9bdc 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_gem.h
> +++ b/drivers/gpu/drm/panfrost/panfrost_gem.h
> @@ -9,6 +9,8 @@
>  
>  struct panfrost_mmu;
>  
> +#define PANFROST_BO_LABEL_MAXLEN	4096
> +
>  struct panfrost_gem_object {
>  	struct drm_gem_shmem_object base;
>  	struct sg_table *sgts;
> diff --git a/include/uapi/drm/panfrost_drm.h b/include/uapi/drm/panfrost_drm.h
> index 568724be6628..b0445c5e514d 100644
> --- a/include/uapi/drm/panfrost_drm.h
> +++ b/include/uapi/drm/panfrost_drm.h
> @@ -21,6 +21,7 @@ extern "C" {
>  #define DRM_PANFROST_PERFCNT_ENABLE		0x06
>  #define DRM_PANFROST_PERFCNT_DUMP		0x07
>  #define DRM_PANFROST_MADVISE			0x08
> +#define DRM_PANFROST_SET_LABEL_BO		0x09
>  
>  #define DRM_IOCTL_PANFROST_SUBMIT		DRM_IOW(DRM_COMMAND_BASE + DRM_PANFROST_SUBMIT, struct drm_panfrost_submit)
>  #define DRM_IOCTL_PANFROST_WAIT_BO		DRM_IOW(DRM_COMMAND_BASE + DRM_PANFROST_WAIT_BO, struct drm_panfrost_wait_bo)
> @@ -29,6 +30,7 @@ extern "C" {
>  #define DRM_IOCTL_PANFROST_GET_PARAM		DRM_IOWR(DRM_COMMAND_BASE + DRM_PANFROST_GET_PARAM, struct drm_panfrost_get_param)
>  #define DRM_IOCTL_PANFROST_GET_BO_OFFSET	DRM_IOWR(DRM_COMMAND_BASE + DRM_PANFROST_GET_BO_OFFSET, struct drm_panfrost_get_bo_offset)
>  #define DRM_IOCTL_PANFROST_MADVISE		DRM_IOWR(DRM_COMMAND_BASE + DRM_PANFROST_MADVISE, struct drm_panfrost_madvise)
> +#define DRM_IOCTL_PANFROST_SET_LABEL_BO		DRM_IOWR(DRM_COMMAND_BASE + DRM_PANFROST_SET_LABEL_BO, struct drm_panfrost_set_label_bo)
>  
>  /*
>   * Unstable ioctl(s): only exposed when the unsafe unstable_ioctls module
> @@ -227,6 +229,24 @@ struct drm_panfrost_madvise {
>  	__u32 retained;       /* out, whether backing store still exists */
>  };
>  
> +/**
> + * struct drm_panfrost_set_label_bo - ioctl argument for labelling Panfrost BOs.
> + */
> +struct drm_panfrost_set_label_bo {
> +	/** @handle: Handle of the buffer object to label. */
> +	__u32 handle;
> +
> +	/**  @pad: MBZ. */
> +	__u32 pad;
> +
> +	/**
> +	 * @label: User pointer to a NUL-terminated string
> +	 *
> +	 * Length cannot be greater than 4096
> +	 */
> +	__u64 label;
> +};
> +
>  /* Definitions for coredump decoding in user space */
>  #define PANFROSTDUMP_MAJOR 1
>  #define PANFROSTDUMP_MINOR 0

Re: [PATCH 3/3] drm/panfrost: show device-wide list of DRM GEM objects over DebugFS

[Boris Brezillon]

On Thu, 24 Apr 2025 03:21:32 +0100
Adrián Larumbe <adrian.larumbe@collabora.com> wrote:

> This change is essentially a Panfrost port of commit a3707f53eb3f
> ("drm/panthor: show device-wide list of DRM GEM objects over DebugFS").
> 
> The DebugFS file is almost the same as in Panthor, minus the GEM object
> usage flags, since Panfrost has no kernel-only BO's.
> 
> Two additional GEM state flags which are displayed but aren't relevant
> to Panthor are 'Purged' and 'Purgeable', since Panfrost implements an
> explicit shrinker and a madvise ioctl to flag objects as reclaimable.
> 
> Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com>
> ---
>  drivers/gpu/drm/panfrost/panfrost_device.c |   4 +
>  drivers/gpu/drm/panfrost/panfrost_device.h |  11 ++
>  drivers/gpu/drm/panfrost/panfrost_drv.c    |  37 ++++++
>  drivers/gpu/drm/panfrost/panfrost_gem.c    | 137 +++++++++++++++++++++
>  drivers/gpu/drm/panfrost/panfrost_gem.h    |  58 +++++++++
>  5 files changed, 247 insertions(+)
> 
> diff --git a/drivers/gpu/drm/panfrost/panfrost_device.c b/drivers/gpu/drm/panfrost/panfrost_device.c
> index a45e4addcc19..7ba140aaf59d 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_device.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_device.c
> @@ -209,6 +209,10 @@ int panfrost_device_init(struct panfrost_device *pfdev)
>  
>  	spin_lock_init(&pfdev->cycle_counter.lock);
>  
> +#ifdef CONFIG_DEBUG_FS
> +	mutex_init(&pfdev->gems.lock);
> +	INIT_LIST_HEAD(&pfdev->gems.node);
> +#endif
>  	err = panfrost_clk_init(pfdev);
>  	if (err) {
>  		dev_err(pfdev->dev, "clk init failed %d\n", err);
> diff --git a/drivers/gpu/drm/panfrost/panfrost_device.h b/drivers/gpu/drm/panfrost/panfrost_device.h
> index ad95f2ed31d9..395272a79306 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_device.h
> +++ b/drivers/gpu/drm/panfrost/panfrost_device.h
> @@ -161,6 +161,17 @@ struct panfrost_device {
>  		atomic_t use_count;
>  		spinlock_t lock;
>  	} cycle_counter;
> +
> +	#ifdef CONFIG_DEBUG_FS

Drop the tab.

> +	/** @gems: Device-wide list of GEM objects owned by at least one file. */
> +	struct {
> +		/** @gems.lock: Protects the device-wide list of GEM objects. */
> +		struct mutex lock;
> +
> +		/** @node: Used to keep track of all the device's DRM objects */
> +		struct list_head node;
> +	} gems;
> +#endif

I would probably also put those in a panfrost_device_debugfs struct.

>  };
>  
>  struct panfrost_mmu {
> diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c b/drivers/gpu/drm/panfrost/panfrost_drv.c
> index b0ab76d67e96..12dd9f311984 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_drv.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_drv.c
> @@ -13,6 +13,7 @@
>  #include <linux/platform_device.h>
>  #include <linux/pm_runtime.h>
>  #include <drm/panfrost_drm.h>
> +#include <drm/drm_debugfs.h>
>  #include <drm/drm_drv.h>
>  #include <drm/drm_ioctl.h>
>  #include <drm/drm_syncobj.h>
> @@ -153,6 +154,8 @@ static int panfrost_ioctl_create_bo(struct drm_device *dev, void *data,
>  		ret = -EINVAL;
>  	}
>  
> +	panfrost_gem_debugfs_init_bo(bo);

This is the only place where you call panfrost_gem_debugfs_init_bo(),
so why not calling panfrost_gem_debugfs_bo_add() at the end of
panfrost_gem_create() instead, and drop the initialised field (and
panfrost_gem_debugfs_init_bo() helper).

> +
>  out:
>  	drm_gem_object_put(&bo->base.base);
>  	return ret;
> @@ -659,6 +662,37 @@ static const struct file_operations panfrost_drm_driver_fops = {
>  	.show_fdinfo = drm_show_fdinfo,
>  };
>  
> +#ifdef CONFIG_DEBUG_FS
> +static int panthor_gems_show(struct seq_file *m, void *data)
> +{
> +	struct drm_info_node *node = m->private;
> +	struct drm_device *dev = node->minor->dev;
> +	struct panfrost_device *pfdev = dev->dev_private;
> +
> +	panfrost_gem_debugfs_print_bos(pfdev, m);
> +
> +	return 0;
> +}
> +
> +static struct drm_info_list panthor_debugfs_list[] = {
> +	{"gems", panthor_gems_show, 0, NULL},
> +};
> +
> +static int panthor_gems_debugfs_init(struct drm_minor *minor)
> +{
> +	drm_debugfs_create_files(panthor_debugfs_list,
> +				 ARRAY_SIZE(panthor_debugfs_list),
> +				 minor->debugfs_root, minor);
> +
> +	return 0;
> +}
> +
> +static void panfrost_debugfs_init(struct drm_minor *minor)
> +{
> +	panthor_gems_debugfs_init(minor);
> +}
> +#endif
> +
>  /*
>   * Panfrost driver version:
>   * - 1.0 - initial interface
> @@ -683,6 +717,9 @@ static const struct drm_driver panfrost_drm_driver = {
>  
>  	.gem_create_object	= panfrost_gem_create_object,
>  	.gem_prime_import_sg_table = panfrost_gem_prime_import_sg_table,
> +#ifdef CONFIG_DEBUG_FS
> +	.debugfs_init = panfrost_debugfs_init,
> +#endif
>  };
>  
>  static int panfrost_probe(struct platform_device *pdev)
> diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.c b/drivers/gpu/drm/panfrost/panfrost_gem.c
> index a7a29974d8b1..8a0fd1abd05c 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_gem.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_gem.c
> @@ -12,6 +12,38 @@
>  #include "panfrost_gem.h"
>  #include "panfrost_mmu.h"
>  
> +#ifdef CONFIG_DEBUG_FS
> +static void panfrost_gem_debugfs_bo_add(struct panfrost_device *ptdev,
> +					struct panfrost_gem_object *bo)
> +{
> +	INIT_LIST_HEAD(&bo->debugfs.node);

There's no point calling INIT_LIST_HEAD() if you're calling
list_add_tail() immediately after.

> +
> +	bo->debugfs.creator.tgid = current->group_leader->pid;
> +	get_task_comm(bo->debugfs.creator.process_name, current->group_leader);
> +
> +	mutex_lock(&ptdev->gems.lock);
> +	list_add_tail(&bo->debugfs.node, &ptdev->gems.node);
> +	mutex_unlock(&ptdev->gems.lock);
> +}
> +
> +static void panfrost_gem_debugfs_bo_rm(struct panfrost_gem_object *bo)
> +{
> +	struct panfrost_device *ptdev = bo->base.base.dev->dev_private;
> +
> +	if (list_empty(&bo->debugfs.node))
> +		return;
> +
> +	mutex_lock(&ptdev->gems.lock);
> +	list_del_init(&bo->debugfs.node);
> +	mutex_unlock(&ptdev->gems.lock);
> +}
> +#else
> +static void panfrost_gem_debugfs_bo_add(struct panfrost_device *ptdev,
> +					struct panfrost_gem_object *bo)
> +{}
> +static void panfrost_gem_debugfs_bo_rm(struct panfrost_gem_object *bo) {}
> +#endif
> +
>  /* Called DRM core on the last userspace/kernel unreference of the
>   * BO.
>   */
> @@ -36,6 +68,7 @@ static void panfrost_gem_free_object(struct drm_gem_object *obj)
>  	 */
>  	WARN_ON_ONCE(!list_empty(&bo->mappings.list));
>  
> +	panfrost_gem_debugfs_bo_rm(bo);
>  	kfree(bo->label.str);
>  	mutex_destroy(&bo->label.lock);
>  
> @@ -266,6 +299,8 @@ struct drm_gem_object *panfrost_gem_create_object(struct drm_device *dev, size_t
>  	obj->base.map_wc = !pfdev->coherent;
>  	mutex_init(&obj->label.lock);
>  
> +	panfrost_gem_debugfs_bo_add(pfdev, obj);
> +
>  	return &obj->base.base;
>  }
>  
> @@ -321,3 +356,105 @@ panfrost_gem_set_label(struct drm_gem_object *obj, const char *label)
>  
>  	kfree(old_label);
>  }
> +
> +#ifdef CONFIG_DEBUG_FS
> +struct gem_size_totals {
> +	size_t size;
> +	size_t resident;
> +	size_t reclaimable;
> +};
> +
> +struct flag_def {
> +	u32 flag;
> +	const char *name;
> +};
> +
> +static void panfrost_gem_debugfs_print_flag_names(struct seq_file *m)
> +{
> +	int len;
> +	int i;
> +
> +	static const struct flag_def gem_state_flags_names[] = {
> +		{PANFROST_DEBUGFS_GEM_STATE_FLAG_IMPORTED, "imported"},
> +		{PANFROST_DEBUGFS_GEM_STATE_FLAG_EXPORTED, "exported"},
> +		{PANFROST_DEBUGFS_GEM_STATE_FLAG_PURGED, "purged"},
> +		{PANFROST_DEBUGFS_GEM_STATE_FLAG_PURGEABLE, "purgeable"},
> +	};
> +
> +	seq_puts(m, "GEM state flags: ");
> +	for (i = 0, len = ARRAY_SIZE(gem_state_flags_names); i < len; i++) {
> +		seq_printf(m, "%s (0x%x)%s", gem_state_flags_names[i].name,
> +			   gem_state_flags_names[i].flag, (i < len - 1) ? ", " : "\n\n");
> +	}
> +}
> +
> +static void panfrost_gem_debugfs_bo_print(struct panfrost_gem_object *bo,
> +					  struct seq_file *m,
> +					  struct gem_size_totals *totals)
> +{
> +	unsigned int refcount = kref_read(&bo->base.base.refcount);
> +	char creator_info[32] = {};
> +	size_t resident_size;
> +	u32 gem_state_flags = 0;
> +
> +	/* Skip BOs being destroyed. */
> +	if (!refcount)
> +		return;
> +
> +	resident_size = bo->base.pages ? bo->base.base.size : 0;
> +
> +	snprintf(creator_info, sizeof(creator_info),
> +		 "%s/%d", bo->debugfs.creator.process_name, bo->debugfs.creator.tgid);
> +	seq_printf(m, "%-32s%-16d%-16d%-16zd%-16zd0x%-16lx",
> +		   creator_info,
> +		   bo->base.base.name,
> +		   refcount,
> +		   bo->base.base.size,
> +		   resident_size,
> +		   drm_vma_node_start(&bo->base.base.vma_node));
> +
> +	if (bo->base.base.import_attach)
> +		gem_state_flags |= PANFROST_DEBUGFS_GEM_STATE_FLAG_IMPORTED;
> +	if (bo->base.base.dma_buf)
> +		gem_state_flags |= PANFROST_DEBUGFS_GEM_STATE_FLAG_EXPORTED;
> +
> +	if (bo->base.madv < 0)
> +		gem_state_flags |= PANFROST_DEBUGFS_GEM_STATE_FLAG_PURGED;
> +	else if (bo->base.madv > 0)
> +		gem_state_flags |= PANFROST_DEBUGFS_GEM_STATE_FLAG_PURGEABLE;
> +
> +	seq_printf(m, "0x%-10x", gem_state_flags);
> +
> +	scoped_guard(mutex, &bo->label.lock) {
> +		seq_printf(m, "%s\n", bo->label.str ? : "");
> +	}
> +
> +	totals->size += bo->base.base.size;
> +	totals->resident += resident_size;
> +	if (bo->base.madv > 0)
> +		totals->reclaimable += resident_size;
> +}
> +
> +void panfrost_gem_debugfs_print_bos(struct panfrost_device *ptdev,
> +				    struct seq_file *m)
> +{
> +	struct gem_size_totals totals = {0};
> +	struct panfrost_gem_object *bo;
> +
> +	panfrost_gem_debugfs_print_flag_names(m);
> +
> +	seq_puts(m, "created-by                      global-name     refcount        size            resident-size   file-offset       state       label\n");
> +	seq_puts(m, "-----------------------------------------------------------------------------------------------------------------------------------\n");
> +
> +	scoped_guard(mutex, &ptdev->gems.lock) {
> +		list_for_each_entry(bo, &ptdev->gems.node, debugfs.node) {
> +			if (bo->debugfs.initialised)
> +				panfrost_gem_debugfs_bo_print(bo, m, &totals);
> +		}
> +	}
> +
> +	seq_puts(m, "===================================================================================================================================\n");
> +	seq_printf(m, "Total size: %zd, Total resident: %zd, Total reclaimable: %zd\n",
> +		   totals.size, totals.resident, totals.reclaimable);
> +}
> +#endif
> diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.h b/drivers/gpu/drm/panfrost/panfrost_gem.h
> index 842e025b9bdc..bc60e0d74da9 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_gem.h
> +++ b/drivers/gpu/drm/panfrost/panfrost_gem.h
> @@ -8,9 +8,50 @@
>  #include <drm/drm_mm.h>
>  
>  struct panfrost_mmu;
> +struct panfrost_device;
>  
>  #define PANFROST_BO_LABEL_MAXLEN	4096
>  
> +enum panfrost_debugfs_gem_state_flags {
> +	/** @PANFROST_DEBUGFS_GEM_STATE_FLAG_IMPORTED: GEM BO is PRIME imported. */
> +	PANFROST_DEBUGFS_GEM_STATE_FLAG_IMPORTED = BIT(0),
> +
> +	/** @PANFROST_DEBUGFS_GEM_STATE_FLAG_EXPORTED: GEM BO is PRIME exported. */
> +	PANFROST_DEBUGFS_GEM_STATE_FLAG_EXPORTED = BIT(1),
> +
> +	/** @PANFROST_DEBUGFS_GEM_STATE_FLAG_PURGED: GEM BO was reclaimed by the shrinker. */
> +	PANFROST_DEBUGFS_GEM_STATE_FLAG_PURGED = BIT(2),
> +
> +	/**
> +	 * @PANFROST_DEBUGFS_GEM_STATE_FLAG_PURGEABLE: GEM BO pages were marked as no longer
> +	 * needed by UM and can be reclaimed by the shrinker.
> +	 */
> +	PANFROST_DEBUGFS_GEM_STATE_FLAG_PURGEABLE = BIT(3),
> +};
> +
> +/**
> + * struct panfrost_gem_debugfs - GEM object's DebugFS list information
> + */
> +struct panfrost_gem_debugfs {
> +	/**
> +	 * @node: Node used to insert the object in the device-wide list of
> +	 * GEM objects, to display information about it through a DebugFS file.
> +	 */
> +	struct list_head node;
> +
> +	/** @creator: Information about the UM process which created the GEM. */
> +	struct {
> +		/** @creator.process_name: Group leader name in owning thread's process */
> +		char process_name[TASK_COMM_LEN];
> +
> +		/** @creator.tgid: PID of the thread's group leader within its process */
> +		pid_t tgid;
> +	} creator;
> +
> +	/** @initialised: GEM object is ready to be displayed in DebugFS file. */
> +	bool initialised;
> +};
> +
>  struct panfrost_gem_object {
>  	struct drm_gem_shmem_object base;
>  	struct sg_table *sgts;
> @@ -59,6 +100,10 @@ struct panfrost_gem_object {
>  
>  	bool noexec		:1;
>  	bool is_heap		:1;
> +
> +#ifdef CONFIG_DEBUG_FS
> +	struct panfrost_gem_debugfs debugfs;
> +#endif
>  };
>  
>  struct panfrost_gem_mapping {
> @@ -107,4 +152,17 @@ void panfrost_gem_shrinker_cleanup(struct drm_device *dev);
>  
>  void panfrost_gem_set_label(struct drm_gem_object *obj, const char *label);
>  
> +#ifdef CONFIG_DEBUG_FS
> +void panfrost_gem_debugfs_print_bos(struct panfrost_device *pfdev,
> +				    struct seq_file *m);
> +static inline void
> +panfrost_gem_debugfs_init_bo(struct panfrost_gem_object *bo)
> +{
> +	bo->debugfs.initialised = true;
> +}
> +#else
> +static inline void
> +panfrost_gem_debugfs_init_bo(struct panfrost_gem_object *bo) {};
> +#endif
> +
>  #endif /* __PANFROST_GEM_H__ */

Re: [PATCH 1/3] drm/panfrost: Add BO labelling to Panfrost

[Adrián Larumbe]

On 06.05.2025 08:54, Boris Brezillon wrote:
> On Thu, 24 Apr 2025 03:21:30 +0100
> Adrián Larumbe <adrian.larumbe@collabora.com> wrote:
>
> > Unlike in Panthor, from where this change is based on, there is no need
> > to support tagging of BO's other than UM-exposed ones, so all strings
> > can be freed with kfree().
> >
> > This commit is done in preparation of a following one that will allow
> > UM to set BO labels through a new ioctl().
> >
> > Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com>
> > ---
> >  drivers/gpu/drm/panfrost/panfrost_gem.c | 19 +++++++++++++++++++
> >  drivers/gpu/drm/panfrost/panfrost_gem.h | 16 ++++++++++++++++
> >  2 files changed, 35 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.c b/drivers/gpu/drm/panfrost/panfrost_gem.c
> > index 963f04ba2de6..a7a29974d8b1 100644
> > --- a/drivers/gpu/drm/panfrost/panfrost_gem.c
> > +++ b/drivers/gpu/drm/panfrost/panfrost_gem.c
> > @@ -1,6 +1,7 @@
> >  // SPDX-License-Identifier: GPL-2.0
> >  /* Copyright 2019 Linaro, Ltd, Rob Herring <robh@kernel.org> */
> >
> > +#include <linux/cleanup.h>
> >  #include <linux/err.h>
> >  #include <linux/slab.h>
> >  #include <linux/dma-buf.h>
> > @@ -35,6 +36,9 @@ static void panfrost_gem_free_object(struct drm_gem_object *obj)
> >  	 */
> >  	WARN_ON_ONCE(!list_empty(&bo->mappings.list));
> >
> > +	kfree(bo->label.str);
> > +	mutex_destroy(&bo->label.lock);
> > +
> >  	if (bo->sgts) {
> >  		int i;
> >  		int n_sgt = bo->base.base.size / SZ_2M;
> > @@ -260,6 +264,7 @@ struct drm_gem_object *panfrost_gem_create_object(struct drm_device *dev, size_t
> >  	mutex_init(&obj->mappings.lock);
> >  	obj->base.base.funcs = &panfrost_gem_funcs;
> >  	obj->base.map_wc = !pfdev->coherent;
> > +	mutex_init(&obj->label.lock);
> >
> >  	return &obj->base.base;
> >  }
> > @@ -302,3 +307,17 @@ panfrost_gem_prime_import_sg_table(struct drm_device *dev,
> >
> >  	return obj;
> >  }
> > +
> > +void
> > +panfrost_gem_set_label(struct drm_gem_object *obj, const char *label)
> > +{
> > +	struct panfrost_gem_object *bo = to_panfrost_bo(obj);
> > +	const char *old_label;
> > +
> > +	scoped_guard(mutex, &bo->label.lock) {
> > +		old_label = bo->label.str;
> > +		bo->label.str = label;
> > +	}
> > +
> > +	kfree(old_label);
> > +}
> > diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.h b/drivers/gpu/drm/panfrost/panfrost_gem.h
> > index 7516b7ecf7fe..c0be2934f229 100644
> > --- a/drivers/gpu/drm/panfrost/panfrost_gem.h
> > +++ b/drivers/gpu/drm/panfrost/panfrost_gem.h
> > @@ -41,6 +41,20 @@ struct panfrost_gem_object {
> >  	 */
> >  	size_t heap_rss_size;
> >
> > +	/**
> > +	 * @label: BO tagging fields. The label can be assigned within the
> > +	 * driver itself or through a specific IOCTL.
> > +	 */
> > +	struct {
> > +		/**
> > +		 * @label.str: Pointer to NULL-terminated string,
> > +		 */
> > +		const char *str;
> > +
> > +		/** @lock.str: Protects access to the @label.str field. */
> > +		struct mutex lock;
> > +	} label;
>
> Can we do as we did in panthor, and put those fields in the debugfs
> field.

BO labelling fields must be present outside of DebugFS builds.

> +
>  	bool noexec		:1;
>  	bool is_heap		:1;
>  };
> @@ -89,4 +103,6 @@ void panfrost_gem_teardown_mappings_locked(struct panfrost_gem_object *bo);
>  int panfrost_gem_shrinker_init(struct drm_device *dev);
>  void panfrost_gem_shrinker_cleanup(struct drm_device *dev);
>
> +void panfrost_gem_set_label(struct drm_gem_object *obj, const char *label);
> +
>  #endif /* __PANFROST_GEM_H__ */


Adrian Larumbe

Re: [PATCH 1/3] drm/panfrost: Add BO labelling to Panfrost

[Steven Price]

On 24/04/2025 03:21, Adrián Larumbe wrote:
> Unlike in Panthor, from where this change is based on, there is no need
> to support tagging of BO's other than UM-exposed ones, so all strings
> can be freed with kfree().
> 
> This commit is done in preparation of a following one that will allow
> UM to set BO labels through a new ioctl().
> 
> Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com>

Reviewed-by: Steven Price <steven.price@arm.com>

But one comment below

> ---
>  drivers/gpu/drm/panfrost/panfrost_gem.c | 19 +++++++++++++++++++
>  drivers/gpu/drm/panfrost/panfrost_gem.h | 16 ++++++++++++++++
>  2 files changed, 35 insertions(+)
> 
> diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.c b/drivers/gpu/drm/panfrost/panfrost_gem.c
> index 963f04ba2de6..a7a29974d8b1 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_gem.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_gem.c
> @@ -1,6 +1,7 @@
>  // SPDX-License-Identifier: GPL-2.0
>  /* Copyright 2019 Linaro, Ltd, Rob Herring <robh@kernel.org> */
>  
> +#include <linux/cleanup.h>
>  #include <linux/err.h>
>  #include <linux/slab.h>
>  #include <linux/dma-buf.h>
> @@ -35,6 +36,9 @@ static void panfrost_gem_free_object(struct drm_gem_object *obj)
>  	 */
>  	WARN_ON_ONCE(!list_empty(&bo->mappings.list));
>  
> +	kfree(bo->label.str);
> +	mutex_destroy(&bo->label.lock);
> +
>  	if (bo->sgts) {
>  		int i;
>  		int n_sgt = bo->base.base.size / SZ_2M;
> @@ -260,6 +264,7 @@ struct drm_gem_object *panfrost_gem_create_object(struct drm_device *dev, size_t
>  	mutex_init(&obj->mappings.lock);
>  	obj->base.base.funcs = &panfrost_gem_funcs;
>  	obj->base.map_wc = !pfdev->coherent;
> +	mutex_init(&obj->label.lock);
>  
>  	return &obj->base.base;
>  }
> @@ -302,3 +307,17 @@ panfrost_gem_prime_import_sg_table(struct drm_device *dev,
>  
>  	return obj;
>  }
> +
> +void
> +panfrost_gem_set_label(struct drm_gem_object *obj, const char *label)
> +{
> +	struct panfrost_gem_object *bo = to_panfrost_bo(obj);
> +	const char *old_label;
> +
> +	scoped_guard(mutex, &bo->label.lock) {
> +		old_label = bo->label.str;
> +		bo->label.str = label;
> +	}
> +
> +	kfree(old_label);
> +}
> diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.h b/drivers/gpu/drm/panfrost/panfrost_gem.h
> index 7516b7ecf7fe..c0be2934f229 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_gem.h
> +++ b/drivers/gpu/drm/panfrost/panfrost_gem.h
> @@ -41,6 +41,20 @@ struct panfrost_gem_object {
>  	 */
>  	size_t heap_rss_size;
>  
> +	/**
> +	 * @label: BO tagging fields. The label can be assigned within the
> +	 * driver itself or through a specific IOCTL.

From the commit message (about the use of kfree()) I assume we are not
expecting this to be assigned "within the driver itself"?

Thanks,
Steve

> +	 */
> +	struct {
> +		/**
> +		 * @label.str: Pointer to NULL-terminated string,
> +		 */
> +		const char *str;
> +
> +		/** @lock.str: Protects access to the @label.str field. */
> +		struct mutex lock;
> +	} label;
> +
>  	bool noexec		:1;
>  	bool is_heap		:1;
>  };
> @@ -89,4 +103,6 @@ void panfrost_gem_teardown_mappings_locked(struct panfrost_gem_object *bo);
>  int panfrost_gem_shrinker_init(struct drm_device *dev);
>  void panfrost_gem_shrinker_cleanup(struct drm_device *dev);
>  
> +void panfrost_gem_set_label(struct drm_gem_object *obj, const char *label);
> +
>  #endif /* __PANFROST_GEM_H__ */

Re: [PATCH 2/3] drm/panfrost: Add driver IOCTL for setting BO labels

[Steven Price]

On 24/04/2025 03:21, Adrián Larumbe wrote:
> Allow UM to label a BO for which it possesses a DRM handle.
> 
> Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com>

Minor comments below, but otherwise:

Reviewed-by: Steven Price <steven.price@arm.com>

> ---
>  drivers/gpu/drm/panfrost/panfrost_drv.c | 44 ++++++++++++++++++++++++-
>  drivers/gpu/drm/panfrost/panfrost_gem.h |  2 ++
>  include/uapi/drm/panfrost_drm.h         | 20 +++++++++++
>  3 files changed, 65 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c b/drivers/gpu/drm/panfrost/panfrost_drv.c
> index b87f83e94eda..b0ab76d67e96 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_drv.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_drv.c
> @@ -495,6 +495,46 @@ static int panfrost_ioctl_madvise(struct drm_device *dev, void *data,
>  	return ret;
>  }
>  
> +static int panfrost_ioctl_set_label_bo(struct drm_device *ddev, void *data,
> +				       struct drm_file *file)
> +{
> +	struct drm_panfrost_set_label_bo *args = data;
> +	struct drm_gem_object *obj;
> +	const char *label = NULL;
> +	int ret = 0;
> +
> +	if (args->pad)
> +		return -EINVAL;
> +
> +	obj = drm_gem_object_lookup(file, args->handle);
> +	if (!obj)
> +		return -ENOENT;
> +
> +	if (args->label) {
> +		label = strndup_user((const char __user *)(uintptr_t)args->label,

Use u64_to_user_ptr()

> +				     PANFROST_BO_LABEL_MAXLEN);
> +		if (IS_ERR(label)) {
> +			ret = PTR_ERR(label);
> +			if (ret == -EINVAL)
> +				ret = -E2BIG;
> +			goto err_put_obj;
> +		}
> +	}
> +
> +	/*
> +	 * We treat passing a label of length 0 and passing a NULL label
> +	 * differently, because even though they might seem conceptually
> +	 * similar, future uses of the BO label might expect a different
> +	 * behaviour in each case.
> +	 */
> +	panfrost_gem_set_label(obj, label);
> +
> +err_put_obj:
> +	drm_gem_object_put(obj);
> +
> +	return ret;
> +}
> +
>  int panfrost_unstable_ioctl_check(void)
>  {
>  	if (!unstable_ioctls)
> @@ -561,6 +601,7 @@ static const struct drm_ioctl_desc panfrost_drm_driver_ioctls[] = {
>  	PANFROST_IOCTL(PERFCNT_ENABLE,	perfcnt_enable,	DRM_RENDER_ALLOW),
>  	PANFROST_IOCTL(PERFCNT_DUMP,	perfcnt_dump,	DRM_RENDER_ALLOW),
>  	PANFROST_IOCTL(MADVISE,		madvise,	DRM_RENDER_ALLOW),
> +	PANFROST_IOCTL(SET_LABEL_BO,	set_label_bo,	DRM_RENDER_ALLOW),
>  };
>  
>  static void panfrost_gpu_show_fdinfo(struct panfrost_device *pfdev,
> @@ -625,6 +666,7 @@ static const struct file_operations panfrost_drm_driver_fops = {
>   * - 1.2 - adds AFBC_FEATURES query
>   * - 1.3 - adds JD_REQ_CYCLE_COUNT job requirement for SUBMIT
>   *       - adds SYSTEM_TIMESTAMP and SYSTEM_TIMESTAMP_FREQUENCY queries
> + * - 1.4 - adds SET_LABEL_BO
>   */
>  static const struct drm_driver panfrost_drm_driver = {
>  	.driver_features	= DRIVER_RENDER | DRIVER_GEM | DRIVER_SYNCOBJ,
> @@ -637,7 +679,7 @@ static const struct drm_driver panfrost_drm_driver = {
>  	.name			= "panfrost",
>  	.desc			= "panfrost DRM",
>  	.major			= 1,
> -	.minor			= 3,
> +	.minor			= 4,
>  
>  	.gem_create_object	= panfrost_gem_create_object,
>  	.gem_prime_import_sg_table = panfrost_gem_prime_import_sg_table,
> diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.h b/drivers/gpu/drm/panfrost/panfrost_gem.h
> index c0be2934f229..842e025b9bdc 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_gem.h
> +++ b/drivers/gpu/drm/panfrost/panfrost_gem.h
> @@ -9,6 +9,8 @@
>  
>  struct panfrost_mmu;
>  
> +#define PANFROST_BO_LABEL_MAXLEN	4096
> +
>  struct panfrost_gem_object {
>  	struct drm_gem_shmem_object base;
>  	struct sg_table *sgts;
> diff --git a/include/uapi/drm/panfrost_drm.h b/include/uapi/drm/panfrost_drm.h
> index 568724be6628..b0445c5e514d 100644
> --- a/include/uapi/drm/panfrost_drm.h
> +++ b/include/uapi/drm/panfrost_drm.h
> @@ -21,6 +21,7 @@ extern "C" {
>  #define DRM_PANFROST_PERFCNT_ENABLE		0x06
>  #define DRM_PANFROST_PERFCNT_DUMP		0x07
>  #define DRM_PANFROST_MADVISE			0x08
> +#define DRM_PANFROST_SET_LABEL_BO		0x09
>  
>  #define DRM_IOCTL_PANFROST_SUBMIT		DRM_IOW(DRM_COMMAND_BASE + DRM_PANFROST_SUBMIT, struct drm_panfrost_submit)
>  #define DRM_IOCTL_PANFROST_WAIT_BO		DRM_IOW(DRM_COMMAND_BASE + DRM_PANFROST_WAIT_BO, struct drm_panfrost_wait_bo)
> @@ -29,6 +30,7 @@ extern "C" {
>  #define DRM_IOCTL_PANFROST_GET_PARAM		DRM_IOWR(DRM_COMMAND_BASE + DRM_PANFROST_GET_PARAM, struct drm_panfrost_get_param)
>  #define DRM_IOCTL_PANFROST_GET_BO_OFFSET	DRM_IOWR(DRM_COMMAND_BASE + DRM_PANFROST_GET_BO_OFFSET, struct drm_panfrost_get_bo_offset)
>  #define DRM_IOCTL_PANFROST_MADVISE		DRM_IOWR(DRM_COMMAND_BASE + DRM_PANFROST_MADVISE, struct drm_panfrost_madvise)
> +#define DRM_IOCTL_PANFROST_SET_LABEL_BO		DRM_IOWR(DRM_COMMAND_BASE + DRM_PANFROST_SET_LABEL_BO, struct drm_panfrost_set_label_bo)
>  
>  /*
>   * Unstable ioctl(s): only exposed when the unsafe unstable_ioctls module
> @@ -227,6 +229,24 @@ struct drm_panfrost_madvise {
>  	__u32 retained;       /* out, whether backing store still exists */
>  };
>  
> +/**
> + * struct drm_panfrost_set_label_bo - ioctl argument for labelling Panfrost BOs.
> + */
> +struct drm_panfrost_set_label_bo {
> +	/** @handle: Handle of the buffer object to label. */
> +	__u32 handle;
> +
> +	/**  @pad: MBZ. */
> +	__u32 pad;
> +
> +	/**
> +	 * @label: User pointer to a NUL-terminated string
> +	 *
> +	 * Length cannot be greater than 4096

NULL is permitted and means clear the label.

Thanks,
Steve

> +	 */
> +	__u64 label;
> +};
> +
>  /* Definitions for coredump decoding in user space */
>  #define PANFROSTDUMP_MAJOR 1
>  #define PANFROSTDUMP_MINOR 0

Re: [PATCH 3/3] drm/panfrost: show device-wide list of DRM GEM objects over DebugFS

[Adrián Larumbe]

On 06.05.2025 09:04, Boris Brezillon wrote:
> On Thu, 24 Apr 2025 03:21:32 +0100
> Adrián Larumbe <adrian.larumbe@collabora.com> wrote:
>
> > This change is essentially a Panfrost port of commit a3707f53eb3f
> > ("drm/panthor: show device-wide list of DRM GEM objects over DebugFS").
> >
> > The DebugFS file is almost the same as in Panthor, minus the GEM object
> > usage flags, since Panfrost has no kernel-only BO's.
> >
> > Two additional GEM state flags which are displayed but aren't relevant
> > to Panthor are 'Purged' and 'Purgeable', since Panfrost implements an
> > explicit shrinker and a madvise ioctl to flag objects as reclaimable.
> >
> > Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com>
> > ---
> >  drivers/gpu/drm/panfrost/panfrost_device.c |   4 +
> >  drivers/gpu/drm/panfrost/panfrost_device.h |  11 ++
> >  drivers/gpu/drm/panfrost/panfrost_drv.c    |  37 ++++++
> >  drivers/gpu/drm/panfrost/panfrost_gem.c    | 137 +++++++++++++++++++++
> >  drivers/gpu/drm/panfrost/panfrost_gem.h    |  58 +++++++++
> >  5 files changed, 247 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/panfrost/panfrost_device.c b/drivers/gpu/drm/panfrost/panfrost_device.c
> > index a45e4addcc19..7ba140aaf59d 100644
> > --- a/drivers/gpu/drm/panfrost/panfrost_device.c
> > +++ b/drivers/gpu/drm/panfrost/panfrost_device.c
> > @@ -209,6 +209,10 @@ int panfrost_device_init(struct panfrost_device *pfdev)
> >
> >  	spin_lock_init(&pfdev->cycle_counter.lock);
> >
> > +#ifdef CONFIG_DEBUG_FS
> > +	mutex_init(&pfdev->gems.lock);
> > +	INIT_LIST_HEAD(&pfdev->gems.node);
> > +#endif
> >  	err = panfrost_clk_init(pfdev);
> >  	if (err) {
> >  		dev_err(pfdev->dev, "clk init failed %d\n", err);
> > diff --git a/drivers/gpu/drm/panfrost/panfrost_device.h b/drivers/gpu/drm/panfrost/panfrost_device.h
> > index ad95f2ed31d9..395272a79306 100644
> > --- a/drivers/gpu/drm/panfrost/panfrost_device.h
> > +++ b/drivers/gpu/drm/panfrost/panfrost_device.h
> > @@ -161,6 +161,17 @@ struct panfrost_device {
> >  		atomic_t use_count;
> >  		spinlock_t lock;
> >  	} cycle_counter;
> > +
> > +	#ifdef CONFIG_DEBUG_FS
>
> Drop the tab.

Done.
>
> > +	/** @gems: Device-wide list of GEM objects owned by at least one file. */
> > +	struct {
> > +		/** @gems.lock: Protects the device-wide list of GEM objects. */
> > +		struct mutex lock;
> > +
> > +		/** @node: Used to keep track of all the device's DRM objects */
> > +		struct list_head node;
> > +	} gems;
> > +#endif
>
> I would probably also put those in a panfrost_device_debugfs struct.
>  };

I think in the case of Panthor we left them outside of a specific structure, but I think it's a good idea.

> >  struct panfrost_mmu {
> > diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c b/drivers/gpu/drm/panfrost/panfrost_drv.c
> > index b0ab76d67e96..12dd9f311984 100644
> > --- a/drivers/gpu/drm/panfrost/panfrost_drv.c
> > +++ b/drivers/gpu/drm/panfrost/panfrost_drv.c
> > @@ -13,6 +13,7 @@
> >  #include <linux/platform_device.h>
> >  #include <linux/pm_runtime.h>
> >  #include <drm/panfrost_drm.h>
> > +#include <drm/drm_debugfs.h>
> >  #include <drm/drm_drv.h>
> >  #include <drm/drm_ioctl.h>
> >  #include <drm/drm_syncobj.h>
> > @@ -153,6 +154,8 @@ static int panfrost_ioctl_create_bo(struct drm_device *dev, void *data,
> >  		ret = -EINVAL;
> >  	}
> >
> > +	panfrost_gem_debugfs_init_bo(bo);
> >
> > This is the only place where you call panfrost_gem_debugfs_init_bo(),
> > so why not calling panfrost_gem_debugfs_bo_add() at the end of
> > panfrost_gem_create() instead, and drop the initialised field (and
> > panfrost_gem_debugfs_init_bo() helper).

Done.

> > +
> >  out:
> >  	drm_gem_object_put(&bo->base.base);
> >  	return ret;
> > @@ -659,6 +662,37 @@ static const struct file_operations panfrost_drm_driver_fops = {
> >  	.show_fdinfo = drm_show_fdinfo,
> >  };
> >
> > +#ifdef CONFIG_DEBUG_FS
> > +static int panthor_gems_show(struct seq_file *m, void *data)
> > +{
> > +	struct drm_info_node *node = m->private;
> > +	struct drm_device *dev = node->minor->dev;
> > +	struct panfrost_device *pfdev = dev->dev_private;
> > +
> > +	panfrost_gem_debugfs_print_bos(pfdev, m);
> > +
> > +	return 0;
> > +}
> > +
> > +static struct drm_info_list panthor_debugfs_list[] = {
> > +	{"gems", panthor_gems_show, 0, NULL},
> > +};
> > +
> > +static int panthor_gems_debugfs_init(struct drm_minor *minor)
> > +{
> > +	drm_debugfs_create_files(panthor_debugfs_list,
> > +				 ARRAY_SIZE(panthor_debugfs_list),
> > +				 minor->debugfs_root, minor);
> > +
> > +	return 0;
> > +}
> > +
> > +static void panfrost_debugfs_init(struct drm_minor *minor)
> > +{
> > +	panthor_gems_debugfs_init(minor);
> > +}
> > +#endif
> > +
> >  /*
> >   * Panfrost driver version:
> >   * - 1.0 - initial interface
> > @@ -683,6 +717,9 @@ static const struct drm_driver panfrost_drm_driver = {
> >
> >  	.gem_create_object	= panfrost_gem_create_object,
> >  	.gem_prime_import_sg_table = panfrost_gem_prime_import_sg_table,
> > +#ifdef CONFIG_DEBUG_FS
> > +	.debugfs_init = panfrost_debugfs_init,
> > +#endif
> >  };
> >
> >  static int panfrost_probe(struct platform_device *pdev)
> > diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.c b/drivers/gpu/drm/panfrost/panfrost_gem.c
> > index a7a29974d8b1..8a0fd1abd05c 100644
> > --- a/drivers/gpu/drm/panfrost/panfrost_gem.c
> > +++ b/drivers/gpu/drm/panfrost/panfrost_gem.c
> > @@ -12,6 +12,38 @@
> >  #include "panfrost_gem.h"
> >  #include "panfrost_mmu.h"
> >
> > +#ifdef CONFIG_DEBUG_FS
> > +static void panfrost_gem_debugfs_bo_add(struct panfrost_device *ptdev,
> > +					struct panfrost_gem_object *bo)
> > +{
> > +	INIT_LIST_HEAD(&bo->debugfs.node);
>
> There's no point calling INIT_LIST_HEAD() if you're calling
> list_add_tail() immediately after.

Deleted.

> > +
> > +	bo->debugfs.creator.tgid = current->group_leader->pid;
> > +	get_task_comm(bo->debugfs.creator.process_name, current->group_leader);
> > +
> > +	mutex_lock(&ptdev->gems.lock);
> > +	list_add_tail(&bo->debugfs.node, &ptdev->gems.node);
> > +	mutex_unlock(&ptdev->gems.lock);
> > +}
> > +
> > +static void panfrost_gem_debugfs_bo_rm(struct panfrost_gem_object *bo)
> > +{
> > +	struct panfrost_device *ptdev = bo->base.base.dev->dev_private;
> > +
> > +	if (list_empty(&bo->debugfs.node))
> > +		return;
> > +
> > +	mutex_lock(&ptdev->gems.lock);
> > +	list_del_init(&bo->debugfs.node);
> > +	mutex_unlock(&ptdev->gems.lock);
> > +}
> > +#else
> > +static void panfrost_gem_debugfs_bo_add(struct panfrost_device *ptdev,
> > +					struct panfrost_gem_object *bo)
> > +{}
> > +static void panfrost_gem_debugfs_bo_rm(struct panfrost_gem_object *bo) {}
> > +#endif
> > +
> >  /* Called DRM core on the last userspace/kernel unreference of the
> >   * BO.
> >   */
> > @@ -36,6 +68,7 @@ static void panfrost_gem_free_object(struct drm_gem_object *obj)
> >  	 */
> >  	WARN_ON_ONCE(!list_empty(&bo->mappings.list));
> >
> > +	panfrost_gem_debugfs_bo_rm(bo);
> >  	kfree(bo->label.str);
> >  	mutex_destroy(&bo->label.lock);
> >
> > @@ -266,6 +299,8 @@ struct drm_gem_object *panfrost_gem_create_object(struct drm_device *dev, size_t
> >  	obj->base.map_wc = !pfdev->coherent;
> >  	mutex_init(&obj->label.lock);
> >
> > +	panfrost_gem_debugfs_bo_add(pfdev, obj);
> > +
> >  	return &obj->base.base;
> >  }
> >
> > @@ -321,3 +356,105 @@ panfrost_gem_set_label(struct drm_gem_object *obj, const char *label)
> >
> >  	kfree(old_label);
> >  }
> > +
> > +#ifdef CONFIG_DEBUG_FS
> > +struct gem_size_totals {
> > +	size_t size;
> > +	size_t resident;
> > +	size_t reclaimable;
> > +};
> > +
> > +struct flag_def {
> > +	u32 flag;
> > +	const char *name;
> > +};
> > +
> > +static void panfrost_gem_debugfs_print_flag_names(struct seq_file *m)
> > +{
> > +	int len;
> > +	int i;
> > +
> > +	static const struct flag_def gem_state_flags_names[] = {
> > +		{PANFROST_DEBUGFS_GEM_STATE_FLAG_IMPORTED, "imported"},
> > +		{PANFROST_DEBUGFS_GEM_STATE_FLAG_EXPORTED, "exported"},
> > +		{PANFROST_DEBUGFS_GEM_STATE_FLAG_PURGED, "purged"},
> > +		{PANFROST_DEBUGFS_GEM_STATE_FLAG_PURGEABLE, "purgeable"},
> > +	};
> > +
> > +	seq_puts(m, "GEM state flags: ");
> > +	for (i = 0, len = ARRAY_SIZE(gem_state_flags_names); i < len; i++) {
> > +		seq_printf(m, "%s (0x%x)%s", gem_state_flags_names[i].name,
> > +			   gem_state_flags_names[i].flag, (i < len - 1) ? ", " : "\n\n");
> > +	}
> > +}
> > +
> > +static void panfrost_gem_debugfs_bo_print(struct panfrost_gem_object *bo,
> > +					  struct seq_file *m,
> > +					  struct gem_size_totals *totals)
> > +{
> > +	unsigned int refcount = kref_read(&bo->base.base.refcount);
> > +	char creator_info[32] = {};
> > +	size_t resident_size;
> > +	u32 gem_state_flags = 0;
> > +
> > +	/* Skip BOs being destroyed. */
> > +	if (!refcount)
> > +		return;
> > +
> > +	resident_size = bo->base.pages ? bo->base.base.size : 0;
> > +
> > +	snprintf(creator_info, sizeof(creator_info),
> > +		 "%s/%d", bo->debugfs.creator.process_name, bo->debugfs.creator.tgid);
> > +	seq_printf(m, "%-32s%-16d%-16d%-16zd%-16zd0x%-16lx",
> > +		   creator_info,
> > +		   bo->base.base.name,
> > +		   refcount,
> > +		   bo->base.base.size,
> > +		   resident_size,
> > +		   drm_vma_node_start(&bo->base.base.vma_node));
> > +
> > +	if (bo->base.base.import_attach)
> > +		gem_state_flags |= PANFROST_DEBUGFS_GEM_STATE_FLAG_IMPORTED;
> > +	if (bo->base.base.dma_buf)
> > +		gem_state_flags |= PANFROST_DEBUGFS_GEM_STATE_FLAG_EXPORTED;
> > +
> > +	if (bo->base.madv < 0)
> > +		gem_state_flags |= PANFROST_DEBUGFS_GEM_STATE_FLAG_PURGED;
> > +	else if (bo->base.madv > 0)
> > +		gem_state_flags |= PANFROST_DEBUGFS_GEM_STATE_FLAG_PURGEABLE;
> > +
> > +	seq_printf(m, "0x%-10x", gem_state_flags);
> > +
> > +	scoped_guard(mutex, &bo->label.lock) {
> > +		seq_printf(m, "%s\n", bo->label.str ? : "");
> > +	}
> > +
> > +	totals->size += bo->base.base.size;
> > +	totals->resident += resident_size;
> > +	if (bo->base.madv > 0)
> > +		totals->reclaimable += resident_size;
> > +}
> > +
> > +void panfrost_gem_debugfs_print_bos(struct panfrost_device *ptdev,
> > +				    struct seq_file *m)
> > +{
> > +	struct gem_size_totals totals = {0};
> > +	struct panfrost_gem_object *bo;
> > +
> > +	panfrost_gem_debugfs_print_flag_names(m);
> > +
> > +	seq_puts(m, "created-by                      global-name     refcount        size            resident-size   file-offset       state       label\n");
> > +	seq_puts(m, "-----------------------------------------------------------------------------------------------------------------------------------\n");
> > +
> > +	scoped_guard(mutex, &ptdev->gems.lock) {
> > +		list_for_each_entry(bo, &ptdev->gems.node, debugfs.node) {
> > +			if (bo->debugfs.initialised)
> > +				panfrost_gem_debugfs_bo_print(bo, m, &totals);
> > +		}
> > +	}
> > +
> > +	seq_puts(m, "===================================================================================================================================\n");
> > +	seq_printf(m, "Total size: %zd, Total resident: %zd, Total reclaimable: %zd\n",
> > +		   totals.size, totals.resident, totals.reclaimable);
> > +}
> > +#endif
> > diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.h b/drivers/gpu/drm/panfrost/panfrost_gem.h
> > index 842e025b9bdc..bc60e0d74da9 100644
> > --- a/drivers/gpu/drm/panfrost/panfrost_gem.h
> > +++ b/drivers/gpu/drm/panfrost/panfrost_gem.h
> > @@ -8,9 +8,50 @@
> >  #include <drm/drm_mm.h>
> >
> >  struct panfrost_mmu;
> > +struct panfrost_device;
> >
> >  #define PANFROST_BO_LABEL_MAXLEN	4096
> >
> > +enum panfrost_debugfs_gem_state_flags {
> > +	/** @PANFROST_DEBUGFS_GEM_STATE_FLAG_IMPORTED: GEM BO is PRIME imported. */
> > +	PANFROST_DEBUGFS_GEM_STATE_FLAG_IMPORTED = BIT(0),
> > +
> > +	/** @PANFROST_DEBUGFS_GEM_STATE_FLAG_EXPORTED: GEM BO is PRIME exported. */
> > +	PANFROST_DEBUGFS_GEM_STATE_FLAG_EXPORTED = BIT(1),
> > +
> > +	/** @PANFROST_DEBUGFS_GEM_STATE_FLAG_PURGED: GEM BO was reclaimed by the shrinker. */
> > +	PANFROST_DEBUGFS_GEM_STATE_FLAG_PURGED = BIT(2),
> > +
> > +	/**
> > +	 * @PANFROST_DEBUGFS_GEM_STATE_FLAG_PURGEABLE: GEM BO pages were marked as no longer
> > +	 * needed by UM and can be reclaimed by the shrinker.
> > +	 */
> > +	PANFROST_DEBUGFS_GEM_STATE_FLAG_PURGEABLE = BIT(3),
> > +};
> > +
> > +/**
> > + * struct panfrost_gem_debugfs - GEM object's DebugFS list information
> > + */
> > +struct panfrost_gem_debugfs {
> > +	/**
> > +	 * @node: Node used to insert the object in the device-wide list of
> > +	 * GEM objects, to display information about it through a DebugFS file.
> > +	 */
> > +	struct list_head node;
> > +
> > +	/** @creator: Information about the UM process which created the GEM. */
> > +	struct {
> > +		/** @creator.process_name: Group leader name in owning thread's process */
> > +		char process_name[TASK_COMM_LEN];
> > +
> > +		/** @creator.tgid: PID of the thread's group leader within its process */
> > +		pid_t tgid;
> > +	} creator;
> > +
> > +	/** @initialised: GEM object is ready to be displayed in DebugFS file. */
> > +	bool initialised;
> > +};
> > +
> >  struct panfrost_gem_object {
> >  	struct drm_gem_shmem_object base;
> >  	struct sg_table *sgts;
> > @@ -59,6 +100,10 @@ struct panfrost_gem_object {
> >
> >  	bool noexec		:1;
> >  	bool is_heap		:1;
> > +
> > +#ifdef CONFIG_DEBUG_FS
> > +	struct panfrost_gem_debugfs debugfs;
> > +#endif
> >  };
> >
> >  struct panfrost_gem_mapping {
> > @@ -107,4 +152,17 @@ void panfrost_gem_shrinker_cleanup(struct drm_device *dev);
> >
> >  void panfrost_gem_set_label(struct drm_gem_object *obj, const char *label);
> >
> > +#ifdef CONFIG_DEBUG_FS
> > +void panfrost_gem_debugfs_print_bos(struct panfrost_device *pfdev,
> > +				    struct seq_file *m);
> > +static inline void
> > +panfrost_gem_debugfs_init_bo(struct panfrost_gem_object *bo)
> > +{
> > +	bo->debugfs.initialised = true;
> > +}
> > +#else
> > +static inline void
> > +panfrost_gem_debugfs_init_bo(struct panfrost_gem_object *bo) {};
> > +#endif
> > +
> >  #endif /* __PANFROST_GEM_H__ */


Adrian Larumbe

Re: [PATCH 1/3] drm/panfrost: Add BO labelling to Panfrost

[Adrián Larumbe]

On 07.05.2025 14:18, Steven Price wrote:
> On 24/04/2025 03:21, Adrián Larumbe wrote:
> > Unlike in Panthor, from where this change is based on, there is no need
> > to support tagging of BO's other than UM-exposed ones, so all strings
> > can be freed with kfree().
> >
> > This commit is done in preparation of a following one that will allow
> > UM to set BO labels through a new ioctl().
> >
> > Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com>
>
> Reviewed-by: Steven Price <steven.price@arm.com>
>
> But one comment below
>
> > ---
> >  drivers/gpu/drm/panfrost/panfrost_gem.c | 19 +++++++++++++++++++
> >  drivers/gpu/drm/panfrost/panfrost_gem.h | 16 ++++++++++++++++
> >  2 files changed, 35 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.c b/drivers/gpu/drm/panfrost/panfrost_gem.c
> > index 963f04ba2de6..a7a29974d8b1 100644
> > --- a/drivers/gpu/drm/panfrost/panfrost_gem.c
> > +++ b/drivers/gpu/drm/panfrost/panfrost_gem.c
> > @@ -1,6 +1,7 @@
> >  // SPDX-License-Identifier: GPL-2.0
> >  /* Copyright 2019 Linaro, Ltd, Rob Herring <robh@kernel.org> */
> >
> > +#include <linux/cleanup.h>
> >  #include <linux/err.h>
> >  #include <linux/slab.h>
> >  #include <linux/dma-buf.h>
> > @@ -35,6 +36,9 @@ static void panfrost_gem_free_object(struct drm_gem_object *obj)
> >  	 */
> >  	WARN_ON_ONCE(!list_empty(&bo->mappings.list));
> >
> > +	kfree(bo->label.str);
> > +	mutex_destroy(&bo->label.lock);
> > +
> >  	if (bo->sgts) {
> >  		int i;
> >  		int n_sgt = bo->base.base.size / SZ_2M;
> > @@ -260,6 +264,7 @@ struct drm_gem_object *panfrost_gem_create_object(struct drm_device *dev, size_t
> >  	mutex_init(&obj->mappings.lock);
> >  	obj->base.base.funcs = &panfrost_gem_funcs;
> >  	obj->base.map_wc = !pfdev->coherent;
> > +	mutex_init(&obj->label.lock);
> >
> >  	return &obj->base.base;
> >  }
> > @@ -302,3 +307,17 @@ panfrost_gem_prime_import_sg_table(struct drm_device *dev,
> >
> >  	return obj;
> >  }
> > +
> > +void
> > +panfrost_gem_set_label(struct drm_gem_object *obj, const char *label)
> > +{
> > +	struct panfrost_gem_object *bo = to_panfrost_bo(obj);
> > +	const char *old_label;
> > +
> > +	scoped_guard(mutex, &bo->label.lock) {
> > +		old_label = bo->label.str;
> > +		bo->label.str = label;
> > +	}
> > +
> > +	kfree(old_label);
> > +}
> > diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.h b/drivers/gpu/drm/panfrost/panfrost_gem.h
> > index 7516b7ecf7fe..c0be2934f229 100644
> > --- a/drivers/gpu/drm/panfrost/panfrost_gem.h
> > +++ b/drivers/gpu/drm/panfrost/panfrost_gem.h
> > @@ -41,6 +41,20 @@ struct panfrost_gem_object {
> >  	 */
> >  	size_t heap_rss_size;
> >
> > +	/**
> > +	 * @label: BO tagging fields. The label can be assigned within the
> > +	 * driver itself or through a specific IOCTL.
>
> From the commit message (about the use of kfree()) I assume we are not
> expecting this to be assigned "within the driver itself"?
>
That's right, that was only the case in Panthor when labelling kernel BOs.
Since all GEM BO's in Panfrost are user-facing, there's no need to label
any within the driver itself.
>
> Thanks,
> Steve
>
> > +	 */
> > +	struct {
> > +		/**
> > +		 * @label.str: Pointer to NULL-terminated string,
> > +		 */
> > +		const char *str;
> > +
> > +		/** @lock.str: Protects access to the @label.str field. */
> > +		struct mutex lock;
> > +	} label;
> > +
> >  	bool noexec		:1;
> >  	bool is_heap		:1;
> >  };
> > @@ -89,4 +103,6 @@ void panfrost_gem_teardown_mappings_locked(struct panfrost_gem_object *bo);
> >  int panfrost_gem_shrinker_init(struct drm_device *dev);
> >  void panfrost_gem_shrinker_cleanup(struct drm_device *dev);
> >
> > +void panfrost_gem_set_label(struct drm_gem_object *obj, const char *label);
> > +
> >  #endif /* __PANFROST_GEM_H__ */

Adrian Larumbe

Re: [PATCH 1/3] drm/panfrost: Add BO labelling to Panfrost

[Boris Brezillon]

On Wed, 7 May 2025 14:01:04 +0100
Adrián Larumbe <adrian.larumbe@collabora.com> wrote:

> On 06.05.2025 08:54, Boris Brezillon wrote:
> > On Thu, 24 Apr 2025 03:21:30 +0100
> > Adrián Larumbe <adrian.larumbe@collabora.com> wrote:
> >  
> > > Unlike in Panthor, from where this change is based on, there is no need
> > > to support tagging of BO's other than UM-exposed ones, so all strings
> > > can be freed with kfree().
> > >
> > > This commit is done in preparation of a following one that will allow
> > > UM to set BO labels through a new ioctl().
> > >
> > > Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com>
> > > ---
> > >  drivers/gpu/drm/panfrost/panfrost_gem.c | 19 +++++++++++++++++++
> > >  drivers/gpu/drm/panfrost/panfrost_gem.h | 16 ++++++++++++++++
> > >  2 files changed, 35 insertions(+)
> > >
> > > diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.c b/drivers/gpu/drm/panfrost/panfrost_gem.c
> > > index 963f04ba2de6..a7a29974d8b1 100644
> > > --- a/drivers/gpu/drm/panfrost/panfrost_gem.c
> > > +++ b/drivers/gpu/drm/panfrost/panfrost_gem.c
> > > @@ -1,6 +1,7 @@
> > >  // SPDX-License-Identifier: GPL-2.0
> > >  /* Copyright 2019 Linaro, Ltd, Rob Herring <robh@kernel.org> */
> > >
> > > +#include <linux/cleanup.h>
> > >  #include <linux/err.h>
> > >  #include <linux/slab.h>
> > >  #include <linux/dma-buf.h>
> > > @@ -35,6 +36,9 @@ static void panfrost_gem_free_object(struct drm_gem_object *obj)
> > >  	 */
> > >  	WARN_ON_ONCE(!list_empty(&bo->mappings.list));
> > >
> > > +	kfree(bo->label.str);
> > > +	mutex_destroy(&bo->label.lock);
> > > +
> > >  	if (bo->sgts) {
> > >  		int i;
> > >  		int n_sgt = bo->base.base.size / SZ_2M;
> > > @@ -260,6 +264,7 @@ struct drm_gem_object *panfrost_gem_create_object(struct drm_device *dev, size_t
> > >  	mutex_init(&obj->mappings.lock);
> > >  	obj->base.base.funcs = &panfrost_gem_funcs;
> > >  	obj->base.map_wc = !pfdev->coherent;
> > > +	mutex_init(&obj->label.lock);
> > >
> > >  	return &obj->base.base;
> > >  }
> > > @@ -302,3 +307,17 @@ panfrost_gem_prime_import_sg_table(struct drm_device *dev,
> > >
> > >  	return obj;
> > >  }
> > > +
> > > +void
> > > +panfrost_gem_set_label(struct drm_gem_object *obj, const char *label)
> > > +{
> > > +	struct panfrost_gem_object *bo = to_panfrost_bo(obj);
> > > +	const char *old_label;
> > > +
> > > +	scoped_guard(mutex, &bo->label.lock) {
> > > +		old_label = bo->label.str;
> > > +		bo->label.str = label;
> > > +	}
> > > +
> > > +	kfree(old_label);
> > > +}
> > > diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.h b/drivers/gpu/drm/panfrost/panfrost_gem.h
> > > index 7516b7ecf7fe..c0be2934f229 100644
> > > --- a/drivers/gpu/drm/panfrost/panfrost_gem.h
> > > +++ b/drivers/gpu/drm/panfrost/panfrost_gem.h
> > > @@ -41,6 +41,20 @@ struct panfrost_gem_object {
> > >  	 */
> > >  	size_t heap_rss_size;
> > >
> > > +	/**
> > > +	 * @label: BO tagging fields. The label can be assigned within the
> > > +	 * driver itself or through a specific IOCTL.
> > > +	 */
> > > +	struct {
> > > +		/**
> > > +		 * @label.str: Pointer to NULL-terminated string,
> > > +		 */
> > > +		const char *str;
> > > +
> > > +		/** @lock.str: Protects access to the @label.str field. */
> > > +		struct mutex lock;
> > > +	} label;  
> >
> > Can we do as we did in panthor, and put those fields in the debugfs
> > field.  
> 
> BO labelling fields must be present outside of DebugFS builds.

Hm, right. I see those are not in an #ifdef CONFIG_DEBUGFS section in
panthor. I don't really see a good reason to store labels if we don't
have a way to retrieve/display them, but I guess that'd make sense if
we introduce a GET_LABEL ioctl.

> 
> > +
> >  	bool noexec		:1;
> >  	bool is_heap		:1;
> >  };
> > @@ -89,4 +103,6 @@ void panfrost_gem_teardown_mappings_locked(struct panfrost_gem_object *bo);
> >  int panfrost_gem_shrinker_init(struct drm_device *dev);
> >  void panfrost_gem_shrinker_cleanup(struct drm_device *dev);
> >
> > +void panfrost_gem_set_label(struct drm_gem_object *obj, const char *label);
> > +
> >  #endif /* __PANFROST_GEM_H__ */  
> 
> 
> Adrian Larumbe