diff mbox series

[v7,4/4] drm/panthor: show device-wide list of DRM GEM objects over DebugFS

Message ID 20250411150357.3308921-5-adrian.larumbe@collabora.com
State New
Headers show
Series Panthor BO tagging and GEMS debug display | expand

Commit Message

Adrián Larumbe April 11, 2025, 3:03 p.m. UTC
Add a device DebugFS file that displays a complete list of all the DRM
GEM objects that are exposed to UM through a DRM handle.

Since leaking object identifiers that might belong to a different NS is
inadmissible, this functionality is only made available in debug builds
with DEBUGFS support enabled.

File format is that of a table, with each entry displaying a variety of
fields with information about each GEM object.

Each GEM object entry in the file displays the following information
fields: Client PID, BO's global name, reference count, BO virtual size,
BO resize size, VM address in its DRM-managed range, BO label and a GEM
state flags.

There's also a usage flags field for the type of BO, which tells us
whether it's a kernel BO and/or mapped onto the FW's address space.

Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com>
Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
---
 drivers/gpu/drm/panthor/panthor_device.c |   5 +
 drivers/gpu/drm/panthor/panthor_device.h |  11 ++
 drivers/gpu/drm/panthor/panthor_drv.c    |  26 ++++
 drivers/gpu/drm/panthor/panthor_gem.c    | 182 +++++++++++++++++++++++
 drivers/gpu/drm/panthor/panthor_gem.h    |  59 ++++++++
 5 files changed, 283 insertions(+)
diff mbox series

Patch

diff --git a/drivers/gpu/drm/panthor/panthor_device.c b/drivers/gpu/drm/panthor/panthor_device.c
index a9da1d1eeb70..b776e1a2e4f3 100644
--- a/drivers/gpu/drm/panthor/panthor_device.c
+++ b/drivers/gpu/drm/panthor/panthor_device.c
@@ -184,6 +184,11 @@  int panthor_device_init(struct panthor_device *ptdev)
 	if (ret)
 		return ret;
 
+#ifdef CONFIG_DEBUG_FS
+	drmm_mutex_init(&ptdev->base, &ptdev->gems.lock);
+	INIT_LIST_HEAD(&ptdev->gems.node);
+#endif
+
 	atomic_set(&ptdev->pm.state, PANTHOR_DEVICE_PM_STATE_SUSPENDED);
 	p = alloc_page(GFP_KERNEL | __GFP_ZERO);
 	if (!p)
diff --git a/drivers/gpu/drm/panthor/panthor_device.h b/drivers/gpu/drm/panthor/panthor_device.h
index da6574021664..86206a961b38 100644
--- a/drivers/gpu/drm/panthor/panthor_device.h
+++ b/drivers/gpu/drm/panthor/panthor_device.h
@@ -205,6 +205,17 @@  struct panthor_device {
 
 	/** @fast_rate: Maximum device clock frequency. Set by DVFS */
 	unsigned long fast_rate;
+
+#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 panthor_gpu_usage {
diff --git a/drivers/gpu/drm/panthor/panthor_drv.c b/drivers/gpu/drm/panthor/panthor_drv.c
index 983b24f1236c..4d3f2eb29a47 100644
--- a/drivers/gpu/drm/panthor/panthor_drv.c
+++ b/drivers/gpu/drm/panthor/panthor_drv.c
@@ -1535,9 +1535,35 @@  static const struct file_operations panthor_drm_driver_fops = {
 };
 
 #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 panthor_device *ptdev = container_of(dev, struct panthor_device, base);
+
+	panthor_gem_debugfs_print_bos(ptdev, 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 panthor_debugfs_init(struct drm_minor *minor)
 {
 	panthor_mmu_debugfs_init(minor);
+	panthor_gems_debugfs_init(minor);
 }
 #endif
 
diff --git a/drivers/gpu/drm/panthor/panthor_gem.c b/drivers/gpu/drm/panthor/panthor_gem.c
index 3c5fc854356e..fab7a11ab71f 100644
--- a/drivers/gpu/drm/panthor/panthor_gem.c
+++ b/drivers/gpu/drm/panthor/panthor_gem.c
@@ -11,14 +11,51 @@ 
 #include <drm/panthor_drm.h>
 
 #include "panthor_device.h"
+#include "panthor_fw.h"
 #include "panthor_gem.h"
 #include "panthor_mmu.h"
 
+#ifdef CONFIG_DEBUG_FS
+static void panthor_gem_debugfs_bo_add(struct panthor_device *ptdev,
+				       struct panthor_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 panthor_gem_debugfs_bo_rm(struct panthor_gem_object *bo)
+{
+	struct panthor_device *ptdev = container_of(bo->base.base.dev,
+						    struct panthor_device, base);
+
+	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 panthor_gem_debugfs_bo_add(struct panthor_device *ptdev,
+				       struct panthor_gem_object *bo)
+{}
+static void panthor_gem_debugfs_bo_rm(struct panthor_gem_object *bo) {}
+#endif
+
 static void panthor_gem_free_object(struct drm_gem_object *obj)
 {
 	struct panthor_gem_object *bo = to_panthor_bo(obj);
 	struct drm_gem_object *vm_root_gem = bo->exclusive_vm_root_gem;
 
+	panthor_gem_debugfs_bo_rm(bo);
+
 	/*
 	 * Label might have been allocated with kstrdup_const(),
 	 * we need to take that into account when freeing the memory
@@ -87,6 +124,7 @@  panthor_kernel_bo_create(struct panthor_device *ptdev, struct panthor_vm *vm,
 	struct drm_gem_shmem_object *obj;
 	struct panthor_kernel_bo *kbo;
 	struct panthor_gem_object *bo;
+	u32 debug_flags = PANTHOR_DEBUGFS_GEM_USAGE_FLAG_KERNEL;
 	int ret;
 
 	if (drm_WARN_ON(&ptdev->base, !vm))
@@ -106,7 +144,11 @@  panthor_kernel_bo_create(struct panthor_device *ptdev, struct panthor_vm *vm,
 	kbo->obj = &obj->base;
 	bo->flags = bo_flags;
 
+	if (vm == panthor_fw_vm(ptdev))
+		debug_flags |= PANTHOR_DEBUGFS_GEM_USAGE_FLAG_FW_MAPPED;
+
 	panthor_gem_kernel_bo_set_label(kbo, name);
+	panthor_gem_debugfs_set_usage_flags(to_panthor_bo(kbo->obj), debug_flags);
 
 	/* The system and GPU MMU page size might differ, which becomes a
 	 * problem for FW sections that need to be mapped at explicit address
@@ -209,6 +251,8 @@  struct drm_gem_object *panthor_gem_create_object(struct drm_device *ddev, size_t
 	drm_gem_gpuva_set_lock(&obj->base.base, &obj->gpuva_list_lock);
 	mutex_init(&obj->label.lock);
 
+	panthor_gem_debugfs_bo_add(ptdev, obj);
+
 	return &obj->base.base;
 }
 
@@ -257,6 +301,12 @@  panthor_gem_create_with_handle(struct drm_file *file,
 	/* drop reference from allocate - handle holds it now. */
 	drm_gem_object_put(&shmem->base);
 
+	/*
+	 * No explicit flags are needed in the call below, since the
+	 * function internally sets the INITIALIZED bit for us.
+	 */
+	panthor_gem_debugfs_set_usage_flags(bo, 0);
+
 	return ret;
 }
 
@@ -288,3 +338,135 @@  panthor_gem_kernel_bo_set_label(struct panthor_kernel_bo *bo, const char *label)
 
 	panthor_gem_bo_set_label(bo->obj, str);
 }
+
+#ifdef CONFIG_DEBUG_FS
+static void
+panthor_gem_debugfs_format_flags(char flags_str[], int flags_len,
+				 const char * const names[], u32 name_count,
+				 u32 flags)
+{
+	bool first = true;
+	int offset = 0;
+
+#define ACC_FLAGS(...) \
+	({ \
+		offset += snprintf(flags_str + offset, flags_len - offset, ##__VA_ARGS__); \
+		if (offset == flags_len) \
+			return; \
+	})
+
+	ACC_FLAGS("%c", '(');
+
+	if (!flags)
+		ACC_FLAGS("%s", "none");
+
+	while (flags) {
+		u32 bit = fls(flags) - 1;
+		u32 idx = bit + 1;
+
+		if (!first)
+			ACC_FLAGS("%s", ",");
+
+		if (idx < name_count && names[idx])
+			ACC_FLAGS("%s", names[idx]);
+
+		first = false;
+		flags &= ~BIT(bit);
+	}
+
+	ACC_FLAGS("%c", ')');
+
+#undef ACC_FLAGS
+}
+
+struct gem_size_totals {
+	size_t size;
+	size_t resident;
+	size_t reclaimable;
+};
+
+static void panthor_gem_debugfs_bo_print(struct panthor_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;
+	char gem_state_str[64] = {};
+	char gem_usage_str[64] = {};
+	u32 gem_usage_flags = bo->debugfs.flags & (u32)~PANTHOR_DEBUGFS_GEM_USAGE_FLAG_INITIALIZED;
+	u32 gem_state_flags = 0;
+
+	static const char * const gem_state_flags_names[] = {
+		[PANTHOR_DEBUGFS_GEM_STATE_FLAG_IMPORTED] = "imported",
+		[PANTHOR_DEBUGFS_GEM_STATE_FLAG_EXPORTED] = "exported",
+	};
+
+	static const char * const gem_usage_flags_names[] = {
+		[PANTHOR_DEBUGFS_GEM_USAGE_FLAG_KERNEL] = "kernel",
+		[PANTHOR_DEBUGFS_GEM_USAGE_FLAG_FW_MAPPED] = "fw-mapped",
+	};
+
+	/* Skip BOs being destroyed. */
+	if (!refcount)
+		return;
+
+	resident_size = bo->base.pages != NULL ? 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%-16zd%-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 != NULL)
+		gem_state_flags |= PANTHOR_DEBUGFS_GEM_STATE_FLAG_IMPORTED;
+	if (bo->base.base.dma_buf != NULL)
+		gem_state_flags |= PANTHOR_DEBUGFS_GEM_STATE_FLAG_EXPORTED;
+
+	panthor_gem_debugfs_format_flags(gem_state_str, sizeof(gem_state_str),
+					 gem_state_flags_names, ARRAY_SIZE(gem_state_flags_names),
+					 gem_state_flags);
+	panthor_gem_debugfs_format_flags(gem_usage_str, sizeof(gem_usage_str),
+					 gem_usage_flags_names, ARRAY_SIZE(gem_usage_flags_names),
+					 gem_usage_flags);
+
+	seq_printf(m, "%-64s%-64s", gem_state_str, gem_usage_str);
+
+	scoped_guard(mutex, &bo->label.lock) {
+		seq_printf(m, "%s", bo->label.str ? : "");
+	}
+
+	seq_puts(m, "\n");
+
+	totals->size += bo->base.base.size;
+	totals->resident += resident_size;
+	if (bo->base.madv > 0)
+		totals->reclaimable += resident_size;
+}
+
+void panthor_gem_debugfs_print_bos(struct panthor_device *ptdev,
+				   struct seq_file *m)
+{
+	struct gem_size_totals totals = {0};
+	struct panthor_gem_object *bo;
+
+	seq_puts(m, "created-by                      global-name     refcount        size            resident-size   file-offset     state                                                           usage                                                           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.flags & PANTHOR_DEBUGFS_GEM_USAGE_FLAG_INITIALIZED)
+				panthor_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/panthor/panthor_gem.h b/drivers/gpu/drm/panthor/panthor_gem.h
index 62aea06dbc6d..03aec800cac5 100644
--- a/drivers/gpu/drm/panthor/panthor_gem.h
+++ b/drivers/gpu/drm/panthor/panthor_gem.h
@@ -15,6 +15,48 @@  struct panthor_vm;
 
 #define PANTHOR_BO_LABEL_MAXLEN	PAGE_SIZE
 
+enum panthor_debugfs_gem_state_flags {
+	/** @PANTHOR_DEBUGFS_GEM_STATE_FLAG_IMPORTED: GEM BO is PRIME imported. */
+	PANTHOR_DEBUGFS_GEM_STATE_FLAG_IMPORTED = BIT(0),
+
+	/** @PANTHOR_DEBUGFS_GEM_STATE_FLAG_EXPORTED: GEM BO is PRIME exported. */
+	PANTHOR_DEBUGFS_GEM_STATE_FLAG_EXPORTED = BIT(1),
+};
+
+enum panthor_debugfs_gem_usage_flags {
+	/** @PANTHOR_DEBUGFS_GEM_USAGE_FLAG_KERNEL: BO is for kernel use only. */
+	PANTHOR_DEBUGFS_GEM_USAGE_FLAG_KERNEL = BIT(0),
+
+	/** @PANTHOR_DEBUGFS_GEM_USAGE_FLAG_FW_MAPPED: BO is mapped on the FW VM. */
+	PANTHOR_DEBUGFS_GEM_USAGE_FLAG_FW_MAPPED = BIT(1),
+
+	/** @PANTHOR_DEBUGFS_GEM_USAGE_FLAG_INITIALIZED: BO is ready for DebugFS display. */
+	PANTHOR_DEBUGFS_GEM_USAGE_FLAG_INITIALIZED = BIT(31),
+};
+
+/**
+ * struct panthor_gem_debugfs - GEM object's DebugFS list information
+ */
+struct panthor_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;
+
+	/** @flags: Combination of panthor_debugfs_gem_usage_flags flags */
+	u32 flags;
+};
+
 /**
  * struct panthor_gem_object - Driver specific GEM object.
  */
@@ -62,6 +104,10 @@  struct panthor_gem_object {
 		/** @lock.str: Protects access to the @label.str field. */
 		struct mutex lock;
 	} label;
+
+#ifdef CONFIG_DEBUG_FS
+	struct panthor_gem_debugfs debugfs;
+#endif
 };
 
 /**
@@ -157,4 +203,17 @@  panthor_kernel_bo_create(struct panthor_device *ptdev, struct panthor_vm *vm,
 
 void panthor_kernel_bo_destroy(struct panthor_kernel_bo *bo);
 
+#ifdef CONFIG_DEBUG_FS
+void panthor_gem_debugfs_print_bos(struct panthor_device *pfdev,
+				   struct seq_file *m);
+static inline void
+panthor_gem_debugfs_set_usage_flags(struct panthor_gem_object *bo, u32 usage_flags)
+{
+	bo->debugfs.flags = usage_flags | PANTHOR_DEBUGFS_GEM_USAGE_FLAG_INITIALIZED;
+}
+
+#else
+void panthor_gem_debugfs_set_usage_flags(struct panthor_gem_object *bo, u32 usage_flags) {};
+#endif
+
 #endif /* __PANTHOR_GEM_H__ */