On Wed, Apr 09, 2025 at 10:22:22PM +0100, Adrián Larumbe wrote:
> 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.laru...@collabora.com>
Reviewed-by: Liviu Dudau <liviu.du...@arm.com>
Best regards,
Liviu
> ---
> 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 | 186 +++++++++++++++++++++++
> drivers/gpu/drm/panthor/panthor_gem.h | 59 +++++++
> 5 files changed, 287 insertions(+)
>
> 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..ca9baa7b43da 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_bo_set_mask(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_bo_set_mask(bo, 0);
> +
> return ret;
> }
>
> @@ -288,3 +338,139 @@ 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("unknown-bit%d", bit);
> + else
> + 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[24] = {};
> + char gem_usage_str[24] = {};
> + 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, "%-24s%-24s", 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..8c56e0c0dc9c 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_bo_set_mask(struct panthor_gem_object *bo, u32 type_mask)
> +{
> + bo->debugfs.flags = type_mask |
> PANTHOR_DEBUGFS_GEM_USAGE_FLAG_INITIALIZED;
> +}
> +
> +#else
> +void panthor_gem_debugfs_bo_set_mask(struct panthor_gem_object *bo, u32
> type_mask) {};
> +#endif
> +
> #endif /* __PANTHOR_GEM_H__ */
> --
> 2.48.1
>
--
====================
| I would like to |
| fix the world, |
| but they're not |
| giving me the |
\ source code! /
---------------
¯\_(ツ)_/¯
