[PATCH v2 9/9] drm/vc4: Add an interface for capturing the GPU state after a hang.

From: Eric Anholt
Date: Tue Dec 08 2015 - 13:32:45 EST


This can be parsed with vc4-gpu-tools tools for trying to figure out
what was going on.

Signed-off-by: Eric Anholt <eric@xxxxxxxxxx>
---

v2: Use __u32-style types.

drivers/gpu/drm/vc4/vc4_drv.c | 2 +
drivers/gpu/drm/vc4/vc4_drv.h | 4 +
drivers/gpu/drm/vc4/vc4_gem.c | 185 ++++++++++++++++++++++++++++++++++++++++++
include/uapi/drm/vc4_drm.h | 45 ++++++++++
4 files changed, 236 insertions(+)

diff --git a/drivers/gpu/drm/vc4/vc4_drv.c b/drivers/gpu/drm/vc4/vc4_drv.c
index 2cfee59..97226b6 100644
--- a/drivers/gpu/drm/vc4/vc4_drv.c
+++ b/drivers/gpu/drm/vc4/vc4_drv.c
@@ -80,6 +80,8 @@ static const struct drm_ioctl_desc vc4_drm_ioctls[] = {
DRM_IOCTL_DEF_DRV(VC4_CREATE_BO, vc4_create_bo_ioctl, 0),
DRM_IOCTL_DEF_DRV(VC4_MMAP_BO, vc4_mmap_bo_ioctl, 0),
DRM_IOCTL_DEF_DRV(VC4_CREATE_SHADER_BO, vc4_create_shader_bo_ioctl, 0),
+ DRM_IOCTL_DEF_DRV(VC4_GET_HANG_STATE, vc4_get_hang_state_ioctl,
+ DRM_ROOT_ONLY),
};

static struct drm_driver vc4_drm_driver = {
diff --git a/drivers/gpu/drm/vc4/vc4_drv.h b/drivers/gpu/drm/vc4/vc4_drv.h
index f9927d8..080865e 100644
--- a/drivers/gpu/drm/vc4/vc4_drv.h
+++ b/drivers/gpu/drm/vc4/vc4_drv.h
@@ -19,6 +19,8 @@ struct vc4_dev {

struct drm_fbdev_cma *fbdev;

+ struct vc4_hang_state *hang_state;
+
/* The kernel-space BO cache. Tracks buffers that have been
* unreferenced by all other users (refcounts of 0!) but not
* yet freed, so we can do cheap allocations.
@@ -361,6 +363,8 @@ int vc4_create_shader_bo_ioctl(struct drm_device *dev, void *data,
struct drm_file *file_priv);
int vc4_mmap_bo_ioctl(struct drm_device *dev, void *data,
struct drm_file *file_priv);
+int vc4_get_hang_state_ioctl(struct drm_device *dev, void *data,
+ struct drm_file *file_priv);
int vc4_mmap(struct file *filp, struct vm_area_struct *vma);
int vc4_prime_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma);
void *vc4_prime_vmap(struct drm_gem_object *obj);
diff --git a/drivers/gpu/drm/vc4/vc4_gem.c b/drivers/gpu/drm/vc4/vc4_gem.c
index 5fb0556..39f29e7 100644
--- a/drivers/gpu/drm/vc4/vc4_gem.c
+++ b/drivers/gpu/drm/vc4/vc4_gem.c
@@ -40,6 +40,186 @@ vc4_queue_hangcheck(struct drm_device *dev)
round_jiffies_up(jiffies + msecs_to_jiffies(100)));
}

+struct vc4_hang_state {
+ struct drm_vc4_get_hang_state user_state;
+
+ u32 bo_count;
+ struct drm_gem_object **bo;
+};
+
+static void
+vc4_free_hang_state(struct drm_device *dev, struct vc4_hang_state *state)
+{
+ unsigned int i;
+
+ mutex_lock(&dev->struct_mutex);
+ for (i = 0; i < state->user_state.bo_count; i++)
+ drm_gem_object_unreference(state->bo[i]);
+ mutex_unlock(&dev->struct_mutex);
+
+ kfree(state);
+}
+
+int
+vc4_get_hang_state_ioctl(struct drm_device *dev, void *data,
+ struct drm_file *file_priv)
+{
+ struct drm_vc4_get_hang_state *get_state = data;
+ struct drm_vc4_get_hang_state_bo *bo_state;
+ struct vc4_hang_state *kernel_state;
+ struct drm_vc4_get_hang_state *state;
+ struct vc4_dev *vc4 = to_vc4_dev(dev);
+ unsigned long irqflags;
+ u32 i;
+ int ret;
+
+ spin_lock_irqsave(&vc4->job_lock, irqflags);
+ kernel_state = vc4->hang_state;
+ if (!kernel_state) {
+ spin_unlock_irqrestore(&vc4->job_lock, irqflags);
+ return -ENOENT;
+ }
+ state = &kernel_state->user_state;
+
+ /* If the user's array isn't big enough, just return the
+ * required array size.
+ */
+ if (get_state->bo_count < state->bo_count) {
+ get_state->bo_count = state->bo_count;
+ spin_unlock_irqrestore(&vc4->job_lock, irqflags);
+ return 0;
+ }
+
+ vc4->hang_state = NULL;
+ spin_unlock_irqrestore(&vc4->job_lock, irqflags);
+
+ /* Save the user's BO pointer, so we don't stomp it with the memcpy. */
+ state->bo = get_state->bo;
+ memcpy(get_state, state, sizeof(*state));
+
+ bo_state = kcalloc(state->bo_count, sizeof(*bo_state), GFP_KERNEL);
+ if (!bo_state) {
+ ret = -ENOMEM;
+ goto err_free;
+ }
+
+ for (i = 0; i < state->bo_count; i++) {
+ struct vc4_bo *vc4_bo = to_vc4_bo(kernel_state->bo[i]);
+ u32 handle;
+
+ ret = drm_gem_handle_create(file_priv, kernel_state->bo[i],
+ &handle);
+
+ if (ret) {
+ state->bo_count = i - 1;
+ goto err;
+ }
+ bo_state[i].handle = handle;
+ bo_state[i].paddr = vc4_bo->base.paddr;
+ bo_state[i].size = vc4_bo->base.base.size;
+ }
+
+ ret = copy_to_user((void __user *)(uintptr_t)get_state->bo,
+ bo_state,
+ state->bo_count * sizeof(*bo_state));
+ kfree(bo_state);
+
+err_free:
+
+ vc4_free_hang_state(dev, kernel_state);
+
+err:
+ return ret;
+}
+
+static void
+vc4_save_hang_state(struct drm_device *dev)
+{
+ struct vc4_dev *vc4 = to_vc4_dev(dev);
+ struct drm_vc4_get_hang_state *state;
+ struct vc4_hang_state *kernel_state;
+ struct vc4_exec_info *exec;
+ struct vc4_bo *bo;
+ unsigned long irqflags;
+ unsigned int i, unref_list_count;
+
+ kernel_state = kcalloc(1, sizeof(*state), GFP_KERNEL);
+ if (!kernel_state)
+ return;
+
+ state = &kernel_state->user_state;
+
+ spin_lock_irqsave(&vc4->job_lock, irqflags);
+ exec = vc4_first_job(vc4);
+ if (!exec) {
+ spin_unlock_irqrestore(&vc4->job_lock, irqflags);
+ return;
+ }
+
+ unref_list_count = 0;
+ list_for_each_entry(bo, &exec->unref_list, unref_head)
+ unref_list_count++;
+
+ state->bo_count = exec->bo_count + unref_list_count;
+ kernel_state->bo = kcalloc(state->bo_count, sizeof(*kernel_state->bo),
+ GFP_ATOMIC);
+ if (!kernel_state->bo) {
+ spin_unlock_irqrestore(&vc4->job_lock, irqflags);
+ return;
+ }
+
+ for (i = 0; i < exec->bo_count; i++) {
+ drm_gem_object_reference(&exec->bo[i]->base);
+ kernel_state->bo[i] = &exec->bo[i]->base;
+ }
+
+ list_for_each_entry(bo, &exec->unref_list, unref_head) {
+ drm_gem_object_reference(&bo->base.base);
+ kernel_state->bo[i] = &bo->base.base;
+ i++;
+ }
+
+ state->start_bin = exec->ct0ca;
+ state->start_render = exec->ct1ca;
+
+ spin_unlock_irqrestore(&vc4->job_lock, irqflags);
+
+ state->ct0ca = V3D_READ(V3D_CTNCA(0));
+ state->ct0ea = V3D_READ(V3D_CTNEA(0));
+
+ state->ct1ca = V3D_READ(V3D_CTNCA(1));
+ state->ct1ea = V3D_READ(V3D_CTNEA(1));
+
+ state->ct0cs = V3D_READ(V3D_CTNCS(0));
+ state->ct1cs = V3D_READ(V3D_CTNCS(1));
+
+ state->ct0ra0 = V3D_READ(V3D_CT00RA0);
+ state->ct1ra0 = V3D_READ(V3D_CT01RA0);
+
+ state->bpca = V3D_READ(V3D_BPCA);
+ state->bpcs = V3D_READ(V3D_BPCS);
+ state->bpoa = V3D_READ(V3D_BPOA);
+ state->bpos = V3D_READ(V3D_BPOS);
+
+ state->vpmbase = V3D_READ(V3D_VPMBASE);
+
+ state->dbge = V3D_READ(V3D_DBGE);
+ state->fdbgo = V3D_READ(V3D_FDBGO);
+ state->fdbgb = V3D_READ(V3D_FDBGB);
+ state->fdbgr = V3D_READ(V3D_FDBGR);
+ state->fdbgs = V3D_READ(V3D_FDBGS);
+ state->errstat = V3D_READ(V3D_ERRSTAT);
+
+ spin_lock_irqsave(&vc4->job_lock, irqflags);
+ if (vc4->hang_state) {
+ spin_unlock_irqrestore(&vc4->job_lock, irqflags);
+ vc4_free_hang_state(dev, kernel_state);
+ } else {
+ vc4->hang_state = kernel_state;
+ spin_unlock_irqrestore(&vc4->job_lock, irqflags);
+ }
+}
+
static void
vc4_reset(struct drm_device *dev)
{
@@ -64,6 +244,8 @@ vc4_reset_work(struct work_struct *work)
struct vc4_dev *vc4 =
container_of(work, struct vc4_dev, hangcheck.reset_work);

+ vc4_save_hang_state(vc4->dev);
+
vc4_reset(vc4->dev);
}

@@ -679,4 +861,7 @@ vc4_gem_destroy(struct drm_device *dev)
}

vc4_bo_cache_destroy(dev);
+
+ if (vc4->hang_state)
+ vc4_free_hang_state(dev, vc4->hang_state);
}
diff --git a/include/uapi/drm/vc4_drm.h b/include/uapi/drm/vc4_drm.h
index fe4161b..eeb37e3 100644
--- a/include/uapi/drm/vc4_drm.h
+++ b/include/uapi/drm/vc4_drm.h
@@ -32,6 +32,7 @@
#define DRM_VC4_CREATE_BO 0x03
#define DRM_VC4_MMAP_BO 0x04
#define DRM_VC4_CREATE_SHADER_BO 0x05
+#define DRM_VC4_GET_HANG_STATE 0x06

#define DRM_IOCTL_VC4_SUBMIT_CL DRM_IOWR(DRM_COMMAND_BASE + DRM_VC4_SUBMIT_CL, struct drm_vc4_submit_cl)
#define DRM_IOCTL_VC4_WAIT_SEQNO DRM_IOWR(DRM_COMMAND_BASE + DRM_VC4_WAIT_SEQNO, struct drm_vc4_wait_seqno)
@@ -39,6 +40,7 @@
#define DRM_IOCTL_VC4_CREATE_BO DRM_IOWR(DRM_COMMAND_BASE + DRM_VC4_CREATE_BO, struct drm_vc4_create_bo)
#define DRM_IOCTL_VC4_MMAP_BO DRM_IOWR(DRM_COMMAND_BASE + DRM_VC4_MMAP_BO, struct drm_vc4_mmap_bo)
#define DRM_IOCTL_VC4_CREATE_SHADER_BO DRM_IOWR(DRM_COMMAND_BASE + DRM_VC4_CREATE_SHADER_BO, struct drm_vc4_create_shader_bo)
+#define DRM_IOCTL_VC4_GET_HANG_STATE DRM_IOWR(DRM_COMMAND_BASE + DRM_VC4_GET_HANG_STATE, struct drm_vc4_get_hang_state)

struct drm_vc4_submit_rcl_surface {
__u32 hindex; /* Handle index, or ~0 if not present. */
@@ -231,4 +233,47 @@ struct drm_vc4_create_shader_bo {
__u32 pad;
};

+struct drm_vc4_get_hang_state_bo {
+ __u32 handle;
+ __u32 paddr;
+ __u32 size;
+ __u32 pad;
+};
+
+/**
+ * struct drm_vc4_hang_state - ioctl argument for collecting state
+ * from a GPU hang for analysis.
+*/
+struct drm_vc4_get_hang_state {
+ /** Pointer to array of struct drm_vc4_get_hang_state_bo. */
+ __u64 bo;
+ /**
+ * On input, the size of the bo array. Output is the number
+ * of bos to be returned.
+ */
+ __u32 bo_count;
+
+ __u32 start_bin, start_render;
+
+ __u32 ct0ca, ct0ea;
+ __u32 ct1ca, ct1ea;
+ __u32 ct0cs, ct1cs;
+ __u32 ct0ra0, ct1ra0;
+
+ __u32 bpca, bpcs;
+ __u32 bpoa, bpos;
+
+ __u32 vpmbase;
+
+ __u32 dbge;
+ __u32 fdbgo;
+ __u32 fdbgb;
+ __u32 fdbgr;
+ __u32 fdbgs;
+ __u32 errstat;
+
+ /* Pad that we may save more registers into in the future. */
+ __u32 pad[16];
+};
+
#endif /* _UAPI_VC4_DRM_H_ */
--
2.6.2

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