i915_trace_points.o \
i915_ttm_buddy_manager.o \
i915_vma.o \
+ i915_vma_snapshot.o \
intel_wopcm.o
# general-purpose microcontroller (GuC) support
#include "i915_gem_ioctls.h"
#include "i915_trace.h"
#include "i915_user_extensions.h"
+#include "i915_vma_snapshot.h"
struct eb_vma {
struct i915_vma *vma;
struct eb_fence *fences;
unsigned long num_fences;
+#if IS_ENABLED(CONFIG_DRM_I915_CAPTURE_ERROR)
+ struct i915_capture_list *capture_lists[MAX_ENGINE_INSTANCE + 1];
+#endif
};
static int eb_parse(struct i915_execbuffer *eb);
static int eb_pin_engine(struct i915_execbuffer *eb, bool throttle);
static void eb_unpin_engine(struct i915_execbuffer *eb);
+static void eb_capture_release(struct i915_execbuffer *eb);
static inline bool eb_use_cmdparser(const struct i915_execbuffer *eb)
{
i915_vma_put(vma);
}
+ eb_capture_release(eb);
eb_unpin_engine(eb);
}
return NULL;
}
-static int eb_move_to_gpu(struct i915_execbuffer *eb)
+#if IS_ENABLED(CONFIG_DRM_I915_CAPTURE_ERROR)
+
+/* Stage with GFP_KERNEL allocations before we enter the signaling critical path */
+static void eb_capture_stage(struct i915_execbuffer *eb)
{
const unsigned int count = eb->buffer_count;
- unsigned int i = count;
- int err = 0, j;
+ unsigned int i = count, j;
+ struct i915_vma_snapshot *vsnap;
while (i--) {
struct eb_vma *ev = &eb->vma[i];
struct i915_vma *vma = ev->vma;
unsigned int flags = ev->flags;
- struct drm_i915_gem_object *obj = vma->obj;
- assert_vma_held(vma);
+ if (!(flags & EXEC_OBJECT_CAPTURE))
+ continue;
- if (flags & EXEC_OBJECT_CAPTURE) {
+ vsnap = i915_vma_snapshot_alloc(GFP_KERNEL);
+ if (!vsnap)
+ continue;
+
+ i915_vma_snapshot_init(vsnap, vma, "user");
+ for_each_batch_create_order(eb, j) {
struct i915_capture_list *capture;
- for_each_batch_create_order(eb, j) {
- if (!eb->requests[j])
- break;
+ capture = kmalloc(sizeof(*capture), GFP_KERNEL);
+ if (!capture)
+ continue;
- capture = kmalloc(sizeof(*capture), GFP_KERNEL);
- if (capture) {
- capture->next =
- eb->requests[j]->capture_list;
- capture->vma = vma;
- eb->requests[j]->capture_list = capture;
- }
- }
+ capture->next = eb->capture_lists[j];
+ capture->vma_snapshot = i915_vma_snapshot_get(vsnap);
+ eb->capture_lists[j] = capture;
+ }
+ i915_vma_snapshot_put(vsnap);
+ }
+}
+
+/* Commit once we're in the critical path */
+static void eb_capture_commit(struct i915_execbuffer *eb)
+{
+ unsigned int j;
+
+ for_each_batch_create_order(eb, j) {
+ struct i915_request *rq = eb->requests[j];
+
+ if (!rq)
+ break;
+
+ rq->capture_list = eb->capture_lists[j];
+ eb->capture_lists[j] = NULL;
+ }
+}
+
+/*
+ * Release anything that didn't get committed due to errors.
+ * The capture_list will otherwise be freed at request retire.
+ */
+static void eb_capture_release(struct i915_execbuffer *eb)
+{
+ unsigned int j;
+
+ for_each_batch_create_order(eb, j) {
+ if (eb->capture_lists[j]) {
+ i915_request_free_capture_list(eb->capture_lists[j]);
+ eb->capture_lists[j] = NULL;
}
+ }
+}
+
+static void eb_capture_list_clear(struct i915_execbuffer *eb)
+{
+ memset(eb->capture_lists, 0, sizeof(eb->capture_lists));
+}
+
+#else
+
+static void eb_capture_stage(struct i915_execbuffer *eb)
+{
+}
+
+static void eb_capture_commit(struct i915_execbuffer *eb)
+{
+}
+
+static void eb_capture_release(struct i915_execbuffer *eb)
+{
+}
+
+static void eb_capture_list_clear(struct i915_execbuffer *eb)
+{
+}
+
+#endif
+
+static int eb_move_to_gpu(struct i915_execbuffer *eb)
+{
+ const unsigned int count = eb->buffer_count;
+ unsigned int i = count;
+ int err = 0, j;
+
+ while (i--) {
+ struct eb_vma *ev = &eb->vma[i];
+ struct i915_vma *vma = ev->vma;
+ unsigned int flags = ev->flags;
+ struct drm_i915_gem_object *obj = vma->obj;
+
+ assert_vma_held(vma);
/*
* If the GPU is not _reading_ through the CPU cache, we need
/* Unconditionally flush any chipset caches (for streaming writes). */
intel_gt_chipset_flush(eb->gt);
+ eb_capture_commit(eb);
+
return 0;
err_skip:
}
/*
- * Whilst this request exists, batch_obj will be on the
- * active_list, and so will hold the active reference. Only when
- * this request is retired will the batch_obj be moved onto
- * the inactive_list and lose its active reference. Hence we do
- * not need to explicitly hold another reference here.
+ * Not really on stack, but we don't want to call
+ * kfree on the batch_snapshot when we put it, so use the
+ * _onstack interface.
*/
- eb->requests[i]->batch = eb->batches[i]->vma;
+ if (eb->batches[i]->vma)
+ i915_vma_snapshot_init_onstack(&eb->requests[i]->batch_snapshot,
+ eb->batches[i]->vma,
+ "batch");
if (eb->batch_pool) {
GEM_BUG_ON(intel_context_is_parallel(eb->context));
intel_gt_buffer_pool_mark_active(eb->batch_pool,
eb.fences = NULL;
eb.num_fences = 0;
+ eb_capture_list_clear(&eb);
+
memset(eb.requests, 0, sizeof(struct i915_request *) *
ARRAY_SIZE(eb.requests));
eb.composite_fence = NULL;
}
ww_acquire_done(&eb.ww.ctx);
+ eb_capture_stage(&eb);
out_fence = eb_requests_create(&eb, in_fence, out_fence_fd);
if (IS_ERR(out_fence)) {
static void print_request_ring(struct drm_printer *m, struct i915_request *rq)
{
+ struct i915_vma_snapshot *vsnap = &rq->batch_snapshot;
void *ring;
int size;
+ if (!i915_vma_snapshot_present(vsnap))
+ vsnap = NULL;
+
drm_printf(m,
"[head %04x, postfix %04x, tail %04x, batch 0x%08x_%08x]:\n",
rq->head, rq->postfix, rq->tail,
- rq->batch ? upper_32_bits(rq->batch->node.start) : ~0u,
- rq->batch ? lower_32_bits(rq->batch->node.start) : ~0u);
+ vsnap ? upper_32_bits(vsnap->gtt_offset) : ~0u,
+ vsnap ? lower_32_bits(vsnap->gtt_offset) : ~0u);
size = rq->tail - rq->head;
if (rq->tail < rq->head)
#include "i915_gpu_error.h"
#include "i915_memcpy.h"
#include "i915_scatterlist.h"
+#include "i915_vma_snapshot.h"
#define ALLOW_FAIL (__GFP_KSWAPD_RECLAIM | __GFP_RETRY_MAYFAIL | __GFP_NOWARN)
#define ATOMIC_MAYFAIL (GFP_ATOMIC | __GFP_NOWARN)
static struct i915_vma_coredump *
i915_vma_coredump_create(const struct intel_gt *gt,
- const struct i915_vma *vma,
- const char *name,
+ const struct i915_vma_snapshot *vsnap,
struct i915_vma_compress *compress)
{
struct i915_ggtt *ggtt = gt->ggtt;
might_sleep();
- if (!vma || !vma->pages || !compress)
+ if (!vsnap || !vsnap->pages || !compress)
return NULL;
dst = kmalloc(sizeof(*dst), ALLOW_FAIL);
}
INIT_LIST_HEAD(&dst->page_list);
- strcpy(dst->name, name);
+ strcpy(dst->name, vsnap->name);
dst->next = NULL;
- dst->gtt_offset = vma->node.start;
- dst->gtt_size = vma->node.size;
- dst->gtt_page_sizes = vma->page_sizes.gtt;
+ dst->gtt_offset = vsnap->gtt_offset;
+ dst->gtt_size = vsnap->gtt_size;
+ dst->gtt_page_sizes = vsnap->page_sizes;
dst->unused = 0;
ret = -EINVAL;
void __iomem *s;
dma_addr_t dma;
- for_each_sgt_daddr(dma, iter, vma->pages) {
+ for_each_sgt_daddr(dma, iter, vsnap->pages) {
mutex_lock(&ggtt->error_mutex);
ggtt->vm.insert_page(&ggtt->vm, dma, slot,
I915_CACHE_NONE, 0);
if (ret)
break;
}
- } else if (__i915_gem_object_is_lmem(vma->obj)) {
- struct intel_memory_region *mem = vma->obj->mm.region;
+ } else if (vsnap->mr && vsnap->mr->type != INTEL_MEMORY_SYSTEM) {
+ struct intel_memory_region *mem = vsnap->mr;
dma_addr_t dma;
- for_each_sgt_daddr(dma, iter, vma->pages) {
+ for_each_sgt_daddr(dma, iter, vsnap->pages) {
void __iomem *s;
s = io_mapping_map_wc(&mem->iomap,
} else {
struct page *page;
- for_each_sgt_page(page, iter, vma->pages) {
+ for_each_sgt_page(page, iter, vsnap->pages) {
void *s;
drm_clflush_pages(&page, 1);
struct intel_engine_capture_vma {
struct intel_engine_capture_vma *next;
- struct i915_vma *vma;
+ struct i915_vma_snapshot *vsnap;
char name[16];
+ bool lockdep_cookie;
};
static struct intel_engine_capture_vma *
-capture_vma(struct intel_engine_capture_vma *next,
- struct i915_vma *vma,
- const char *name,
- gfp_t gfp)
+capture_vma_snapshot(struct intel_engine_capture_vma *next,
+ struct i915_vma_snapshot *vsnap,
+ gfp_t gfp)
{
struct intel_engine_capture_vma *c;
- if (!vma)
+ if (!i915_vma_snapshot_present(vsnap))
return next;
c = kmalloc(sizeof(*c), gfp);
if (!c)
return next;
- if (!i915_active_acquire_if_busy(&vma->active)) {
+ if (!i915_vma_snapshot_resource_pin(vsnap, &c->lockdep_cookie)) {
kfree(c);
return next;
}
- strcpy(c->name, name);
- c->vma = vma; /* reference held while active */
+ strcpy(c->name, vsnap->name);
+ c->vsnap = vsnap;
+ i915_vma_snapshot_get(vsnap);
c->next = next;
return c;
}
+static struct intel_engine_capture_vma *
+capture_vma(struct intel_engine_capture_vma *next,
+ struct i915_vma *vma,
+ const char *name,
+ gfp_t gfp)
+{
+ struct i915_vma_snapshot *vsnap;
+
+ if (!vma)
+ return next;
+
+ /*
+ * If the vma isn't pinned, then the vma should be snapshotted
+ * to a struct i915_vma_snapshot at command submission time.
+ * Not here.
+ */
+ GEM_WARN_ON(!i915_vma_is_pinned(vma));
+ if (!i915_vma_is_pinned(vma))
+ return next;
+
+ vsnap = i915_vma_snapshot_alloc(gfp);
+ if (!vsnap)
+ return next;
+
+ i915_vma_snapshot_init(vsnap, vma, name);
+ next = capture_vma_snapshot(next, vsnap, gfp);
+
+ /* FIXME: Replace on async unbind. */
+ i915_vma_snapshot_put(vsnap);
+
+ return next;
+}
+
static struct intel_engine_capture_vma *
capture_user(struct intel_engine_capture_vma *capture,
const struct i915_request *rq,
struct i915_capture_list *c;
for (c = rq->capture_list; c; c = c->next)
- capture = capture_vma(capture, c->vma, "user", gfp);
+ capture = capture_vma_snapshot(capture, c->vma_snapshot, gfp);
return capture;
}
}
}
+static struct i915_vma_coredump *
+create_vma_coredump(const struct intel_gt *gt, struct i915_vma *vma,
+ const char *name, struct i915_vma_compress *compress)
+{
+ struct i915_vma_coredump *ret = NULL;
+ struct i915_vma_snapshot tmp;
+ bool lockdep_cookie;
+
+ if (!vma)
+ return NULL;
+
+ i915_vma_snapshot_init_onstack(&tmp, vma, name);
+ if (i915_vma_snapshot_resource_pin(&tmp, &lockdep_cookie)) {
+ ret = i915_vma_coredump_create(gt, &tmp, compress);
+ i915_vma_snapshot_resource_unpin(&tmp, lockdep_cookie);
+ }
+ i915_vma_snapshot_put_onstack(&tmp);
+
+ return ret;
+}
+
+static void add_vma_coredump(struct intel_engine_coredump *ee,
+ const struct intel_gt *gt,
+ struct i915_vma *vma,
+ const char *name,
+ struct i915_vma_compress *compress)
+{
+ add_vma(ee, create_vma_coredump(gt, vma, name, compress));
+}
+
struct intel_engine_coredump *
intel_engine_coredump_alloc(struct intel_engine_cs *engine, gfp_t gfp)
{
* as the simplest method to avoid being overwritten
* by userspace.
*/
- vma = capture_vma(vma, rq->batch, "batch", gfp);
+ vma = capture_vma_snapshot(vma, &rq->batch_snapshot, gfp);
vma = capture_user(vma, rq, gfp);
vma = capture_vma(vma, rq->ring->vma, "ring", gfp);
vma = capture_vma(vma, rq->context->state, "HW context", gfp);
while (capture) {
struct intel_engine_capture_vma *this = capture;
- struct i915_vma *vma = this->vma;
+ struct i915_vma_snapshot *vsnap = this->vsnap;
add_vma(ee,
i915_vma_coredump_create(engine->gt,
- vma, this->name,
- compress));
+ vsnap, compress));
- i915_active_release(&vma->active);
+ i915_vma_snapshot_resource_unpin(vsnap, this->lockdep_cookie);
+ i915_vma_snapshot_put(vsnap);
capture = this->next;
kfree(this);
}
- add_vma(ee,
- i915_vma_coredump_create(engine->gt,
- engine->status_page.vma,
- "HW Status",
- compress));
+ add_vma_coredump(ee, engine->gt, engine->status_page.vma,
+ "HW Status", compress);
- add_vma(ee,
- i915_vma_coredump_create(engine->gt,
- engine->wa_ctx.vma,
- "WA context",
- compress));
+ add_vma_coredump(ee, engine->gt, engine->wa_ctx.vma,
+ "WA context", compress);
}
static struct intel_engine_coredump *
}
}
if (rq)
- capture = intel_engine_coredump_add_request(ee, rq,
- ATOMIC_MAYFAIL);
+ rq = i915_request_get_rcu(rq);
+
+ if (!rq)
+ goto no_request_capture;
+
+ capture = intel_engine_coredump_add_request(ee, rq, ATOMIC_MAYFAIL);
if (!capture) {
-no_request_capture:
- kfree(ee);
- return NULL;
+ i915_request_put(rq);
+ goto no_request_capture;
}
intel_engine_coredump_add_vma(ee, capture, compress);
+ i915_request_put(rq);
return ee;
+
+no_request_capture:
+ kfree(ee);
+ return NULL;
}
static void
*/
error_uc->guc_fw.path = kstrdup(uc->guc.fw.path, ALLOW_FAIL);
error_uc->huc_fw.path = kstrdup(uc->huc.fw.path, ALLOW_FAIL);
- error_uc->guc_log =
- i915_vma_coredump_create(gt->_gt,
- uc->guc.log.vma, "GuC log buffer",
- compress);
+ error_uc->guc_log = create_vma_coredump(gt->_gt, uc->guc.log.vma,
+ "GuC log buffer", compress);
return error_uc;
}
kfree(compress);
}
-struct i915_gpu_coredump *
-i915_gpu_coredump(struct intel_gt *gt, intel_engine_mask_t engine_mask)
+static struct i915_gpu_coredump *
+__i915_gpu_coredump(struct intel_gt *gt, intel_engine_mask_t engine_mask)
{
struct drm_i915_private *i915 = gt->i915;
struct i915_gpu_coredump *error;
return error;
}
+struct i915_gpu_coredump *
+i915_gpu_coredump(struct intel_gt *gt, intel_engine_mask_t engine_mask)
+{
+ static DEFINE_MUTEX(capture_mutex);
+ int ret = mutex_lock_interruptible(&capture_mutex);
+ struct i915_gpu_coredump *dump;
+
+ if (ret)
+ return ERR_PTR(ret);
+
+ dump = __i915_gpu_coredump(gt, engine_mask);
+ mutex_unlock(&capture_mutex);
+
+ return dump;
+}
+
void i915_error_state_store(struct i915_gpu_coredump *error)
{
struct drm_i915_private *i915;
GEM_BUG_ON(rq->guc_prio != GUC_PRIO_INIT &&
rq->guc_prio != GUC_PRIO_FINI);
+ i915_request_free_capture_list(fetch_and_zero(&rq->capture_list));
+ if (i915_vma_snapshot_present(&rq->batch_snapshot))
+ i915_vma_snapshot_put_onstack(&rq->batch_snapshot);
+
/*
* The request is put onto a RCU freelist (i.e. the address
* is immediately reused), mark the fences as being freed now.
__notify_execute_cb(rq, irq_work_imm);
}
-static void free_capture_list(struct i915_request *request)
-{
- struct i915_capture_list *capture;
-
- capture = fetch_and_zero(&request->capture_list);
- while (capture) {
- struct i915_capture_list *next = capture->next;
-
- kfree(capture);
- capture = next;
- }
-}
-
static void __i915_request_fill(struct i915_request *rq, u8 val)
{
void *vaddr = rq->ring->vaddr;
i915_request_put(rq);
}
+#if IS_ENABLED(CONFIG_DRM_I915_CAPTURE_ERROR)
+
+/**
+ * i915_request_free_capture_list - Free a capture list
+ * @capture: Pointer to the first list item or NULL
+ *
+ */
+void i915_request_free_capture_list(struct i915_capture_list *capture)
+{
+ while (capture) {
+ struct i915_capture_list *next = capture->next;
+
+ i915_vma_snapshot_put(capture->vma_snapshot);
+ capture = next;
+ }
+}
+
+#define assert_capture_list_is_null(_rq) GEM_BUG_ON((_rq)->capture_list)
+
+#define clear_capture_list(_rq) ((_rq)->capture_list = NULL)
+
+#else
+
+#define i915_request_free_capture_list(_a) do {} while (0)
+
+#define assert_capture_list_is_null(_a) do {} while (0)
+
+#define clear_capture_list(_rq) do {} while (0)
+
+#endif
+
bool i915_request_retire(struct i915_request *rq)
{
if (!__i915_request_is_complete(rq))
intel_context_exit(rq->context);
intel_context_unpin(rq->context);
- free_capture_list(rq);
i915_sched_node_fini(&rq->sched);
i915_request_put(rq);
i915_sw_fence_init(&rq->submit, submit_notify);
i915_sw_fence_init(&rq->semaphore, semaphore_notify);
- rq->capture_list = NULL;
+ clear_capture_list(rq);
+ rq->batch_snapshot.present = false;
init_llist_head(&rq->execute_cb);
}
+#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
+#define clear_batch_ptr(_rq) ((_rq)->batch = NULL)
+#else
+#define clear_batch_ptr(_a) do {} while (0)
+#endif
+
struct i915_request *
__i915_request_create(struct intel_context *ce, gfp_t gfp)
{
i915_sched_node_reinit(&rq->sched);
/* No zalloc, everything must be cleared after use */
- rq->batch = NULL;
+ clear_batch_ptr(rq);
__rq_init_watchdog(rq);
- GEM_BUG_ON(rq->capture_list);
+ assert_capture_list_is_null(rq);
GEM_BUG_ON(!llist_empty(&rq->execute_cb));
+ GEM_BUG_ON(i915_vma_snapshot_present(&rq->batch_snapshot));
/*
* Reserve space in the ring buffer for all the commands required to
#include "i915_scheduler.h"
#include "i915_selftest.h"
#include "i915_sw_fence.h"
+#include "i915_vma_snapshot.h"
#include <uapi/drm/i915_drm.h>
struct drm_printer;
struct i915_request;
+#if IS_ENABLED(CONFIG_DRM_I915_CAPTURE_ERROR)
struct i915_capture_list {
+ struct i915_vma_snapshot *vma_snapshot;
struct i915_capture_list *next;
- struct i915_vma *vma;
};
+void i915_request_free_capture_list(struct i915_capture_list *capture);
+#else
+#define i915_request_free_capture_list(_a) do {} while (0)
+#endif
+
#define RQ_TRACE(rq, fmt, ...) do { \
const struct i915_request *rq__ = (rq); \
ENGINE_TRACE(rq__->engine, "fence %llx:%lld, current %d " fmt, \
/** Preallocate space in the ring for the emitting the request */
u32 reserved_space;
- /** Batch buffer related to this request if any (used for
- * error state dump only).
- */
- struct i915_vma *batch;
+ /** Batch buffer pointer for selftest internal use. */
+ I915_SELFTEST_DECLARE(struct i915_vma *batch);
+
+ struct i915_vma_snapshot batch_snapshot;
+
+#if IS_ENABLED(CONFIG_DRM_I915_CAPTURE_ERROR)
/**
* Additional buffers requested by userspace to be captured upon
* a GPU hang. The vma/obj on this list are protected by their
* on the active_list (of their final request).
*/
struct i915_capture_list *capture_list;
+#endif
/** Time at which this request was emitted, in jiffies. */
unsigned long emitted_jiffies;
--- /dev/null
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2021 Intel Corporation
+ */
+
+#include "i915_vma_snapshot.h"
+#include "i915_vma_types.h"
+#include "i915_vma.h"
+
+/**
+ * i915_vma_snapshot_init - Initialize a struct i915_vma_snapshot from
+ * a struct i915_vma.
+ * @vsnap: The i915_vma_snapshot to init.
+ * @vma: A struct i915_vma used to initialize @vsnap.
+ * @name: Name associated with the snapshot. The character pointer needs to
+ * stay alive over the lifitime of the shapsot
+ */
+void i915_vma_snapshot_init(struct i915_vma_snapshot *vsnap,
+ struct i915_vma *vma,
+ const char *name)
+{
+ if (!i915_vma_is_pinned(vma))
+ assert_object_held(vma->obj);
+
+ vsnap->name = name;
+ vsnap->size = vma->size;
+ vsnap->obj_size = vma->obj->base.size;
+ vsnap->gtt_offset = vma->node.start;
+ vsnap->gtt_size = vma->node.size;
+ vsnap->page_sizes = vma->page_sizes.gtt;
+ vsnap->pages = vma->pages;
+ vsnap->pages_rsgt = NULL;
+ vsnap->mr = NULL;
+ if (vma->obj->mm.rsgt)
+ vsnap->pages_rsgt = i915_refct_sgt_get(vma->obj->mm.rsgt);
+ vsnap->mr = vma->obj->mm.region;
+ kref_init(&vsnap->kref);
+ vsnap->vma_resource = &vma->active;
+ vsnap->onstack = false;
+ vsnap->present = true;
+}
+
+/**
+ * i915_vma_snapshot_init_onstack - Initialize a struct i915_vma_snapshot from
+ * a struct i915_vma, but avoid kfreeing it on last put.
+ * @vsnap: The i915_vma_snapshot to init.
+ * @vma: A struct i915_vma used to initialize @vsnap.
+ * @name: Name associated with the snapshot. The character pointer needs to
+ * stay alive over the lifitime of the shapsot
+ */
+void i915_vma_snapshot_init_onstack(struct i915_vma_snapshot *vsnap,
+ struct i915_vma *vma,
+ const char *name)
+{
+ i915_vma_snapshot_init(vsnap, vma, name);
+ vsnap->onstack = true;
+}
+
+static void vma_snapshot_release(struct kref *ref)
+{
+ struct i915_vma_snapshot *vsnap =
+ container_of(ref, typeof(*vsnap), kref);
+
+ vsnap->present = false;
+ if (vsnap->pages_rsgt)
+ i915_refct_sgt_put(vsnap->pages_rsgt);
+ if (!vsnap->onstack)
+ kfree(vsnap);
+}
+
+/**
+ * i915_vma_snapshot_put - Put an i915_vma_snapshot pointer reference
+ * @vsnap: The pointer reference
+ */
+void i915_vma_snapshot_put(struct i915_vma_snapshot *vsnap)
+{
+ kref_put(&vsnap->kref, vma_snapshot_release);
+}
+
+/**
+ * i915_vma_snapshot_put_onstack - Put an onstcak i915_vma_snapshot pointer
+ * reference and varify that the structure is released
+ * @vsnap: The pointer reference
+ *
+ * This function is intended to be paired with a i915_vma_init_onstack()
+ * and should be called before exiting the scope that declared or
+ * freeing the structure that embedded @vsnap to verify that all references
+ * have been released.
+ */
+void i915_vma_snapshot_put_onstack(struct i915_vma_snapshot *vsnap)
+{
+ if (!kref_put(&vsnap->kref, vma_snapshot_release))
+ GEM_BUG_ON(1);
+}
+
+/**
+ * i915_vma_snapshot_resource_pin - Temporarily block the memory the
+ * vma snapshot is pointing to from being released.
+ * @vsnap: The vma snapshot.
+ * @lockdep_cookie: Pointer to bool needed for lockdep support. This needs
+ * to be passed to the paired i915_vma_snapshot_resource_unpin.
+ *
+ * This function will temporarily try to hold up a fence or similar structure
+ * and will therefore enter a fence signaling critical section.
+ *
+ * Return: true if we succeeded in blocking the memory from being released,
+ * false otherwise.
+ */
+bool i915_vma_snapshot_resource_pin(struct i915_vma_snapshot *vsnap,
+ bool *lockdep_cookie)
+{
+ bool pinned = i915_active_acquire_if_busy(vsnap->vma_resource);
+
+ if (pinned)
+ *lockdep_cookie = dma_fence_begin_signalling();
+
+ return pinned;
+}
+
+/**
+ * i915_vma_snapshot_resource_unpin - Unblock vma snapshot memory from
+ * being released.
+ * @vsnap: The vma snapshot.
+ * @lockdep_cookie: Cookie returned from matching i915_vma_resource_pin().
+ *
+ * Might leave a fence signalling critical section and signal a fence.
+ */
+void i915_vma_snapshot_resource_unpin(struct i915_vma_snapshot *vsnap,
+ bool lockdep_cookie)
+{
+ dma_fence_end_signalling(lockdep_cookie);
+
+ return i915_active_release(vsnap->vma_resource);
+}
--- /dev/null
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright © 2021 Intel Corporation
+ */
+#ifndef _I915_VMA_SNAPSHOT_H_
+#define _I915_VMA_SNAPSHOT_H_
+
+#include <linux/kref.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+struct i915_active;
+struct i915_refct_sgt;
+struct i915_vma;
+struct intel_memory_region;
+struct sg_table;
+
+/**
+ * DOC: Simple utilities for snapshotting GPU vma metadata, later used for
+ * error capture. Vi use a separate header for this to avoid issues due to
+ * recursive header includes.
+ */
+
+/**
+ * struct i915_vma_snapshot - Snapshot of vma metadata.
+ * @size: The vma size in bytes.
+ * @obj_size: The size of the underlying object in bytes.
+ * @gtt_offset: The gtt offset the vma is bound to.
+ * @gtt_size: The size in bytes allocated for the vma in the GTT.
+ * @pages: The struct sg_table pointing to the pages bound.
+ * @pages_rsgt: The refcounted sg_table holding the reference for @pages if any.
+ * @mr: The memory region pointed for the pages bound.
+ * @kref: Reference for this structure.
+ * @vma_resource: FIXME: A means to keep the unbind fence from signaling.
+ * Temporarily while we have only sync unbinds, and still use the vma
+ * active, we use that. With async unbinding we need a signaling refcount
+ * for the unbind fence.
+ * @page_sizes: The vma GTT page sizes information.
+ * @onstack: Whether the structure shouldn't be freed on final put.
+ * @present: Whether the structure is present and initialized.
+ */
+struct i915_vma_snapshot {
+ const char *name;
+ size_t size;
+ size_t obj_size;
+ size_t gtt_offset;
+ size_t gtt_size;
+ struct sg_table *pages;
+ struct i915_refct_sgt *pages_rsgt;
+ struct intel_memory_region *mr;
+ struct kref kref;
+ struct i915_active *vma_resource;
+ u32 page_sizes;
+ bool onstack:1;
+ bool present:1;
+};
+
+void i915_vma_snapshot_init(struct i915_vma_snapshot *vsnap,
+ struct i915_vma *vma,
+ const char *name);
+
+void i915_vma_snapshot_init_onstack(struct i915_vma_snapshot *vsnap,
+ struct i915_vma *vma,
+ const char *name);
+
+void i915_vma_snapshot_put(struct i915_vma_snapshot *vsnap);
+
+void i915_vma_snapshot_put_onstack(struct i915_vma_snapshot *vsnap);
+
+bool i915_vma_snapshot_resource_pin(struct i915_vma_snapshot *vsnap,
+ bool *lockdep_cookie);
+
+void i915_vma_snapshot_resource_unpin(struct i915_vma_snapshot *vsnap,
+ bool lockdep_cookie);
+
+/**
+ * i915_vma_snapshot_alloc - Allocate a struct i915_vma_snapshot
+ * @gfp: Allocation mode.
+ *
+ * Return: A pointer to a struct i915_vma_snapshot if successful.
+ * NULL otherwise.
+ */
+static inline struct i915_vma_snapshot *i915_vma_snapshot_alloc(gfp_t gfp)
+{
+ return kmalloc(sizeof(struct i915_vma_snapshot), gfp);
+}
+
+/**
+ * i915_vma_snapshot_get - Take a reference on a struct i915_vma_snapshot
+ *
+ * Return: A pointer to a struct i915_vma_snapshot.
+ */
+static inline struct i915_vma_snapshot *
+i915_vma_snapshot_get(struct i915_vma_snapshot *vsnap)
+{
+ kref_get(&vsnap->kref);
+ return vsnap;
+}
+
+/**
+ * i915_vma_snapshot_present - Whether a struct i915_vma_snapshot is
+ * present and initialized.
+ *
+ * Return: true if present and initialized; false otherwise.
+ */
+static inline bool
+i915_vma_snapshot_present(const struct i915_vma_snapshot *vsnap)
+{
+ return vsnap && vsnap->present;
+}
+
+#endif