diff --git a/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c b/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c
index 7fc46861a54d51b48cb09baee4f8e617d6b4f602..130c4c5226863c3a1b94928c929b1fe6e8d361c7 100644
--- a/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c
@@ -1492,6 +1492,10 @@ static int write_to_scratch(struct i915_gem_context *ctx,
GEM_BUG_ON(offset < I915_GTT_PAGE_SIZE);
+ err = check_scratch(ctx_vm(ctx), offset);
+ if (err)
+ return err;
+
obj = i915_gem_object_create_internal(i915, PAGE_SIZE);
if (IS_ERR(obj))
return PTR_ERR(obj);
@@ -1528,10 +1532,6 @@ static int write_to_scratch(struct i915_gem_context *ctx,
if (err)
goto out_vm;
- err = check_scratch(vm, offset);
- if (err)
- goto err_unpin;
-
rq = igt_request_alloc(ctx, engine);
if (IS_ERR(rq)) {
err = PTR_ERR(rq);
@@ -1575,64 +1575,95 @@ static int read_from_scratch(struct i915_gem_context *ctx,
struct drm_i915_private *i915 = ctx->i915;
struct drm_i915_gem_object *obj;
struct i915_address_space *vm;
- const u32 RCS_GPR0 = 0x2600; /* not all engines have their own GPR! */
const u32 result = 0x100;
struct i915_request *rq;
struct i915_vma *vma;
+ unsigned int flags;
u32 *cmd;
int err;
GEM_BUG_ON(offset < I915_GTT_PAGE_SIZE);
+ err = check_scratch(ctx_vm(ctx), offset);
+ if (err)
+ return err;
+
obj = i915_gem_object_create_internal(i915, PAGE_SIZE);
if (IS_ERR(obj))
return PTR_ERR(obj);
- cmd = i915_gem_object_pin_map(obj, I915_MAP_WB);
- if (IS_ERR(cmd)) {
- err = PTR_ERR(cmd);
- goto out;
- }
-
- memset(cmd, POISON_INUSE, PAGE_SIZE);
if (INTEL_GEN(i915) >= 8) {
+ const u32 GPR0 = engine->mmio_base + 0x600;
+
+ vm = i915_gem_context_get_vm_rcu(ctx);
+ vma = i915_vma_instance(obj, vm, NULL);
+ if (IS_ERR(vma)) {
+ err = PTR_ERR(vma);
+ goto out_vm;
+ }
+
+ err = i915_vma_pin(vma, 0, 0, PIN_USER | PIN_OFFSET_FIXED);
+ if (err)
+ goto out_vm;
+
+ cmd = i915_gem_object_pin_map(obj, I915_MAP_WB);
+ if (IS_ERR(cmd)) {
+ err = PTR_ERR(cmd);
+ goto out;
+ }
+
+ memset(cmd, POISON_INUSE, PAGE_SIZE);
*cmd++ = MI_LOAD_REGISTER_MEM_GEN8;
- *cmd++ = RCS_GPR0;
+ *cmd++ = GPR0;
*cmd++ = lower_32_bits(offset);
*cmd++ = upper_32_bits(offset);
*cmd++ = MI_STORE_REGISTER_MEM_GEN8;
- *cmd++ = RCS_GPR0;
+ *cmd++ = GPR0;
*cmd++ = result;
*cmd++ = 0;
+ *cmd = MI_BATCH_BUFFER_END;
+
+ i915_gem_object_flush_map(obj);
+ i915_gem_object_unpin_map(obj);
+
+ flags = 0;
} else {
+ const u32 reg = engine->mmio_base + 0x420;
+
+ /* hsw: register access even to 3DPRIM! is protected */
+ vm = i915_vm_get(&engine->gt->ggtt->vm);
+ vma = i915_vma_instance(obj, vm, NULL);
+ if (IS_ERR(vma)) {
+ err = PTR_ERR(vma);
+ goto out_vm;
+ }
+
+ err = i915_vma_pin(vma, 0, 0, PIN_GLOBAL);
+ if (err)
+ goto out_vm;
+
+ cmd = i915_gem_object_pin_map(obj, I915_MAP_WB);
+ if (IS_ERR(cmd)) {
+ err = PTR_ERR(cmd);
+ goto out;
+ }
+
+ memset(cmd, POISON_INUSE, PAGE_SIZE);
*cmd++ = MI_LOAD_REGISTER_MEM;
- *cmd++ = RCS_GPR0;
+ *cmd++ = reg;
*cmd++ = offset;
- *cmd++ = MI_STORE_REGISTER_MEM;
- *cmd++ = RCS_GPR0;
- *cmd++ = result;
- }
- *cmd = MI_BATCH_BUFFER_END;
-
- i915_gem_object_flush_map(obj);
- i915_gem_object_unpin_map(obj);
+ *cmd++ = MI_STORE_REGISTER_MEM | MI_USE_GGTT;
+ *cmd++ = reg;
+ *cmd++ = vma->node.start + result;
+ *cmd = MI_BATCH_BUFFER_END;
- intel_gt_chipset_flush(engine->gt);
+ i915_gem_object_flush_map(obj);
+ i915_gem_object_unpin_map(obj);
- vm = i915_gem_context_get_vm_rcu(ctx);
- vma = i915_vma_instance(obj, vm, NULL);
- if (IS_ERR(vma)) {
- err = PTR_ERR(vma);
- goto out_vm;
+ flags = I915_DISPATCH_SECURE;
}
- err = i915_vma_pin(vma, 0, 0, PIN_USER | PIN_OFFSET_FIXED);
- if (err)
- goto out_vm;
-
- err = check_scratch(vm, offset);
- if (err)
- goto err_unpin;
+ intel_gt_chipset_flush(engine->gt);
rq = igt_request_alloc(ctx, engine);
if (IS_ERR(rq)) {
@@ -1640,7 +1671,7 @@ static int read_from_scratch(struct i915_gem_context *ctx,
goto err_unpin;
}
- err = engine->emit_bb_start(rq, vma->node.start, vma->node.size, 0);
+ err = engine->emit_bb_start(rq, vma->node.start, vma->node.size, flags);
if (err)
goto err_request;
@@ -1686,6 +1717,39 @@ static int read_from_scratch(struct i915_gem_context *ctx,
return err;
}
+static int check_scratch_page(struct i915_gem_context *ctx, u32 *out)
+{
+ struct i915_address_space *vm;
+ struct page *page;
+ u32 *vaddr;
+ int err = 0;
+
+ vm = ctx_vm(ctx);
+ if (!vm)
+ return -ENODEV;
+
+ page = vm->scratch[0].base.page;
+ if (!page) {
+ pr_err("No scratch page!\n");
+ return -EINVAL;
+ }
+
+ vaddr = kmap(page);
+ if (!vaddr) {
+ pr_err("No (mappable) scratch page!\n");
+ return -EINVAL;
+ }
+
+ memcpy(out, vaddr, sizeof(*out));
+ if (memchr_inv(vaddr, *out, PAGE_SIZE)) {
+ pr_err("Inconsistent initial state of scratch page!\n");
+ err = -EINVAL;
+ }
+ kunmap(page);
+
+ return err;
+}
+
static int igt_vm_isolation(void *arg)
{
struct drm_i915_private *i915 = arg;
@@ -1696,6 +1760,7 @@ static int igt_vm_isolation(void *arg)
I915_RND_STATE(prng);
struct file *file;
u64 vm_total;
+ u32 expected;
int err;
if (INTEL_GEN(i915) < 7)
@@ -1730,6 +1795,15 @@ static int igt_vm_isolation(void *arg)
if (ctx_vm(ctx_a) == ctx_vm(ctx_b))
goto out_file;
+ /* Read the initial state of the scratch page */
+ err = check_scratch_page(ctx_a, &expected);
+ if (err)
+ goto out_file;
+
+ err = check_scratch_page(ctx_b, &expected);
+ if (err)
+ goto out_file;
+
vm_total = ctx_vm(ctx_a)->total;
GEM_BUG_ON(ctx_vm(ctx_b)->total != vm_total);
vm_total -= I915_GTT_PAGE_SIZE;
@@ -1743,6 +1817,10 @@ static int igt_vm_isolation(void *arg)
if (!intel_engine_can_store_dword(engine))
continue;
+ /* Not all engines have their own GPR! */
+ if (INTEL_GEN(i915) < 8 && engine->class != RENDER_CLASS)
+ continue;
+
while (!__igt_timeout(end_time, NULL)) {
u32 value = 0xc5c5c5c5;
u64 offset;
@@ -1760,7 +1838,7 @@ static int igt_vm_isolation(void *arg)
if (err)
goto out_file;
- if (value) {
+ if (value != expected) {
pr_err("%s: Read %08x from scratch (offset 0x%08x_%08x), after %lu reads!\n",
engine->name, value,
upper_32_bits(offset),
diff --git a/drivers/gpu/drm/i915/gt/intel_gtt.c b/drivers/gpu/drm/i915/gt/intel_gtt.c
index 45d8e0019a8e1552ae294cb012cba3ec56242335..bb9a6e6381757277d70e4e9e9dea4b3de6c1ed7f 100644
--- a/drivers/gpu/drm/i915/gt/intel_gtt.c
+++ b/drivers/gpu/drm/i915/gt/intel_gtt.c
@@ -299,6 +299,25 @@ fill_page_dma(const struct i915_page_dma *p, const u64 val, unsigned int count)
kunmap_atomic(memset64(kmap_atomic(p->page), val, count));
}
+static void poison_scratch_page(struct page *page, unsigned long size)
+{
+ if (!IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM))
+ return;
+
+ GEM_BUG_ON(!IS_ALIGNED(size, PAGE_SIZE));
+
+ do {
+ void *vaddr;
+
+ vaddr = kmap(page);
+ memset(vaddr, POISON_FREE, PAGE_SIZE);
+ kunmap(page);
+
+ page = pfn_to_page(page_to_pfn(page) + 1);
+ size -= PAGE_SIZE;
+ } while (size);
+}
+
int setup_scratch_page(struct i915_address_space *vm, gfp_t gfp)
{
unsigned long size;
@@ -331,6 +350,17 @@ int setup_scratch_page(struct i915_address_space *vm, gfp_t gfp)
if (unlikely(!page))
goto skip;
+ /*
+ * Use a non-zero scratch page for debugging.
+ *
+ * We want a value that should be reasonably obvious
+ * to spot in the error state, while also causing a GPU hang
+ * if executed. We prefer using a clear page in production, so
+ * should it ever be accidentally used, the effect should be
+ * fairly benign.
+ */
+ poison_scratch_page(page, size);
+
addr = dma_map_page_attrs(vm->dma,
page, 0, size,
PCI_DMA_BIDIRECTIONAL,