[RFC 13/13] drm/i915/svm: Add page table dump support
Niranjana Vishwanathapura
niranjana.vishwanathapura at intel.com
Fri Nov 22 20:57:34 UTC 2019
Add support to dump page table for debug purpose.
Here is an example dump. Format is,
[<page table index>] <start VA pfn>: <value>
Page Table dump start 0x0 len 0xffffffffffffffff
[0x0fe] 0x7f0000000: 0x6b0003
[0x1e6] 0x7f7980000: 0x6c0003
[0x16d] 0x7f79ada00: 0x5f0003
[0x000] 0x7f79ada00: 0x610803
[0x16e] 0x7f79adc00: 0x6d0003
[0x000] 0x7f79adc00: 0x630803
[0x100] 0x800000000: 0x6f0003
[0x000] 0x800000000: 0x700000
[0x000] 0x800000000: 0x710003
[0x000] 0x800000000: 0x5d0803
Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
Cc: Jon Bloomfield <jon.bloomfield at intel.com>
Cc: Daniel Vetter <daniel.vetter at intel.com>
Cc: Sudeep Dutt <sudeep.dutt at intel.com>
Signed-off-by: Niranjana Vishwanathapura <niranjana.vishwanathapura at intel.com>
---
drivers/gpu/drm/i915/Kconfig.debug | 14 +++
.../gpu/drm/i915/gem/i915_gem_execbuffer.c | 1 +
drivers/gpu/drm/i915/i915_gem_gtt.c | 92 +++++++++++++++++++
drivers/gpu/drm/i915/i915_gem_gtt.h | 14 +++
4 files changed, 121 insertions(+)
diff --git a/drivers/gpu/drm/i915/Kconfig.debug b/drivers/gpu/drm/i915/Kconfig.debug
index 1140525da75a..06953c1d6fd4 100644
--- a/drivers/gpu/drm/i915/Kconfig.debug
+++ b/drivers/gpu/drm/i915/Kconfig.debug
@@ -223,3 +223,17 @@ config DRM_I915_DEBUG_RUNTIME_PM
driver loading, suspend and resume operations.
If in doubt, say "N"
+
+config DRM_I915_DUMP_PPGTT
+ bool "Enable PPGTT Page Table dump support"
+ depends on DRM_I915
+ default n
+ help
+ Choose this option to enable PPGTT page table dump support.
+ The page table snapshot helps developers to debug page table
+ related issues. This will affect performance and dumps a lot of
+ information, so only recommended for developer debug.
+
+ Recommended for driver developers only.
+
+ If in doubt, say "N".
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
index cbcfbf86ea61..c771659d72e2 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -2707,6 +2707,7 @@ i915_gem_do_execbuffer(struct drm_device *dev,
intel_engine_pool_mark_active(eb.batch->private, eb.request);
trace_i915_request_queue(eb.request, eb.batch_flags);
+ ppgtt_dump(eb.context->vm, 0, eb.context->vm->total);
err = eb_submit(&eb);
err_request:
add_to_client(eb.request, file);
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index 08cbbb4d91cb..6a7348af5717 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -1215,6 +1215,97 @@ static int gen8_ppgtt_alloc(struct i915_address_space *vm,
return err;
}
+#ifdef CONFIG_DRM_I915_DUMP_PPGTT
+static void __gen8_ppgtt_dump(struct i915_address_space * const vm,
+ struct i915_page_directory * const pd,
+ u64 start, u64 end, int lvl)
+{
+ char *prefix[4] = { "\t\t\t\t", "\t\t\t", "\t\t", "\t"};
+ char *format = "%s [0x%03x] 0x%llx: 0x%llx\n";
+ unsigned int idx, len;
+ gen8_pte_t *vaddr;
+ unsigned int pdpe;
+ bool is_large;
+
+ GEM_BUG_ON(end > vm->total >> GEN8_PTE_SHIFT);
+
+ len = gen8_pd_range(start, end, lvl--, &idx);
+ GEM_BUG_ON(!len || (idx + len - 1) >> gen8_pd_shift(1));
+
+ spin_lock(&pd->lock);
+ GEM_BUG_ON(!atomic_read(px_used(pd))); /* Must be pinned! */
+ do {
+ struct i915_page_table *pt = pd->entry[idx];
+
+ if (!pt) {
+ start += (1 << gen8_pd_shift(lvl + 1));
+ continue;
+ }
+
+ vaddr = kmap_atomic_px(&pd->pt);
+ pdpe = gen8_pd_index(start, lvl + 1);
+ DRM_DEBUG_DRIVER(format, prefix[lvl + 1], pdpe,
+ start, vaddr[pdpe]);
+ is_large = (vaddr[pdpe] & GEN8_PDE_PS_2M);
+ kunmap_atomic(vaddr);
+ if (is_large) {
+ start += (1 << gen8_pd_shift(lvl + 1));
+ continue;
+ }
+
+ if (lvl) {
+ atomic_inc(&pt->used);
+ spin_unlock(&pd->lock);
+
+ __gen8_ppgtt_dump(vm, as_pd(pt),
+ start, end, lvl);
+
+ start += (1 << gen8_pd_shift(lvl + 1));
+ spin_lock(&pd->lock);
+ atomic_dec(&pt->used);
+ GEM_BUG_ON(!atomic_read(&pt->used));
+ } else {
+ unsigned int count = gen8_pt_count(start, end);
+
+ pdpe = gen8_pd_index(start, lvl);
+ vaddr = kmap_atomic_px(pt);
+ while (count) {
+ if (vaddr[pdpe] != vm->scratch[lvl].encode)
+ DRM_DEBUG_DRIVER(format, prefix[lvl],
+ pdpe, start,
+ vaddr[pdpe]);
+ start++;
+ count--;
+ pdpe++;
+ }
+
+ kunmap_atomic(vaddr);
+ GEM_BUG_ON(atomic_read(&pt->used) > I915_PDES);
+ }
+ } while (idx++, --len);
+ spin_unlock(&pd->lock);
+}
+
+static void gen8_ppgtt_dump(struct i915_address_space *vm,
+ u64 start, u64 length)
+{
+ GEM_BUG_ON(!IS_ALIGNED(start, BIT_ULL(GEN8_PTE_SHIFT)));
+ GEM_BUG_ON(!IS_ALIGNED(length, BIT_ULL(GEN8_PTE_SHIFT)));
+ GEM_BUG_ON(range_overflows(start, length, vm->total));
+
+ start >>= GEN8_PTE_SHIFT;
+ length >>= GEN8_PTE_SHIFT;
+ GEM_BUG_ON(length == 0);
+
+ DRM_DEBUG_DRIVER("PPGTT dump: start 0x%llx length 0x%llx\n",
+ start, length);
+ __gen8_ppgtt_dump(vm, i915_vm_to_ppgtt(vm)->pd,
+ start, start + length, vm->top);
+}
+#else
+#define gen8_ppgtt_dump NULL
+#endif
+
static inline struct sgt_dma {
struct scatterlist *sg;
dma_addr_t dma, max;
@@ -1584,6 +1675,7 @@ static struct i915_ppgtt *gen8_ppgtt_create(struct drm_i915_private *i915)
ppgtt->vm.insert_entries = gen8_ppgtt_insert;
ppgtt->vm.allocate_va_range = gen8_ppgtt_alloc;
ppgtt->vm.clear_range = gen8_ppgtt_clear;
+ ppgtt->vm.dump_va_range = gen8_ppgtt_dump;
if (intel_vgpu_active(i915))
gen8_ppgtt_notify_vgt(ppgtt, true);
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.h b/drivers/gpu/drm/i915/i915_gem_gtt.h
index 722b1e7ce291..a4358fb1c711 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.h
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.h
@@ -367,6 +367,8 @@ struct i915_address_space {
u64 start, u64 length);
void (*clear_range)(struct i915_address_space *vm,
u64 start, u64 length);
+ void (*dump_va_range)(struct i915_address_space *vm,
+ u64 start, u64 length);
void (*insert_page)(struct i915_address_space *vm,
dma_addr_t addr,
u64 offset,
@@ -683,6 +685,18 @@ int i915_gem_gtt_insert(struct i915_address_space *vm,
#define PIN_OFFSET_MASK (-I915_GTT_PAGE_SIZE)
+#ifdef CONFIG_DRM_I915_DUMP_PPGTT
+static inline void ppgtt_dump(struct i915_address_space *vm,
+ u64 start, u64 length)
+{
+ if (vm->dump_va_range)
+ vm->dump_va_range(vm, start, length);
+}
+#else
+static inline void ppgtt_dump(struct i915_address_space *vm,
+ u64 start, u64 length) { }
+#endif
+
/* SVM API */
#define I915_GTT_SVM_READONLY BIT(0)
--
2.21.0.rc0.32.g243a4c7e27
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