[Intel-gfx] [RFC 36/38] drm/i915/bdw: begin bitmap tracking
Michel Thierry
michel.thierry at intel.com
Tue Oct 7 19:11:32 CEST 2014
From: Ben Widawsky <benjamin.widawsky at intel.com>
Like with gen6/7, we can enable bitmap tracking with all the
preallocations to make sure things actually don't blow up.
Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
Signed-off-by: Michel Thierry <michel.thierry at intel.com>
---
drivers/gpu/drm/i915/i915_gem_gtt.c | 101 +++++++++++++++++++++++++++++++-----
drivers/gpu/drm/i915/i915_gem_gtt.h | 12 +++++
2 files changed, 99 insertions(+), 14 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index 9403c60..6703721 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -352,8 +352,12 @@ err_out:
static void __free_pd_single(struct i915_pagedir *pd, struct drm_device *dev)
{
+ WARN(!bitmap_empty(pd->used_pdes, I915_PDES_PER_PD),
+ "Free page directory with %d used pages\n",
+ bitmap_weight(pd->used_pdes, I915_PDES_PER_PD));
i915_dma_unmap_single(pd, dev);
__free_page(pd->page);
+ kfree(pd->used_pdes);
kfree(pd);
}
@@ -366,26 +370,35 @@ static void __free_pd_single(struct i915_pagedir *pd, struct drm_device *dev)
static struct i915_pagedir *alloc_pd_single(struct drm_device *dev)
{
struct i915_pagedir *pd;
- int ret;
+ int ret = -ENOMEM;
pd = kzalloc(sizeof(*pd), GFP_KERNEL);
if (!pd)
return ERR_PTR(-ENOMEM);
+ pd->used_pdes = kcalloc(BITS_TO_LONGS(I915_PDES_PER_PD),
+ sizeof(*pd->used_pdes), GFP_KERNEL);
+ if (!pd->used_pdes)
+ goto free_pd;
+
pd->page = alloc_page(GFP_KERNEL | __GFP_ZERO);
- if (!pd->page) {
- kfree(pd);
- return ERR_PTR(-ENOMEM);
- }
+ if (!pd->page)
+ goto free_bitmap;
ret = i915_dma_map_px_single(pd, dev);
- if (ret) {
- __free_page(pd->page);
- kfree(pd);
- return ERR_PTR(ret);
- }
+ if (ret)
+ goto free_page;
return pd;
+
+free_page:
+ __free_page(pd->page);
+free_bitmap:
+ kfree(pd->used_pdes);
+free_pd:
+ kfree(pd);
+
+ return ERR_PTR(ret);
}
/* Broadwell Page Directory Pointer Descriptors */
@@ -566,12 +579,48 @@ static void gen8_teardown_va_range(struct i915_address_space *vm,
gen8_for_each_pdpe(pd, &ppgtt->pdp, start, length, temp, pdpe) {
uint64_t pd_len = gen8_clamp_pd(start, length);
uint64_t pd_start = start;
+
+ /* Page directories might not be present since the macro rounds
+ * down, and up.
+ */
+ if (!pd) {
+ WARN(test_bit(pdpe, ppgtt->pdp.used_pdpes),
+ "PDPE %d is not allocated, but is reserved (%p)\n",
+ pdpe, vm);
+ continue;
+ } else {
+ WARN(!test_bit(pdpe, ppgtt->pdp.used_pdpes),
+ "PDPE %d not reserved, but is allocated (%p)",
+ pdpe, vm);
+ }
+
gen8_for_each_pde(pt, pd, pd_start, pd_len, temp, pde) {
- free_pt_single(pt, vm->dev);
- pd->page_tables[pde] = NULL;
+ if (!pt) {
+ WARN(test_bit(pde, pd->used_pdes),
+ "PDE %d is not allocated, but is reserved (%p)\n",
+ pde, vm);
+ continue;
+ } else
+ WARN(!test_bit(pde, pd->used_pdes),
+ "PDE %d not reserved, but is allocated (%p)",
+ pde, vm);
+
+ bitmap_clear(pt->used_ptes,
+ gen8_pte_index(pd_start),
+ gen8_pte_count(pd_start, pd_len));
+
+ if (bitmap_empty(pt->used_ptes, GEN8_PTES_PER_PT)) {
+ free_pt_single(pt, vm->dev);
+ pd->page_tables[pde] = NULL;
+ WARN_ON(!test_and_clear_bit(pde, pd->used_pdes));
+ }
+ }
+
+ if (bitmap_empty(pd->used_pdes, I915_PDES_PER_PD)) {
+ free_pd_single(pd, vm->dev);
+ ppgtt->pdp.pagedirs[pdpe] = NULL;
+ WARN_ON(!test_and_clear_bit(pdpe, ppgtt->pdp.used_pdpes));
}
- free_pd_single(pd, vm->dev);
- ppgtt->pdp.pagedirs[pdpe] = NULL;
}
}
@@ -614,6 +663,7 @@ unwind_out:
return -ENOMEM;
}
+/* bitmap of new pagedirs */
static int gen8_ppgtt_alloc_pagedirs(struct i915_pagedirpo *pdp,
uint64_t start,
uint64_t length,
@@ -629,6 +679,7 @@ static int gen8_ppgtt_alloc_pagedirs(struct i915_pagedirpo *pdp,
gen8_for_each_pdpe(unused, pdp, start, length, temp, pdpe) {
BUG_ON(unused);
pdp->pagedirs[pdpe] = alloc_pd_single(dev);
+
if (IS_ERR(pdp->pagedirs[pdpe]))
goto unwind_out;
}
@@ -650,10 +701,12 @@ static int gen8_alloc_va_range(struct i915_address_space *vm,
container_of(vm, struct i915_hw_ppgtt, base);
struct i915_pagedir *pd;
const uint64_t orig_start = start;
+ const uint64_t orig_length = length;
uint64_t temp;
uint32_t pdpe;
int ret;
+ /* Do the allocations first so we can easily bail out */
ret = gen8_ppgtt_alloc_pagedirs(&ppgtt->pdp, start, length,
ppgtt->base.dev);
if (ret)
@@ -666,6 +719,26 @@ static int gen8_alloc_va_range(struct i915_address_space *vm,
goto err_out;
}
+ /* Now mark everything we've touched as used. This doesn't allow for
+ * robust error checking, but it makes the code a hell of a lot simpler.
+ */
+ start = orig_start;
+ length = orig_length;
+
+ gen8_for_each_pdpe(pd, &ppgtt->pdp, start, length, temp, pdpe) {
+ struct i915_pagetab *pt;
+ uint64_t pd_len = gen8_clamp_pd(start, length);
+ uint64_t pd_start = start;
+ uint32_t pde;
+ gen8_for_each_pde(pt, &ppgtt->pd, pd_start, pd_len, temp, pde) {
+ bitmap_set(pd->page_tables[pde]->used_ptes,
+ gen8_pte_index(start),
+ gen8_pte_count(start, length));
+ set_bit(pde, pd->used_pdes);
+ }
+ set_bit(pdpe, ppgtt->pdp.used_pdpes);
+ }
+
return 0;
err_out:
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.h b/drivers/gpu/drm/i915/i915_gem_gtt.h
index da27cc4..120f213 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.h
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.h
@@ -193,11 +193,13 @@ struct i915_pagedir {
dma_addr_t daddr;
};
+ unsigned long *used_pdes;
struct i915_pagetab *page_tables[I915_PDES_PER_PD];
};
struct i915_pagedirpo {
/* struct page *page; */
+ DECLARE_BITMAP(used_pdpes, GEN8_LEGACY_PDPES);
struct i915_pagedir *pagedirs[GEN8_LEGACY_PDPES];
};
@@ -459,6 +461,16 @@ static inline uint32_t gen8_pml4e_index(uint64_t address)
BUG();
}
+static inline size_t gen8_pte_count(uint64_t addr, uint64_t length)
+{
+ return i915_pte_count(addr, length, GEN8_PDE_SHIFT);
+}
+
+static inline size_t gen8_pde_count(uint64_t addr, uint64_t length)
+{
+ return i915_pde_count(addr, length, GEN8_PDE_SHIFT);
+}
+
int i915_gem_gtt_init(struct drm_device *dev);
void i915_gem_init_global_gtt(struct drm_device *dev);
int i915_gem_setup_global_gtt(struct drm_device *dev, unsigned long start,
--
2.0.3
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