Create 3 clear stages in PPGTT init. This will help with upcoming
changes be more readable. The 3 stages are, allocation, dma mapping, and
writing the P[DT]Es
One nice benefit to the patches is that it makes 2 very clear error
points, allocation, and mapping, and avoids having to do any handling
after writing PTEs (something which was likely buggy before). This
simplified error handling I suspect will be helpful when we move to
deferred/dynamic page table allocation and mapping.
The patches also attempts to break up some of the steps into more
logical reviewable chunks, particularly when we free.
v2: Don't call cleanup on the error path since that takes down the
drm_mm and list entry, which aren't setup at this point.
v3: Fixes addressing Imre's comments from:
<1392821989.19792.13.camel@intelbox>
Don't do dynamic allocation for the page table DMA addresses. I can't
remember why I did it in the first place. This addresses one of Imre's
other issues.
Fix error path leak of page tables.
v4: Fix the fix of the error path leak. Original fix still leaked page
tables. (Imre)
Reviewed-by: Imre Deak <imre.deak@xxxxxxxxx>
Signed-off-by: Ben Widawsky <ben@xxxxxxxxxxxx>
---
drivers/gpu/drm/i915/i915_gem_gtt.c | 110 ++++++++++++++++++++----------------
1 file changed, 60 insertions(+), 50 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index e414d7e..7956659 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -333,6 +333,7 @@ static void gen8_ppgtt_free(struct i915_hw_ppgtt *ppgtt)
static void gen8_ppgtt_unmap_pages(struct i915_hw_ppgtt *ppgtt)
{
+ struct pci_dev *hwdev = ppgtt->base.dev->pdev;
int i, j;
for (i = 0; i < ppgtt->num_pd_pages; i++) {
@@ -341,18 +342,14 @@ static void gen8_ppgtt_unmap_pages(struct i915_hw_ppgtt *ppgtt)
if (!ppgtt->pd_dma_addr[i])
continue;
- pci_unmap_page(ppgtt->base.dev->pdev,
- ppgtt->pd_dma_addr[i],
- PAGE_SIZE, PCI_DMA_BIDIRECTIONAL);
+ pci_unmap_page(hwdev, ppgtt->pd_dma_addr[i], PAGE_SIZE,
+ PCI_DMA_BIDIRECTIONAL);
for (j = 0; j < GEN8_PDES_PER_PAGE; j++) {
dma_addr_t addr = ppgtt->gen8_pt_dma_addr[i][j];
if (addr)
- pci_unmap_page(ppgtt->base.dev->pdev,
- addr,
- PAGE_SIZE,
- PCI_DMA_BIDIRECTIONAL);
-
+ pci_unmap_page(hwdev, addr, PAGE_SIZE,
+ PCI_DMA_BIDIRECTIONAL);
}
}
}
@@ -370,27 +367,27 @@ static void gen8_ppgtt_cleanup(struct i915_address_space *vm)
}
/**
- * GEN8 legacy ppgtt programming is accomplished through 4 PDP registers with a
- * net effect resembling a 2-level page table in normal x86 terms. Each PDP
- * represents 1GB of memory
- * 4 * 512 * 512 * 4096 = 4GB legacy 32b address space.
+ * GEN8 legacy ppgtt programming is accomplished through a max 4 PDP registers
+ * with a net effect resembling a 2-level page table in normal x86 terms. Each
+ * PDP represents 1GB of memory 4 * 512 * 512 * 4096 = 4GB legacy 32b address
+ * space.
*
+ * FIXME: split allocation into smaller pieces. For now we only ever do this
+ * once, but with full PPGTT, the multiple contiguous allocations will be bad.
* TODO: Do something with the size parameter
- **/
+ */
static int gen8_ppgtt_init(struct i915_hw_ppgtt *ppgtt, uint64_t size)
{
struct page *pt_pages;
- int i, j, ret = -ENOMEM;
const int max_pdp = DIV_ROUND_UP(size, 1 << 30);
const int num_pt_pages = GEN8_PDES_PER_PAGE * max_pdp;
+ struct pci_dev *hwdev = ppgtt->base.dev->pdev;
+ int i, j, ret;
if (size % (1<<30))
DRM_INFO("Pages will be wasted unless GTT size (%llu) is divisible by 1GB\n", size);
- /* FIXME: split allocation into smaller pieces. For now we only ever do
- * this once, but with full PPGTT, the multiple contiguous allocations
- * will be bad.
- */
+ /* 1. Do all our allocations for page directories and page tables */
ppgtt->pd_pages = alloc_pages(GFP_KERNEL, get_order(max_pdp << PAGE_SHIFT));
if (!ppgtt->pd_pages)
return -ENOMEM;
@@ -405,52 +402,56 @@ static int gen8_ppgtt_init(struct i915_hw_ppgtt *ppgtt, uint64_t size)
ppgtt->num_pd_pages = 1 << get_order(max_pdp << PAGE_SHIFT);
ppgtt->num_pt_pages = 1 << get_order(num_pt_pages << PAGE_SHIFT);
ppgtt->num_pd_entries = max_pdp * GEN8_PDES_PER_PAGE;
- ppgtt->enable = gen8_ppgtt_enable;
- ppgtt->switch_mm = gen8_mm_switch;
- ppgtt->base.clear_range = gen8_ppgtt_clear_range;
- ppgtt->base.insert_entries = gen8_ppgtt_insert_entries;
- ppgtt->base.cleanup = gen8_ppgtt_cleanup;
- ppgtt->base.start = 0;
- ppgtt->base.total = ppgtt->num_pt_pages * GEN8_PTES_PER_PAGE * PAGE_SIZE;
-
BUG_ON(ppgtt->num_pd_pages > GEN8_LEGACY_PDPS);
+ for (i = 0; i < max_pdp; i++) {
+ ppgtt->gen8_pt_dma_addr[i] = kcalloc(GEN8_PDES_PER_PAGE,
+ sizeof(dma_addr_t),
+ GFP_KERNEL);
+ if (!ppgtt->gen8_pt_dma_addr[i]) {
+ ret = -ENOMEM;
+ goto bail;
+ }
+ }
+
/*
- * - Create a mapping for the page directories.
- * - For each page directory:
- * allocate space for page table mappings.
- * map each page table
+ * 2. Create all the DMA mappings for the page directories and page
+ * tables
*/
for (i = 0; i < max_pdp; i++) {
- dma_addr_t temp;
- temp = pci_map_page(ppgtt->base.dev->pdev,
- &ppgtt->pd_pages[i], 0,
- PAGE_SIZE, PCI_DMA_BIDIRECTIONAL);
- if (pci_dma_mapping_error(ppgtt->base.dev->pdev, temp))
- goto err_out;
+ dma_addr_t pd_addr, pt_addr;
- ppgtt->pd_dma_addr[i] = temp;
+ /* Get the page directory mappings */
+ pd_addr = pci_map_page(hwdev, &ppgtt->pd_pages[i], 0,
+ PAGE_SIZE, PCI_DMA_BIDIRECTIONAL);
+ ret = pci_dma_mapping_error(ppgtt->base.dev->pdev, pd_addr);
+ if (ret)
+ goto bail;
- ppgtt->gen8_pt_dma_addr[i] = kmalloc(sizeof(dma_addr_t) * GEN8_PDES_PER_PAGE, GFP_KERNEL);
- if (!ppgtt->gen8_pt_dma_addr[i])
- goto err_out;
+ ppgtt->pd_dma_addr[i] = pd_addr;
+ /* And the page table mappings per page directory */
for (j = 0; j < GEN8_PDES_PER_PAGE; j++) {
struct page *p = &pt_pages[i * GEN8_PDES_PER_PAGE + j];
- temp = pci_map_page(ppgtt->base.dev->pdev,
- p, 0, PAGE_SIZE,
- PCI_DMA_BIDIRECTIONAL);
- if (pci_dma_mapping_error(ppgtt->base.dev->pdev, temp))
- goto err_out;
+ pt_addr = pci_map_page(hwdev, p, 0, PAGE_SIZE,
+ PCI_DMA_BIDIRECTIONAL);
+ ret = pci_dma_mapping_error(hwdev, pt_addr);
+ if (ret)
+ goto bail;
- ppgtt->gen8_pt_dma_addr[i][j] = temp;
+ ppgtt->gen8_pt_dma_addr[i][j] = pt_addr;
}
}
- /* For now, the PPGTT helper functions all require that the PDEs are
+ /*
+ * 3. Map all the page directory entires to point to the page tables
+ * we've allocated.
+ *
+ * For now, the PPGTT helper functions all require that the PDEs are
* plugged in correctly. So we do that now/here. For aliasing PPGTT, we
- * will never need to touch the PDEs again */
+ * will never need to touch the PDEs again.
+ */
for (i = 0; i < max_pdp; i++) {
gen8_ppgtt_pde_t *pd_vaddr;
pd_vaddr = kmap_atomic(&ppgtt->pd_pages[i]);
@@ -462,6 +463,14 @@ static int gen8_ppgtt_init(struct i915_hw_ppgtt *ppgtt, uint64_t size)
kunmap_atomic(pd_vaddr);
}
+ ppgtt->enable = gen8_ppgtt_enable;
+ ppgtt->switch_mm = gen8_mm_switch;
+ ppgtt->base.clear_range = gen8_ppgtt_clear_range;
+ ppgtt->base.insert_entries = gen8_ppgtt_insert_entries;
+ ppgtt->base.cleanup = gen8_ppgtt_cleanup;
+ ppgtt->base.start = 0;
+ ppgtt->base.total = ppgtt->num_pt_pages * GEN8_PTES_PER_PAGE * PAGE_SIZE;
+
ppgtt->base.clear_range(&ppgtt->base, 0,
ppgtt->num_pd_entries * GEN8_PTES_PER_PAGE,
true);
@@ -474,8 +483,9 @@ static int gen8_ppgtt_init(struct i915_hw_ppgtt *ppgtt, uint64_t size)
size % (1<<30));
return 0;
-err_out:
- ppgtt->base.cleanup(&ppgtt->base);
+bail:
+ gen8_ppgtt_unmap_pages(ppgtt);
+ gen8_ppgtt_free(ppgtt);
return ret;
}
--
1.9.0
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