From f3a964b96d792eac67976a3bb296a0d2049b4f91 Mon Sep 17 00:00:00 2001 From: Ben Widawsky Date: Wed, 19 Feb 2014 22:05:42 -0800 Subject: [PATCH] drm/i915/bdw: Reorganize PPGTT init 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 Signed-off-by: Ben Widawsky Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/i915_gem_gtt.c | 128 +++++++++++++++------------- 1 file changed, 69 insertions(+), 59 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c index 49e79fbee45d..2bc07fb447bd 100644 --- a/drivers/gpu/drm/i915/i915_gem_gtt.c +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c @@ -332,6 +332,7 @@ 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++) { @@ -340,18 +341,14 @@ 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); } } } @@ -369,27 +366,27 @@ 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; @@ -404,52 +401,56 @@ 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); - /* - * - Create a mapping for the page directories. - * - For each page directory: - * allocate space for page table mappings. - * map each page table - */ 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; - - ppgtt->pd_dma_addr[i] = temp; - - 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; - - 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; - - ppgtt->gen8_pt_dma_addr[i][j] = temp; + 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; } } - /* For now, the PPGTT helper functions all require that the PDEs are + /* + * 2. Create all the DMA mappings for the page directories and page + * tables + */ + for (i = 0; i < max_pdp; i++) { + dma_addr_t pd_addr, pt_addr; + + /* 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->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]; + + 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] = pt_addr; + } + } + + /* + * 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]); @@ -461,6 +462,14 @@ 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); @@ -473,8 +482,9 @@ 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; }