CMA-allocated memory must be freed by an exact mirror call to dma_release_from_contiguous(). It cannot be freed page-by-page as was previously believed without severe memory leakage.
This page records the address and size of every allocated memory chunk so they can be properly freed when needed.
Signed-off-by: Alexandre Courbot acourbot@nvidia.com --- drivers/gpu/drm/nouveau/core/subdev/fb/ramgk20a.c | 74 ++++++++++++++--------- 1 file changed, 46 insertions(+), 28 deletions(-)
diff --git a/drivers/gpu/drm/nouveau/core/subdev/fb/ramgk20a.c b/drivers/gpu/drm/nouveau/core/subdev/fb/ramgk20a.c index 7effd1a63458..5904af52e6d6 100644 --- a/drivers/gpu/drm/nouveau/core/subdev/fb/ramgk20a.c +++ b/drivers/gpu/drm/nouveau/core/subdev/fb/ramgk20a.c @@ -28,28 +28,34 @@ #include <linux/types.h> #include <linux/dma-contiguous.h>
+struct gk20a_mem_chunk { + struct list_head list; + struct page *pages; + u32 npages; +}; + +struct gk20a_mem { + struct nouveau_mem base; + struct list_head head; +}; + static void gk20a_ram_put(struct nouveau_fb *pfb, struct nouveau_mem **pmem) { struct device *dev = nv_device_base(nv_device(pfb)); - struct nouveau_mem *mem = *pmem; - int i; + struct gk20a_mem *mem = container_of(*pmem, struct gk20a_mem, base); + struct gk20a_mem_chunk *chunk, *n;
*pmem = NULL; if (unlikely(mem == NULL)) return;
- for (i = 0; i < mem->size; i++) { - struct page *page; - - if (mem->pages[i] == 0) - break; - - page = pfn_to_page(mem->pages[i] >> PAGE_SHIFT); - dma_release_from_contiguous(dev, page, 1); + list_for_each_entry_safe(chunk, n, &mem->head, list) { + dma_release_from_contiguous(dev, chunk->pages, chunk->npages); + kfree(chunk); }
- kfree(mem->pages); + kfree(mem->base.pages); kfree(mem); }
@@ -58,9 +64,8 @@ gk20a_ram_get(struct nouveau_fb *pfb, u64 size, u32 align, u32 ncmin, u32 memtype, struct nouveau_mem **pmem) { struct device *dev = nv_device_base(nv_device(pfb)); - struct nouveau_mem *mem; + struct gk20a_mem *mem; int type = memtype & 0xff; - dma_addr_t dma_addr; int npages; int order; int i; @@ -95,44 +100,57 @@ gk20a_ram_get(struct nouveau_fb *pfb, u64 size, u32 align, u32 ncmin, if (!mem) return -ENOMEM;
- mem->size = npages; - mem->memtype = type; + mem->base.size = npages; + mem->base.memtype = type;
- mem->pages = kzalloc(sizeof(dma_addr_t) * npages, GFP_KERNEL); - if (!mem) { + mem->base.pages = kzalloc(sizeof(dma_addr_t) * npages, GFP_KERNEL); + if (!mem->base.pages) { kfree(mem); return -ENOMEM; }
+ INIT_LIST_HEAD(&mem->head); + + *pmem = &mem->base; + while (npages) { - struct page *pages; + struct gk20a_mem_chunk *chunk; + dma_addr_t addr; int pos = 0;
/* don't overflow in case size is not a multiple of ncmin */ if (ncmin > npages) ncmin = npages;
- pages = dma_alloc_from_contiguous(dev, ncmin, order); - if (!pages) { - gk20a_ram_put(pfb, &mem); + chunk = kzalloc(sizeof(*chunk), GFP_KERNEL); + if (!chunk) { + gk20a_ram_put(pfb, pmem); return -ENOMEM; }
- dma_addr = (dma_addr_t)(page_to_pfn(pages) << PAGE_SHIFT); + chunk->pages = dma_alloc_from_contiguous(dev, ncmin, order); + if (!chunk->pages) { + kfree(chunk); + gk20a_ram_put(pfb, pmem); + return -ENOMEM; + }
- nv_debug(pfb, " alloc count: %x, order: %x, addr: %pad\n", ncmin, - order, &dma_addr); + chunk->npages = ncmin; + list_add_tail(&chunk->list, &mem->head); + + addr = (dma_addr_t)(page_to_pfn(chunk->pages) << PAGE_SHIFT); + + nv_debug(pfb, " alloc count: %x, order: %x, addr: %pad\n", + ncmin, order, &addr);
for (i = 0; i < ncmin; i++) - mem->pages[pos + i] = dma_addr + (PAGE_SIZE * i); + mem->base.pages[pos + i] = addr + (PAGE_SIZE * i);
pos += ncmin; npages -= ncmin; }
- mem->offset = (u64)mem->pages[0]; - - *pmem = mem; + mem->base.offset = (u64)mem->base.pages[0];
return 0; }