On Tue, Jun 02, 2020 at 04:06:32PM +1000, Dave Airlie wrote: > Hi Linus, > > This is the main drm pull request for 5.8-rc1. > > Highlights: > Core DRM had a lot of refactoring around managed drm resources to make > drivers simpler. > Intel Tigerlake support is on by default > amdgpu now support p2p PCI buffer sharing and encrypted GPU memory
Christoph Hellwig basically NAK'd this approach, why is it getting merged all of a sudden?? https://lore.kernel.org/intel-gfx/20200311152838.ga24...@infradead.org/ Are we now OK with this same approach open coded in a driver? This wasn't Cc'd to the usual people doing work in this PCI P2P area?? See commit f44ffd677fb3562ac0a1ff9c8ae52672be741f00 Author: Christian König <christian.koe...@amd.com> Date: Fri Mar 23 16:56:37 2018 +0100 drm/amdgpu: add support for exporting VRAM using DMA-buf v3 We should be able to do this now after checking all the prerequisites. v2: fix entrie count in the sgt v3: manually construct the sg Signed-off-by: Christian König <christian.koe...@amd.com> Acked-by: Daniel Vetter <daniel.vet...@ffwll.ch> Acked-by: Sumit Semwal <sumit.sem...@linaro.org> Link: https://patchwork.freedesktop.org/patch/359295 [..] diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c index 82a3299e53c042..128a667ed8fa0d 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c @@ -22,6 +22,7 @@ * Authors: Christian König */ +#include <linux/dma-mapping.h> #include "amdgpu.h" #include "amdgpu_vm.h" #include "amdgpu_atomfirmware.h" @@ -458,6 +459,104 @@ static void amdgpu_vram_mgr_del(struct ttm_mem_type_manager *man, mem->mm_node = NULL; } +/** + * amdgpu_vram_mgr_alloc_sgt - allocate and fill a sg table + * + * @adev: amdgpu device pointer + * @mem: TTM memory object + * @dev: the other device + * @dir: dma direction + * @sgt: resulting sg table + * + * Allocate and fill a sg table from a VRAM allocation. + */ +int amdgpu_vram_mgr_alloc_sgt(struct amdgpu_device *adev, + struct ttm_mem_reg *mem, + struct device *dev, + enum dma_data_direction dir, + struct sg_table **sgt) +{ + struct drm_mm_node *node; + struct scatterlist *sg; + int num_entries = 0; + unsigned int pages; + int i, r; + + *sgt = kmalloc(sizeof(*sg), GFP_KERNEL); + if (!*sgt) + return -ENOMEM; + + for (pages = mem->num_pages, node = mem->mm_node; + pages; pages -= node->size, ++node) + ++num_entries; + + r = sg_alloc_table(*sgt, num_entries, GFP_KERNEL); + if (r) + goto error_free; + + for_each_sg((*sgt)->sgl, sg, num_entries, i) + sg->length = 0; + + node = mem->mm_node; + for_each_sg((*sgt)->sgl, sg, num_entries, i) { + phys_addr_t phys = (node->start << PAGE_SHIFT) + + adev->gmc.aper_base; + size_t size = node->size << PAGE_SHIFT; + dma_addr_t addr; + + ++node; + addr = dma_map_resource(dev, phys, size, dir, + DMA_ATTR_SKIP_CPU_SYNC); + r = dma_mapping_error(dev, addr); + if (r) + goto error_unmap; + + sg_set_page(sg, NULL, size, 0); + sg_dma_address(sg) = addr; + sg_dma_len(sg) = size; ^^^^^^^^^^^^^^ Jason
