drm/nouveau/nvkm: support loading fws into sg_table

- preparation for GSP-RM, which has massive FW images
- based on a patch by Dave Airlie

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230918202149.4343-32-skeggsb@gmail.com

drivers/gpu/drm/nouveau/include/nvkm/core/firmware.h

@@ -10,6 +10,7 @@ struct nvkm_firmware {
  enum nvkm_firmware_type {
  NVKM_FIRMWARE_IMG_RAM,
  NVKM_FIRMWARE_IMG_DMA,
+ NVKM_FIRMWARE_IMG_SGT,
  } type;
  } *func;
  const char *name;
@@ -21,7 +22,10 @@ struct nvkm_firmware {
 
  struct nvkm_firmware_mem {
  struct nvkm_memory memory;
- struct scatterlist sgl;
+ union {
+ struct scatterlist sgl; /* DMA */
+ struct sg_table sgt; /* SGT */
+ };
  } mem;
 };
 

drivers/gpu/drm/nouveau/nvkm/core/firmware.c

@@ -112,6 +112,22 @@ nvkm_firmware_put(const struct firmware *fw)
 
 #define nvkm_firmware_mem(p) container_of((p), struct nvkm_firmware, mem.memory)
 
+static struct scatterlist *
+nvkm_firmware_mem_sgl(struct nvkm_memory *memory)
+{
+ struct nvkm_firmware *fw = nvkm_firmware_mem(memory);
+
+ switch (fw->func->type) {
+ case NVKM_FIRMWARE_IMG_DMA: return &fw->mem.sgl;
+ case NVKM_FIRMWARE_IMG_SGT: return fw->mem.sgt.sgl;
+ default:
+ WARN_ON(1);
+ break;
+ }
+
+ return NULL;
+}
+
 static int
 nvkm_firmware_mem_map(struct nvkm_memory *memory, u64 offset, struct nvkm_vmm *vmm,
  struct nvkm_vma *vma, void *argv, u32 argc)
@@ -120,10 +136,10 @@ nvkm_firmware_mem_map(struct nvkm_memory *memory, u64 offset, struct nvkm_vmm *v
  struct nvkm_vmm_map map = {
  .memory = &fw->mem.memory,
  .offset = offset,
- .sgl = &fw->mem.sgl,
+ .sgl = nvkm_firmware_mem_sgl(memory),
  };
 
- if (WARN_ON(fw->func->type != NVKM_FIRMWARE_IMG_DMA))
+ if (!map.sgl)
  return -ENOSYS;
 
  return nvkm_vmm_map(vmm, vma, argv, argc, &map);
@@ -132,12 +148,15 @@ nvkm_firmware_mem_map(struct nvkm_memory *memory, u64 offset, struct nvkm_vmm *v
 static u64
 nvkm_firmware_mem_size(struct nvkm_memory *memory)
 {
- return sg_dma_len(&nvkm_firmware_mem(memory)->mem.sgl);
+ struct scatterlist *sgl = nvkm_firmware_mem_sgl(memory);
+
+ return sgl ? sg_dma_len(sgl) : 0;
 }
 
 static u64
 nvkm_firmware_mem_addr(struct nvkm_memory *memory)
 {
+ BUG_ON(nvkm_firmware_mem(memory)->func->type != NVKM_FIRMWARE_IMG_DMA);
  return nvkm_firmware_mem(memory)->phys;
 }
 
@@ -188,6 +207,12 @@ nvkm_firmware_dtor(struct nvkm_firmware *fw)
  nvkm_memory_unref(&memory);
  dma_free_coherent(fw->device->dev, sg_dma_len(&fw->mem.sgl), fw->img, fw->phys);
  break;
+ case NVKM_FIRMWARE_IMG_SGT:
+ nvkm_memory_unref(&memory);
+ dma_unmap_sgtable(fw->device->dev, &fw->mem.sgt, DMA_TO_DEVICE, 0);
+ sg_free_table(&fw->mem.sgt);
+ vfree(fw->img);
+ break;
  default:
  WARN_ON(1);
  break;
@@ -225,6 +250,49 @@ nvkm_firmware_ctor(const struct nvkm_firmware_func *func, const char *name,
  sg_dma_len(&fw->mem.sgl) = len;
  }
  break;
+ case NVKM_FIRMWARE_IMG_SGT:
+ len = ALIGN(fw->len, PAGE_SIZE);
+
+ fw->img = vmalloc(len);
+ if (fw->img) {
+ int pages = len >> PAGE_SHIFT;
+ int ret = 0;
+
+ memcpy(fw->img, src, fw->len);
+
+ ret = sg_alloc_table(&fw->mem.sgt, pages, GFP_KERNEL);
+ if (ret == 0) {
+ struct scatterlist *sgl;
+ u8 *data = fw->img;
+ int i;
+
+ for_each_sgtable_sg(&fw->mem.sgt, sgl, i) {
+ struct page *page = vmalloc_to_page(data);
+
+ if (!page) {
+ ret = -EFAULT;
+ break;
+ }
+
+ sg_set_page(sgl, page, PAGE_SIZE, 0);
+ data += PAGE_SIZE;
+ }
+
+ if (ret == 0) {
+ ret = dma_map_sgtable(fw->device->dev, &fw->mem.sgt,
+ DMA_TO_DEVICE, 0);
+ }
+
+ if (ret)
+ sg_free_table(&fw->mem.sgt);
+ }
+
+ if (ret) {
+ vfree(fw->img);
+ fw->img = NULL;
+ }
+ }
+ break;
  default:
  WARN_ON(1);
  return -EINVAL;