[PATCH 5/7] nouveau/dmem: Refactor nouveau_dmem_fault_copy_one()

Alistair Popple
2022-09-26T06:05:13Z

nouveau_dmem_fault_copy_one() is used during handling of CPU faults via
the migrate_to_ram() callback and is used to copy data from GPU to CPU
memory. It is currently specific to fault handling, however a future
patch implementing eviction of data during teardown needs similar
functionality.

Refactor out the core functionality so that it is not specific to fault
handling.

Signed-off-by: Alistair Popple <apopple@nvidia.com>
---
drivers/gpu/drm/nouveau/nouveau_dmem.c | 59 +++++++++++++--------------
1 file changed, 29 insertions(+), 30 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_dmem.c b/drivers/gpu/drm/nouveau/nouveau_dmem.c
index f9234ed..66ebbd4 100644
--- a/drivers/gpu/drm/nouveau/nouveau_dmem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_dmem.c
@@ -139,44 +139,25 @@ static void nouveau_dmem_fence_done(struct nouveau_fence **fence)
}
}

-static vm_fault_t nouveau_dmem_fault_copy_one(struct nouveau_drm *drm,
- struct vm_fault *vmf, struct migrate_vma *args,
- dma_addr_t *dma_addr)
+static int nouveau_dmem_copy_one(struct nouveau_drm *drm, struct page *spage,
+ struct page *dpage, dma_addr_t *dma_addr)
{
struct device *dev = drm->dev->dev;
- struct page *dpage, *spage;
- struct nouveau_svmm *svmm;
-
- spage = migrate_pfn_to_page(args->src[0]);
- if (!spage || !(args->src[0] & MIGRATE_PFN_MIGRATE))
- return 0;

- dpage = alloc_page_vma(GFP_HIGHUSER, vmf->vma, vmf->address);
- if (!dpage)
- return VM_FAULT_SIGBUS;
lock_page(dpage);

*dma_addr = dma_map_page(dev, dpage, 0, PAGE_SIZE, DMA_BIDIRECTIONAL);
if (dma_mapping_error(dev, *dma_addr))
- goto error_free_page;
+ return -EIO;

- svmm = spage->zone_device_data;
- mutex_lock(&svmm->mutex);
- nouveau_svmm_invalidate(svmm, args->start, args->end);
if (drm->dmem->migrate.copy_func(drm, 1, NOUVEAU_APER_HOST, *dma_addr,
- NOUVEAU_APER_VRAM, nouveau_dmem_page_addr(spage)))
- goto error_dma_unmap;
- mutex_unlock(&svmm->mutex);
+ NOUVEAU_APER_VRAM,
+ nouveau_dmem_page_addr(spage))) {
+ dma_unmap_page(dev, *dma_addr, PAGE_SIZE, DMA_BIDIRECTIONAL);
+ return -EIO;
+ }

- args->dst[0] = migrate_pfn(page_to_pfn(dpage));
return 0;
-
-error_dma_unmap:
- mutex_unlock(&svmm->mutex);
- dma_unmap_page(dev, *dma_addr, PAGE_SIZE, DMA_BIDIRECTIONAL);
-error_free_page:
- __free_page(dpage);
- return VM_FAULT_SIGBUS;
}

static vm_fault_t nouveau_dmem_migrate_to_ram(struct vm_fault *vmf)
@@ -184,9 +165,11 @@ static vm_fault_t nouveau_dmem_migrate_to_ram(struct vm_fault *vmf)
struct nouveau_drm *drm = page_to_drm(vmf->page);
struct nouveau_dmem *dmem = drm->dmem;
struct nouveau_fence *fence;
+ struct nouveau_svmm *svmm;
+ struct page *spage, *dpage;
unsigned long src = 0, dst = 0;
dma_addr_t dma_addr = 0;
- vm_fault_t ret;
+ vm_fault_t ret = 0;
struct migrate_vma args = {
.vma = vmf->vma,
.start = vmf->address,
@@ -207,9 +190,25 @@ static vm_fault_t nouveau_dmem_migrate_to_ram(struct vm_fault *vmf)
if (!args.cpages)
return 0;

- ret = nouveau_dmem_fault_copy_one(drm, vmf, &args, &dma_addr);
- if (ret || dst == 0)
+ spage = migrate_pfn_to_page(src);
+ if (!spage || !(src & MIGRATE_PFN_MIGRATE))
+ goto done;
+
+ dpage = alloc_page_vma(GFP_HIGHUSER, vmf->vma, vmf->address);
+ if (!dpage)
+ goto done;
+
+ dst = migrate_pfn(page_to_pfn(dpage));
+
+ svmm = spage->zone_device_data;
+ mutex_lock(&svmm->mutex);
+ nouveau_svmm_invalidate(svmm, args.start, args.end);
+ ret = nouveau_dmem_copy_one(drm, spage, dpage, &dma_addr);
+ mutex_unlock(&svmm->mutex);
+ if (ret) {
+ ret = VM_FAULT_SIGBUS;
goto done;
+ }

nouveau_fence_new(dmem->migrate.chan, false, &fence);
migrate_vma_pages(&args);
--
git-series 0.9.1