When memory is migrated to the GPU, it is likely to be accessed by GPU code soon afterwards. Instead of waiting for a GPU fault, map the migrated memory into the GPU page tables with the same access permissions as the source CPU page table entries. This preserves copy on write semantics.
Signed-off-by: Ralph Campbell rcampbell@nvidia.com Cc: Christoph Hellwig hch@lst.de Cc: Jason Gunthorpe jgg@mellanox.com Cc: "Jérôme Glisse" jglisse@redhat.com Cc: Ben Skeggs bskeggs@redhat.com --- drivers/gpu/drm/nouveau/nouveau_dmem.c | 46 +++++++++++++------- drivers/gpu/drm/nouveau/nouveau_dmem.h | 2 + drivers/gpu/drm/nouveau/nouveau_svm.c | 59 +++++++++++++++++++++++++- drivers/gpu/drm/nouveau/nouveau_svm.h | 5 +++ 4 files changed, 95 insertions(+), 17 deletions(-)
diff --git a/drivers/gpu/drm/nouveau/nouveau_dmem.c b/drivers/gpu/drm/nouveau/nouveau_dmem.c index 0ad5d87b5a8e..981c05a2a6ca 100644 --- a/drivers/gpu/drm/nouveau/nouveau_dmem.c +++ b/drivers/gpu/drm/nouveau/nouveau_dmem.c @@ -25,11 +25,13 @@ #include "nouveau_dma.h" #include "nouveau_mem.h" #include "nouveau_bo.h" +#include "nouveau_svm.h"
#include <nvif/class.h> #include <nvif/object.h> #include <nvif/if500b.h> #include <nvif/if900b.h> +#include <nvif/if000c.h>
#include <linux/sched/mm.h> #include <linux/hmm.h> @@ -558,10 +560,11 @@ nouveau_dmem_init(struct nouveau_drm *drm) }
static unsigned long nouveau_dmem_migrate_copy_one(struct nouveau_drm *drm, - unsigned long src, dma_addr_t *dma_addr) + unsigned long src, dma_addr_t *dma_addr, u64 *pfn) { struct device *dev = drm->dev->dev; struct page *dpage, *spage; + unsigned long paddr;
spage = migrate_pfn_to_page(src); if (!spage || !(src & MIGRATE_PFN_MIGRATE)) @@ -569,17 +572,21 @@ static unsigned long nouveau_dmem_migrate_copy_one(struct nouveau_drm *drm,
dpage = nouveau_dmem_page_alloc_locked(drm); if (!dpage) - return 0; + goto out;
*dma_addr = dma_map_page(dev, spage, 0, PAGE_SIZE, DMA_BIDIRECTIONAL); if (dma_mapping_error(dev, *dma_addr)) goto out_free_page;
+ paddr = nouveau_dmem_page_addr(dpage); if (drm->dmem->migrate.copy_func(drm, 1, NOUVEAU_APER_VRAM, - nouveau_dmem_page_addr(dpage), NOUVEAU_APER_HOST, - *dma_addr)) + paddr, NOUVEAU_APER_HOST, *dma_addr)) goto out_dma_unmap;
+ *pfn = NVIF_VMM_PFNMAP_V0_V | NVIF_VMM_PFNMAP_V0_VRAM | + ((paddr >> PAGE_SHIFT) << NVIF_VMM_PFNMAP_V0_ADDR_SHIFT); + if (src & MIGRATE_PFN_WRITE) + *pfn |= NVIF_VMM_PFNMAP_V0_W; return migrate_pfn(page_to_pfn(dpage)) | MIGRATE_PFN_LOCKED;
out_dma_unmap: @@ -587,18 +594,20 @@ static unsigned long nouveau_dmem_migrate_copy_one(struct nouveau_drm *drm, out_free_page: nouveau_dmem_page_free_locked(drm, dpage); out: + *pfn = NVIF_VMM_PFNMAP_V0_NONE; return 0; }
static void nouveau_dmem_migrate_chunk(struct nouveau_drm *drm, - struct migrate_vma *args, dma_addr_t *dma_addrs) + struct nouveau_svmm *svmm, struct migrate_vma *args, + dma_addr_t *dma_addrs, u64 *pfns) { struct nouveau_fence *fence; unsigned long addr = args->start, nr_dma = 0, i;
for (i = 0; addr < args->end; i++) { args->dst[i] = nouveau_dmem_migrate_copy_one(drm, args->src[i], - dma_addrs + nr_dma); + dma_addrs + nr_dma, pfns + i); if (args->dst[i]) nr_dma++; addr += PAGE_SIZE; @@ -607,20 +616,18 @@ static void nouveau_dmem_migrate_chunk(struct nouveau_drm *drm, nouveau_fence_new(drm->dmem->migrate.chan, false, &fence); migrate_vma_pages(args); nouveau_dmem_fence_done(&fence); + nouveau_pfns_map(svmm, args->vma->vm_mm, args->start, pfns, i);
while (nr_dma--) { dma_unmap_page(drm->dev->dev, dma_addrs[nr_dma], PAGE_SIZE, DMA_BIDIRECTIONAL); } - /* - * FIXME optimization: update GPU page table to point to newly migrated - * memory. - */ migrate_vma_finalize(args); }
int nouveau_dmem_migrate_vma(struct nouveau_drm *drm, + struct nouveau_svmm *svmm, struct vm_area_struct *vma, unsigned long start, unsigned long end) @@ -632,7 +639,8 @@ nouveau_dmem_migrate_vma(struct nouveau_drm *drm, .vma = vma, .start = start, }; - unsigned long c, i; + unsigned long i; + u64 *pfns; int ret = -ENOMEM;
args.src = kcalloc(max, sizeof(*args.src), GFP_KERNEL); @@ -646,19 +654,25 @@ nouveau_dmem_migrate_vma(struct nouveau_drm *drm, if (!dma_addrs) goto out_free_dst;
- for (i = 0; i < npages; i += c) { - c = min(SG_MAX_SINGLE_ALLOC, npages); - args.end = start + (c << PAGE_SHIFT); + pfns = nouveau_pfns_alloc(max); + if (!pfns) + goto out_free_dma; + + for (i = 0; i < npages; i += max) { + args.end = start + (max << PAGE_SHIFT); ret = migrate_vma_setup(&args); if (ret) - goto out_free_dma; + goto out_free_pfns;
if (args.cpages) - nouveau_dmem_migrate_chunk(drm, &args, dma_addrs); + nouveau_dmem_migrate_chunk(drm, svmm, &args, dma_addrs, + pfns); args.start = args.end; }
ret = 0; +out_free_pfns: + nouveau_pfns_free(pfns); out_free_dma: kfree(dma_addrs); out_free_dst: diff --git a/drivers/gpu/drm/nouveau/nouveau_dmem.h b/drivers/gpu/drm/nouveau/nouveau_dmem.h index 92394be5d649..3e03d9629a38 100644 --- a/drivers/gpu/drm/nouveau/nouveau_dmem.h +++ b/drivers/gpu/drm/nouveau/nouveau_dmem.h @@ -25,6 +25,7 @@ struct drm_device; struct drm_file; struct nouveau_drm; +struct nouveau_svmm; struct hmm_range;
#if IS_ENABLED(CONFIG_DRM_NOUVEAU_SVM) @@ -34,6 +35,7 @@ void nouveau_dmem_suspend(struct nouveau_drm *); void nouveau_dmem_resume(struct nouveau_drm *);
int nouveau_dmem_migrate_vma(struct nouveau_drm *drm, + struct nouveau_svmm *svmm, struct vm_area_struct *vma, unsigned long start, unsigned long end); diff --git a/drivers/gpu/drm/nouveau/nouveau_svm.c b/drivers/gpu/drm/nouveau/nouveau_svm.c index 8dfa5cb74826..d33ae94c28ba 100644 --- a/drivers/gpu/drm/nouveau/nouveau_svm.c +++ b/drivers/gpu/drm/nouveau/nouveau_svm.c @@ -70,6 +70,12 @@ struct nouveau_svm { #define SVM_DBG(s,f,a...) NV_DEBUG((s)->drm, "svm: "f"\n", ##a) #define SVM_ERR(s,f,a...) NV_WARN((s)->drm, "svm: "f"\n", ##a)
+struct nouveau_pfnmap_args { + struct nvif_ioctl_v0 i; + struct nvif_ioctl_mthd_v0 m; + struct nvif_vmm_pfnmap_v0 p; +}; + struct nouveau_ivmm { struct nouveau_svmm *svmm; u64 inst; @@ -187,7 +193,8 @@ nouveau_svmm_bind(struct drm_device *dev, void *data, addr = max(addr, vma->vm_start); next = min(vma->vm_end, end); /* This is a best effort so we ignore errors */ - nouveau_dmem_migrate_vma(cli->drm, vma, addr, next); + nouveau_dmem_migrate_vma(cli->drm, cli->svm.svmm, vma, addr, + next); addr = next; }
@@ -785,6 +792,56 @@ nouveau_svm_fault(struct nvif_notify *notify) return NVIF_NOTIFY_KEEP; }
+static struct nouveau_pfnmap_args * +nouveau_pfns_to_args(void *pfns) +{ + return container_of(pfns, struct nouveau_pfnmap_args, p.phys); +} + +u64 * +nouveau_pfns_alloc(unsigned long npages) +{ + struct nouveau_pfnmap_args *args; + + args = kzalloc(struct_size(args, p.phys, npages), GFP_KERNEL); + if (!args) + return NULL; + + args->i.type = NVIF_IOCTL_V0_MTHD; + args->m.method = NVIF_VMM_V0_PFNMAP; + args->p.page = PAGE_SHIFT; + + return args->p.phys; +} + +void +nouveau_pfns_free(u64 *pfns) +{ + struct nouveau_pfnmap_args *args = nouveau_pfns_to_args(pfns); + + kfree(args); +} + +void +nouveau_pfns_map(struct nouveau_svmm *svmm, struct mm_struct *mm, + unsigned long addr, u64 *pfns, unsigned long npages) +{ + struct nouveau_pfnmap_args *args = nouveau_pfns_to_args(pfns); + int ret; + + args->p.addr = addr; + args->p.size = npages << PAGE_SHIFT; + + mutex_lock(&svmm->mutex); + + svmm->vmm->vmm.object.client->super = true; + ret = nvif_object_ioctl(&svmm->vmm->vmm.object, args, sizeof(*args) + + npages * sizeof(args->p.phys[0]), NULL); + svmm->vmm->vmm.object.client->super = false; + + mutex_unlock(&svmm->mutex); +} + static void nouveau_svm_fault_buffer_fini(struct nouveau_svm *svm, int id) { diff --git a/drivers/gpu/drm/nouveau/nouveau_svm.h b/drivers/gpu/drm/nouveau/nouveau_svm.h index e839d8189461..f0fcd1b72e8b 100644 --- a/drivers/gpu/drm/nouveau/nouveau_svm.h +++ b/drivers/gpu/drm/nouveau/nouveau_svm.h @@ -18,6 +18,11 @@ void nouveau_svmm_fini(struct nouveau_svmm **); int nouveau_svmm_join(struct nouveau_svmm *, u64 inst); void nouveau_svmm_part(struct nouveau_svmm *, u64 inst); int nouveau_svmm_bind(struct drm_device *, void *, struct drm_file *); + +u64 *nouveau_pfns_alloc(unsigned long npages); +void nouveau_pfns_free(u64 *pfns); +void nouveau_pfns_map(struct nouveau_svmm *svmm, struct mm_struct *mm, + unsigned long addr, u64 *pfns, unsigned long npages); #else /* IS_ENABLED(CONFIG_DRM_NOUVEAU_SVM) */ static inline void nouveau_svm_init(struct nouveau_drm *drm) {} static inline void nouveau_svm_fini(struct nouveau_drm *drm) {}