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 <rcampb...@nvidia.com> Cc: Christoph Hellwig <h...@lst.de> Cc: Jason Gunthorpe <j...@mellanox.com> Cc: "Jérôme Glisse" <jgli...@redhat.com> Cc: Ben Skeggs <bske...@redhat.com> --- This patch is based on top of Christoph Hellwig's 9 patch series https://lore.kernel.org/linux-mm/20190729234611.gc7...@redhat.com/T/#u "turn the hmm migrate_vma upside down" but without patch 9 "mm: remove the unused MIGRATE_PFN_WRITE" and adds a use for the flag. drivers/gpu/drm/nouveau/nouveau_dmem.c | 45 +++++++++----- drivers/gpu/drm/nouveau/nouveau_svm.c | 86 ++++++++++++++++++++++++++ drivers/gpu/drm/nouveau/nouveau_svm.h | 19 ++++++ 3 files changed, 133 insertions(+), 17 deletions(-) diff --git a/drivers/gpu/drm/nouveau/nouveau_dmem.c b/drivers/gpu/drm/nouveau/nouveau_dmem.c index ef9de82b0744..c83e6f118817 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> @@ -560,11 +562,12 @@ nouveau_dmem_init(struct nouveau_drm *drm) } static unsigned long nouveau_dmem_migrate_copy_one(struct nouveau_drm *drm, - struct vm_area_struct *vma, unsigned long addr, - unsigned long src, dma_addr_t *dma_addr) + struct vm_area_struct *vma, 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)) @@ -572,17 +575,21 @@ 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: @@ -590,18 +597,19 @@ 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 migrate_vma *args, - struct nouveau_drm *drm, dma_addr_t *dma_addrs) + struct nouveau_drm *drm, 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->vma, - addr, args->src[i], &dma_addrs[nr_dma]); + args->src[i], &dma_addrs[nr_dma], &pfns[i]); if (args->dst[i]) nr_dma++; addr += PAGE_SIZE; @@ -615,10 +623,6 @@ static void nouveau_dmem_migrate_chunk(struct migrate_vma *args, 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); } @@ -631,11 +635,12 @@ nouveau_dmem_migrate_vma(struct nouveau_drm *drm, unsigned long npages = (end - start) >> PAGE_SHIFT; unsigned long max = min(SG_MAX_SINGLE_ALLOC, npages); dma_addr_t *dma_addrs; + u64 *pfns; struct migrate_vma args = { .vma = vma, .start = start, }; - unsigned long c, i; + unsigned long i; int ret = -ENOMEM; args.src = kcalloc(max, sizeof(args.src), GFP_KERNEL); @@ -649,19 +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(&args, drm, dma_addrs); + nouveau_dmem_migrate_chunk(&args, drm, 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_svm.c b/drivers/gpu/drm/nouveau/nouveau_svm.c index a74530b5a523..3e6d7f226576 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; @@ -734,6 +740,86 @@ nouveau_svm_fault(struct nvif_notify *notify) return NVIF_NOTIFY_KEEP; } +static inline struct nouveau_pfnmap_args * +nouveau_pfns_to_args(void *pfns) +{ + struct nvif_vmm_pfnmap_v0 *p = + container_of(pfns, struct nvif_vmm_pfnmap_v0, phys); + + return container_of(p, struct nouveau_pfnmap_args, p); +} + +u64 * +nouveau_pfns_alloc(unsigned long npages) +{ + struct nouveau_pfnmap_args *args; + + args = kzalloc(sizeof(*args) + npages * sizeof(args->p.phys[0]), + 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); +} + +static struct nouveau_svmm * +nouveau_find_svmm(struct nouveau_svm *svm, struct mm_struct *mm) +{ + struct nouveau_ivmm *ivmm; + + list_for_each_entry(ivmm, &svm->inst, head) { + if (ivmm->svmm->mm == mm) + return ivmm->svmm; + } + return NULL; +} + +void +nouveau_pfns_map(struct nouveau_drm *drm, struct mm_struct *mm, + unsigned long addr, u64 *pfns, unsigned long npages) +{ + struct nouveau_svm *svm = drm->svm; + struct nouveau_svmm *svmm; + struct nouveau_pfnmap_args *args; + int ret; + + if (!svm) + return; + + mutex_lock(&svm->mutex); + svmm = nouveau_find_svmm(svm, mm); + if (!svmm) { + mutex_unlock(&svm->mutex); + return; + } + mutex_unlock(&svm->mutex); + + args = nouveau_pfns_to_args(pfns); + 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..c00c177e51ed 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_drm *drm, 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) {} @@ -44,5 +49,19 @@ static inline int nouveau_svmm_bind(struct drm_device *device, void *p, { return -ENOSYS; } + +u64 *nouveau_pfns_alloc(unsigned long npages) +{ + return NULL; +} + +void nouveau_pfns_free(u64 *pfns) +{ +} + +void nouveau_pfns_map(struct nouveau_drm *drm, struct mm_struct *mm, + unsigned long addr, u64 *pfns, unsigned long npages) +{ +} #endif /* IS_ENABLED(CONFIG_DRM_NOUVEAU_SVM) */ #endif -- 2.20.1 _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel
