[PATCH v2 4/5] nouveau/svm: use the new migration invalidation

From: Ralph Campbell <rcampbell@nvidia.com>
To: <linux-rdma@vger.kernel.org>, <linux-mm@kvack.org>,
	<nouveau@lists.freedesktop.org>, <kvm-ppc@vger.kernel.org>,
	<linux-kselftest@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Cc: Jerome Glisse <jglisse@redhat.com>,
	John Hubbard <jhubbard@nvidia.com>,
	Christoph Hellwig <hch@lst.de>,
	Jason Gunthorpe <jgg@mellanox.com>,
	"Andrew Morton" <akpm@linux-foundation.org>,
	Shuah Khan <shuah@kernel.org>, "Ben Skeggs" <bskeggs@redhat.com>,
	Bharata B Rao <bharata@linux.ibm.com>,
	"Ralph Campbell" <rcampbell@nvidia.com>
Subject: [PATCH v2 4/5] nouveau/svm: use the new migration invalidation
Date: Mon, 13 Jul 2020 10:21:48 -0700	[thread overview]
Message-ID: <20200713172149.2310-5-rcampbell@nvidia.com> (raw)
In-Reply-To: <20200713172149.2310-1-rcampbell@nvidia.com>

Use the new MMU_NOTIFY_MIGRATE event to skip GPU MMU invalidations of
device private memory and handle the invalidation in the driver as part
of migrating device private memory.

Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
---
 drivers/gpu/drm/nouveau/nouveau_dmem.c | 11 ++++++++---
 drivers/gpu/drm/nouveau/nouveau_svm.c  | 10 +++++++++-
 drivers/gpu/drm/nouveau/nouveau_svm.h  |  1 +
 3 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_dmem.c b/drivers/gpu/drm/nouveau/nouveau_dmem.c
index e5c83b8ee82e..8f2683ebd8c0 100644
--- a/drivers/gpu/drm/nouveau/nouveau_dmem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_dmem.c
@@ -154,6 +154,8 @@ static vm_fault_t nouveau_dmem_fault_copy_one(struct nouveau_drm *drm,
 	if (dma_mapping_error(dev, *dma_addr))
 		goto error_free_page;
 
+	nouveau_svmm_invalidate(spage->zone_device_data, 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;
@@ -531,7 +533,8 @@ 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, u64 *pfn)
+		struct nouveau_svmm *svmm, unsigned long src,
+		dma_addr_t *dma_addr, u64 *pfn)
 {
 	struct device *dev = drm->dev->dev;
 	struct page *dpage, *spage;
@@ -561,6 +564,7 @@ static unsigned long nouveau_dmem_migrate_copy_one(struct nouveau_drm *drm,
 			goto out_free_page;
 	}
 
+	dpage->zone_device_data = svmm;
 	*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)
@@ -584,8 +588,8 @@ static void nouveau_dmem_migrate_chunk(struct nouveau_drm *drm,
 	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, pfns + i);
+		args->dst[i] = nouveau_dmem_migrate_copy_one(drm, svmm,
+				args->src[i], dma_addrs + nr_dma, pfns + i);
 		if (!dma_mapping_error(drm->dev->dev, dma_addrs[nr_dma]))
 			nr_dma++;
 		addr += PAGE_SIZE;
@@ -616,6 +620,7 @@ nouveau_dmem_migrate_vma(struct nouveau_drm *drm,
 	struct migrate_vma args = {
 		.vma		= vma,
 		.start		= start,
+		.src_owner	= drm->dev,
 		.dir		= MIGRATE_VMA_FROM_SYSTEM,
 	};
 	unsigned long i;
diff --git a/drivers/gpu/drm/nouveau/nouveau_svm.c b/drivers/gpu/drm/nouveau/nouveau_svm.c
index c5f8ca6fb2e3..2ba7a8a2348c 100644
--- a/drivers/gpu/drm/nouveau/nouveau_svm.c
+++ b/drivers/gpu/drm/nouveau/nouveau_svm.c
@@ -246,7 +246,7 @@ nouveau_svmm_join(struct nouveau_svmm *svmm, u64 inst)
 }
 
 /* Invalidate SVMM address-range on GPU. */
-static void
+void
 nouveau_svmm_invalidate(struct nouveau_svmm *svmm, u64 start, u64 limit)
 {
 	if (limit > start) {
@@ -279,6 +279,14 @@ nouveau_svmm_invalidate_range_start(struct mmu_notifier *mn,
 	if (unlikely(!svmm->vmm))
 		goto out;
 
+	/*
+	 * Ignore invalidation callbacks for device private pages since
+	 * the invalidation is handled as part of the migration process.
+	 */
+	if (update->event == MMU_NOTIFY_MIGRATE &&
+	    update->migrate_pgmap_owner == svmm->vmm->cli->drm->dev)
+		goto out;
+
 	if (limit > svmm->unmanaged.start && start < svmm->unmanaged.limit) {
 		if (start < svmm->unmanaged.start) {
 			nouveau_svmm_invalidate(svmm, start,
diff --git a/drivers/gpu/drm/nouveau/nouveau_svm.h b/drivers/gpu/drm/nouveau/nouveau_svm.h
index f0fcd1b72e8b..bb2d56e50e0c 100644
--- a/drivers/gpu/drm/nouveau/nouveau_svm.h
+++ b/drivers/gpu/drm/nouveau/nouveau_svm.h
@@ -19,6 +19,7 @@ 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 *);
 
+void nouveau_svmm_invalidate(struct nouveau_svmm *svmm, u64 start, u64 limit);
 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,
-- 
2.20.1

