[PATCH 18/25] nouveau: use devm_memremap_pages directly

[Christoph Hellwig]

Just use devm_memremap_pages instead of hmm_devmem_add pages to allow
killing that wrapper which doesn't provide a whole lot of benefits.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
 drivers/gpu/drm/nouveau/nouveau_dmem.c | 82 ++++++++++++--------------
 1 file changed, 38 insertions(+), 44 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_dmem.c b/drivers/gpu/drm/nouveau/nouveau_dmem.c
index a50f6fd2fe24..0fb7a44b8bc4 100644
--- a/drivers/gpu/drm/nouveau/nouveau_dmem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_dmem.c
@@ -72,7 +72,8 @@ struct nouveau_dmem_migrate {
 };
 
 struct nouveau_dmem {
-	struct hmm_devmem *devmem;
+	struct nouveau_drm *drm;
+	struct dev_pagemap pagemap;
 	struct nouveau_dmem_migrate migrate;
 	struct list_head chunk_free;
 	struct list_head chunk_full;
@@ -80,6 +81,11 @@ struct nouveau_dmem {
 	struct mutex mutex;
 };
 
+static inline struct nouveau_dmem *page_to_dmem(struct page *page)
+{
+	return container_of(page->pgmap, struct nouveau_dmem, pagemap);
+}
+
 struct nouveau_dmem_fault {
 	struct nouveau_drm *drm;
 	struct nouveau_fence *fence;
@@ -96,8 +102,7 @@ struct nouveau_migrate {
 	unsigned long dma_nr;
 };
 
-static void
-nouveau_dmem_free(struct hmm_devmem *devmem, struct page *page)
+static void nouveau_dmem_page_free(struct page *page)
 {
 	struct nouveau_dmem_chunk *chunk;
 	unsigned long idx;
@@ -260,29 +265,21 @@ static const struct migrate_vma_ops nouveau_dmem_fault_migrate_ops = {
 	.finalize_and_map	= nouveau_dmem_fault_finalize_and_map,
 };
 
-static vm_fault_t
-nouveau_dmem_fault(struct hmm_devmem *devmem,
-		   struct vm_area_struct *vma,
-		   unsigned long addr,
-		   const struct page *page,
-		   unsigned int flags,
-		   pmd_t *pmdp)
+static vm_fault_t nouveau_dmem_migrate_to_ram(struct vm_fault *vmf)
 {
-	struct drm_device *drm_dev = dev_get_drvdata(devmem->device);
+	struct nouveau_dmem *dmem = page_to_dmem(vmf->page);
 	unsigned long src[1] = {0}, dst[1] = {0};
-	struct nouveau_dmem_fault fault = {0};
+	struct nouveau_dmem_fault fault = { .drm = dmem->drm };
 	int ret;
 
-
-
 	/*
 	 * FIXME what we really want is to find some heuristic to migrate more
 	 * than just one page on CPU fault. When such fault happens it is very
 	 * likely that more surrounding page will CPU fault too.
 	 */
-	fault.drm = nouveau_drm(drm_dev);
-	ret = migrate_vma(&nouveau_dmem_fault_migrate_ops, vma, addr,
-			  addr + PAGE_SIZE, src, dst, &fault);
+	ret = migrate_vma(&nouveau_dmem_fault_migrate_ops, vmf->vma,
+			vmf->address, vmf->address + PAGE_SIZE,
+			src, dst, &fault);
 	if (ret)
 		return VM_FAULT_SIGBUS;
 
@@ -292,10 +289,9 @@ nouveau_dmem_fault(struct hmm_devmem *devmem,
 	return 0;
 }
 
-static const struct hmm_devmem_ops
-nouveau_dmem_devmem_ops = {
-	.free = nouveau_dmem_free,
-	.fault = nouveau_dmem_fault,
+static const struct dev_pagemap_ops nouveau_dmem_pagemap_ops = {
+	.page_free		= nouveau_dmem_page_free,
+	.migrate_to_ram		= nouveau_dmem_migrate_to_ram,
 };
 
 static int
@@ -581,7 +577,8 @@ void
 nouveau_dmem_init(struct nouveau_drm *drm)
 {
 	struct device *device = drm->dev->dev;
-	unsigned long i, size;
+	struct resource *res;
+	unsigned long i, size, pfn_first;
 	int ret;
 
 	/* This only make sense on PASCAL or newer */
@@ -591,6 +588,7 @@ nouveau_dmem_init(struct nouveau_drm *drm)
 	if (!(drm->dmem = kzalloc(sizeof(*drm->dmem), GFP_KERNEL)))
 		return;
 
+	drm->dmem->drm = drm;
 	mutex_init(&drm->dmem->mutex);
 	INIT_LIST_HEAD(&drm->dmem->chunk_free);
 	INIT_LIST_HEAD(&drm->dmem->chunk_full);
@@ -600,11 +598,8 @@ nouveau_dmem_init(struct nouveau_drm *drm)
 
 	/* Initialize migration dma helpers before registering memory */
 	ret = nouveau_dmem_migrate_init(drm);
-	if (ret) {
-		kfree(drm->dmem);
-		drm->dmem = NULL;
-		return;
-	}
+	if (ret)
+		goto out_free;
 
 	/*
 	 * FIXME we need some kind of policy to decide how much VRAM we
@@ -612,14 +607,16 @@ nouveau_dmem_init(struct nouveau_drm *drm)
 	 * and latter if we want to do thing like over commit then we
 	 * could revisit this.
 	 */
-	drm->dmem->devmem = hmm_devmem_add(&nouveau_dmem_devmem_ops,
-					   device, size);
-	if (IS_ERR(drm->dmem->devmem)) {
-		kfree(drm->dmem);
-		drm->dmem = NULL;
-		return;
-	}
-
+	res = devm_request_free_mem_region(device, &iomem_resource, size);
+	if (IS_ERR(res))
+		goto out_free;
+	drm->dmem->pagemap.type = MEMORY_DEVICE_PRIVATE;
+	drm->dmem->pagemap.res = *res;
+	drm->dmem->pagemap.ops = &nouveau_dmem_pagemap_ops;
+	if (IS_ERR(devm_memremap_pages(device, &drm->dmem->pagemap)))
+		goto out_free;
+
+	pfn_first = res->start >> PAGE_SHIFT;
 	for (i = 0; i < (size / DMEM_CHUNK_SIZE); ++i) {
 		struct nouveau_dmem_chunk *chunk;
 		struct page *page;
@@ -632,8 +629,7 @@ nouveau_dmem_init(struct nouveau_drm *drm)
 		}
 
 		chunk->drm = drm;
-		chunk->pfn_first = drm->dmem->devmem->pfn_first;
-		chunk->pfn_first += (i * DMEM_CHUNK_NPAGES);
+		chunk->pfn_first = pfn_first + (i * DMEM_CHUNK_NPAGES);
 		list_add_tail(&chunk->list, &drm->dmem->chunk_empty);
 
 		page = pfn_to_page(chunk->pfn_first);
@@ -643,6 +639,10 @@ nouveau_dmem_init(struct nouveau_drm *drm)
 	}
 
 	NV_INFO(drm, "DMEM: registered %ldMB of device memory\n", size >> 20);
+	return;
+out_free:
+	kfree(drm->dmem);
+	drm->dmem = NULL;
 }
 
 static void
@@ -833,13 +833,7 @@ nouveau_dmem_migrate_vma(struct nouveau_drm *drm,
 static inline bool
 nouveau_dmem_page(struct nouveau_drm *drm, struct page *page)
 {
-	if (!is_device_private_page(page))
-		return false;
-
-	if (drm->dmem->devmem != page->pgmap->data)
-		return false;
-
-	return true;
+	return is_device_private_page(page) && drm->dmem == page_to_dmem(page);
 }
 
 void
-- 
2.20.1