[PATCH 7/9] nouveau: simplify nouveau_dmem_migrate_vma

From: Christoph Hellwig
Date: Thu Aug 08 2019 - 11:34:41 EST


Factor the main copy page to vram routine out into a helper that acts
on a single page and which doesn't require the nouveau_dmem_migrate
structure for argument passing. As an added benefit the new version
only allocates the dma address array once and reuses it for each
subsequent chunk of work.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Ralph Campbell <rcampbell@xxxxxxxxxx>
---
drivers/gpu/drm/nouveau/nouveau_dmem.c | 184 ++++++++-----------------
1 file changed, 55 insertions(+), 129 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_dmem.c b/drivers/gpu/drm/nouveau/nouveau_dmem.c
index 473195762974..e20432a58ddb 100644
--- a/drivers/gpu/drm/nouveau/nouveau_dmem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_dmem.c
@@ -44,8 +44,6 @@
#define DMEM_CHUNK_SIZE (2UL << 20)
#define DMEM_CHUNK_NPAGES (DMEM_CHUNK_SIZE >> PAGE_SHIFT)

-struct nouveau_migrate;
-
enum nouveau_aper {
NOUVEAU_APER_VIRT,
NOUVEAU_APER_VRAM,
@@ -86,15 +84,6 @@ static inline struct nouveau_dmem *page_to_dmem(struct page *page)
return container_of(page->pgmap, struct nouveau_dmem, pagemap);
}

-struct nouveau_migrate {
- struct vm_area_struct *vma;
- struct nouveau_drm *drm;
- struct nouveau_fence *fence;
- unsigned long npages;
- dma_addr_t *dma;
- unsigned long dma_nr;
-};
-
static unsigned long nouveau_dmem_page_addr(struct page *page)
{
struct nouveau_dmem_chunk *chunk = page->zone_device_data;
@@ -570,131 +559,66 @@ nouveau_dmem_init(struct nouveau_drm *drm)
drm->dmem = NULL;
}

-static void
-nouveau_dmem_migrate_alloc_and_copy(struct vm_area_struct *vma,
- const unsigned long *src_pfns,
- unsigned long *dst_pfns,
- unsigned long start,
- unsigned long end,
- struct nouveau_migrate *migrate)
+static unsigned long nouveau_dmem_migrate_copy_one(struct nouveau_drm *drm,
+ unsigned long src, dma_addr_t *dma_addr)
{
- struct nouveau_drm *drm = migrate->drm;
struct device *dev = drm->dev->dev;
- unsigned long addr, i, npages = 0;
- nouveau_migrate_copy_t copy;
- int ret;
-
- /* First allocate new memory */
- for (addr = start, i = 0; addr < end; addr += PAGE_SIZE, i++) {
- struct page *dpage, *spage;
-
- dst_pfns[i] = 0;
- spage = migrate_pfn_to_page(src_pfns[i]);
- if (!spage || !(src_pfns[i] & MIGRATE_PFN_MIGRATE))
- continue;
-
- dpage = nouveau_dmem_page_alloc_locked(drm);
- if (!dpage)
- continue;
-
- dst_pfns[i] = migrate_pfn(page_to_pfn(dpage)) |
- MIGRATE_PFN_LOCKED |
- MIGRATE_PFN_DEVICE;
- npages++;
- }
-
- if (!npages)
- return;
-
- /* Allocate storage for DMA addresses, so we can unmap later. */
- migrate->dma = kmalloc(sizeof(*migrate->dma) * npages, GFP_KERNEL);
- if (!migrate->dma)
- goto error;
- migrate->dma_nr = 0;
-
- /* Copy things over */
- copy = drm->dmem->migrate.copy_func;
- for (addr = start, i = 0; addr < end; addr += PAGE_SIZE, i++) {
- struct page *spage, *dpage;
-
- dpage = migrate_pfn_to_page(dst_pfns[i]);
- if (!dpage || dst_pfns[i] == MIGRATE_PFN_ERROR)
- continue;
-
- spage = migrate_pfn_to_page(src_pfns[i]);
- if (!spage || !(src_pfns[i] & MIGRATE_PFN_MIGRATE)) {
- nouveau_dmem_page_free_locked(drm, dpage);
- dst_pfns[i] = 0;
- continue;
- }
-
- migrate->dma[migrate->dma_nr] =
- dma_map_page_attrs(dev, spage, 0, PAGE_SIZE,
- PCI_DMA_BIDIRECTIONAL,
- DMA_ATTR_SKIP_CPU_SYNC);
- if (dma_mapping_error(dev, migrate->dma[migrate->dma_nr])) {
- nouveau_dmem_page_free_locked(drm, dpage);
- dst_pfns[i] = 0;
- continue;
- }
-
- ret = copy(drm, 1, NOUVEAU_APER_VRAM,
- nouveau_dmem_page_addr(dpage),
- NOUVEAU_APER_HOST,
- migrate->dma[migrate->dma_nr++]);
- if (ret) {
- nouveau_dmem_page_free_locked(drm, dpage);
- dst_pfns[i] = 0;
- continue;
- }
- }
+ struct page *dpage, *spage;

- nouveau_fence_new(drm->dmem->migrate.chan, false, &migrate->fence);
+ spage = migrate_pfn_to_page(src);
+ if (!spage || !(src & MIGRATE_PFN_MIGRATE))
+ goto out;

- return;
+ dpage = nouveau_dmem_page_alloc_locked(drm);
+ if (!dpage)
+ return 0;

-error:
- for (addr = start, i = 0; addr < end; addr += PAGE_SIZE, ++i) {
- struct page *page;
+ *dma_addr = dma_map_page(dev, spage, 0, PAGE_SIZE, DMA_BIDIRECTIONAL);
+ if (dma_mapping_error(dev, *dma_addr))
+ goto out_free_page;

- if (!dst_pfns[i] || dst_pfns[i] == MIGRATE_PFN_ERROR)
- continue;
+ if (drm->dmem->migrate.copy_func(drm, 1, NOUVEAU_APER_VRAM,
+ nouveau_dmem_page_addr(dpage), NOUVEAU_APER_HOST,
+ *dma_addr))
+ goto out_dma_unmap;

- page = migrate_pfn_to_page(dst_pfns[i]);
- dst_pfns[i] = MIGRATE_PFN_ERROR;
- if (page == NULL)
- continue;
+ return migrate_pfn(page_to_pfn(dpage)) |
+ MIGRATE_PFN_LOCKED | MIGRATE_PFN_DEVICE;

- __free_page(page);
- }
+out_dma_unmap:
+ dma_unmap_page(dev, *dma_addr, PAGE_SIZE, DMA_BIDIRECTIONAL);
+out_free_page:
+ nouveau_dmem_page_free_locked(drm, dpage);
+out:
+ return 0;
}

-static void
-nouveau_dmem_migrate_finalize_and_map(struct nouveau_migrate *migrate)
+static void nouveau_dmem_migrate_chunk(struct nouveau_drm *drm,
+ struct migrate_vma *args, dma_addr_t *dma_addrs)
{
- struct nouveau_drm *drm = migrate->drm;
+ 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]);
+ if (args->dst[i])
+ nr_dma++;
+ addr += PAGE_SIZE;
+ }

- nouveau_dmem_fence_done(&migrate->fence);
+ nouveau_fence_new(drm->dmem->migrate.chan, false, &fence);
+ migrate_vma_pages(args);
+ nouveau_dmem_fence_done(&fence);

- while (migrate->dma_nr--) {
- dma_unmap_page(drm->dev->dev, migrate->dma[migrate->dma_nr],
- PAGE_SIZE, PCI_DMA_BIDIRECTIONAL);
+ while (nr_dma--) {
+ dma_unmap_page(drm->dev->dev, dma_addrs[nr_dma], PAGE_SIZE,
+ DMA_BIDIRECTIONAL);
}
- kfree(migrate->dma);
-
/*
- * FIXME optimization: update GPU page table to point to newly
- * migrated memory.
+ * FIXME optimization: update GPU page table to point to newly migrated
+ * memory.
*/
-}
-
-static void nouveau_dmem_migrate_chunk(struct migrate_vma *args,
- struct nouveau_migrate *migrate)
-{
- nouveau_dmem_migrate_alloc_and_copy(args->vma, args->src, args->dst,
- args->start, args->end, migrate);
- migrate_vma_pages(args);
- nouveau_dmem_migrate_finalize_and_map(migrate);
migrate_vma_finalize(args);
}

@@ -706,38 +630,40 @@ 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;
struct migrate_vma args = {
.vma = vma,
.start = start,
};
- struct nouveau_migrate migrate = {
- .drm = drm,
- .vma = vma,
- .npages = npages,
- };
unsigned long c, i;
int ret = -ENOMEM;

- args.src = kzalloc(sizeof(long) * max, GFP_KERNEL);
+ args.src = kcalloc(max, sizeof(args.src), GFP_KERNEL);
if (!args.src)
goto out;
- args.dst = kzalloc(sizeof(long) * max, GFP_KERNEL);
+ args.dst = kcalloc(max, sizeof(args.dst), GFP_KERNEL);
if (!args.dst)
goto out_free_src;

+ dma_addrs = kmalloc_array(max, sizeof(*dma_addrs), GFP_KERNEL);
+ 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);
ret = migrate_vma_setup(&args);
if (ret)
- goto out_free_dst;
+ goto out_free_dma;

if (args.cpages)
- nouveau_dmem_migrate_chunk(&args, &migrate);
+ nouveau_dmem_migrate_chunk(drm, &args, dma_addrs);
args.start = args.end;
}

ret = 0;
+out_free_dma:
+ kfree(dma_addrs);
out_free_dst:
kfree(args.dst);
out_free_src:
--
2.20.1