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| author | Alistair Popple <apopple@nvidia.com> | 2021-06-30 18:54:35 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-07-01 11:06:04 -0700 |
| commit | 8f187163eb890d6d2a53f7efea2b6963fe9526e2 (patch) | |
| tree | 7f7483626a28203dc07713a313bd62a4a002abe3 /drivers/gpu/drm/nouveau/include/nvif | |
| parent | f81c69a2a144afefa277db4917a76bcaecfa2f2e (diff) | |
| download | linux-8f187163eb890d6d2a53f7efea2b6963fe9526e2.tar.gz linux-8f187163eb890d6d2a53f7efea2b6963fe9526e2.tar.bz2 linux-8f187163eb890d6d2a53f7efea2b6963fe9526e2.zip | |
nouveau/svm: implement atomic SVM access
Some NVIDIA GPUs do not support direct atomic access to system memory via
PCIe. Instead this must be emulated by granting the GPU exclusive access
to the memory. This is achieved by replacing CPU page table entries with
special swap entries that fault on userspace access.
The driver then grants the GPU permission to update the page undergoing
atomic access via the GPU page tables. When CPU access to the page is
required a CPU fault is raised which calls into the device driver via MMU
notifiers to revoke the atomic access. The original page table entries
are then restored allowing CPU access to proceed.
Link: https://lkml.kernel.org/r/20210616105937.23201-11-apopple@nvidia.com
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Reviewed-by: Ben Skeggs <bskeggs@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/gpu/drm/nouveau/include/nvif')
| -rw-r--r-- | drivers/gpu/drm/nouveau/include/nvif/if000c.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/gpu/drm/nouveau/include/nvif/if000c.h b/drivers/gpu/drm/nouveau/include/nvif/if000c.h index d6dd40f21eed..9c7ff56831c5 100644 --- a/drivers/gpu/drm/nouveau/include/nvif/if000c.h +++ b/drivers/gpu/drm/nouveau/include/nvif/if000c.h @@ -77,6 +77,7 @@ struct nvif_vmm_pfnmap_v0 { #define NVIF_VMM_PFNMAP_V0_APER 0x00000000000000f0ULL #define NVIF_VMM_PFNMAP_V0_HOST 0x0000000000000000ULL #define NVIF_VMM_PFNMAP_V0_VRAM 0x0000000000000010ULL +#define NVIF_VMM_PFNMAP_V0_A 0x0000000000000004ULL #define NVIF_VMM_PFNMAP_V0_W 0x0000000000000002ULL #define NVIF_VMM_PFNMAP_V0_V 0x0000000000000001ULL #define NVIF_VMM_PFNMAP_V0_NONE 0x0000000000000000ULL |