Re: [Nouveau] [PATCH v3 3/5] nouveau: fix mapping 2MB sysmem pages

From: Ben Skeggs
Date: Tue Jul 07 2020 - 23:20:10 EST


On Thu, 2 Jul 2020 at 08:54, Ralph Campbell <rcampbell@xxxxxxxxxx> wrote:
>
> The nvif_object_ioctl() method NVIF_VMM_V0_PFNMAP wasn't correctly
> setting the hardware specific GPU page table entries for 2MB sized
> pages. Fix this by adding functions to set and clear PD0 GPU page
> table entries.
I can take this one in my tree now, it's fairly independent of the rest.

Ben.

>
> Signed-off-by: Ralph Campbell <rcampbell@xxxxxxxxxx>
> ---
> drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.c | 5 +-
> .../drm/nouveau/nvkm/subdev/mmu/vmmgp100.c | 82 +++++++++++++++++++
> 2 files changed, 84 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.c b/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.c
> index 199f94e15c5f..19a6804e3989 100644
> --- a/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.c
> +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.c
> @@ -1204,7 +1204,6 @@ nvkm_vmm_pfn_unmap(struct nvkm_vmm *vmm, u64 addr, u64 size)
> /*TODO:
> * - Avoid PT readback (for dma_unmap etc), this might end up being dealt
> * with inside HMM, which would be a lot nicer for us to deal with.
> - * - Multiple page sizes (particularly for huge page support).
> * - Support for systems without a 4KiB page size.
> */
> int
> @@ -1220,8 +1219,8 @@ nvkm_vmm_pfn_map(struct nvkm_vmm *vmm, u8 shift, u64 addr, u64 size, u64 *pfn)
> /* Only support mapping where the page size of the incoming page
> * array matches a page size available for direct mapping.
> */
> - while (page->shift && page->shift != shift &&
> - page->desc->func->pfn == NULL)
> + while (page->shift && (page->shift != shift ||
> + page->desc->func->pfn == NULL))
> page++;
>
> if (!page->shift || !IS_ALIGNED(addr, 1ULL << shift) ||
> diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmmgp100.c b/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmmgp100.c
> index d86287565542..ed37fddd063f 100644
> --- a/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmmgp100.c
> +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmmgp100.c
> @@ -258,12 +258,94 @@ gp100_vmm_pd0_unmap(struct nvkm_vmm *vmm,
> VMM_FO128(pt, vmm, pdei * 0x10, 0ULL, 0ULL, pdes);
> }
>
> +static void
> +gp100_vmm_pd0_pfn_unmap(struct nvkm_vmm *vmm,
> + struct nvkm_mmu_pt *pt, u32 ptei, u32 ptes)
> +{
> + struct device *dev = vmm->mmu->subdev.device->dev;
> + dma_addr_t addr;
> +
> + nvkm_kmap(pt->memory);
> + while (ptes--) {
> + u32 datalo = nvkm_ro32(pt->memory, pt->base + ptei * 16 + 0);
> + u32 datahi = nvkm_ro32(pt->memory, pt->base + ptei * 16 + 4);
> + u64 data = (u64)datahi << 32 | datalo;
> +
> + if ((data & (3ULL << 1)) != 0) {
> + addr = (data >> 8) << 12;
> + dma_unmap_page(dev, addr, 1UL << 21, DMA_BIDIRECTIONAL);
> + }
> + ptei++;
> + }
> + nvkm_done(pt->memory);
> +}
> +
> +static bool
> +gp100_vmm_pd0_pfn_clear(struct nvkm_vmm *vmm,
> + struct nvkm_mmu_pt *pt, u32 ptei, u32 ptes)
> +{
> + bool dma = false;
> +
> + nvkm_kmap(pt->memory);
> + while (ptes--) {
> + u32 datalo = nvkm_ro32(pt->memory, pt->base + ptei * 16 + 0);
> + u32 datahi = nvkm_ro32(pt->memory, pt->base + ptei * 16 + 4);
> + u64 data = (u64)datahi << 32 | datalo;
> +
> + if ((data & BIT_ULL(0)) && (data & (3ULL << 1)) != 0) {
> + VMM_WO064(pt, vmm, ptei * 16, data & ~BIT_ULL(0));
> + dma = true;
> + }
> + ptei++;
> + }
> + nvkm_done(pt->memory);
> + return dma;
> +}
> +
> +static void
> +gp100_vmm_pd0_pfn(struct nvkm_vmm *vmm, struct nvkm_mmu_pt *pt,
> + u32 ptei, u32 ptes, struct nvkm_vmm_map *map)
> +{
> + struct device *dev = vmm->mmu->subdev.device->dev;
> + dma_addr_t addr;
> +
> + nvkm_kmap(pt->memory);
> + while (ptes--) {
> + u64 data = 0;
> +
> + if (!(*map->pfn & NVKM_VMM_PFN_W))
> + data |= BIT_ULL(6); /* RO. */
> +
> + if (!(*map->pfn & NVKM_VMM_PFN_VRAM)) {
> + addr = *map->pfn >> NVKM_VMM_PFN_ADDR_SHIFT;
> + addr = dma_map_page(dev, pfn_to_page(addr), 0,
> + 1UL << 21, DMA_BIDIRECTIONAL);
> + if (!WARN_ON(dma_mapping_error(dev, addr))) {
> + data |= addr >> 4;
> + data |= 2ULL << 1; /* SYSTEM_COHERENT_MEMORY. */
> + data |= BIT_ULL(3); /* VOL. */
> + data |= BIT_ULL(0); /* VALID. */
> + }
> + } else {
> + data |= (*map->pfn & NVKM_VMM_PFN_ADDR) >> 4;
> + data |= BIT_ULL(0); /* VALID. */
> + }
> +
> + VMM_WO064(pt, vmm, ptei++ * 16, data);
> + map->pfn++;
> + }
> + nvkm_done(pt->memory);
> +}
> +
> static const struct nvkm_vmm_desc_func
> gp100_vmm_desc_pd0 = {
> .unmap = gp100_vmm_pd0_unmap,
> .sparse = gp100_vmm_pd0_sparse,
> .pde = gp100_vmm_pd0_pde,
> .mem = gp100_vmm_pd0_mem,
> + .pfn = gp100_vmm_pd0_pfn,
> + .pfn_clear = gp100_vmm_pd0_pfn_clear,
> + .pfn_unmap = gp100_vmm_pd0_pfn_unmap,
> };
>
> static void
> --
> 2.20.1
>
> _______________________________________________
> Nouveau mailing list
> Nouveau@xxxxxxxxxxxxxxxxxxxxx
> https://lists.freedesktop.org/mailman/listinfo/nouveau