drm/nouveau/svm: map pages after migration

When memory is migrated to the GPU, it is likely to be accessed by GPU
code soon afterwards. Instead of waiting for a GPU fault, map the
migrated memory into the GPU page tables with the same access permissions
as the source CPU page table entries. This preserves copy on write
semantics.

Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
This commit is contained in:
Ralph Campbell 2020-03-03 16:13:39 -08:00 committed by Ben Skeggs
parent 9c1c08a68d
commit e3d8b08904
4 changed files with 95 additions and 17 deletions

View File

@ -25,12 +25,14 @@
#include "nouveau_dma.h"
#include "nouveau_mem.h"
#include "nouveau_bo.h"
#include "nouveau_svm.h"
#include <nvif/class.h>
#include <nvif/object.h>
#include <nvif/if000c.h>
#include <nvif/if500b.h>
#include <nvif/if900b.h>
#include <nvif/if000c.h>
#include <linux/sched/mm.h>
#include <linux/hmm.h>
@ -561,10 +563,11 @@ out_free:
}
static unsigned long nouveau_dmem_migrate_copy_one(struct nouveau_drm *drm,
unsigned long src, dma_addr_t *dma_addr)
unsigned long src, dma_addr_t *dma_addr, u64 *pfn)
{
struct device *dev = drm->dev->dev;
struct page *dpage, *spage;
unsigned long paddr;
spage = migrate_pfn_to_page(src);
if (!spage || !(src & MIGRATE_PFN_MIGRATE))
@ -572,17 +575,21 @@ static unsigned long nouveau_dmem_migrate_copy_one(struct nouveau_drm *drm,
dpage = nouveau_dmem_page_alloc_locked(drm);
if (!dpage)
return 0;
goto out;
*dma_addr = dma_map_page(dev, spage, 0, PAGE_SIZE, DMA_BIDIRECTIONAL);
if (dma_mapping_error(dev, *dma_addr))
goto out_free_page;
paddr = nouveau_dmem_page_addr(dpage);
if (drm->dmem->migrate.copy_func(drm, 1, NOUVEAU_APER_VRAM,
nouveau_dmem_page_addr(dpage), NOUVEAU_APER_HOST,
*dma_addr))
paddr, NOUVEAU_APER_HOST, *dma_addr))
goto out_dma_unmap;
*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)
*pfn |= NVIF_VMM_PFNMAP_V0_W;
return migrate_pfn(page_to_pfn(dpage)) | MIGRATE_PFN_LOCKED;
out_dma_unmap:
@ -590,18 +597,20 @@ out_dma_unmap:
out_free_page:
nouveau_dmem_page_free_locked(drm, dpage);
out:
*pfn = NVIF_VMM_PFNMAP_V0_NONE;
return 0;
}
static void nouveau_dmem_migrate_chunk(struct nouveau_drm *drm,
struct migrate_vma *args, dma_addr_t *dma_addrs)
struct nouveau_svmm *svmm, struct migrate_vma *args,
dma_addr_t *dma_addrs, u64 *pfns)
{
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);
dma_addrs + nr_dma, pfns + i);
if (args->dst[i])
nr_dma++;
addr += PAGE_SIZE;
@ -610,20 +619,18 @@ static void nouveau_dmem_migrate_chunk(struct nouveau_drm *drm,
nouveau_fence_new(drm->dmem->migrate.chan, false, &fence);
migrate_vma_pages(args);
nouveau_dmem_fence_done(&fence);
nouveau_pfns_map(svmm, args->vma->vm_mm, args->start, pfns, i);
while (nr_dma--) {
dma_unmap_page(drm->dev->dev, dma_addrs[nr_dma], PAGE_SIZE,
DMA_BIDIRECTIONAL);
}
/*
* FIXME optimization: update GPU page table to point to newly migrated
* memory.
*/
migrate_vma_finalize(args);
}
int
nouveau_dmem_migrate_vma(struct nouveau_drm *drm,
struct nouveau_svmm *svmm,
struct vm_area_struct *vma,
unsigned long start,
unsigned long end)
@ -635,7 +642,8 @@ nouveau_dmem_migrate_vma(struct nouveau_drm *drm,
.vma = vma,
.start = start,
};
unsigned long c, i;
unsigned long i;
u64 *pfns;
int ret = -ENOMEM;
args.src = kcalloc(max, sizeof(*args.src), GFP_KERNEL);
@ -649,19 +657,25 @@ nouveau_dmem_migrate_vma(struct nouveau_drm *drm,
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)
pfns = nouveau_pfns_alloc(max);
if (!pfns)
goto out_free_dma;
for (i = 0; i < npages; i += max) {
args.end = start + (max << PAGE_SHIFT);
ret = migrate_vma_setup(&args);
if (ret)
goto out_free_pfns;
if (args.cpages)
nouveau_dmem_migrate_chunk(drm, &args, dma_addrs);
nouveau_dmem_migrate_chunk(drm, svmm, &args, dma_addrs,
pfns);
args.start = args.end;
}
ret = 0;
out_free_pfns:
nouveau_pfns_free(pfns);
out_free_dma:
kfree(dma_addrs);
out_free_dst:

View File

@ -25,6 +25,7 @@
struct drm_device;
struct drm_file;
struct nouveau_drm;
struct nouveau_svmm;
struct hmm_range;
#if IS_ENABLED(CONFIG_DRM_NOUVEAU_SVM)
@ -34,6 +35,7 @@ void nouveau_dmem_suspend(struct nouveau_drm *);
void nouveau_dmem_resume(struct nouveau_drm *);
int nouveau_dmem_migrate_vma(struct nouveau_drm *drm,
struct nouveau_svmm *svmm,
struct vm_area_struct *vma,
unsigned long start,
unsigned long end);

View File

@ -70,6 +70,12 @@ struct nouveau_svm {
#define SVM_DBG(s,f,a...) NV_DEBUG((s)->drm, "svm: "f"\n", ##a)
#define SVM_ERR(s,f,a...) NV_WARN((s)->drm, "svm: "f"\n", ##a)
struct nouveau_pfnmap_args {
struct nvif_ioctl_v0 i;
struct nvif_ioctl_mthd_v0 m;
struct nvif_vmm_pfnmap_v0 p;
};
struct nouveau_ivmm {
struct nouveau_svmm *svmm;
u64 inst;
@ -187,7 +193,8 @@ nouveau_svmm_bind(struct drm_device *dev, void *data,
addr = max(addr, vma->vm_start);
next = min(vma->vm_end, end);
/* This is a best effort so we ignore errors */
nouveau_dmem_migrate_vma(cli->drm, vma, addr, next);
nouveau_dmem_migrate_vma(cli->drm, cli->svm.svmm, vma, addr,
next);
addr = next;
}
@ -784,6 +791,56 @@ nouveau_svm_fault(struct nvif_notify *notify)
return NVIF_NOTIFY_KEEP;
}
static struct nouveau_pfnmap_args *
nouveau_pfns_to_args(void *pfns)
{
return container_of(pfns, struct nouveau_pfnmap_args, p.phys);
}
u64 *
nouveau_pfns_alloc(unsigned long npages)
{
struct nouveau_pfnmap_args *args;
args = kzalloc(struct_size(args, p.phys, npages), GFP_KERNEL);
if (!args)
return NULL;
args->i.type = NVIF_IOCTL_V0_MTHD;
args->m.method = NVIF_VMM_V0_PFNMAP;
args->p.page = PAGE_SHIFT;
return args->p.phys;
}
void
nouveau_pfns_free(u64 *pfns)
{
struct nouveau_pfnmap_args *args = nouveau_pfns_to_args(pfns);
kfree(args);
}
void
nouveau_pfns_map(struct nouveau_svmm *svmm, struct mm_struct *mm,
unsigned long addr, u64 *pfns, unsigned long npages)
{
struct nouveau_pfnmap_args *args = nouveau_pfns_to_args(pfns);
int ret;
args->p.addr = addr;
args->p.size = npages << PAGE_SHIFT;
mutex_lock(&svmm->mutex);
svmm->vmm->vmm.object.client->super = true;
ret = nvif_object_ioctl(&svmm->vmm->vmm.object, args, sizeof(*args) +
npages * sizeof(args->p.phys[0]), NULL);
svmm->vmm->vmm.object.client->super = false;
mutex_unlock(&svmm->mutex);
}
static void
nouveau_svm_fault_buffer_fini(struct nouveau_svm *svm, int id)
{

View File

@ -18,6 +18,11 @@ void nouveau_svmm_fini(struct nouveau_svmm **);
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 *);
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,
unsigned long addr, u64 *pfns, unsigned long npages);
#else /* IS_ENABLED(CONFIG_DRM_NOUVEAU_SVM) */
static inline void nouveau_svm_init(struct nouveau_drm *drm) {}
static inline void nouveau_svm_fini(struct nouveau_drm *drm) {}