linux/drivers/gpu/drm/nouveau/nouveau_vmm.c
Ben Skeggs eeaf06ac1a drm/nouveau/svm: initial support for shared virtual memory
This uses HMM to mirror a process' CPU page tables into a channel's page
tables, and keep them synchronised so that both the CPU and GPU are able
to access the same memory at the same virtual address.

While this code also supports Volta/Turing, it's only enabled for Pascal
GPUs currently due to channel recovery being unreliable right now on the
later GPUs.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
2019-02-20 09:00:02 +10:00

139 lines
3.4 KiB
C

/*
* Copyright 2017 Red Hat Inc.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*/
#include "nouveau_vmm.h"
#include "nouveau_drv.h"
#include "nouveau_bo.h"
#include "nouveau_svm.h"
#include "nouveau_mem.h"
void
nouveau_vma_unmap(struct nouveau_vma *vma)
{
if (vma->mem) {
nvif_vmm_unmap(&vma->vmm->vmm, vma->addr);
vma->mem = NULL;
}
}
int
nouveau_vma_map(struct nouveau_vma *vma, struct nouveau_mem *mem)
{
struct nvif_vma tmp = { .addr = vma->addr };
int ret = nouveau_mem_map(mem, &vma->vmm->vmm, &tmp);
if (ret)
return ret;
vma->mem = mem;
return 0;
}
struct nouveau_vma *
nouveau_vma_find(struct nouveau_bo *nvbo, struct nouveau_vmm *vmm)
{
struct nouveau_vma *vma;
list_for_each_entry(vma, &nvbo->vma_list, head) {
if (vma->vmm == vmm)
return vma;
}
return NULL;
}
void
nouveau_vma_del(struct nouveau_vma **pvma)
{
struct nouveau_vma *vma = *pvma;
if (vma && --vma->refs <= 0) {
if (likely(vma->addr != ~0ULL)) {
struct nvif_vma tmp = { .addr = vma->addr, .size = 1 };
nvif_vmm_put(&vma->vmm->vmm, &tmp);
}
list_del(&vma->head);
kfree(*pvma);
*pvma = NULL;
}
}
int
nouveau_vma_new(struct nouveau_bo *nvbo, struct nouveau_vmm *vmm,
struct nouveau_vma **pvma)
{
struct nouveau_mem *mem = nouveau_mem(&nvbo->bo.mem);
struct nouveau_vma *vma;
struct nvif_vma tmp;
int ret;
if ((vma = *pvma = nouveau_vma_find(nvbo, vmm))) {
vma->refs++;
return 0;
}
if (!(vma = *pvma = kmalloc(sizeof(*vma), GFP_KERNEL)))
return -ENOMEM;
vma->vmm = vmm;
vma->refs = 1;
vma->addr = ~0ULL;
vma->mem = NULL;
vma->fence = NULL;
list_add_tail(&vma->head, &nvbo->vma_list);
if (nvbo->bo.mem.mem_type != TTM_PL_SYSTEM &&
mem->mem.page == nvbo->page) {
ret = nvif_vmm_get(&vmm->vmm, LAZY, false, mem->mem.page, 0,
mem->mem.size, &tmp);
if (ret)
goto done;
vma->addr = tmp.addr;
ret = nouveau_vma_map(vma, mem);
} else {
ret = nvif_vmm_get(&vmm->vmm, PTES, false, mem->mem.page, 0,
mem->mem.size, &tmp);
vma->addr = tmp.addr;
}
done:
if (ret)
nouveau_vma_del(pvma);
return ret;
}
void
nouveau_vmm_fini(struct nouveau_vmm *vmm)
{
nouveau_svmm_fini(&vmm->svmm);
nvif_vmm_fini(&vmm->vmm);
vmm->cli = NULL;
}
int
nouveau_vmm_init(struct nouveau_cli *cli, s32 oclass, struct nouveau_vmm *vmm)
{
int ret = nvif_vmm_init(&cli->mmu, oclass, false, PAGE_SIZE, 0, NULL, 0,
&vmm->vmm);
if (ret)
return ret;
vmm->cli = cli;
return 0;
}