[PATCH 1/2] drm/nouveau/ga102-: support ttm buffer moves via copy engine
Ben Skeggs
skeggsb at gmail.com
Tue Sep 7 00:46:28 UTC 2021
On Tue, 7 Sept 2021 at 10:28, Karol Herbst <kherbst at redhat.com> wrote:
>
> On Tue, Sep 7, 2021 at 1:28 AM Ben Skeggs <skeggsb at gmail.com> wrote:
> >
> > On Tue, 7 Sept 2021 at 09:17, Karol Herbst <kherbst at redhat.com> wrote:
> > >
> > > ."
> > >
> > >
> > > On Mon, Sep 6, 2021 at 2:56 AM Ben Skeggs <skeggsb at gmail.com> wrote:
> > > >
> > > > From: Ben Skeggs <bskeggs at redhat.com>
> > > >
> > > > We don't currently have any kind of real acceleration on Ampere GPUs,
> > > > but the TTM memcpy() fallback paths aren't really designed to handle
> > > > copies between different devices, such as on Optimus systems, and
> > > > result in a kernel OOPS.
> > > >
> > > > A few options were investigated to try and fix this, but didn't work
> > > > out, and likely would have resulted in a very unpleasant experience
> > > > for users anyway.
> > > >
> > > > This commit adds just enough support for setting up a single channel
> > > > connected to a copy engine, which the kernel can use to accelerate
> > > > the buffer copies between devices. Userspace has no access to this
> > > > incomplete channel support, but it's suitable for TTM's needs.
> > > >
> > > > A more complete implementation of host(fifo) for Ampere GPUs is in
> > > > the works, but the required changes are far too invasive that they
> > > > would be unsuitable to backport to fix this issue on current kernels.
> > > >
> > > > Signed-off-by: Ben Skeggs <bskeggs at redhat.com>
> > > > Cc: Lyude Paul <lyude at redhat.com>
> > > > Cc: Karol Herbst <kherbst at redhat.com>
> > > > Cc: <stable at vger.kernel.org> # v5.12+
> > > > ---
> > > > drivers/gpu/drm/nouveau/include/nvif/class.h | 2 +
> > > > .../drm/nouveau/include/nvkm/engine/fifo.h | 1 +
> > > > drivers/gpu/drm/nouveau/nouveau_bo.c | 1 +
> > > > drivers/gpu/drm/nouveau/nouveau_chan.c | 6 +-
> > > > drivers/gpu/drm/nouveau/nouveau_drm.c | 4 +
> > > > drivers/gpu/drm/nouveau/nv84_fence.c | 2 +-
> > > > .../gpu/drm/nouveau/nvkm/engine/device/base.c | 3 +
> > > > .../gpu/drm/nouveau/nvkm/engine/fifo/Kbuild | 1 +
> > > > .../gpu/drm/nouveau/nvkm/engine/fifo/ga102.c | 308 ++++++++++++++++++
> > > > .../gpu/drm/nouveau/nvkm/subdev/top/ga100.c | 7 +-
> > > > 10 files changed, 329 insertions(+), 6 deletions(-)
> > > > create mode 100644 drivers/gpu/drm/nouveau/nvkm/engine/fifo/ga102.c
> > > >
> > > > diff --git a/drivers/gpu/drm/nouveau/include/nvif/class.h b/drivers/gpu/drm/nouveau/include/nvif/class.h
> > > > index c68cc957248e..a582c0cb0cb0 100644
> > > > --- a/drivers/gpu/drm/nouveau/include/nvif/class.h
> > > > +++ b/drivers/gpu/drm/nouveau/include/nvif/class.h
> > > > @@ -71,6 +71,7 @@
> > > > #define PASCAL_CHANNEL_GPFIFO_A /* cla06f.h */ 0x0000c06f
> > > > #define VOLTA_CHANNEL_GPFIFO_A /* clc36f.h */ 0x0000c36f
> > > > #define TURING_CHANNEL_GPFIFO_A /* clc36f.h */ 0x0000c46f
> > > > +#define AMPERE_CHANNEL_GPFIFO_B /* clc36f.h */ 0x0000c76f
> > > >
> > > > #define NV50_DISP /* cl5070.h */ 0x00005070
> > > > #define G82_DISP /* cl5070.h */ 0x00008270
> > > > @@ -200,6 +201,7 @@
> > > > #define PASCAL_DMA_COPY_B 0x0000c1b5
> > > > #define VOLTA_DMA_COPY_A 0x0000c3b5
> > > > #define TURING_DMA_COPY_A 0x0000c5b5
> > > > +#define AMPERE_DMA_COPY_B 0x0000c7b5
> > > >
> > > > #define FERMI_DECOMPRESS 0x000090b8
> > > >
> > > > diff --git a/drivers/gpu/drm/nouveau/include/nvkm/engine/fifo.h b/drivers/gpu/drm/nouveau/include/nvkm/engine/fifo.h
> > > > index 54fab7cc36c1..64ee82c7c1be 100644
> > > > --- a/drivers/gpu/drm/nouveau/include/nvkm/engine/fifo.h
> > > > +++ b/drivers/gpu/drm/nouveau/include/nvkm/engine/fifo.h
> > > > @@ -77,4 +77,5 @@ int gp100_fifo_new(struct nvkm_device *, enum nvkm_subdev_type, int inst, struct
> > > > int gp10b_fifo_new(struct nvkm_device *, enum nvkm_subdev_type, int inst, struct nvkm_fifo **);
> > > > int gv100_fifo_new(struct nvkm_device *, enum nvkm_subdev_type, int inst, struct nvkm_fifo **);
> > > > int tu102_fifo_new(struct nvkm_device *, enum nvkm_subdev_type, int inst, struct nvkm_fifo **);
> > > > +int ga102_fifo_new(struct nvkm_device *, enum nvkm_subdev_type, int inst, struct nvkm_fifo **);
> > > > #endif
> > > > diff --git a/drivers/gpu/drm/nouveau/nouveau_bo.c b/drivers/gpu/drm/nouveau/nouveau_bo.c
> > > > index 4a7cebac8060..b3e4f555fa05 100644
> > > > --- a/drivers/gpu/drm/nouveau/nouveau_bo.c
> > > > +++ b/drivers/gpu/drm/nouveau/nouveau_bo.c
> > > > @@ -844,6 +844,7 @@ nouveau_bo_move_init(struct nouveau_drm *drm)
> > > > struct ttm_resource *, struct ttm_resource *);
> > > > int (*init)(struct nouveau_channel *, u32 handle);
> > > > } _methods[] = {
> > > > + { "COPY", 4, 0xc7b5, nve0_bo_move_copy, nve0_bo_move_init },
> > >
> > > so, I was looking at the COPY class headers and noticed something strange.
> > >
> > > "BYPASS_L2" was moved with MAXWELL_DMA_COPY_A from bit 11 to bit 20.
> > > It got split out to SRC_ (20) and DST_ (21) with PASCAL_DMA_COPY_A and
> > > got removed with AMPERE_DMA_COPY_A.
> > >
> > > Since MAXWELL_DMA_COPY_A bit 11 is FORCE_RMWDISABLE. I don't know if
> > > that causes any issues, I just noticed this while comparing the copy
> > > class headers.
> > Yeah, I think for the way we're using the CE for TTM moves, it's OK.
> > In the very least, no more wrong that it already is on existing GPUs
> > ;)
> >
> > >
> > > > { "COPY", 4, 0xc5b5, nve0_bo_move_copy, nve0_bo_move_init },
> > > > { "GRCE", 0, 0xc5b5, nve0_bo_move_copy, nvc0_bo_move_init },
> > > > { "COPY", 4, 0xc3b5, nve0_bo_move_copy, nve0_bo_move_init },
> > > > diff --git a/drivers/gpu/drm/nouveau/nouveau_chan.c b/drivers/gpu/drm/nouveau/nouveau_chan.c
> > > > index 80099ef75702..ea7769135b0d 100644
> > > > --- a/drivers/gpu/drm/nouveau/nouveau_chan.c
> > > > +++ b/drivers/gpu/drm/nouveau/nouveau_chan.c
> > > > @@ -250,7 +250,8 @@ static int
> > > > nouveau_channel_ind(struct nouveau_drm *drm, struct nvif_device *device,
> > > > u64 runlist, bool priv, struct nouveau_channel **pchan)
> > > > {
> > > > - static const u16 oclasses[] = { TURING_CHANNEL_GPFIFO_A,
> > > > + static const u16 oclasses[] = { AMPERE_CHANNEL_GPFIFO_B,
> > > > + TURING_CHANNEL_GPFIFO_A,
> > > > VOLTA_CHANNEL_GPFIFO_A,
> > > > PASCAL_CHANNEL_GPFIFO_A,
> > > > MAXWELL_CHANNEL_GPFIFO_A,
> > > > @@ -386,7 +387,8 @@ nouveau_channel_init(struct nouveau_channel *chan, u32 vram, u32 gart)
> > > >
> > > > nvif_object_map(&chan->user, NULL, 0);
> > > >
> > > > - if (chan->user.oclass >= FERMI_CHANNEL_GPFIFO) {
> > > > + if (chan->user.oclass >= FERMI_CHANNEL_GPFIFO &&
> > > > + chan->user.oclass < AMPERE_CHANNEL_GPFIFO_B) {
> > > > ret = nvif_notify_ctor(&chan->user, "abi16ChanKilled",
> > > > nouveau_channel_killed,
> > > > true, NV906F_V0_NTFY_KILLED,
> > > > diff --git a/drivers/gpu/drm/nouveau/nouveau_drm.c b/drivers/gpu/drm/nouveau/nouveau_drm.c
> > > > index 1f828c9f691c..6109cd9e3399 100644
> > > > --- a/drivers/gpu/drm/nouveau/nouveau_drm.c
> > > > +++ b/drivers/gpu/drm/nouveau/nouveau_drm.c
> > > > @@ -345,6 +345,9 @@ nouveau_accel_gr_init(struct nouveau_drm *drm)
> > > > u32 arg0, arg1;
> > > > int ret;
> > > >
> > > > + if (device->info.family >= NV_DEVICE_INFO_V0_AMPERE)
> > > > + return;
> > > > +
> > > > /* Allocate channel that has access to the graphics engine. */
> > > > if (device->info.family >= NV_DEVICE_INFO_V0_KEPLER) {
> > > > arg0 = nvif_fifo_runlist(device, NV_DEVICE_HOST_RUNLIST_ENGINES_GR);
> > > > @@ -469,6 +472,7 @@ nouveau_accel_init(struct nouveau_drm *drm)
> > > > case PASCAL_CHANNEL_GPFIFO_A:
> > > > case VOLTA_CHANNEL_GPFIFO_A:
> > > > case TURING_CHANNEL_GPFIFO_A:
> > > > + case AMPERE_CHANNEL_GPFIFO_B:
> > > > ret = nvc0_fence_create(drm);
> > > > break;
> > > > default:
> > > > diff --git a/drivers/gpu/drm/nouveau/nv84_fence.c b/drivers/gpu/drm/nouveau/nv84_fence.c
> > > > index 7c9c928c3196..c3526a8622e3 100644
> > > > --- a/drivers/gpu/drm/nouveau/nv84_fence.c
> > > > +++ b/drivers/gpu/drm/nouveau/nv84_fence.c
> > > > @@ -204,7 +204,7 @@ nv84_fence_create(struct nouveau_drm *drm)
> > > > priv->base.context_new = nv84_fence_context_new;
> > > > priv->base.context_del = nv84_fence_context_del;
> > > >
> > > > - priv->base.uevent = true;
> > > > + priv->base.uevent = drm->client.device.info.family < NV_DEVICE_INFO_V0_AMPERE;
> > > >
> > > > mutex_init(&priv->mutex);
> > > >
> > > > diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/device/base.c b/drivers/gpu/drm/nouveau/nvkm/engine/device/base.c
> > > > index 93ddf63d1114..ca75c5f6ecaf 100644
> > > > --- a/drivers/gpu/drm/nouveau/nvkm/engine/device/base.c
> > > > +++ b/drivers/gpu/drm/nouveau/nvkm/engine/device/base.c
> > > > @@ -2602,6 +2602,7 @@ nv172_chipset = {
> > > > .top = { 0x00000001, ga100_top_new },
> > > > .disp = { 0x00000001, ga102_disp_new },
> > > > .dma = { 0x00000001, gv100_dma_new },
> > > > + .fifo = { 0x00000001, ga102_fifo_new },
> > > > };
> > > >
> > > > static const struct nvkm_device_chip
> > > > @@ -2622,6 +2623,7 @@ nv174_chipset = {
> > > > .top = { 0x00000001, ga100_top_new },
> > > > .disp = { 0x00000001, ga102_disp_new },
> > > > .dma = { 0x00000001, gv100_dma_new },
> > > > + .fifo = { 0x00000001, ga102_fifo_new },
> > > > };
> > > >
> > > > static const struct nvkm_device_chip
> > > > @@ -2642,6 +2644,7 @@ nv177_chipset = {
> > > > .top = { 0x00000001, ga100_top_new },
> > > > .disp = { 0x00000001, ga102_disp_new },
> > > > .dma = { 0x00000001, gv100_dma_new },
> > > > + .fifo = { 0x00000001, ga102_fifo_new },
> > > > };
> > > >
> > > > static int
> > > > diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/Kbuild b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/Kbuild
> > > > index 3209eb7af65f..5e831d347a95 100644
> > > > --- a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/Kbuild
> > > > +++ b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/Kbuild
> > > > @@ -18,6 +18,7 @@ nvkm-y += nvkm/engine/fifo/gp100.o
> > > > nvkm-y += nvkm/engine/fifo/gp10b.o
> > > > nvkm-y += nvkm/engine/fifo/gv100.o
> > > > nvkm-y += nvkm/engine/fifo/tu102.o
> > > > +nvkm-y += nvkm/engine/fifo/ga102.o
> > > >
> > > > nvkm-y += nvkm/engine/fifo/chan.o
> > > > nvkm-y += nvkm/engine/fifo/channv50.o
> > > > diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/ga102.c b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/ga102.c
> > > > new file mode 100644
> > > > index 000000000000..bfb66457100c
> > > > --- /dev/null
> > > > +++ b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/ga102.c
> > > > @@ -0,0 +1,308 @@
> > > > +/*
> > > > + * Copyright 2021 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.
> > > > + */
> > > > +#define ga102_fifo(p) container_of((p), struct ga102_fifo, base.engine)
> > > > +#define ga102_chan(p) container_of((p), struct ga102_chan, object)
> > > > +#include <engine/fifo.h>
> > > > +#include "user.h"
> > > > +
> > > > +#include <core/memory.h>
> > > > +#include <subdev/mmu.h>
> > > > +#include <subdev/timer.h>
> > > > +#include <subdev/top.h>
> > > > +
> > > > +#include <nvif/cl0080.h>
> > > > +#include <nvif/clc36f.h>
> > > > +#include <nvif/class.h>
> > > > +
> > > > +struct ga102_fifo {
> > > > + struct nvkm_fifo base;
> > > > +};
> > > > +
> > > > +struct ga102_chan {
> > > > + struct nvkm_object object;
> > > > +
> > > > + struct {
> > > > + u32 runl;
> > > > + u32 chan;
> > > > + } ctrl;
> > > > +
> > > > + struct nvkm_memory *mthd;
> > > > + struct nvkm_memory *inst;
> > > > + struct nvkm_memory *user;
> > > > + struct nvkm_memory *runl;
> > > > +
> > > > + struct nvkm_vmm *vmm;
> > > > +};
> > > > +
> > > > +static int
> > > > +ga102_chan_sclass(struct nvkm_object *object, int index, struct nvkm_oclass *oclass)
> > > > +{
> > > > + if (index == 0) {
> > > > + oclass->ctor = nvkm_object_new;
> > > > + oclass->base = (struct nvkm_sclass) { -1, -1, AMPERE_DMA_COPY_B };
> > > > + return 0;
> > > > + }
> > > > +
> > > > + return -EINVAL;
> > > > +}
> > > > +
> > > > +static int
> > > > +ga102_chan_map(struct nvkm_object *object, void *argv, u32 argc,
> > > > + enum nvkm_object_map *type, u64 *addr, u64 *size)
> > > > +{
> > > > + struct ga102_chan *chan = ga102_chan(object);
> > > > + struct nvkm_device *device = chan->object.engine->subdev.device;
> > > > + u64 bar2 = nvkm_memory_bar2(chan->user);
> > > > +
> > > > + if (bar2 == ~0ULL)
> > > > + return -EFAULT;
> > > > +
> > > > + *type = NVKM_OBJECT_MAP_IO;
> > > > + *addr = device->func->resource_addr(device, 3) + bar2;
> > > > + *size = 0x1000;
> > > > + return 0;
> > > > +}
> > > > +
> > > > +static int
> > > > +ga102_chan_fini(struct nvkm_object *object, bool suspend)
> > > > +{
> > > > + struct ga102_chan *chan = ga102_chan(object);
> > > > + struct nvkm_device *device = chan->object.engine->subdev.device;
> > > > +
> > > > + nvkm_wr32(device, chan->ctrl.chan, 0x00000003);
> > > > +
> > > > + nvkm_wr32(device, chan->ctrl.runl + 0x098, 0x01000000);
> > > > + nvkm_msec(device, 2000,
> > > > + if (!(nvkm_rd32(device, chan->ctrl.runl + 0x098) & 0x00100000))
> > > > + break;
> > > > + );
> > > > +
> > > > + nvkm_wr32(device, chan->ctrl.runl + 0x088, 0);
> > > > +
> > > > + nvkm_wr32(device, chan->ctrl.chan, 0xffffffff);
> > > > + return 0;
> > > > +}
> > > > +
> > > > +static int
> > > > +ga102_chan_init(struct nvkm_object *object)
> > > > +{
> > > > + struct ga102_chan *chan = ga102_chan(object);
> > > > + struct nvkm_device *device = chan->object.engine->subdev.device;
> > > > +
> > > > + nvkm_mask(device, chan->ctrl.runl + 0x300, 0x80000000, 0x80000000);
> > > > +
> > > > + nvkm_wr32(device, chan->ctrl.runl + 0x080, lower_32_bits(nvkm_memory_addr(chan->runl)));
> > > > + nvkm_wr32(device, chan->ctrl.runl + 0x084, upper_32_bits(nvkm_memory_addr(chan->runl)));
> > > > + nvkm_wr32(device, chan->ctrl.runl + 0x088, 2);
> > > > +
> > > > + nvkm_wr32(device, chan->ctrl.chan, 0x00000002);
> > > > + nvkm_wr32(device, chan->ctrl.runl + 0x0090, 0);
> > > > + return 0;
> > > > +}
> > > > +
> > > > +static void *
> > > > +ga102_chan_dtor(struct nvkm_object *object)
> > > > +{
> > > > + struct ga102_chan *chan = ga102_chan(object);
> > > > +
> > > > + if (chan->vmm) {
> > > > + nvkm_vmm_part(chan->vmm, chan->inst);
> > > > + nvkm_vmm_unref(&chan->vmm);
> > > > + }
> > > > +
> > > > + nvkm_memory_unref(&chan->runl);
> > > > + nvkm_memory_unref(&chan->user);
> > > > + nvkm_memory_unref(&chan->inst);
> > > > + nvkm_memory_unref(&chan->mthd);
> > > > + return chan;
> > > > +}
> > > > +
> > > > +static const struct nvkm_object_func
> > > > +ga102_chan = {
> > > > + .dtor = ga102_chan_dtor,
> > > > + .init = ga102_chan_init,
> > > > + .fini = ga102_chan_fini,
> > > > + .map = ga102_chan_map,
> > > > + .sclass = ga102_chan_sclass,
> > > > +};
> > > > +
> > > > +static int
> > > > +ga102_chan_new(struct nvkm_device *device,
> > > > + const struct nvkm_oclass *oclass, void *argv, u32 argc, struct nvkm_object **pobject)
> > > > +{
> > > > + struct volta_channel_gpfifo_a_v0 *args = argv;
> > > > + struct nvkm_top_device *tdev;
> > > > + struct nvkm_vmm *vmm;
> > > > + struct ga102_chan *chan;
> > > > + int ret;
> > > > +
> > > > + if (argc != sizeof(*args))
> > > > + return -ENOSYS;
> > > > +
> > > > + vmm = nvkm_uvmm_search(oclass->client, args->vmm);
> > > > + if (IS_ERR(vmm))
> > > > + return PTR_ERR(vmm);
> > > > +
> > > > + if (!(chan = kzalloc(sizeof(*chan), GFP_KERNEL)))
> > > > + return -ENOMEM;
> > > > +
> > > > + nvkm_object_ctor(&ga102_chan, oclass, &chan->object);
> > > > + *pobject = &chan->object;
> > > > +
> > > > + list_for_each_entry(tdev, &device->top->device, head) {
> > > > + if (tdev->type == NVKM_ENGINE_CE) {
> > > > + chan->ctrl.runl = tdev->runlist;
> > > > + break;
> > > > + }
> > > > + }
> > > > +
> > > > + if (!chan->ctrl.runl)
> > > > + return -ENODEV;
> > > > +
> > > > + chan->ctrl.chan = nvkm_rd32(device, chan->ctrl.runl + 0x004) & 0xfffffff0;
> > > > + args->token = nvkm_rd32(device, chan->ctrl.runl + 0x008) & 0xffff0000;
> > > > +
> > > > + ret = nvkm_memory_new(device, NVKM_MEM_TARGET_INST, 0x1000, 0x1000, true, &chan->mthd);
> > > > + if (ret)
> > > > + return ret;
> > > > +
> > > > + ret = nvkm_memory_new(device, NVKM_MEM_TARGET_INST, 0x1000, 0x1000, true, &chan->inst);
> > > > + if (ret)
> > > > + return ret;
> > > > +
> > > > + nvkm_kmap(chan->inst);
> > > > + nvkm_wo32(chan->inst, 0x010, 0x0000face);
> > > > + nvkm_wo32(chan->inst, 0x030, 0x7ffff902);
> > > > + nvkm_wo32(chan->inst, 0x048, lower_32_bits(args->ioffset));
> > > > + nvkm_wo32(chan->inst, 0x04c, upper_32_bits(args->ioffset) |
> > > > + (order_base_2(args->ilength) << 16));
> > > > + nvkm_wo32(chan->inst, 0x084, 0x20400000);
> > > > + nvkm_wo32(chan->inst, 0x094, 0x30000001);
> > > > + nvkm_wo32(chan->inst, 0x0ac, 0x00020000);
> > > > + nvkm_wo32(chan->inst, 0x0e4, 0x00000000);
> > > > + nvkm_wo32(chan->inst, 0x0e8, 0);
> > > > + nvkm_wo32(chan->inst, 0x0f4, 0x00001000);
> > > > + nvkm_wo32(chan->inst, 0x0f8, 0x10003080);
> > > > + nvkm_mo32(chan->inst, 0x218, 0x00000000, 0x00000000);
> > > > + nvkm_wo32(chan->inst, 0x220, lower_32_bits(nvkm_memory_bar2(chan->mthd)));
> > > > + nvkm_wo32(chan->inst, 0x224, upper_32_bits(nvkm_memory_bar2(chan->mthd)));
> > > > + nvkm_done(chan->inst);
> > > > +
> > > > + ret = nvkm_memory_new(device, NVKM_MEM_TARGET_INST, 0x1000, 0x1000, true, &chan->user);
> > > > + if (ret)
> > > > + return ret;
> > > > +
> > > > + ret = nvkm_memory_new(device, NVKM_MEM_TARGET_INST, 0x1000, 0x1000, true, &chan->runl);
> > > > + if (ret)
> > > > + return ret;
> > > > +
> > > > + nvkm_kmap(chan->runl);
> > > > + nvkm_wo32(chan->runl, 0x00, 0x80030001);
> > > > + nvkm_wo32(chan->runl, 0x04, 1);
> > > > + nvkm_wo32(chan->runl, 0x08, 0);
> > > > + nvkm_wo32(chan->runl, 0x0c, 0x00000000);
> > > > + nvkm_wo32(chan->runl, 0x10, lower_32_bits(nvkm_memory_addr(chan->user)));
> > > > + nvkm_wo32(chan->runl, 0x14, upper_32_bits(nvkm_memory_addr(chan->user)));
> > > > + nvkm_wo32(chan->runl, 0x18, lower_32_bits(nvkm_memory_addr(chan->inst)));
> > > > + nvkm_wo32(chan->runl, 0x1c, upper_32_bits(nvkm_memory_addr(chan->inst)));
> > > > + nvkm_done(chan->runl);
> > >
> > > Do we actually have documentation on what those offsets all mean?
> > > (same for chan->inst above(
> > Yes. The chan->inst stuff is NV_RAMFC (dev_ram.ref), and the copy
> > engine context data. The chan->runl stuff is NV_RAMRL (also
> > dev_ram.ref). It's actually almost identical to GV100, though RAMFC
> > lost USERD fields, they're only specified in the RAMRL entry now. The
> > code is shared in the full host implementation I'm trying to finish
> > up.
> >
>
> oh wow, that file has actual documentation.
>
> Cool, actually something to read through and understand :D Anyway, it
> seems like it actually is just like the volta code, just with more
> hard coded bits.
>
> Overall I think the code is fine, so a
>
> Reviewed-by: Karol Herbst <kherbst at redhat.com>
>
> I just don't know if I should feel comfortable getting into stable
> kernels or not, but as it does "fixes" prime offloading, even though
> it's more "enabling" than anything else. I think we might want to
> either add such a workaround for future gens as well or try to
> disallow setting up offloading? Not sure. If others are fine with it,
> so am I :)
It's the first time this situation has happened actually, usually
host/ce support appears in the "initial support" without firmware.
Disabling prime was the last-resort option, though it means most
laptops with external displays won't work, which is... Not great. I
decided to see how awful it'd be to hack up something just for this
temporarily, and throw it out there to see. It should be safe
(definitely for earlier chipsets), and the result otherwise is an
OOPS, so, probably worth it on the whole.
Ben.
>
>
> > >
> > > > +
> > > > + ret = nvkm_vmm_join(vmm, chan->inst);
> > > > + if (ret)
> > > > + return ret;
> > > > +
> > > > + chan->vmm = nvkm_vmm_ref(vmm);
> > > > + return 0;
> > > > +}
> > > > +
> > > > +static const struct nvkm_device_oclass
> > > > +ga102_chan_oclass = {
> > > > + .ctor = ga102_chan_new,
> > > > +};
> > > > +
> > > > +static int
> > > > +ga102_user_new(struct nvkm_device *device,
> > > > + const struct nvkm_oclass *oclass, void *argv, u32 argc, struct nvkm_object **pobject)
> > > > +{
> > > > + return tu102_fifo_user_new(oclass, argv, argc, pobject);
> > > > +}
> > > > +
> > > > +static const struct nvkm_device_oclass
> > > > +ga102_user_oclass = {
> > > > + .ctor = ga102_user_new,
> > > > +};
> > > > +
> > > > +static int
> > > > +ga102_fifo_sclass(struct nvkm_oclass *oclass, int index, const struct nvkm_device_oclass **class)
> > > > +{
> > > > + if (index == 0) {
> > > > + oclass->base = (struct nvkm_sclass) { -1, -1, VOLTA_USERMODE_A };
> > > > + *class = &ga102_user_oclass;
> > > > + return 0;
> > > > + } else
> > > > + if (index == 1) {
> > > > + oclass->base = (struct nvkm_sclass) { 0, 0, AMPERE_CHANNEL_GPFIFO_B };
> > > > + *class = &ga102_chan_oclass;
> > > > + return 0;
> > > > + }
> > > > +
> > > > + return 2;
> > > > +}
> > > > +
> > > > +static int
> > > > +ga102_fifo_info(struct nvkm_engine *engine, u64 mthd, u64 *data)
> > > > +{
> > > > + switch (mthd) {
> > > > + case NV_DEVICE_HOST_CHANNELS: *data = 1; return 0;
> > > > + default:
> > > > + break;
> > > > + }
> > > > +
> > > > + return -ENOSYS;
> > > > +}
> > > > +
> > > > +static void *
> > > > +ga102_fifo_dtor(struct nvkm_engine *engine)
> > > > +{
> > > > + return ga102_fifo(engine);
> > > > +}
> > > > +
> > > > +static const struct nvkm_engine_func
> > > > +ga102_fifo = {
> > > > + .dtor = ga102_fifo_dtor,
> > > > + .info = ga102_fifo_info,
> > > > + .base.sclass = ga102_fifo_sclass,
> > > > +};
> > > > +
> > > > +int
> > > > +ga102_fifo_new(struct nvkm_device *device, enum nvkm_subdev_type type, int inst,
> > > > + struct nvkm_fifo **pfifo)
> > > > +{
> > > > + struct ga102_fifo *fifo;
> > > > +
> > > > + if (!(fifo = kzalloc(sizeof(*fifo), GFP_KERNEL)))
> > > > + return -ENOMEM;
> > > > +
> > > > + nvkm_engine_ctor(&ga102_fifo, device, type, inst, true, &fifo->base.engine);
> > > > + *pfifo = &fifo->base;
> > > > + return 0;
> > > > +}
> > > > diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/top/ga100.c b/drivers/gpu/drm/nouveau/nvkm/subdev/top/ga100.c
> > > > index 31933f3e5a07..c982d834c8d9 100644
> > > > --- a/drivers/gpu/drm/nouveau/nvkm/subdev/top/ga100.c
> > > > +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/top/ga100.c
> > > > @@ -54,7 +54,7 @@ ga100_top_oneinit(struct nvkm_top *top)
> > > > info->reset = (data & 0x0000001f);
> > > > break;
> > > > case 2:
> > > > - info->runlist = (data & 0x0000fc00) >> 10;
> > > > + info->runlist = (data & 0x00fffc00);
> > > > info->engine = (data & 0x00000003);
> > > > break;
> > > > default:
> > > > @@ -85,9 +85,10 @@ ga100_top_oneinit(struct nvkm_top *top)
> > > > }
> > > >
> > > > nvkm_debug(subdev, "%02x.%d (%8s): addr %06x fault %2d "
> > > > - "runlist %2d engine %2d reset %2d\n", type, inst,
> > > > + "runlist %6x engine %2d reset %2d\n", type, inst,
> > > > info->type == NVKM_SUBDEV_NR ? "????????" : nvkm_subdev_type[info->type],
> > > > - info->addr, info->fault, info->runlist, info->engine, info->reset);
> > > > + info->addr, info->fault, info->runlist < 0 ? 0 : info->runlist,
> > > > + info->engine, info->reset);
> > > > info = NULL;
> > > > }
> > > >
> > > > --
> > > > 2.31.1
> > > >
> > >
> > > Overall the changes look fine. I don't know if the ampere
> > > implementation is itself correct, but the surrounding is fine imho.
> > >
> >
>
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