gpu: nvgpu: support usermode submit buffers

Import userd and gpfifo buffers from userspace if provided via
NVGPU_IOCTL_CHANNEL_ALLOC_GPFIFO_EX. Also supply the work submit token
(i.e., the hw channel id) to userspace.

To keep the buffers alive, store their dmabuf and attachment/sgt handles
in nvgpu_channel_linux. Our nvgpu_mem doesn't provide such data for
buffers that are mainly in kernel use. The buffers are freed via a new
API in the os_channel interface.

Fix a bug in gk20a_channel_free_usermode_buffers: also unmap the
usermode gpfifo buffer.

Bug 200145225
Bug 200541476

Change-Id: I8416af7085c91b044ac8ccd9faa38e2a6d0c3946
Signed-off-by: Konsta Holtta <kholtta@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1795821
Signed-off-by: Debarshi Dutta <ddutta@nvidia.com>
(cherry picked from commit 99b1c6dcdf328efcfe47338ad1b71a114ab7f272
in dev-main)
Reviewed-on: https://git-master.nvidia.com/r/2170603
GVS: Gerrit_Virtual_Submit
Reviewed-by: Bibek Basu <bbasu@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

1 files changed, 7 insertions, 2 deletions

diff --git a/drivers/gpu/nvgpu/common/fifo/channel.c b/drivers/gpu/nvgpu/common/fifo/channel.c
index adb59ac4..6ebeb596 100644
--- a/drivers/gpu/nvgpu/common/fifo/channel.c
+++ b/drivers/gpu/nvgpu/common/fifo/channel.c
@@ -1228,7 +1228,9 @@ int nvgpu_channel_setup_bind(struct channel_gk20a *c,
         nvgpu_log_info(g, "channel %d : gpfifo_base 0x%016llx, size %d",
                 c->chid, gpfifo_gpu_va, c->gpfifo.entry_num);
 
-        g->ops.fifo.setup_userd(c);
+        if (!c->usermode_submit_enabled) {
+                g->ops.fifo.setup_userd(c);
+        }
 
         if (g->aggressive_sync_destroy_thresh == 0U) {
                 nvgpu_mutex_acquire(&c->sync_lock);
@@ -1326,7 +1328,10 @@ void gk20a_channel_free_usermode_buffers(struct channel_gk20a *c)
                 nvgpu_dma_free(c->g, &c->usermode_userd);
         }
         if (nvgpu_mem_is_valid(&c->usermode_gpfifo)) {
-                nvgpu_dma_free(c->g, &c->usermode_gpfifo);
+                nvgpu_dma_unmap_free(c->vm, &c->usermode_gpfifo);
+        }
+        if (c->g->os_channel.free_usermode_buffers != NULL) {
+                c->g->os_channel.free_usermode_buffers(c);
         }
 }