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, 17 insertions, 1 deletions

diff --git a/include/uapi/linux/nvgpu.h b/include/uapi/linux/nvgpu.h
index 0fa04f6b..38139524 100644
--- a/include/uapi/linux/nvgpu.h
+++ b/include/uapi/linux/nvgpu.h
@@ -1514,8 +1514,24 @@ struct nvgpu_channel_setup_bind_args {
 #define NVGPU_CHANNEL_SETUP_BIND_FLAGS_DETERMINISTIC    (1 << 1)
 /* enable replayable gmmu faults for this channel */
 #define NVGPU_CHANNEL_SETUP_BIND_FLAGS_REPLAYABLE_FAULTS_ENABLE   (1 << 2)
+/*
+ * Enable usermode submits on this channel.
+ *
+ * Submits in usermode are supported in some environments. If supported and
+ * this flag is set + USERD and GPFIFO buffers are provided here, a submit
+ * token is passed back to be written in the doorbell register in the usermode
+ * region to notify the GPU for new work on this channel. Usermode and
+ * kernelmode submit modes are mutually exclusive; by passing this flag, the
+ * SUBMIT_GPFIFO IOCTL cannot be used.
+ */
+#define NVGPU_CHANNEL_SETUP_BIND_FLAGS_USERMODE_SUPPORT (1 << 3)
         __u32 flags;
-        __u32 reserved[16];
+        __s32 userd_dmabuf_fd;  /* in */
+        __s32 gpfifo_dmabuf_fd; /* in */
+        __u32 work_submit_token; /* out */
+        __u64 userd_dmabuf_offset; /* in */
+        __u64 gpfifo_dmabuf_offset; /* in */
+        __u32 reserved[9];
 };
 struct nvgpu_fence {
         __u32 id;        /* syncpoint id or sync fence fd */