[PATCH 2/3] drm/amdgpu: Add ioctl infra for exporting/importing UALink handles

[Alex Deucher <alexander.deucher@amd.com>]

From: Mukul Joshi <mukul.joshi@amd.com>

Add the ioctl infrastructure to support exporting and importing BOs
to facilitate NPA based memory sharing across GPUs in a rack scale
setup.

Proposed userspace:
https://github.com/ROCm/rocm-systems/blob/35959f8e1260c7cee3e51a740e320be3856ee4ff/projects/rocr-runtime/libhsakmt/src/memory.c#L971
https://github.com/ROCm/rocm-systems/blob/35959f8e1260c7cee3e51a740e320be3856ee4ff/projects/rocr-runtime/libhsakmt/src/memory.c#L1036

v2: Move the ioctl wire-up to the end of the series.

Signed-off-by: Mukul Joshi <mukul.joshi@amd.com>
Signed-off-by: Horatio Zhang <hongkun.zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c    |  2 +
 drivers/gpu/drm/amd/amdgpu/amdgpu_ualink.c | 44 ++++++++++++++++++++++
 drivers/gpu/drm/amd/amdgpu/amdgpu_ualink.h |  2 +
 include/uapi/drm/amdgpu_drm.h              | 30 +++++++++++++++
 4 files changed, 78 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
index 04b21e456fbc0..25430ff39a6c0 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
@@ -54,6 +54,7 @@
 #include "amdgpu_userq.h"
 #include "amdgpu_userq_fence.h"
 #include "../amdxcp/amdgpu_xcp_drv.h"
+#include "amdgpu_ualink.h"
 
 /*
  * KMS wrapper.
@@ -3119,6 +3120,7 @@ const struct drm_ioctl_desc amdgpu_ioctls_kms[] = {
 	DRM_IOCTL_DEF_DRV(AMDGPU_USERQ_WAIT, amdgpu_userq_wait_ioctl, DRM_AUTH|DRM_RENDER_ALLOW),
 	DRM_IOCTL_DEF_DRV(AMDGPU_GEM_LIST_HANDLES, amdgpu_gem_list_handles_ioctl, DRM_AUTH|DRM_RENDER_ALLOW),
 	DRM_IOCTL_DEF_DRV(AMDGPU_PROC_OPTIONS, amdgpu_proc_options_ioctl, DRM_AUTH|DRM_RENDER_ALLOW),
+	DRM_IOCTL_DEF_DRV(AMDGPU_UALINK_HANDLE, amdgpu_gem_ualink_handle_ioctl, DRM_AUTH|DRM_RENDER_ALLOW)
 };
 
 static const struct drm_driver amdgpu_kms_driver = {
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ualink.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ualink.c
index 402d8941fb045..63374c6b9ebd5 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ualink.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ualink.c
@@ -3963,6 +3963,50 @@ int amdgpu_ualink_export_handle(struct drm_device *dev, struct drm_file *filp,
 	return r;
 }
 
+int amdgpu_gem_ualink_handle_ioctl(struct drm_device *dev, void *data,
+				   struct drm_file *filp)
+{
+	union drm_amdgpu_ualink_handle *args = data;
+	struct amdgpu_device *adev = drm_to_adev(dev);
+	struct amdgpu_ualink_handle handle = {};
+	u32 gem_handle;
+	int r, fd = -1;
+
+	if (adev->ualink.info->accel_state !=
+	    AMDGPU_UALINK_ACCEL_STATE_ACTIVE) {
+		dev_err(adev->dev,
+			"ualink device is not in active state in vpod\n");
+		return -EOPNOTSUPP;
+	}
+
+	/* The input and output members of the ioctl argument alias each other.
+	 * Latch every input field before invoking the handlers, and only write
+	 * the output fields afterwards.
+	 */
+	switch (args->in.op) {
+	case DRM_AMDGPU_UALINK_HANDLE_OP_EXPORT:
+		gem_handle = args->in.gem_handle;
+		r = amdgpu_ualink_export_handle(dev, filp, gem_handle, &handle);
+		if (!r) {
+			args->out.export_ualink_handle[0] = handle.handle_lo;
+			args->out.export_ualink_handle[1] = handle.handle_hi;
+		}
+		break;
+	case DRM_AMDGPU_UALINK_HANDLE_OP_IMPORT:
+		handle.handle_lo = args->in.import_ualink_handle[0];
+		handle.handle_hi = args->in.import_ualink_handle[1];
+		r = amdgpu_ualink_import_handle(dev, &handle, &fd);
+		if (!r)
+			args->out.import_dmabuf_handle = fd;
+		break;
+	default:
+		r = -EINVAL;
+		break;
+	}
+
+	return r;
+}
+
 int amdgpu_ualink_manager_start(struct amdgpu_device *adev)
 {
 	int i, r;
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ualink.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ualink.h
index 63710b484c6a5..9908d3a277172 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ualink.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ualink.h
@@ -409,6 +409,8 @@ int amdgpu_ualink_export_handle(struct drm_device *dev, struct drm_file *filp,
 int amdgpu_ualink_import_handle(struct drm_device *dev,
 				const struct amdgpu_ualink_handle *ualink_handle,
 				int *fd_out);
+int amdgpu_gem_ualink_handle_ioctl(struct drm_device *dev, void *data,
+				   struct drm_file *filp);
 void amdgpu_ualink_revoke_exported_memory(struct amdgpu_bo *bo);
 
 int ualink_ip_hw_init(struct amdgpu_ip_block *ip_block);
diff --git a/include/uapi/drm/amdgpu_drm.h b/include/uapi/drm/amdgpu_drm.h
index d6d5402a1e789..0e8115673d8d2 100644
--- a/include/uapi/drm/amdgpu_drm.h
+++ b/include/uapi/drm/amdgpu_drm.h
@@ -59,6 +59,7 @@ extern "C" {
 #define DRM_AMDGPU_USERQ_WAIT		0x18
 #define DRM_AMDGPU_GEM_LIST_HANDLES	0x19
 #define DRM_AMDGPU_PROC_OPTIONS		0x1A
+#define DRM_AMDGPU_UALINK_HANDLE	0x1B
 
 #define DRM_IOCTL_AMDGPU_GEM_CREATE	DRM_IOWR(DRM_COMMAND_BASE + DRM_AMDGPU_GEM_CREATE, union drm_amdgpu_gem_create)
 #define DRM_IOCTL_AMDGPU_GEM_MMAP	DRM_IOWR(DRM_COMMAND_BASE + DRM_AMDGPU_GEM_MMAP, union drm_amdgpu_gem_mmap)
@@ -81,6 +82,7 @@ extern "C" {
 #define DRM_IOCTL_AMDGPU_USERQ_WAIT	DRM_IOWR(DRM_COMMAND_BASE + DRM_AMDGPU_USERQ_WAIT, struct drm_amdgpu_userq_wait)
 #define DRM_IOCTL_AMDGPU_GEM_LIST_HANDLES DRM_IOWR(DRM_COMMAND_BASE + DRM_AMDGPU_GEM_LIST_HANDLES, struct drm_amdgpu_gem_list_handles)
 #define DRM_IOCTL_AMDGPU_PROC_OPTIONS	DRM_IOWR(DRM_COMMAND_BASE + DRM_AMDGPU_PROC_OPTIONS, struct drm_amdgpu_proc_options)
+#define DRM_IOCTL_AMDGPU_UALINK_HANDLE DRM_IOWR(DRM_COMMAND_BASE + DRM_AMDGPU_UALINK_HANDLE, union drm_amdgpu_ualink_handle)
 
 /**
  * DOC: memory domains
@@ -1705,6 +1707,34 @@ struct drm_amdgpu_proc_options {
 	} kfd_sigbus_delay;
 };
 
+#define DRM_AMDGPU_UALINK_HANDLE_OP_EXPORT		0
+#define DRM_AMDGPU_UALINK_HANDLE_OP_IMPORT		1
+
+struct drm_amdgpu_ualink_handle_in {
+	/* Export or import */
+	__u32 op;
+	/* For future use, no flags defined so far */
+	__u32 flags;
+	union {
+		/* GEM handle of the BO to export */
+		__u32 gem_handle;
+		/* UALink handle to import */
+		__u64 import_ualink_handle[2];
+	};
+};
+
+union drm_amdgpu_ualink_handle_out {
+	/* Exported UALink handle */
+	__u64 export_ualink_handle[2];
+	/** DMABuf representing the imported UALink handle */
+	__u32 import_dmabuf_handle;
+};
+
+union drm_amdgpu_ualink_handle {
+	struct drm_amdgpu_ualink_handle_in in;
+	union drm_amdgpu_ualink_handle_out out;
+};
+
 #if defined(__cplusplus)
 }
 #endif
-- 
2.55.0