drm/amdgpu: add interface for editing a foreign process's prioritywip-process-priorities-v1

The AMDGPU_SCHED_OP_PROCESS_PRIORITY_GET/PUT ioctls are used to set the
priority of a different process in the current system.

When all requests are dropped, the foreign process's contexts will be
restored to the priority specified at context creation time.

An fd is used to identify the remote process. This is simpler than
passing a pid number, which is vulnerable to re-use, etc.

This functionality is limited to DRM_MASTER since abuse of this
interface can have a negative impact on the system's performance.

Signed-off-by: Andres Rodriguez <andresx7@gmail.com>

6 files changed, 180 insertions, 19 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/Makefile b/drivers/gpu/drm/amd/amdgpu/Makefile
index b62d9e9cfe6c..e4d3b0776182 100644
--- a/drivers/gpu/drm/amd/amdgpu/Makefile
+++ b/drivers/gpu/drm/amd/amdgpu/Makefile
@@ -25,7 +25,7 @@ amdgpu-y += amdgpu_device.o amdgpu_kms.o \
 	amdgpu_prime.o amdgpu_vm.o amdgpu_ib.o amdgpu_pll.o \
 	amdgpu_ucode.o amdgpu_bo_list.o amdgpu_ctx.o amdgpu_sync.o \
 	amdgpu_gtt_mgr.o amdgpu_vram_mgr.o amdgpu_virt.o amdgpu_atomfirmware.o \
-	amdgpu_queue_mgr.o
+	amdgpu_queue_mgr.o amdgpu_sched.o
 
 # add asic specific block
 amdgpu-$(CONFIG_DRM_AMDGPU_CIK)+= cik.o cik_ih.o kv_smc.o kv_dpm.o \
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
index dca483f4d64e..0f1c1746f4a1 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
@@ -25,6 +25,7 @@
 #include <drm/drmP.h>
 #include <drm/drm_auth.h>
 #include "amdgpu.h"
+#include "amdgpu_sched.h"
 
 static int amdgpu_ctx_priority_permit(struct drm_file *filp,
 				      enum amd_sched_priority priority)
@@ -247,24 +248,6 @@ static int amdgpu_ctx_query(struct amdgpu_device *adev,
 	return 0;
 }
 
-static enum amd_sched_priority amdgpu_to_sched_priority(int amdgpu_priority)
-{
-	switch (amdgpu_priority) {
-	case AMDGPU_CTX_PRIORITY_HIGH_HW:
-		return AMD_SCHED_PRIORITY_HIGH_HW;
-	case AMDGPU_CTX_PRIORITY_HIGH_SW:
-		return AMD_SCHED_PRIORITY_HIGH_SW;
-	case AMDGPU_CTX_PRIORITY_NORMAL:
-		return AMD_SCHED_PRIORITY_NORMAL;
-	case AMDGPU_CTX_PRIORITY_LOW_SW:
-	case AMDGPU_CTX_PRIORITY_LOW_HW:
-		return AMD_SCHED_PRIORITY_LOW;
-	default:
-		WARN(1, "Invalid context priority %d\n", amdgpu_priority);
-		return AMD_SCHED_PRIORITY_INVALID;
-	}
-}
-
 int amdgpu_ctx_ioctl(struct drm_device *dev, void *data,
 		     struct drm_file *filp)
 {
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
index 92e93b34118c..6a33c615e8d9 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
@@ -28,6 +28,7 @@
 #include <drm/drmP.h>
 #include "amdgpu.h"
 #include <drm/amdgpu_drm.h>
+#include "amdgpu_sched.h"
 #include "amdgpu_uvd.h"
 #include "amdgpu_vce.h"
 
@@ -1016,6 +1017,7 @@ const struct drm_ioctl_desc amdgpu_ioctls_kms[] = {
 	DRM_IOCTL_DEF_DRV(AMDGPU_GEM_CREATE, amdgpu_gem_create_ioctl, DRM_AUTH|DRM_RENDER_ALLOW),
 	DRM_IOCTL_DEF_DRV(AMDGPU_CTX, amdgpu_ctx_ioctl, DRM_AUTH|DRM_RENDER_ALLOW),
 	DRM_IOCTL_DEF_DRV(AMDGPU_VM, amdgpu_vm_ioctl, DRM_AUTH|DRM_RENDER_ALLOW),
+	DRM_IOCTL_DEF_DRV(AMDGPU_SCHED, amdgpu_sched_ioctl, DRM_MASTER),
 	DRM_IOCTL_DEF_DRV(AMDGPU_BO_LIST, amdgpu_bo_list_ioctl, DRM_AUTH|DRM_RENDER_ALLOW),
 	/* KMS */
 	DRM_IOCTL_DEF_DRV(AMDGPU_GEM_MMAP, amdgpu_gem_mmap_ioctl, DRM_AUTH|DRM_RENDER_ALLOW),
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_sched.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_sched.c
new file mode 100644
index 000000000000..eacce6fdb1da
--- /dev/null
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_sched.c
@@ -0,0 +1,117 @@
+/*
+ * Copyright 2017 Valve Corporation
+ *
+ * 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.
+ *
+ * Authors: Andres Rodriguez <andresx7@gmail.com>
+ */
+
+#include <linux/fdtable.h>
+#include <linux/pid.h>
+#include <drm/amdgpu_drm.h>
+#include "amdgpu.h"
+
+#include "amdgpu_vm.h"
+
+enum amd_sched_priority amdgpu_to_sched_priority(int amdgpu_priority)
+{
+	switch (amdgpu_priority) {
+	case AMDGPU_CTX_PRIORITY_HIGH_HW:
+		return AMD_SCHED_PRIORITY_HIGH_HW;
+	case AMDGPU_CTX_PRIORITY_HIGH_SW:
+		return AMD_SCHED_PRIORITY_HIGH_SW;
+	case AMDGPU_CTX_PRIORITY_NORMAL:
+		return AMD_SCHED_PRIORITY_NORMAL;
+	case AMDGPU_CTX_PRIORITY_LOW_SW:
+	case AMDGPU_CTX_PRIORITY_LOW_HW:
+		return AMD_SCHED_PRIORITY_LOW;
+	default:
+		WARN(1, "Invalid context priority %d\n", amdgpu_priority);
+		return AMD_SCHED_PRIORITY_INVALID;
+	}
+}
+
+static int amdgpu_sched_process_priority_ref(struct amdgpu_device *adev,
+					     int fd,
+					     enum amd_sched_priority priority,
+					     bool acquire)
+{
+	struct file *filp = fcheck(fd);
+	struct drm_file *file;
+	struct pid *pid;
+	struct amdgpu_fpriv *fpriv;
+	struct amdgpu_ctx *ctx;
+	uint32_t id;
+
+	if (!filp)
+		return -EINVAL;
+
+	pid = get_pid(((struct drm_file *)filp->private_data)->pid);
+
+	mutex_lock(&adev->ddev->filelist_mutex);
+	list_for_each_entry(file, &adev->ddev->filelist, lhead) {
+		if (file->pid != pid)
+			continue;
+
+		fpriv = file->driver_priv;
+		idr_for_each_entry(&fpriv->ctx_mgr.ctx_handles, ctx, id)
+			if (acquire)
+				amdgpu_ctx_priority_get(ctx, priority);
+			else
+				amdgpu_ctx_priority_put(ctx, priority);
+	}
+	mutex_unlock(&adev->ddev->filelist_mutex);
+
+	put_pid(pid);
+
+	return 0;
+}
+
+int amdgpu_sched_ioctl(struct drm_device *dev, void *data,
+		       struct drm_file *filp)
+{
+	union drm_amdgpu_sched *args = data;
+	struct amdgpu_device *adev = dev->dev_private;
+	enum amd_sched_priority priority;
+	int r;
+
+	priority = amdgpu_to_sched_priority(args->in.priority);
+	if (args->in.reserved || priority == AMD_SCHED_PRIORITY_INVALID)
+		return -EINVAL;
+
+	switch (args->in.op) {
+	case AMDGPU_SCHED_OP_PROCESS_PRIORITY_GET:
+		r = amdgpu_sched_process_priority_ref(adev,
+						      args->in.fd,
+						      priority,
+						      true);
+		break;
+	case AMDGPU_SCHED_OP_PROCESS_PRIORITY_PUT:
+		r = amdgpu_sched_process_priority_ref(adev,
+						      args->in.fd,
+						      priority,
+						      false);
+		break;
+	default:
+		r = -EINVAL;
+		break;
+	}
+
+	return r;
+}
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_sched.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_sched.h
new file mode 100644
index 000000000000..b28c067d3822
--- /dev/null
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_sched.h
@@ -0,0 +1,34 @@
+/*
+ * Copyright 2017 Valve Corporation
+ *
+ * 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.
+ *
+ * Authors: Andres Rodriguez <andresx7@gmail.com>
+ */
+
+#ifndef __AMDGPU_SCHED_H__
+#define __AMDGPU_SCHED_H__
+
+#include <drm/drmP.h>
+
+enum amd_sched_priority amdgpu_to_sched_priority(int amdgpu_priority);
+int amdgpu_sched_ioctl(struct drm_device *dev, void *data,
+		       struct drm_file *filp);
+
+#endif // __AMDGPU_SCHED_H__
diff --git a/include/uapi/drm/amdgpu_drm.h b/include/uapi/drm/amdgpu_drm.h
index 590fc2aaf3ff..99eb94653765 100644
--- a/include/uapi/drm/amdgpu_drm.h
+++ b/include/uapi/drm/amdgpu_drm.h
@@ -52,6 +52,7 @@ extern "C" {
 #define DRM_AMDGPU_GEM_USERPTR		0x11
 #define DRM_AMDGPU_WAIT_FENCES		0x12
 #define DRM_AMDGPU_VM			0x13
+#define DRM_AMDGPU_SCHED		0x14
 
 #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)
@@ -67,6 +68,7 @@ extern "C" {
 #define DRM_IOCTL_AMDGPU_GEM_USERPTR	DRM_IOWR(DRM_COMMAND_BASE + DRM_AMDGPU_GEM_USERPTR, struct drm_amdgpu_gem_userptr)
 #define DRM_IOCTL_AMDGPU_WAIT_FENCES	DRM_IOWR(DRM_COMMAND_BASE + DRM_AMDGPU_WAIT_FENCES, union drm_amdgpu_wait_fences)
 #define DRM_IOCTL_AMDGPU_VM		DRM_IOWR(DRM_COMMAND_BASE + DRM_AMDGPU_VM, union drm_amdgpu_vm)
+#define DRM_IOCTL_AMDGPU_SCHED		DRM_IOWR(DRM_COMMAND_BASE + DRM_AMDGPU_SCHED, union drm_amdgpu_sched)
 
 #define AMDGPU_GEM_DOMAIN_CPU		0x1
 #define AMDGPU_GEM_DOMAIN_GTT		0x2
@@ -220,6 +222,29 @@ union drm_amdgpu_vm {
 	struct drm_amdgpu_vm_out out;
 };
 
+/* sched ioctl */
+#define AMDGPU_SCHED_OP_PROCESS_PRIORITY_GET	1
+#define AMDGPU_SCHED_OP_PROCESS_PRIORITY_PUT	2
+
+struct drm_amdgpu_sched_in {
+	/* AMDGPU_SCHED_OP_* */
+	__u32	op;
+	__u32	fd;
+	__s32	priority;
+	/* For future use */
+	__u32	reserved;
+};
+
+struct drm_amdgpu_sched_out {
+	/* For future use */
+	__u64	reserved;
+};
+
+union drm_amdgpu_sched {
+	struct drm_amdgpu_sched_in in;
+	struct drm_amdgpu_sched_out out;
+};
+
 /*
  * This is not a reliable API and you should expect it to fail for any
  * number of reasons and have fallback path that do not use userptr to