Add virtio gpu driver.

This patch adds a kms driver for the virtio gpu.  The xorg modesetting
driver can handle the device just fine, the framebuffer for fbcon is
there too.

Qemu patches for the host side are under review currently.

The pci version of the device comes in two variants: with and without
vga compatibility.  The former has a extra memory bar for the vga
framebuffer, the later is a pure virtio device.  The only concern for
this driver is that in the virtio-vga case we have to kick out the
firmware framebuffer.

Initial revision has only 2d support, 3d (virgl) support requires
some more work on the qemu side and will be added later.

Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 119 insertions, 0 deletions

diff --git a/drivers/gpu/drm/virtio/virtgpu_fence.c b/drivers/gpu/drm/virtio/virtgpu_fence.c
new file mode 100644
index 000000000000..1da632631dac
--- /dev/null
+++ b/drivers/gpu/drm/virtio/virtgpu_fence.c
@@ -0,0 +1,119 @@
+/*
+ * Copyright (C) 2015 Red Hat, Inc.
+ * All Rights Reserved.
+ *
+ * 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 (including the
+ * next paragraph) 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 OWNER(S) AND/OR ITS SUPPLIERS 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.
+ */
+
+#include <drm/drmP.h>
+#include "virtgpu_drv.h"
+
+static const char *virtio_get_driver_name(struct fence *f)
+{
+	return "virtio_gpu";
+}
+
+static const char *virtio_get_timeline_name(struct fence *f)
+{
+	return "controlq";
+}
+
+static bool virtio_enable_signaling(struct fence *f)
+{
+	return true;
+}
+
+static bool virtio_signaled(struct fence *f)
+{
+	struct virtio_gpu_fence *fence = to_virtio_fence(f);
+
+	if (atomic64_read(&fence->drv->last_seq) >= fence->seq)
+		return true;
+	return false;
+}
+
+static void virtio_fence_value_str(struct fence *f, char *str, int size)
+{
+	struct virtio_gpu_fence *fence = to_virtio_fence(f);
+
+	snprintf(str, size, "%llu", fence->seq);
+}
+
+static void virtio_timeline_value_str(struct fence *f, char *str, int size)
+{
+	struct virtio_gpu_fence *fence = to_virtio_fence(f);
+
+	snprintf(str, size, "%lu", atomic64_read(&fence->drv->last_seq));
+}
+
+static const struct fence_ops virtio_fence_ops = {
+	.get_driver_name     = virtio_get_driver_name,
+	.get_timeline_name   = virtio_get_timeline_name,
+	.enable_signaling    = virtio_enable_signaling,
+	.signaled            = virtio_signaled,
+	.wait                = fence_default_wait,
+	.fence_value_str     = virtio_fence_value_str,
+	.timeline_value_str  = virtio_timeline_value_str,
+};
+
+int virtio_gpu_fence_emit(struct virtio_gpu_device *vgdev,
+			  struct virtio_gpu_ctrl_hdr *cmd_hdr,
+			  struct virtio_gpu_fence **fence)
+{
+	struct virtio_gpu_fence_driver *drv = &vgdev->fence_drv;
+	unsigned long irq_flags;
+
+	*fence = kmalloc(sizeof(struct virtio_gpu_fence), GFP_KERNEL);
+	if ((*fence) == NULL)
+		return -ENOMEM;
+
+	spin_lock_irqsave(&drv->lock, irq_flags);
+	(*fence)->drv = drv;
+	(*fence)->seq = ++drv->sync_seq;
+	fence_init(&(*fence)->f, &virtio_fence_ops, &drv->lock,
+		   0, (*fence)->seq);
+	fence_get(&(*fence)->f);
+	list_add_tail(&(*fence)->node, &drv->fences);
+	spin_unlock_irqrestore(&drv->lock, irq_flags);
+
+	cmd_hdr->flags |= cpu_to_le32(VIRTIO_GPU_FLAG_FENCE);
+	cmd_hdr->fence_id = cpu_to_le64((*fence)->seq);
+	return 0;
+}
+
+void virtio_gpu_fence_event_process(struct virtio_gpu_device *vgdev,
+				    u64 last_seq)
+{
+	struct virtio_gpu_fence_driver *drv = &vgdev->fence_drv;
+	struct virtio_gpu_fence *fence, *tmp;
+	unsigned long irq_flags;
+
+	spin_lock_irqsave(&drv->lock, irq_flags);
+	atomic64_set(&vgdev->fence_drv.last_seq, last_seq);
+	list_for_each_entry_safe(fence, tmp, &drv->fences, node) {
+		if (last_seq < fence->seq)
+			continue;
+		fence_signal_locked(&fence->f);
+		list_del(&fence->node);
+		fence_put(&fence->f);
+	}
+	spin_unlock_irqrestore(&drv->lock, irq_flags);
+}