drm/kms: driver for virtual cirrus under qemu

This is the initial driver for emulated cirrus GPU found in qemu.
This driver only supports the emulated GPU and doesn't attempt
to bind to any real cirrus GPUs.

This driver is intended to be used with xf86-video-modesetting in userspace.
It requires at least version 0.3.0

This follow the same design as ast and mgag200, and is based on work
done by Matthew Garrett previously.

This GPU has no hw cursor, and it can't scanout 32-bpp, only packed 24-bpp.
i.e. it sucks.

Reviewed-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 335 insertions, 0 deletions

diff --git a/drivers/gpu/drm/cirrus/cirrus_main.c b/drivers/gpu/drm/cirrus/cirrus_main.c
new file mode 100644
index 00000000000..e3c12257841
--- /dev/null
+++ b/drivers/gpu/drm/cirrus/cirrus_main.c
@@ -0,0 +1,335 @@
+/*
+ * Copyright 2012 Red Hat
+ *
+ * This file is subject to the terms and conditions of the GNU General
+ * Public License version 2. See the file COPYING in the main
+ * directory of this archive for more details.
+ *
+ * Authors: Matthew Garrett
+ *          Dave Airlie
+ */
+#include "drmP.h"
+#include "drm.h"
+#include "drm_crtc_helper.h"
+
+#include "cirrus_drv.h"
+
+
+static void cirrus_user_framebuffer_destroy(struct drm_framebuffer *fb)
+{
+	struct cirrus_framebuffer *cirrus_fb = to_cirrus_framebuffer(fb);
+	if (cirrus_fb->obj)
+		drm_gem_object_unreference_unlocked(cirrus_fb->obj);
+	drm_framebuffer_cleanup(fb);
+	kfree(fb);
+}
+
+static int cirrus_user_framebuffer_create_handle(struct drm_framebuffer *fb,
+						 struct drm_file *file_priv,
+						 unsigned int *handle)
+{
+	return 0;
+}
+
+static const struct drm_framebuffer_funcs cirrus_fb_funcs = {
+	.destroy = cirrus_user_framebuffer_destroy,
+	.create_handle = cirrus_user_framebuffer_create_handle,
+};
+
+int cirrus_framebuffer_init(struct drm_device *dev,
+			    struct cirrus_framebuffer *gfb,
+			    struct drm_mode_fb_cmd2 *mode_cmd,
+			    struct drm_gem_object *obj)
+{
+	int ret;
+
+	ret = drm_framebuffer_init(dev, &gfb->base, &cirrus_fb_funcs);
+	if (ret) {
+		DRM_ERROR("drm_framebuffer_init failed: %d\n", ret);
+		return ret;
+	}
+	drm_helper_mode_fill_fb_struct(&gfb->base, mode_cmd);
+	gfb->obj = obj;
+	return 0;
+}
+
+static struct drm_framebuffer *
+cirrus_user_framebuffer_create(struct drm_device *dev,
+			       struct drm_file *filp,
+			       struct drm_mode_fb_cmd2 *mode_cmd)
+{
+	struct drm_gem_object *obj;
+	struct cirrus_framebuffer *cirrus_fb;
+	int ret;
+	u32 bpp, depth;
+
+	drm_fb_get_bpp_depth(mode_cmd->pixel_format, &depth, &bpp);
+	/* cirrus can't handle > 24bpp framebuffers at all */
+	if (bpp > 24)
+		return ERR_PTR(-EINVAL);
+
+	obj = drm_gem_object_lookup(dev, filp, mode_cmd->handles[0]);
+	if (obj == NULL)
+		return ERR_PTR(-ENOENT);
+
+	cirrus_fb = kzalloc(sizeof(*cirrus_fb), GFP_KERNEL);
+	if (!cirrus_fb) {
+		drm_gem_object_unreference_unlocked(obj);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	ret = cirrus_framebuffer_init(dev, cirrus_fb, mode_cmd, obj);
+	if (ret) {
+		drm_gem_object_unreference_unlocked(obj);
+		kfree(cirrus_fb);
+		return ERR_PTR(ret);
+	}
+	return &cirrus_fb->base;
+}
+
+static const struct drm_mode_config_funcs cirrus_mode_funcs = {
+	.fb_create = cirrus_user_framebuffer_create,
+};
+
+/* Unmap the framebuffer from the core and release the memory */
+static void cirrus_vram_fini(struct cirrus_device *cdev)
+{
+	iounmap(cdev->rmmio);
+	cdev->rmmio = NULL;
+	if (cdev->mc.vram_base)
+		release_mem_region(cdev->mc.vram_base, cdev->mc.vram_size);
+}
+
+/* Map the framebuffer from the card and configure the core */
+static int cirrus_vram_init(struct cirrus_device *cdev)
+{
+	/* BAR 0 is VRAM */
+	cdev->mc.vram_base = pci_resource_start(cdev->dev->pdev, 0);
+	/* We have 4MB of VRAM */
+	cdev->mc.vram_size = 4 * 1024 * 1024;
+
+	if (!request_mem_region(cdev->mc.vram_base, cdev->mc.vram_size,
+				"cirrusdrmfb_vram")) {
+		DRM_ERROR("can't reserve VRAM\n");
+		return -ENXIO;
+	}
+
+	return 0;
+}
+
+/*
+ * Our emulated hardware has two sets of memory. One is video RAM and can
+ * simply be used as a linear framebuffer - the other provides mmio access
+ * to the display registers. The latter can also be accessed via IO port
+ * access, but we map the range and use mmio to program them instead
+ */
+
+int cirrus_device_init(struct cirrus_device *cdev,
+		       struct drm_device *ddev,
+		       struct pci_dev *pdev, uint32_t flags)
+{
+	int ret;
+
+	cdev->dev = ddev;
+	cdev->flags = flags;
+
+	/* Hardcode the number of CRTCs to 1 */
+	cdev->num_crtc = 1;
+
+	/* BAR 0 is the framebuffer, BAR 1 contains registers */
+	cdev->rmmio_base = pci_resource_start(cdev->dev->pdev, 1);
+	cdev->rmmio_size = pci_resource_len(cdev->dev->pdev, 1);
+
+	if (!request_mem_region(cdev->rmmio_base, cdev->rmmio_size,
+				"cirrusdrmfb_mmio")) {
+		DRM_ERROR("can't reserve mmio registers\n");
+		return -ENOMEM;
+	}
+
+	cdev->rmmio = ioremap(cdev->rmmio_base, cdev->rmmio_size);
+
+	if (cdev->rmmio == NULL)
+		return -ENOMEM;
+
+	ret = cirrus_vram_init(cdev);
+	if (ret) {
+		release_mem_region(cdev->rmmio_base, cdev->rmmio_size);
+		return ret;
+	}
+
+	return 0;
+}
+
+void cirrus_device_fini(struct cirrus_device *cdev)
+{
+	release_mem_region(cdev->rmmio_base, cdev->rmmio_size);
+	cirrus_vram_fini(cdev);
+}
+
+/*
+ * Functions here will be called by the core once it's bound the driver to
+ * a PCI device
+ */
+
+int cirrus_driver_load(struct drm_device *dev, unsigned long flags)
+{
+	struct cirrus_device *cdev;
+	int r;
+
+	cdev = kzalloc(sizeof(struct cirrus_device), GFP_KERNEL);
+	if (cdev == NULL)
+		return -ENOMEM;
+	dev->dev_private = (void *)cdev;
+
+	r = cirrus_device_init(cdev, dev, dev->pdev, flags);
+	if (r) {
+		dev_err(&dev->pdev->dev, "Fatal error during GPU init: %d\n", r);
+		goto out;
+	}
+
+	r = cirrus_mm_init(cdev);
+	if (r)
+		dev_err(&dev->pdev->dev, "fatal err on mm init\n");
+
+	r = cirrus_modeset_init(cdev);
+	if (r)
+		dev_err(&dev->pdev->dev, "Fatal error during modeset init: %d\n", r);
+
+	dev->mode_config.funcs = (void *)&cirrus_mode_funcs;
+out:
+	if (r)
+		cirrus_driver_unload(dev);
+	return r;
+}
+
+int cirrus_driver_unload(struct drm_device *dev)
+{
+	struct cirrus_device *cdev = dev->dev_private;
+
+	if (cdev == NULL)
+		return 0;
+	cirrus_modeset_fini(cdev);
+	cirrus_mm_fini(cdev);
+	cirrus_device_fini(cdev);
+	kfree(cdev);
+	dev->dev_private = NULL;
+	return 0;
+}
+
+int cirrus_gem_create(struct drm_device *dev,
+		   u32 size, bool iskernel,
+		   struct drm_gem_object **obj)
+{
+	struct cirrus_bo *cirrusbo;
+	int ret;
+
+	*obj = NULL;
+
+	size = roundup(size, PAGE_SIZE);
+	if (size == 0)
+		return -EINVAL;
+
+	ret = cirrus_bo_create(dev, size, 0, 0, &cirrusbo);
+	if (ret) {
+		if (ret != -ERESTARTSYS)
+			DRM_ERROR("failed to allocate GEM object\n");
+		return ret;
+	}
+	*obj = &cirrusbo->gem;
+	return 0;
+}
+
+int cirrus_dumb_create(struct drm_file *file,
+		    struct drm_device *dev,
+		    struct drm_mode_create_dumb *args)
+{
+	int ret;
+	struct drm_gem_object *gobj;
+	u32 handle;
+
+	args->pitch = args->width * ((args->bpp + 7) / 8);
+	args->size = args->pitch * args->height;
+
+	ret = cirrus_gem_create(dev, args->size, false,
+			     &gobj);
+	if (ret)
+		return ret;
+
+	ret = drm_gem_handle_create(file, gobj, &handle);
+	drm_gem_object_unreference_unlocked(gobj);
+	if (ret)
+		return ret;
+
+	args->handle = handle;
+	return 0;
+}
+
+int cirrus_dumb_destroy(struct drm_file *file,
+		     struct drm_device *dev,
+		     uint32_t handle)
+{
+	return drm_gem_handle_delete(file, handle);
+}
+
+int cirrus_gem_init_object(struct drm_gem_object *obj)
+{
+	BUG();
+	return 0;
+}
+
+void cirrus_bo_unref(struct cirrus_bo **bo)
+{
+	struct ttm_buffer_object *tbo;
+
+	if ((*bo) == NULL)
+		return;
+
+	tbo = &((*bo)->bo);
+	ttm_bo_unref(&tbo);
+	if (tbo == NULL)
+		*bo = NULL;
+
+}
+
+void cirrus_gem_free_object(struct drm_gem_object *obj)
+{
+	struct cirrus_bo *cirrus_bo = gem_to_cirrus_bo(obj);
+
+	if (!cirrus_bo)
+		return;
+	cirrus_bo_unref(&cirrus_bo);
+}
+
+
+static inline u64 cirrus_bo_mmap_offset(struct cirrus_bo *bo)
+{
+	return bo->bo.addr_space_offset;
+}
+
+int
+cirrus_dumb_mmap_offset(struct drm_file *file,
+		     struct drm_device *dev,
+		     uint32_t handle,
+		     uint64_t *offset)
+{
+	struct drm_gem_object *obj;
+	int ret;
+	struct cirrus_bo *bo;
+
+	mutex_lock(&dev->struct_mutex);
+	obj = drm_gem_object_lookup(dev, file, handle);
+	if (obj == NULL) {
+		ret = -ENOENT;
+		goto out_unlock;
+	}
+
+	bo = gem_to_cirrus_bo(obj);
+	*offset = cirrus_bo_mmap_offset(bo);
+
+	drm_gem_object_unreference(obj);
+	ret = 0;
+out_unlock:
+	mutex_unlock(&dev->struct_mutex);
+	return ret;
+
+}