drm/bochs: new driver

DRM driver for (virtual) vga cards using the bochs dispi
interface, such as the qemu standard vga (qemu -vga std).

Don't bother supporting anything but 32bpp for now, even
though the virtual hardware is able to do that.

Known issue: mmap(/dev/fb0) doesn't work.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/Kconfig

@@ -192,6 +192,8 @@ source "drivers/gpu/drm/tilcdc/Kconfig"
 
 source "drivers/gpu/drm/qxl/Kconfig"
 
+source "drivers/gpu/drm/bochs/Kconfig"
+
 source "drivers/gpu/drm/msm/Kconfig"
 
 source "drivers/gpu/drm/tegra/Kconfig"

drivers/gpu/drm/Makefile

@@ -58,6 +58,7 @@ obj-$(CONFIG_DRM_SHMOBILE) +=shmobile/
 obj-$(CONFIG_DRM_OMAP)	+= omapdrm/
 obj-$(CONFIG_DRM_TILCDC)	+= tilcdc/
 obj-$(CONFIG_DRM_QXL) += qxl/
+obj-$(CONFIG_DRM_BOCHS) += bochs/
 obj-$(CONFIG_DRM_MSM) += msm/
 obj-$(CONFIG_DRM_TEGRA) += tegra/
 obj-y			+= i2c/

drivers/gpu/drm/bochs/Kconfig

+config DRM_BOCHS
+	tristate "DRM Support for bochs dispi vga interface (qemu stdvga)"
+	depends on DRM && PCI
+	select DRM_KMS_HELPER
+	select FB_SYS_FILLRECT
+	select FB_SYS_COPYAREA
+	select FB_SYS_IMAGEBLIT
+	select DRM_TTM
+	help
+	  Choose this option for qemu.
+	  If M is selected the module will be called bochs-drm.

drivers/gpu/drm/bochs/Makefile

+ccflags-y := -Iinclude/drm
+bochs-drm-y := bochs_drv.o bochs_mm.o bochs_kms.o bochs_fbdev.o bochs_hw.o
+
+obj-$(CONFIG_DRM_BOCHS)	+= bochs-drm.o

drivers/gpu/drm/bochs/bochs.h

+#include <linux/io.h>
+#include <linux/fb.h>
+
+#include <drm/drmP.h>
+#include <drm/drm_crtc.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_fb_helper.h>
+
+#include <ttm/ttm_bo_driver.h>
+#include <ttm/ttm_page_alloc.h>
+
+/* ---------------------------------------------------------------------- */
+
+#define VBE_DISPI_IOPORT_INDEX           0x01CE
+#define VBE_DISPI_IOPORT_DATA            0x01CF
+
+#define VBE_DISPI_INDEX_ID               0x0
+#define VBE_DISPI_INDEX_XRES             0x1
+#define VBE_DISPI_INDEX_YRES             0x2
+#define VBE_DISPI_INDEX_BPP              0x3
+#define VBE_DISPI_INDEX_ENABLE           0x4
+#define VBE_DISPI_INDEX_BANK             0x5
+#define VBE_DISPI_INDEX_VIRT_WIDTH       0x6
+#define VBE_DISPI_INDEX_VIRT_HEIGHT      0x7
+#define VBE_DISPI_INDEX_X_OFFSET         0x8
+#define VBE_DISPI_INDEX_Y_OFFSET         0x9
+#define VBE_DISPI_INDEX_VIDEO_MEMORY_64K 0xa
+
+#define VBE_DISPI_ID0                    0xB0C0
+#define VBE_DISPI_ID1                    0xB0C1
+#define VBE_DISPI_ID2                    0xB0C2
+#define VBE_DISPI_ID3                    0xB0C3
+#define VBE_DISPI_ID4                    0xB0C4
+#define VBE_DISPI_ID5                    0xB0C5
+
+#define VBE_DISPI_DISABLED               0x00
+#define VBE_DISPI_ENABLED                0x01
+#define VBE_DISPI_GETCAPS                0x02
+#define VBE_DISPI_8BIT_DAC               0x20
+#define VBE_DISPI_LFB_ENABLED            0x40
+#define VBE_DISPI_NOCLEARMEM             0x80
+
+/* ---------------------------------------------------------------------- */
+
+enum bochs_types {
+	BOCHS_QEMU_STDVGA,
+	BOCHS_UNKNOWN,
+};
+
+struct bochs_framebuffer {
+	struct drm_framebuffer base;
+	struct drm_gem_object *obj;
+};
+
+struct bochs_device {
+	/* hw */
+	void __iomem   *mmio;
+	int            ioports;
+	void __iomem   *fb_map;
+	unsigned long  fb_base;
+	unsigned long  fb_size;
+
+	/* mode */
+	u16 xres;
+	u16 yres;
+	u16 yres_virtual;
+	u32 stride;
+	u32 bpp;
+
+	/* drm */
+	struct drm_device  *dev;
+	struct drm_crtc crtc;
+	struct drm_encoder encoder;
+	struct drm_connector connector;
+	bool mode_config_initialized;
+
+	/* ttm */
+	struct {
+		struct drm_global_reference mem_global_ref;
+		struct ttm_bo_global_ref bo_global_ref;
+		struct ttm_bo_device bdev;
+		bool initialized;
+	} ttm;
+
+	/* fbdev */
+	struct {
+		struct bochs_framebuffer gfb;
+		struct drm_fb_helper helper;
+		int size;
+		int x1, y1, x2, y2; /* dirty rect */
+		spinlock_t dirty_lock;
+		bool initialized;
+	} fb;
+};
+
+#define to_bochs_framebuffer(x) container_of(x, struct bochs_framebuffer, base)
+
+struct bochs_bo {
+	struct ttm_buffer_object bo;
+	struct ttm_placement placement;
+	struct ttm_bo_kmap_obj kmap;
+	struct drm_gem_object gem;
+	u32 placements[3];
+	int pin_count;
+};
+
+static inline struct bochs_bo *bochs_bo(struct ttm_buffer_object *bo)
+{
+	return container_of(bo, struct bochs_bo, bo);
+}
+
+static inline struct bochs_bo *gem_to_bochs_bo(struct drm_gem_object *gem)
+{
+	return container_of(gem, struct bochs_bo, gem);
+}
+
+#define DRM_FILE_PAGE_OFFSET (0x100000000ULL >> PAGE_SHIFT)
+
+static inline u64 bochs_bo_mmap_offset(struct bochs_bo *bo)
+{
+	return drm_vma_node_offset_addr(&bo->bo.vma_node);
+}
+
+/* ---------------------------------------------------------------------- */
+
+/* bochs_hw.c */
+int bochs_hw_init(struct drm_device *dev, uint32_t flags);
+void bochs_hw_fini(struct drm_device *dev);
+
+void bochs_hw_setmode(struct bochs_device *bochs,
+		      struct drm_display_mode *mode);
+void bochs_hw_setbase(struct bochs_device *bochs,
+		      int x, int y, u64 addr);
+
+/* bochs_mm.c */
+int bochs_mm_init(struct bochs_device *bochs);
+void bochs_mm_fini(struct bochs_device *bochs);
+int bochs_mmap(struct file *filp, struct vm_area_struct *vma);
+
+int bochs_gem_create(struct drm_device *dev, u32 size, bool iskernel,
+		     struct drm_gem_object **obj);
+int bochs_gem_init_object(struct drm_gem_object *obj);
+void bochs_gem_free_object(struct drm_gem_object *obj);
+int bochs_dumb_create(struct drm_file *file, struct drm_device *dev,
+		      struct drm_mode_create_dumb *args);
+int bochs_dumb_mmap_offset(struct drm_file *file, struct drm_device *dev,
+			   uint32_t handle, uint64_t *offset);
+
+int bochs_framebuffer_init(struct drm_device *dev,
+			   struct bochs_framebuffer *gfb,
+			   struct drm_mode_fb_cmd2 *mode_cmd,
+			   struct drm_gem_object *obj);
+int bochs_bo_pin(struct bochs_bo *bo, u32 pl_flag, u64 *gpu_addr);
+int bochs_bo_unpin(struct bochs_bo *bo);
+
+extern const struct drm_mode_config_funcs bochs_mode_funcs;
+
+/* bochs_kms.c */
+int bochs_kms_init(struct bochs_device *bochs);
+void bochs_kms_fini(struct bochs_device *bochs);
+
+/* bochs_fbdev.c */
+int bochs_fbdev_init(struct bochs_device *bochs);
+void bochs_fbdev_fini(struct bochs_device *bochs);

drivers/gpu/drm/bochs/bochs_drv.c

+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+#include "bochs.h"
+
+static bool enable_fbdev = true;
+module_param_named(fbdev, enable_fbdev, bool, 0444);
+MODULE_PARM_DESC(fbdev, "register fbdev device");
+
+/* ---------------------------------------------------------------------- */
+/* drm interface                                                          */
+
+static int bochs_unload(struct drm_device *dev)
+{
+	struct bochs_device *bochs = dev->dev_private;
+
+	bochs_fbdev_fini(bochs);
+	bochs_kms_fini(bochs);
+	bochs_mm_fini(bochs);
+	bochs_hw_fini(dev);
+	kfree(bochs);
+	dev->dev_private = NULL;
+	return 0;
+}
+
+static int bochs_load(struct drm_device *dev, unsigned long flags)
+{
+	struct bochs_device *bochs;
+	int ret;
+
+	bochs = kzalloc(sizeof(*bochs), GFP_KERNEL);
+	if (bochs == NULL)
+		return -ENOMEM;
+	dev->dev_private = bochs;
+	bochs->dev = dev;
+
+	ret = bochs_hw_init(dev, flags);
+	if (ret)
+		goto err;
+
+	ret = bochs_mm_init(bochs);
+	if (ret)
+		goto err;
+
+	ret = bochs_kms_init(bochs);
+	if (ret)
+		goto err;
+
+	if (enable_fbdev)
+		bochs_fbdev_init(bochs);
+
+	return 0;
+
+err:
+	bochs_unload(dev);
+	return ret;
+}
+
+static const struct file_operations bochs_fops = {
+	.owner		= THIS_MODULE,
+	.open		= drm_open,
+	.release	= drm_release,
+	.unlocked_ioctl	= drm_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl	= drm_compat_ioctl,
+#endif
+	.poll		= drm_poll,
+	.read		= drm_read,
+	.llseek		= no_llseek,
+	.mmap           = bochs_mmap,
+};
+
+static struct drm_driver bochs_driver = {
+	.driver_features	= DRIVER_GEM | DRIVER_MODESET,
+	.load			= bochs_load,
+	.unload			= bochs_unload,
+	.fops			= &bochs_fops,
+	.name			= "bochs-drm",
+	.desc			= "bochs dispi vga interface (qemu stdvga)",
+	.date			= "20130925",
+	.major			= 1,
+	.minor			= 0,
+	.gem_free_object        = bochs_gem_free_object,
+	.dumb_create            = bochs_dumb_create,
+	.dumb_map_offset        = bochs_dumb_mmap_offset,
+	.dumb_destroy           = drm_gem_dumb_destroy,
+};
+
+/* ---------------------------------------------------------------------- */
+/* pci interface                                                          */
+
+static int bochs_kick_out_firmware_fb(struct pci_dev *pdev)
+{
+	struct apertures_struct *ap;
+
+	ap = alloc_apertures(1);
+	if (!ap)
+		return -ENOMEM;
+
+	ap->ranges[0].base = pci_resource_start(pdev, 0);
+	ap->ranges[0].size = pci_resource_len(pdev, 0);
+	remove_conflicting_framebuffers(ap, "bochsdrmfb", false);
+	kfree(ap);
+
+	return 0;
+}
+
+static int bochs_pci_probe(struct pci_dev *pdev,
+			   const struct pci_device_id *ent)
+{
+	int ret;
+
+	ret = bochs_kick_out_firmware_fb(pdev);
+	if (ret)
+		return ret;
+
+	return drm_get_pci_dev(pdev, ent, &bochs_driver);
+}
+
+static void bochs_pci_remove(struct pci_dev *pdev)
+{
+	struct drm_device *dev = pci_get_drvdata(pdev);
+
+	drm_put_dev(dev);
+}
+
+static DEFINE_PCI_DEVICE_TABLE(bochs_pci_tbl) = {
+	{
+		.vendor      = 0x1234,
+		.device      = 0x1111,
+		.subvendor   = 0x1af4,
+		.subdevice   = 0x1100,
+		.driver_data = BOCHS_QEMU_STDVGA,
+	},
+	{
+		.vendor      = 0x1234,
+		.device      = 0x1111,
+		.subvendor   = PCI_ANY_ID,
+		.subdevice   = PCI_ANY_ID,
+		.driver_data = BOCHS_UNKNOWN,
+	},
+	{ /* end of list */ }
+};
+
+static struct pci_driver bochs_pci_driver = {
+	.name =		"bochs-drm",
+	.id_table =	bochs_pci_tbl,
+	.probe =	bochs_pci_probe,
+	.remove =	bochs_pci_remove,
+};
+
+/* ---------------------------------------------------------------------- */
+/* module init/exit                                                       */
+
+static int __init bochs_init(void)
+{
+	return drm_pci_init(&bochs_driver, &bochs_pci_driver);
+}
+
+static void __exit bochs_exit(void)
+{
+	drm_pci_exit(&bochs_driver, &bochs_pci_driver);
+}
+
+module_init(bochs_init);
+module_exit(bochs_exit);
+
+MODULE_DEVICE_TABLE(pci, bochs_pci_tbl);
+MODULE_AUTHOR("Gerd Hoffmann <kraxel@redhat.com>");
+MODULE_LICENSE("GPL");

drivers/gpu/drm/bochs/bochs_fbdev.c

+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include "bochs.h"
+
+/* ---------------------------------------------------------------------- */
+
+static struct fb_ops bochsfb_ops = {
+	.owner = THIS_MODULE,
+	.fb_check_var = drm_fb_helper_check_var,
+	.fb_set_par = drm_fb_helper_set_par,
+	.fb_fillrect = sys_fillrect,
+	.fb_copyarea = sys_copyarea,
+	.fb_imageblit = sys_imageblit,
+	.fb_pan_display = drm_fb_helper_pan_display,
+	.fb_blank = drm_fb_helper_blank,
+	.fb_setcmap = drm_fb_helper_setcmap,
+};
+
+static int bochsfb_create_object(struct bochs_device *bochs,
+				 struct drm_mode_fb_cmd2 *mode_cmd,
+				 struct drm_gem_object **gobj_p)
+{
+	struct drm_device *dev = bochs->dev;
+	struct drm_gem_object *gobj;
+	u32 size;
+	int ret = 0;
+
+	size = mode_cmd->pitches[0] * mode_cmd->height;
+	ret = bochs_gem_create(dev, size, true, &gobj);
+	if (ret)
+		return ret;
+
+	*gobj_p = gobj;
+	return ret;
+}
+
+static int bochsfb_create(struct drm_fb_helper *helper,
+			  struct drm_fb_helper_surface_size *sizes)
+{
+	struct bochs_device *bochs =
+		container_of(helper, struct bochs_device, fb.helper);
+	struct drm_device *dev = bochs->dev;
+	struct fb_info *info;
+	struct drm_framebuffer *fb;
+	struct drm_mode_fb_cmd2 mode_cmd;
+	struct device *device = &dev->pdev->dev;
+	struct drm_gem_object *gobj = NULL;
+	struct bochs_bo *bo = NULL;
+	int size, ret;
+
+	if (sizes->surface_bpp != 32)
+		return -EINVAL;
+
+	mode_cmd.width = sizes->surface_width;
+	mode_cmd.height = sizes->surface_height;
+	mode_cmd.pitches[0] = mode_cmd.width * ((sizes->surface_bpp + 7) / 8);
+	mode_cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
+							  sizes->surface_depth);
+	size = mode_cmd.pitches[0] * mode_cmd.height;
+
+	/* alloc, pin & map bo */
+	ret = bochsfb_create_object(bochs, &mode_cmd, &gobj);
+	if (ret) {
+		DRM_ERROR("failed to create fbcon backing object %d\n", ret);
+		return ret;
+	}
+
+	bo = gem_to_bochs_bo(gobj);
+
+	ret = ttm_bo_reserve(&bo->bo, true, false, false, 0);
+	if (ret)
+		return ret;
+
+	ret = bochs_bo_pin(bo, TTM_PL_FLAG_VRAM, NULL);
+	if (ret) {
+		DRM_ERROR("failed to pin fbcon\n");
+		ttm_bo_unreserve(&bo->bo);
+		return ret;
+	}
+
+	ret = ttm_bo_kmap(&bo->bo, 0, bo->bo.num_pages,
+			  &bo->kmap);
+	if (ret) {
+		DRM_ERROR("failed to kmap fbcon\n");
+		ttm_bo_unreserve(&bo->bo);
+		return ret;
+	}
+
+	ttm_bo_unreserve(&bo->bo);
+
+	/* init fb device */
+	info = framebuffer_alloc(0, device);
+	if (info == NULL)
+		return -ENOMEM;
+
+	info->par = &bochs->fb.helper;
+
+	ret = bochs_framebuffer_init(bochs->dev, &bochs->fb.gfb, &mode_cmd, gobj);
+	if (ret)
+		return ret;
+
+	bochs->fb.size = size;
+
+	/* setup helper */
+	fb = &bochs->fb.gfb.base;
+	bochs->fb.helper.fb = fb;
+	bochs->fb.helper.fbdev = info;
+
+	strcpy(info->fix.id, "bochsdrmfb");
+
+	info->flags = FBINFO_DEFAULT;
+	info->fbops = &bochsfb_ops;
+
+	drm_fb_helper_fill_fix(info, fb->pitches[0], fb->depth);
+	drm_fb_helper_fill_var(info, &bochs->fb.helper, sizes->fb_width,
+			       sizes->fb_height);
+
+	info->screen_base = bo->kmap.virtual;
+	info->screen_size = size;
+
+#if 0
+	/* FIXME: get this right for mmap(/dev/fb0) */
+	info->fix.smem_start = bochs_bo_mmap_offset(bo);
+	info->fix.smem_len = size;
+#endif
+
+	ret = fb_alloc_cmap(&info->cmap, 256, 0);
+	if (ret) {
+		DRM_ERROR("%s: can't allocate color map\n", info->fix.id);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static int bochs_fbdev_destroy(struct bochs_device *bochs)
+{
+	struct bochs_framebuffer *gfb = &bochs->fb.gfb;
+	struct fb_info *info;
+
+	DRM_DEBUG_DRIVER("\n");
+
+	if (bochs->fb.helper.fbdev) {
+		info = bochs->fb.helper.fbdev;
+
+		unregister_framebuffer(info);
+		if (info->cmap.len)
+			fb_dealloc_cmap(&info->cmap);
+		framebuffer_release(info);
+	}
+
+	if (gfb->obj) {
+		drm_gem_object_unreference_unlocked(gfb->obj);
+		gfb->obj = NULL;
+	}
+
+	drm_fb_helper_fini(&bochs->fb.helper);
+	drm_framebuffer_unregister_private(&gfb->base);
+	drm_framebuffer_cleanup(&gfb->base);
+
+	return 0;
+}
+
+void bochs_fb_gamma_set(struct drm_crtc *crtc, u16 red, u16 green,
+			u16 blue, int regno)
+{
+}
+
+void bochs_fb_gamma_get(struct drm_crtc *crtc, u16 *red, u16 *green,
+			u16 *blue, int regno)
+{
+	*red   = regno;
+	*green = regno;
+	*blue  = regno;
+}
+
+static struct drm_fb_helper_funcs bochs_fb_helper_funcs = {
+	.gamma_set = bochs_fb_gamma_set,
+	.gamma_get = bochs_fb_gamma_get,
+	.fb_probe = bochsfb_create,
+};
+
+int bochs_fbdev_init(struct bochs_device *bochs)
+{
+	int ret;
+
+	bochs->fb.helper.funcs = &bochs_fb_helper_funcs;
+	spin_lock_init(&bochs->fb.dirty_lock);
+
+	ret = drm_fb_helper_init(bochs->dev, &bochs->fb.helper,
+				 1, 1);
+	if (ret)
+		return ret;
+
+	drm_fb_helper_single_add_all_connectors(&bochs->fb.helper);
+	drm_helper_disable_unused_functions(bochs->dev);
+	drm_fb_helper_initial_config(&bochs->fb.helper, 32);
+
+	bochs->fb.initialized = true;
+	return 0;
+}
+
+void bochs_fbdev_fini(struct bochs_device *bochs)
+{
+	if (!bochs->fb.initialized)
+		return;
+
+	bochs_fbdev_destroy(bochs);
+	bochs->fb.initialized = false;
+}

drivers/gpu/drm/bochs/bochs_hw.c

+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include "bochs.h"
+
+/* ---------------------------------------------------------------------- */
+
+static void bochs_vga_writeb(struct bochs_device *bochs, u16 ioport, u8 val)
+{
+	if (WARN_ON(ioport < 0x3c0 || ioport > 0x3df))
+		return;
+
+	if (bochs->mmio) {
+		int offset = ioport - 0x3c0 + 0x400;
+		writeb(val, bochs->mmio + offset);
+	} else {
+		outb(val, ioport);
+	}
+}
+
+static u16 bochs_dispi_read(struct bochs_device *bochs, u16 reg)
+{
+	u16 ret = 0;
+
+	if (bochs->mmio) {
+		int offset = 0x500 + (reg << 1);
+		ret = readw(bochs->mmio + offset);
+	} else {
+		outw(reg, VBE_DISPI_IOPORT_INDEX);
+		ret = inw(VBE_DISPI_IOPORT_DATA);
+	}
+	return ret;
+}
+
+static void bochs_dispi_write(struct bochs_device *bochs, u16 reg, u16 val)
+{
+	if (bochs->mmio) {
+		int offset = 0x500 + (reg << 1);
+		writew(val, bochs->mmio + offset);
+	} else {
+		outw(reg, VBE_DISPI_IOPORT_INDEX);
+		outw(val, VBE_DISPI_IOPORT_DATA);
+	}
+}
+
+int bochs_hw_init(struct drm_device *dev, uint32_t flags)
+{
+	struct bochs_device *bochs = dev->dev_private;
+	struct pci_dev *pdev = dev->pdev;
+	unsigned long addr, size, mem, ioaddr, iosize;
+	u16 id;
+
+	if (/* (ent->driver_data == BOCHS_QEMU_STDVGA) && */
+	    (pdev->resource[2].flags & IORESOURCE_MEM)) {
+		/* mmio bar with vga and bochs registers present */
+		if (pci_request_region(pdev, 2, "bochs-drm") != 0) {
+			DRM_ERROR("Cannot request mmio region\n");
+			return -EBUSY;
+		}
+		ioaddr = pci_resource_start(pdev, 2);
+		iosize = pci_resource_len(pdev, 2);
+		bochs->mmio = ioremap(ioaddr, iosize);
+		if (bochs->mmio == NULL) {
+			DRM_ERROR("Cannot map mmio region\n");
+			return -ENOMEM;
+		}
+	} else {
+		ioaddr = VBE_DISPI_IOPORT_INDEX;
+		iosize = 2;
+		if (!request_region(ioaddr, iosize, "bochs-drm")) {
+			DRM_ERROR("Cannot request ioports\n");
+			return -EBUSY;
+		}
+		bochs->ioports = 1;
+	}
+
+	id = bochs_dispi_read(bochs, VBE_DISPI_INDEX_ID);
+	mem = bochs_dispi_read(bochs, VBE_DISPI_INDEX_VIDEO_MEMORY_64K)
+		* 64 * 1024;
+	if ((id & 0xfff0) != VBE_DISPI_ID0) {
+		DRM_ERROR("ID mismatch\n");
+		return -ENODEV;
+	}
+
+	if ((pdev->resource[0].flags & IORESOURCE_MEM) == 0)
+		return -ENODEV;
+	addr = pci_resource_start(pdev, 0);
+	size = pci_resource_len(pdev, 0);
+	if (addr == 0)
+		return -ENODEV;
+	if (size != mem) {
+		DRM_ERROR("Size mismatch: pci=%ld, bochs=%ld\n",
+			size, mem);
+		size = min(size, mem);
+	}
+
+	if (pci_request_region(pdev, 0, "bochs-drm") != 0) {
+		DRM_ERROR("Cannot request framebuffer\n");
+		return -EBUSY;
+	}
+
+	bochs->fb_map = ioremap(addr, size);
+	if (bochs->fb_map == NULL) {
+		DRM_ERROR("Cannot map framebuffer\n");
+		return -ENOMEM;
+	}
+	bochs->fb_base = addr;
+	bochs->fb_size = size;
+
+	DRM_INFO("Found bochs VGA, ID 0x%x.\n", id);
+	DRM_INFO("Framebuffer size %ld kB @ 0x%lx, %s @ 0x%lx.\n",
+		 size / 1024, addr,
+		 bochs->ioports ? "ioports" : "mmio",
+		 ioaddr);
+	return 0;
+}
+
+void bochs_hw_fini(struct drm_device *dev)
+{
+	struct bochs_device *bochs = dev->dev_private;
+
+	if (bochs->mmio)
+		iounmap(bochs->mmio);
+	if (bochs->ioports)
+		release_region(VBE_DISPI_IOPORT_INDEX, 2);
+	if (bochs->fb_map)
+		iounmap(bochs->fb_map);
+	pci_release_regions(dev->pdev);
+}
+
+void bochs_hw_setmode(struct bochs_device *bochs,
+		      struct drm_display_mode *mode)
+{
+	bochs->xres = mode->hdisplay;
+	bochs->yres = mode->vdisplay;
+	bochs->bpp = 32;
+	bochs->stride = mode->hdisplay * (bochs->bpp / 8);
+	bochs->yres_virtual = bochs->fb_size / bochs->stride;
+
+	DRM_DEBUG_DRIVER("%dx%d @ %d bpp, vy %d\n",
+			 bochs->xres, bochs->yres, bochs->bpp,
+			 bochs->yres_virtual);
+
+	bochs_vga_writeb(bochs, 0x3c0, 0x20); /* unblank */
+
+	bochs_dispi_write(bochs, VBE_DISPI_INDEX_BPP,         bochs->bpp);
+	bochs_dispi_write(bochs, VBE_DISPI_INDEX_XRES,        bochs->xres);
+	bochs_dispi_write(bochs, VBE_DISPI_INDEX_YRES,        bochs->yres);
+	bochs_dispi_write(bochs, VBE_DISPI_INDEX_BANK,        0);
+	bochs_dispi_write(bochs, VBE_DISPI_INDEX_VIRT_WIDTH,  bochs->xres);
+	bochs_dispi_write(bochs, VBE_DISPI_INDEX_VIRT_HEIGHT,
+			  bochs->yres_virtual);
+	bochs_dispi_write(bochs, VBE_DISPI_INDEX_X_OFFSET,    0);
+	bochs_dispi_write(bochs, VBE_DISPI_INDEX_Y_OFFSET,    0);
+
+	bochs_dispi_write(bochs, VBE_DISPI_INDEX_ENABLE,
+			  VBE_DISPI_ENABLED | VBE_DISPI_LFB_ENABLED);
+}
+
+void bochs_hw_setbase(struct bochs_device *bochs,
+		      int x, int y, u64 addr)
+{
+	unsigned long offset = (unsigned long)addr +
+		y * bochs->stride +
+		x * (bochs->bpp / 8);
+	int vy = offset / bochs->stride;
+	int vx = (offset % bochs->stride) * 8 / bochs->bpp;
+
+	DRM_DEBUG_DRIVER("x %d, y %d, addr %llx -> offset %lx, vx %d, vy %d\n",
+			 x, y, addr, offset, vx, vy);
+	bochs_dispi_write(bochs, VBE_DISPI_INDEX_X_OFFSET, vx);
+	bochs_dispi_write(bochs, VBE_DISPI_INDEX_Y_OFFSET, vy);
+}

drivers/gpu/drm/bochs/bochs_kms.c

+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include "bochs.h"
+
+static int defx = 1024;
+static int defy = 768;
+
+module_param(defx, int, 0444);
+module_param(defy, int, 0444);
+MODULE_PARM_DESC(defx, "default x resolution");
+MODULE_PARM_DESC(defy, "default y resolution");
+
+/* ---------------------------------------------------------------------- */
+
+static void bochs_crtc_load_lut(struct drm_crtc *crtc)
+{
+}
+
+static void bochs_crtc_dpms(struct drm_crtc *crtc, int mode)
+{
+	switch (mode) {
+	case DRM_MODE_DPMS_ON:
+	case DRM_MODE_DPMS_STANDBY:
+	case DRM_MODE_DPMS_SUSPEND:
+	case DRM_MODE_DPMS_OFF:
+	default:
+		return;
+	}
+}
+
+static bool bochs_crtc_mode_fixup(struct drm_crtc *crtc,
+				  const struct drm_display_mode *mode,
+				  struct drm_display_mode *adjusted_mode)
+{
+	return true;
+}
+
+static int bochs_crtc_mode_set_base(struct drm_crtc *crtc, int x, int y,
+				    struct drm_framebuffer *old_fb)
+{
+	struct bochs_device *bochs =
+		container_of(crtc, struct bochs_device, crtc);
+	struct bochs_framebuffer *bochs_fb;
+	struct bochs_bo *bo;
+	u64 gpu_addr = 0;
+	int ret;
+
+	if (old_fb) {
+		bochs_fb = to_bochs_framebuffer(old_fb);
+		bo = gem_to_bochs_bo(bochs_fb->obj);
+		ret = ttm_bo_reserve(&bo->bo, true, false, false, 0);
+		if (ret) {
+			DRM_ERROR("failed to reserve old_fb bo\n");
+		} else {
+			bochs_bo_unpin(bo);
+			ttm_bo_unreserve(&bo->bo);
+		}
+	}
+
+	if (WARN_ON(crtc->fb == NULL))
+		return -EINVAL;
+
+	bochs_fb = to_bochs_framebuffer(crtc->fb);
+	bo = gem_to_bochs_bo(bochs_fb->obj);
+	ret = ttm_bo_reserve(&bo->bo, true, false, false, 0);
+	if (ret)
+		return ret;
+
+	ret = bochs_bo_pin(bo, TTM_PL_FLAG_VRAM, &gpu_addr);
+	if (ret) {
+		ttm_bo_unreserve(&bo->bo);
+		return ret;
+	}
+
+	ttm_bo_unreserve(&bo->bo);
+	bochs_hw_setbase(bochs, x, y, gpu_addr);
+	return 0;
+}
+
+static int bochs_crtc_mode_set(struct drm_crtc *crtc,
+			       struct drm_display_mode *mode,
+			       struct drm_display_mode *adjusted_mode,
+			       int x, int y, struct drm_framebuffer *old_fb)
+{
+	struct bochs_device *bochs =
+		container_of(crtc, struct bochs_device, crtc);
+
+	bochs_hw_setmode(bochs, mode);
+	bochs_crtc_mode_set_base(crtc, x, y, old_fb);
+	return 0;
+}
+
+static void bochs_crtc_prepare(struct drm_crtc *crtc)
+{
+}
+
+static void bochs_crtc_commit(struct drm_crtc *crtc)
+{
+}
+
+static void bochs_crtc_gamma_set(struct drm_crtc *crtc, u16 *red, u16 *green,
+				 u16 *blue, uint32_t start, uint32_t size)
+{
+}
+
+/* These provide the minimum set of functions required to handle a CRTC */
+static const struct drm_crtc_funcs bochs_crtc_funcs = {
+	.gamma_set = bochs_crtc_gamma_set,
+	.set_config = drm_crtc_helper_set_config,
+	.destroy = drm_crtc_cleanup,
+};
+
+static const struct drm_crtc_helper_funcs bochs_helper_funcs = {
+	.dpms = bochs_crtc_dpms,
+	.mode_fixup = bochs_crtc_mode_fixup,
+	.mode_set = bochs_crtc_mode_set,
+	.mode_set_base = bochs_crtc_mode_set_base,
+	.prepare = bochs_crtc_prepare,
+	.commit = bochs_crtc_commit,
+	.load_lut = bochs_crtc_load_lut,
+};
+
+static void bochs_crtc_init(struct drm_device *dev)
+{
+	struct bochs_device *bochs = dev->dev_private;
+	struct drm_crtc *crtc = &bochs->crtc;
+
+	drm_crtc_init(dev, crtc, &bochs_crtc_funcs);
+	drm_mode_crtc_set_gamma_size(crtc, 256);
+	drm_crtc_helper_add(crtc, &bochs_helper_funcs);
+}
+
+static bool bochs_encoder_mode_fixup(struct drm_encoder *encoder,
+				     const struct drm_display_mode *mode,
+				     struct drm_display_mode *adjusted_mode)
+{
+	return true;
+}
+
+static void bochs_encoder_mode_set(struct drm_encoder *encoder,
+				   struct drm_display_mode *mode,
+				   struct drm_display_mode *adjusted_mode)
+{
+}
+
+static void bochs_encoder_dpms(struct drm_encoder *encoder, int state)
+{
+}
+
+static void bochs_encoder_prepare(struct drm_encoder *encoder)
+{
+}
+
+static void bochs_encoder_commit(struct drm_encoder *encoder)
+{
+}
+
+static const struct drm_encoder_helper_funcs bochs_encoder_helper_funcs = {
+	.dpms = bochs_encoder_dpms,
+	.mode_fixup = bochs_encoder_mode_fixup,
+	.mode_set = bochs_encoder_mode_set,
+	.prepare = bochs_encoder_prepare,
+	.commit = bochs_encoder_commit,
+};
+
+static const struct drm_encoder_funcs bochs_encoder_encoder_funcs = {
+	.destroy = drm_encoder_cleanup,
+};
+
+static void bochs_encoder_init(struct drm_device *dev)
+{
+	struct bochs_device *bochs = dev->dev_private;
+	struct drm_encoder *encoder = &bochs->encoder;
+
+	encoder->possible_crtcs = 0x1;
+	drm_encoder_init(dev, encoder, &bochs_encoder_encoder_funcs,
+			 DRM_MODE_ENCODER_DAC);
+	drm_encoder_helper_add(encoder, &bochs_encoder_helper_funcs);
+}
+
+
+int bochs_connector_get_modes(struct drm_connector *connector)
+{
+	int count;
+
+	count = drm_add_modes_noedid(connector, 8192, 8192);
+	drm_set_preferred_mode(connector, defx, defy);
+	return count;
+}
+
+static int bochs_connector_mode_valid(struct drm_connector *connector,
+				      struct drm_display_mode *mode)
+{
+	struct bochs_device *bochs =
+		container_of(connector, struct bochs_device, connector);
+	unsigned long size = mode->hdisplay * mode->vdisplay * 4;
+
+	/*
+	 * Make sure we can fit two framebuffers into video memory.
+	 * This allows up to 1600x1200 with 16 MB (default size).
+	 * If you want more try this:
+	 *     'qemu -vga std -global VGA.vgamem_mb=32 $otherargs'
+	 */
+	if (size * 2 > bochs->fb_size)
+		return MODE_BAD;
+
+	return MODE_OK;
+}
+
+static struct drm_encoder *
+bochs_connector_best_encoder(struct drm_connector *connector)
+{
+	int enc_id = connector->encoder_ids[0];
+	struct drm_mode_object *obj;
+	struct drm_encoder *encoder;
+
+	/* pick the encoder ids */
+	if (enc_id) {
+		obj = drm_mode_object_find(connector->dev, enc_id,
+					   DRM_MODE_OBJECT_ENCODER);
+		if (!obj)
+			return NULL;
+		encoder = obj_to_encoder(obj);
+		return encoder;
+	}
+	return NULL;
+}
+
+static enum drm_connector_status bochs_connector_detect(struct drm_connector
+							*connector, bool force)
+{
+	return connector_status_connected;
+}
+
+struct drm_connector_helper_funcs bochs_connector_connector_helper_funcs = {
+	.get_modes = bochs_connector_get_modes,
+	.mode_valid = bochs_connector_mode_valid,
+	.best_encoder = bochs_connector_best_encoder,
+};
+
+struct drm_connector_funcs bochs_connector_connector_funcs = {
+	.dpms = drm_helper_connector_dpms,
+	.detect = bochs_connector_detect,
+	.fill_modes = drm_helper_probe_single_connector_modes,
+	.destroy = drm_connector_cleanup,
+};
+
+static void bochs_connector_init(struct drm_device *dev)
+{
+	struct bochs_device *bochs = dev->dev_private;
+	struct drm_connector *connector = &bochs->connector;
+
+	drm_connector_init(dev, connector, &bochs_connector_connector_funcs,
+			   DRM_MODE_CONNECTOR_VIRTUAL);
+	drm_connector_helper_add(connector,
+				 &bochs_connector_connector_helper_funcs);
+}
+
+
+int bochs_kms_init(struct bochs_device *bochs)
+{
+	drm_mode_config_init(bochs->dev);
+	bochs->mode_config_initialized = true;
+
+	bochs->dev->mode_config.max_width = 8192;
+	bochs->dev->mode_config.max_height = 8192;
+
+	bochs->dev->mode_config.fb_base = bochs->fb_base;
+	bochs->dev->mode_config.preferred_depth = 24;
+	bochs->dev->mode_config.prefer_shadow = 0;
+
+	bochs->dev->mode_config.funcs = (void *)&bochs_mode_funcs;
+
+	bochs_crtc_init(bochs->dev);
+	bochs_encoder_init(bochs->dev);
+	bochs_connector_init(bochs->dev);
+	drm_mode_connector_attach_encoder(&bochs->connector,
+					  &bochs->encoder);
+
+	return 0;
+}
+
+void bochs_kms_fini(struct bochs_device *bochs)
+{
+	if (bochs->mode_config_initialized) {
+		drm_mode_config_cleanup(bochs->dev);
+		bochs->mode_config_initialized = false;
+	}
+}