diff options
Diffstat (limited to 'drivers/video/xen-fbfront.c')
| -rw-r--r-- | drivers/video/xen-fbfront.c | 550 |
1 files changed, 550 insertions, 0 deletions
diff --git a/drivers/video/xen-fbfront.c b/drivers/video/xen-fbfront.c new file mode 100644 index 00000000000..619a6f8d65a --- /dev/null +++ b/drivers/video/xen-fbfront.c @@ -0,0 +1,550 @@ +/* + * Xen para-virtual frame buffer device + * + * Copyright (C) 2005-2006 Anthony Liguori <aliguori@us.ibm.com> + * Copyright (C) 2006-2008 Red Hat, Inc., Markus Armbruster <armbru@redhat.com> + * + * Based on linux/drivers/video/q40fb.c + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file COPYING in the main directory of this archive for + * more details. + */ + +/* + * TODO: + * + * Switch to grant tables when they become capable of dealing with the + * frame buffer. + */ + +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/fb.h> +#include <linux/module.h> +#include <linux/vmalloc.h> +#include <linux/mm.h> +#include <asm/xen/hypervisor.h> +#include <xen/events.h> +#include <xen/page.h> +#include <xen/interface/io/fbif.h> +#include <xen/interface/io/protocols.h> +#include <xen/xenbus.h> + +struct xenfb_info { + unsigned char *fb; + struct fb_info *fb_info; + int x1, y1, x2, y2; /* dirty rectangle, + protected by dirty_lock */ + spinlock_t dirty_lock; + int nr_pages; + int irq; + struct xenfb_page *page; + unsigned long *mfns; + int update_wanted; /* XENFB_TYPE_UPDATE wanted */ + + struct xenbus_device *xbdev; +}; + +static u32 xenfb_mem_len = XENFB_WIDTH * XENFB_HEIGHT * XENFB_DEPTH / 8; + +static int xenfb_remove(struct xenbus_device *); +static void xenfb_init_shared_page(struct xenfb_info *); +static int xenfb_connect_backend(struct xenbus_device *, struct xenfb_info *); +static void xenfb_disconnect_backend(struct xenfb_info *); + +static void xenfb_do_update(struct xenfb_info *info, + int x, int y, int w, int h) +{ + union xenfb_out_event event; + u32 prod; + + event.type = XENFB_TYPE_UPDATE; + event.update.x = x; + event.update.y = y; + event.update.width = w; + event.update.height = h; + + prod = info->page->out_prod; + /* caller ensures !xenfb_queue_full() */ + mb(); /* ensure ring space available */ + XENFB_OUT_RING_REF(info->page, prod) = event; + wmb(); /* ensure ring contents visible */ + info->page->out_prod = prod + 1; + + notify_remote_via_irq(info->irq); +} + +static int xenfb_queue_full(struct xenfb_info *info) +{ + u32 cons, prod; + + prod = info->page->out_prod; + cons = info->page->out_cons; + return prod - cons == XENFB_OUT_RING_LEN; +} + +static void xenfb_refresh(struct xenfb_info *info, + int x1, int y1, int w, int h) +{ + unsigned long flags; + int y2 = y1 + h - 1; + int x2 = x1 + w - 1; + + if (!info->update_wanted) + return; + + spin_lock_irqsave(&info->dirty_lock, flags); + + /* Combine with dirty rectangle: */ + if (info->y1 < y1) + y1 = info->y1; + if (info->y2 > y2) + y2 = info->y2; + if (info->x1 < x1) + x1 = info->x1; + if (info->x2 > x2) + x2 = info->x2; + + if (xenfb_queue_full(info)) { + /* Can't send right now, stash it in the dirty rectangle */ + info->x1 = x1; + info->x2 = x2; + info->y1 = y1; + info->y2 = y2; + spin_unlock_irqrestore(&info->dirty_lock, flags); + return; + } + + /* Clear dirty rectangle: */ + info->x1 = info->y1 = INT_MAX; + info->x2 = info->y2 = 0; + + spin_unlock_irqrestore(&info->dirty_lock, flags); + + if (x1 <= x2 && y1 <= y2) + xenfb_do_update(info, x1, y1, x2 - x1 + 1, y2 - y1 + 1); +} + +static void xenfb_deferred_io(struct fb_info *fb_info, + struct list_head *pagelist) +{ + struct xenfb_info *info = fb_info->par; + struct page *page; + unsigned long beg, end; + int y1, y2, miny, maxy; + + miny = INT_MAX; + maxy = 0; + list_for_each_entry(page, pagelist, lru) { + beg = page->index << PAGE_SHIFT; + end = beg + PAGE_SIZE - 1; + y1 = beg / fb_info->fix.line_length; + y2 = end / fb_info->fix.line_length; + if (y2 >= fb_info->var.yres) + y2 = fb_info->var.yres - 1; + if (miny > y1) + miny = y1; + if (maxy < y2) + maxy = y2; + } + xenfb_refresh(info, 0, miny, fb_info->var.xres, maxy - miny + 1); +} + +static struct fb_deferred_io xenfb_defio = { + .delay = HZ / 20, + .deferred_io = xenfb_deferred_io, +}; + +static int xenfb_setcolreg(unsigned regno, unsigned red, unsigned green, + unsigned blue, unsigned transp, + struct fb_info *info) +{ + u32 v; + + if (regno > info->cmap.len) + return 1; + +#define CNVT_TOHW(val, width) ((((val)<<(width))+0x7FFF-(val))>>16) + red = CNVT_TOHW(red, info->var.red.length); + green = CNVT_TOHW(green, info->var.green.length); + blue = CNVT_TOHW(blue, info->var.blue.length); + transp = CNVT_TOHW(transp, info->var.transp.length); +#undef CNVT_TOHW + + v = (red << info->var.red.offset) | + (green << info->var.green.offset) | + (blue << info->var.blue.offset); + + switch (info->var.bits_per_pixel) { + case 16: + case 24: + case 32: + ((u32 *)info->pseudo_palette)[regno] = v; + break; + } + + return 0; +} + +static void xenfb_fillrect(struct fb_info *p, const struct fb_fillrect *rect) +{ + struct xenfb_info *info = p->par; + + sys_fillrect(p, rect); + xenfb_refresh(info, rect->dx, rect->dy, rect->width, rect->height); +} + +static void xenfb_imageblit(struct fb_info *p, const struct fb_image *image) +{ + struct xenfb_info *info = p->par; + + sys_imageblit(p, image); + xenfb_refresh(info, image->dx, image->dy, image->width, image->height); +} + +static void xenfb_copyarea(struct fb_info *p, const struct fb_copyarea *area) +{ + struct xenfb_info *info = p->par; + + sys_copyarea(p, area); + xenfb_refresh(info, area->dx, area->dy, area->width, area->height); +} + +static ssize_t xenfb_write(struct fb_info *p, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct xenfb_info *info = p->par; + ssize_t res; + + res = fb_sys_write(p, buf, count, ppos); + xenfb_refresh(info, 0, 0, info->page->width, info->page->height); + return res; +} + +static struct fb_ops xenfb_fb_ops = { + .owner = THIS_MODULE, + .fb_read = fb_sys_read, + .fb_write = xenfb_write, + .fb_setcolreg = xenfb_setcolreg, + .fb_fillrect = xenfb_fillrect, + .fb_copyarea = xenfb_copyarea, + .fb_imageblit = xenfb_imageblit, +}; + +static irqreturn_t xenfb_event_handler(int rq, void *dev_id) +{ + /* + * No in events recognized, simply ignore them all. + * If you need to recognize some, see xen-kbdfront's + * input_handler() for how to do that. + */ + struct xenfb_info *info = dev_id; + struct xenfb_page *page = info->page; + + if (page->in_cons != page->in_prod) { + info->page->in_cons = info->page->in_prod; + notify_remote_via_irq(info->irq); + } + + /* Flush dirty rectangle: */ + xenfb_refresh(info, INT_MAX, INT_MAX, -INT_MAX, -INT_MAX); + + return IRQ_HANDLED; +} + +static int __devinit xenfb_probe(struct xenbus_device *dev, + const struct xenbus_device_id *id) +{ + struct xenfb_info *info; + struct fb_info *fb_info; + int ret; + + info = kzalloc(sizeof(*info), GFP_KERNEL); + if (info == NULL) { + xenbus_dev_fatal(dev, -ENOMEM, "allocating info structure"); + return -ENOMEM; + } + dev->dev.driver_data = info; + info->xbdev = dev; + info->irq = -1; + info->x1 = info->y1 = INT_MAX; + spin_lock_init(&info->dirty_lock); + + info->fb = vmalloc(xenfb_mem_len); + if (info->fb == NULL) + goto error_nomem; + memset(info->fb, 0, xenfb_mem_len); + + info->nr_pages = (xenfb_mem_len + PAGE_SIZE - 1) >> PAGE_SHIFT; + + info->mfns = vmalloc(sizeof(unsigned long) * info->nr_pages); + if (!info->mfns) + goto error_nomem; + + /* set up shared page */ + info->page = (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO); + if (!info->page) + goto error_nomem; + + xenfb_init_shared_page(info); + + /* abusing framebuffer_alloc() to allocate pseudo_palette */ + fb_info = framebuffer_alloc(sizeof(u32) * 256, NULL); + if (fb_info == NULL) + goto error_nomem; + + /* complete the abuse: */ + fb_info->pseudo_palette = fb_info->par; + fb_info->par = info; + + fb_info->screen_base = info->fb; + + fb_info->fbops = &xenfb_fb_ops; + fb_info->var.xres_virtual = fb_info->var.xres = info->page->width; + fb_info->var.yres_virtual = fb_info->var.yres = info->page->height; + fb_info->var.bits_per_pixel = info->page->depth; + + fb_info->var.red = (struct fb_bitfield){16, 8, 0}; + fb_info->var.green = (struct fb_bitfield){8, 8, 0}; + fb_info->var.blue = (struct fb_bitfield){0, 8, 0}; + + fb_info->var.activate = FB_ACTIVATE_NOW; + fb_info->var.height = -1; + fb_info->var.width = -1; + fb_info->var.vmode = FB_VMODE_NONINTERLACED; + + fb_info->fix.visual = FB_VISUAL_TRUECOLOR; + fb_info->fix.line_length = info->page->line_length; + fb_info->fix.smem_start = 0; + fb_info->fix.smem_len = xenfb_mem_len; + strcpy(fb_info->fix.id, "xen"); + fb_info->fix.type = FB_TYPE_PACKED_PIXELS; + fb_info->fix.accel = FB_ACCEL_NONE; + + fb_info->flags = FBINFO_FLAG_DEFAULT; + + ret = fb_alloc_cmap(&fb_info->cmap, 256, 0); + if (ret < 0) { + framebuffer_release(fb_info); + xenbus_dev_fatal(dev, ret, "fb_alloc_cmap"); + goto error; + } + + fb_info->fbdefio = &xenfb_defio; + fb_deferred_io_init(fb_info); + + ret = register_framebuffer(fb_info); + if (ret) { + fb_deferred_io_cleanup(fb_info); + fb_dealloc_cmap(&fb_info->cmap); + framebuffer_release(fb_info); + xenbus_dev_fatal(dev, ret, "register_framebuffer"); + goto error; + } + info->fb_info = fb_info; + + ret = xenfb_connect_backend(dev, info); + if (ret < 0) + goto error; + + return 0; + + error_nomem: + ret = -ENOMEM; + xenbus_dev_fatal(dev, ret, "allocating device memory"); + error: + xenfb_remove(dev); + return ret; +} + +static int xenfb_resume(struct xenbus_device *dev) +{ + struct xenfb_info *info = dev->dev.driver_data; + + xenfb_disconnect_backend(info); + xenfb_init_shared_page(info); + return xenfb_connect_backend(dev, info); +} + +static int xenfb_remove(struct xenbus_device *dev) +{ + struct xenfb_info *info = dev->dev.driver_data; + + xenfb_disconnect_backend(info); + if (info->fb_info) { + fb_deferred_io_cleanup(info->fb_info); + unregister_framebuffer(info->fb_info); + fb_dealloc_cmap(&info->fb_info->cmap); + framebuffer_release(info->fb_info); + } + free_page((unsigned long)info->page); + vfree(info->mfns); + vfree(info->fb); + kfree(info); + + return 0; +} + +static unsigned long vmalloc_to_mfn(void *address) +{ + return pfn_to_mfn(vmalloc_to_pfn(address)); +} + +static void xenfb_init_shared_page(struct xenfb_info *info) +{ + int i; + + for (i = 0; i < info->nr_pages; i++) + info->mfns[i] = vmalloc_to_mfn(info->fb + i * PAGE_SIZE); + + info->page->pd[0] = vmalloc_to_mfn(info->mfns); + info->page->pd[1] = 0; + info->page->width = XENFB_WIDTH; + info->page->height = XENFB_HEIGHT; + info->page->depth = XENFB_DEPTH; + info->page->line_length = (info->page->depth / 8) * info->page->width; + info->page->mem_length = xenfb_mem_len; + info->page->in_cons = info->page->in_prod = 0; + info->page->out_cons = info->page->out_prod = 0; +} + +static int xenfb_connect_backend(struct xenbus_device *dev, + struct xenfb_info *info) +{ + int ret, evtchn; + struct xenbus_transaction xbt; + + ret = xenbus_alloc_evtchn(dev, &evtchn); + if (ret) + return ret; + ret = bind_evtchn_to_irqhandler(evtchn, xenfb_event_handler, + 0, dev->devicetype, info); + if (ret < 0) { + xenbus_free_evtchn(dev, evtchn); + xenbus_dev_fatal(dev, ret, "bind_evtchn_to_irqhandler"); + return ret; + } + info->irq = ret; + + again: + ret = xenbus_transaction_start(&xbt); + if (ret) { + xenbus_dev_fatal(dev, ret, "starting transaction"); + return ret; + } + ret = xenbus_printf(xbt, dev->nodename, "page-ref", "%lu", + virt_to_mfn(info->page)); + if (ret) + goto error_xenbus; + ret = xenbus_printf(xbt, dev->nodename, "event-channel", "%u", + evtchn); + if (ret) + goto error_xenbus; + ret = xenbus_printf(xbt, dev->nodename, "protocol", "%s", + XEN_IO_PROTO_ABI_NATIVE); + if (ret) + goto error_xenbus; + ret = xenbus_printf(xbt, dev->nodename, "feature-update", "1"); + if (ret) + goto error_xenbus; + ret = xenbus_transaction_end(xbt, 0); + if (ret) { + if (ret == -EAGAIN) + goto again; + xenbus_dev_fatal(dev, ret, "completing transaction"); + return ret; + } + + xenbus_switch_state(dev, XenbusStateInitialised); + return 0; + + error_xenbus: + xenbus_transaction_end(xbt, 1); + xenbus_dev_fatal(dev, ret, "writing xenstore"); + return ret; +} + +static void xenfb_disconnect_backend(struct xenfb_info *info) +{ + if (info->irq >= 0) + unbind_from_irqhandler(info->irq, info); + info->irq = -1; +} + +static void xenfb_backend_changed(struct xenbus_device *dev, + enum xenbus_state backend_state) +{ + struct xenfb_info *info = dev->dev.driver_data; + int val; + + switch (backend_state) { + case XenbusStateInitialising: + case XenbusStateInitialised: + case XenbusStateUnknown: + case XenbusStateClosed: + break; + + case XenbusStateInitWait: +InitWait: + xenbus_switch_state(dev, XenbusStateConnected); + break; + + case XenbusStateConnected: + /* + * Work around xenbus race condition: If backend goes + * through InitWait to Connected fast enough, we can + * get Connected twice here. + */ + if (dev->state != XenbusStateConnected) + goto InitWait; /* no InitWait seen yet, fudge it */ + + if (xenbus_scanf(XBT_NIL, info->xbdev->otherend, + "request-update", "%d", &val) < 0) + val = 0; + if (val) + info->update_wanted = 1; + break; + + case XenbusStateClosing: + xenbus_frontend_closed(dev); + break; + } +} + +static struct xenbus_device_id xenfb_ids[] = { + { "vfb" }, + { "" } +}; + +static struct xenbus_driver xenfb = { + .name = "vfb", + .owner = THIS_MODULE, + .ids = xenfb_ids, + .probe = xenfb_probe, + .remove = xenfb_remove, + .resume = xenfb_resume, + .otherend_changed = xenfb_backend_changed, +}; + +static int __init xenfb_init(void) +{ + if (!is_running_on_xen()) + return -ENODEV; + + /* Nothing to do if running in dom0. */ + if (is_initial_xendomain()) + return -ENODEV; + + return xenbus_register_frontend(&xenfb); +} + +static void __exit xenfb_cleanup(void) +{ + xenbus_unregister_driver(&xenfb); +} + +module_init(xenfb_init); +module_exit(xenfb_cleanup); + +MODULE_LICENSE("GPL"); |