/* * 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/console.h> #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 */ int feature_resize; /* XENFB_TYPE_RESIZE ok */ struct xenfb_resize resize; /* protected by resize_lock */ int resize_dpy; /* ditto */ spinlock_t resize_lock; struct xenbus_device *xbdev; }; #define XENFB_DEFAULT_FB_LEN (XENFB_WIDTH * XENFB_HEIGHT * XENFB_DEPTH / 8) enum { KPARAM_MEM, KPARAM_WIDTH, KPARAM_HEIGHT, KPARAM_CNT }; static int video[KPARAM_CNT] = { 2, XENFB_WIDTH, XENFB_HEIGHT }; module_param_array(video, int, NULL, 0); MODULE_PARM_DESC(video, "Video memory size in MB, width, height in pixels (default 2,800,600)"); static void xenfb_make_preferred_console(void); static int xenfb_remove(struct xenbus_device *); static void xenfb_init_shared_page(struct xenfb_info *, struct fb_info *); static int xenfb_connect_backend(struct xenbus_device *, struct xenfb_info *); static void xenfb_disconnect_backend(struct xenfb_info *); static void xenfb_send_event(struct xenfb_info *info, union xenfb_out_event *event) { u32 prod; 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 void xenfb_do_update(struct xenfb_info *info, int x, int y, int w, int h) { union xenfb_out_event event; memset(&event, 0, sizeof(event)); event.type = XENFB_TYPE_UPDATE; event.update.x = x; event.update.y = y; event.update.width = w; event.update.height = h; /* caller ensures !xenfb_queue_full() */ xenfb_send_event(info, &event); } static void xenfb_do_resize(struct xenfb_info *info) { union xenfb_out_event event; memset(&event, 0, sizeof(event)); event.resize = info->resize; /* caller ensures !xenfb_queue_full() */ xenfb_send_event(info, &event); } 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_handle_resize_dpy(struct xenfb_info *info) { unsigned long flags; spin_lock_irqsave(&info->resize_lock, flags); if (info->resize_dpy) { if (!xenfb_queue_full(info)) { info->resize_dpy = 0; xenfb_do_resize(info); } } spin_unlock_irqrestore(&info->resize_lock, flags); } static void xenfb_refresh(struct xenfb_info *info, int x1, int y1, int w, int h) { unsigned long flags; int x2 = x1 + w - 1; int y2 = y1 + h - 1; xenfb_handle_resize_dpy(info); 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 int xenfb_check_var(struct fb_var_screeninfo *var, struct fb_info *info) { struct xenfb_info *xenfb_info; int required_mem_len; xenfb_info = info->par; if (!xenfb_info->feature_resize) { if (var->xres == video[KPARAM_WIDTH] && var->yres == video[KPARAM_HEIGHT] && var->bits_per_pixel == xenfb_info->page->depth) { return 0; } return -EINVAL; } /* Can't resize past initial width and height */ if (var->xres > video[KPARAM_WIDTH] || var->yres > video[KPARAM_HEIGHT]) return -EINVAL; required_mem_len = var->xres * var->yres * xenfb_info->page->depth / 8; if (var->bits_per_pixel == xenfb_info->page->depth && var->xres <= info->fix.line_length / (XENFB_DEPTH / 8) && required_mem_len <= info->fix.smem_len) { var->xres_virtual = var->xres; var->yres_virtual = var->yres; return 0; } return -EINVAL; } static int xenfb_set_par(struct fb_info *info) { struct xenfb_info *xenfb_info; unsigned long flags; xenfb_info = info->par; spin_lock_irqsave(&xenfb_info->resize_lock, flags); xenfb_info->resize.type = XENFB_TYPE_RESIZE; xenfb_info->resize.width = info->var.xres; xenfb_info->resize.height = info->var.yres; xenfb_info->resize.stride = info->fix.line_length; xenfb_info->resize.depth = info->var.bits_per_pixel; xenfb_info->resize.offset = 0; xenfb_info->resize_dpy = 1; spin_unlock_irqrestore(&xenfb_info->resize_lock, flags); return 0; } 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, .fb_check_var = xenfb_check_var, .fb_set_par = xenfb_set_par, }; 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 fb_size; int val; int ret; info = kzalloc(sizeof(*info), GFP_KERNEL); if (info == NULL) { xenbus_dev_fatal(dev, -ENOMEM, "allocating info structure"); return -ENOMEM; } /* Limit kernel param videoram amount to what is in xenstore */ if (xenbus_scanf(XBT_NIL, dev->otherend, "videoram", "%d", &val) == 1) { if (val < video[KPARAM_MEM]) video[KPARAM_MEM] = val; } /* If requested res does not fit in available memory, use default */ fb_size = video[KPARAM_MEM] * 1024 * 1024; if (video[KPARAM_WIDTH] * video[KPARAM_HEIGHT] * XENFB_DEPTH / 8 > fb_size) { video[KPARAM_WIDTH] = XENFB_WIDTH; video[KPARAM_HEIGHT] = XENFB_HEIGHT; fb_size = XENFB_DEFAULT_FB_LEN; } dev->dev.driver_data = info; info->xbdev = dev; info->irq = -1; info->x1 = info->y1 = INT_MAX; spin_lock_init(&info->dirty_lock); spin_lock_init(&info->resize_lock); info->fb = vmalloc(fb_size); if (info->fb == NULL) goto error_nomem; memset(info->fb, 0, fb_size); info->nr_pages = (fb_size + 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; /* 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 = video[KPARAM_WIDTH]; fb_info->var.yres_virtual = fb_info->var.yres = video[KPARAM_HEIGHT]; fb_info->var.bits_per_pixel = XENFB_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 = fb_info->var.xres * XENFB_DEPTH / 8; fb_info->fix.smem_start = 0; fb_info->fix.smem_len = fb_size; 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); xenfb_init_shared_page(info, 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; xenfb_make_preferred_console(); return 0; error_nomem: ret = -ENOMEM; xenbus_dev_fatal(dev, ret, "allocating device memory"); error: xenfb_remove(dev); return ret; } static __devinit void xenfb_make_preferred_console(void) { struct console *c; if (console_set_on_cmdline) return; acquire_console_sem(); for (c = console_drivers; c; c = c->next) { if (!strcmp(c->name, "tty") && c->index == 0) break; } release_console_sem(); if (c) { unregister_console(c); c->flags |= CON_CONSDEV; c->flags &= ~CON_PRINTBUFFER; /* don't print again */ register_console(c); } } 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, info->fb_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, struct fb_info *fb_info) { int i; int epd = PAGE_SIZE / sizeof(info->mfns[0]); for (i = 0; i < info->nr_pages; i++) info->mfns[i] = vmalloc_to_mfn(info->fb + i * PAGE_SIZE); for (i = 0; i * epd < info->nr_pages; i++) info->page->pd[i] = vmalloc_to_mfn(&info->mfns[i * epd]); info->page->width = fb_info->var.xres; info->page->height = fb_info->var.yres; info->page->depth = fb_info->var.bits_per_pixel; info->page->line_length = fb_info->fix.line_length; info->page->mem_length = fb_info->fix.smem_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; if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-resize", "%d", &val) < 0) val = 0; info->feature_resize = val; break; case XenbusStateClosing: xenbus_frontend_closed(dev); break; } } static struct xenbus_device_id xenfb_ids[] = { { "vfb" }, { "" } }; static struct xenbus_driver xenfb_driver = { .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 (!xen_domain()) return -ENODEV; /* Nothing to do if running in dom0. */ if (xen_initial_domain()) return -ENODEV; return xenbus_register_frontend(&xenfb_driver); } static void __exit xenfb_cleanup(void) { xenbus_unregister_driver(&xenfb_driver); } module_init(xenfb_init); module_exit(xenfb_cleanup); MODULE_DESCRIPTION("Xen virtual framebuffer device frontend"); MODULE_LICENSE("GPL"); MODULE_ALIAS("xen:vfb");