--- /dev/null
+/*
+ * linux/drivers/video/xenfb.c -- Xen para-virtual frame buffer device
+ *
+ * Copyright (C) 2005-2006 Anthony Liguori <aliguori@us.ibm.com>
+ * Copyright (C) 2006 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 <linux/freezer.h>
+#include <asm/hypervisor.h>
+#include <xen/evtchn.h>
+#include <xen/interface/io/fbif.h>
+#include <xen/xenbus.h>
+#include <linux/kthread.h>
+
+struct xenfb_mapping
+{
+ struct list_head link;
+ struct vm_area_struct *vma;
+ atomic_t map_refs;
+ int faults;
+ struct xenfb_info *info;
+};
+
+struct xenfb_info
+{
+ struct task_struct *kthread;
+ wait_queue_head_t wq;
+
+ unsigned char *fb;
+ struct fb_info *fb_info;
+ struct timer_list refresh;
+ int dirty;
+ int x1, y1, x2, y2; /* dirty rectangle,
+ protected by dirty_lock */
+ spinlock_t dirty_lock;
+ struct mutex mm_lock;
+ int nr_pages;
+ struct page **pages;
+ struct list_head mappings; /* protected by mm_lock */
+
+ unsigned evtchn;
+ int irq;
+ struct xenfb_page *page;
+ unsigned long *mfns;
+ int update_wanted; /* XENFB_TYPE_UPDATE wanted */
+
+ struct xenbus_device *xbdev;
+};
+
+static int xenfb_fps = 20;
+static unsigned long 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_evtchn(info->evtchn);
+}
+
+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_update_screen(struct xenfb_info *info)
+{
+ unsigned long flags;
+ int y1, y2, x1, x2;
+ struct xenfb_mapping *map;
+
+ if (!info->update_wanted)
+ return;
+ if (xenfb_queue_full(info))
+ return;
+
+ mutex_lock(&info->mm_lock);
+
+ spin_lock_irqsave(&info->dirty_lock, flags);
+ y1 = info->y1;
+ y2 = info->y2;
+ x1 = info->x1;
+ x2 = info->x2;
+ info->x1 = info->y1 = INT_MAX;
+ info->x2 = info->y2 = 0;
+ spin_unlock_irqrestore(&info->dirty_lock, flags);
+
+ list_for_each_entry(map, &info->mappings, link) {
+ if (!map->faults)
+ continue;
+ zap_page_range(map->vma, map->vma->vm_start,
+ map->vma->vm_end - map->vma->vm_start, NULL);
+ map->faults = 0;
+ }
+
+ mutex_unlock(&info->mm_lock);
+
+ xenfb_do_update(info, x1, y1, x2 - x1, y2 - y1);
+}
+
+static int xenfb_thread(void *data)
+{
+ struct xenfb_info *info = data;
+
+ while (!kthread_should_stop()) {
+ if (info->dirty) {
+ info->dirty = 0;
+ xenfb_update_screen(info);
+ }
+ wait_event_interruptible(info->wq,
+ kthread_should_stop() || info->dirty);
+ try_to_freeze();
+ }
+ return 0;
+}
+
+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;
+
+ red >>= (16 - info->var.red.length);
+ green >>= (16 - info->var.green.length);
+ blue >>= (16 - info->var.blue.length);
+
+ v = (red << info->var.red.offset) |
+ (green << info->var.green.offset) |
+ (blue << info->var.blue.offset);
+
+ /* FIXME is this sane? check against xxxfb_setcolreg()! */
+ switch (info->var.bits_per_pixel) {
+ case 16:
+ case 24:
+ case 32:
+ ((u32 *)info->pseudo_palette)[regno] = v;
+ break;
+ }
+
+ return 0;
+}
+
+static void xenfb_timer(unsigned long data)
+{
+ struct xenfb_info *info = (struct xenfb_info *)data;
+ info->dirty = 1;
+ wake_up(&info->wq);
+}
+
+static void __xenfb_refresh(struct xenfb_info *info,
+ int x1, int y1, int w, int h)
+{
+ int y2, x2;
+
+ y2 = y1 + h;
+ x2 = x1 + w;
+
+ if (info->y1 > y1)
+ info->y1 = y1;
+ if (info->y2 < y2)
+ info->y2 = y2;
+ if (info->x1 > x1)
+ info->x1 = x1;
+ if (info->x2 < x2)
+ info->x2 = x2;
+
+ if (timer_pending(&info->refresh))
+ return;
+
+ mod_timer(&info->refresh, jiffies + HZ/xenfb_fps);
+}
+
+static void xenfb_refresh(struct xenfb_info *info,
+ int x1, int y1, int w, int h)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&info->dirty_lock, flags);
+ __xenfb_refresh(info, x1, y1, w, h);
+ spin_unlock_irqrestore(&info->dirty_lock, flags);
+}
+
+static void xenfb_fillrect(struct fb_info *p, const struct fb_fillrect *rect)
+{
+ struct xenfb_info *info = p->par;
+
+ cfb_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;
+
+ cfb_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;
+
+ cfb_copyarea(p, area);
+ xenfb_refresh(info, area->dx, area->dy, area->width, area->height);
+}
+
+static void xenfb_vm_open(struct vm_area_struct *vma)
+{
+ struct xenfb_mapping *map = vma->vm_private_data;
+ atomic_inc(&map->map_refs);
+}
+
+static void xenfb_vm_close(struct vm_area_struct *vma)
+{
+ struct xenfb_mapping *map = vma->vm_private_data;
+ struct xenfb_info *info = map->info;
+
+ mutex_lock(&info->mm_lock);
+ if (atomic_dec_and_test(&map->map_refs)) {
+ list_del(&map->link);
+ kfree(map);
+ }
+ mutex_unlock(&info->mm_lock);
+}
+
+static struct page *xenfb_vm_nopage(struct vm_area_struct *vma,
+ unsigned long vaddr, int *type)
+{
+ struct xenfb_mapping *map = vma->vm_private_data;
+ struct xenfb_info *info = map->info;
+ int pgnr = (vaddr - vma->vm_start) >> PAGE_SHIFT;
+ unsigned long flags;
+ struct page *page;
+ int y1, y2;
+
+ if (pgnr >= info->nr_pages)
+ return NOPAGE_SIGBUS;
+
+ mutex_lock(&info->mm_lock);
+ spin_lock_irqsave(&info->dirty_lock, flags);
+ page = info->pages[pgnr];
+ get_page(page);
+ map->faults++;
+
+ y1 = pgnr * PAGE_SIZE / info->fb_info->fix.line_length;
+ y2 = (pgnr * PAGE_SIZE + PAGE_SIZE - 1) / info->fb_info->fix.line_length;
+ if (y2 > info->fb_info->var.yres)
+ y2 = info->fb_info->var.yres;
+ __xenfb_refresh(info, 0, y1, info->fb_info->var.xres, y2 - y1);
+ spin_unlock_irqrestore(&info->dirty_lock, flags);
+ mutex_unlock(&info->mm_lock);
+
+ if (type)
+ *type = VM_FAULT_MINOR;
+
+ return page;
+}
+
+static struct vm_operations_struct xenfb_vm_ops = {
+ .open = xenfb_vm_open,
+ .close = xenfb_vm_close,
+ .nopage = xenfb_vm_nopage,
+};
+
+static int xenfb_mmap(struct fb_info *fb_info, struct vm_area_struct *vma)
+{
+ struct xenfb_info *info = fb_info->par;
+ struct xenfb_mapping *map;
+ int map_pages;
+
+ if (!(vma->vm_flags & VM_WRITE))
+ return -EINVAL;
+ if (!(vma->vm_flags & VM_SHARED))
+ return -EINVAL;
+ if (vma->vm_pgoff != 0)
+ return -EINVAL;
+
+ map_pages = (vma->vm_end - vma->vm_start + PAGE_SIZE-1) >> PAGE_SHIFT;
+ if (map_pages > info->nr_pages)
+ return -EINVAL;
+
+ map = kzalloc(sizeof(*map), GFP_KERNEL);
+ if (map == NULL)
+ return -ENOMEM;
+
+ map->vma = vma;
+ map->faults = 0;
+ map->info = info;
+ atomic_set(&map->map_refs, 1);
+
+ mutex_lock(&info->mm_lock);
+ list_add(&map->link, &info->mappings);
+ mutex_unlock(&info->mm_lock);
+
+ vma->vm_ops = &xenfb_vm_ops;
+ vma->vm_flags |= (VM_DONTEXPAND | VM_RESERVED);
+ vma->vm_private_data = map;
+
+ return 0;
+}
+
+static struct fb_ops xenfb_fb_ops = {
+ .owner = THIS_MODULE,
+ .fb_setcolreg = xenfb_setcolreg,
+ .fb_fillrect = xenfb_fillrect,
+ .fb_copyarea = xenfb_copyarea,
+ .fb_imageblit = xenfb_imageblit,
+ .fb_mmap = xenfb_mmap,
+};
+
+static irqreturn_t xenfb_event_handler(int rq, void *dev_id,
+ struct pt_regs *regs)
+{
+ /*
+ * No in events recognized, simply ignore them all.
+ * If you need to recognize some, see xenbkd'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_evtchn(info->evtchn);
+ }
+ return IRQ_HANDLED;
+}
+
+static unsigned long vmalloc_to_mfn(void *address)
+{
+ return pfn_to_mfn(vmalloc_to_pfn(address));
+}
+
+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);
+ mutex_init(&info->mm_lock);
+ init_waitqueue_head(&info->wq);
+ init_timer(&info->refresh);
+ info->refresh.function = xenfb_timer;
+ info->refresh.data = (unsigned long)info;
+ INIT_LIST_HEAD(&info->mappings);
+
+ 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->pages = kmalloc(sizeof(struct page *) * info->nr_pages,
+ GFP_KERNEL);
+ if (info->pages == NULL)
+ goto error_nomem;
+
+ 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);
+ if (!info->page)
+ goto error_nomem;
+
+ xenfb_init_shared_page(info);
+
+ fb_info = framebuffer_alloc(sizeof(u32) * 256, NULL);
+ /* see fishy hackery below */
+ if (fb_info == NULL)
+ goto error_nomem;
+
+ /* FIXME fishy hackery */
+ fb_info->pseudo_palette = fb_info->par;
+ fb_info->par = info;
+ /* /FIXME */
+ 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;
+ }
+
+ ret = register_framebuffer(fb_info);
+ if (ret) {
+ fb_dealloc_cmap(&info->fb_info->cmap);
+ framebuffer_release(fb_info);
+ xenbus_dev_fatal(dev, ret, "register_framebuffer");
+ goto error;
+ }
+ info->fb_info = fb_info;
+
+ /* FIXME should this be delayed until backend XenbusStateConnected? */
+ info->kthread = kthread_run(xenfb_thread, info, "xenfb thread");
+ if (IS_ERR(info->kthread)) {
+ ret = PTR_ERR(info->kthread);
+ info->kthread = NULL;
+ xenbus_dev_fatal(dev, ret, "register_framebuffer");
+ goto error;
+ }
+
+ 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;
+
+ del_timer(&info->refresh);
+ if (info->kthread)
+ kthread_stop(info->kthread);
+ xenfb_disconnect_backend(info);
+ if (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);
+ kfree(info->pages);
+ vfree(info->fb);
+ kfree(info);
+
+ return 0;
+}
+
+static void xenfb_init_shared_page(struct xenfb_info *info)
+{
+ int i;
+
+ for (i = 0; i < info->nr_pages; i++)
+ info->pages[i] = vmalloc_to_page(info->fb + i * PAGE_SIZE);
+
+ 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;
+ struct xenbus_transaction xbt;
+
+ ret = xenbus_alloc_evtchn(dev, &info->evtchn);
+ if (ret)
+ return ret;
+ ret = bind_evtchn_to_irqhandler(info->evtchn, xenfb_event_handler,
+ 0, "xenfb", info);
+ if (ret < 0) {
+ xenbus_free_evtchn(dev, info->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",
+ info->evtchn);
+ 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:
+ // FIXME is this safe in any dev->state?
+ 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)
+{
+ return xenbus_unregister_driver(&xenfb);
+}
+
+module_init(xenfb_init);
+module_exit(xenfb_cleanup);
+
+MODULE_LICENSE("GPL");
git://git.onelab.eu / linux-2.6.git / blobdiff