Re: [PATCH 1/2] PV framebuffer

[Markus Armbruster <armbru@redhat.com>]

Diffs since last iteration:

diff -rupN -x '*.orig' linux-2.6.16.29-xen-pvfb.old/drivers/xen/console/console.c linux-2.6.16.29-xen-pvfb/drivers/xen/console/console.c
--- linux-2.6.16.29-xen-pvfb.old/drivers/xen/console/console.c	2006-11-17 13:38:58.000000000 +0100
+++ linux-2.6.16.29-xen-pvfb/drivers/xen/console/console.c	2006-11-17 13:38:02.000000000 +0100
@@ -712,18 +712,13 @@ static int __init xencons_init(void)
 	printk("Xen virtual console successfully installed as %s%d\n",
 	       DRV(xencons_driver)->name, xc_num);
 
-        /* Don't need to check about graphical fb for domain 0 */
-        if (is_initial_xendomain())
-		return 0;
-
-	rc = 0;
-	if (xenbus_scanf(XBT_NIL, "console", "use_graphics", "%d", &rc) < 0)
-		printk(KERN_ERR "Unable to read console/use_graphics\n");
-	if (rc == 0) {
-               /* FIXME: this is ugly */
-	       unregister_console(&kcons_info);
-	       kcons_info.flags |= CON_CONSDEV;
-	       register_console(&kcons_info);
+        /* Check about framebuffer messing up the console */
+        if (!is_initial_xendomain() &&
+	    !xenbus_exists(XBT_NIL, "device", "vfb")) {
+		/* FIXME: this is ugly */
+		unregister_console(&kcons_info);
+		kcons_info.flags |= CON_CONSDEV;
+		register_console(&kcons_info);
 	}
 
 	return 0;
diff -rupN -x '*.orig' linux-2.6.16.29-xen-pvfb.old/drivers/xen/Kconfig linux-2.6.16.29-xen-pvfb/drivers/xen/Kconfig
--- linux-2.6.16.29-xen-pvfb.old/drivers/xen/Kconfig	2006-11-17 13:38:58.000000000 +0100
+++ linux-2.6.16.29-xen-pvfb/drivers/xen/Kconfig	2006-11-17 13:38:02.000000000 +0100
@@ -187,7 +187,7 @@ config XEN_FRAMEBUFFER
 
 config XEN_KEYBOARD
 	tristate "Keyboard-device frontend driver"
-	depends on XEN
+	depends on XEN && XEN_FRAMEBUFFER && INPUT
 	default y
 	help
 	  The keyboard-device frontend driver allows the kernel to create a
diff -rupN -x '*.orig' linux-2.6.16.29-xen-pvfb.old/drivers/xen/xenfb/xenfb.c linux-2.6.16.29-xen-pvfb/drivers/xen/xenfb/xenfb.c
--- linux-2.6.16.29-xen-pvfb.old/drivers/xen/xenfb/xenfb.c	2006-11-17 13:38:58.000000000 +0100
+++ linux-2.6.16.29-xen-pvfb/drivers/xen/xenfb/xenfb.c	2006-11-17 13:38:02.000000000 +0100
@@ -67,7 +67,7 @@ struct xenfb_info
 static int xenfb_fps = 20;
 static unsigned long xenfb_mem_len = XENFB_WIDTH * XENFB_HEIGHT * XENFB_DEPTH / 8;
 
-static int __devexit xenfb_remove(struct xenbus_device *);
+static int xenfb_remove(struct xenbus_device *);
 
 static void xenfb_do_update(struct xenfb_info *info,
 			    int x, int y, int w, int h)
@@ -482,7 +482,6 @@ static int __devinit xenfb_probe(struct 
 		goto error;
 	}
 
-	/* FIXME should this be delayed until backend XenbusStateConnected? */
 	ret = register_framebuffer(fb_info);
 	if (ret) {
 		fb_dealloc_cmap(&info->fb_info->cmap);
@@ -492,9 +491,11 @@ static int __devinit xenfb_probe(struct 
 	}
 	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;
 	}
@@ -553,10 +554,19 @@ static void xenfb_backend_changed(struct
 		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;
@@ -565,12 +575,13 @@ static void xenfb_backend_changed(struct
 		break;
 
 	case XenbusStateClosing:
+		// FIXME is this safe in any dev->state?
 		xenbus_frontend_closed(dev);
 		break;
 	}
 }
 
-static int __devexit xenfb_remove(struct xenbus_device *dev)
+static int xenfb_remove(struct xenbus_device *dev)
 {
 	struct xenfb_info *info = dev->dev.driver_data;
 
@@ -610,19 +621,12 @@ static struct xenbus_driver xenfb = {
 
 static int __init xenfb_init(void)
 {
-	int ret;
-
 	if (!is_running_on_xen())
 		return -ENODEV;
 
 	/* Nothing to do if running in dom0. */
 	if (is_initial_xendomain())
 		return -ENODEV;
-	/* if we're not set up to use graphics mode, then don't initialize */
-	if (xenbus_scanf(XBT_NIL, "console", "use_graphics", "%d", &ret) < 0)
-		return -ENODEV;
-	if (ret == 0)
-		return -ENODEV;
 
 	return xenbus_register_frontend(&xenfb);
 }
diff -rupN -x '*.orig' linux-2.6.16.29-xen-pvfb.old/drivers/xen/xenkbd/xenkbd.c linux-2.6.16.29-xen-pvfb/drivers/xen/xenkbd/xenkbd.c
--- linux-2.6.16.29-xen-pvfb.old/drivers/xen/xenkbd/xenkbd.c	2006-11-17 13:38:58.000000000 +0100
+++ linux-2.6.16.29-xen-pvfb/drivers/xen/xenkbd/xenkbd.c	2006-11-17 13:38:02.000000000 +0100
@@ -36,7 +36,7 @@ struct xenkbd_info
 	struct xenbus_device	*xbdev;
 };
 
-static int __devexit xenkbd_remove(struct xenbus_device *);
+static int xenkbd_remove(struct xenbus_device *);
 
 /*
  * Note: if you need to send out events, see xenfb_do_update() for how
@@ -108,7 +108,7 @@ int __devinit xenkbd_probe(struct xenbus
 	input_dev->evbit[0] = BIT(EV_KEY) | BIT(EV_REL) | BIT(EV_ABS);
 	input_dev->keybit[LONG(BTN_MOUSE)]
 		= BIT(BTN_LEFT) | BIT(BTN_MIDDLE) | BIT(BTN_RIGHT);
-	/* FIXME more buttons? */
+	/* TODO additional buttons */
 	input_dev->relbit[0] = BIT(REL_X) | BIT(REL_Y);
 
 	/* FIXME not sure this is quite right */
@@ -191,6 +191,7 @@ static void xenkbd_backend_changed(struc
 		break;
 
 	case XenbusStateInitWait:
+	InitWait:
 		ret = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
 				   "feature-abs-pointer", "%d", &val);
 		if (ret < 0)
@@ -205,6 +206,13 @@ static void xenkbd_backend_changed(struc
 		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 */
 		break;
 
 	case XenbusStateClosing:
@@ -213,7 +221,7 @@ static void xenkbd_backend_changed(struc
 	}
 }
 
-static int __devexit xenkbd_remove(struct xenbus_device *dev)
+static int xenkbd_remove(struct xenbus_device *dev)
 {
 	struct xenkbd_info *info = dev->dev.driver_data;
 
@@ -242,20 +250,12 @@ static struct xenbus_driver xenkbd = {
 
 static int __init xenkbd_init(void)
 {
-	int ret;
-
 	if (!is_running_on_xen())
 		return -ENODEV;
 
 	/* Nothing to do if running in dom0. */
 	if (is_initial_xendomain())
 		return -ENODEV;
-	/* if we're not set up to use graphics mode, then don't initialize */
-	if (xenbus_scanf(XBT_NIL, "console", "use_graphics", "%d", &ret) < 0)
-		return -ENODEV;
-	if (ret == 0)
-		return -ENODEV;
-
 
 	return xenbus_register_frontend(&xenkbd);
 }
diff -rupN -x '*.orig' linux-2.6.16.29-xen-pvfb.old/mm/memory.c linux-2.6.16.29-xen-pvfb/mm/memory.c
--- linux-2.6.16.29-xen-pvfb.old/mm/memory.c	2006-10-13 19:47:16.000000000 +0200
+++ linux-2.6.16.29-xen-pvfb/mm/memory.c	2006-11-17 13:38:02.000000000 +0100
@@ -882,6 +882,7 @@ unsigned long zap_page_range(struct vm_a
 		tlb_finish_mmu(tlb, address, end);
 	return end;
 }
+EXPORT_SYMBOL(zap_page_range);
 
 /*
  * Do a quick page-table lookup for a single page.