Subject: force proper address translation in Dell RBU

Replacing virt_to_phys() by virt_to_bus(), and adding code to ensure
contiguity as required by the firmware.

As usual, written and tested on 2.6.27.37 and made apply to the 2.6.18
tree without further testing.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxxxx>
Tested-by: Douglas Warzecha <Douglas_Warzecha@xxxxxxxx>

--- sle11-2009-10-16.orig/drivers/firmware/dell_rbu.c	2009-02-02 09:22:26.000000000 +0100
+++ sle11-2009-10-16/drivers/firmware/dell_rbu.c	2009-10-26 16:34:16.000000000 +0100
@@ -169,9 +169,28 @@ static int create_packet(void *data, siz
 			spin_lock(&rbu_data.lock);
 			goto out_alloc_packet_array;
 		}
+#ifdef CONFIG_XEN
+		if (ordernum && xen_create_contiguous_region(
+			(unsigned long)packet_data_temp_buf, ordernum, 0)) {
+			free_pages((unsigned long)packet_data_temp_buf,
+				   ordernum);
+			printk(KERN_WARNING
+				"dell_rbu:%s: failed to adjust new "
+				"packet\n", __func__);
+			retval = -ENOMEM;
+			spin_lock(&rbu_data.lock);
+			goto out_alloc_packet_array;
+		}
+#endif
 
-		if ((unsigned long)virt_to_phys(packet_data_temp_buf)
+		if ((unsigned long)virt_to_bus(packet_data_temp_buf)
 				< allocation_floor) {
+#ifdef CONFIG_XEN
+			if (ordernum)
+				xen_destroy_contiguous_region(
+					(unsigned long)packet_data_temp_buf,
+					ordernum);
+#endif
 			pr_debug("packet 0x%lx below floor at 0x%lx.\n",
 					(unsigned long)virt_to_phys(
 						packet_data_temp_buf),
@@ -185,7 +204,7 @@ static int create_packet(void *data, siz
 	newpacket->data = packet_data_temp_buf;
 
 	pr_debug("create_packet: newpacket at physical addr %lx\n",
-		(unsigned long)virt_to_phys(newpacket->data));
+		(unsigned long)virt_to_bus(newpacket->data));
 
 	/* packets may not have fixed size */
 	newpacket->length = length;
@@ -204,7 +223,7 @@ out_alloc_packet_array:
 	/* always free packet array */
 	for (;idx>0;idx--) {
 		pr_debug("freeing unused packet below floor 0x%lx.\n",
-			(unsigned long)virt_to_phys(
+			(unsigned long)virt_to_bus(
 				invalid_addr_packet_array[idx-1]));
 		free_pages((unsigned long)invalid_addr_packet_array[idx-1],
 			ordernum);
@@ -348,6 +367,13 @@ static void packet_empty_list(void)
 		 * to make sure there are no stale RBU packets left in memory
 		 */
 		memset(newpacket->data, 0, rbu_data.packetsize);
+#ifdef CONFIG_XEN
+		if (newpacket->ordernum)
+			xen_destroy_contiguous_region(
+				(unsigned long)newpacket->data,
+				newpacket->ordernum);
+#endif
+
 		free_pages((unsigned long) newpacket->data,
 			newpacket->ordernum);
 		kfree(newpacket);
@@ -402,7 +428,9 @@ static int img_update_realloc(unsigned l
 {
 	unsigned char *image_update_buffer = NULL;
 	unsigned long rc;
+#ifndef CONFIG_XEN
 	unsigned long img_buf_phys_addr;
+#endif
 	int ordernum;
 	int dma_alloc = 0;
 
@@ -433,15 +461,19 @@ static int img_update_realloc(unsigned l
 
 	spin_unlock(&rbu_data.lock);
 
+#ifndef CONFIG_XEN
 	ordernum = get_order(size);
 	image_update_buffer =
 		(unsigned char *) __get_free_pages(GFP_KERNEL, ordernum);
 
 	img_buf_phys_addr =
-		(unsigned long) virt_to_phys(image_update_buffer);
+		(unsigned long) virt_to_bus(image_update_buffer);
 
 	if (img_buf_phys_addr > BIOS_SCAN_LIMIT) {
 		free_pages((unsigned long) image_update_buffer, ordernum);
+#else
+	{
+#endif
 		ordernum = -1;
 		image_update_buffer = dma_alloc_coherent(NULL, size,
 			&dell_rbu_dmaaddr, GFP_KERNEL);
@@ -706,6 +738,12 @@ static struct bin_attribute rbu_packet_s
 static int __init dcdrbu_init(void)
 {
 	int rc = 0;
+
+#ifdef CONFIG_XEN
+	if (!is_initial_xendomain())
+		return -ENODEV;
+#endif
+
 	spin_lock_init(&rbu_data.lock);
 
 	init_packet_head();