# HG changeset patch
# User yamahata@xxxxxxxxxxxxx
# Date 1164001010 -32400
# Node ID 9a66bfb0e7a3a4d6294ff1ab7bdbc8ac9d353c36
# Parent  f0ba459065d32b61c9d04ccde5787e48e23be782
make xen /dev/mem aware of IA64 to use X.
The original /dev/mem (linux/drivers/char/mem.c) is aware of IA64 specific
issues. On the other hand paravirtualized /dev/mem
(linux-2.6-xen-sparse/drivers/xen/char/mem.c) is simplifed not to be aware
of IA64. This patch makes it IA64-aware to use X on domain0/IA64.
With this patch and ia64-specific patches, X server can boot on domain0/IA64.
PATCHNAME: xen_dev_mem_ia64

Signed-off-by: Isaku Yamahata <yamahata@xxxxxxxxxxxxx>

diff -r f0ba459065d3 -r 9a66bfb0e7a3 linux-2.6-xen-sparse/drivers/xen/char/mem.c
--- a/linux-2.6-xen-sparse/drivers/xen/char/mem.c	Thu Nov 16 18:47:28 2006 -0800
+++ b/linux-2.6-xen-sparse/drivers/xen/char/mem.c	Mon Nov 20 14:36:50 2006 +0900
@@ -28,13 +28,12 @@
 #include <asm/io.h>
 #include <asm/hypervisor.h>
 
-static inline int uncached_access(struct file *file)
-{
-	if (file->f_flags & O_SYNC)
-		return 1;
-	/* Xen sets correct MTRR type on non-RAM for us. */
-	return 0;
-}
+#ifndef ARCH_HAS_VALID_PHYS_ADDR_RANGE
+static inline int valid_phys_addr_range(unsigned long addr, size_t *count)
+{
+	return 1;
+}
+#endif
 
 /*
  * This funcion reads the *physical* memory. The f_pos points directly to the 
@@ -46,6 +45,9 @@ static ssize_t read_mem(struct file * fi
 	unsigned long p = *ppos, ignored;
 	ssize_t read = 0, sz;
 	void __iomem *v;
+
+	if (!valid_phys_addr_range(p, &count))
+		return -EFAULT;
 
 	while (count > 0) {
 		/*
@@ -58,7 +60,13 @@ static ssize_t read_mem(struct file * fi
 
 		sz = min_t(unsigned long, sz, count);
 
-		if ((v = ioremap(p, sz)) == NULL) {
+		/*
+		 * On ia64 if a page has been mapped somewhere as
+		 * uncached, then it must also be accessed uncached
+		 * by the kernel or data corruption may occur
+		 */
+		v = xlate_dev_mem_ptr(p, sz);
+		if (IS_ERR(v) || v == NULL) {
 			/*
 			 * Some programs (e.g., dmidecode) groove off into weird RAM
 			 * areas where no tables can possibly exist (because Xen will
@@ -68,12 +76,14 @@ static ssize_t read_mem(struct file * fi
 			 */
 			if (clear_user(buf, count))
 				return -EFAULT;
+			if (IS_ERR(v) && read == 0)
+				return PTR_ERR(v);
 			read += count;
 			break;
 		}
 
 		ignored = copy_to_user(buf, v, sz);
-		iounmap(v);
+		xlate_dev_mem_ptr_unmap(v);
 		if (ignored)
 			return -EFAULT;
 		buf += sz;
@@ -93,6 +103,9 @@ static ssize_t write_mem(struct file * f
 	ssize_t written = 0, sz;
 	void __iomem *v;
 
+	if (!valid_phys_addr_range(p, &count))
+		return -EFAULT;
+
 	while (count > 0) {
 		/*
 		 * Handle first page in case it's not aligned
@@ -104,11 +117,22 @@ static ssize_t write_mem(struct file * f
 
 		sz = min_t(unsigned long, sz, count);
 
-		if ((v = ioremap(p, sz)) == NULL)
-			break;
+		/*
+		 * On ia64 if a page has been mapped somewhere as
+		 * uncached, then it must also be accessed uncached
+		 * by the kernel or data corruption may occur
+		 */
+		v = xlate_dev_mem_ptr(p, sz);
+		if (v == NULL)
+			break;
+		if (IS_ERR(v)) {
+			if (written == 0)
+				return PTR_ERR(v);
+			break;
+		}
 
 		ignored = copy_from_user(v, buf, sz);
-		iounmap(v);
+		xlate_dev_mem_ptr_unmap(v);
 		if (ignored) {
 			written += sz - ignored;
 			if (written)
@@ -125,6 +149,15 @@ static ssize_t write_mem(struct file * f
 	return written;
 }
 
+#ifndef ARCH_HAS_DEV_MEM_MMAP_MEM
+static inline int uncached_access(struct file *file)
+{
+	if (file->f_flags & O_SYNC)
+		return 1;
+	/* Xen sets correct MTRR type on non-RAM for us. */
+	return 0;
+}
+
 static int mmap_mem(struct file * file, struct vm_area_struct * vma)
 {
 	size_t size = vma->vm_end - vma->vm_start;
@@ -136,6 +169,7 @@ static int mmap_mem(struct file * file, 
 	return direct_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
 				      size, vma->vm_page_prot, DOMID_IO);
 }
+#endif
 
 /*
  * The memory devices use the full 32/64 bits of the offset, and so we cannot
diff -r f0ba459065d3 -r 9a66bfb0e7a3 linux-2.6-xen-sparse/include/asm-i386/mach-xen/asm/io.h
--- a/linux-2.6-xen-sparse/include/asm-i386/mach-xen/asm/io.h	Thu Nov 16 18:47:28 2006 -0800
+++ b/linux-2.6-xen-sparse/include/asm-i386/mach-xen/asm/io.h	Mon Nov 20 14:36:50 2006 +0900
@@ -54,7 +54,8 @@
  * Convert a physical pointer to a virtual kernel pointer for /dev/mem
  * access
  */
-#define xlate_dev_mem_ptr(p)	__va(p)
+#define xlate_dev_mem_ptr(p, sz)	ioremap(p, sz)
+#define xlate_dev_mem_ptr_unmap(p)	iounmap(p)
 
 /*
  * Convert a virtual cached pointer to an uncached pointer
diff -r f0ba459065d3 -r 9a66bfb0e7a3 linux-2.6-xen-sparse/include/asm-x86_64/mach-xen/asm/io.h
--- a/linux-2.6-xen-sparse/include/asm-x86_64/mach-xen/asm/io.h	Thu Nov 16 18:47:28 2006 -0800
+++ b/linux-2.6-xen-sparse/include/asm-x86_64/mach-xen/asm/io.h	Mon Nov 20 14:36:50 2006 +0900
@@ -346,7 +346,8 @@ extern int iommu_bio_merge;
  * Convert a physical pointer to a virtual kernel pointer for /dev/mem
  * access
  */
-#define xlate_dev_mem_ptr(p)	__va(p)
+#define xlate_dev_mem_ptr(p, sz)	ioremap(p, sz)
+#define xlate_dev_mem_ptr_unmap(p)	iounmap(p)
 
 /*
  * Convert a virtual cached pointer to an uncached pointer