# HG changeset patch
# User quintela@elfo.mitica
# Node ID b5b4c76164972243479a9cb2a428a93a5aef7263
# Parent  ad6b852bd54573cf46e8f34ffaeeae3877ec5603
devmem xen bits

diff -r ad6b852bd545 -r b5b4c7616497 arch/i386/mm/init-xen.c
--- a/arch/i386/mm/init-xen.c	Thu Jul 27 02:02:42 2006 +0200
+++ b/arch/i386/mm/init-xen.c	Thu Jul 27 02:21:44 2006 +0200
@@ -276,6 +276,25 @@ int page_is_ram(unsigned long pagenr)
 	return 0;
 }
 
+/*
+ * devmem_is_allowed() checks to see if /dev/mem access to a certain address is
+ * valid. The argument is a physical page number.
+ *
+ *
+ * On x86, access has to be given to the first megabyte of ram because that area
+ * contains bios code and data regions used by X and dosemu and similar apps.
+ * Access has to be given to non-kernel-ram areas as well, these contain the PCI
+ * mmio resources as well as potential bios/acpi data regions.
+ */
+int devmem_is_allowed(unsigned long pagenr)
+{
+   if (pagenr <= 256)
+       return 1;
+   if (!page_is_ram(pagenr))
+       return 1;
+   return 0;
+}
+
 #ifdef CONFIG_HIGHMEM
 pte_t *kmap_pte;
 pgprot_t kmap_prot;
diff -r ad6b852bd545 -r b5b4c7616497 arch/x86_64/mm/init-xen.c
--- a/arch/x86_64/mm/init-xen.c	Thu Jul 27 02:02:42 2006 +0200
+++ b/arch/x86_64/mm/init-xen.c	Thu Jul 27 02:21:44 2006 +0200
@@ -960,6 +960,31 @@ int __add_pages(struct zone *z, unsigned
 }
 #endif /* CONFIG_MEMORY_HOTPLUG */
 
+static inline int page_is_ram (unsigned long pagenr)
+{
+	return 1;
+}
+
+/*
+ * devmem_is_allowed() checks to see if /dev/mem access to a certain address is
+ * valid. The argument is a physical page number.
+ *
+ *
+ * On x86-64, access has to be given to the first megabyte of ram because that area
+ * contains bios code and data regions used by X and dosemu and similar apps.
+ * Access has to be given to non-kernel-ram areas as well, these contain the PCI
+ * mmio resources as well as potential bios/acpi data regions.
+ */
+int devmem_is_allowed(unsigned long pagenr)
+{
+	if (pagenr <= 256)
+		return 1;
+	if (!page_is_ram(pagenr))
+		return 1;
+	return 0;
+}
+
+
 static struct kcore_list kcore_mem, kcore_vmalloc, kcore_kernel, kcore_modules,
 			 kcore_vsyscall;
 
diff -r ad6b852bd545 -r b5b4c7616497 include/asm-i386/mach-xen/asm/page.h
--- a/include/asm-i386/mach-xen/asm/page.h	Thu Jul 27 02:02:42 2006 +0200
+++ b/include/asm-i386/mach-xen/asm/page.h	Thu Jul 27 02:21:44 2006 +0200
@@ -287,6 +287,8 @@ extern unsigned int __VMALLOC_RESERVE;
 
 extern int sysctl_legacy_va_layout;
 
+extern int devmem_is_allowed(unsigned long pagenr);
+
 extern int page_is_ram(unsigned long pagenr);
 
 #endif /* __ASSEMBLY__ */
diff -r ad6b852bd545 -r b5b4c7616497 include/asm-x86_64/mach-xen/asm/page.h
--- a/include/asm-x86_64/mach-xen/asm/page.h	Thu Jul 27 02:02:42 2006 +0200
+++ b/include/asm-x86_64/mach-xen/asm/page.h	Thu Jul 27 02:21:44 2006 +0200
@@ -322,6 +322,10 @@ static inline pgd_t __pgd(unsigned long 
 #include <asm-generic/memory_model.h>
 #include <asm-generic/page.h>
 
+#ifndef __ASSEMBLY__
+extern int devmem_is_allowed(unsigned long pagenr);
+#endif
+
 #endif /* __KERNEL__ */
 
 #endif /* _X86_64_PAGE_H */