From 4ab0d47d0ab311eb181532c1ecb6d02905685071 Mon Sep 17 00:00:00 2001
From: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Date: Tue, 24 Feb 2009 17:35:12 -0800
Subject: gpu/drm, x86, PAT: io_mapping_create_wc and resource_size_t

io_mapping_create_wc should take a resource_size_t parameter in place of
unsigned long. With unsigned long, there will be no way to map greater than 4GB
address in i386/32 bit.

On x86, greater than 4GB addresses cannot be mapped on i386 without PAE. Return
error for such a case.

Patch also adds a structure for io_mapping, that saves the base, size and
type on HAVE_ATOMIC_IOMAP archs, that can be used to verify the offset on
io_mapping_map calls.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Eric Anholt <eric@anholt.net>
Cc: Keith Packard <keithp@keithp.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 arch/x86/mm/iomap_32.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

(limited to 'arch/x86/mm')

diff --git a/arch/x86/mm/iomap_32.c b/arch/x86/mm/iomap_32.c
index ca53224fc56..6c2b1af1692 100644
--- a/arch/x86/mm/iomap_32.c
+++ b/arch/x86/mm/iomap_32.c
@@ -20,6 +20,24 @@
 #include <asm/pat.h>
 #include <linux/module.h>
 
+#ifdef CONFIG_X86_PAE
+int
+is_io_mapping_possible(resource_size_t base, unsigned long size)
+{
+	return 1;
+}
+#else
+int
+is_io_mapping_possible(resource_size_t base, unsigned long size)
+{
+	/* There is no way to map greater than 1 << 32 address without PAE */
+	if (base + size > 0x100000000ULL)
+		return 0;
+
+	return 1;
+}
+#endif
+
 /* Map 'pfn' using fixed map 'type' and protections 'prot'
  */
 void *
-- 
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