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authorVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>2009-02-25 04:35:12 +0300
committerIngo Molnar <mingo@elte.hu>2009-02-25 15:09:51 +0300
commit4ab0d47d0ab311eb181532c1ecb6d02905685071 (patch)
tree48b1a6cc01b65bab1442e05a971220366f998976
parent6644107d57a8fa82b47e4c55da4d9d91a612f29c (diff)
downloadlinux-4ab0d47d0ab311eb181532c1ecb6d02905685071.tar.xz
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>
-rw-r--r--arch/x86/include/asm/iomap.h3
-rw-r--r--arch/x86/mm/iomap_32.c18
-rw-r--r--include/linux/io-mapping.h46
3 files changed, 56 insertions, 11 deletions
diff --git a/arch/x86/include/asm/iomap.h b/arch/x86/include/asm/iomap.h
index c1f06289b14b..86af26091d6c 100644
--- a/arch/x86/include/asm/iomap.h
+++ b/arch/x86/include/asm/iomap.h
@@ -23,6 +23,9 @@
#include <asm/pgtable.h>
#include <asm/tlbflush.h>
+int
+is_io_mapping_possible(resource_size_t base, unsigned long size);
+
void *
iomap_atomic_prot_pfn(unsigned long pfn, enum km_type type, pgprot_t prot);
diff --git a/arch/x86/mm/iomap_32.c b/arch/x86/mm/iomap_32.c
index ca53224fc56c..6c2b1af16926 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 *
diff --git a/include/linux/io-mapping.h b/include/linux/io-mapping.h
index 82df31726a54..cbc2f0cd631b 100644
--- a/include/linux/io-mapping.h
+++ b/include/linux/io-mapping.h
@@ -30,11 +30,14 @@
* See Documentation/io_mapping.txt
*/
-/* this struct isn't actually defined anywhere */
-struct io_mapping;
-
#ifdef CONFIG_HAVE_ATOMIC_IOMAP
+struct io_mapping {
+ resource_size_t base;
+ unsigned long size;
+ pgprot_t prot;
+};
+
/*
* For small address space machines, mapping large objects
* into the kernel virtual space isn't practical. Where
@@ -43,23 +46,40 @@ struct io_mapping;
*/
static inline struct io_mapping *
-io_mapping_create_wc(unsigned long base, unsigned long size)
+io_mapping_create_wc(resource_size_t base, unsigned long size)
{
- return (struct io_mapping *) base;
+ struct io_mapping *iomap;
+
+ if (!is_io_mapping_possible(base, size))
+ return NULL;
+
+ iomap = kmalloc(sizeof(*iomap), GFP_KERNEL);
+ if (!iomap)
+ return NULL;
+
+ iomap->base = base;
+ iomap->size = size;
+ iomap->prot = pgprot_writecombine(__pgprot(__PAGE_KERNEL));
+ return iomap;
}
static inline void
io_mapping_free(struct io_mapping *mapping)
{
+ kfree(mapping);
}
/* Atomic map/unmap */
static inline void *
io_mapping_map_atomic_wc(struct io_mapping *mapping, unsigned long offset)
{
- offset += (unsigned long) mapping;
- return iomap_atomic_prot_pfn(offset >> PAGE_SHIFT, KM_USER0,
- __pgprot(__PAGE_KERNEL_WC));
+ resource_size_t phys_addr;
+ unsigned long pfn;
+
+ BUG_ON(offset >= mapping->size);
+ phys_addr = mapping->base + offset;
+ pfn = (unsigned long) (phys_addr >> PAGE_SHIFT);
+ return iomap_atomic_prot_pfn(pfn, KM_USER0, mapping->prot);
}
static inline void
@@ -71,8 +91,9 @@ io_mapping_unmap_atomic(void *vaddr)
static inline void *
io_mapping_map_wc(struct io_mapping *mapping, unsigned long offset)
{
- offset += (unsigned long) mapping;
- return ioremap_wc(offset, PAGE_SIZE);
+ BUG_ON(offset >= mapping->size);
+ resource_size_t phys_addr = mapping->base + offset;
+ return ioremap_wc(phys_addr, PAGE_SIZE);
}
static inline void
@@ -83,9 +104,12 @@ io_mapping_unmap(void *vaddr)
#else
+/* this struct isn't actually defined anywhere */
+struct io_mapping;
+
/* Create the io_mapping object*/
static inline struct io_mapping *
-io_mapping_create_wc(unsigned long base, unsigned long size)
+io_mapping_create_wc(resource_size_t base, unsigned long size)
{
return (struct io_mapping *) ioremap_wc(base, size);
}