Author: Venkatesh Pallipadi <venkatesh.pallipadi@xxxxxxxxx>
AuthorDate: Tue, 24 Feb 2009 17:35:14 -0800
Commit: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Wed, 25 Feb 2009 13:09:52 +0100
gpu/drm, x86, PAT: PAT support for io_mapping_*
Make io_mapping_create_wc and io_mapping_free go through PAT to make sure
that there are no memory type aliases.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@xxxxxxxxx>
Signed-off-by: Suresh Siddha <suresh.b.siddha@xxxxxxxxx>
Cc: Dave Airlie <airlied@xxxxxxxxxx>
Cc: Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx>
Cc: Eric Anholt <eric@xxxxxxxxxx>
Cc: Keith Packard <keithp@xxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
arch/x86/include/asm/iomap.h | 5 ++++-
arch/x86/mm/iomap_32.c | 42 ++++++++++++++++++++++++++++++++++++++++--
include/linux/io-mapping.h | 6 ++++--
3 files changed, 48 insertions(+), 5 deletions(-)
diff --git a/arch/x86/include/asm/iomap.h b/arch/x86/include/asm/iomap.h
index 86af260..bd46495 100644
--- a/arch/x86/include/asm/iomap.h
+++ b/arch/x86/include/asm/iomap.h
@@ -24,7 +24,10 @@
#include <asm/tlbflush.h>
int
-is_io_mapping_possible(resource_size_t base, unsigned long size);
+reserve_io_memtype_wc(u64 base, unsigned long size, pgprot_t *prot);
+
+void
+free_io_memtype(u64 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 6c2b1af..94596f7 100644
--- a/arch/x86/mm/iomap_32.c
+++ b/arch/x86/mm/iomap_32.c
@@ -21,13 +21,13 @@
#include <linux/module.h>
#ifdef CONFIG_X86_PAE
-int
+static int
is_io_mapping_possible(resource_size_t base, unsigned long size)
{
return 1;
}
#else
-int
+static 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 */
@@ -38,6 +38,44 @@ is_io_mapping_possible(resource_size_t base, unsigned long size)
}
#endif
+int
+reserve_io_memtype_wc(u64 base, unsigned long size, pgprot_t *prot)
+{
+ unsigned long ret_flag;
+
+ if (!is_io_mapping_possible(base, size))
+ goto out_err;
+
+ if (!pat_enabled) {
+ *prot = pgprot_noncached(PAGE_KERNEL);
+ return 0;
+ }
+
+ if (reserve_memtype(base, base + size, _PAGE_CACHE_WC, &ret_flag))
+ goto out_err;
+
+ if (ret_flag == _PAGE_CACHE_WB)
+ goto out_free;
+
+ if (kernel_map_sync_memtype(base, size, ret_flag))
+ goto out_free;
+
+ *prot = __pgprot(__PAGE_KERNEL | ret_flag);
+ return 0;
+
+out_free:
+ free_memtype(base, base + size);
+out_err:
+ return -EINVAL;
+}
+
+void
+free_io_memtype(u64 base, unsigned long size)
+{
+ if (pat_enabled)
+ free_memtype(base, base + size);
+}
+
/* 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 cbc2f0c..f1ed66c 100644
--- a/include/linux/io-mapping.h
+++ b/include/linux/io-mapping.h
@@ -49,8 +49,9 @@ static inline struct io_mapping *
io_mapping_create_wc(resource_size_t base, unsigned long size)
{
struct io_mapping *iomap;
+ pgprot_t prot;
- if (!is_io_mapping_possible(base, size))
+ if (!reserve_io_memtype_wc(base, size, &prot))
return NULL;
iomap = kmalloc(sizeof(*iomap), GFP_KERNEL);
@@ -59,13 +60,14 @@ io_mapping_create_wc(resource_size_t base, unsigned long size)
iomap->base = base;
iomap->size = size;
- iomap->prot = pgprot_writecombine(__pgprot(__PAGE_KERNEL));
+ iomap->prot = prot;
return iomap;
}
static inline void
io_mapping_free(struct io_mapping *mapping)
{
+ free_io_memtype(mapping->base, mapping->size);
kfree(mapping);
}
--
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