Revert "gpu/drm, x86, PAT: PAT support for io_mapping_*"

This reverts commit 17581ad812a9abb0182260374ef2e52d4a808a64.

Sitsofe Wheeler reported that /dev/dri/card0 is MIA on his EeePC 900
and bisected it to this commit.

Graphics card is an i915 in an EeePC 900:

 00:02.0 VGA compatible controller [0300]:
   Intel Corporation Mobile 915GM/GMS/910GML
     Express Graphics Controller [8086:2592] (rev 04)

( Most likely the ioremap() of the driver failed and hence the card
  did not initialize. )

Reported-by: Sitsofe Wheeler <sitsofe@yahoo.com>
Bisected-by: Sitsofe Wheeler <sitsofe@yahoo.com>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/arch/x86/include/asm/iomap.h b/arch/x86/include/asm/iomap.h
index bd46495..86af260 100644 (file)
--- a/arch/x86/include/asm/iomap.h
+++ b/arch/x86/include/asm/iomap.h
@@ -24,10 +24,7 @@
 #include <asm/tlbflush.h>
 
 int
-reserve_io_memtype_wc(u64 base, unsigned long size, pgprot_t *prot);
-
-void
-free_io_memtype(u64 base, unsigned long size);
+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 d5e2842..6c2b1af 100644 (file)
--- 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
-static int
+int
 is_io_mapping_possible(resource_size_t base, unsigned long size)
 {
        return 1;
 }
 #else
-static int
+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 */
@@ -38,46 +38,6 @@ 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;
-}
-EXPORT_SYMBOL_GPL(reserve_io_memtype_wc);
-
-void
-free_io_memtype(u64 base, unsigned long size)
-{
-       if (pat_enabled)
-               free_memtype(base, base + size);
-}
-EXPORT_SYMBOL_GPL(free_io_memtype);
-
 /* 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 f1ed66c..cbc2f0c 100644 (file)
--- a/include/linux/io-mapping.h
+++ b/include/linux/io-mapping.h
@@ -49,9 +49,8 @@ static inline struct io_mapping *
 io_mapping_create_wc(resource_size_t base, unsigned long size)
 {
        struct io_mapping *iomap;
-       pgprot_t prot;
 
-       if (!reserve_io_memtype_wc(base, size, &prot))
+       if (!is_io_mapping_possible(base, size))
                return NULL;
 
        iomap = kmalloc(sizeof(*iomap), GFP_KERNEL);
@@ -60,14 +59,13 @@ io_mapping_create_wc(resource_size_t base, unsigned long size)
 
        iomap->base = base;
        iomap->size = size;
-       iomap->prot = prot;
+       iomap->prot = pgprot_writecombine(__pgprot(__PAGE_KERNEL));
        return iomap;
 }
 
 static inline void
 io_mapping_free(struct io_mapping *mapping)
 {
-       free_io_memtype(mapping->base, mapping->size);
        kfree(mapping);
 }