[ARM] iop: iop3xx needs registers mapped uncached+unbuffered

Mikael Pettersson reported:

   The 2.6.28-rc kernels fail to detect PCI device 0000:00:01.0
   (the first ethernet port) on my Thecus n2100 XScale box.

   There is however still a strange "ghost" device that gets partially
   detected in 2.6.28-rc2 vanilla.

The IOP321 manual says:

  The user designates the memory region containing the OCCDR as
  non-cacheable and non-bufferable from the IntelR XScaleTM core.
  This guarantees that all load/stores to the OCCDR are only of
  DWORD quantities.

Ensure that the OCCDR is so mapped.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

3 files changed, 16 insertions, 8 deletions

diff --git a/arch/arm/include/asm/mach/map.h b/arch/arm/include/asm/mach/map.h
index cb1139ac1943..39d949b63e80 100644
--- a/arch/arm/include/asm/mach/map.h
+++ b/arch/arm/include/asm/mach/map.h
@@ -19,12 +19,13 @@ struct map_desc {
 };
 
 /* types 0-3 are defined in asm/io.h */
-#define MT_CACHECLEAN           4
-#define MT_MINICLEAN            5
-#define MT_LOW_VECTORS          6
-#define MT_HIGH_VECTORS         7
-#define MT_MEMORY               8
-#define MT_ROM                  9
+#define MT_UNCACHED             4
+#define MT_CACHECLEAN           5
+#define MT_MINICLEAN            6
+#define MT_LOW_VECTORS          7
+#define MT_HIGH_VECTORS         8
+#define MT_MEMORY               9
+#define MT_ROM                  10
 
 #ifdef CONFIG_MMU
 extern void iotable_init(struct map_desc *, int);
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index e63db11f16a8..7f36c825718d 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -208,6 +208,12 @@ static struct mem_type mem_types[] = {
                 .prot_sect      = PROT_SECT_DEVICE,
                 .domain         = DOMAIN_IO,
         },
+        [MT_UNCACHED] = {
+                .prot_pte       = PROT_PTE_DEVICE,
+                .prot_l1        = PMD_TYPE_TABLE,
+                .prot_sect      = PMD_TYPE_SECT | PMD_SECT_XN,
+                .domain         = DOMAIN_IO,
+        },
         [MT_CACHECLEAN] = {
                 .prot_sect = PMD_TYPE_SECT | PMD_SECT_XN,
                 .domain    = DOMAIN_KERNEL,
diff --git a/arch/arm/plat-iop/setup.c b/arch/arm/plat-iop/setup.c
index 4689db638e95..9e573e78176a 100644
--- a/arch/arm/plat-iop/setup.c
+++ b/arch/arm/plat-iop/setup.c
@@ -16,14 +16,15 @@
 #include <asm/hardware/iop3xx.h>
 
 /*
- * Standard IO mapping for all IOP3xx based systems
+ * Standard IO mapping for all IOP3xx based systems.  Note that
+ * the IOP3xx OCCDR must be mapped uncached and unbuffered.
  */
 static struct map_desc iop3xx_std_desc[] __initdata = {
          {      /* mem mapped registers */
                 .virtual        = IOP3XX_PERIPHERAL_VIRT_BASE,
                 .pfn            = __phys_to_pfn(IOP3XX_PERIPHERAL_PHYS_BASE),
                 .length         = IOP3XX_PERIPHERAL_SIZE,
-                .type           = MT_DEVICE,
+                .type           = MT_UNCACHED,
          }, {   /* PCI IO space */
                 .virtual        = IOP3XX_PCI_LOWER_IO_VA,
                 .pfn            = __phys_to_pfn(IOP3XX_PCI_LOWER_IO_PA),