[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>

diff --git a/arch/arm/include/asm/mach/map.h b/arch/arm/include/asm/mach/map.h
index cb1139a..39d949b 100644 (file)
--- 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 e63db11..7f36c82 100644 (file)
--- 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 4689db6..9e573e7 100644 (file)
--- 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),