From: Russell King <rmk@dyn-67.arm.linux.org.uk>
Date: Sun, 9 Nov 2008 11:18:36 +0000 (+0000)
Subject: [ARM] iop: iop3xx needs registers mapped uncached+unbuffered
X-Git-Tag: v3.12-rc1~17214^2~4
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=ebb4c65869db7213280ad9c510637683939b5ff8;p=kernel%2Fkernel-generic.git

[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
--- 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
--- 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
--- 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),