4 files changed, 78 insertions, 3 deletions

diff --git a/arch/sh/mm/Kconfig b/arch/sh/mm/Kconfig
index 555ec9714b9e..10c24356d2d5 100644
--- a/arch/sh/mm/Kconfig
+++ b/arch/sh/mm/Kconfig
@@ -57,7 +57,7 @@ config 32BIT
         bool
         default y if CPU_SH5
 
-config PMB
+config PMB_ENABLE
         bool "Support 32-bit physical addressing through PMB"
         depends on MMU && EXPERIMENTAL && (CPU_SUBTYPE_SH7780 || CPU_SUBTYPE_SH7785)
         select 32BIT
@@ -67,6 +67,33 @@ config PMB
           32-bits through the SH-4A PMB. If this is not set, legacy
           29-bit physical addressing will be used.
 
+choice
+        prompt "PMB handling type"
+        depends on PMB_ENABLE
+        default PMB_FIXED
+
+config PMB
+        bool "PMB"
+        depends on MMU && EXPERIMENTAL && (CPU_SUBTYPE_SH7780 || CPU_SUBTYPE_SH7785)
+        select 32BIT
+        help
+          If you say Y here, physical addressing will be extended to
+          32-bits through the SH-4A PMB. If this is not set, legacy
+          29-bit physical addressing will be used.
+
+config PMB_FIXED
+        bool "fixed PMB"
+        depends on MMU && EXPERIMENTAL && (CPU_SUBTYPE_SH7780 || \
+                                           CPU_SUBTYPE_SH7785)
+        select 32BIT
+        help
+          If this option is enabled, fixed PMB mappings are inherited
+          from the boot loader, and the kernel does not attempt dynamic
+          management. This is the closest to legacy 29-bit physical mode,
+          and allows systems to support up to 512MiB of system memory.
+
+endchoice
+
 config X2TLB
         bool "Enable extended TLB mode"
         depends on (CPU_SHX2 || CPU_SHX3) && MMU && EXPERIMENTAL
diff --git a/arch/sh/mm/Makefile_32 b/arch/sh/mm/Makefile_32
index cb2f3f299591..469ff1672451 100644
--- a/arch/sh/mm/Makefile_32
+++ b/arch/sh/mm/Makefile_32
@@ -35,6 +35,7 @@ endif
 
 obj-$(CONFIG_HUGETLB_PAGE)      += hugetlbpage.o
 obj-$(CONFIG_PMB)               += pmb.o
+obj-$(CONFIG_PMB_FIXED)         += pmb-fixed.o
 obj-$(CONFIG_NUMA)              += numa.o
 
 EXTRA_CFLAGS += -Werror
diff --git a/arch/sh/mm/ioremap_32.c b/arch/sh/mm/ioremap_32.c
index 8dc77026a0b5..60cc486d2c2c 100644
--- a/arch/sh/mm/ioremap_32.c
+++ b/arch/sh/mm/ioremap_32.c
@@ -59,11 +59,13 @@ void __iomem *__ioremap(unsigned long phys_addr, unsigned long size,
         if (is_pci_memaddr(phys_addr) && is_pci_memaddr(last_addr))
                 return (void __iomem *)phys_addr;
 
+#if !defined(CONFIG_PMB_FIXED)
         /*
          * Don't allow anybody to remap normal RAM that we're using..
          */
         if (phys_addr < virt_to_phys(high_memory))
                 return NULL;
+#endif
 
         /*
          * Mappings have to be page-aligned
@@ -81,7 +83,7 @@ void __iomem *__ioremap(unsigned long phys_addr, unsigned long size,
         area->phys_addr = phys_addr;
         orig_addr = addr = (unsigned long)area->addr;
 
-#ifdef CONFIG_32BIT
+#ifdef CONFIG_PMB
         /*
          * First try to remap through the PMB once a valid VMA has been
          * established. Smaller allocations (or the rest of the size
@@ -122,7 +124,7 @@ void __iounmap(void __iomem *addr)
         if (seg < P3SEG || vaddr >= P3_ADDR_MAX || is_pci_memaddr(vaddr))
                 return;
 
-#ifdef CONFIG_32BIT
+#ifdef CONFIG_PMB
         /*
          * Purge any PMB entries that may have been established for this
          * mapping, then proceed with conventional VMA teardown.
diff --git a/arch/sh/mm/pmb-fixed.c b/arch/sh/mm/pmb-fixed.c
new file mode 100644
index 000000000000..43c8eac4d8a1
--- /dev/null
+++ b/arch/sh/mm/pmb-fixed.c
@@ -0,0 +1,45 @@
+/*
+ * arch/sh/mm/fixed_pmb.c
+ *
+ * Copyright (C) 2009  Renesas Solutions Corp.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <linux/io.h>
+#include <asm/mmu.h>
+#include <asm/mmu_context.h>
+
+static int __uses_jump_to_uncached fixed_pmb_init(void)
+{
+        int i;
+        unsigned long addr, data;
+
+        jump_to_uncached();
+
+        for (i = 0; i < PMB_ENTRY_MAX; i++) {
+                addr = PMB_DATA + (i << PMB_E_SHIFT);
+                data = ctrl_inl(addr);
+                if (!(data & PMB_V))
+                        continue;
+
+                if (data & PMB_C) {
+#if defined(CONFIG_CACHE_WRITETHROUGH)
+                        data |= PMB_WT;
+#elif defined(CONFIG_CACHE_WRITEBACK)
+                        data &= ~PMB_WT;
+#else
+                        data &= ~(PMB_C | PMB_WT);
+#endif
+                }
+                ctrl_outl(data, addr);
+        }
+
+        back_to_cached();
+
+        return 0;
+}
+arch_initcall(fixed_pmb_init);