sh: uncached mapping helpers.

This adds some helper routines for uncached mapping support. This
simplifies some of the cases where we need to check the uncached mapping
boundaries in addition to giving us a centralized location for building
more complex manipulation on top of.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

2 files changed, 20 insertions, 10 deletions

diff --git a/arch/sh/include/asm/page.h b/arch/sh/include/asm/page.h
index 3accdc5ab12..8237d9f53e5 100644
--- a/arch/sh/include/asm/page.h
+++ b/arch/sh/include/asm/page.h
@@ -50,13 +50,22 @@ extern unsigned long shm_align_mask;
 extern unsigned long max_low_pfn, min_low_pfn;
 extern unsigned long memory_start, memory_end;
 
+#ifdef CONFIG_UNCACHED_MAPPING
+extern unsigned long uncached_start, uncached_end;
+
+extern int virt_addr_uncached(unsigned long kaddr);
+extern void uncached_init(void);
+#else
+#define virt_addr_uncached(kaddr)       (0)
+#define uncached_init()                 do { } while (0)
+#endif
+
 static inline unsigned long
 pages_do_alias(unsigned long addr1, unsigned long addr2)
 {
         return (addr1 ^ addr2) & shm_align_mask;
 }
 
-
 #define clear_page(page)        memset((void *)(page), 0, PAGE_SIZE)
 extern void copy_page(void *to, void *from);
 
@@ -135,6 +144,14 @@ typedef struct page *pgtable_t;
 #define __va(x) ((void *)((unsigned long)(x)+PAGE_OFFSET))
 #endif
 
+#ifdef CONFIG_UNCACHED_MAPPING
+#define UNCAC_ADDR(addr)        ((addr) - PAGE_OFFSET + uncached_start)
+#define CAC_ADDR(addr)          ((addr) - uncached_start + PAGE_OFFSET)
+#else
+#define UNCAC_ADDR(addr)        ((addr))
+#define CAC_ADDR(addr)          ((addr))
+#endif
+
 #define pfn_to_kaddr(pfn)       __va((pfn) << PAGE_SHIFT)
 #define page_to_phys(page)      (page_to_pfn(page) << PAGE_SHIFT)
 
diff --git a/arch/sh/include/asm/ptrace.h b/arch/sh/include/asm/ptrace.h
index e879dffa324..e11b14ea2c4 100644
--- a/arch/sh/include/asm/ptrace.h
+++ b/arch/sh/include/asm/ptrace.h
@@ -139,15 +139,8 @@ static inline unsigned long profile_pc(struct pt_regs *regs)
 {
         unsigned long pc = instruction_pointer(regs);
 
-#ifdef CONFIG_UNCACHED_MAPPING
-        /*
-         * If PC points in to the uncached mapping, fix it up and hand
-         * back the cached equivalent.
-         */
-        if ((pc >= (memory_start + cached_to_uncached)) &&
-            (pc <  (memory_start + cached_to_uncached + uncached_size)))
-                pc -= cached_to_uncached;
-#endif
+        if (virt_addr_uncached(pc))
+                return CAC_ADDR(pc);
 
         return pc;
 }