[PATCH] cris: add pgprot_noncached

[Arnd Bergmann <arnd@arndb.de>]

On cris, the high address bit controls caching, which means that
we can add a pgprot_noncached() macro that sets this bit in the
address.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---

Jesper, does this patch make any sense to you? I could well
be misunderstanding how cris works.

 arch/cris/include/arch-v10/arch/mmu.h |    9 +++++----
 arch/cris/include/arch-v32/arch/mmu.h |   10 ++++++----
 arch/cris/include/asm/pgtable.h       |    2 ++
 3 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/arch/cris/include/arch-v10/arch/mmu.h b/arch/cris/include/arch-v10/arch/mmu.h
index df84f17..e829e5a 100644
--- a/arch/cris/include/arch-v10/arch/mmu.h
+++ b/arch/cris/include/arch-v10/arch/mmu.h
@@ -33,10 +33,10 @@ typedef struct
 
 /* CRIS PTE bits (see R_TLB_LO in the register description)
  *
- *   Bit:  31-13 12-------4    3        2       1       0  
- *         ________________________________________________
- *        | pfn | reserved | global | valid | kernel | we  |
- *        |_____|__________|________|_______|________|_____|
+ *   Bit:  31     30-13 12-------4    3        2       1       0
+ *         _______________________________________________________
+ *        | cache |pfn | reserved | global | valid | kernel | we  |
+ *        |_______|____|__________|________|_______|________|_____|
  *
  * (pfn = physical frame number)
  */
@@ -53,6 +53,7 @@ typedef struct
 #define _PAGE_VALID	   (1<<2) /* page is valid */
 #define _PAGE_SILENT_READ  (1<<2) /* synonym */
 #define _PAGE_GLOBAL       (1<<3) /* global page - context is ignored */
+#define _PAGE_NO_CACHE	   (1<<31) /* part of the uncached memory map */
 
 /* Bits the HW doesn't care about but the kernel uses them in SW */
 
diff --git a/arch/cris/include/arch-v32/arch/mmu.h b/arch/cris/include/arch-v32/arch/mmu.h
index 6bcdc3f..a05b033 100644
--- a/arch/cris/include/arch-v32/arch/mmu.h
+++ b/arch/cris/include/arch-v32/arch/mmu.h
@@ -28,10 +28,10 @@ typedef struct
 /*
  * CRISv32 PTE bits:
  *
- *  Bit:  31-13  12-5     4        3       2        1        0
- *       +-----+------+--------+-------+--------+-------+---------+
- *       | pfn | zero | global | valid | kernel | write | execute |
- *       +-----+------+--------+-------+--------+-------+---------+
+ *  Bit:   31     30-13  12-5     4        3       2        1        0
+ *       +-------+-----+------+--------+-------+--------+-------+---------+
+ *       | cache | pfn | zero | global | valid | kernel | write | execute |
+ *       +-------+-----+------+--------+-------+--------+-------+---------+
  */
 
 /*
@@ -45,6 +45,8 @@ typedef struct
 #define _PAGE_VALID         (1 << 3)	/* Page is valid. */
 #define _PAGE_SILENT_READ   (1 << 3)	/* Same as above. */
 #define _PAGE_GLOBAL        (1 << 4)	/* Global page. */
+#define _PAGE_NO_CACHE	    (1 <<31)	/* part of the uncached memory map */
+
 
 /*
  * The hardware doesn't care about these bits, but the kernel uses them in
diff --git a/arch/cris/include/asm/pgtable.h b/arch/cris/include/asm/pgtable.h
index 50aa974..1fcce00 100644
--- a/arch/cris/include/asm/pgtable.h
+++ b/arch/cris/include/asm/pgtable.h
@@ -197,6 +197,8 @@ static inline pte_t __mk_pte(void * page, pgprot_t pgprot)
 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 { pte_val(pte) = (pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot); return pte; }
 
+#define pgprot_noncached(prot) __pgprot((pgprot_val(prot) | _PAGE_NO_CACHE))
+
 
 /* pte_val refers to a page in the 0x4xxxxxxx physical DRAM interval
  * __pte_page(pte_val) refers to the "virtual" DRAM interval

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