Fwd: [PATCH] c6x: asm: pgtable: Define dummy pgprot_writecombine for !MMU

Fwd: [PATCH] c6x: asm: pgtable: Define dummy pgprot_writecombine for !MMU

[Chen Gang S]

-------- Forwarded Message --------
Subject: [PATCH] c6x: asm: pgtable: Define dummy pgprot_writecombine for !MMU
Date: Tue, 03 Mar 2015 07:06:25 +0800
From: Chen Gang <762976180@qq.com>
To: msalter@redhat.com, a-jacquiot@ti.com
CC: kirill.shutemov@linux.intel.com, Andrew Morton <akpm@linux-foundation.org>, linux-c6x-dev@linux-c6x.org <linux-c6x-dev@linux-c6x.org>, linux-kernel@vger.kernel.org <linux-kernel@vger.kernel.org>

When !MMU, asm-generic will not define default pgprot_writecombine, so
c6x needs to define it by itself. The related error:

    CC [M]  fs/pstore/ram_core.o
  fs/pstore/ram_core.c: In function 'persistent_ram_vmap':
  fs/pstore/ram_core.c:399:10: error: implicit declaration of function 'pgprot_writecombine' [-Werror=implicit-function-declaration]
     prot = pgprot_writecombine(PAGE_KERNEL);
            ^
  fs/pstore/ram_core.c:399:8: error: incompatible types when assigning to type 'pgprot_t {aka struct <anonymous>}' from type 'int'
     prot = pgprot_writecombine(PAGE_KERNEL);
          ^

Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
---
 arch/c6x/include/asm/pgtable.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/c6x/include/asm/pgtable.h b/arch/c6x/include/asm/pgtable.h
index 78d4483..ec4db6d 100644
--- a/arch/c6x/include/asm/pgtable.h
+++ b/arch/c6x/include/asm/pgtable.h
@@ -67,6 +67,11 @@ extern unsigned long empty_zero_page;
  */
 #define pgtable_cache_init()   do { } while (0)
 
+/*
+ * c6x is !MMU, so define the simpliest implementation
+ */
+#define pgprot_writecombine pgprot_noncached
+
 #include <asm-generic/pgtable.h>
 
 #endif /* _ASM_C6X_PGTABLE_H */
-- 
1.9.3