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authorChen Gang <gang.chen.5i5j@gmail.com>2014-04-15 09:21:30 +0800
committerGuan Xuetao <gxt@mprc.pku.edu.cn>2014-06-20 08:22:40 +0800
commit8a016596a56282f1414cf90e575040cffdabe68e (patch)
tree7c64c581f6728435c5220bdc940ac3628f15715b
parentaaad61838242469b0f9724a6057ea74ab4e87369 (diff)
downloadlinux-stericsson-8a016596a56282f1414cf90e575040cffdabe68e.tar.gz
arch:unicore32:mm: add devmem_is_allowed() to support STRICT_DEVMEM
unicore32 supports STRICT_DEVMEM, so it needs devmem_is_allowed(), like some of other architectures have done (e.g. arm, powerpc, x86 ...). The related error with allmodconfig: CC drivers/char/mem.o drivers/char/mem.c: In function ‘range_is_allowed’: drivers/char/mem.c:69: error: implicit declaration of function ‘devmem_is_allowed’ make[2]: *** [drivers/char/mem.o] Error 1 make[1]: *** [drivers/char] Error 2 make: *** [drivers] Error 2 Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com> Acked-by: Xuetao Guan <gxt@mprc.pku.edu.cn> Signed-off-by: Xuetao Guan <gxt@mprc.pku.edu.cn>
-rw-r--r--arch/unicore32/include/asm/io.h23
1 files changed, 23 insertions, 0 deletions
diff --git a/arch/unicore32/include/asm/io.h b/arch/unicore32/include/asm/io.h
index d6920301465a..cb1d8fd2b16b 100644
--- a/arch/unicore32/include/asm/io.h
+++ b/arch/unicore32/include/asm/io.h
@@ -48,5 +48,28 @@ extern void __uc32_iounmap(volatile void __iomem *addr);
#define PIO_MASK (unsigned int)(IO_SPACE_LIMIT)
#define PIO_RESERVED (PIO_OFFSET + PIO_MASK + 1)
+#ifdef CONFIG_STRICT_DEVMEM
+
+#include <linux/ioport.h>
+#include <linux/mm.h>
+
+/*
+ * devmem_is_allowed() checks to see if /dev/mem access to a certain
+ * address is valid. The argument is a physical page number.
+ * We mimic x86 here by disallowing access to system RAM as well as
+ * device-exclusive MMIO regions. This effectively disable read()/write()
+ * on /dev/mem.
+ */
+static inline int devmem_is_allowed(unsigned long pfn)
+{
+ if (iomem_is_exclusive(pfn << PAGE_SHIFT))
+ return 0;
+ if (!page_is_ram(pfn))
+ return 1;
+ return 0;
+}
+
+#endif /* CONFIG_STRICT_DEVMEM */
+
#endif /* __KERNEL__ */
#endif /* __UNICORE_IO_H__ */