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authorMichael Holzheu <holzheu@linux.vnet.ibm.com>2013-05-21 16:08:22 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2013-05-22 09:45:57 +0200
commit576ebd74928fd60ae112b33c42b89602015fadbd (patch)
tree724fb0a8f8e0d5f39bd9616a89c088046e7198ea
parentabd9a0c36028771a8f397f38bf79bfcf404f957f (diff)
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kernel: Fix s390 absolute memory access for /dev/mem
On s390 the prefix page and absolute zero pages are not correctly returned when reading /dev/mem. The reason is that the s390 asm/io.h file includes the asm-generic/io.h file which then defines xlate_dev_mem_ptr() and therefore overwrites the s390 specific version that does the correct swap operation for prefix and absolute zero pages. The problem is a regression that was introduced with git commit cd248341 (s390/pci: base support). To fix the problem add "#ifndef xlate_dev_mem_ptr" in asm-generic/io.h and "#define xlate_dev_mem_ptr" in asm/io.h. This ensures that the s390 version is used. For completeness also add the "#ifndef" construct for xlate_dev_kmem_ptr(). Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
-rw-r--r--arch/s390/include/asm/io.h1
-rw-r--r--include/asm-generic/io.h4
2 files changed, 5 insertions, 0 deletions
diff --git a/arch/s390/include/asm/io.h b/arch/s390/include/asm/io.h
index 379d96e2105..fd9be010f9b 100644
--- a/arch/s390/include/asm/io.h
+++ b/arch/s390/include/asm/io.h
@@ -36,6 +36,7 @@ static inline void * phys_to_virt(unsigned long address)
}
void *xlate_dev_mem_ptr(unsigned long phys);
+#define xlate_dev_mem_ptr xlate_dev_mem_ptr
void unxlate_dev_mem_ptr(unsigned long phys, void *addr);
/*
diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h
index ac9da00e9f2..d5afe96adba 100644
--- a/include/asm-generic/io.h
+++ b/include/asm-generic/io.h
@@ -343,8 +343,12 @@ extern void ioport_unmap(void __iomem *p);
#endif /* CONFIG_GENERIC_IOMAP */
#endif /* CONFIG_HAS_IOPORT */
+#ifndef xlate_dev_kmem_ptr
#define xlate_dev_kmem_ptr(p) p
+#endif
+#ifndef xlate_dev_mem_ptr
#define xlate_dev_mem_ptr(p) __va(p)
+#endif
#ifdef CONFIG_VIRT_TO_BUS
#ifndef virt_to_bus