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| author | Michael Holzheu <holzheu@linux.vnet.ibm.com> | 2013-05-21 16:08:22 +0200 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2013-05-22 09:45:57 +0200 |
| commit | 576ebd74928fd60ae112b33c42b89602015fadbd (patch) | |
| tree | 724fb0a8f8e0d5f39bd9616a89c088046e7198ea /include/asm-generic/io.h | |
| parent | abd9a0c36028771a8f397f38bf79bfcf404f957f (diff) | |
| download | lwn-576ebd74928fd60ae112b33c42b89602015fadbd.tar.gz lwn-576ebd74928fd60ae112b33c42b89602015fadbd.zip | |
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>
Diffstat (limited to 'include/asm-generic/io.h')
| -rw-r--r-- | include/asm-generic/io.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h index ac9da00e9f2c..d5afe96adba6 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 |