From 576ebd74928fd60ae112b33c42b89602015fadbd Mon Sep 17 00:00:00 2001 From: Michael Holzheu Date: Tue, 21 May 2013 16:08:22 +0200 Subject: [PATCH] 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 Signed-off-by: Martin Schwidefsky --- arch/s390/include/asm/io.h | 1 + include/asm-generic/io.h | 4 ++++ 2 files changed, 5 insertions(+) diff --git a/arch/s390/include/asm/io.h b/arch/s390/include/asm/io.h index 379d96e2105e..fd9be010f9b2 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 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 -- 2.39.2