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authorLen Brown <len.brown@intel.com>2010-08-15 01:06:31 -0400
committerLen Brown <len.brown@intel.com>2010-08-15 01:06:31 -0400
commit95ee46aa8698f2000647dfb362400fadbb5807cf (patch)
treee5a05c7297f997e191c73091934e42e3195c0e40 /arch/x86/include/asm/page.h
parentcfa806f059801dbe7e435745eb2e187c8bfe1e7f (diff)
parent92fa5bd9a946b6e7aab6764e7312e4e3d9bed295 (diff)
Merge branch 'linus' into release
Conflicts: drivers/acpi/debug.c Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'arch/x86/include/asm/page.h')
-rw-r--r--arch/x86/include/asm/page.h7
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/x86/include/asm/page.h b/arch/x86/include/asm/page.h
index 625c3f0e741..8ca82839288 100644
--- a/arch/x86/include/asm/page.h
+++ b/arch/x86/include/asm/page.h
@@ -37,6 +37,13 @@ static inline void copy_user_page(void *to, void *from, unsigned long vaddr,
#define __pa_nodebug(x) __phys_addr_nodebug((unsigned long)(x))
/* __pa_symbol should be used for C visible symbols.
This seems to be the official gcc blessed way to do such arithmetic. */
+/*
+ * We need __phys_reloc_hide() here because gcc may assume that there is no
+ * overflow during __pa() calculation and can optimize it unexpectedly.
+ * Newer versions of gcc provide -fno-strict-overflow switch to handle this
+ * case properly. Once all supported versions of gcc understand it, we can
+ * remove this Voodoo magic stuff. (i.e. once gcc3.x is deprecated)
+ */
#define __pa_symbol(x) __pa(__phys_reloc_hide((unsigned long)(x)))
#define __va(x) ((void *)((unsigned long)(x)+PAGE_OFFSET))