Revert "[PATCH] x86: __pa and __pa_symbol address space separation"
This was broken. It adds complexity, for no good reason. Rather than
separate __pa() and __pa_symbol(), we should deprecate __pa_symbol(),
and preferably __pa() too - and just use "virt_to_phys()" instead, which
is more readable and has nicer semantics.
However, right now, just undo the separation, and make __pa_symbol() be
the exact same as __pa(). That fixes the bugs this patch introduced,
and we can do the fairly obvious cleanups later.
Do the new __phys_addr() function (which is now the actual workhorse for
the unified __pa()/__pa_symbol()) as a real external function, that way
all the potential issues with compile/link-time optimizations of
constant symbol addresses go away, and we can also, if we choose to, add
more sanity-checking of the argument.
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/asm-x86_64/page.h b/include/asm-x86_64/page.h
index b17fc16..4d04e24 100644
--- a/include/asm-x86_64/page.h
+++ b/include/asm-x86_64/page.h
@@ -94,26 +94,22 @@
#define KERNEL_TEXT_SIZE (40*1024*1024)
#define KERNEL_TEXT_START 0xffffffff80000000
+#define PAGE_OFFSET __PAGE_OFFSET
#ifndef __ASSEMBLY__
#include <asm/bug.h>
+extern unsigned long __phys_addr(unsigned long);
+
#endif /* __ASSEMBLY__ */
-#define PAGE_OFFSET __PAGE_OFFSET
-
-/* Note: __pa(&symbol_visible_to_c) should be always replaced with __pa_symbol.
- Otherwise you risk miscompilation. */
-#define __pa(x) ((unsigned long)(x) - PAGE_OFFSET)
-/* __pa_symbol should be used for C visible symbols.
- This seems to be the official gcc blessed way to do such arithmetic. */
-#define __pa_symbol(x) \
- ({unsigned long v; \
- asm("" : "=r" (v) : "0" (x)); \
- ((v - __START_KERNEL_map) + phys_base); })
+#define __pa(x) __phys_addr((unsigned long)(x))
+#define __pa_symbol(x) __phys_addr((unsigned long)(x))
#define __va(x) ((void *)((unsigned long)(x)+PAGE_OFFSET))
+#define __boot_va(x) __va(x)
+#define __boot_pa(x) __pa(x)
#ifdef CONFIG_FLATMEM
#define pfn_valid(pfn) ((pfn) < end_pfn)
#endif