powerpc: Add ppc_function_entry() which gets the entry point for a function

Because function pointers point to different things on 32-bit vs 64-bit,
add a macro that deals with dereferencing the OPD on 64-bit.  The soon to
be merged ftrace wants this, as well as other code I am working on.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This commit is contained in:
Michael Ellerman 2008-06-24 11:32:28 +10:00 committed by Paul Mackerras
parent 053a858efa
commit 07630a37be

View file

@ -10,6 +10,8 @@
* 2 of the License, or (at your option) any later version.
*/
#include <asm/types.h>
/* Flags for create_branch:
* "b" == create_branch(addr, target, 0);
* "ba" == create_branch(addr, target, BRANCH_ABSOLUTE);
@ -24,4 +26,18 @@ unsigned int create_branch(const unsigned int *addr,
void patch_branch(unsigned int *addr, unsigned long target, int flags);
void patch_instruction(unsigned int *addr, unsigned int instr);
static inline unsigned long ppc_function_entry(void *func)
{
#ifdef CONFIG_PPC64
/*
* On PPC64 the function pointer actually points to the function's
* descriptor. The first entry in the descriptor is the address
* of the function text.
*/
return ((func_descr_t *)func)->entry;
#else
return (unsigned long)func;
#endif
}
#endif /* _ASM_POWERPC_CODE_PATCHING_H */