Commit c71b7eff authored by Anton Blanchard's avatar Anton Blanchard

powerpc: Add ABIv2 support to ppc_function_entry

Skip over the well known global entry point code for ABIv2.
Signed-off-by: default avatarAnton Blanchard <anton@samba.org>
parent 814e4cd9
...@@ -42,15 +42,47 @@ void __patch_exception(int exc, unsigned long addr); ...@@ -42,15 +42,47 @@ void __patch_exception(int exc, unsigned long addr);
} while (0) } while (0)
#endif #endif
#define OP_RT_RA_MASK 0xffff0000UL
#define LIS_R2 0x3c020000UL
#define ADDIS_R2_R12 0x3c4c0000UL
#define ADDI_R2_R2 0x38420000UL
static inline unsigned long ppc_function_entry(void *func) static inline unsigned long ppc_function_entry(void *func)
{ {
#ifdef CONFIG_PPC64 #if defined(CONFIG_PPC64)
#if defined(_CALL_ELF) && _CALL_ELF == 2
u32 *insn = func;
/*
* A PPC64 ABIv2 function may have a local and a global entry
* point. We need to use the local entry point when patching
* functions, so identify and step over the global entry point
* sequence.
*
* The global entry point sequence is always of the form:
*
* addis r2,r12,XXXX
* addi r2,r2,XXXX
*
* A linker optimisation may convert the addis to lis:
*
* lis r2,XXXX
* addi r2,r2,XXXX
*/
if ((((*insn & OP_RT_RA_MASK) == ADDIS_R2_R12) ||
((*insn & OP_RT_RA_MASK) == LIS_R2)) &&
((*(insn+1) & OP_RT_RA_MASK) == ADDI_R2_R2))
return (unsigned long)(insn + 2);
else
return (unsigned long)func;
#else
/* /*
* On PPC64 the function pointer actually points to the function's * On PPC64 ABIv1 the function pointer actually points to the
* descriptor. The first entry in the descriptor is the address * function's descriptor. The first entry in the descriptor is the
* of the function text. * address of the function text.
*/ */
return ((func_descr_t *)func)->entry; return ((func_descr_t *)func)->entry;
#endif
#else #else
return (unsigned long)func; return (unsigned long)func;
#endif #endif
......
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