From c71b7eff426fa7d8fd33e0964a7f79a3b41faff9 Mon Sep 17 00:00:00 2001 From: Anton Blanchard Date: Tue, 4 Feb 2014 16:09:15 +1100 Subject: powerpc: Add ABIv2 support to ppc_function_entry Skip over the well known global entry point code for ABIv2. Signed-off-by: Anton Blanchard --- arch/powerpc/include/asm/code-patching.h | 40 ++++++++++++++++++++++++++++---- 1 file changed, 36 insertions(+), 4 deletions(-) (limited to 'arch/powerpc/include/asm/code-patching.h') diff --git a/arch/powerpc/include/asm/code-patching.h b/arch/powerpc/include/asm/code-patching.h index 97e02f985df..37991e154ef 100644 --- a/arch/powerpc/include/asm/code-patching.h +++ b/arch/powerpc/include/asm/code-patching.h @@ -42,15 +42,47 @@ void __patch_exception(int exc, unsigned long addr); } while (0) #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) { -#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 - * descriptor. The first entry in the descriptor is the address - * of the function text. + * On PPC64 ABIv1 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; +#endif #else return (unsigned long)func; #endif -- cgit v1.2.3-70-g09d2 From d997c00c5a9b61474f7ff5f27ed64173bb007987 Mon Sep 17 00:00:00 2001 From: Michael Ellerman Date: Tue, 17 Jun 2014 16:15:32 +1000 Subject: powerpc: Add ppc_global_function_entry() ABIv2 has the concept of a global and local entry point to a function. In most cases we are interested in the local entry point, and so that is what ppc_function_entry() returns. However we have a case in the ftrace code where we want the global entry point, and there may be other places we need it too. Rather than special casing each, add an accessor. For ABIv1 and 32-bit there is only a single entry point, so we return that. That means it's safe for the caller to use this without also checking the ABI version. Signed-off-by: Michael Ellerman Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/include/asm/code-patching.h | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'arch/powerpc/include/asm/code-patching.h') diff --git a/arch/powerpc/include/asm/code-patching.h b/arch/powerpc/include/asm/code-patching.h index 37991e154ef..840a5509b3f 100644 --- a/arch/powerpc/include/asm/code-patching.h +++ b/arch/powerpc/include/asm/code-patching.h @@ -88,4 +88,15 @@ static inline unsigned long ppc_function_entry(void *func) #endif } +static inline unsigned long ppc_global_function_entry(void *func) +{ +#if defined(CONFIG_PPC64) && defined(_CALL_ELF) && _CALL_ELF == 2 + /* PPC64 ABIv2 the global entry point is at the address */ + return (unsigned long)func; +#else + /* All other cases there is no change vs ppc_function_entry() */ + return ppc_function_entry(func); +#endif +} + #endif /* _ASM_POWERPC_CODE_PATCHING_H */ -- cgit v1.2.3-70-g09d2