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Diffstat (limited to 'arch/powerpc/include/asm/code-patching.h')
| -rw-r--r-- | arch/powerpc/include/asm/code-patching.h | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/code-patching.h b/arch/powerpc/include/asm/code-patching.h new file mode 100644 index 000000000..840a5509b --- /dev/null +++ b/arch/powerpc/include/asm/code-patching.h @@ -0,0 +1,102 @@ +#ifndef _ASM_POWERPC_CODE_PATCHING_H +#define _ASM_POWERPC_CODE_PATCHING_H + +/* + * Copyright 2008, Michael Ellerman, IBM Corporation. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#include <asm/types.h> +#include <asm/ppc-opcode.h> + +/* Flags for create_branch: + * "b" == create_branch(addr, target, 0); + * "ba" == create_branch(addr, target, BRANCH_ABSOLUTE); + * "bl" == create_branch(addr, target, BRANCH_SET_LINK); + * "bla" == create_branch(addr, target, BRANCH_ABSOLUTE | BRANCH_SET_LINK); + */ +#define BRANCH_SET_LINK 0x1 +#define BRANCH_ABSOLUTE 0x2 + +unsigned int create_branch(const unsigned int *addr, + unsigned long target, int flags); +unsigned int create_cond_branch(const unsigned int *addr, + unsigned long target, int flags); +int patch_branch(unsigned int *addr, unsigned long target, int flags); +int patch_instruction(unsigned int *addr, unsigned int instr); + +int instr_is_relative_branch(unsigned int instr); +int instr_is_branch_to_addr(const unsigned int *instr, unsigned long addr); +unsigned long branch_target(const unsigned int *instr); +unsigned int translate_branch(const unsigned int *dest, + const unsigned int *src); +#ifdef CONFIG_PPC_BOOK3E_64 +void __patch_exception(int exc, unsigned long addr); +#define patch_exception(exc, name) do { \ + extern unsigned int name; \ + __patch_exception((exc), (unsigned long)&name); \ +} 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) +{ +#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 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 +} + +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 */ |