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authorMichael Ellerman <michael@ellerman.id.au>2005-11-03 01:57:53 -0500
committerMichael Ellerman <michael@ellerman.id.au>2005-11-03 01:57:53 -0500
commitc87ef1171db207d9d19f87ad12db92974d95c466 (patch)
tree18f229ae7cd22fd7cb2c9ab54a6b5632a08d45c2 /include
parente19e4ab4154a831788365c07e7a10d9114bba46c (diff)
powerpc: Add helper functions for synthesising instructions at runtime
There's a few places already, and soon will be more, where we synthesise branch instructions at runtime. Rather than doing it by hand in each case, it would make sense to have one implementation. Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Diffstat (limited to 'include')
-rw-r--r--include/asm-powerpc/system.h48
1 files changed, 48 insertions, 0 deletions
diff --git a/include/asm-powerpc/system.h b/include/asm-powerpc/system.h
index 5b2ecbc47907..b5da0b851e02 100644
--- a/include/asm-powerpc/system.h
+++ b/include/asm-powerpc/system.h
@@ -359,5 +359,53 @@ extern void reloc_got2(unsigned long);
359 359
360#define PTRRELOC(x) ((typeof(x)) add_reloc_offset((unsigned long)(x))) 360#define PTRRELOC(x) ((typeof(x)) add_reloc_offset((unsigned long)(x)))
361 361
362static inline void create_instruction(unsigned long addr, unsigned int instr)
363{
364 unsigned int *p;
365 p = (unsigned int *)addr;
366 *p = instr;
367 asm ("dcbst 0, %0; sync; icbi 0,%0; sync; isync" : : "r" (p));
368}
369
370/* Flags for create_branch:
371 * "b" == create_branch(addr, target, 0);
372 * "ba" == create_branch(addr, target, BRANCH_ABSOLUTE);
373 * "bl" == create_branch(addr, target, BRANCH_SET_LINK);
374 * "bla" == create_branch(addr, target, BRANCH_ABSOLUTE | BRANCH_SET_LINK);
375 */
376#define BRANCH_SET_LINK 0x1
377#define BRANCH_ABSOLUTE 0x2
378
379static inline void create_branch(unsigned long addr,
380 unsigned long target, int flags)
381{
382 unsigned int instruction;
383
384 if (! (flags & BRANCH_ABSOLUTE))
385 target = target - addr;
386
387 /* Mask out the flags and target, so they don't step on each other. */
388 instruction = 0x48000000 | (flags & 0x3) | (target & 0x03FFFFFC);
389
390 create_instruction(addr, instruction);
391}
392
393static inline void create_function_call(unsigned long addr, void * func)
394{
395 unsigned long func_addr;
396
397#ifdef CONFIG_PPC64
398 /*
399 * On PPC64 the function pointer actually points to the function's
400 * descriptor. The first entry in the descriptor is the address
401 * of the function text.
402 */
403 func_addr = *(unsigned long *)func;
404#else
405 func_addr = (unsigned long)func;
406#endif
407 create_branch(addr, func_addr, BRANCH_SET_LINK);
408}
409
362#endif /* __KERNEL__ */ 410#endif /* __KERNEL__ */
363#endif /* _ASM_POWERPC_SYSTEM_H */ 411#endif /* _ASM_POWERPC_SYSTEM_H */