2
0
mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-21 03:33:59 +08:00
linux-next/arch/powerpc/include/asm/ftrace.h
Torsten Duwe 153086644f powerpc/ftrace: Add support for -mprofile-kernel ftrace ABI
The gcc switch -mprofile-kernel defines a new ABI for calling _mcount()
very early in the function with minimal overhead.

Although mprofile-kernel has been available since GCC 3.4, there were
bugs which were only fixed recently. Currently it is known to work in
GCC 4.9, 5 and 6.

Additionally there are two possible code sequences generated by the
flag, the first uses mflr/std/bl and the second is optimised to omit the
std. Currently only gcc 6 has the optimised sequence. This patch
supports both sequences.

Initial work started by Vojtech Pavlik, used with permission.

Key changes:
 - rework _mcount() to work for both the old and new ABIs.
 - implement new versions of ftrace_caller() and ftrace_graph_caller()
   which deal with the new ABI.
 - updates to __ftrace_make_nop() to recognise the new mcount calling
   sequence.
 - updates to __ftrace_make_call() to recognise the nop'ed sequence.
 - implement ftrace_modify_call().
 - updates to the module loader to surpress the toc save in the module
   stub when calling mcount with the new ABI.

Reviewed-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Torsten Duwe <duwe@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-03-07 14:53:55 +11:00

85 lines
2.1 KiB
C

#ifndef _ASM_POWERPC_FTRACE
#define _ASM_POWERPC_FTRACE
#ifdef CONFIG_FUNCTION_TRACER
#define MCOUNT_ADDR ((unsigned long)(_mcount))
#define MCOUNT_INSN_SIZE 4 /* sizeof mcount call */
#ifdef __ASSEMBLY__
/* Based off of objdump optput from glibc */
#define MCOUNT_SAVE_FRAME \
stwu r1,-48(r1); \
stw r3, 12(r1); \
stw r4, 16(r1); \
stw r5, 20(r1); \
stw r6, 24(r1); \
mflr r3; \
lwz r4, 52(r1); \
mfcr r5; \
stw r7, 28(r1); \
stw r8, 32(r1); \
stw r9, 36(r1); \
stw r10,40(r1); \
stw r3, 44(r1); \
stw r5, 8(r1)
#define MCOUNT_RESTORE_FRAME \
lwz r6, 8(r1); \
lwz r0, 44(r1); \
lwz r3, 12(r1); \
mtctr r0; \
lwz r4, 16(r1); \
mtcr r6; \
lwz r5, 20(r1); \
lwz r6, 24(r1); \
lwz r0, 52(r1); \
lwz r7, 28(r1); \
lwz r8, 32(r1); \
mtlr r0; \
lwz r9, 36(r1); \
lwz r10,40(r1); \
addi r1, r1, 48
#else /* !__ASSEMBLY__ */
extern void _mcount(void);
#ifdef CONFIG_DYNAMIC_FTRACE
# define FTRACE_ADDR ((unsigned long)ftrace_caller)
# define FTRACE_REGS_ADDR FTRACE_ADDR
static inline unsigned long ftrace_call_adjust(unsigned long addr)
{
/* reloction of mcount call site is the same as the address */
return addr;
}
struct dyn_arch_ftrace {
struct module *mod;
};
#endif /* CONFIG_DYNAMIC_FTRACE */
#endif /* __ASSEMBLY__ */
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
#define ARCH_SUPPORTS_FTRACE_OPS 1
#endif
#endif
#if defined(CONFIG_FTRACE_SYSCALLS) && defined(CONFIG_PPC64) && !defined(__ASSEMBLY__)
#if !defined(_CALL_ELF) || _CALL_ELF != 2
#define ARCH_HAS_SYSCALL_MATCH_SYM_NAME
static inline bool arch_syscall_match_sym_name(const char *sym, const char *name)
{
/*
* Compare the symbol name with the system call name. Skip the .sys or .SyS
* prefix from the symbol name and the sys prefix from the system call name and
* just match the rest. This is only needed on ppc64 since symbol names on
* 32bit do not start with a period so the generic function will work.
*/
return !strcmp(sym + 4, name + 3);
}
#endif
#endif /* CONFIG_FTRACE_SYSCALLS && CONFIG_PPC64 && !__ASSEMBLY__ */
#endif /* _ASM_POWERPC_FTRACE */