226 lines
5.5 KiB
ArmAsm
226 lines
5.5 KiB
ArmAsm
/*
|
|
* mcount and friends -- ftrace stuff
|
|
*
|
|
* Copyright (C) 2009-2010 Analog Devices Inc.
|
|
* Licensed under the GPL-2 or later.
|
|
*/
|
|
|
|
#include <linux/linkage.h>
|
|
#include <asm/ftrace.h>
|
|
|
|
.text
|
|
|
|
#ifdef CONFIG_DYNAMIC_FTRACE
|
|
|
|
/* Simple stub so we can boot the kernel until runtime patching has
|
|
* disabled all calls to this. Then it'll be unused.
|
|
*/
|
|
ENTRY(__mcount)
|
|
# if ANOMALY_05000371
|
|
nop; nop; nop; nop;
|
|
# endif
|
|
rts;
|
|
ENDPROC(__mcount)
|
|
|
|
/* GCC will have called us before setting up the function prologue, so we
|
|
* can clobber the normal scratch registers, but we need to make sure to
|
|
* save/restore the registers used for argument passing (R0-R2) in case
|
|
* the profiled function is using them. With data registers, R3 is the
|
|
* only one we can blow away. With pointer registers, we have P0-P2.
|
|
*
|
|
* Upon entry, the RETS will point to the top of the current profiled
|
|
* function. And since GCC pushed the previous RETS for us, the previous
|
|
* function will be waiting there. mmmm pie.
|
|
*/
|
|
ENTRY(_ftrace_caller)
|
|
# ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
|
|
/* optional micro optimization: return if stopped */
|
|
p1.l = _function_trace_stop;
|
|
p1.h = _function_trace_stop;
|
|
r3 = [p1];
|
|
cc = r3 == 0;
|
|
if ! cc jump _ftrace_stub (bp);
|
|
# endif
|
|
|
|
/* save first/second/third function arg and the return register */
|
|
[--sp] = r2;
|
|
[--sp] = r0;
|
|
[--sp] = r1;
|
|
[--sp] = rets;
|
|
|
|
/* function_trace_call(unsigned long ip, unsigned long parent_ip):
|
|
* ip: this point was called by ...
|
|
* parent_ip: ... this function
|
|
* the ip itself will need adjusting for the mcount call
|
|
*/
|
|
r0 = rets;
|
|
r1 = [sp + 16]; /* skip the 4 local regs on stack */
|
|
r0 += -MCOUNT_INSN_SIZE;
|
|
|
|
.globl _ftrace_call
|
|
_ftrace_call:
|
|
call _ftrace_stub
|
|
|
|
# ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
.globl _ftrace_graph_call
|
|
_ftrace_graph_call:
|
|
nop; /* jump _ftrace_graph_caller; */
|
|
# endif
|
|
|
|
/* restore state and get out of dodge */
|
|
.Lfinish_trace:
|
|
rets = [sp++];
|
|
r1 = [sp++];
|
|
r0 = [sp++];
|
|
r2 = [sp++];
|
|
|
|
.globl _ftrace_stub
|
|
_ftrace_stub:
|
|
rts;
|
|
ENDPROC(_ftrace_caller)
|
|
|
|
#else
|
|
|
|
/* See documentation for _ftrace_caller */
|
|
ENTRY(__mcount)
|
|
# ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
|
|
/* optional micro optimization: return if stopped */
|
|
p1.l = _function_trace_stop;
|
|
p1.h = _function_trace_stop;
|
|
r3 = [p1];
|
|
cc = r3 == 0;
|
|
if ! cc jump _ftrace_stub (bp);
|
|
# endif
|
|
|
|
/* save third function arg early so we can do testing below */
|
|
[--sp] = r2;
|
|
|
|
/* load the function pointer to the tracer */
|
|
p0.l = _ftrace_trace_function;
|
|
p0.h = _ftrace_trace_function;
|
|
r3 = [p0];
|
|
|
|
/* optional micro optimization: don't call the stub tracer */
|
|
r2.l = _ftrace_stub;
|
|
r2.h = _ftrace_stub;
|
|
cc = r2 == r3;
|
|
if ! cc jump .Ldo_trace;
|
|
|
|
# ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
/* if the ftrace_graph_return function pointer is not set to
|
|
* the ftrace_stub entry, call prepare_ftrace_return().
|
|
*/
|
|
p0.l = _ftrace_graph_return;
|
|
p0.h = _ftrace_graph_return;
|
|
r3 = [p0];
|
|
cc = r2 == r3;
|
|
if ! cc jump _ftrace_graph_caller;
|
|
|
|
/* similarly, if the ftrace_graph_entry function pointer is not
|
|
* set to the ftrace_graph_entry_stub entry, ...
|
|
*/
|
|
p0.l = _ftrace_graph_entry;
|
|
p0.h = _ftrace_graph_entry;
|
|
r2.l = _ftrace_graph_entry_stub;
|
|
r2.h = _ftrace_graph_entry_stub;
|
|
r3 = [p0];
|
|
cc = r2 == r3;
|
|
if ! cc jump _ftrace_graph_caller;
|
|
# endif
|
|
|
|
r2 = [sp++];
|
|
rts;
|
|
|
|
.Ldo_trace:
|
|
|
|
/* save first/second function arg and the return register */
|
|
[--sp] = r0;
|
|
[--sp] = r1;
|
|
[--sp] = rets;
|
|
|
|
/* setup the tracer function */
|
|
p0 = r3;
|
|
|
|
/* function_trace_call(unsigned long ip, unsigned long parent_ip):
|
|
* ip: this point was called by ...
|
|
* parent_ip: ... this function
|
|
* the ip itself will need adjusting for the mcount call
|
|
*/
|
|
r0 = rets;
|
|
r1 = [sp + 16]; /* skip the 4 local regs on stack */
|
|
r0 += -MCOUNT_INSN_SIZE;
|
|
|
|
/* call the tracer */
|
|
call (p0);
|
|
|
|
/* restore state and get out of dodge */
|
|
.Lfinish_trace:
|
|
rets = [sp++];
|
|
r1 = [sp++];
|
|
r0 = [sp++];
|
|
r2 = [sp++];
|
|
|
|
.globl _ftrace_stub
|
|
_ftrace_stub:
|
|
rts;
|
|
ENDPROC(__mcount)
|
|
|
|
#endif
|
|
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
/* The prepare_ftrace_return() function is similar to the trace function
|
|
* except it takes a pointer to the location of the frompc. This is so
|
|
* the prepare_ftrace_return() can hijack it temporarily for probing
|
|
* purposes.
|
|
*/
|
|
ENTRY(_ftrace_graph_caller)
|
|
# ifndef CONFIG_DYNAMIC_FTRACE
|
|
/* save first/second function arg and the return register */
|
|
[--sp] = r0;
|
|
[--sp] = r1;
|
|
[--sp] = rets;
|
|
|
|
/* prepare_ftrace_return(parent, self_addr, frame_pointer) */
|
|
r0 = sp; /* unsigned long *parent */
|
|
r1 = rets; /* unsigned long self_addr */
|
|
# else
|
|
r0 = sp; /* unsigned long *parent */
|
|
r1 = [sp]; /* unsigned long self_addr */
|
|
# endif
|
|
# ifdef CONFIG_HAVE_FUNCTION_GRAPH_FP_TEST
|
|
r2 = fp; /* unsigned long frame_pointer */
|
|
# endif
|
|
r0 += 16; /* skip the 4 local regs on stack */
|
|
r1 += -MCOUNT_INSN_SIZE;
|
|
call _prepare_ftrace_return;
|
|
|
|
jump .Lfinish_trace;
|
|
ENDPROC(_ftrace_graph_caller)
|
|
|
|
/* Undo the rewrite caused by ftrace_graph_caller(). The common function
|
|
* ftrace_return_to_handler() will return the original rets so we can
|
|
* restore it and be on our way.
|
|
*/
|
|
ENTRY(_return_to_handler)
|
|
/* make sure original return values are saved */
|
|
[--sp] = p0;
|
|
[--sp] = r0;
|
|
[--sp] = r1;
|
|
|
|
/* get original return address */
|
|
# ifdef CONFIG_HAVE_FUNCTION_GRAPH_FP_TEST
|
|
r0 = fp; /* Blackfin is sane, so omit this */
|
|
# endif
|
|
call _ftrace_return_to_handler;
|
|
rets = r0;
|
|
|
|
/* anomaly 05000371 - make sure we have at least three instructions
|
|
* between rets setting and the return
|
|
*/
|
|
r1 = [sp++];
|
|
r0 = [sp++];
|
|
p0 = [sp++];
|
|
rts;
|
|
ENDPROC(_return_to_handler)
|
|
#endif
|