99 lines
2 KiB
ArmAsm
99 lines
2 KiB
ArmAsm
/*
|
|
* Split from entry_32.S
|
|
*
|
|
* 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 <linux/magic.h>
|
|
#include <asm/reg.h>
|
|
#include <asm/ppc_asm.h>
|
|
#include <asm/asm-offsets.h>
|
|
#include <asm/ftrace.h>
|
|
#include <asm/export.h>
|
|
|
|
_GLOBAL(mcount)
|
|
_GLOBAL(_mcount)
|
|
/*
|
|
* It is required that _mcount on PPC32 must preserve the
|
|
* link register. But we have r0 to play with. We use r0
|
|
* to push the return address back to the caller of mcount
|
|
* into the ctr register, restore the link register and
|
|
* then jump back using the ctr register.
|
|
*/
|
|
mflr r0
|
|
mtctr r0
|
|
lwz r0, 4(r1)
|
|
mtlr r0
|
|
bctr
|
|
|
|
_GLOBAL(ftrace_caller)
|
|
MCOUNT_SAVE_FRAME
|
|
/* r3 ends up with link register */
|
|
subi r3, r3, MCOUNT_INSN_SIZE
|
|
.globl ftrace_call
|
|
ftrace_call:
|
|
bl ftrace_stub
|
|
nop
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
.globl ftrace_graph_call
|
|
ftrace_graph_call:
|
|
b ftrace_graph_stub
|
|
_GLOBAL(ftrace_graph_stub)
|
|
#endif
|
|
MCOUNT_RESTORE_FRAME
|
|
/* old link register ends up in ctr reg */
|
|
bctr
|
|
|
|
EXPORT_SYMBOL(_mcount)
|
|
|
|
_GLOBAL(ftrace_stub)
|
|
blr
|
|
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
_GLOBAL(ftrace_graph_caller)
|
|
/* load r4 with local address */
|
|
lwz r4, 44(r1)
|
|
subi r4, r4, MCOUNT_INSN_SIZE
|
|
|
|
/* Grab the LR out of the caller stack frame */
|
|
lwz r3,52(r1)
|
|
|
|
bl prepare_ftrace_return
|
|
nop
|
|
|
|
/*
|
|
* prepare_ftrace_return gives us the address we divert to.
|
|
* Change the LR in the callers stack frame to this.
|
|
*/
|
|
stw r3,52(r1)
|
|
|
|
MCOUNT_RESTORE_FRAME
|
|
/* old link register ends up in ctr reg */
|
|
bctr
|
|
|
|
_GLOBAL(return_to_handler)
|
|
/* need to save return values */
|
|
stwu r1, -32(r1)
|
|
stw r3, 20(r1)
|
|
stw r4, 16(r1)
|
|
stw r31, 12(r1)
|
|
mr r31, r1
|
|
|
|
bl ftrace_return_to_handler
|
|
nop
|
|
|
|
/* return value has real return address */
|
|
mtlr r3
|
|
|
|
lwz r3, 20(r1)
|
|
lwz r4, 16(r1)
|
|
lwz r31,12(r1)
|
|
lwz r1, 0(r1)
|
|
|
|
/* Jump back to real return address */
|
|
blr
|
|
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
|