linux_dsm_epyc7002/arch/powerpc/kernel/trace/ftrace_32.S
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00

95 lines
1.8 KiB
ArmAsm

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* Split from entry_32.S
*/
#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 */