/*
* Low-level ftrace handling
*
* Copyright (C) 2009 Michal Simek <monstr@monstr.eu>
* Copyright (C) 2009 PetaLogix
*
* This file is subject to the terms and conditions of the GNU General
* Public License. See the file COPYING in the main directory of this
* archive for more details.
*/
#include <linux/linkage.h>
#define NOALIGN_ENTRY(name) .globl name; name:
/* FIXME MS: I think that I don't need to save all regs */
#define SAVE_REGS \
addik r1, r1, -120; \
swi r2, r1, 4; \
swi r3, r1, 8; \
swi r4, r1, 12; \
swi r5, r1, 116; \
swi r6, r1, 16; \
swi r7, r1, 20; \
swi r8, r1, 24; \
swi r9, r1, 28; \
swi r10, r1, 32; \
swi r11, r1, 36; \
swi r12, r1, 40; \
swi r13, r1, 44; \
swi r14, r1, 48; \
swi r16, r1, 52; \
swi r17, r1, 56; \
swi r18, r1, 60; \
swi r19, r1, 64; \
swi r20, r1, 68; \
swi r21, r1, 72; \
swi r22, r1, 76; \
swi r23, r1, 80; \
swi r24, r1, 84; \
swi r25, r1, 88; \
swi r26, r1, 92; \
swi r27, r1, 96; \
swi r28, r1, 100; \
swi r29, r1, 104; \
swi r30, r1, 108; \
swi r31, r1, 112;
#define RESTORE_REGS \
lwi r2, r1, 4; \
lwi r3, r1, 8; \
lwi r4, r1, 12; \
lwi r5, r1, 116; \
lwi r6, r1, 16; \
lwi r7, r1, 20; \
lwi r8, r1, 24; \
lwi r9, r1, 28; \
lwi r10, r1, 32; \
lwi r11, r1, 36; \
lwi r12, r1, 40; \
lwi r13, r1, 44; \
lwi r14, r1, 48; \
lwi r16, r1, 52; \
lwi r17, r1, 56; \
lwi r18, r1, 60; \
lwi r19, r1, 64; \
lwi r20, r1, 68; \
lwi r21, r1, 72; \
lwi r22, r1, 76; \
lwi r23, r1, 80; \
lwi r24, r1, 84; \
lwi r25, r1, 88; \
lwi r26, r1, 92; \
lwi r27, r1, 96; \
lwi r28, r1, 100; \
lwi r29, r1, 104; \
lwi r30, r1, 108; \
lwi r31, r1, 112; \
addik r1, r1, 120;
ENTRY(ftrace_stub)
rtsd r15, 8;
nop;
ENTRY(_mcount)
#ifdef CONFIG_DYNAMIC_FTRACE
ENTRY(ftrace_caller)
/* MS: It is just barrier which is removed from C code */
rtsd r15, 8
nop
#endif /* CONFIG_DYNAMIC_FTRACE */
SAVE_REGS
swi r15, r1, 0;
/* MS: HAVE_FUNCTION_TRACE_MCOUNT_TEST begin of checking */
lwi r5, r0, function_trace_stop;
bneid r5, end;
nop;
/* MS: HAVE_FUNCTION_TRACE_MCOUNT_TEST end of checking */
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
#ifndef CONFIG_DYNAMIC_FTRACE
lwi r5, r0, ftrace_graph_return;
addik r6, r0, ftrace_stub; /* asm implementation */
cmpu r5, r5, r6; /* ftrace_graph_return != ftrace_stub */
beqid r5, end_graph_tracer;
nop;
lwi r6, r0, ftrace_graph_entry;
addik r5, r0, ftrace_graph_entry_stub; /* implemented in C */
cmpu r5, r5, r6; /* ftrace_graph_entry != ftrace_graph_entry_stub */
beqid r5, end_graph_tracer;
nop;
#else /* CONFIG_DYNAMIC_FTRACE */
NOALIGN_ENTRY(ftrace_call_graph)
/* MS: jump over graph function - replaced from C code */
bri end_graph_tracer
#endif /* CONFIG_DYNAMIC_FTRACE */
addik r5, r1, 120; /* MS: load parent addr */
addik r6, r15, 0; /* MS: load current function addr */
bralid r15, prepare_ftrace_return;
nop;
/* MS: graph was taken that's why - can jump over function trace */
brid end;
nop;
end_graph_tracer:
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
#ifndef CONFIG_DYNAMIC_FTRACE
/* MS: test function trace if is taken or not */
lwi r20, r0, ftrace_trace_function;
addik r6, r0, ftrace_stub;
cmpu r5, r20, r6; /* ftrace_trace_function != ftrace_stub */
beqid r5, end; /* MS: not taken -> jump over */
nop;
#else /* CONFIG_DYNAMIC_FTRACE */
NOALIGN_ENTRY(ftrace_call)
/* instruction for setup imm FUNC_part1, addik r20, r0, FUNC_part2 */
nop
nop
#endif /* CONFIG_DYNAMIC_FTRACE */
/* static normal trace */
lwi r6, r1, 120; /* MS: load parent addr */
addik r5, r15, 0; /* MS: load current function addr */
/* MS: here is dependency on previous code */
brald r15, r20; /* MS: jump to ftrace handler */
nop;
end:
lwi r15, r1, 0;
RESTORE_REGS
rtsd r15, 8; /* MS: jump back */
nop;
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
ENTRY(return_to_handler)
nop; /* MS: just barrier for rtsd r15, 8 */
nop;
SAVE_REGS
swi r15, r1, 0;
/* MS: find out returning address */
bralid r15, ftrace_return_to_handler;
nop;
/* MS: return value from ftrace_return_to_handler is my returning addr
* must be before restore regs because I have to restore r3 content */
addik r15, r3, 0;
RESTORE_REGS
rtsd r15, 8; /* MS: jump back */
nop;
#endif /* CONFIG_FUNCTION_TRACER */
