From 4d6829f92a02d96e1bec2ffe6ee674ef3b49722b Mon Sep 17 00:00:00 2001 From: Wu Zhangjin Date: Fri, 14 May 2010 19:08:31 +0800 Subject: [PATCH] MIPS: Tracing: Cleanup of instructions used This patch adds some cleanups of the instructions: o use macros instead of magic numbers o use macros instead of variables to reduce some overhead o add new macro for the jal instruction Signed-off-by: Wu Zhangjin Cc: linux-mips Cc: David Daney Patchwork: http://patchwork.linux-mips.org/patch/1229/ Signed-off-by: Ralf Baechle --- arch/mips/kernel/ftrace.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/arch/mips/kernel/ftrace.c b/arch/mips/kernel/ftrace.c index 37aa7677e76..b1b8fec2432 100644 --- a/arch/mips/kernel/ftrace.c +++ b/arch/mips/kernel/ftrace.c @@ -23,7 +23,10 @@ #define jump_insn_encode(op_code, addr) \ ((unsigned int)((op_code) | (((addr) >> 2) & ADDR_MASK))) -static unsigned int ftrace_nop = 0x00000000; +#define INSN_B_1F_4 0x10000004 /* b 1f; offset = 4 */ +#define INSN_B_1F_5 0x10000005 /* b 1f; offset = 5 */ +#define INSN_NOP 0x00000000 /* nop */ +#define INSN_JAL(addr) jump_insn_encode(JAL, addr) static int ftrace_modify_code(unsigned long ip, unsigned int new_code) { @@ -71,7 +74,7 @@ int ftrace_make_nop(struct module *mod, * sub sp, sp, 8 * 1: offset = 5 instructions */ - new = 0x10000005; + new = INSN_B_1F_5; #else /* lui v1, hi_16bit_of_mcount --> b 1f (0x10000004) * addiu v1, v1, low_16bit_of_mcount @@ -80,7 +83,7 @@ int ftrace_make_nop(struct module *mod, * nop | move $12, ra_address | sub sp, sp, 8 * 1: offset = 4 instructions */ - new = 0x10000004; + new = INSN_B_1F_4; #endif } else { /* record/calculate it for ftrace_make_call */ @@ -88,13 +91,13 @@ int ftrace_make_nop(struct module *mod, /* We can record it directly like this: * jal_mcount = *(unsigned int *)ip; * Herein, jump over the first two nop instructions */ - jal_mcount = jump_insn_encode(JAL, (MCOUNT_ADDR + 8)); + jal_mcount = INSN_JAL(MCOUNT_ADDR + 8); } /* move at, ra * jalr v1 --> nop */ - new = ftrace_nop; + new = INSN_NOP; } return ftrace_modify_code(ip, new); } @@ -109,7 +112,7 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) /* We just need to remove the "b ftrace_stub" at the fist time! */ if (modified == 0) { modified = 1; - ftrace_modify_code(addr, ftrace_nop); + ftrace_modify_code(addr, INSN_NOP); } /* ip, module: 0xc0000000, kernel: 0x80000000 */ new = (ip & 0x40000000) ? lui_v1 : jal_mcount; @@ -123,7 +126,7 @@ int ftrace_update_ftrace_func(ftrace_func_t func) { unsigned int new; - new = jump_insn_encode(JAL, (unsigned long)func); + new = INSN_JAL((unsigned long)func); return ftrace_modify_code(FTRACE_CALL_IP, new); } @@ -155,7 +158,7 @@ int ftrace_enable_ftrace_graph_caller(void) int ftrace_disable_ftrace_graph_caller(void) { - return ftrace_modify_code(FTRACE_GRAPH_CALL_IP, ftrace_nop); + return ftrace_modify_code(FTRACE_GRAPH_CALL_IP, INSN_NOP); } #endif /* !CONFIG_DYNAMIC_FTRACE */ -- 2.39.2