From: Salvador Arroyo Date: Tue, 30 Oct 2012 22:15:35 +0000 (+0100) Subject: mips: optimize mips_ejtag_step_disable() code X-Git-Tag: v0.7.0-rc1~159 X-Git-Url: https://review.openocd.org/gitweb?p=openocd.git;a=commitdiff_plain;h=47d5f44fe0401746b3239ea43994889c41c0ca5e mips: optimize mips_ejtag_step_disable() code The code is a bit large compared to mips_ejtag_step_enable(). With the mips32 xori instruction the code can be reused. The number of pracc accesses are reduced from 18 to 7. Change-Id: If3974ebd64da4461c22b089796646990e68e1b72 Signed-off-by: Salvador Arroyo Reviewed-on: http://openocd.zylin.com/944 Tested-by: jenkins Reviewed-by: Spencer Oliver --- diff --git a/src/target/mips32.h b/src/target/mips32.h index a5bccdc24d..0bdfc59607 100644 --- a/src/target/mips32.h +++ b/src/target/mips32.h @@ -144,6 +144,7 @@ struct mips32_algorithm { #define MIPS32_OP_SH 0x29 #define MIPS32_OP_SW 0x2B #define MIPS32_OP_ORI 0x0D +#define MIPS32_OP_XORI 0x0E #define MIPS32_OP_XOR 0x26 #define MIPS32_OP_SLTU 0x2B #define MIPS32_OP_SRL 0x03 @@ -186,6 +187,7 @@ struct mips32_algorithm { #define MIPS32_MTLO(reg) MIPS32_R_INST(0, reg, 0, 0, 0, MIPS32_OP_MTLO) #define MIPS32_MTHI(reg) MIPS32_R_INST(0, reg, 0, 0, 0, MIPS32_OP_MTHI) #define MIPS32_ORI(tar, src, val) MIPS32_I_INST(MIPS32_OP_ORI, src, tar, val) +#define MIPS32_XORI(tar, src, val) MIPS32_I_INST(MIPS32_OP_XORI, src, tar, val) #define MIPS32_RDHWR(tar, dst) MIPS32_R_INST(MIPS32_OP_SPECIAL3, 0, tar, dst, 0, MIPS32_OP_RDHWR) #define MIPS32_SB(reg, off, base) MIPS32_I_INST(MIPS32_OP_SB, base, reg, off) #define MIPS32_SH(reg, off, base) MIPS32_I_INST(MIPS32_OP_SH, base, reg, off) diff --git a/src/target/mips_ejtag.c b/src/target/mips_ejtag.c index 9114f8c4cf..c2bee941d9 100644 --- a/src/target/mips_ejtag.c +++ b/src/target/mips_ejtag.c @@ -190,49 +190,32 @@ void mips_ejtag_drscan_8_out(struct mips_ejtag *ejtag_info, uint8_t data) jtag_add_dr_scan(tap, 1, &field, TAP_IDLE); } -static int mips_ejtag_step_enable(struct mips_ejtag *ejtag_info) +/* Set (to enable) or clear (to disable stepping) the SSt bit (bit 8) in Cp0 Debug reg (reg 23, sel 0) */ +int mips_ejtag_config_step(struct mips_ejtag *ejtag_info, int enable_step) { - static const uint32_t code[] = { - MIPS32_MTC0(1, 31, 0), /* move $1 to COP0 DeSave */ - MIPS32_MFC0(1, 23, 0), /* move COP0 Debug to $1 */ - MIPS32_ORI(1, 1, 0x0100), /* set SSt bit in debug reg */ - MIPS32_MTC0(1, 23, 0), /* move $1 to COP0 Debug */ - MIPS32_B(NEG16(5)), - MIPS32_MFC0(1, 31, 0), /* move COP0 DeSave to $1 */ - }; + int code_len = enable_step ? 6 : 7; - return mips32_pracc_exec(ejtag_info, ARRAY_SIZE(code), code, - 0, NULL, 0, NULL, 1); -} + uint32_t *code = malloc(code_len * sizeof(uint32_t)); + if (code == NULL) { + LOG_ERROR("Out of memory"); + return ERROR_FAIL; + } + uint32_t *code_p = code; -static int mips_ejtag_step_disable(struct mips_ejtag *ejtag_info) -{ - static const uint32_t code[] = { - MIPS32_MTC0(15, 31, 0), /* move $15 to COP0 DeSave */ - MIPS32_LUI(15, UPPER16(MIPS32_PRACC_STACK)), /* $15 = MIPS32_PRACC_STACK */ - MIPS32_ORI(15, 15, LOWER16(MIPS32_PRACC_STACK)), - MIPS32_SW(1, 0, 15), /* sw $1,($15) */ - MIPS32_SW(2, 0, 15), /* sw $2,($15) */ - MIPS32_MFC0(1, 23, 0), /* move COP0 Debug to $1 */ - MIPS32_LUI(2, 0xFFFF), /* $2 = 0xfffffeff */ - MIPS32_ORI(2, 2, 0xFEFF), - MIPS32_AND(1, 1, 2), - MIPS32_MTC0(1, 23, 0), /* move $1 to COP0 Debug */ - MIPS32_LW(2, 0, 15), - MIPS32_LW(1, 0, 15), - MIPS32_B(NEG16(13)), - MIPS32_MFC0(15, 31, 0), /* move COP0 DeSave to $15 */ - }; + *code_p++ = MIPS32_MTC0(1, 31, 0); /* move $1 to COP0 DeSave */ + *code_p++ = MIPS32_MFC0(1, 23, 0), /* move COP0 Debug to $1 */ + *code_p++ = MIPS32_ORI(1, 1, 0x0100); /* set SSt bit in debug reg */ + if (!enable_step) + *code_p++ = MIPS32_XORI(1, 1, 0x0100); /* clear SSt bit in debug reg */ - return mips32_pracc_exec(ejtag_info, ARRAY_SIZE(code), code, - 0, NULL, 0, NULL, 1); -} + *code_p++ = MIPS32_MTC0(1, 23, 0); /* move $1 to COP0 Debug */ + *code_p++ = MIPS32_B(NEG16((code_len - 1))); /* jump to start */ + *code_p = MIPS32_MFC0(1, 31, 0); /* move COP0 DeSave to $1 */ -int mips_ejtag_config_step(struct mips_ejtag *ejtag_info, int enable_step) -{ - if (enable_step) - return mips_ejtag_step_enable(ejtag_info); - return mips_ejtag_step_disable(ejtag_info); + int retval = mips32_pracc_exec(ejtag_info, code_len, code, 0, NULL, 0, NULL, 1); + + free(code); + return retval; } int mips_ejtag_enter_debug(struct mips_ejtag *ejtag_info)