mips: optimize read code for speed

Really nothing new that not explained in previous patches.
The code is expanded as needed, there are no loops in pracc code.
For the first value pracc accesses are reduced from 39 to 16
and for aditional values from 10 to 3.
dump_image should work around 3x faster.

Change-Id: I37c9b13395c09eb52a91f10cdb6cbaedef8ab98b
Signed-off-by: Salvador Arroyo <sarroyofdez@yahoo.es>
Reviewed-on: http://openocd.zylin.com/955
Tested-by: jenkins
Reviewed-by: Spencer Oliver <spen@spen-soft.co.uk>

1 files changed, 82 insertions, 227 deletions

diff --git a/src/target/mips32_pracc.c b/src/target/mips32_pracc.c
index 72effb8e..3ac29495 100644
--- a/src/target/mips32_pracc.c
+++ b/src/target/mips32_pracc.c
@@ -93,12 +93,6 @@ struct mips32_pracc_context {
 	struct mips_ejtag *ejtag_info;
 };
 
-static int mips32_pracc_read_mem8(struct mips_ejtag *ejtag_info,
-		uint32_t addr, int count, uint8_t *buf);
-static int mips32_pracc_read_mem16(struct mips_ejtag *ejtag_info,
-		uint32_t addr, int count, uint16_t *buf);
-static int mips32_pracc_read_mem32(struct mips_ejtag *ejtag_info,
-		uint32_t addr, int count, uint32_t *buf);
 static int mips32_pracc_read_u32(struct mips_ejtag *ejtag_info,
 		uint32_t addr, uint32_t *buf);
 
@@ -294,86 +288,102 @@ int mips32_pracc_exec(struct mips_ejtag *ejtag_info, int code_len, const uint32_
 
 int mips32_pracc_read_mem(struct mips_ejtag *ejtag_info, uint32_t addr, int size, int count, void *buf)
 {
-	switch (size) {
-		case 1:
-			return mips32_pracc_read_mem8(ejtag_info, addr, count, (uint8_t *)buf);
-		case 2:
-			return mips32_pracc_read_mem16(ejtag_info, addr, count, (uint16_t *)buf);
-		case 4:
-			if (count == 1)
-				return mips32_pracc_read_u32(ejtag_info, addr, (uint32_t *)buf);
-			else
-				return mips32_pracc_read_mem32(ejtag_info, addr, count, (uint32_t *)buf);
-	}
+	if (count == 1 && size == 4)
+		return mips32_pracc_read_u32(ejtag_info, addr, (uint32_t *)buf);
 
-	return ERROR_OK;
-}
+	int retval = ERROR_FAIL;
 
-static int mips32_pracc_read_mem32(struct mips_ejtag *ejtag_info, uint32_t addr, int count, uint32_t *buf)
-{
-	static const uint32_t code[] = {
-															/* start: */
-		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(8, 0, 15),								/* sw $8,($15) */
-		MIPS32_SW(9, 0, 15),								/* sw $9,($15) */
-		MIPS32_SW(10, 0, 15),								/* sw $10,($15) */
-		MIPS32_SW(11, 0, 15),								/* sw $11,($15) */
+	uint32_t *code = NULL;
+	uint32_t *data = NULL;
 
-		MIPS32_LUI(8, UPPER16(MIPS32_PRACC_PARAM_IN)),		/* $8 = MIPS32_PRACC_PARAM_IN */
-		MIPS32_ORI(8, 8, LOWER16(MIPS32_PRACC_PARAM_IN)),
-		MIPS32_LW(9, 0, 8),									/* $9 = mem[$8]; read addr */
-		MIPS32_LW(10, 4, 8),								/* $10 = mem[$8 + 4]; read count */
-		MIPS32_LUI(11, UPPER16(MIPS32_PRACC_PARAM_OUT)),	/* $11 = MIPS32_PRACC_PARAM_OUT */
-		MIPS32_ORI(11, 11, LOWER16(MIPS32_PRACC_PARAM_OUT)),
-															/* loop: */
-		MIPS32_BEQ(0, 10, 8),								/* beq 0, $10, end */
-		MIPS32_NOP,
+	code = malloc((256 * 2 + 10) * sizeof(uint32_t));
+	if (code == NULL) {
+		LOG_ERROR("Out of memory");
+		goto exit;
+	}
 
-		MIPS32_LW(8, 0, 9),									/* lw $8,0($9), Load $8 with the word @mem[$9] */
-		MIPS32_SW(8, 0, 11),								/* sw $8,0($11) */
+	if (size != 4) {
+		data = malloc(256 * sizeof(uint32_t));
+		if (data == NULL) {
+			LOG_ERROR("Out of memory");
+			goto exit;
+		}
+	}
 
-		MIPS32_ADDI(10, 10, NEG16(1)),						/* $10-- */
-		MIPS32_ADDI(9, 9, 4),								/* $1 += 4 */
-		MIPS32_ADDI(11, 11, 4),								/* $11 += 4 */
+	uint32_t *buf32 = buf;
+	uint16_t *buf16 = buf;
+	uint8_t *buf8 = buf;
 
-		MIPS32_B(NEG16(8)),									/* b loop */
-		MIPS32_NOP,
-															/* end: */
-		MIPS32_LW(11, 0, 15),								/* lw $11,($15) */
-		MIPS32_LW(10, 0, 15),								/* lw $10,($15) */
-		MIPS32_LW(9, 0, 15),								/* lw $9,($15) */
-		MIPS32_LW(8, 0, 15),								/* lw $8,($15) */
-		MIPS32_B(NEG16(27)),								/* b start */
-		MIPS32_MFC0(15, 31, 0),								/* move COP0 DeSave to $15 */
-	};
+	int i;
+	uint32_t upper_base_addr, last_upper_base_addr;
+	int this_round_count;
+	int code_len;
 
-	int retval = ERROR_OK;
-	int blocksize;
-	int wordsread;
-	uint32_t param_in[2];
+	while (count) {
+		this_round_count = (count > 256) ? 256 : count;
+		last_upper_base_addr = UPPER16((addr + 0x8000));
+		uint32_t *code_p = code;
+
+		*code_p++ = MIPS32_MTC0(15, 31, 0);					/* save $15 in DeSave */
+		*code_p++ = MIPS32_LUI(15, PRACC_UPPER_BASE_ADDR);			/* $15 = MIPS32_PRACC_BASE_ADDR */
+		*code_p++ = MIPS32_SW(8, PRACC_STACK_OFFSET, 15);			/* save $8 and $9 to pracc stack */
+		*code_p++ = MIPS32_SW(9, PRACC_STACK_OFFSET, 15);
+		*code_p++ = MIPS32_LUI(9, last_upper_base_addr);			/* load the upper memory address in $9*/
+		code_len = 5;
+
+		for (i = 0; i != this_round_count; i++) {		/* Main code loop */
+			upper_base_addr = UPPER16((addr + 0x8000));
+			if (last_upper_base_addr != upper_base_addr) {
+				*code_p++ = MIPS32_LUI(9, upper_base_addr);		/* if needed, change upper address in $9*/
+				code_len++;
+				last_upper_base_addr = upper_base_addr;
+			}
+
+			if (size == 4)
+				*code_p++ = MIPS32_LW(8, LOWER16(addr), 9);		/* load from memory to $8 */
+			else if (size == 2)
+				*code_p++ = MIPS32_LHU(8, LOWER16(addr), 9);
+			else
+				*code_p++ = MIPS32_LBU(8, LOWER16(addr), 9);
 
-	wordsread = 0;
+			*code_p++ = MIPS32_SW(8, PRACC_OUT_OFFSET + i * 4, 15);		/* store $8 at param out */
 
-	while (count > 0) {
-		blocksize = count;
-		if (count > 0x400)
-			blocksize = 0x400;
+			code_len += 2;
+			addr += size;
+		}
 
-		param_in[0] = addr;
-		param_in[1] = blocksize;
+		*code_p++ = MIPS32_LW(9, PRACC_STACK_OFFSET, 15);			/* restore $8 and $9 from pracc stack */
+		*code_p++ = MIPS32_LW(8, PRACC_STACK_OFFSET, 15);
 
-		retval = mips32_pracc_exec(ejtag_info, ARRAY_SIZE(code), code,
-				ARRAY_SIZE(param_in), param_in, blocksize, &buf[wordsread], 1);
-		if (retval != ERROR_OK)
-			return retval;
+		code_len += 4;
+		*code_p++ = MIPS32_B(NEG16(code_len - 1));					/* jump to start */
+		*code_p = MIPS32_MFC0(15, 31, 0);					/* restore $15 from DeSave */
 
-		count -= blocksize;
-		addr += blocksize*sizeof(uint32_t);
-		wordsread += blocksize;
+		if (size == 4) {
+			retval = mips32_pracc_exec(ejtag_info, code_len, code, 0, NULL, this_round_count, buf32, 1);
+			if (retval != ERROR_OK)
+				goto exit;
+			buf32 += this_round_count;
+		} else {
+			retval = mips32_pracc_exec(ejtag_info, code_len, code, 0, NULL, this_round_count, data, 1);
+			if (retval != ERROR_OK)
+				goto exit;
+			uint32_t *data_p = data;
+			for (i = 0; i != this_round_count; i++) {
+				if (size == 2)
+					*buf16++ = *data_p++;
+				else
+					*buf8++ = *data_p++;
+			}
+		}
+		count -= this_round_count;
 	}
 
+exit:
+	if (code)
+		free(code);
+	if (data)
+		free(data);
 	return retval;
 }
 
@@ -397,161 +407,6 @@ static int mips32_pracc_read_u32(struct mips_ejtag *ejtag_info, uint32_t addr, u
 	return mips32_pracc_exec(ejtag_info, ARRAY_SIZE(code), code, 0, NULL, 1, buf, 1);
 }
 
-static int mips32_pracc_read_mem16(struct mips_ejtag *ejtag_info, uint32_t addr, int count, uint16_t *buf)
-{
-	static const uint32_t code[] = {
-															/* start: */
-		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(8, 0, 15),								/* sw $8,($15) */
-		MIPS32_SW(9, 0, 15),								/* sw $9,($15) */
-		MIPS32_SW(10, 0, 15),								/* sw $10,($15) */
-		MIPS32_SW(11, 0, 15),								/* sw $11,($15) */
-
-		MIPS32_LUI(8, UPPER16(MIPS32_PRACC_PARAM_IN)),		/* $8 = MIPS32_PRACC_PARAM_IN */
-		MIPS32_ORI(8, 8, LOWER16(MIPS32_PRACC_PARAM_IN)),
-		MIPS32_LW(9, 0, 8),									/* $9 = mem[$8]; read addr */
-		MIPS32_LW(10, 4, 8),								/* $10 = mem[$8 + 4]; read count */
-		MIPS32_LUI(11, UPPER16(MIPS32_PRACC_PARAM_OUT)),	/* $11 = MIPS32_PRACC_PARAM_OUT */
-		MIPS32_ORI(11, 11, LOWER16(MIPS32_PRACC_PARAM_OUT)),
-															/* loop: */
-		MIPS32_BEQ(0, 10, 8),								/* beq 0, $10, end */
-		MIPS32_NOP,
-
-		MIPS32_LHU(8, 0, 9),								/* lw $8,0($9), Load $8 with the halfword @mem[$9] */
-		MIPS32_SW(8, 0, 11),								/* sw $8,0($11) */
-
-		MIPS32_ADDI(10, 10, NEG16(1)),						/* $10-- */
-		MIPS32_ADDI(9, 9, 2),								/* $9 += 2 */
-		MIPS32_ADDI(11, 11, 4),								/* $11 += 4 */
-		MIPS32_B(NEG16(8)),									/* b loop */
-		MIPS32_NOP,
-															/* end: */
-		MIPS32_LW(11, 0, 15),								/* lw $11,($15) */
-		MIPS32_LW(10, 0, 15),								/* lw $10,($15) */
-		MIPS32_LW(9, 0, 15),								/* lw $9,($15) */
-		MIPS32_LW(8, 0, 15),								/* lw $8,($15) */
-		MIPS32_B(NEG16(27)),								/* b start */
-		MIPS32_MFC0(15, 30, 0),								/* move COP0 DeSave to $15 */
-	};
-
-	/* TODO remove array */
-	uint32_t *param_out = malloc(count * sizeof(uint32_t));
-	if (param_out == NULL) {
-		LOG_ERROR("Out of memory");
-		return ERROR_FAIL;
-	}
-
-	int retval = ERROR_OK;
-	int blocksize;
-	int hwordsread = 0;
-	uint32_t param_in[2];
-
-	while (count > 0) {
-		blocksize = count;
-		if (count > 0x400)
-			blocksize = 0x400;
-
-		param_in[0] = addr;
-		param_in[1] = blocksize;
-
-		retval = mips32_pracc_exec(ejtag_info, ARRAY_SIZE(code), code,
-			ARRAY_SIZE(param_in), param_in, blocksize, &param_out[hwordsread], 1);
-
-		if (retval != ERROR_OK)
-			return retval;
-
-		count -= blocksize;
-		addr += blocksize*sizeof(uint16_t);
-		hwordsread += blocksize;
-	}
-
-	int i;
-	for (i = 0; i < hwordsread; i++)
-		buf[i] = param_out[i];
-
-	free(param_out);
-	return retval;
-}
-
-static int mips32_pracc_read_mem8(struct mips_ejtag *ejtag_info, uint32_t addr, int count, uint8_t *buf)
-{
-	static const uint32_t code[] = {
-															/* start: */
-		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(8, 0, 15),								/* sw $8,($15) */
-		MIPS32_SW(9, 0, 15),								/* sw $9,($15) */
-		MIPS32_SW(10, 0, 15),								/* sw $10,($15) */
-		MIPS32_SW(11, 0, 15),								/* sw $11,($15) */
-
-		MIPS32_LUI(8, UPPER16(MIPS32_PRACC_PARAM_IN)),		/* $8 = MIPS32_PRACC_PARAM_IN */
-		MIPS32_ORI(8, 8, LOWER16(MIPS32_PRACC_PARAM_IN)),
-		MIPS32_LW(9, 0, 8),									/* $9 = mem[$8]; read addr */
-		MIPS32_LW(10, 4, 8),								/* $10 = mem[$8 + 4]; read count */
-		MIPS32_LUI(11, UPPER16(MIPS32_PRACC_PARAM_OUT)),	/* $11 = MIPS32_PRACC_PARAM_OUT */
-		MIPS32_ORI(11, 11, LOWER16(MIPS32_PRACC_PARAM_OUT)),
-															/* loop: */
-		MIPS32_BEQ(0, 10, 8),								/* beq 0, $10, end */
-		MIPS32_NOP,
-
-		MIPS32_LBU(8, 0, 9),								/* lw $8,0($9), Load t4 with the byte @mem[t1] */
-		MIPS32_SW(8, 0, 11),								/* sw $8,0($11) */
-
-		MIPS32_ADDI(10, 10, NEG16(1)),						/* $10-- */
-		MIPS32_ADDI(9, 9, 1),								/* $9 += 1 */
-		MIPS32_ADDI(11, 11, 4),								/* $11 += 4 */
-		MIPS32_B(NEG16(8)),									/* b loop */
-		MIPS32_NOP,
-															/* end: */
-		MIPS32_LW(11, 0, 15),								/* lw $11,($15) */
-		MIPS32_LW(10, 0, 15),								/* lw $10,($15) */
-		MIPS32_LW(9, 0, 15),								/* lw $9,($15) */
-		MIPS32_LW(8, 0, 15),								/* lw $8,($15) */
-		MIPS32_B(NEG16(27)),								/* b start */
-		MIPS32_MFC0(15, 31, 0),								/* move COP0 DeSave to $15 */
-	};
-
-	/* TODO remove array */
-	uint32_t *param_out = malloc(count * sizeof(uint32_t));
-	if (param_out == NULL) {
-		LOG_ERROR("Out of memory");
-		return ERROR_FAIL;
-	}
-
-	int retval = ERROR_OK;
-	int blocksize;
-	uint32_t param_in[2];
-	int bytesread = 0;
-
-	while (count > 0) {
-		blocksize = count;
-		if (count > 0x400)
-			blocksize = 0x400;
-
-		param_in[0] = addr;
-		param_in[1] = blocksize;
-
-		retval = mips32_pracc_exec(ejtag_info, ARRAY_SIZE(code), code,
-			ARRAY_SIZE(param_in), param_in, count, &param_out[bytesread], 1);
-
-		if (retval != ERROR_OK)
-			return retval;
-
-		count -= blocksize;
-		addr += blocksize;
-		bytesread += blocksize;
-	}
-	int i;
-	for (i = 0; i < bytesread; i++)
-		buf[i] = param_out[i];
-
-	free(param_out);
-	return retval;
-}
-
 int mips32_cp0_read(struct mips_ejtag *ejtag_info, uint32_t *val, uint32_t cp0_reg, uint32_t cp0_sel)
 {
 	/**