target, flash: prepare infrastructure for multi-block blank check

'flash erase_check' command runs a check algorithm on a target
if possible. The algorithm is run repeatedly for each flash sector.
Unfortunately every start and stop of the algorithm impose not negligible
overhead.
In practice it means checking is faster than plain read only for
sectors of size approx 4 kByte or bigger. And checking sectors
as short as 512 bytes runs approx 4 times slower than plain read.

The patch changes API call target_blank_check_memory() and related
to take an array of sectors (or arbitrary memory blocks).

Changes in target-specific checking routines are kept minimal.
They use only the first block from the array and process it by
the unchanged algorithm.

default_flash_blank_check() routine repeats target_blank_check_memory()
until all blocks are checked, so it works with both multi-block
and single-block based checkers.

Change-Id: I0e6c60f2d71364c9c07c09416b04de9268807f5e
Signed-off-by: Tomas Vanek <vanekt@fbl.cz>
Reviewed-on: http://openocd.zylin.com/4297
Tested-by: jenkins
Reviewed-by: Andreas Bolsch <hyphen0break@gmail.com>

12 files changed, 82 insertions, 95 deletions

diff --git a/src/flash/nor/at91sam7.c b/src/flash/nor/at91sam7.c
index 03f771c..9de8293 100644
--- a/src/flash/nor/at91sam7.c
+++ b/src/flash/nor/at91sam7.c
@@ -639,14 +639,6 @@ static int at91sam7_read_part_info(struct flash_bank *bank)
 
 static int at91sam7_erase_check(struct flash_bank *bank)
 {
-	struct target *target = bank->target;
-	uint16_t retval;
-	uint32_t blank;
-	uint16_t fast_check;
-	uint8_t *buffer;
-	uint16_t nSector;
-	uint16_t nByte;
-
 	if (bank->target->state != TARGET_HALTED) {
 		LOG_ERROR("Target not halted");
 		return ERROR_TARGET_NOT_HALTED;
@@ -656,45 +648,7 @@ static int at91sam7_erase_check(struct flash_bank *bank)
 	at91sam7_read_clock_info(bank);
 	at91sam7_set_flash_mode(bank, FMR_TIMING_FLASH);
 
-	fast_check = 1;
-	for (nSector = 0; nSector < bank->num_sectors; nSector++) {
-		retval = target_blank_check_memory(target,
-				bank->base + bank->sectors[nSector].offset,
-				bank->sectors[nSector].size,
-				&blank, bank->erased_value);
-		if (retval != ERROR_OK) {
-			fast_check = 0;
-			break;
-		}
-		if (blank == 0xFF)
-			bank->sectors[nSector].is_erased = 1;
-		else
-			bank->sectors[nSector].is_erased = 0;
-	}
-
-	if (fast_check)
-		return ERROR_OK;
-
-	LOG_USER("Running slow fallback erase check - add working memory");
-
-	buffer = malloc(bank->sectors[0].size);
-	for (nSector = 0; nSector < bank->num_sectors; nSector++) {
-		bank->sectors[nSector].is_erased = 1;
-		retval = target_read_memory(target, bank->base + bank->sectors[nSector].offset, 4,
-				bank->sectors[nSector].size/4, buffer);
-		if (retval != ERROR_OK)
-			return retval;
-
-		for (nByte = 0; nByte < bank->sectors[nSector].size; nByte++) {
-			if (buffer[nByte] != 0xFF) {
-				bank->sectors[nSector].is_erased = 0;
-				break;
-			}
-		}
-	}
-	free(buffer);
-
-	return ERROR_OK;
+	return default_flash_blank_check(bank);
 }
 
 static int at91sam7_protect_check(struct flash_bank *bank)
diff --git a/src/flash/nor/core.c b/src/flash/nor/core.c
index 636d50c..707dcff 100644
--- a/src/flash/nor/core.c
+++ b/src/flash/nor/core.c
@@ -339,36 +339,49 @@ int default_flash_blank_check(struct flash_bank *bank)
 	struct target *target = bank->target;
 	int i;
 	int retval;
-	int fast_check = 0;
-	uint32_t blank;
 
 	if (bank->target->state != TARGET_HALTED) {
 		LOG_ERROR("Target not halted");
 		return ERROR_TARGET_NOT_HALTED;
 	}
 
+	struct target_memory_check_block *block_array;
+	block_array = malloc(bank->num_sectors * sizeof(struct target_memory_check_block));
+	if (block_array == NULL)
+		return default_flash_mem_blank_check(bank);
+
 	for (i = 0; i < bank->num_sectors; i++) {
-		uint32_t address = bank->base + bank->sectors[i].offset;
-		uint32_t size = bank->sectors[i].size;
+		block_array[i].address = bank->base + bank->sectors[i].offset;
+		block_array[i].size = bank->sectors[i].size;
+		block_array[i].result = UINT32_MAX; /* erase state unknown */
+	}
 
-		retval = target_blank_check_memory(target, address, size, &blank, bank->erased_value);
-		if (retval != ERROR_OK) {
-			fast_check = 0;
+	bool fast_check = true;
+	for (i = 0; i < bank->num_sectors; ) {
+		retval = target_blank_check_memory(target,
+				block_array + i, bank->num_sectors - i,
+				bank->erased_value);
+		if (retval < 1) {
+			/* Run slow fallback if the first run gives no result
+			 * otherwise use possibly incomplete results */
+			if (i == 0)
+				fast_check = false;
 			break;
 		}
-		if (blank == bank->erased_value)
-			bank->sectors[i].is_erased = 1;
-		else
-			bank->sectors[i].is_erased = 0;
-		fast_check = 1;
+		i += retval; /* add number of blocks done this round */
 	}
 
-	if (!fast_check) {
+	if (fast_check) {
+		for (i = 0; i < bank->num_sectors; i++)
+			bank->sectors[i].is_erased = block_array[i].result;
+		retval = ERROR_OK;
+	} else {
 		LOG_USER("Running slow fallback erase check - add working memory");
-		return default_flash_mem_blank_check(bank);
+		retval = default_flash_mem_blank_check(bank);
 	}
+	free(block_array);
 
-	return ERROR_OK;
+	return retval;
 }
 
 /* Manipulate given flash region, selecting the bank according to target
diff --git a/src/target/arm.h b/src/target/arm.h
index 62fbb73..dd25d53 100644
--- a/src/target/arm.h
+++ b/src/target/arm.h
@@ -308,7 +308,7 @@ int armv4_5_run_algorithm_inner(struct target *target,
 int arm_checksum_memory(struct target *target,
 		target_addr_t address, uint32_t count, uint32_t *checksum);
 int arm_blank_check_memory(struct target *target,
-		target_addr_t address, uint32_t count, uint32_t *blank, uint8_t erased_value);
+		struct target_memory_check_block *blocks, int num_blocks, uint8_t erased_value);
 
 void arm_set_cpsr(struct arm *arm, uint32_t cpsr);
 struct reg *arm_reg_current(struct arm *arm, unsigned regnum);
diff --git a/src/target/armv4_5.c b/src/target/armv4_5.c
index a6fadaa..06994ca 100644
--- a/src/target/armv4_5.c
+++ b/src/target/armv4_5.c
@@ -1663,7 +1663,7 @@ cleanup:
  *
  */
 int arm_blank_check_memory(struct target *target,
-	target_addr_t address, uint32_t count, uint32_t *blank, uint8_t erased_value)
+	struct target_memory_check_block *blocks, int num_blocks, uint8_t erased_value)
 {
 	struct working_area *check_algorithm;
 	struct reg_param reg_params[3];
@@ -1706,10 +1706,10 @@ int arm_blank_check_memory(struct target *target,
 	arm_algo.core_state = ARM_STATE_ARM;
 
 	init_reg_param(&reg_params[0], "r0", 32, PARAM_OUT);
-	buf_set_u32(reg_params[0].value, 0, 32, address);
+	buf_set_u32(reg_params[0].value, 0, 32, blocks[0].address);
 
 	init_reg_param(&reg_params[1], "r1", 32, PARAM_OUT);
-	buf_set_u32(reg_params[1].value, 0, 32, count);
+	buf_set_u32(reg_params[1].value, 0, 32, blocks[0].size);
 
 	init_reg_param(&reg_params[2], "r2", 32, PARAM_IN_OUT);
 	buf_set_u32(reg_params[2].value, 0, 32, erased_value);
@@ -1724,7 +1724,7 @@ int arm_blank_check_memory(struct target *target,
 			10000, &arm_algo);
 
 	if (retval == ERROR_OK)
-		*blank = buf_get_u32(reg_params[2].value, 0, 32);
+		blocks[0].result = buf_get_u32(reg_params[2].value, 0, 32);
 
 	destroy_reg_param(&reg_params[0]);
 	destroy_reg_param(&reg_params[1]);
@@ -1733,7 +1733,10 @@ int arm_blank_check_memory(struct target *target,
 cleanup:
 	target_free_working_area(target, check_algorithm);
 
-	return retval;
+	if (retval != ERROR_OK)
+		return retval;
+
+	return 1;       /* only one block has been checked */
 }
 
 static int arm_full_context(struct target *target)
diff --git a/src/target/armv7m.c b/src/target/armv7m.c
index a8ddfe8..696f85c 100644
--- a/src/target/armv7m.c
+++ b/src/target/armv7m.c
@@ -733,7 +733,7 @@ cleanup:
 
 /** Checks whether a memory region is erased. */
 int armv7m_blank_check_memory(struct target *target,
-	target_addr_t address, uint32_t count, uint32_t *blank, uint8_t erased_value)
+	struct target_memory_check_block *blocks, int num_blocks, uint8_t erased_value)
 {
 	struct working_area *erase_check_algorithm;
 	struct reg_param reg_params[3];
@@ -774,10 +774,10 @@ int armv7m_blank_check_memory(struct target *target,
 	armv7m_info.core_mode = ARM_MODE_THREAD;
 
 	init_reg_param(&reg_params[0], "r0", 32, PARAM_OUT);
-	buf_set_u32(reg_params[0].value, 0, 32, address);
+	buf_set_u32(reg_params[0].value, 0, 32, blocks->address);
 
 	init_reg_param(&reg_params[1], "r1", 32, PARAM_OUT);
-	buf_set_u32(reg_params[1].value, 0, 32, count);
+	buf_set_u32(reg_params[1].value, 0, 32, blocks->size);
 
 	init_reg_param(&reg_params[2], "r2", 32, PARAM_IN_OUT);
 	buf_set_u32(reg_params[2].value, 0, 32, erased_value);
@@ -793,7 +793,7 @@ int armv7m_blank_check_memory(struct target *target,
 			&armv7m_info);
 
 	if (retval == ERROR_OK)
-		*blank = buf_get_u32(reg_params[2].value, 0, 32);
+		blocks->result = buf_get_u32(reg_params[2].value, 0, 32);
 
 	destroy_reg_param(&reg_params[0]);
 	destroy_reg_param(&reg_params[1]);
@@ -802,7 +802,10 @@ int armv7m_blank_check_memory(struct target *target,
 cleanup:
 	target_free_working_area(target, erase_check_algorithm);
 
-	return retval;
+	if (retval != ERROR_OK)
+		return retval;
+
+	return 1;	/* only one block checked */
 }
 
 int armv7m_maybe_skip_bkpt_inst(struct target *target, bool *inst_found)
diff --git a/src/target/armv7m.h b/src/target/armv7m.h
index 6f5d6f9..01bf19e 100644
--- a/src/target/armv7m.h
+++ b/src/target/armv7m.h
@@ -225,7 +225,7 @@ int armv7m_restore_context(struct target *target);
 int armv7m_checksum_memory(struct target *target,
 		target_addr_t address, uint32_t count, uint32_t *checksum);
 int armv7m_blank_check_memory(struct target *target,
-		target_addr_t address, uint32_t count, uint32_t *blank, uint8_t erased_value);
+		struct target_memory_check_block *blocks, int num_blocks, uint8_t erased_value);
 
 int armv7m_maybe_skip_bkpt_inst(struct target *target, bool *inst_found);
 
diff --git a/src/target/mips32.c b/src/target/mips32.c
index 93fb4e6..b5dbea3 100644
--- a/src/target/mips32.c
+++ b/src/target/mips32.c
@@ -827,7 +827,8 @@ int mips32_checksum_memory(struct target *target, target_addr_t address,
 
 /** Checks whether a memory region is erased. */
 int mips32_blank_check_memory(struct target *target,
-		target_addr_t address, uint32_t count, uint32_t *blank, uint8_t erased_value)
+		struct target_memory_check_block *blocks, int num_blocks,
+		uint8_t erased_value)
 {
 	struct working_area *erase_check_algorithm;
 	struct reg_param reg_params[3];
@@ -866,16 +867,16 @@ int mips32_blank_check_memory(struct target *target,
 	int retval = target_write_buffer(target, erase_check_algorithm->address,
 						sizeof(erase_check_code), erase_check_code_8);
 	if (retval != ERROR_OK)
-		return retval;
+		goto cleanup;
 
 	mips32_info.common_magic = MIPS32_COMMON_MAGIC;
 	mips32_info.isa_mode = isa ? MIPS32_ISA_MMIPS32 : MIPS32_ISA_MIPS32;
 
 	init_reg_param(&reg_params[0], "r4", 32, PARAM_OUT);
-	buf_set_u32(reg_params[0].value, 0, 32, address);
+	buf_set_u32(reg_params[0].value, 0, 32, blocks[0].address);
 
 	init_reg_param(&reg_params[1], "r5", 32, PARAM_OUT);
-	buf_set_u32(reg_params[1].value, 0, 32, count);
+	buf_set_u32(reg_params[1].value, 0, 32, blocks[0].size);
 
 	init_reg_param(&reg_params[2], "r6", 32, PARAM_IN_OUT);
 	buf_set_u32(reg_params[2].value, 0, 32, erased_value);
@@ -884,15 +885,19 @@ int mips32_blank_check_memory(struct target *target,
 			erase_check_algorithm->address + (sizeof(erase_check_code) - 4), 10000, &mips32_info);
 
 	if (retval == ERROR_OK)
-		*blank = buf_get_u32(reg_params[2].value, 0, 32);
+		blocks[0].result = buf_get_u32(reg_params[2].value, 0, 32);
 
 	destroy_reg_param(&reg_params[0]);
 	destroy_reg_param(&reg_params[1]);
 	destroy_reg_param(&reg_params[2]);
 
+cleanup:
 	target_free_working_area(target, erase_check_algorithm);
 
-	return retval;
+	if (retval != ERROR_OK)
+		return retval;
+
+	return 1;       /* only one block has been checked */
 }
 
 static int mips32_verify_pointer(struct command_context *cmd_ctx,
diff --git a/src/target/mips32.h b/src/target/mips32.h
index 928598f..4dc164e 100644
--- a/src/target/mips32.h
+++ b/src/target/mips32.h
@@ -428,6 +428,6 @@ int mips32_get_gdb_reg_list(struct target *target,
 int mips32_checksum_memory(struct target *target, target_addr_t address,
 		uint32_t count, uint32_t *checksum);
 int mips32_blank_check_memory(struct target *target,
-		target_addr_t address, uint32_t count, uint32_t *blank, uint8_t erased_value);
+		struct target_memory_check_block *blocks, int num_blocks, uint8_t erased_value);
 
 #endif /* OPENOCD_TARGET_MIPS32_H */
diff --git a/src/target/stm8.c b/src/target/stm8.c
index 4556fd9..5a3438a 100644
--- a/src/target/stm8.c
+++ b/src/target/stm8.c
@@ -1750,7 +1750,7 @@ static int stm8_examine(struct target *target)
 
 /** Checks whether a memory region is erased. */
 static int stm8_blank_check_memory(struct target *target,
-		target_addr_t address, uint32_t count, uint32_t *blank, uint8_t erased_value)
+		struct target_memory_check_block *blocks, int num_blocks, uint8_t erased_value)
 {
 	struct working_area *erase_check_algorithm;
 	struct reg_param reg_params[2];
@@ -1778,10 +1778,10 @@ static int stm8_blank_check_memory(struct target *target,
 	stm8_info.common_magic = STM8_COMMON_MAGIC;
 
 	init_mem_param(&mem_params[0], 0x0, 3, PARAM_OUT);
-	buf_set_u32(mem_params[0].value, 0, 24, address);
+	buf_set_u32(mem_params[0].value, 0, 24, blocks[0].address);
 
 	init_mem_param(&mem_params[1], 0x3, 3, PARAM_OUT);
-	buf_set_u32(mem_params[1].value, 0, 24, count);
+	buf_set_u32(mem_params[1].value, 0, 24, blocks[0].size);
 
 	init_reg_param(&reg_params[0], "a", 32, PARAM_IN_OUT);
 	buf_set_u32(reg_params[0].value, 0, 32, erased_value);
@@ -1795,7 +1795,7 @@ static int stm8_blank_check_memory(struct target *target,
 			10000, &stm8_info);
 
 	if (retval == ERROR_OK)
-		*blank = (*(reg_params[0].value) == 0xff);
+		blocks[0].result = (*(reg_params[0].value) == 0xff);
 
 	destroy_mem_param(&mem_params[0]);
 	destroy_mem_param(&mem_params[1]);
@@ -1803,7 +1803,10 @@ static int stm8_blank_check_memory(struct target *target,
 
 	target_free_working_area(target, erase_check_algorithm);
 
-	return retval;
+	if (retval != ERROR_OK)
+		return retval;
+
+	return 1;	/* only one block has been checked */
 }
 
 static int stm8_checksum_memory(struct target *target, target_addr_t address,
diff --git a/src/target/target.c b/src/target/target.c
index 729a31b..75555c1 100644
--- a/src/target/target.c
+++ b/src/target/target.c
@@ -2251,21 +2251,19 @@ int target_checksum_memory(struct target *target, target_addr_t address, uint32_
 	return retval;
 }
 
-int target_blank_check_memory(struct target *target, target_addr_t address, uint32_t size, uint32_t* blank,
+int target_blank_check_memory(struct target *target,
+	struct target_memory_check_block *blocks, int num_blocks,
 	uint8_t erased_value)
 {
-	int retval;
 	if (!target_was_examined(target)) {
 		LOG_ERROR("Target not examined yet");
 		return ERROR_FAIL;
 	}
 
-	if (target->type->blank_check_memory == 0)
+	if (target->type->blank_check_memory == NULL)
 		return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
 
-	retval = target->type->blank_check_memory(target, address, size, blank, erased_value);
-
-	return retval;
+	return target->type->blank_check_memory(target, blocks, num_blocks, erased_value);
 }
 
 int target_read_u64(struct target *target, target_addr_t address, uint64_t *value)
diff --git a/src/target/target.h b/src/target/target.h
index 7a8a80f..c5fb55b 100644
--- a/src/target/target.h
+++ b/src/target/target.h
@@ -312,6 +312,12 @@ struct target_timer_callback {
 	struct target_timer_callback *next;
 };
 
+struct target_memory_check_block {
+	target_addr_t address;
+	uint32_t size;
+	uint32_t result;
+};
+
 int target_register_commands(struct command_context *cmd_ctx);
 int target_examine(void);
 
@@ -585,7 +591,8 @@ int target_read_buffer(struct target *target,
 int target_checksum_memory(struct target *target,
 		target_addr_t address, uint32_t size, uint32_t *crc);
 int target_blank_check_memory(struct target *target,
-		target_addr_t address, uint32_t size, uint32_t *blank, uint8_t erased_value);
+		struct target_memory_check_block *blocks, int num_blocks,
+		uint8_t erased_value);
 int target_wait_state(struct target *target, enum target_state state, int ms);
 
 /**
diff --git a/src/target/target_type.h b/src/target/target_type.h
index 0ab22bd..fbbd57d 100644
--- a/src/target/target_type.h
+++ b/src/target/target_type.h
@@ -130,8 +130,9 @@ struct target_type {
 
 	int (*checksum_memory)(struct target *target, target_addr_t address,
 			uint32_t count, uint32_t *checksum);
-	int (*blank_check_memory)(struct target *target, target_addr_t address,
-			uint32_t count, uint32_t *blank, uint8_t erased_value);
+	int (*blank_check_memory)(struct target *target,
+			struct target_memory_check_block *blocks, int num_blocks,
+			uint8_t erased_value);
 
 	/*
 	 * target break-/watchpoint control