From 3377c164204f8cdaeabdbba13513091b5e04fce0 Mon Sep 17 00:00:00 2001 From: Andreas Fritiofson Date: Wed, 13 Mar 2013 23:41:04 +0100 Subject: [PATCH] target: Rewrite read/write buffer default implementations Rewrite the target_*_buffer_default to generate as large accesses as possible while maintaining natural alignment. These versions are easy to extend to generate 8-byte accesses to support 64-bit targets, although it requires some conformity from all target implementations (i.e. they need to refuse unsupported access sizes with some defined error code, so we can try again with a smaller one). Change-Id: I00ddcbb1d2fd33f9f8b99cb448cc93505a2421fc Signed-off-by: Andreas Fritiofson Reviewed-on: http://openocd.zylin.com/1221 Tested-by: jenkins Reviewed-by: Spencer Oliver --- src/target/target.c | 139 ++++++++++++++++---------------------------- 1 file changed, 51 insertions(+), 88 deletions(-) diff --git a/src/target/target.c b/src/target/target.c index 6aee0983..d34e1441 100644 --- a/src/target/target.c +++ b/src/target/target.c @@ -60,9 +60,9 @@ #define DEFAULT_HALT_TIMEOUT 5000 static int target_read_buffer_default(struct target *target, uint32_t address, - uint32_t size, uint8_t *buffer); + uint32_t count, uint8_t *buffer); static int target_write_buffer_default(struct target *target, uint32_t address, - uint32_t size, const uint8_t *buffer); + uint32_t count, const uint8_t *buffer); static int target_array2mem(Jim_Interp *interp, struct target *target, int argc, Jim_Obj * const *argv); static int target_mem2array(Jim_Interp *interp, struct target *target, @@ -1766,50 +1766,37 @@ int target_write_buffer(struct target *target, uint32_t address, uint32_t size, return target->type->write_buffer(target, address, size, buffer); } -static int target_write_buffer_default(struct target *target, uint32_t address, uint32_t size, const uint8_t *buffer) +static int target_write_buffer_default(struct target *target, uint32_t address, uint32_t count, const uint8_t *buffer) { - int retval = ERROR_OK; - - if (((address % 2) == 0) && (size == 2)) - return target_write_memory(target, address, 2, 1, buffer); - - /* handle unaligned head bytes */ - if (address % 4) { - uint32_t unaligned = 4 - (address % 4); - - if (unaligned > size) - unaligned = size; - - retval = target_write_memory(target, address, 1, unaligned, buffer); - if (retval != ERROR_OK) - return retval; - - buffer += unaligned; - address += unaligned; - size -= unaligned; - } - - /* handle aligned words */ - if (size >= 4) { - int aligned = size - (size % 4); - - retval = target_write_memory(target, address, 4, aligned / 4, buffer); - if (retval != ERROR_OK) - return retval; + uint32_t size; - buffer += aligned; - address += aligned; - size -= aligned; + /* Align up to maximum 4 bytes. The loop condition makes sure the next pass + * will have something to do with the size we leave to it. */ + for (size = 1; size < 4 && count >= size * 2 + (address & size); size *= 2) { + if (address & size) { + int retval = target_write_memory(target, address, size, 1, buffer); + if (retval != ERROR_OK) + return retval; + address += size; + count -= size; + buffer += size; + } } - /* handle tail writes of less than 4 bytes */ - if (size > 0) { - retval = target_write_memory(target, address, 1, size, buffer); - if (retval != ERROR_OK) - return retval; + /* Write the data with as large access size as possible. */ + for (; size > 0; size /= 2) { + uint32_t aligned = count - count % size; + if (aligned > 0) { + int retval = target_write_memory(target, address, size, aligned / size, buffer); + if (retval != ERROR_OK) + return retval; + address += aligned; + count -= aligned; + buffer += aligned; + } } - return retval; + return ERROR_OK; } /* Single aligned words are guaranteed to use 16 or 32 bit access @@ -1840,58 +1827,34 @@ int target_read_buffer(struct target *target, uint32_t address, uint32_t size, u return target->type->read_buffer(target, address, size, buffer); } -static int target_read_buffer_default(struct target *target, uint32_t address, uint32_t size, uint8_t *buffer) +static int target_read_buffer_default(struct target *target, uint32_t address, uint32_t count, uint8_t *buffer) { - int retval = ERROR_OK; + uint32_t size; - if (((address % 2) == 0) && (size == 2)) - return target_read_memory(target, address, 2, 1, buffer); - - /* handle unaligned head bytes */ - if (address % 4) { - uint32_t unaligned = 4 - (address % 4); - - if (unaligned > size) - unaligned = size; - - retval = target_read_memory(target, address, 1, unaligned, buffer); - if (retval != ERROR_OK) - return retval; - - buffer += unaligned; - address += unaligned; - size -= unaligned; - } - - /* handle aligned words */ - if (size >= 4) { - int aligned = size - (size % 4); - - retval = target_read_memory(target, address, 4, aligned / 4, buffer); - if (retval != ERROR_OK) - return retval; - - buffer += aligned; - address += aligned; - size -= aligned; + /* Align up to maximum 4 bytes. The loop condition makes sure the next pass + * will have something to do with the size we leave to it. */ + for (size = 1; size < 4 && count >= size * 2 + (address & size); size *= 2) { + if (address & size) { + int retval = target_read_memory(target, address, size, 1, buffer); + if (retval != ERROR_OK) + return retval; + address += size; + count -= size; + buffer += size; + } } - /*prevent byte access when possible (avoid AHB access limitations in some cases)*/ - if (size >= 2) { - int aligned = size - (size % 2); - retval = target_read_memory(target, address, 2, aligned / 2, buffer); - if (retval != ERROR_OK) - return retval; - - buffer += aligned; - address += aligned; - size -= aligned; - } - /* handle tail writes of less than 4 bytes */ - if (size > 0) { - retval = target_read_memory(target, address, 1, size, buffer); - if (retval != ERROR_OK) - return retval; + /* Read the data with as large access size as possible. */ + for (; size > 0; size /= 2) { + uint32_t aligned = count - count % size; + if (aligned > 0) { + int retval = target_read_memory(target, address, size, aligned / size, buffer); + if (retval != ERROR_OK) + return retval; + address += aligned; + count -= aligned; + buffer += aligned; + } } return ERROR_OK; -- 2.39.5