zcy
/
tinyriscv-openocd
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Speed up SBA block reads roughly 2x. (#477) 

* Speed up SBA block reads roughly 2x.

Change-Id: I4e4f5530d4abae7470fd00308361e727904367d2

* Fix whitespace.

Change-Id: I28a1269c489d051560a2455973f9a8574f35f487
riscv
Tim Newsome 2020-05-18 14:43:41 -07:00 committed by GitHub
parent 62af8d3c10
commit 1524487a13
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 49 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

52
src/target/riscv/riscv-013.c
View File

@ -2536,14 +2536,60 @@ static int read_memory_bus_v1(struct target *target, target_addr_t address,
}
}
/* First value has been read, and is waiting for us to issue a DMI read
* to get it. */
static int sbdata[4] = {DMI_SBDATA0, DMI_SBDATA1, DMI_SBDATA2, DMI_SBDATA3};
assert(size <= 16);
target_addr_t next_read = address - 1;
for (uint32_t i = (next_address - address) / size; i < count - 1; i++) {
if (read_memory_bus_word(target, address + i * size, size,
buffer + i * size) != ERROR_OK)
return ERROR_FAIL;
for (int j = (size - 1) / 4; j >= 0; j--) {
uint32_t value;
unsigned attempt = 0;
while (1) {
if (attempt++ > 100) {
LOG_ERROR("DMI keeps being busy in while reading memory just past " TARGET_ADDR_FMT,
next_read);
return ERROR_FAIL;
}
dmi_status_t status = dmi_scan(target, NULL, &value,
DMI_OP_READ, sbdata[j], 0, false);
if (status == DMI_STATUS_BUSY)
increase_dmi_busy_delay(target);
else if (status == DMI_STATUS_SUCCESS)
break;
else
return ERROR_FAIL;
}
if (next_read != address - 1) {
write_to_buf(buffer + next_read - address, value, MIN(size, 4));
log_memory_access(next_read, value, MIN(size, 4), true);
}
next_read = address + i * size + j * 4;
}
}
uint32_t sbcs_read = 0;
if (count > 1) {
uint32_t value;
unsigned attempt = 0;
while (1) {
if (attempt++ > 100) {
LOG_ERROR("DMI keeps being busy in while reading memory just past " TARGET_ADDR_FMT,
next_read);
return ERROR_FAIL;
}
dmi_status_t status = dmi_scan(target, NULL, &value, DMI_OP_NOP, 0, 0, false);
if (status == DMI_STATUS_BUSY)
increase_dmi_busy_delay(target);
else if (status == DMI_STATUS_SUCCESS)
break;
else
return ERROR_FAIL;
}
write_to_buf(buffer + next_read - address, value, MIN(size, 4));
log_memory_access(next_read, value, MIN(size, 4), true);
/* "Writes to sbcs while sbbusy is high result in undefined behavior.
* A debugger must not write to sbcs until it reads sbbusy as 0." */
if (read_sbcs_nonbusy(target, &sbcs_read) != ERROR_OK)