This is an automated email from Gerrit.
"Tomas Vanek <van...@fbl.cz>" just uploaded a new patch set to Gerrit, which
you can find at https://review.openocd.org/c/openocd/+/7372
-- gerrit
commit 1d334c2cd52ff068d86dd64b5e67687f858c4f8a
Author: Tomas Vanek <van...@fbl.cz>
Date: Tue Nov 22 12:29:52 2022 +0100
jtag/drivers/cmsis_dap: speed up long transfers using DAP_TransferBlock
DAP_TransferBlock command saves n - 3 bytes in comparison to DAP_Transfer,
where n is number of transfers.
Use DAP_TransferBlock optionaly to save some USB bandwidth.
The change increases the speed of the write transfer
from 40 KiB/s to 42 KiB/s @ USB FS, adapter speed 1000.
Signed-off-by: Tomas Vanek <van...@fbl.cz>
Change-Id: Ifde0159cfd44481d2b81b90daa088e731c03e26d
diff --git a/src/jtag/drivers/cmsis_dap.c b/src/jtag/drivers/cmsis_dap.c
index a7df8115e0..f5851b5e5b 100644
--- a/src/jtag/drivers/cmsis_dap.c
+++ b/src/jtag/drivers/cmsis_dap.c
@@ -768,10 +768,23 @@ static void cmsis_dap_swd_write_from_queue(struct
cmsis_dap *dap)
if (block->transfer_count == 0)
goto skip;
- command[0] = CMD_DAP_TFER;
+ /* DAP_TransferBlock increases the sum of command/response sizes
+ * (due to 16-bit Transfer Count) if used for less than 3 transfers */
+ bool block_cmd = cmsis_dap_handle->same_dap_cmd != DAP_CMD_DIFFER
+ && block->transfer_count > 3;
+ block->command = block_cmd ? CMD_DAP_TFER_BLOCK : CMD_DAP_TFER;
+
+ command[0] = block->command;
command[1] = 0x00; /* DAP Index */
- command[2] = block->transfer_count;
- size_t idx = 3;
+
+ unsigned int idx;
+ if (block_cmd) {
+ h_u16_to_le(&command[2], block->transfer_count);
+ idx = 4; /* The first transfer will store the common DAP
register */
+ } else {
+ command[2] = block->transfer_count;
+ idx = 3;
+ }
for (unsigned int i = 0; i < block->transfer_count; i++) {
struct pending_transfer_result *transfer =
&(block->transfers[i]);
@@ -802,7 +815,9 @@ static void cmsis_dap_swd_write_from_queue(struct cmsis_dap
*dap)
data &= ~CORUNDETECT;
}
- command[idx++] = (cmd >> 1) & 0x0f;
+ if (!block_cmd || i == 0)
+ command[idx++] = (cmd >> 1) & 0x0f;
+
if (!(cmd & SWD_CMD_RNW)) {
h_u32_to_le(&command[idx], data);
idx += 4;
@@ -847,20 +862,28 @@ static void cmsis_dap_swd_read_process(struct cmsis_dap
*dap, int timeout_ms)
}
uint8_t *resp = dap->response;
- if (resp[0] != CMD_DAP_TFER) {
+ if (resp[0] != block->command) {
LOG_ERROR("CMSIS-DAP command mismatch. Expected 0x%x received
0x%" PRIx8,
- CMD_DAP_TFER, resp[0]);
+ block->command, resp[0]);
queued_retval = ERROR_FAIL;
goto skip;
}
- unsigned int transfer_count = resp[1];
- uint8_t ack = resp[2] & 0x07;
- if (resp[2] & 0x08) {
+ unsigned int transfer_count;
+ unsigned int idx;
+ if (block->command == CMD_DAP_TFER_BLOCK) {
+ transfer_count = le_to_h_u16(&resp[1]);
+ idx = 3;
+ } else {
+ transfer_count = resp[1];
+ idx = 2;
+ }
+ if (resp[idx] & 0x08) {
LOG_DEBUG("CMSIS-DAP Protocol Error @ %d (wrong parity)",
transfer_count);
queued_retval = ERROR_FAIL;
goto skip;
}
+ uint8_t ack = resp[idx++] & 0x07;
if (ack != SWD_ACK_OK) {
LOG_DEBUG("SWD ack not OK @ %d %s", transfer_count,
ack == SWD_ACK_WAIT ? "WAIT" : ack == SWD_ACK_FAULT ?
"FAULT" : "JUNK");
@@ -875,7 +898,7 @@ static void cmsis_dap_swd_read_process(struct cmsis_dap
*dap, int timeout_ms)
LOG_DEBUG_IO("Received results of %d queued transactions FIFO index %u
timeout %i",
transfer_count, dap->pending_fifo_get_idx, timeout_ms);
- unsigned int idx = 3;
+
for (unsigned int i = 0; i < transfer_count; i++) {
struct pending_transfer_result *transfer =
&(block->transfers[i]);
if (transfer->cmd & SWD_CMD_RNW) {
@@ -924,19 +947,30 @@ static int cmsis_dap_swd_run_queue(void)
}
static unsigned int cmsis_dap_tfer_cmd_size(unsigned int write_count,
-
unsigned int read_count)
+ unsigned int
read_count, bool block_tfer)
{
- unsigned int size = 3; /* header */
- size += write_count * (1 + 4); /* DAP register + data */
- size += read_count; /* DAP register */
+ unsigned int size;
+ if (block_tfer) {
+ size = 5; /*
DAP_TransferBlock header */
+ size += write_count * 4; /* data */
+ } else {
+ size = 3; /*
DAP_Transfer header */
+ size += write_count * (1 + 4); /* DAP register + data */
+ size += read_count; /* DAP register
*/
+ }
return size;
}
static unsigned int cmsis_dap_tfer_resp_size(unsigned int write_count,
-
unsigned int read_count)
+ unsigned int
read_count, bool block_tfer)
{
- unsigned int size = 3; /* header */
- size += read_count * 4; /* data */
+ unsigned int size;
+ if (block_tfer)
+ size = 4; /*
DAP_TransferBlock response header */
+ else
+ size = 3; /*
DAP_Transfer response header */
+
+ size += read_count * 4; /* data */
return size;
}
@@ -948,13 +982,21 @@ static void cmsis_dap_swd_queue_cmd(uint8_t cmd, uint32_t
*dst, uint32_t data)
unsigned int write_count = cmsis_dap_handle->write_count;
unsigned int read_count = cmsis_dap_handle->read_count;
+ bool block_cmd;
+ if (write_count + read_count)
+ block_cmd = (cmd == cmsis_dap_handle->same_dap_cmd);
+ else
+ block_cmd = true;
+
if (cmd & SWD_CMD_RNW)
read_count++;
else
write_count++;
- unsigned int cmd_size = cmsis_dap_tfer_cmd_size(write_count,
read_count);
- unsigned int resp_size = cmsis_dap_tfer_resp_size(write_count,
read_count);
+ unsigned int cmd_size = cmsis_dap_tfer_cmd_size(write_count, read_count,
+
block_cmd);
+ unsigned int resp_size = cmsis_dap_tfer_resp_size(write_count,
read_count,
+
block_cmd);
/* Does the DAP Transfer command and the expected response fit into one
packet?
* Run the queue also before a targetsel - it cannot be queued */
@@ -985,6 +1027,11 @@ static void cmsis_dap_swd_queue_cmd(uint8_t cmd, uint32_t
*dst, uint32_t data)
struct pending_transfer_result *transfer =
&(block->transfers[block->transfer_count]);
transfer->data = data;
transfer->cmd = cmd;
+ if (block->transfer_count == 0)
+ cmsis_dap_handle->same_dap_cmd = cmd;
+ else if (cmd != cmsis_dap_handle->same_dap_cmd)
+ cmsis_dap_handle->same_dap_cmd = DAP_CMD_DIFFER;
+
if (cmd & SWD_CMD_RNW) {
/* Queue a read transaction */
transfer->buffer = dst;
diff --git a/src/jtag/drivers/cmsis_dap.h b/src/jtag/drivers/cmsis_dap.h
index af437de2f9..48c6e5a7a5 100644
--- a/src/jtag/drivers/cmsis_dap.h
+++ b/src/jtag/drivers/cmsis_dap.h
@@ -21,6 +21,7 @@ struct pending_transfer_result {
struct pending_request_block {
struct pending_transfer_result *transfers;
unsigned int transfer_count;
+ uint8_t command;
};
struct cmsis_dap {
@@ -37,6 +38,8 @@ struct cmsis_dap {
* that would result from the queue run */
unsigned int write_count;
unsigned int read_count;
+ uint8_t same_dap_cmd;
+#define DAP_CMD_DIFFER UINT8_MAX
struct pending_request_block pending_fifo[MAX_PENDING_REQUESTS];
unsigned int packet_count;
--
