/*
* msm_rpm_log_copy() - Copies messages from a volatile circular buffer in
* the RPM's shared memory into a private local buffer
* msg_buffer: pointer to local buffer (string)
* buf_len: length of local buffer in bytes
* read_start_idx: index into shared memory buffer
*
* Return value: number of bytes written to the local buffer
*
* Copies messages stored in a circular buffer in the RPM Message Memory into
* a specified local buffer. The RPM processor is unaware of these reading
* efforts, so care is taken to make sure that messages are valid both before
* and after reading. The RPM processor utilizes a ULog driver to write the
* log. The RPM processor maintains tail and head indices. These correspond
* to the next byte to write into, and the first valid byte, respectively.
* Both indices increase monotonically (except for rollover).
*
* Messages take the form of [(u32)length] [(char)data0,1,...] in which the
* length specifies the number of payload bytes. Messages must be 4 byte
* aligned, so padding is added at the end of a message as needed.
*
* Print format:
* - 0xXX, 0xXX, 0xXX
* - 0xXX
* etc...
*/
static u32 msm_rpm_log_copy(const struct msm_rpm_log_platform_data *pdata,
char *msg_buffer, u32 buf_len, u32 *read_idx)
{
u32 head_idx, tail_idx;
u32 pos = 0;
u32 i = 0;
u32 msg_len;
u32 pos_start;
char temp[4];
tail_idx = msm_rpm_log_read(pdata, MSM_RPM_LOG_PAGE_INDICES,
MSM_RPM_LOG_TAIL);
head_idx = msm_rpm_log_read(pdata, MSM_RPM_LOG_PAGE_INDICES,
MSM_RPM_LOG_HEAD);
/* loop while the remote buffer has valid messages left to read */
while (tail_idx - head_idx > 0 && tail_idx - *read_idx > 0) {
head_idx = msm_rpm_log_read(pdata, MSM_RPM_LOG_PAGE_INDICES,
MSM_RPM_LOG_HEAD);
tail_idx = msm_rpm_log_read(pdata, MSM_RPM_LOG_PAGE_INDICES,
MSM_RPM_LOG_TAIL);
/* check if the message to be read is valid */
if (tail_idx - *read_idx > tail_idx - head_idx) {
*read_idx = head_idx;
continue;
}
/*
* Ensure that all indices are 4 byte aligned.
* This conditions is required to interact with a ULog buffer
* properly.
*/
if (!IS_ALIGNED((tail_idx | head_idx | *read_idx), 4))
break;
msg_len = msm_rpm_log_read(pdata, MSM_RPM_LOG_PAGE_BUFFER,
((*read_idx) & pdata->log_len_mask) >> 2);
/* Message length for 8974 is first 2 bytes.
* Exclude message length and format from message length.
*/
if (pdata->version == VERSION_8974) {
msg_len = (msg_len & RPM_ULOG_LENGTH_MASK) >>
RPM_ULOG_LENGTH_SHIFT;
msg_len -= 4;
}
/* handle messages that claim to be longer than the log */
if (PADDED_LENGTH(msg_len) > tail_idx - *read_idx - 4)
msg_len = tail_idx - *read_idx - 4;
/* check that the local buffer has enough space for this msg */
if (pos + PRINTED_LENGTH(msg_len) > buf_len)
break;
pos_start = pos;
pos += scnprintf(msg_buffer + pos, buf_len - pos, "- ");
/* copy message payload to local buffer */
for (i = 0; i < msg_len; i++) {
/* read from shared memory 4 bytes at a time */
if (IS_ALIGNED(i, 4))
*((u32 *)temp) = msm_rpm_log_read(pdata,
MSM_RPM_LOG_PAGE_BUFFER,
((*read_idx + 4 + i) &
pdata->log_len_mask) >> 2);
pos += scnprintf(msg_buffer + pos, buf_len - pos,
"0x%02X, ", temp[i & 0x03]);
}
pos += scnprintf(msg_buffer + pos, buf_len - pos, "\n");
head_idx = msm_rpm_log_read(pdata, MSM_RPM_LOG_PAGE_INDICES,
MSM_RPM_LOG_HEAD);
tail_idx = msm_rpm_log_read(pdata, MSM_RPM_LOG_PAGE_INDICES,
MSM_RPM_LOG_TAIL);
/* roll back if message that was read is not still valid */
if (tail_idx - *read_idx > tail_idx - head_idx)
pos = pos_start;
*read_idx += PADDED_LENGTH(msg_len) + 4;
}
static u32 msm_rpm_log_copy(const struct msm_rpm_log_platform_data *pdata,
char *msg_buffer, u32 buf_len, u32 *read_idx)
{
u32 head_idx, tail_idx;
u32 pos = 0;
u32 i = 0;
u32 msg_len;
u32 pos_start;
char temp[4];
tail_idx = msm_rpm_log_read(pdata, MSM_RPM_LOG_PAGE_INDICES,
MSM_RPM_LOG_TAIL);
head_idx = msm_rpm_log_read(pdata, MSM_RPM_LOG_PAGE_INDICES,
MSM_RPM_LOG_HEAD);
while (tail_idx - head_idx > 0 && tail_idx - *read_idx > 0) {
head_idx = msm_rpm_log_read(pdata, MSM_RPM_LOG_PAGE_INDICES,
MSM_RPM_LOG_HEAD);
if (tail_idx - *read_idx > tail_idx - head_idx) {
*read_idx = head_idx;
continue;
}
if (tail_idx - head_idx > pdata->log_len ||
!IS_ALIGNED((tail_idx | head_idx | *read_idx), 4))
break;
msg_len = msm_rpm_log_read(pdata, MSM_RPM_LOG_PAGE_BUFFER,
(*read_idx >> 2) & pdata->log_len_mask);
if (PADDED_LENGTH(msg_len) > tail_idx - *read_idx - 4)
msg_len = tail_idx - *read_idx - 4;
if (pos + PRINTED_LENGTH(msg_len) > buf_len)
break;
pos_start = pos;
pos += scnprintf(msg_buffer + pos, buf_len - pos, "- ");
for (i = 0; i < msg_len; i++) {
if (IS_ALIGNED(i, 4))
*((u32 *)temp) = msm_rpm_log_read(pdata,
MSM_RPM_LOG_PAGE_BUFFER,
((*read_idx + 4 + i) >> 2) &
pdata->log_len_mask);
pos += scnprintf(msg_buffer + pos, buf_len - pos,
"0x%02X, ", temp[i & 0x03]);
}
pos += scnprintf(msg_buffer + pos, buf_len - pos, "\n");
head_idx = msm_rpm_log_read(pdata, MSM_RPM_LOG_PAGE_INDICES,
MSM_RPM_LOG_HEAD);
if (tail_idx - *read_idx > tail_idx - head_idx)
pos = pos_start;
*read_idx += PADDED_LENGTH(msg_len) + 4;
}
return pos;
}