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PTI feature to allow user to name and mark masterchannel request.
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This feature addition provides a new parameter in
pti_request_masterchannel() to allow the user
to provide their own name to mark the request when
the trace is viewed in a PTI SW trace viewer
(like MPTA).  If a name is not provided and
NULL is provided, the 'current' process name is used.
API function header documentation documents this.

Signed-off-by: Jeremy Rocher <rocher.jeremy@gmail.com>
Signed-off-by: J Freyensee <james_p_freyensee@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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J Freyensee authored and Greg Kroah-Hartman committed Jul 1, 2011
1 parent fc360ee commit 8168e9c
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Showing 2 changed files with 62 additions and 40 deletions.
99 changes: 60 additions & 39 deletions drivers/misc/pti.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -146,45 +146,54 @@ static void pti_write_to_aperture(struct pti_masterchannel *mc,
/**
* pti_control_frame_built_and_sent()- control frame build and send function.
*
* @mc: The master / channel structure on which the function
* built a control frame.
* @mc: The master / channel structure on which the function
* built a control frame.
* @thread_name: The thread name associated with the master / channel or
* 'NULL' if using the 'current' global variable.
*
* To be able to post process the PTI contents on host side, a control frame
* is added before sending any PTI content. So the host side knows on
* each PTI frame the name of the thread using a dedicated master / channel.
* The thread name is retrieved from the 'current' global variable.
* The thread name is retrieved from 'current' global variable if 'thread_name'
* is 'NULL', else it is retrieved from 'thread_name' parameter.
* This function builds this frame and sends it to a master ID CONTROL_ID.
* The overhead is only 32 bytes since the driver only writes to HW
* in 32 byte chunks.
*/

static void pti_control_frame_built_and_sent(struct pti_masterchannel *mc)
static void pti_control_frame_built_and_sent(struct pti_masterchannel *mc,
const char *thread_name)
{
struct pti_masterchannel mccontrol = {.master = CONTROL_ID,
.channel = 0};
const char *thread_name_p;
const char *control_format = "%3d %3d %s";
u8 control_frame[CONTROL_FRAME_LEN];

/*
* Since we access the comm member in current's task_struct,
* we only need to be as large as what 'comm' in that
* structure is.
*/
char comm[TASK_COMM_LEN];
if (!thread_name) {
/*
* Since we access the comm member in current's task_struct,
* we only need to be as large as what 'comm' in that
* structure is.
*/
char comm[TASK_COMM_LEN];

if (!in_interrupt())
get_task_comm(comm, current);
else
strncpy(comm, "Interrupt", TASK_COMM_LEN);
if (!in_interrupt())
get_task_comm(comm, current);
else
strncpy(comm, "Interrupt", TASK_COMM_LEN);

/* Absolutely ensure our buffer is zero terminated. */
comm[TASK_COMM_LEN-1] = 0;
/* Absolutely ensure our buffer is zero terminated. */
comm[TASK_COMM_LEN-1] = 0;
thread_name_p = comm;
} else {
thread_name_p = thread_name;
}

mccontrol.channel = pti_control_channel;
pti_control_channel = (pti_control_channel + 1) & 0x7f;

snprintf(control_frame, CONTROL_FRAME_LEN, control_format, mc->master,
mc->channel, comm);
mc->channel, thread_name_p);
pti_write_to_aperture(&mccontrol, control_frame, strlen(control_frame));
}

Expand All @@ -206,18 +215,20 @@ static void pti_write_full_frame_to_aperture(struct pti_masterchannel *mc,
const unsigned char *buf,
int len)
{
pti_control_frame_built_and_sent(mc);
pti_control_frame_built_and_sent(mc, NULL);
pti_write_to_aperture(mc, (u8 *)buf, len);
}

/**
* get_id()- Allocate a master and channel ID.
*
* @id_array: an array of bits representing what channel
* id's are allocated for writing.
* @max_ids: The max amount of available write IDs to use.
* @base_id: The starting SW channel ID, based on the Intel
* PTI arch.
* @id_array: an array of bits representing what channel
* id's are allocated for writing.
* @max_ids: The max amount of available write IDs to use.
* @base_id: The starting SW channel ID, based on the Intel
* PTI arch.
* @thread_name: The thread name associated with the master / channel or
* 'NULL' if using the 'current' global variable.
*
* Returns:
* pti_masterchannel struct with master, channel ID address
Expand All @@ -227,7 +238,10 @@ static void pti_write_full_frame_to_aperture(struct pti_masterchannel *mc,
* channel id. The bit is one if the id is taken and 0 if free. For
* every master there are 128 channel id's.
*/
static struct pti_masterchannel *get_id(u8 *id_array, int max_ids, int base_id)
static struct pti_masterchannel *get_id(u8 *id_array,
int max_ids,
int base_id,
const char *thread_name)
{
struct pti_masterchannel *mc;
int i, j, mask;
Expand Down Expand Up @@ -257,7 +271,7 @@ static struct pti_masterchannel *get_id(u8 *id_array, int max_ids, int base_id)
mc->master = base_id;
mc->channel = ((i & 0xf)<<3) + j;
/* write new master Id / channel Id allocation to channel control */
pti_control_frame_built_and_sent(mc);
pti_control_frame_built_and_sent(mc, thread_name);
return mc;
}

Expand All @@ -273,18 +287,22 @@ static struct pti_masterchannel *get_id(u8 *id_array, int max_ids, int base_id)
* a master, channel ID address
* to write to PTI HW.
*
* @type: 0- request Application master, channel aperture ID write address.
* 1- request OS master, channel aperture ID write
* address.
* 2- request Modem master, channel aperture ID
* write address.
* Other values, error.
* @type: 0- request Application master, channel aperture ID
* write address.
* 1- request OS master, channel aperture ID write
* address.
* 2- request Modem master, channel aperture ID
* write address.
* Other values, error.
* @thread_name: The thread name associated with the master / channel or
* 'NULL' if using the 'current' global variable.
*
* Returns:
* pti_masterchannel struct
* 0 for error
*/
struct pti_masterchannel *pti_request_masterchannel(u8 type)
struct pti_masterchannel *pti_request_masterchannel(u8 type,
const char *thread_name)
{
struct pti_masterchannel *mc;

Expand All @@ -293,15 +311,18 @@ struct pti_masterchannel *pti_request_masterchannel(u8 type)
switch (type) {

case 0:
mc = get_id(drv_data->ia_app, MAX_APP_IDS, APP_BASE_ID);
mc = get_id(drv_data->ia_app, MAX_APP_IDS,
APP_BASE_ID, thread_name);
break;

case 1:
mc = get_id(drv_data->ia_os, MAX_OS_IDS, OS_BASE_ID);
mc = get_id(drv_data->ia_os, MAX_OS_IDS,
OS_BASE_ID, thread_name);
break;

case 2:
mc = get_id(drv_data->ia_modem, MAX_MODEM_IDS, MODEM_BASE_ID);
mc = get_id(drv_data->ia_modem, MAX_MODEM_IDS,
MODEM_BASE_ID, thread_name);
break;
default:
mc = NULL;
Expand Down Expand Up @@ -471,9 +492,9 @@ static int pti_tty_install(struct tty_driver *driver, struct tty_struct *tty)
return -ENOMEM;

if (idx == PTITTY_MINOR_START)
pti_tty_data->mc = pti_request_masterchannel(0);
pti_tty_data->mc = pti_request_masterchannel(0, NULL);
else
pti_tty_data->mc = pti_request_masterchannel(2);
pti_tty_data->mc = pti_request_masterchannel(2, NULL);

if (pti_tty_data->mc == NULL)
return -ENXIO;
Expand Down Expand Up @@ -560,7 +581,7 @@ static int pti_char_open(struct inode *inode, struct file *filp)
* before assigning the value to filp->private_data.
* Slightly easier to debug if this driver needs debugging.
*/
mc = pti_request_masterchannel(0);
mc = pti_request_masterchannel(0, NULL);
if (mc == NULL)
return -ENOMEM;
filp->private_data = mc;
Expand Down
3 changes: 2 additions & 1 deletion include/linux/pti.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -36,7 +36,8 @@ struct pti_masterchannel {

/* the following functions are defined in misc/pti.c */
void pti_writedata(struct pti_masterchannel *mc, u8 *buf, int count);
struct pti_masterchannel *pti_request_masterchannel(u8 type);
struct pti_masterchannel *pti_request_masterchannel(u8 type,
const char *thread_name);
void pti_release_masterchannel(struct pti_masterchannel *mc);

#endif /*PTI_H_*/

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