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wr-switch-sw
Commit 5238b9d4 authored by Alessandro Rubini's avatar Alessandro Rubini Committed by Adam Wujek
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kernel/wr_pstats: support "zeroing" of counters. 

By writing anything to a port file, you zero the counters for that
port. By writing to "info" or "description" you zero counters for
all ports.

Zeroing is performed by copying the current values to a new array,
and always subytracting that array to the current counter values.

No zeroing is performed for network statistics, that still reads
the "real" counters, featuring an overflow at 4G but no zeroing ever.

To simplify a little the code, I turned the one-dimensional array
with index arithmetics into a two-dimensional array, so the compiler
makes the math for us, transparently.

NOTE: the spinlock must be audited, we are not safe yet, not only
because of this patch.
Signed-off-by: Alessandro Rubini's avatarAlessandro Rubini <rubini@gnudd.com>
parent 7067fecc
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Showing with 51 additions and 24 deletions
kernel/wr_pstats/wr_pstats.c
View file @ 5238b9d4
......@@ -44,7 +44,9 @@ const char *portnames[] = {"port0", "port1", "port2", "port3", "port4",
struct cntrs_dev {
unsigned int cntrs[PSTATS_NPORTS*PSTATS_CNT_PP];
unsigned int cntrs[PSTATS_NPORTS][PSTATS_CNT_PP];
unsigned int zeros[PSTATS_NPORTS][PSTATS_CNT_PP];
unsigned int userv[PSTATS_NPORTS][PSTATS_CNT_PP];
struct PSTATS_WB __iomem *regs;
/* prevents from simultaneous access to cntrs array from tasklet and
......@@ -63,11 +65,6 @@ static struct cntrs_dev pstats_dev; /*static data cleared at build time*/
/* pstats info for sysfs */
static int pstats_info[PINFO_SIZE];
static unsigned int *cntr_idx(unsigned int *tab, int port, int idx)
{
return &tab[port*PSTATS_CNT_PP+idx];
}
/* function converting Layer1 and Layer2 words read from HW to counter value */
static unsigned int hwcnt_to_sw(uint32_t l1_val, uint32_t l2_val, int n)
{
......@@ -165,7 +162,7 @@ static void pstats_tlet_fn(unsigned long arg)
for (cntr = 0; cntr < PSTATS_CNT_PP; ++cntr) {
/*decode counters overflow flags to increment coutners*/
if ((*cntrs_ov)>>cntr & 0x01) {
ptr = cntr_idx(device->cntrs, port, cntr);
ptr = &(device->cntrs[port][cntr]);
*ptr += 1<<PSTATS_MSB_SHIFT;
}
}
......@@ -217,7 +214,7 @@ static int rd_cnt_word(int port, int adr)
if (4*adr+i >= PSTATS_CNT_PP)
break;
spin_lock(&pstats_dev.port_mutex[port]);
ptr = cntr_idx(pstats_dev.cntrs, port, 4*adr+i);
ptr = &(pstats_dev.cntrs[port][4 * adr + i]);
*ptr &= PSTATS_MSB_MSK;
*ptr |= hwcnt_to_sw(val[0], val[1], i);
spin_unlock(&pstats_dev.port_mutex[port]);
......@@ -236,15 +233,29 @@ static int pstats_rd_cntrs(int port)
return 0;
}
static void pstats_zero(int port)
{
pstats_rd_cntrs(port);
spin_lock(&pstats_dev.port_mutex[port]);
memcpy(pstats_dev.zeros[port],
pstats_dev.cntrs[port],
sizeof(pstats_dev.zeros[port]));
spin_unlock(&pstats_dev.port_mutex[port]);
}
/* SYSCTL handler, pass description of counters */
static int pstats_desc_handler(ctl_table *ctl, int write, void *buffer,
size_t *lenp, loff_t *ppos)
{
unsigned int data;
unsigned int version;
int port;
if (write) /* write not supported */
return 0;
if (write) { /* write description: zero all ports */
for (port = 0; port < pstats_nports; port++)
pstats_zero(port);
return *lenp;
}
/* get version number */
data = pstats_readl(pstats_dev, INFO);
......@@ -258,20 +269,33 @@ static int pstats_desc_handler(ctl_table *ctl, int write, void *buffer,
return proc_dostring(ctl, 0, buffer, lenp, ppos);
}
/* SYSCTL handler, reads counters from hw and passes to sysfs */
static int pstats_handler(ctl_table *ctl, int write, void *buffer,
size_t *lenp, loff_t *ppos)
{
int port;
uint32_t int data;
if (write) /* write not supported */
return 0;
int i, port;
uint32_t data;
struct cntrs_dev *d = &pstats_dev;
port = (int)ctl->extra1;
if (write) {
/* on write, we zero the counters */
if (port < pstats_nports) {
pstats_zero(port);
} else { /* write to info: zero them all */
for (port = 0; port < pstats_nports; port++)
pstats_zero(port);
}
return *lenp;
}
if (port < pstats_nports) {
pstats_rd_cntrs(port);
} else {
for (i = 0; i < PSTATS_CNT_PP; i++)
d->userv[port][i] = d->cntrs[port][i] - d->zeros[port][i];
} else {
/* read stuff for info file */
data = pstats_readl(pstats_dev, INFO);
pstats_info[PINFO_VER] = PSTATS_INFO_VER_R(data);
......@@ -279,10 +303,11 @@ static int pstats_handler(ctl_table *ctl, int write, void *buffer,
pstats_info[PINFO_CNTPP] = PSTATS_INFO_CPP_R(data);
}
return_dointvec(ctl, 0, buffer, lenp, ppos);
return proc_dointvec(ctl, 0, buffer, lenp, ppos);
}
static ctl_table pstats_ctl_table[21]; /* initialized in _init function */
/* one per port, then info and description, and terminator, filled at init time */
static ctl_table pstats_ctl_table[PSTATS_NPORTS + 3];
static ctl_table proc_table[] = {
{
......@@ -302,8 +327,10 @@ int pstats_callback(int epnum, unsigned int cntr[PSTATS_CNT_PP])
int i;
pstats_rd_cntrs(epnum);
/* We could just memcpy, but this has to change anyways*/
for (i = 0; i < PSTATS_CNT_PP; i++)
cntr[i] = *cntr_idx(pstats_dev.cntrs, epnum, i);
cntr[i] = pstats_dev.cntrs[epnum][i];
return 0;
}
......@@ -323,17 +350,17 @@ static int __init pstats_init(void)
for (i = 0; i < pstats_nports; ++i) {
pstats_ctl_table[i].procname = portnames[i];
pstats_ctl_table[i].data = &pstats_dev.cntrs[i*PSTATS_CNT_PP];
pstats_ctl_table[i].data = &pstats_dev.userv[i];
pstats_ctl_table[i].maxlen = PSTATS_CNT_PP*sizeof(unsigned int);
pstats_ctl_table[i].mode = 0444;
pstats_ctl_table[i].mode = 0644;
pstats_ctl_table[i].proc_handler = pstats_handler;
pstats_ctl_table[i].extra1 = (void *)i;
}
/* the last one with info about pstats */
/* the last-but-one with info about pstats */
pstats_ctl_table[i].procname = "info";
pstats_ctl_table[i].data = pstats_info;
pstats_ctl_table[i].maxlen = PINFO_SIZE * sizeof(int);
pstats_ctl_table[i].mode = 0444;
pstats_ctl_table[i].mode = 0644;
pstats_ctl_table[i].proc_handler = pstats_handler;
pstats_ctl_table[i].extra1 = (void *)i;
......@@ -343,7 +370,7 @@ static int __init pstats_init(void)
pstats_ctl_table[i].procname = "description";
pstats_ctl_table[i].data = NULL;
pstats_ctl_table[i].maxlen = 0;
pstats_ctl_table[i].mode = 0444;
pstats_ctl_table[i].mode = 0644;
pstats_ctl_table[i].proc_handler = pstats_desc_handler;
pstats_ctl_table[i].extra1 = (void *)i;
......
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