* counter set via normal file operations.
*/
-static atomic_t cfset_opencnt = ATOMIC_INIT(0); /* Excl. access */
+static atomic_t cfset_opencnt = ATOMIC_INIT(0); /* Access count */
static DEFINE_MUTEX(cfset_ctrset_mutex);/* Synchronize access to hardware */
struct cfset_call_on_cpu_parm { /* Parm struct for smp_call_on_cpu */
unsigned int sets; /* Counter set bit mask */
atomic_t cpus_ack; /* # CPUs successfully executed func */
};
-static struct cfset_request { /* CPUs and counter set bit mask */
+static struct cfset_session { /* CPUs and counter set bit mask */
+ struct list_head head; /* Head of list of active processes */
+} cfset_session = {
+ .head = LIST_HEAD_INIT(cfset_session.head)
+};
+
+struct cfset_request { /* CPUs and counter set bit mask */
unsigned long ctrset; /* Bit mask of counter set to read */
cpumask_t mask; /* CPU mask to read from */
-} cfset_request;
+ struct list_head node; /* Chain to cfset_session.head */
+};
+
+static void cfset_session_init(void)
+{
+ INIT_LIST_HEAD(&cfset_session.head);
+}
+
+/* Remove current request from global bookkeeping. Maintain a counter set bit
+ * mask on a per CPU basis.
+ * Done in process context under mutex protection.
+ */
+static void cfset_session_del(struct cfset_request *p)
+{
+ list_del(&p->node);
+}
-static void cfset_ctrset_clear(void)
+/* Add current request to global bookkeeping. Maintain a counter set bit mask
+ * on a per CPU basis.
+ * Done in process context under mutex protection.
+ */
+static void cfset_session_add(struct cfset_request *p)
{
- cpumask_clear(&cfset_request.mask);
- cfset_request.ctrset = 0;
+ list_add(&p->node, &cfset_session.head);
}
/* The /dev/hwctr device access uses PMU_F_IN_USE to mark the device access
struct cfset_call_on_cpu_parm *p = parm;
int rc;
- cpuhw->dev_state = 0;
+ /* Check if any counter set used by /dev/hwc */
for (rc = CPUMF_CTR_SET_BASIC; rc < CPUMF_CTR_SET_MAX; ++rc)
- if ((p->sets & cpumf_ctr_ctl[rc]))
- atomic_dec(&cpuhw->ctr_set[rc]);
- rc = lcctl(cpuhw->state); /* Keep perf_event_open counter sets */
+ if ((p->sets & cpumf_ctr_ctl[rc])) {
+ if (!atomic_dec_return(&cpuhw->ctr_set[rc])) {
+ ctr_set_disable(&cpuhw->dev_state,
+ cpumf_ctr_ctl[rc]);
+ ctr_set_stop(&cpuhw->dev_state,
+ cpumf_ctr_ctl[rc]);
+ }
+ }
+ /* Keep perf_event_open counter sets */
+ rc = lcctl(cpuhw->dev_state | cpuhw->state);
if (rc)
pr_err("Counter set stop %#llx of /dev/%s failed rc=%i\n",
cpuhw->state, S390_HWCTR_DEVICE, rc);
- cpuhw->flags &= ~PMU_F_IN_USE;
+ if (!cpuhw->dev_state)
+ cpuhw->flags &= ~PMU_F_IN_USE;
debug_sprintf_event(cf_dbg, 4, "%s rc %d state %#llx dev_state %#llx\n",
__func__, rc, cpuhw->state, cpuhw->dev_state);
}
debug_sprintf_event(cf_dbg, 4, "%s state %#llx dev_state %#llx\n",
__func__, cpuhw->state, cpuhw->dev_state);
+ cpuhw->dev_state = 0;
rc = lcctl(cpuhw->state); /* Keep perf_event_open counter sets */
if (rc)
pr_err("Counter set release %#llx of /dev/%s failed rc=%i\n",
cpuhw->state, S390_HWCTR_DEVICE, rc);
- cpuhw->dev_state = 0;
+}
+
+/* This modifies the process CPU mask to adopt it to the currently online
+ * CPUs. Offline CPUs can not be addresses. This call terminates the access
+ * and is usually followed by close() or a new iotcl(..., START, ...) which
+ * creates a new request structure.
+ */
+static void cfset_all_stop(struct cfset_request *req)
+{
+ struct cfset_call_on_cpu_parm p = {
+ .sets = req->ctrset,
+ };
+
+ cpumask_and(&req->mask, &req->mask, cpu_online_mask);
+ on_each_cpu_mask(&req->mask, cfset_ioctl_off, &p, 1);
}
/* Release function is also called when application gets terminated without
*/
static int cfset_release(struct inode *inode, struct file *file)
{
- on_each_cpu(cfset_release_cpu, NULL, 1);
+ mutex_lock(&cfset_ctrset_mutex);
+ /* Open followed by close/exit has no private_data */
+ if (file->private_data) {
+ cfset_all_stop(file->private_data);
+ cfset_session_del(file->private_data);
+ kfree(file->private_data);
+ file->private_data = NULL;
+ }
+ if (!atomic_dec_return(&cfset_opencnt))
+ on_each_cpu(cfset_release_cpu, NULL, 1);
+ mutex_unlock(&cfset_ctrset_mutex);
+
hw_perf_event_destroy(NULL);
- cfset_ctrset_clear();
- atomic_set(&cfset_opencnt, 0);
return 0;
}
{
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
- /* Only one user space program can open /dev/hwctr */
- if (atomic_xchg(&cfset_opencnt, 1))
- return -EBUSY;
+ mutex_lock(&cfset_ctrset_mutex);
+ if (atomic_inc_return(&cfset_opencnt) == 1)
+ cfset_session_init();
+ mutex_unlock(&cfset_ctrset_mutex);
cpumf_hw_inuse();
file->private_data = NULL;
return nonseekable_open(inode, file);
}
-static int cfset_all_stop(void)
+static int cfset_all_start(struct cfset_request *req)
{
struct cfset_call_on_cpu_parm p = {
- .sets = cfset_request.ctrset,
- };
- cpumask_var_t mask;
-
- if (!alloc_cpumask_var(&mask, GFP_KERNEL))
- return -ENOMEM;
- cpumask_and(mask, &cfset_request.mask, cpu_online_mask);
- on_each_cpu_mask(mask, cfset_ioctl_off, &p, 1);
- free_cpumask_var(mask);
- return 0;
-}
-
-static int cfset_all_start(void)
-{
- struct cfset_call_on_cpu_parm p = {
- .sets = cfset_request.ctrset,
+ .sets = req->ctrset,
.cpus_ack = ATOMIC_INIT(0),
};
cpumask_var_t mask;
if (!alloc_cpumask_var(&mask, GFP_KERNEL))
return -ENOMEM;
- cpumask_and(mask, &cfset_request.mask, cpu_online_mask);
+ cpumask_and(mask, &req->mask, cpu_online_mask);
on_each_cpu_mask(mask, cfset_ioctl_on, &p, 1);
if (atomic_read(&p.cpus_ack) != cpumask_weight(mask)) {
on_each_cpu_mask(mask, cfset_ioctl_off, &p, 1);
cpuhw->sets, cpuhw->used);
}
-static int cfset_all_read(unsigned long arg)
+static int cfset_all_read(unsigned long arg, struct cfset_request *req)
{
struct cfset_call_on_cpu_parm p;
cpumask_var_t mask;
if (!alloc_cpumask_var(&mask, GFP_KERNEL))
return -ENOMEM;
- p.sets = cfset_request.ctrset;
- cpumask_and(mask, &cfset_request.mask, cpu_online_mask);
+ p.sets = req->ctrset;
+ cpumask_and(mask, &req->mask, cpu_online_mask);
on_each_cpu_mask(mask, cfset_cpu_read, &p, 1);
rc = cfset_all_copy(arg, mask);
free_cpumask_var(mask);
return rc;
}
-static long cfset_ioctl_read(unsigned long arg)
+static long cfset_ioctl_read(unsigned long arg, struct cfset_request *req)
{
struct s390_ctrset_read read;
- int ret = 0;
+ int ret = -ENODATA;
- if (copy_from_user(&read, (char __user *)arg, sizeof(read)))
- return -EFAULT;
- ret = cfset_all_read(arg);
+ if (req && req->ctrset) {
+ if (copy_from_user(&read, (char __user *)arg, sizeof(read)))
+ return -EFAULT;
+ ret = cfset_all_read(arg, req);
+ }
return ret;
}
-static long cfset_ioctl_stop(void)
+static long cfset_ioctl_stop(struct file *file)
{
- int ret = ENXIO;
-
- if (cfset_request.ctrset) {
- ret = cfset_all_stop();
- cfset_ctrset_clear();
+ struct cfset_request *req = file->private_data;
+ int ret = -ENXIO;
+
+ if (req) {
+ cfset_all_stop(req);
+ cfset_session_del(req);
+ kfree(req);
+ file->private_data = NULL;
+ ret = 0;
}
return ret;
}
-static long cfset_ioctl_start(unsigned long arg)
+static long cfset_ioctl_start(unsigned long arg, struct file *file)
{
struct s390_ctrset_start __user *ustart;
struct s390_ctrset_start start;
+ struct cfset_request *preq;
void __user *umask;
unsigned int len;
int ret = 0;
size_t need;
- if (cfset_request.ctrset)
+ if (file->private_data)
return -EBUSY;
ustart = (struct s390_ctrset_start __user *)arg;
if (copy_from_user(&start, ustart, sizeof(start)))
return -EINVAL; /* Invalid counter set */
if (!start.counter_sets)
return -EINVAL; /* No counter set at all? */
- cpumask_clear(&cfset_request.mask);
+
+ preq = kzalloc(sizeof(*preq), GFP_KERNEL);
+ if (!preq)
+ return -ENOMEM;
+ cpumask_clear(&preq->mask);
len = min_t(u64, start.cpumask_len, cpumask_size());
umask = (void __user *)start.cpumask;
- if (copy_from_user(&cfset_request.mask, umask, len))
+ if (copy_from_user(&preq->mask, umask, len)) {
+ kfree(preq);
return -EFAULT;
- if (cpumask_empty(&cfset_request.mask))
+ }
+ if (cpumask_empty(&preq->mask)) {
+ kfree(preq);
return -EINVAL;
+ }
need = cfset_needspace(start.counter_sets);
- if (put_user(need, &ustart->data_bytes))
- ret = -EFAULT;
- if (ret)
- goto out;
- cfset_request.ctrset = start.counter_sets;
- ret = cfset_all_start();
-out:
- if (ret)
- cfset_ctrset_clear();
- debug_sprintf_event(cf_dbg, 4, "%s sets %#lx need %ld ret %d\n",
- __func__, cfset_request.ctrset, need, ret);
+ if (put_user(need, &ustart->data_bytes)) {
+ kfree(preq);
+ return -EFAULT;
+ }
+ preq->ctrset = start.counter_sets;
+ ret = cfset_all_start(preq);
+ if (!ret) {
+ cfset_session_add(preq);
+ file->private_data = preq;
+ debug_sprintf_event(cf_dbg, 4, "%s set %#lx need %ld ret %d\n",
+ __func__, preq->ctrset, need, ret);
+ } else {
+ kfree(preq);
+ }
return ret;
}
* counter set keeps running until explicitly stopped. Returns the number
* of bytes needed to store the counter values. If another S390_HWCTR_START
* ioctl subcommand is called without a previous S390_HWCTR_STOP stop
- * command, -EBUSY is returned.
+ * command on the same file descriptor, -EBUSY is returned.
* S390_HWCTR_READ: Read the counter set values from specified CPU list given
* with the S390_HWCTR_START command.
* S390_HWCTR_STOP: Stops the counter sets on the CPU list given with the
mutex_lock(&cfset_ctrset_mutex);
switch (cmd) {
case S390_HWCTR_START:
- ret = cfset_ioctl_start(arg);
+ ret = cfset_ioctl_start(arg, file);
break;
case S390_HWCTR_STOP:
- ret = cfset_ioctl_stop();
+ ret = cfset_ioctl_stop(file);
break;
case S390_HWCTR_READ:
- ret = cfset_ioctl_read(arg);
+ ret = cfset_ioctl_read(arg, file->private_data);
break;
default:
ret = -ENOTTY;
.fops = &cfset_fops,
};
+/* Hotplug add of a CPU. Scan through all active processes and add
+ * that CPU to the list of CPUs supplied with ioctl(..., START, ...).
+ */
int cfset_online_cpu(unsigned int cpu)
{
struct cfset_call_on_cpu_parm p;
+ struct cfset_request *rp;
mutex_lock(&cfset_ctrset_mutex);
- if (cfset_request.ctrset) {
- p.sets = cfset_request.ctrset;
- cfset_ioctl_on(&p);
- cpumask_set_cpu(cpu, &cfset_request.mask);
+ if (!list_empty(&cfset_session.head)) {
+ list_for_each_entry(rp, &cfset_session.head, node) {
+ p.sets = rp->ctrset;
+ cfset_ioctl_on(&p);
+ cpumask_set_cpu(cpu, &rp->mask);
+ }
}
mutex_unlock(&cfset_ctrset_mutex);
return 0;
}
+/* Hotplug remove of a CPU. Scan through all active processes and clear
+ * that CPU from the list of CPUs supplied with ioctl(..., START, ...).
+ */
int cfset_offline_cpu(unsigned int cpu)
{
struct cfset_call_on_cpu_parm p;
+ struct cfset_request *rp;
mutex_lock(&cfset_ctrset_mutex);
- if (cfset_request.ctrset) {
- p.sets = cfset_request.ctrset;
- cfset_ioctl_off(&p);
- cpumask_clear_cpu(cpu, &cfset_request.mask);
+ if (!list_empty(&cfset_session.head)) {
+ list_for_each_entry(rp, &cfset_session.head, node) {
+ p.sets = rp->ctrset;
+ cfset_ioctl_off(&p);
+ cpumask_clear_cpu(cpu, &rp->mask);
+ }
}
mutex_unlock(&cfset_ctrset_mutex);
return 0;
projects / nvme.git / commitdiff