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-rw-r--r--drivers/hwtracing/stm/core.c140
-rw-r--r--drivers/hwtracing/stm/policy.c145
-rw-r--r--drivers/hwtracing/stm/stm.h51
3 files changed, 318 insertions, 18 deletions
diff --git a/drivers/hwtracing/stm/core.c b/drivers/hwtracing/stm/core.c
index 17198e79df3e..915af2541dcd 100644
--- a/drivers/hwtracing/stm/core.c
+++ b/drivers/hwtracing/stm/core.c
@@ -316,11 +316,26 @@ static int stm_output_assign(struct stm_device *stm, unsigned int width,
output->master = midx;
output->channel = cidx;
output->nr_chans = width;
+ if (stm->pdrv->output_open) {
+ void *priv = stp_policy_node_priv(policy_node);
+
+ if (WARN_ON_ONCE(!priv))
+ goto unlock;
+
+ /* configfs subsys mutex is held by the caller */
+ ret = stm->pdrv->output_open(priv, output);
+ if (ret)
+ goto unlock;
+ }
+
stm_output_claim(stm, output);
dev_dbg(&stm->dev, "assigned %u:%u (+%u)\n", midx, cidx, width);
ret = 0;
unlock:
+ if (ret)
+ output->nr_chans = 0;
+
spin_unlock(&output->lock);
spin_unlock(&stm->mc_lock);
@@ -333,6 +348,8 @@ static void stm_output_free(struct stm_device *stm, struct stm_output *output)
spin_lock(&output->lock);
if (output->nr_chans)
stm_output_disclaim(stm, output);
+ if (stm->pdrv && stm->pdrv->output_close)
+ stm->pdrv->output_close(output);
spin_unlock(&output->lock);
spin_unlock(&stm->mc_lock);
}
@@ -349,6 +366,127 @@ static int major_match(struct device *dev, const void *data)
return MAJOR(dev->devt) == major;
}
+/*
+ * Framing protocol management
+ * Modules can implement STM protocol drivers and (un-)register them
+ * with the STM class framework.
+ */
+static struct list_head stm_pdrv_head;
+static struct mutex stm_pdrv_mutex;
+
+struct stm_pdrv_entry {
+ struct list_head entry;
+ const struct stm_protocol_driver *pdrv;
+ const struct config_item_type *node_type;
+};
+
+static const struct stm_pdrv_entry *
+__stm_lookup_protocol(const char *name)
+{
+ struct stm_pdrv_entry *pe;
+
+ /*
+ * If no name is given (NULL or ""), fall back to "p_basic".
+ */
+ if (!name || !*name)
+ name = "p_basic";
+
+ list_for_each_entry(pe, &stm_pdrv_head, entry) {
+ if (!strcmp(name, pe->pdrv->name))
+ return pe;
+ }
+
+ return NULL;
+}
+
+int stm_register_protocol(const struct stm_protocol_driver *pdrv)
+{
+ struct stm_pdrv_entry *pe = NULL;
+ int ret = -ENOMEM;
+
+ mutex_lock(&stm_pdrv_mutex);
+
+ if (__stm_lookup_protocol(pdrv->name)) {
+ ret = -EEXIST;
+ goto unlock;
+ }
+
+ pe = kzalloc(sizeof(*pe), GFP_KERNEL);
+ if (!pe)
+ goto unlock;
+
+ if (pdrv->policy_attr) {
+ pe->node_type = get_policy_node_type(pdrv->policy_attr);
+ if (!pe->node_type)
+ goto unlock;
+ }
+
+ list_add_tail(&pe->entry, &stm_pdrv_head);
+ pe->pdrv = pdrv;
+
+ ret = 0;
+unlock:
+ mutex_unlock(&stm_pdrv_mutex);
+
+ if (ret)
+ kfree(pe);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(stm_register_protocol);
+
+void stm_unregister_protocol(const struct stm_protocol_driver *pdrv)
+{
+ struct stm_pdrv_entry *pe, *iter;
+
+ mutex_lock(&stm_pdrv_mutex);
+
+ list_for_each_entry_safe(pe, iter, &stm_pdrv_head, entry) {
+ if (pe->pdrv == pdrv) {
+ list_del(&pe->entry);
+
+ if (pe->node_type) {
+ kfree(pe->node_type->ct_attrs);
+ kfree(pe->node_type);
+ }
+ kfree(pe);
+ break;
+ }
+ }
+
+ mutex_unlock(&stm_pdrv_mutex);
+}
+EXPORT_SYMBOL_GPL(stm_unregister_protocol);
+
+static bool stm_get_protocol(const struct stm_protocol_driver *pdrv)
+{
+ return try_module_get(pdrv->owner);
+}
+
+void stm_put_protocol(const struct stm_protocol_driver *pdrv)
+{
+ module_put(pdrv->owner);
+}
+
+int stm_lookup_protocol(const char *name,
+ const struct stm_protocol_driver **pdrv,
+ const struct config_item_type **node_type)
+{
+ const struct stm_pdrv_entry *pe;
+
+ mutex_lock(&stm_pdrv_mutex);
+
+ pe = __stm_lookup_protocol(name);
+ if (pe && pe->pdrv && stm_get_protocol(pe->pdrv)) {
+ *pdrv = pe->pdrv;
+ *node_type = pe->node_type;
+ }
+
+ mutex_unlock(&stm_pdrv_mutex);
+
+ return pe ? 0 : -ENOENT;
+}
+
static int stm_char_open(struct inode *inode, struct file *file)
{
struct stm_file *stmf;
@@ -1176,6 +1314,8 @@ static int __init stm_core_init(void)
goto err_src;
init_srcu_struct(&stm_source_srcu);
+ INIT_LIST_HEAD(&stm_pdrv_head);
+ mutex_init(&stm_pdrv_mutex);
stm_core_up++;
diff --git a/drivers/hwtracing/stm/policy.c b/drivers/hwtracing/stm/policy.c
index a505f055f464..8bc90432ae69 100644
--- a/drivers/hwtracing/stm/policy.c
+++ b/drivers/hwtracing/stm/policy.c
@@ -33,8 +33,18 @@ struct stp_policy_node {
unsigned int last_master;
unsigned int first_channel;
unsigned int last_channel;
+ /* this is the one that's exposed to the attributes */
+ unsigned char priv[0];
};
+void *stp_policy_node_priv(struct stp_policy_node *pn)
+{
+ if (!pn)
+ return NULL;
+
+ return pn->priv;
+}
+
static struct configfs_subsystem stp_policy_subsys;
void stp_policy_node_get_ranges(struct stp_policy_node *policy_node,
@@ -68,6 +78,14 @@ to_stp_policy_node(struct config_item *item)
NULL;
}
+void *to_pdrv_policy_node(struct config_item *item)
+{
+ struct stp_policy_node *node = to_stp_policy_node(item);
+
+ return stp_policy_node_priv(node);
+}
+EXPORT_SYMBOL_GPL(to_pdrv_policy_node);
+
static ssize_t
stp_policy_node_masters_show(struct config_item *item, char *page)
{
@@ -163,7 +181,9 @@ unlock:
static void stp_policy_node_release(struct config_item *item)
{
- kfree(to_stp_policy_node(item));
+ struct stp_policy_node *node = to_stp_policy_node(item);
+
+ kfree(node);
}
static struct configfs_item_operations stp_policy_node_item_ops = {
@@ -182,10 +202,61 @@ static struct configfs_attribute *stp_policy_node_attrs[] = {
static const struct config_item_type stp_policy_type;
static const struct config_item_type stp_policy_node_type;
+/* lifted from arch/x86/events/core.c */
+static struct configfs_attribute **merge_attr(struct configfs_attribute **a, struct configfs_attribute **b)
+{
+ struct configfs_attribute **new;
+ int j, i;
+
+ for (j = 0; a[j]; j++)
+ ;
+ for (i = 0; b[i]; i++)
+ j++;
+ j++;
+
+ new = kmalloc_array(j, sizeof(struct configfs_attribute *),
+ GFP_KERNEL);
+ if (!new)
+ return NULL;
+
+ j = 0;
+ for (i = 0; a[i]; i++)
+ new[j++] = a[i];
+ for (i = 0; b[i]; i++)
+ new[j++] = b[i];
+ new[j] = NULL;
+
+ return new;
+}
+
+const struct config_item_type *
+get_policy_node_type(struct configfs_attribute **attrs)
+{
+ struct config_item_type *type;
+ struct configfs_attribute **merged;
+
+ type = kmemdup(&stp_policy_node_type, sizeof(stp_policy_node_type),
+ GFP_KERNEL);
+ if (!type)
+ return NULL;
+
+ merged = merge_attr(stp_policy_node_attrs, attrs);
+ if (!merged) {
+ kfree(type);
+ return NULL;
+ }
+
+ type->ct_attrs = merged;
+
+ return type;
+}
+
static struct config_group *
stp_policy_node_make(struct config_group *group, const char *name)
{
+ const struct config_item_type *type = &stp_policy_node_type;
struct stp_policy_node *policy_node, *parent_node;
+ const struct stm_protocol_driver *pdrv;
struct stp_policy *policy;
if (group->cg_item.ci_type == &stp_policy_type) {
@@ -199,12 +270,20 @@ stp_policy_node_make(struct config_group *group, const char *name)
if (!policy->stm)
return ERR_PTR(-ENODEV);
- policy_node = kzalloc(sizeof(struct stp_policy_node), GFP_KERNEL);
+ pdrv = policy->stm->pdrv;
+ policy_node =
+ kzalloc(offsetof(struct stp_policy_node, priv[pdrv->priv_sz]),
+ GFP_KERNEL);
if (!policy_node)
return ERR_PTR(-ENOMEM);
- config_group_init_type_name(&policy_node->group, name,
- &stp_policy_node_type);
+ if (pdrv->policy_node_init)
+ pdrv->policy_node_init((void *)policy_node->priv);
+
+ if (policy->stm->pdrv_node_type)
+ type = policy->stm->pdrv_node_type;
+
+ config_group_init_type_name(&policy_node->group, name, type);
policy_node->policy = policy;
@@ -254,8 +333,25 @@ static ssize_t stp_policy_device_show(struct config_item *item,
CONFIGFS_ATTR_RO(stp_policy_, device);
+static ssize_t stp_policy_protocol_show(struct config_item *item,
+ char *page)
+{
+ struct stp_policy *policy = to_stp_policy(item);
+ ssize_t count;
+
+ count = sprintf(page, "%s\n",
+ (policy && policy->stm) ?
+ policy->stm->pdrv->name :
+ "<none>");
+
+ return count;
+}
+
+CONFIGFS_ATTR_RO(stp_policy_, protocol);
+
static struct configfs_attribute *stp_policy_attrs[] = {
&stp_policy_attr_device,
+ &stp_policy_attr_protocol,
NULL,
};
@@ -276,6 +372,7 @@ void stp_policy_unbind(struct stp_policy *policy)
stm->policy = NULL;
policy->stm = NULL;
+ stm_put_protocol(stm->pdrv);
stm_put_device(stm);
}
@@ -313,9 +410,12 @@ static const struct config_item_type stp_policy_type = {
static struct config_group *
stp_policy_make(struct config_group *group, const char *name)
{
+ const struct config_item_type *pdrv_node_type;
+ const struct stm_protocol_driver *pdrv;
+ char *devname, *proto, *p;
struct config_group *ret;
struct stm_device *stm;
- char *devname, *p;
+ int err;
devname = kasprintf(GFP_KERNEL, "%s", name);
if (!devname)
@@ -326,6 +426,7 @@ stp_policy_make(struct config_group *group, const char *name)
* <device_name> is the name of an existing stm device; may
* contain dots;
* <policy_name> is an arbitrary string; may not contain dots
+ * <device_name>:<protocol_name>.<policy_name>
*/
p = strrchr(devname, '.');
if (!p) {
@@ -335,11 +436,29 @@ stp_policy_make(struct config_group *group, const char *name)
*p = '\0';
+ /*
+ * look for ":<protocol_name>":
+ * + no protocol suffix: fall back to whatever is available;
+ * + unknown protocol: fail the whole thing
+ */
+ proto = strrchr(devname, ':');
+ if (proto)
+ *proto++ = '\0';
+
stm = stm_find_device(devname);
+ if (!stm) {
+ kfree(devname);
+ return ERR_PTR(-ENODEV);
+ }
+
+ err = stm_lookup_protocol(proto, &pdrv, &pdrv_node_type);
kfree(devname);
- if (!stm)
+ /* We don't have any protocol drivers yet */
+ if (err != -ENOENT) {
+ stm_put_device(stm);
return ERR_PTR(-ENODEV);
+ }
mutex_lock(&stm->policy_mutex);
if (stm->policy) {
@@ -349,21 +468,27 @@ stp_policy_make(struct config_group *group, const char *name)
stm->policy = kzalloc(sizeof(*stm->policy), GFP_KERNEL);
if (!stm->policy) {
- ret = ERR_PTR(-ENOMEM);
- goto unlock_policy;
+ mutex_unlock(&stm->policy_mutex);
+ stm_put_protocol(pdrv);
+ stm_put_device(stm);
+ return ERR_PTR(-ENOMEM);
}
config_group_init_type_name(&stm->policy->group, name,
&stp_policy_type);
- stm->policy->stm = stm;
+ stm->pdrv = pdrv;
+ stm->pdrv_node_type = pdrv_node_type;
+ stm->policy->stm = stm;
ret = &stm->policy->group;
unlock_policy:
mutex_unlock(&stm->policy_mutex);
- if (IS_ERR(ret))
+ if (IS_ERR(ret)) {
+ stm_put_protocol(stm->pdrv);
stm_put_device(stm);
+ }
return ret;
}
diff --git a/drivers/hwtracing/stm/stm.h b/drivers/hwtracing/stm/stm.h
index e5df08ae59cf..ed7f3d07fa47 100644
--- a/drivers/hwtracing/stm/stm.h
+++ b/drivers/hwtracing/stm/stm.h
@@ -10,20 +10,17 @@
#ifndef _STM_STM_H_
#define _STM_STM_H_
+#include <linux/configfs.h>
+
struct stp_policy;
struct stp_policy_node;
+struct stm_protocol_driver;
-struct stp_policy_node *
-stp_policy_node_lookup(struct stm_device *stm, char *s);
-void stp_policy_node_put(struct stp_policy_node *policy_node);
-void stp_policy_unbind(struct stp_policy *policy);
-
-void stp_policy_node_get_ranges(struct stp_policy_node *policy_node,
- unsigned int *mstart, unsigned int *mend,
- unsigned int *cstart, unsigned int *cend);
int stp_configfs_init(void);
void stp_configfs_exit(void);
+void *stp_policy_node_priv(struct stp_policy_node *pn);
+
struct stp_master {
unsigned int nr_free;
unsigned long chan_map[0];
@@ -40,6 +37,9 @@ struct stm_device {
struct mutex link_mutex;
spinlock_t link_lock;
struct list_head link_list;
+ /* framing protocol in use */
+ const struct stm_protocol_driver *pdrv;
+ const struct config_item_type *pdrv_node_type;
/* master allocation */
spinlock_t mc_lock;
struct stp_master *masters[0];
@@ -48,11 +48,24 @@ struct stm_device {
#define to_stm_device(_d) \
container_of((_d), struct stm_device, dev)
+struct stp_policy_node *
+stp_policy_node_lookup(struct stm_device *stm, char *s);
+void stp_policy_node_put(struct stp_policy_node *policy_node);
+void stp_policy_unbind(struct stp_policy *policy);
+
+void stp_policy_node_get_ranges(struct stp_policy_node *policy_node,
+ unsigned int *mstart, unsigned int *mend,
+ unsigned int *cstart, unsigned int *cend);
+
+const struct config_item_type *
+get_policy_node_type(struct configfs_attribute **attrs);
+
struct stm_output {
spinlock_t lock;
unsigned int master;
unsigned int channel;
unsigned int nr_chans;
+ void *pdrv_private;
};
struct stm_file {
@@ -76,4 +89,26 @@ struct stm_source_device {
#define to_stm_source_device(_d) \
container_of((_d), struct stm_source_device, dev)
+void *to_pdrv_policy_node(struct config_item *item);
+
+struct stm_protocol_driver {
+ struct module *owner;
+ const char *name;
+ ssize_t (*write)(struct stm_data *data,
+ struct stm_output *output, unsigned int chan,
+ const char *buf, size_t count);
+ void (*policy_node_init)(void *arg);
+ int (*output_open)(void *priv, struct stm_output *output);
+ void (*output_close)(struct stm_output *output);
+ ssize_t priv_sz;
+ struct configfs_attribute **policy_attr;
+};
+
+int stm_register_protocol(const struct stm_protocol_driver *pdrv);
+void stm_unregister_protocol(const struct stm_protocol_driver *pdrv);
+int stm_lookup_protocol(const char *name,
+ const struct stm_protocol_driver **pdrv,
+ const struct config_item_type **type);
+void stm_put_protocol(const struct stm_protocol_driver *pdrv);
+
#endif /* _STM_STM_H_ */
generated by cgit v1.2.3 (git 2.39.0) at 2024-12-20 12:57:27 +0300