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|
/*
* core.c - Implementation of core module of MOST Linux driver stack
*
* Copyright (C) 2013-2015 Microchip Technology Germany II GmbH & Co. KG
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* This file is licensed under GPLv2.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/list.h>
#include <linux/poll.h>
#include <linux/wait.h>
#include <linux/kobject.h>
#include <linux/mutex.h>
#include <linux/completion.h>
#include <linux/sysfs.h>
#include <linux/kthread.h>
#include <linux/dma-mapping.h>
#include <linux/idr.h>
#include "mostcore.h"
#define MAX_CHANNELS 64
#define STRING_SIZE 80
static struct class *most_class;
static struct device *class_glue_dir;
static struct ida mdev_id;
static int dummy_num_buffers;
struct most_c_aim_obj {
struct most_aim *ptr;
int refs;
int num_buffers;
};
struct most_c_obj {
struct kobject kobj;
struct completion cleanup;
atomic_t mbo_ref;
atomic_t mbo_nq_level;
u16 channel_id;
bool is_poisoned;
struct mutex start_mutex;
int is_starving;
struct most_interface *iface;
struct most_inst_obj *inst;
struct most_channel_config cfg;
bool keep_mbo;
bool enqueue_halt;
struct list_head fifo;
spinlock_t fifo_lock;
struct list_head halt_fifo;
struct list_head list;
struct most_c_aim_obj aim0;
struct most_c_aim_obj aim1;
struct list_head trash_fifo;
struct task_struct *hdm_enqueue_task;
struct mutex stop_task_mutex;
wait_queue_head_t hdm_fifo_wq;
};
#define to_c_obj(d) container_of(d, struct most_c_obj, kobj)
struct most_inst_obj {
int dev_id;
struct most_interface *iface;
struct list_head channel_list;
struct most_c_obj *channel[MAX_CHANNELS];
struct kobject kobj;
struct list_head list;
};
#define to_inst_obj(d) container_of(d, struct most_inst_obj, kobj)
/**
* list_pop_mbo - retrieves the first MBO of the list and removes it
* @ptr: the list head to grab the MBO from.
*/
#define list_pop_mbo(ptr) \
({ \
struct mbo *_mbo = list_first_entry(ptr, struct mbo, list); \
list_del(&_mbo->list); \
_mbo; \
})
static struct mutex deregister_mutex;
/* ___ ___
* ___C H A N N E L___
*/
/**
* struct most_c_attr - to access the attributes of a channel object
* @attr: attributes of a channel
* @show: pointer to the show function
* @store: pointer to the store function
*/
struct most_c_attr {
struct attribute attr;
ssize_t (*show)(struct most_c_obj *d,
struct most_c_attr *attr,
char *buf);
ssize_t (*store)(struct most_c_obj *d,
struct most_c_attr *attr,
const char *buf,
size_t count);
};
#define to_channel_attr(a) container_of(a, struct most_c_attr, attr)
#define MOST_CHNL_ATTR(_name, _mode, _show, _store) \
struct most_c_attr most_chnl_attr_##_name = \
__ATTR(_name, _mode, _show, _store)
/**
* channel_attr_show - show function of channel object
* @kobj: pointer to its kobject
* @attr: pointer to its attributes
* @buf: buffer
*/
static ssize_t channel_attr_show(struct kobject *kobj, struct attribute *attr,
char *buf)
{
struct most_c_attr *channel_attr = to_channel_attr(attr);
struct most_c_obj *c_obj = to_c_obj(kobj);
if (!channel_attr->show)
return -EIO;
return channel_attr->show(c_obj, channel_attr, buf);
}
/**
* channel_attr_store - store function of channel object
* @kobj: pointer to its kobject
* @attr: pointer to its attributes
* @buf: buffer
* @len: length of buffer
*/
static ssize_t channel_attr_store(struct kobject *kobj,
struct attribute *attr,
const char *buf,
size_t len)
{
struct most_c_attr *channel_attr = to_channel_attr(attr);
struct most_c_obj *c_obj = to_c_obj(kobj);
if (!channel_attr->store)
return -EIO;
return channel_attr->store(c_obj, channel_attr, buf, len);
}
static const struct sysfs_ops most_channel_sysfs_ops = {
.show = channel_attr_show,
.store = channel_attr_store,
};
/**
* most_free_mbo_coherent - free an MBO and its coherent buffer
* @mbo: buffer to be released
*
*/
static void most_free_mbo_coherent(struct mbo *mbo)
{
struct most_c_obj *c = mbo->context;
u16 const coherent_buf_size = c->cfg.buffer_size + c->cfg.extra_len;
dma_free_coherent(NULL, coherent_buf_size, mbo->virt_address,
mbo->bus_address);
kfree(mbo);
if (atomic_sub_and_test(1, &c->mbo_ref))
complete(&c->cleanup);
}
/**
* flush_channel_fifos - clear the channel fifos
* @c: pointer to channel object
*/
static void flush_channel_fifos(struct most_c_obj *c)
{
unsigned long flags, hf_flags;
struct mbo *mbo, *tmp;
if (list_empty(&c->fifo) && list_empty(&c->halt_fifo))
return;
spin_lock_irqsave(&c->fifo_lock, flags);
list_for_each_entry_safe(mbo, tmp, &c->fifo, list) {
list_del(&mbo->list);
spin_unlock_irqrestore(&c->fifo_lock, flags);
most_free_mbo_coherent(mbo);
spin_lock_irqsave(&c->fifo_lock, flags);
}
spin_unlock_irqrestore(&c->fifo_lock, flags);
spin_lock_irqsave(&c->fifo_lock, hf_flags);
list_for_each_entry_safe(mbo, tmp, &c->halt_fifo, list) {
list_del(&mbo->list);
spin_unlock_irqrestore(&c->fifo_lock, hf_flags);
most_free_mbo_coherent(mbo);
spin_lock_irqsave(&c->fifo_lock, hf_flags);
}
spin_unlock_irqrestore(&c->fifo_lock, hf_flags);
if (unlikely((!list_empty(&c->fifo) || !list_empty(&c->halt_fifo))))
pr_info("WARN: fifo | trash fifo not empty\n");
}
/**
* flush_trash_fifo - clear the trash fifo
* @c: pointer to channel object
*/
static int flush_trash_fifo(struct most_c_obj *c)
{
struct mbo *mbo, *tmp;
unsigned long flags;
spin_lock_irqsave(&c->fifo_lock, flags);
list_for_each_entry_safe(mbo, tmp, &c->trash_fifo, list) {
list_del(&mbo->list);
spin_unlock_irqrestore(&c->fifo_lock, flags);
most_free_mbo_coherent(mbo);
spin_lock_irqsave(&c->fifo_lock, flags);
}
spin_unlock_irqrestore(&c->fifo_lock, flags);
return 0;
}
/**
* most_channel_release - release function of channel object
* @kobj: pointer to channel's kobject
*/
static void most_channel_release(struct kobject *kobj)
{
struct most_c_obj *c = to_c_obj(kobj);
kfree(c);
}
static ssize_t show_available_directions(struct most_c_obj *c,
struct most_c_attr *attr,
char *buf)
{
unsigned int i = c->channel_id;
strcpy(buf, "");
if (c->iface->channel_vector[i].direction & MOST_CH_RX)
strcat(buf, "dir_rx ");
if (c->iface->channel_vector[i].direction & MOST_CH_TX)
strcat(buf, "dir_tx ");
strcat(buf, "\n");
return strlen(buf) + 1;
}
static ssize_t show_available_datatypes(struct most_c_obj *c,
struct most_c_attr *attr,
char *buf)
{
unsigned int i = c->channel_id;
strcpy(buf, "");
if (c->iface->channel_vector[i].data_type & MOST_CH_CONTROL)
strcat(buf, "control ");
if (c->iface->channel_vector[i].data_type & MOST_CH_ASYNC)
strcat(buf, "async ");
if (c->iface->channel_vector[i].data_type & MOST_CH_SYNC)
strcat(buf, "sync ");
if (c->iface->channel_vector[i].data_type & MOST_CH_ISOC_AVP)
strcat(buf, "isoc_avp ");
strcat(buf, "\n");
return strlen(buf) + 1;
}
static
ssize_t show_number_of_packet_buffers(struct most_c_obj *c,
struct most_c_attr *attr,
char *buf)
{
unsigned int i = c->channel_id;
return snprintf(buf, PAGE_SIZE, "%d\n",
c->iface->channel_vector[i].num_buffers_packet);
}
static
ssize_t show_number_of_stream_buffers(struct most_c_obj *c,
struct most_c_attr *attr,
char *buf)
{
unsigned int i = c->channel_id;
return snprintf(buf, PAGE_SIZE, "%d\n",
c->iface->channel_vector[i].num_buffers_streaming);
}
static
ssize_t show_size_of_packet_buffer(struct most_c_obj *c,
struct most_c_attr *attr,
char *buf)
{
unsigned int i = c->channel_id;
return snprintf(buf, PAGE_SIZE, "%d\n",
c->iface->channel_vector[i].buffer_size_packet);
}
static
ssize_t show_size_of_stream_buffer(struct most_c_obj *c,
struct most_c_attr *attr,
char *buf)
{
unsigned int i = c->channel_id;
return snprintf(buf, PAGE_SIZE, "%d\n",
c->iface->channel_vector[i].buffer_size_streaming);
}
static ssize_t show_channel_starving(struct most_c_obj *c,
struct most_c_attr *attr,
char *buf)
{
return snprintf(buf, PAGE_SIZE, "%d\n", c->is_starving);
}
#define create_show_channel_attribute(val) \
static MOST_CHNL_ATTR(val, S_IRUGO, show_##val, NULL)
create_show_channel_attribute(available_directions);
create_show_channel_attribute(available_datatypes);
create_show_channel_attribute(number_of_packet_buffers);
create_show_channel_attribute(number_of_stream_buffers);
create_show_channel_attribute(size_of_stream_buffer);
create_show_channel_attribute(size_of_packet_buffer);
create_show_channel_attribute(channel_starving);
static ssize_t show_set_number_of_buffers(struct most_c_obj *c,
struct most_c_attr *attr,
char *buf)
{
return snprintf(buf, PAGE_SIZE, "%d\n", c->cfg.num_buffers);
}
static ssize_t store_set_number_of_buffers(struct most_c_obj *c,
struct most_c_attr *attr,
const char *buf,
size_t count)
{
int ret = kstrtou16(buf, 0, &c->cfg.num_buffers);
if (ret)
return ret;
return count;
}
static ssize_t show_set_buffer_size(struct most_c_obj *c,
struct most_c_attr *attr,
char *buf)
{
return snprintf(buf, PAGE_SIZE, "%d\n", c->cfg.buffer_size);
}
static ssize_t store_set_buffer_size(struct most_c_obj *c,
struct most_c_attr *attr,
const char *buf,
size_t count)
{
int ret = kstrtou16(buf, 0, &c->cfg.buffer_size);
if (ret)
return ret;
return count;
}
static ssize_t show_set_direction(struct most_c_obj *c,
struct most_c_attr *attr,
char *buf)
{
if (c->cfg.direction & MOST_CH_TX)
return snprintf(buf, PAGE_SIZE, "dir_tx\n");
else if (c->cfg.direction & MOST_CH_RX)
return snprintf(buf, PAGE_SIZE, "dir_rx\n");
return snprintf(buf, PAGE_SIZE, "unconfigured\n");
}
static ssize_t store_set_direction(struct most_c_obj *c,
struct most_c_attr *attr,
const char *buf,
size_t count)
{
if (!strcmp(buf, "dir_rx\n")) {
c->cfg.direction = MOST_CH_RX;
} else if (!strcmp(buf, "dir_tx\n")) {
c->cfg.direction = MOST_CH_TX;
} else {
pr_info("WARN: invalid attribute settings\n");
return -EINVAL;
}
return count;
}
static ssize_t show_set_datatype(struct most_c_obj *c,
struct most_c_attr *attr,
char *buf)
{
if (c->cfg.data_type & MOST_CH_CONTROL)
return snprintf(buf, PAGE_SIZE, "control\n");
else if (c->cfg.data_type & MOST_CH_ASYNC)
return snprintf(buf, PAGE_SIZE, "async\n");
else if (c->cfg.data_type & MOST_CH_SYNC)
return snprintf(buf, PAGE_SIZE, "sync\n");
else if (c->cfg.data_type & MOST_CH_ISOC_AVP)
return snprintf(buf, PAGE_SIZE, "isoc_avp\n");
return snprintf(buf, PAGE_SIZE, "unconfigured\n");
}
static ssize_t store_set_datatype(struct most_c_obj *c,
struct most_c_attr *attr,
const char *buf,
size_t count)
{
if (!strcmp(buf, "control\n")) {
c->cfg.data_type = MOST_CH_CONTROL;
} else if (!strcmp(buf, "async\n")) {
c->cfg.data_type = MOST_CH_ASYNC;
} else if (!strcmp(buf, "sync\n")) {
c->cfg.data_type = MOST_CH_SYNC;
} else if (!strcmp(buf, "isoc_avp\n")) {
c->cfg.data_type = MOST_CH_ISOC_AVP;
} else {
pr_info("WARN: invalid attribute settings\n");
return -EINVAL;
}
return count;
}
static ssize_t show_set_subbuffer_size(struct most_c_obj *c,
struct most_c_attr *attr,
char *buf)
{
return snprintf(buf, PAGE_SIZE, "%d\n", c->cfg.subbuffer_size);
}
static ssize_t store_set_subbuffer_size(struct most_c_obj *c,
struct most_c_attr *attr,
const char *buf,
size_t count)
{
int ret = kstrtou16(buf, 0, &c->cfg.subbuffer_size);
if (ret)
return ret;
return count;
}
static ssize_t show_set_packets_per_xact(struct most_c_obj *c,
struct most_c_attr *attr,
char *buf)
{
return snprintf(buf, PAGE_SIZE, "%d\n", c->cfg.packets_per_xact);
}
static ssize_t store_set_packets_per_xact(struct most_c_obj *c,
struct most_c_attr *attr,
const char *buf,
size_t count)
{
int ret = kstrtou16(buf, 0, &c->cfg.packets_per_xact);
if (ret)
return ret;
return count;
}
#define create_channel_attribute(value) \
static MOST_CHNL_ATTR(value, S_IRUGO | S_IWUSR, \
show_##value, \
store_##value)
create_channel_attribute(set_buffer_size);
create_channel_attribute(set_number_of_buffers);
create_channel_attribute(set_direction);
create_channel_attribute(set_datatype);
create_channel_attribute(set_subbuffer_size);
create_channel_attribute(set_packets_per_xact);
/**
* most_channel_def_attrs - array of default attributes of channel object
*/
static struct attribute *most_channel_def_attrs[] = {
&most_chnl_attr_available_directions.attr,
&most_chnl_attr_available_datatypes.attr,
&most_chnl_attr_number_of_packet_buffers.attr,
&most_chnl_attr_number_of_stream_buffers.attr,
&most_chnl_attr_size_of_packet_buffer.attr,
&most_chnl_attr_size_of_stream_buffer.attr,
&most_chnl_attr_set_number_of_buffers.attr,
&most_chnl_attr_set_buffer_size.attr,
&most_chnl_attr_set_direction.attr,
&most_chnl_attr_set_datatype.attr,
&most_chnl_attr_set_subbuffer_size.attr,
&most_chnl_attr_set_packets_per_xact.attr,
&most_chnl_attr_channel_starving.attr,
NULL,
};
static struct kobj_type most_channel_ktype = {
.sysfs_ops = &most_channel_sysfs_ops,
.release = most_channel_release,
.default_attrs = most_channel_def_attrs,
};
static struct kset *most_channel_kset;
/**
* create_most_c_obj - allocates a channel object
* @name: name of the channel object
* @parent: parent kobject
*
* This create a channel object and registers it with sysfs.
* Returns a pointer to the object or NULL when something went wrong.
*/
static struct most_c_obj *
create_most_c_obj(const char *name, struct kobject *parent)
{
struct most_c_obj *c;
int retval;
c = kzalloc(sizeof(*c), GFP_KERNEL);
if (!c)
return NULL;
c->kobj.kset = most_channel_kset;
retval = kobject_init_and_add(&c->kobj, &most_channel_ktype, parent,
"%s", name);
if (retval) {
kobject_put(&c->kobj);
return NULL;
}
kobject_uevent(&c->kobj, KOBJ_ADD);
return c;
}
/* ___ ___
* ___I N S T A N C E___
*/
#define MOST_INST_ATTR(_name, _mode, _show, _store) \
struct most_inst_attribute most_inst_attr_##_name = \
__ATTR(_name, _mode, _show, _store)
static struct list_head instance_list;
/**
* struct most_inst_attribute - to access the attributes of instance object
* @attr: attributes of an instance
* @show: pointer to the show function
* @store: pointer to the store function
*/
struct most_inst_attribute {
struct attribute attr;
ssize_t (*show)(struct most_inst_obj *d,
struct most_inst_attribute *attr,
char *buf);
ssize_t (*store)(struct most_inst_obj *d,
struct most_inst_attribute *attr,
const char *buf,
size_t count);
};
#define to_instance_attr(a) \
container_of(a, struct most_inst_attribute, attr)
/**
* instance_attr_show - show function for an instance object
* @kobj: pointer to kobject
* @attr: pointer to attribute struct
* @buf: buffer
*/
static ssize_t instance_attr_show(struct kobject *kobj,
struct attribute *attr,
char *buf)
{
struct most_inst_attribute *instance_attr;
struct most_inst_obj *instance_obj;
instance_attr = to_instance_attr(attr);
instance_obj = to_inst_obj(kobj);
if (!instance_attr->show)
return -EIO;
return instance_attr->show(instance_obj, instance_attr, buf);
}
/**
* instance_attr_store - store function for an instance object
* @kobj: pointer to kobject
* @attr: pointer to attribute struct
* @buf: buffer
* @len: length of buffer
*/
static ssize_t instance_attr_store(struct kobject *kobj,
struct attribute *attr,
const char *buf,
size_t len)
{
struct most_inst_attribute *instance_attr;
struct most_inst_obj *instance_obj;
instance_attr = to_instance_attr(attr);
instance_obj = to_inst_obj(kobj);
if (!instance_attr->store)
return -EIO;
return instance_attr->store(instance_obj, instance_attr, buf, len);
}
static const struct sysfs_ops most_inst_sysfs_ops = {
.show = instance_attr_show,
.store = instance_attr_store,
};
/**
* most_inst_release - release function for instance object
* @kobj: pointer to instance's kobject
*
* This frees the allocated memory for the instance object
*/
static void most_inst_release(struct kobject *kobj)
{
struct most_inst_obj *inst = to_inst_obj(kobj);
kfree(inst);
}
static ssize_t show_description(struct most_inst_obj *instance_obj,
struct most_inst_attribute *attr,
char *buf)
{
return snprintf(buf, PAGE_SIZE, "%s\n",
instance_obj->iface->description);
}
static ssize_t show_interface(struct most_inst_obj *instance_obj,
struct most_inst_attribute *attr,
char *buf)
{
switch (instance_obj->iface->interface) {
case ITYPE_LOOPBACK:
return snprintf(buf, PAGE_SIZE, "loopback\n");
case ITYPE_I2C:
return snprintf(buf, PAGE_SIZE, "i2c\n");
case ITYPE_I2S:
return snprintf(buf, PAGE_SIZE, "i2s\n");
case ITYPE_TSI:
return snprintf(buf, PAGE_SIZE, "tsi\n");
case ITYPE_HBI:
return snprintf(buf, PAGE_SIZE, "hbi\n");
case ITYPE_MEDIALB_DIM:
return snprintf(buf, PAGE_SIZE, "mlb_dim\n");
case ITYPE_MEDIALB_DIM2:
return snprintf(buf, PAGE_SIZE, "mlb_dim2\n");
case ITYPE_USB:
return snprintf(buf, PAGE_SIZE, "usb\n");
case ITYPE_PCIE:
return snprintf(buf, PAGE_SIZE, "pcie\n");
}
return snprintf(buf, PAGE_SIZE, "unknown\n");
}
#define create_inst_attribute(value) \
static MOST_INST_ATTR(value, S_IRUGO, show_##value, NULL)
create_inst_attribute(description);
create_inst_attribute(interface);
static struct attribute *most_inst_def_attrs[] = {
&most_inst_attr_description.attr,
&most_inst_attr_interface.attr,
NULL,
};
static struct kobj_type most_inst_ktype = {
.sysfs_ops = &most_inst_sysfs_ops,
.release = most_inst_release,
.default_attrs = most_inst_def_attrs,
};
static struct kset *most_inst_kset;
/**
* create_most_inst_obj - creates an instance object
* @name: name of the object to be created
*
* This allocates memory for an instance structure, assigns the proper kset
* and registers it with sysfs.
*
* Returns a pointer to the instance object or NULL when something went wrong.
*/
static struct most_inst_obj *create_most_inst_obj(const char *name)
{
struct most_inst_obj *inst;
int retval;
inst = kzalloc(sizeof(*inst), GFP_KERNEL);
if (!inst)
return NULL;
inst->kobj.kset = most_inst_kset;
retval = kobject_init_and_add(&inst->kobj, &most_inst_ktype, NULL,
"%s", name);
if (retval) {
kobject_put(&inst->kobj);
return NULL;
}
kobject_uevent(&inst->kobj, KOBJ_ADD);
return inst;
}
/**
* destroy_most_inst_obj - MOST instance release function
* @inst: pointer to the instance object
*
* This decrements the reference counter of the instance object.
* If the reference count turns zero, its release function is called
*/
static void destroy_most_inst_obj(struct most_inst_obj *inst)
{
struct most_c_obj *c, *tmp;
list_for_each_entry_safe(c, tmp, &inst->channel_list, list) {
mutex_lock(&deregister_mutex);
flush_trash_fifo(c);
flush_channel_fifos(c);
mutex_unlock(&deregister_mutex);
kobject_put(&c->kobj);
}
kobject_put(&inst->kobj);
}
/* ___ ___
* ___A I M___
*/
struct most_aim_obj {
struct kobject kobj;
struct list_head list;
struct most_aim *driver;
char add_link[STRING_SIZE];
char remove_link[STRING_SIZE];
};
#define to_aim_obj(d) container_of(d, struct most_aim_obj, kobj)
static struct list_head aim_list;
/**
* struct most_aim_attribute - to access the attributes of AIM object
* @attr: attributes of an AIM
* @show: pointer to the show function
* @store: pointer to the store function
*/
struct most_aim_attribute {
struct attribute attr;
ssize_t (*show)(struct most_aim_obj *d,
struct most_aim_attribute *attr,
char *buf);
ssize_t (*store)(struct most_aim_obj *d,
struct most_aim_attribute *attr,
const char *buf,
size_t count);
};
#define to_aim_attr(a) container_of(a, struct most_aim_attribute, attr)
/**
* aim_attr_show - show function of an AIM object
* @kobj: pointer to kobject
* @attr: pointer to attribute struct
* @buf: buffer
*/
static ssize_t aim_attr_show(struct kobject *kobj,
struct attribute *attr,
char *buf)
{
struct most_aim_attribute *aim_attr;
struct most_aim_obj *aim_obj;
aim_attr = to_aim_attr(attr);
aim_obj = to_aim_obj(kobj);
if (!aim_attr->show)
return -EIO;
return aim_attr->show(aim_obj, aim_attr, buf);
}
/**
* aim_attr_store - store function of an AIM object
* @kobj: pointer to kobject
* @attr: pointer to attribute struct
* @buf: buffer
* @len: length of buffer
*/
static ssize_t aim_attr_store(struct kobject *kobj,
struct attribute *attr,
const char *buf,
size_t len)
{
struct most_aim_attribute *aim_attr;
struct most_aim_obj *aim_obj;
aim_attr = to_aim_attr(attr);
aim_obj = to_aim_obj(kobj);
if (!aim_attr->store)
return -EIO;
return aim_attr->store(aim_obj, aim_attr, buf, len);
}
static const struct sysfs_ops most_aim_sysfs_ops = {
.show = aim_attr_show,
.store = aim_attr_store,
};
/**
* most_aim_release - AIM release function
* @kobj: pointer to AIM's kobject
*/
static void most_aim_release(struct kobject *kobj)
{
struct most_aim_obj *aim_obj = to_aim_obj(kobj);
kfree(aim_obj);
}
static ssize_t show_add_link(struct most_aim_obj *aim_obj,
struct most_aim_attribute *attr,
char *buf)
{
return snprintf(buf, PAGE_SIZE, "%s\n", aim_obj->add_link);
}
/**
* split_string - parses and changes string in the buffer buf and
* splits it into two mandatory and one optional substrings.
*
* @buf: complete string from attribute 'add_channel'
* @a: address of pointer to 1st substring (=instance name)
* @b: address of pointer to 2nd substring (=channel name)
* @c: optional address of pointer to 3rd substring (=user defined name)
*
* Examples:
*
* Input: "mdev0:ch0@ep_81:my_channel\n" or
* "mdev0:ch0@ep_81:my_channel"
*
* Output: *a -> "mdev0", *b -> "ch0@ep_81", *c -> "my_channel"
*
* Input: "mdev0:ch0@ep_81\n"
* Output: *a -> "mdev0", *b -> "ch0@ep_81", *c -> ""
*
* Input: "mdev0:ch0@ep_81"
* Output: *a -> "mdev0", *b -> "ch0@ep_81", *c == NULL
*/
static int split_string(char *buf, char **a, char **b, char **c)
{
*a = strsep(&buf, ":");
if (!*a)
return -EIO;
*b = strsep(&buf, ":\n");
if (!*b)
return -EIO;
if (c)
*c = strsep(&buf, ":\n");
return 0;
}
/**
* get_channel_by_name - get pointer to channel object
* @mdev: name of the device instance
* @mdev_ch: name of the respective channel
*
* This retrieves the pointer to a channel object.
*/
static struct
most_c_obj *get_channel_by_name(char *mdev, char *mdev_ch)
{
struct most_c_obj *c, *tmp;
struct most_inst_obj *i, *i_tmp;
int found = 0;
list_for_each_entry_safe(i, i_tmp, &instance_list, list) {
if (!strcmp(kobject_name(&i->kobj), mdev)) {
found++;
break;
}
}
if (unlikely(!found))
return ERR_PTR(-EIO);
list_for_each_entry_safe(c, tmp, &i->channel_list, list) {
if (!strcmp(kobject_name(&c->kobj), mdev_ch)) {
found++;
break;
}
}
if (unlikely(found < 2))
return ERR_PTR(-EIO);
return c;
}
/**
* store_add_link - store() function for add_link attribute
* @aim_obj: pointer to AIM object
* @attr: its attributes
* @buf: buffer
* @len: buffer length
*
* This parses the string given by buf and splits it into
* three substrings. Note: third substring is optional. In case a cdev
* AIM is loaded the optional 3rd substring will make up the name of
* device node in the /dev directory. If omitted, the device node will
* inherit the channel's name within sysfs.
*
* Searches for a pair of device and channel and probes the AIM
*
* Example:
* (1) echo -n -e "mdev0:ch0@ep_81:my_rxchannel\n" >add_link
* (2) echo -n -e "mdev0:ch0@ep_81\n" >add_link
*
* (1) would create the device node /dev/my_rxchannel
* (2) would create the device node /dev/mdev0-ch0@ep_81
*/
static ssize_t store_add_link(struct most_aim_obj *aim_obj,
struct most_aim_attribute *attr,
const char *buf,
size_t len)
{
struct most_c_obj *c;
struct most_aim **aim_ptr;
char buffer[STRING_SIZE];
char *mdev;
char *mdev_ch;
char *mdev_devnod;
char devnod_buf[STRING_SIZE];
int ret;
size_t max_len = min_t(size_t, len + 1, STRING_SIZE);
strlcpy(buffer, buf, max_len);
strlcpy(aim_obj->add_link, buf, max_len);
ret = split_string(buffer, &mdev, &mdev_ch, &mdev_devnod);
if (ret)
return ret;
if (!mdev_devnod || *mdev_devnod == 0) {
snprintf(devnod_buf, sizeof(devnod_buf), "%s-%s", mdev,
mdev_ch);
mdev_devnod = devnod_buf;
}
c = get_channel_by_name(mdev, mdev_ch);
if (IS_ERR(c))
return -ENODEV;
if (!c->aim0.ptr)
aim_ptr = &c->aim0.ptr;
else if (!c->aim1.ptr)
aim_ptr = &c->aim1.ptr;
else
return -ENOSPC;
*aim_ptr = aim_obj->driver;
ret = aim_obj->driver->probe_channel(c->iface, c->channel_id,
&c->cfg, &c->kobj, mdev_devnod);
if (ret) {
*aim_ptr = NULL;
return ret;
}
return len;
}
static struct most_aim_attribute most_aim_attr_add_link =
__ATTR(add_link, S_IRUGO | S_IWUSR, show_add_link, store_add_link);
static ssize_t show_remove_link(struct most_aim_obj *aim_obj,
struct most_aim_attribute *attr,
char *buf)
{
return snprintf(buf, PAGE_SIZE, "%s\n", aim_obj->remove_link);
}
/**
* store_remove_link - store function for remove_link attribute
* @aim_obj: pointer to AIM object
* @attr: its attributes
* @buf: buffer
* @len: buffer length
*
* Example:
* echo -n -e "mdev0:ch0@ep_81\n" >remove_link
*/
static ssize_t store_remove_link(struct most_aim_obj *aim_obj,
struct most_aim_attribute *attr,
const char *buf,
size_t len)
{
struct most_c_obj *c;
char buffer[STRING_SIZE];
char *mdev;
char *mdev_ch;
int ret;
size_t max_len = min_t(size_t, len + 1, STRING_SIZE);
strlcpy(buffer, buf, max_len);
strlcpy(aim_obj->remove_link, buf, max_len);
ret = split_string(buffer, &mdev, &mdev_ch, NULL);
if (ret)
return ret;
c = get_channel_by_name(mdev, mdev_ch);
if (IS_ERR(c))
return -ENODEV;
if (aim_obj->driver->disconnect_channel(c->iface, c->channel_id))
return -EIO;
if (c->aim0.ptr == aim_obj->driver)
c->aim0.ptr = NULL;
if (c->aim1.ptr == aim_obj->driver)
c->aim1.ptr = NULL;
return len;
}
static struct most_aim_attribute most_aim_attr_remove_link =
__ATTR(remove_link, S_IRUGO | S_IWUSR, show_remove_link,
store_remove_link);
static struct attribute *most_aim_def_attrs[] = {
&most_aim_attr_add_link.attr,
&most_aim_attr_remove_link.attr,
NULL,
};
static struct kobj_type most_aim_ktype = {
.sysfs_ops = &most_aim_sysfs_ops,
.release = most_aim_release,
.default_attrs = most_aim_def_attrs,
};
static struct kset *most_aim_kset;
/**
* create_most_aim_obj - creates an AIM object
* @name: name of the AIM
*
* This creates an AIM object assigns the proper kset and registers
* it with sysfs.
* Returns a pointer to the object or NULL if something went wrong.
*/
static struct most_aim_obj *create_most_aim_obj(const char *name)
{
struct most_aim_obj *most_aim;
int retval;
most_aim = kzalloc(sizeof(*most_aim), GFP_KERNEL);
if (!most_aim)
return NULL;
most_aim->kobj.kset = most_aim_kset;
retval = kobject_init_and_add(&most_aim->kobj, &most_aim_ktype,
NULL, "%s", name);
if (retval) {
kobject_put(&most_aim->kobj);
return NULL;
}
kobject_uevent(&most_aim->kobj, KOBJ_ADD);
return most_aim;
}
/**
* destroy_most_aim_obj - AIM release function
* @p: pointer to AIM object
*
* This decrements the reference counter of the AIM object. If the
* reference count turns zero, its release function will be called.
*/
static void destroy_most_aim_obj(struct most_aim_obj *p)
{
kobject_put(&p->kobj);
}
/* ___ ___
* ___C O R E___
*/
/**
* Instantiation of the MOST bus
*/
static struct bus_type most_bus = {
.name = "most",
};
/**
* Instantiation of the core driver
*/
static struct device_driver mostcore = {
.name = "mostcore",
.bus = &most_bus,
};
static inline void trash_mbo(struct mbo *mbo)
{
unsigned long flags;
struct most_c_obj *c = mbo->context;
spin_lock_irqsave(&c->fifo_lock, flags);
list_add(&mbo->list, &c->trash_fifo);
spin_unlock_irqrestore(&c->fifo_lock, flags);
}
static struct mbo *get_hdm_mbo(struct most_c_obj *c)
{
unsigned long flags;
struct mbo *mbo;
spin_lock_irqsave(&c->fifo_lock, flags);
if (c->enqueue_halt || list_empty(&c->halt_fifo))
mbo = NULL;
else
mbo = list_pop_mbo(&c->halt_fifo);
spin_unlock_irqrestore(&c->fifo_lock, flags);
return mbo;
}
static void nq_hdm_mbo(struct mbo *mbo)
{
unsigned long flags;
struct most_c_obj *c = mbo->context;
spin_lock_irqsave(&c->fifo_lock, flags);
list_add_tail(&mbo->list, &c->halt_fifo);
spin_unlock_irqrestore(&c->fifo_lock, flags);
wake_up_interruptible(&c->hdm_fifo_wq);
}
static int hdm_enqueue_thread(void *data)
{
struct most_c_obj *c = data;
struct mbo *mbo;
typeof(c->iface->enqueue) enqueue = c->iface->enqueue;
while (likely(!kthread_should_stop())) {
wait_event_interruptible(c->hdm_fifo_wq,
(mbo = get_hdm_mbo(c)) ||
kthread_should_stop());
if (unlikely(!mbo))
continue;
if (c->cfg.direction == MOST_CH_RX)
mbo->buffer_length = c->cfg.buffer_size;
if (unlikely(enqueue(mbo->ifp, mbo->hdm_channel_id, mbo))) {
pr_err("hdm enqueue failed\n");
nq_hdm_mbo(mbo);
c->hdm_enqueue_task = NULL;
return 0;
}
}
return 0;
}
static int run_enqueue_thread(struct most_c_obj *c, int channel_id)
{
struct task_struct *task =
kthread_run(hdm_enqueue_thread, c, "hdm_fifo_%d",
channel_id);
if (IS_ERR(task))
return PTR_ERR(task);
c->hdm_enqueue_task = task;
return 0;
}
/**
* arm_mbo - recycle MBO for further usage
* @mbo: buffer object
*
* This puts an MBO back to the list to have it ready for up coming
* tx transactions.
*
* In case the MBO belongs to a channel that recently has been
* poisoned, the MBO is scheduled to be trashed.
* Calls the completion handler of an attached AIM.
*/
static void arm_mbo(struct mbo *mbo)
{
unsigned long flags;
struct most_c_obj *c;
BUG_ON((!mbo) || (!mbo->context));
c = mbo->context;
if (c->is_poisoned) {
trash_mbo(mbo);
return;
}
spin_lock_irqsave(&c->fifo_lock, flags);
++*mbo->num_buffers_ptr;
list_add_tail(&mbo->list, &c->fifo);
spin_unlock_irqrestore(&c->fifo_lock, flags);
if (c->aim0.refs && c->aim0.ptr->tx_completion)
c->aim0.ptr->tx_completion(c->iface, c->channel_id);
if (c->aim1.refs && c->aim1.ptr->tx_completion)
c->aim1.ptr->tx_completion(c->iface, c->channel_id);
}
/**
* arm_mbo_chain - helper function that arms an MBO chain for the HDM
* @c: pointer to interface channel
* @dir: direction of the channel
* @compl: pointer to completion function
*
* This allocates buffer objects including the containing DMA coherent
* buffer and puts them in the fifo.
* Buffers of Rx channels are put in the kthread fifo, hence immediately
* submitted to the HDM.
*
* Returns the number of allocated and enqueued MBOs.
*/
static int arm_mbo_chain(struct most_c_obj *c, int dir,
void (*compl)(struct mbo *))
{
unsigned int i;
int retval;
struct mbo *mbo;
u32 coherent_buf_size = c->cfg.buffer_size + c->cfg.extra_len;
atomic_set(&c->mbo_nq_level, 0);
for (i = 0; i < c->cfg.num_buffers; i++) {
mbo = kzalloc(sizeof(*mbo), GFP_KERNEL);
if (!mbo) {
pr_info("WARN: Allocation of MBO failed.\n");
retval = i;
goto _exit;
}
mbo->context = c;
mbo->ifp = c->iface;
mbo->hdm_channel_id = c->channel_id;
mbo->virt_address = dma_alloc_coherent(NULL,
coherent_buf_size,
&mbo->bus_address,
GFP_KERNEL);
if (!mbo->virt_address) {
pr_info("WARN: No DMA coherent buffer.\n");
retval = i;
goto _error1;
}
mbo->complete = compl;
mbo->num_buffers_ptr = &dummy_num_buffers;
if (dir == MOST_CH_RX) {
nq_hdm_mbo(mbo);
atomic_inc(&c->mbo_nq_level);
} else {
arm_mbo(mbo);
}
}
return i;
_error1:
kfree(mbo);
_exit:
return retval;
}
/**
* most_submit_mbo - submits an MBO to fifo
* @mbo: pointer to the MBO
*
*/
int most_submit_mbo(struct mbo *mbo)
{
if (unlikely((!mbo) || (!mbo->context))) {
pr_err("Bad MBO or missing channel reference\n");
return -EINVAL;
}
nq_hdm_mbo(mbo);
return 0;
}
EXPORT_SYMBOL_GPL(most_submit_mbo);
/**
* most_write_completion - write completion handler
* @mbo: pointer to MBO
*
* This recycles the MBO for further usage. In case the channel has been
* poisoned, the MBO is scheduled to be trashed.
*/
static void most_write_completion(struct mbo *mbo)
{
struct most_c_obj *c;
BUG_ON((!mbo) || (!mbo->context));
c = mbo->context;
if (mbo->status == MBO_E_INVAL)
pr_info("WARN: Tx MBO status: invalid\n");
if (unlikely(c->is_poisoned || (mbo->status == MBO_E_CLOSE)))
trash_mbo(mbo);
else
arm_mbo(mbo);
}
/**
* get_channel_by_iface - get pointer to channel object
* @iface: pointer to interface instance
* @id: channel ID
*
* This retrieves a pointer to a channel of the given interface and channel ID.
*/
static struct
most_c_obj *get_channel_by_iface(struct most_interface *iface, int id)
{
struct most_inst_obj *i;
if (unlikely(!iface)) {
pr_err("Bad interface\n");
return NULL;
}
if (unlikely((id < 0) || (id >= iface->num_channels))) {
pr_err("Channel index (%d) out of range\n", id);
return NULL;
}
i = iface->priv;
if (unlikely(!i)) {
pr_err("interface is not registered\n");
return NULL;
}
return i->channel[id];
}
int channel_has_mbo(struct most_interface *iface, int id)
{
struct most_c_obj *c = get_channel_by_iface(iface, id);
unsigned long flags;
int empty;
if (unlikely(!c))
return -EINVAL;
spin_lock_irqsave(&c->fifo_lock, flags);
empty = list_empty(&c->fifo);
spin_unlock_irqrestore(&c->fifo_lock, flags);
return !empty;
}
EXPORT_SYMBOL_GPL(channel_has_mbo);
/**
* most_get_mbo - get pointer to an MBO of pool
* @iface: pointer to interface instance
* @id: channel ID
*
* This attempts to get a free buffer out of the channel fifo.
* Returns a pointer to MBO on success or NULL otherwise.
*/
struct mbo *most_get_mbo(struct most_interface *iface, int id,
struct most_aim *aim)
{
struct mbo *mbo;
struct most_c_obj *c;
unsigned long flags;
int *num_buffers_ptr;
c = get_channel_by_iface(iface, id);
if (unlikely(!c))
return NULL;
if (c->aim0.refs && c->aim1.refs &&
((aim == c->aim0.ptr && c->aim0.num_buffers <= 0) ||
(aim == c->aim1.ptr && c->aim1.num_buffers <= 0)))
return NULL;
if (aim == c->aim0.ptr)
num_buffers_ptr = &c->aim0.num_buffers;
else if (aim == c->aim1.ptr)
num_buffers_ptr = &c->aim1.num_buffers;
else
num_buffers_ptr = &dummy_num_buffers;
spin_lock_irqsave(&c->fifo_lock, flags);
if (list_empty(&c->fifo)) {
spin_unlock_irqrestore(&c->fifo_lock, flags);
return NULL;
}
mbo = list_pop_mbo(&c->fifo);
--*num_buffers_ptr;
spin_unlock_irqrestore(&c->fifo_lock, flags);
mbo->num_buffers_ptr = num_buffers_ptr;
mbo->buffer_length = c->cfg.buffer_size;
return mbo;
}
EXPORT_SYMBOL_GPL(most_get_mbo);
/**
* most_put_mbo - return buffer to pool
* @mbo: buffer object
*/
void most_put_mbo(struct mbo *mbo)
{
struct most_c_obj *c = mbo->context;
if (c->cfg.direction == MOST_CH_TX) {
arm_mbo(mbo);
return;
}
nq_hdm_mbo(mbo);
atomic_inc(&c->mbo_nq_level);
}
EXPORT_SYMBOL_GPL(most_put_mbo);
/**
* most_read_completion - read completion handler
* @mbo: pointer to MBO
*
* This function is called by the HDM when data has been received from the
* hardware and copied to the buffer of the MBO.
*
* In case the channel has been poisoned it puts the buffer in the trash queue.
* Otherwise, it passes the buffer to an AIM for further processing.
*/
static void most_read_completion(struct mbo *mbo)
{
struct most_c_obj *c = mbo->context;
if (unlikely(c->is_poisoned || (mbo->status == MBO_E_CLOSE))) {
trash_mbo(mbo);
return;
}
if (mbo->status == MBO_E_INVAL) {
nq_hdm_mbo(mbo);
atomic_inc(&c->mbo_nq_level);
return;
}
if (atomic_sub_and_test(1, &c->mbo_nq_level)) {
pr_info("WARN: rx device out of buffers\n");
c->is_starving = 1;
}
if (c->aim0.refs && c->aim0.ptr->rx_completion &&
c->aim0.ptr->rx_completion(mbo) == 0)
return;
if (c->aim1.refs && c->aim1.ptr->rx_completion &&
c->aim1.ptr->rx_completion(mbo) == 0)
return;
most_put_mbo(mbo);
}
/**
* most_start_channel - prepares a channel for communication
* @iface: pointer to interface instance
* @id: channel ID
*
* This prepares the channel for usage. Cross-checks whether the
* channel's been properly configured.
*
* Returns 0 on success or error code otherwise.
*/
int most_start_channel(struct most_interface *iface, int id,
struct most_aim *aim)
{
int num_buffer;
int ret;
struct most_c_obj *c = get_channel_by_iface(iface, id);
if (unlikely(!c))
return -EINVAL;
mutex_lock(&c->start_mutex);
if (c->aim0.refs + c->aim1.refs > 0)
goto out; /* already started by other aim */
if (!try_module_get(iface->mod)) {
pr_info("failed to acquire HDM lock\n");
mutex_unlock(&c->start_mutex);
return -ENOLCK;
}
c->cfg.extra_len = 0;
if (c->iface->configure(c->iface, c->channel_id, &c->cfg)) {
pr_info("channel configuration failed. Go check settings...\n");
ret = -EINVAL;
goto error;
}
init_waitqueue_head(&c->hdm_fifo_wq);
if (c->cfg.direction == MOST_CH_RX)
num_buffer = arm_mbo_chain(c, c->cfg.direction,
most_read_completion);
else
num_buffer = arm_mbo_chain(c, c->cfg.direction,
most_write_completion);
if (unlikely(!num_buffer)) {
pr_info("failed to allocate memory\n");
ret = -ENOMEM;
goto error;
}
ret = run_enqueue_thread(c, id);
if (ret)
goto error;
c->is_starving = 0;
c->aim0.num_buffers = c->cfg.num_buffers / 2;
c->aim1.num_buffers = c->cfg.num_buffers - c->aim0.num_buffers;
atomic_set(&c->mbo_ref, num_buffer);
out:
if (aim == c->aim0.ptr)
c->aim0.refs++;
if (aim == c->aim1.ptr)
c->aim1.refs++;
mutex_unlock(&c->start_mutex);
return 0;
error:
module_put(iface->mod);
mutex_unlock(&c->start_mutex);
return ret;
}
EXPORT_SYMBOL_GPL(most_start_channel);
/**
* most_stop_channel - stops a running channel
* @iface: pointer to interface instance
* @id: channel ID
*/
int most_stop_channel(struct most_interface *iface, int id,
struct most_aim *aim)
{
struct most_c_obj *c;
if (unlikely((!iface) || (id >= iface->num_channels) || (id < 0))) {
pr_err("Bad interface or index out of range\n");
return -EINVAL;
}
c = get_channel_by_iface(iface, id);
if (unlikely(!c))
return -EINVAL;
mutex_lock(&c->start_mutex);
if (c->aim0.refs + c->aim1.refs >= 2)
goto out;
mutex_lock(&c->stop_task_mutex);
if (c->hdm_enqueue_task)
kthread_stop(c->hdm_enqueue_task);
c->hdm_enqueue_task = NULL;
mutex_unlock(&c->stop_task_mutex);
if (iface->mod)
module_put(iface->mod);
c->is_poisoned = true;
if (c->iface->poison_channel(c->iface, c->channel_id)) {
pr_err("Cannot stop channel %d of mdev %s\n", c->channel_id,
c->iface->description);
mutex_unlock(&c->start_mutex);
return -EAGAIN;
}
flush_trash_fifo(c);
flush_channel_fifos(c);
#ifdef CMPL_INTERRUPTIBLE
if (wait_for_completion_interruptible(&c->cleanup)) {
pr_info("Interrupted while clean up ch %d\n", c->channel_id);
mutex_unlock(&c->start_mutex);
return -EINTR;
}
#else
wait_for_completion(&c->cleanup);
#endif
c->is_poisoned = false;
out:
if (aim == c->aim0.ptr)
c->aim0.refs--;
if (aim == c->aim1.ptr)
c->aim1.refs--;
mutex_unlock(&c->start_mutex);
return 0;
}
EXPORT_SYMBOL_GPL(most_stop_channel);
/**
* most_register_aim - registers an AIM (driver) with the core
* @aim: instance of AIM to be registered
*/
int most_register_aim(struct most_aim *aim)
{
struct most_aim_obj *aim_obj;
if (!aim) {
pr_err("Bad driver\n");
return -EINVAL;
}
aim_obj = create_most_aim_obj(aim->name);
if (!aim_obj) {
pr_info("failed to alloc driver object\n");
return -ENOMEM;
}
aim_obj->driver = aim;
aim->context = aim_obj;
pr_info("registered new application interfacing module %s\n",
aim->name);
list_add_tail(&aim_obj->list, &aim_list);
return 0;
}
EXPORT_SYMBOL_GPL(most_register_aim);
/**
* most_deregister_aim - deregisters an AIM (driver) with the core
* @aim: AIM to be removed
*/
int most_deregister_aim(struct most_aim *aim)
{
struct most_aim_obj *aim_obj;
struct most_c_obj *c, *tmp;
struct most_inst_obj *i, *i_tmp;
if (!aim) {
pr_err("Bad driver\n");
return -EINVAL;
}
aim_obj = aim->context;
if (!aim_obj) {
pr_info("driver not registered.\n");
return -EINVAL;
}
list_for_each_entry_safe(i, i_tmp, &instance_list, list) {
list_for_each_entry_safe(c, tmp, &i->channel_list, list) {
if (c->aim0.ptr == aim || c->aim1.ptr == aim)
aim->disconnect_channel(
c->iface, c->channel_id);
if (c->aim0.ptr == aim)
c->aim0.ptr = NULL;
if (c->aim1.ptr == aim)
c->aim1.ptr = NULL;
}
}
list_del(&aim_obj->list);
destroy_most_aim_obj(aim_obj);
pr_info("deregistering application interfacing module %s\n", aim->name);
return 0;
}
EXPORT_SYMBOL_GPL(most_deregister_aim);
/**
* most_register_interface - registers an interface with core
* @iface: pointer to the instance of the interface description.
*
* Allocates and initializes a new interface instance and all of its channels.
* Returns a pointer to kobject or an error pointer.
*/
struct kobject *most_register_interface(struct most_interface *iface)
{
unsigned int i;
int id;
char name[STRING_SIZE];
char channel_name[STRING_SIZE];
struct most_c_obj *c;
struct most_inst_obj *inst;
if (!iface || !iface->enqueue || !iface->configure ||
!iface->poison_channel || (iface->num_channels > MAX_CHANNELS)) {
pr_err("Bad interface or channel overflow\n");
return ERR_PTR(-EINVAL);
}
id = ida_simple_get(&mdev_id, 0, 0, GFP_KERNEL);
if (id < 0) {
pr_info("Failed to alloc mdev ID\n");
return ERR_PTR(id);
}
snprintf(name, STRING_SIZE, "mdev%d", id);
inst = create_most_inst_obj(name);
if (!inst) {
pr_info("Failed to allocate interface instance\n");
ida_simple_remove(&mdev_id, id);
return ERR_PTR(-ENOMEM);
}
iface->priv = inst;
INIT_LIST_HEAD(&inst->channel_list);
inst->iface = iface;
inst->dev_id = id;
list_add_tail(&inst->list, &instance_list);
for (i = 0; i < iface->num_channels; i++) {
const char *name_suffix = iface->channel_vector[i].name_suffix;
if (!name_suffix)
snprintf(channel_name, STRING_SIZE, "ch%d", i);
else if (name_suffix[0] == '@')
snprintf(channel_name, STRING_SIZE, "ch%d%s", i,
name_suffix);
else
snprintf(channel_name, STRING_SIZE, "%s", name_suffix);
/* this increments the reference count of this instance */
c = create_most_c_obj(channel_name, &inst->kobj);
if (!c)
goto free_instance;
inst->channel[i] = c;
c->is_starving = 0;
c->iface = iface;
c->inst = inst;
c->channel_id = i;
c->keep_mbo = false;
c->enqueue_halt = false;
c->is_poisoned = false;
c->cfg.direction = 0;
c->cfg.data_type = 0;
c->cfg.num_buffers = 0;
c->cfg.buffer_size = 0;
c->cfg.subbuffer_size = 0;
c->cfg.packets_per_xact = 0;
spin_lock_init(&c->fifo_lock);
INIT_LIST_HEAD(&c->fifo);
INIT_LIST_HEAD(&c->trash_fifo);
INIT_LIST_HEAD(&c->halt_fifo);
init_completion(&c->cleanup);
atomic_set(&c->mbo_ref, 0);
mutex_init(&c->start_mutex);
mutex_init(&c->stop_task_mutex);
list_add_tail(&c->list, &inst->channel_list);
}
pr_info("registered new MOST device mdev%d (%s)\n",
inst->dev_id, iface->description);
return &inst->kobj;
free_instance:
pr_info("Failed allocate channel(s)\n");
list_del(&inst->list);
ida_simple_remove(&mdev_id, id);
destroy_most_inst_obj(inst);
return ERR_PTR(-ENOMEM);
}
EXPORT_SYMBOL_GPL(most_register_interface);
/**
* most_deregister_interface - deregisters an interface with core
* @iface: pointer to the interface instance description.
*
* Before removing an interface instance from the list, all running
* channels are stopped and poisoned.
*/
void most_deregister_interface(struct most_interface *iface)
{
struct most_inst_obj *i = iface->priv;
struct most_c_obj *c;
if (unlikely(!i)) {
pr_info("Bad Interface\n");
return;
}
pr_info("deregistering MOST device %s (%s)\n", i->kobj.name,
iface->description);
list_for_each_entry(c, &i->channel_list, list) {
if (c->aim0.ptr)
c->aim0.ptr->disconnect_channel(c->iface,
c->channel_id);
if (c->aim1.ptr)
c->aim1.ptr->disconnect_channel(c->iface,
c->channel_id);
c->aim0.ptr = NULL;
c->aim1.ptr = NULL;
}
list_for_each_entry(c, &i->channel_list, list) {
if (c->aim0.refs + c->aim1.refs <= 0)
continue;
mutex_lock(&c->stop_task_mutex);
if (c->hdm_enqueue_task)
kthread_stop(c->hdm_enqueue_task);
c->hdm_enqueue_task = NULL;
mutex_unlock(&c->stop_task_mutex);
if (iface->poison_channel(iface, c->channel_id))
pr_err("Can't poison channel %d\n", c->channel_id);
}
ida_simple_remove(&mdev_id, i->dev_id);
list_del(&i->list);
destroy_most_inst_obj(i);
}
EXPORT_SYMBOL_GPL(most_deregister_interface);
/**
* most_stop_enqueue - prevents core from enqueueing MBOs
* @iface: pointer to interface
* @id: channel id
*
* This is called by an HDM that _cannot_ attend to its duties and
* is imminent to get run over by the core. The core is not going to
* enqueue any further packets unless the flagging HDM calls
* most_resume enqueue().
*/
void most_stop_enqueue(struct most_interface *iface, int id)
{
struct most_c_obj *c = get_channel_by_iface(iface, id);
if (likely(c))
c->enqueue_halt = true;
}
EXPORT_SYMBOL_GPL(most_stop_enqueue);
/**
* most_resume_enqueue - allow core to enqueue MBOs again
* @iface: pointer to interface
* @id: channel id
*
* This clears the enqueue halt flag and enqueues all MBOs currently
* sitting in the wait fifo.
*/
void most_resume_enqueue(struct most_interface *iface, int id)
{
struct most_c_obj *c = get_channel_by_iface(iface, id);
if (unlikely(!c))
return;
c->enqueue_halt = false;
wake_up_interruptible(&c->hdm_fifo_wq);
}
EXPORT_SYMBOL_GPL(most_resume_enqueue);
static int __init most_init(void)
{
pr_info("init()\n");
INIT_LIST_HEAD(&instance_list);
INIT_LIST_HEAD(&aim_list);
mutex_init(&deregister_mutex);
ida_init(&mdev_id);
if (bus_register(&most_bus)) {
pr_info("Cannot register most bus\n");
goto exit;
}
most_class = class_create(THIS_MODULE, "most");
if (IS_ERR(most_class)) {
pr_info("No udev support.\n");
goto exit_bus;
}
if (driver_register(&mostcore)) {
pr_info("Cannot register core driver\n");
goto exit_class;
}
class_glue_dir =
device_create(most_class, NULL, 0, NULL, "mostcore");
if (!class_glue_dir)
goto exit_driver;
most_aim_kset =
kset_create_and_add("aims", NULL, &class_glue_dir->kobj);
if (!most_aim_kset)
goto exit_class_container;
most_inst_kset =
kset_create_and_add("devices", NULL, &class_glue_dir->kobj);
if (!most_inst_kset)
goto exit_driver_kset;
return 0;
exit_driver_kset:
kset_unregister(most_aim_kset);
exit_class_container:
device_destroy(most_class, 0);
exit_driver:
driver_unregister(&mostcore);
exit_class:
class_destroy(most_class);
exit_bus:
bus_unregister(&most_bus);
exit:
return -ENOMEM;
}
static void __exit most_exit(void)
{
struct most_inst_obj *i, *i_tmp;
struct most_aim_obj *d, *d_tmp;
pr_info("exit core module\n");
list_for_each_entry_safe(d, d_tmp, &aim_list, list) {
destroy_most_aim_obj(d);
}
list_for_each_entry_safe(i, i_tmp, &instance_list, list) {
list_del(&i->list);
destroy_most_inst_obj(i);
}
kset_unregister(most_inst_kset);
kset_unregister(most_aim_kset);
device_destroy(most_class, 0);
driver_unregister(&mostcore);
class_destroy(most_class);
bus_unregister(&most_bus);
ida_destroy(&mdev_id);
}
module_init(most_init);
module_exit(most_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Christian Gromm <christian.gromm@microchip.com>");
MODULE_DESCRIPTION("Core module of stacked MOST Linux driver");
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