diff options
Diffstat (limited to 'driver/mostcore/core.c')
| -rw-r--r-- | driver/mostcore/core.c | 1961 |
1 files changed, 1961 insertions, 0 deletions
diff --git a/driver/mostcore/core.c b/driver/mostcore/core.c new file mode 100644 index 0000000..81dbac9 --- /dev/null +++ b/driver/mostcore/core.c @@ -0,0 +1,1961 @@ +/* + * 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 *core_dev; +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; + struct mutex nq_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; + 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; +}; + +static const struct { + int most_ch_data_type; + char *name; +} ch_data_type[] = { { MOST_CH_CONTROL, "control\n" }, + { MOST_CH_ASYNC, "async\n" }, + { MOST_CH_SYNC, "sync\n" }, + { MOST_CH_ISOC_AVP, "isoc_avp\n"} }; + +#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; \ +}) + +/* ___ ___ + * ___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) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(ch_data_type); i++) { + if (c->cfg.data_type & ch_data_type[i].most_ch_data_type) + return snprintf(buf, PAGE_SIZE, ch_data_type[i].name); + } + 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) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(ch_data_type); i++) { + if (!strcmp(buf, ch_data_type[i].name)) { + c->cfg.data_type = ch_data_type[i].most_ch_data_type; + break; + } + } + + if (i == ARRAY_SIZE(ch_data_type)) { + 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) { + flush_trash_fifo(c); + flush_channel_fifos(c); + 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 bool hdm_mbo_ready(struct most_c_obj *c) +{ + bool empty; + + if (c->enqueue_halt) + return false; + + spin_lock_irq(&c->fifo_lock); + empty = list_empty(&c->halt_fifo); + spin_unlock_irq(&c->fifo_lock); + + return !empty; +} + +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; + int ret; + typeof(c->iface->enqueue) enqueue = c->iface->enqueue; + + while (likely(!kthread_should_stop())) { + wait_event_interruptible(c->hdm_fifo_wq, + hdm_mbo_ready(c) || + kthread_should_stop()); + + mutex_lock(&c->nq_mutex); + spin_lock_irq(&c->fifo_lock); + if (unlikely(c->enqueue_halt || list_empty(&c->halt_fifo))) { + spin_unlock_irq(&c->fifo_lock); + mutex_unlock(&c->nq_mutex); + continue; + } + + mbo = list_pop_mbo(&c->halt_fifo); + spin_unlock_irq(&c->fifo_lock); + + if (c->cfg.direction == MOST_CH_RX) + mbo->buffer_length = c->cfg.buffer_size; + + ret = enqueue(mbo->ifp, mbo->hdm_channel_id, mbo); + mutex_unlock(&c->nq_mutex); + + if (unlikely(ret)) { + 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) { + 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_aim *aim) +{ + struct most_c_obj *c = get_channel_by_iface(iface, id); + unsigned long flags; + int empty; + + if (unlikely(!c)) + return -EINVAL; + + 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 0; + + 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)) + 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; + + if (c->hdm_enqueue_task) + kthread_stop(c->hdm_enqueue_task); + c->hdm_enqueue_task = NULL; + + 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->nq_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; + } + + 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 (!c) + return; + + mutex_lock(&c->nq_mutex); + c->enqueue_halt = true; + mutex_unlock(&c->nq_mutex); +} +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 (!c) + return; + + mutex_lock(&c->nq_mutex); + c->enqueue_halt = false; + mutex_unlock(&c->nq_mutex); + + wake_up_interruptible(&c->hdm_fifo_wq); +} +EXPORT_SYMBOL_GPL(most_resume_enqueue); + +static int __init most_init(void) +{ + int err; + + pr_info("init()\n"); + INIT_LIST_HEAD(&instance_list); + INIT_LIST_HEAD(&aim_list); + ida_init(&mdev_id); + + err = bus_register(&most_bus); + if (err) { + pr_info("Cannot register most bus\n"); + return err; + } + + most_class = class_create(THIS_MODULE, "most"); + if (IS_ERR(most_class)) { + pr_info("No udev support.\n"); + err = PTR_ERR(most_class); + goto exit_bus; + } + + err = driver_register(&mostcore); + if (err) { + pr_info("Cannot register core driver\n"); + goto exit_class; + } + + core_dev = device_create(most_class, NULL, 0, NULL, "mostcore"); + if (IS_ERR(core_dev)) { + err = PTR_ERR(core_dev); + goto exit_driver; + } + + most_aim_kset = kset_create_and_add("aims", NULL, &core_dev->kobj); + if (!most_aim_kset) { + err = -ENOMEM; + goto exit_class_container; + } + + most_inst_kset = kset_create_and_add("devices", NULL, &core_dev->kobj); + if (!most_inst_kset) { + err = -ENOMEM; + 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); + return err; +} + +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"); |