diff options
Diffstat (limited to '')
| -rw-r--r-- | arch/um/drivers/chan_kern.c | 570 |
1 files changed, 570 insertions, 0 deletions
diff --git a/arch/um/drivers/chan_kern.c b/arch/um/drivers/chan_kern.c new file mode 100644 index 000000000..62997055c --- /dev/null +++ b/arch/um/drivers/chan_kern.c @@ -0,0 +1,570 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{linux.intel,addtoit}.com) + */ + +#include <linux/slab.h> +#include <linux/tty.h> +#include <linux/tty_flip.h> +#include "chan.h" +#include <os.h> +#include <irq_kern.h> + +#ifdef CONFIG_NOCONFIG_CHAN +static void *not_configged_init(char *str, int device, + const struct chan_opts *opts) +{ + printk(KERN_ERR "Using a channel type which is configured out of " + "UML\n"); + return NULL; +} + +static int not_configged_open(int input, int output, int primary, void *data, + char **dev_out) +{ + printk(KERN_ERR "Using a channel type which is configured out of " + "UML\n"); + return -ENODEV; +} + +static void not_configged_close(int fd, void *data) +{ + printk(KERN_ERR "Using a channel type which is configured out of " + "UML\n"); +} + +static int not_configged_read(int fd, char *c_out, void *data) +{ + printk(KERN_ERR "Using a channel type which is configured out of " + "UML\n"); + return -EIO; +} + +static int not_configged_write(int fd, const char *buf, int len, void *data) +{ + printk(KERN_ERR "Using a channel type which is configured out of " + "UML\n"); + return -EIO; +} + +static int not_configged_console_write(int fd, const char *buf, int len) +{ + printk(KERN_ERR "Using a channel type which is configured out of " + "UML\n"); + return -EIO; +} + +static int not_configged_window_size(int fd, void *data, unsigned short *rows, + unsigned short *cols) +{ + printk(KERN_ERR "Using a channel type which is configured out of " + "UML\n"); + return -ENODEV; +} + +static void not_configged_free(void *data) +{ + printk(KERN_ERR "Using a channel type which is configured out of " + "UML\n"); +} + +static const struct chan_ops not_configged_ops = { + .init = not_configged_init, + .open = not_configged_open, + .close = not_configged_close, + .read = not_configged_read, + .write = not_configged_write, + .console_write = not_configged_console_write, + .window_size = not_configged_window_size, + .free = not_configged_free, + .winch = 0, +}; +#endif /* CONFIG_NOCONFIG_CHAN */ + +static int open_one_chan(struct chan *chan) +{ + int fd, err; + + if (chan->opened) + return 0; + + if (chan->ops->open == NULL) + fd = 0; + else fd = (*chan->ops->open)(chan->input, chan->output, chan->primary, + chan->data, &chan->dev); + if (fd < 0) + return fd; + + err = os_set_fd_block(fd, 0); + if (err) { + (*chan->ops->close)(fd, chan->data); + return err; + } + + chan->fd = fd; + + chan->opened = 1; + return 0; +} + +static int open_chan(struct list_head *chans) +{ + struct list_head *ele; + struct chan *chan; + int ret, err = 0; + + list_for_each(ele, chans) { + chan = list_entry(ele, struct chan, list); + ret = open_one_chan(chan); + if (chan->primary) + err = ret; + } + return err; +} + +void chan_enable_winch(struct chan *chan, struct tty_port *port) +{ + if (chan && chan->primary && chan->ops->winch) + register_winch(chan->fd, port); +} + +static void line_timer_cb(struct work_struct *work) +{ + struct line *line = container_of(work, struct line, task.work); + + if (!line->throttled) + chan_interrupt(line, line->driver->read_irq); +} + +int enable_chan(struct line *line) +{ + struct list_head *ele; + struct chan *chan; + int err; + + INIT_DELAYED_WORK(&line->task, line_timer_cb); + + list_for_each(ele, &line->chan_list) { + chan = list_entry(ele, struct chan, list); + err = open_one_chan(chan); + if (err) { + if (chan->primary) + goto out_close; + + continue; + } + + if (chan->enabled) + continue; + err = line_setup_irq(chan->fd, chan->input, chan->output, line, + chan); + if (err) + goto out_close; + + chan->enabled = 1; + } + + return 0; + + out_close: + close_chan(line); + return err; +} + +/* Items are added in IRQ context, when free_irq can't be called, and + * removed in process context, when it can. + * This handles interrupt sources which disappear, and which need to + * be permanently disabled. This is discovered in IRQ context, but + * the freeing of the IRQ must be done later. + */ +static DEFINE_SPINLOCK(irqs_to_free_lock); +static LIST_HEAD(irqs_to_free); + +void free_irqs(void) +{ + struct chan *chan; + LIST_HEAD(list); + struct list_head *ele; + unsigned long flags; + + spin_lock_irqsave(&irqs_to_free_lock, flags); + list_splice_init(&irqs_to_free, &list); + spin_unlock_irqrestore(&irqs_to_free_lock, flags); + + list_for_each(ele, &list) { + chan = list_entry(ele, struct chan, free_list); + + if (chan->input && chan->enabled) + um_free_irq(chan->line->driver->read_irq, chan); + if (chan->output && chan->enabled) + um_free_irq(chan->line->driver->write_irq, chan); + chan->enabled = 0; + } +} + +static void close_one_chan(struct chan *chan, int delay_free_irq) +{ + unsigned long flags; + + if (!chan->opened) + return; + + if (delay_free_irq) { + spin_lock_irqsave(&irqs_to_free_lock, flags); + list_add(&chan->free_list, &irqs_to_free); + spin_unlock_irqrestore(&irqs_to_free_lock, flags); + } else { + if (chan->input && chan->enabled) + um_free_irq(chan->line->driver->read_irq, chan); + if (chan->output && chan->enabled) + um_free_irq(chan->line->driver->write_irq, chan); + chan->enabled = 0; + } + if (chan->ops->close != NULL) + (*chan->ops->close)(chan->fd, chan->data); + + chan->opened = 0; + chan->fd = -1; +} + +void close_chan(struct line *line) +{ + struct chan *chan; + + /* Close in reverse order as open in case more than one of them + * refers to the same device and they save and restore that device's + * state. Then, the first one opened will have the original state, + * so it must be the last closed. + */ + list_for_each_entry_reverse(chan, &line->chan_list, list) { + close_one_chan(chan, 0); + } +} + +void deactivate_chan(struct chan *chan, int irq) +{ + if (chan && chan->enabled) + deactivate_fd(chan->fd, irq); +} + +int write_chan(struct chan *chan, const char *buf, int len, + int write_irq) +{ + int n, ret = 0; + + if (len == 0 || !chan || !chan->ops->write) + return 0; + + n = chan->ops->write(chan->fd, buf, len, chan->data); + if (chan->primary) { + ret = n; + } + return ret; +} + +int console_write_chan(struct chan *chan, const char *buf, int len) +{ + int n, ret = 0; + + if (!chan || !chan->ops->console_write) + return 0; + + n = chan->ops->console_write(chan->fd, buf, len); + if (chan->primary) + ret = n; + return ret; +} + +int console_open_chan(struct line *line, struct console *co) +{ + int err; + + err = open_chan(&line->chan_list); + if (err) + return err; + + printk(KERN_INFO "Console initialized on /dev/%s%d\n", co->name, + co->index); + return 0; +} + +int chan_window_size(struct line *line, unsigned short *rows_out, + unsigned short *cols_out) +{ + struct chan *chan; + + chan = line->chan_in; + if (chan && chan->primary) { + if (chan->ops->window_size == NULL) + return 0; + return chan->ops->window_size(chan->fd, chan->data, + rows_out, cols_out); + } + chan = line->chan_out; + if (chan && chan->primary) { + if (chan->ops->window_size == NULL) + return 0; + return chan->ops->window_size(chan->fd, chan->data, + rows_out, cols_out); + } + return 0; +} + +static void free_one_chan(struct chan *chan) +{ + list_del(&chan->list); + + close_one_chan(chan, 0); + + if (chan->ops->free != NULL) + (*chan->ops->free)(chan->data); + + if (chan->primary && chan->output) + ignore_sigio_fd(chan->fd); + kfree(chan); +} + +static void free_chan(struct list_head *chans) +{ + struct list_head *ele, *next; + struct chan *chan; + + list_for_each_safe(ele, next, chans) { + chan = list_entry(ele, struct chan, list); + free_one_chan(chan); + } +} + +static int one_chan_config_string(struct chan *chan, char *str, int size, + char **error_out) +{ + int n = 0; + + if (chan == NULL) { + CONFIG_CHUNK(str, size, n, "none", 1); + return n; + } + + CONFIG_CHUNK(str, size, n, chan->ops->type, 0); + + if (chan->dev == NULL) { + CONFIG_CHUNK(str, size, n, "", 1); + return n; + } + + CONFIG_CHUNK(str, size, n, ":", 0); + CONFIG_CHUNK(str, size, n, chan->dev, 0); + + return n; +} + +static int chan_pair_config_string(struct chan *in, struct chan *out, + char *str, int size, char **error_out) +{ + int n; + + n = one_chan_config_string(in, str, size, error_out); + str += n; + size -= n; + + if (in == out) { + CONFIG_CHUNK(str, size, n, "", 1); + return n; + } + + CONFIG_CHUNK(str, size, n, ",", 1); + n = one_chan_config_string(out, str, size, error_out); + str += n; + size -= n; + CONFIG_CHUNK(str, size, n, "", 1); + + return n; +} + +int chan_config_string(struct line *line, char *str, int size, + char **error_out) +{ + struct chan *in = line->chan_in, *out = line->chan_out; + + if (in && !in->primary) + in = NULL; + if (out && !out->primary) + out = NULL; + + return chan_pair_config_string(in, out, str, size, error_out); +} + +struct chan_type { + char *key; + const struct chan_ops *ops; +}; + +static const struct chan_type chan_table[] = { + { "fd", &fd_ops }, + +#ifdef CONFIG_NULL_CHAN + { "null", &null_ops }, +#else + { "null", ¬_configged_ops }, +#endif + +#ifdef CONFIG_PORT_CHAN + { "port", &port_ops }, +#else + { "port", ¬_configged_ops }, +#endif + +#ifdef CONFIG_PTY_CHAN + { "pty", &pty_ops }, + { "pts", &pts_ops }, +#else + { "pty", ¬_configged_ops }, + { "pts", ¬_configged_ops }, +#endif + +#ifdef CONFIG_TTY_CHAN + { "tty", &tty_ops }, +#else + { "tty", ¬_configged_ops }, +#endif + +#ifdef CONFIG_XTERM_CHAN + { "xterm", &xterm_ops }, +#else + { "xterm", ¬_configged_ops }, +#endif +}; + +static struct chan *parse_chan(struct line *line, char *str, int device, + const struct chan_opts *opts, char **error_out) +{ + const struct chan_type *entry; + const struct chan_ops *ops; + struct chan *chan; + void *data; + int i; + + ops = NULL; + data = NULL; + for(i = 0; i < ARRAY_SIZE(chan_table); i++) { + entry = &chan_table[i]; + if (!strncmp(str, entry->key, strlen(entry->key))) { + ops = entry->ops; + str += strlen(entry->key); + break; + } + } + if (ops == NULL) { + *error_out = "No match for configured backends"; + return NULL; + } + + data = (*ops->init)(str, device, opts); + if (data == NULL) { + *error_out = "Configuration failed"; + return NULL; + } + + chan = kmalloc(sizeof(*chan), GFP_ATOMIC); + if (chan == NULL) { + *error_out = "Memory allocation failed"; + return NULL; + } + *chan = ((struct chan) { .list = LIST_HEAD_INIT(chan->list), + .free_list = + LIST_HEAD_INIT(chan->free_list), + .line = line, + .primary = 1, + .input = 0, + .output = 0, + .opened = 0, + .enabled = 0, + .fd = -1, + .ops = ops, + .data = data }); + return chan; +} + +int parse_chan_pair(char *str, struct line *line, int device, + const struct chan_opts *opts, char **error_out) +{ + struct list_head *chans = &line->chan_list; + struct chan *new; + char *in, *out; + + if (!list_empty(chans)) { + line->chan_in = line->chan_out = NULL; + free_chan(chans); + INIT_LIST_HEAD(chans); + } + + if (!str) + return 0; + + out = strchr(str, ','); + if (out != NULL) { + in = str; + *out = '\0'; + out++; + new = parse_chan(line, in, device, opts, error_out); + if (new == NULL) + return -1; + + new->input = 1; + list_add(&new->list, chans); + line->chan_in = new; + + new = parse_chan(line, out, device, opts, error_out); + if (new == NULL) + return -1; + + list_add(&new->list, chans); + new->output = 1; + line->chan_out = new; + } + else { + new = parse_chan(line, str, device, opts, error_out); + if (new == NULL) + return -1; + + list_add(&new->list, chans); + new->input = 1; + new->output = 1; + line->chan_in = line->chan_out = new; + } + return 0; +} + +void chan_interrupt(struct line *line, int irq) +{ + struct tty_port *port = &line->port; + struct chan *chan = line->chan_in; + int err; + char c; + + if (!chan || !chan->ops->read) + goto out; + + do { + if (!tty_buffer_request_room(port, 1)) { + schedule_delayed_work(&line->task, 1); + goto out; + } + err = chan->ops->read(chan->fd, &c, chan->data); + if (err > 0) + tty_insert_flip_char(port, c, TTY_NORMAL); + } while (err > 0); + + if (err == -EIO) { + if (chan->primary) { + tty_port_tty_hangup(&line->port, false); + if (line->chan_out != chan) + close_one_chan(line->chan_out, 1); + } + close_one_chan(chan, 1); + if (chan->primary) + return; + } + out: + tty_flip_buffer_push(port); +} |