diff options
Diffstat (limited to 'drivers/input/input.c')
-rw-r--r-- | drivers/input/input.c | 228 |
1 files changed, 181 insertions, 47 deletions
diff --git a/drivers/input/input.c b/drivers/input/input.c index 16ec33f27c5d..30b503b8d67b 100644 --- a/drivers/input/input.c +++ b/drivers/input/input.c @@ -17,12 +17,14 @@ #include <linux/random.h> #include <linux/major.h> #include <linux/proc_fs.h> +#include <linux/sched.h> #include <linux/seq_file.h> #include <linux/poll.h> #include <linux/device.h> #include <linux/mutex.h> #include <linux/rcupdate.h> #include <linux/smp_lock.h> +#include "input-compat.h" MODULE_AUTHOR("Vojtech Pavlik <vojtech@suse.cz>"); MODULE_DESCRIPTION("Input core"); @@ -295,9 +297,15 @@ static void input_handle_event(struct input_dev *dev, * @value: value of the event * * This function should be used by drivers implementing various input - * devices. See also input_inject_event(). + * devices to report input events. See also input_inject_event(). + * + * NOTE: input_event() may be safely used right after input device was + * allocated with input_allocate_device(), even before it is registered + * with input_register_device(), but the event will not reach any of the + * input handlers. Such early invocation of input_event() may be used + * to 'seed' initial state of a switch or initial position of absolute + * axis, etc. */ - void input_event(struct input_dev *dev, unsigned int type, unsigned int code, int value) { @@ -757,6 +765,40 @@ static int input_attach_handler(struct input_dev *dev, struct input_handler *han return error; } +#ifdef CONFIG_COMPAT + +static int input_bits_to_string(char *buf, int buf_size, + unsigned long bits, bool skip_empty) +{ + int len = 0; + + if (INPUT_COMPAT_TEST) { + u32 dword = bits >> 32; + if (dword || !skip_empty) + len += snprintf(buf, buf_size, "%x ", dword); + + dword = bits & 0xffffffffUL; + if (dword || !skip_empty || len) + len += snprintf(buf + len, max(buf_size - len, 0), + "%x", dword); + } else { + if (bits || !skip_empty) + len += snprintf(buf, buf_size, "%lx", bits); + } + + return len; +} + +#else /* !CONFIG_COMPAT */ + +static int input_bits_to_string(char *buf, int buf_size, + unsigned long bits, bool skip_empty) +{ + return bits || !skip_empty ? + snprintf(buf, buf_size, "%lx", bits) : 0; +} + +#endif #ifdef CONFIG_PROC_FS @@ -781,10 +823,29 @@ static unsigned int input_proc_devices_poll(struct file *file, poll_table *wait) return 0; } +union input_seq_state { + struct { + unsigned short pos; + bool mutex_acquired; + }; + void *p; +}; + static void *input_devices_seq_start(struct seq_file *seq, loff_t *pos) { - if (mutex_lock_interruptible(&input_mutex)) - return NULL; + union input_seq_state *state = (union input_seq_state *)&seq->private; + int error; + + /* We need to fit into seq->private pointer */ + BUILD_BUG_ON(sizeof(union input_seq_state) != sizeof(seq->private)); + + error = mutex_lock_interruptible(&input_mutex); + if (error) { + state->mutex_acquired = false; + return ERR_PTR(error); + } + + state->mutex_acquired = true; return seq_list_start(&input_dev_list, *pos); } @@ -794,23 +855,37 @@ static void *input_devices_seq_next(struct seq_file *seq, void *v, loff_t *pos) return seq_list_next(v, &input_dev_list, pos); } -static void input_devices_seq_stop(struct seq_file *seq, void *v) +static void input_seq_stop(struct seq_file *seq, void *v) { - mutex_unlock(&input_mutex); + union input_seq_state *state = (union input_seq_state *)&seq->private; + + if (state->mutex_acquired) + mutex_unlock(&input_mutex); } static void input_seq_print_bitmap(struct seq_file *seq, const char *name, unsigned long *bitmap, int max) { int i; - - for (i = BITS_TO_LONGS(max) - 1; i > 0; i--) - if (bitmap[i]) - break; + bool skip_empty = true; + char buf[18]; seq_printf(seq, "B: %s=", name); - for (; i >= 0; i--) - seq_printf(seq, "%lx%s", bitmap[i], i > 0 ? " " : ""); + + for (i = BITS_TO_LONGS(max) - 1; i >= 0; i--) { + if (input_bits_to_string(buf, sizeof(buf), + bitmap[i], skip_empty)) { + skip_empty = false; + seq_printf(seq, "%s%s", buf, i > 0 ? " " : ""); + } + } + + /* + * If no output was produced print a single 0. + */ + if (skip_empty) + seq_puts(seq, "0"); + seq_putc(seq, '\n'); } @@ -860,7 +935,7 @@ static int input_devices_seq_show(struct seq_file *seq, void *v) static const struct seq_operations input_devices_seq_ops = { .start = input_devices_seq_start, .next = input_devices_seq_next, - .stop = input_devices_seq_stop, + .stop = input_seq_stop, .show = input_devices_seq_show, }; @@ -880,40 +955,49 @@ static const struct file_operations input_devices_fileops = { static void *input_handlers_seq_start(struct seq_file *seq, loff_t *pos) { - if (mutex_lock_interruptible(&input_mutex)) - return NULL; + union input_seq_state *state = (union input_seq_state *)&seq->private; + int error; + + /* We need to fit into seq->private pointer */ + BUILD_BUG_ON(sizeof(union input_seq_state) != sizeof(seq->private)); + + error = mutex_lock_interruptible(&input_mutex); + if (error) { + state->mutex_acquired = false; + return ERR_PTR(error); + } + + state->mutex_acquired = true; + state->pos = *pos; - seq->private = (void *)(unsigned long)*pos; return seq_list_start(&input_handler_list, *pos); } static void *input_handlers_seq_next(struct seq_file *seq, void *v, loff_t *pos) { - seq->private = (void *)(unsigned long)(*pos + 1); - return seq_list_next(v, &input_handler_list, pos); -} + union input_seq_state *state = (union input_seq_state *)&seq->private; -static void input_handlers_seq_stop(struct seq_file *seq, void *v) -{ - mutex_unlock(&input_mutex); + state->pos = *pos + 1; + return seq_list_next(v, &input_handler_list, pos); } static int input_handlers_seq_show(struct seq_file *seq, void *v) { struct input_handler *handler = container_of(v, struct input_handler, node); + union input_seq_state *state = (union input_seq_state *)&seq->private; - seq_printf(seq, "N: Number=%ld Name=%s", - (unsigned long)seq->private, handler->name); + seq_printf(seq, "N: Number=%u Name=%s", state->pos, handler->name); if (handler->fops) seq_printf(seq, " Minor=%d", handler->minor); seq_putc(seq, '\n'); return 0; } + static const struct seq_operations input_handlers_seq_ops = { .start = input_handlers_seq_start, .next = input_handlers_seq_next, - .stop = input_handlers_seq_stop, + .stop = input_seq_stop, .show = input_handlers_seq_show, }; @@ -1090,14 +1174,23 @@ static int input_print_bitmap(char *buf, int buf_size, unsigned long *bitmap, { int i; int len = 0; + bool skip_empty = true; + + for (i = BITS_TO_LONGS(max) - 1; i >= 0; i--) { + len += input_bits_to_string(buf + len, max(buf_size - len, 0), + bitmap[i], skip_empty); + if (len) { + skip_empty = false; + if (i > 0) + len += snprintf(buf + len, max(buf_size - len, 0), " "); + } + } - for (i = BITS_TO_LONGS(max) - 1; i > 0; i--) - if (bitmap[i]) - break; - - for (; i >= 0; i--) - len += snprintf(buf + len, max(buf_size - len, 0), - "%lx%s", bitmap[i], i > 0 ? " " : ""); + /* + * If no output was produced print a single 0. + */ + if (len == 0) + len = snprintf(buf, buf_size, "%d", 0); if (add_cr) len += snprintf(buf + len, max(buf_size - len, 0), "\n"); @@ -1112,7 +1205,8 @@ static ssize_t input_dev_show_cap_##bm(struct device *dev, \ { \ struct input_dev *input_dev = to_input_dev(dev); \ int len = input_print_bitmap(buf, PAGE_SIZE, \ - input_dev->bm##bit, ev##_MAX, 1); \ + input_dev->bm##bit, ev##_MAX, \ + true); \ return min_t(int, len, PAGE_SIZE); \ } \ static DEVICE_ATTR(bm, S_IRUGO, input_dev_show_cap_##bm, NULL) @@ -1176,7 +1270,7 @@ static int input_add_uevent_bm_var(struct kobj_uevent_env *env, len = input_print_bitmap(&env->buf[env->buflen - 1], sizeof(env->buf) - env->buflen, - bitmap, max, 0); + bitmap, max, false); if (len >= (sizeof(env->buf) - env->buflen)) return -ENOMEM; @@ -1260,17 +1354,24 @@ static int input_dev_uevent(struct device *device, struct kobj_uevent_env *env) return 0; } -#define INPUT_DO_TOGGLE(dev, type, bits, on) \ - do { \ - int i; \ - if (!test_bit(EV_##type, dev->evbit)) \ - break; \ - for (i = 0; i < type##_MAX; i++) { \ - if (!test_bit(i, dev->bits##bit) || \ - !test_bit(i, dev->bits)) \ - continue; \ - dev->event(dev, EV_##type, i, on); \ - } \ +#define INPUT_DO_TOGGLE(dev, type, bits, on) \ + do { \ + int i; \ + bool active; \ + \ + if (!test_bit(EV_##type, dev->evbit)) \ + break; \ + \ + for (i = 0; i < type##_MAX; i++) { \ + if (!test_bit(i, dev->bits##bit)) \ + continue; \ + \ + active = test_bit(i, dev->bits); \ + if (!active && !on) \ + continue; \ + \ + dev->event(dev, EV_##type, i, on ? active : 0); \ + } \ } while (0) #ifdef CONFIG_PM @@ -1619,6 +1720,38 @@ void input_unregister_handler(struct input_handler *handler) EXPORT_SYMBOL(input_unregister_handler); /** + * input_handler_for_each_handle - handle iterator + * @handler: input handler to iterate + * @data: data for the callback + * @fn: function to be called for each handle + * + * Iterate over @bus's list of devices, and call @fn for each, passing + * it @data and stop when @fn returns a non-zero value. The function is + * using RCU to traverse the list and therefore may be usind in atonic + * contexts. The @fn callback is invoked from RCU critical section and + * thus must not sleep. + */ +int input_handler_for_each_handle(struct input_handler *handler, void *data, + int (*fn)(struct input_handle *, void *)) +{ + struct input_handle *handle; + int retval = 0; + + rcu_read_lock(); + + list_for_each_entry_rcu(handle, &handler->h_list, h_node) { + retval = fn(handle, data); + if (retval) + break; + } + + rcu_read_unlock(); + + return retval; +} +EXPORT_SYMBOL(input_handler_for_each_handle); + +/** * input_register_handle - register a new input handle * @handle: handle to register * @@ -1651,7 +1784,7 @@ int input_register_handle(struct input_handle *handle) * we can't be racing with input_unregister_handle() * and so separate lock is not needed here. */ - list_add_tail(&handle->h_node, &handler->h_list); + list_add_tail_rcu(&handle->h_node, &handler->h_list); if (handler->start) handler->start(handle); @@ -1674,7 +1807,7 @@ void input_unregister_handle(struct input_handle *handle) { struct input_dev *dev = handle->dev; - list_del_init(&handle->h_node); + list_del_rcu(&handle->h_node); /* * Take dev->mutex to prevent race with input_release_device(). @@ -1682,6 +1815,7 @@ void input_unregister_handle(struct input_handle *handle) mutex_lock(&dev->mutex); list_del_rcu(&handle->d_node); mutex_unlock(&dev->mutex); + synchronize_rcu(); } EXPORT_SYMBOL(input_unregister_handle); |