ixgbe: Cleanup incorrect header comments
[safe/jmp/linux-2.6] / drivers / input / input.c
index 16ec33f..30b503b 100644 (file)
 #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);