From b3074c0a3f020766c05c1249a31212bff4a77bea Mon Sep 17 00:00:00 2001 From: =?utf8?q?David=20H=C3=A4rdeman?= Date: Fri, 2 Apr 2010 15:58:28 -0300 Subject: [PATCH] V4L/DVB: drivers/media/IR - improve keytable code MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The attached patch rewrites much of the keytable code in drivers/media/IR/ir-keytable.c. The scancodes are now inserted into the array in sorted order which allows for a binary search on lookup. The code has also been shrunk by about 150 lines. In addition it fixes the following bugs: Any use of ir_seek_table() was racy. ir_dev->driver_name is leaked between ir_input_register() and ir_input_unregister(). ir_setkeycode() unconditionally does clear_bit() on dev->keybit when removing a mapping, but there might be another mapping with a different scancode and the same keycode. This version has been updated to incorporate patch feedback from Mauro Carvalho Chehab. [mchehab@redhat.com: Fix a conflict with RC keytable breakup patches and input changes] Signed-off-by: David Härdeman Signed-off-by: Mauro Carvalho Chehab --- drivers/media/IR/ir-keytable.c | 518 +++++++++++++++-------------------------- include/media/ir-core.h | 4 +- 2 files changed, 191 insertions(+), 331 deletions(-) diff --git a/drivers/media/IR/ir-keytable.c b/drivers/media/IR/ir-keytable.c index 5d4ddc9..10e4be2 100644 --- a/drivers/media/IR/ir-keytable.c +++ b/drivers/media/IR/ir-keytable.c @@ -17,344 +17,214 @@ #include #include -#define IR_TAB_MIN_SIZE 32 -#define IR_TAB_MAX_SIZE 1024 +/* Sizes are in bytes, 256 bytes allows for 32 entries on x64 */ +#define IR_TAB_MIN_SIZE 256 +#define IR_TAB_MAX_SIZE 8192 /** - * ir_seek_table() - returns the element order on the table - * @rc_tab: the ir_scancode_table with the keymap to be used - * @scancode: the scancode that we're seeking + * ir_resize_table() - resizes a scancode table if necessary + * @rc_tab: the ir_scancode_table to resize + * @return: zero on success or a negative error code * - * This routine is used by the input routines when a key is pressed at the - * IR. The scancode is received and needs to be converted into a keycode. - * If the key is not found, it returns KEY_UNKNOWN. Otherwise, returns the - * corresponding keycode from the table. + * This routine will shrink the ir_scancode_table if it has lots of + * unused entries and grow it if it is full. */ -static int ir_seek_table(struct ir_scancode_table *rc_tab, u32 scancode) +static int ir_resize_table(struct ir_scancode_table *rc_tab) { - int rc; - unsigned long flags; - struct ir_scancode *keymap = rc_tab->scan; + unsigned int oldalloc = rc_tab->alloc; + unsigned int newalloc = oldalloc; + struct ir_scancode *oldscan = rc_tab->scan; + struct ir_scancode *newscan; + + if (rc_tab->size == rc_tab->len) { + /* All entries in use -> grow keytable */ + if (rc_tab->alloc >= IR_TAB_MAX_SIZE) + return -ENOMEM; - spin_lock_irqsave(&rc_tab->lock, flags); + newalloc *= 2; + IR_dprintk(1, "Growing table to %u bytes\n", newalloc); + } - /* FIXME: replace it by a binary search */ + if ((rc_tab->len * 3 < rc_tab->size) && (oldalloc > IR_TAB_MIN_SIZE)) { + /* Less than 1/3 of entries in use -> shrink keytable */ + newalloc /= 2; + IR_dprintk(1, "Shrinking table to %u bytes\n", newalloc); + } - for (rc = 0; rc < rc_tab->size; rc++) - if (keymap[rc].scancode == scancode) - goto exit; + if (newalloc == oldalloc) + return 0; - /* Not found */ - rc = -EINVAL; + newscan = kmalloc(newalloc, GFP_ATOMIC); + if (!newscan) { + IR_dprintk(1, "Failed to kmalloc %u bytes\n", newalloc); + return -ENOMEM; + } -exit: - spin_unlock_irqrestore(&rc_tab->lock, flags); - return rc; + memcpy(newscan, rc_tab->scan, rc_tab->len * sizeof(struct ir_scancode)); + rc_tab->scan = newscan; + rc_tab->alloc = newalloc; + rc_tab->size = rc_tab->alloc / sizeof(struct ir_scancode); + kfree(oldscan); + return 0; } /** - * ir_roundup_tablesize() - gets an optimum value for the table size - * @n_elems: minimum number of entries to store keycodes - * - * This routine is used to choose the keycode table size. + * ir_do_setkeycode() - internal function to set a keycode in the + * scancode->keycode table + * @dev: the struct input_dev device descriptor + * @rc_tab: the struct ir_scancode_table to set the keycode in + * @scancode: the scancode for the ir command + * @keycode: the keycode for the ir command + * @return: -EINVAL if the keycode could not be inserted, otherwise zero. * - * In order to have some empty space for new keycodes, - * and knowing in advance that kmalloc allocates only power of two - * segments, it optimizes the allocated space to have some spare space - * for those new keycodes by using the maximum number of entries that - * will be effectively be allocated by kmalloc. - * In order to reduce the quantity of table resizes, it has a minimum - * table size of IR_TAB_MIN_SIZE. + * This routine is used internally to manipulate the scancode->keycode table. + * The caller has to hold @rc_tab->lock. */ -static int ir_roundup_tablesize(int n_elems) +static int ir_do_setkeycode(struct input_dev *dev, + struct ir_scancode_table *rc_tab, + unsigned scancode, unsigned keycode) { - size_t size; + unsigned int i; + int old_keycode = KEY_RESERVED; + + /* First check if we already have a mapping for this ir command */ + for (i = 0; i < rc_tab->len; i++) { + /* Keytable is sorted from lowest to highest scancode */ + if (rc_tab->scan[i].scancode > scancode) + break; + else if (rc_tab->scan[i].scancode < scancode) + continue; - if (n_elems < IR_TAB_MIN_SIZE) - n_elems = IR_TAB_MIN_SIZE; + old_keycode = rc_tab->scan[i].keycode; + rc_tab->scan[i].keycode = keycode; - /* - * As kmalloc only allocates sizes of power of two, get as - * much entries as possible for the allocated memory segment - */ - size = roundup_pow_of_two(n_elems * sizeof(struct ir_scancode)); - n_elems = size / sizeof(struct ir_scancode); + /* Did the user wish to remove the mapping? */ + if (keycode == KEY_RESERVED || keycode == KEY_UNKNOWN) { + rc_tab->len--; + memmove(&rc_tab->scan[i], &rc_tab->scan[i + 1], + (rc_tab->len - i) * sizeof(struct ir_scancode)); + } - return n_elems; -} - -/** - * ir_copy_table() - copies a keytable, discarding the unused entries - * @destin: destin table - * @origin: origin table - * - * Copies all entries where the keycode is not KEY_UNKNOWN/KEY_RESERVED - * Also copies table size and table protocol. - * NOTE: It shouldn't copy the lock field - */ - -static int ir_copy_table(struct ir_scancode_table *destin, - const struct ir_scancode_table *origin) -{ - int i, j = 0; + /* Possibly shrink the keytable, failure is not a problem */ + ir_resize_table(rc_tab); + break; + } - for (i = 0; i < origin->size; i++) { - if (origin->scan[i].keycode == KEY_UNKNOWN || - origin->scan[i].keycode == KEY_RESERVED) - continue; + if (old_keycode == KEY_RESERVED) { + /* No previous mapping found, we might need to grow the table */ + if (ir_resize_table(rc_tab)) + return -ENOMEM; - memcpy(&destin->scan[j], &origin->scan[i], sizeof(struct ir_scancode)); - j++; + /* i is the proper index to insert our new keycode */ + memmove(&rc_tab->scan[i + 1], &rc_tab->scan[i], + (rc_tab->len - i) * sizeof(struct ir_scancode)); + rc_tab->scan[i].scancode = scancode; + rc_tab->scan[i].keycode = keycode; + rc_tab->len++; + set_bit(keycode, dev->keybit); + } else { + /* A previous mapping was updated... */ + clear_bit(old_keycode, dev->keybit); + /* ...but another scancode might use the same keycode */ + for (i = 0; i < rc_tab->len; i++) { + if (rc_tab->scan[i].keycode == old_keycode) { + set_bit(old_keycode, dev->keybit); + break; + } + } } - destin->size = j; - destin->ir_type = origin->ir_type; - - IR_dprintk(1, "Copied %d scancodes to the new keycode table\n", destin->size); return 0; } /** - * ir_getkeycode() - get a keycode at the evdev scancode ->keycode table + * ir_setkeycode() - set a keycode in the scancode->keycode table * @dev: the struct input_dev device descriptor * @scancode: the desired scancode - * @keycode: the keycode to be retorned. + * @keycode: result + * @return: -EINVAL if the keycode could not be inserted, otherwise zero. * - * This routine is used to handle evdev EVIOCGKEY ioctl. - * If the key is not found, returns -EINVAL, otherwise, returns 0. + * This routine is used to handle evdev EVIOCSKEY ioctl. */ -static int ir_getkeycode(struct input_dev *dev, - unsigned int scancode, unsigned int *keycode) +static int ir_setkeycode(struct input_dev *dev, + unsigned int scancode, unsigned int keycode) { - int elem; + int rc; + unsigned long flags; struct ir_input_dev *ir_dev = input_get_drvdata(dev); struct ir_scancode_table *rc_tab = &ir_dev->rc_tab; - elem = ir_seek_table(rc_tab, scancode); - if (elem >= 0) { - *keycode = rc_tab->scan[elem].keycode; - return 0; - } - - /* - * Scancode not found and table can't be expanded - */ - if (elem < 0 && rc_tab->size == IR_TAB_MAX_SIZE) - return -EINVAL; - - /* - * If is there extra space, returns KEY_RESERVED, - * otherwise, input core won't let ir_setkeycode to work - */ - *keycode = KEY_RESERVED; - return 0; -} - -/** - * ir_is_resize_needed() - Check if the table needs rezise - * @table: keycode table that may need to resize - * @n_elems: minimum number of entries to store keycodes - * - * Considering that kmalloc uses power of two storage areas, this - * routine detects if the real alloced size will change. If not, it - * just returns without doing nothing. Otherwise, it will extend or - * reduce the table size to meet the new needs. - * - * It returns 0 if no resize is needed, 1 otherwise. - */ -static int ir_is_resize_needed(struct ir_scancode_table *table, int n_elems) -{ - int cur_size = ir_roundup_tablesize(table->size); - int new_size = ir_roundup_tablesize(n_elems); - - if (cur_size == new_size) - return 0; - - /* Resize is needed */ - return 1; -} - -/** - * ir_delete_key() - remove a keycode from the table - * @rc_tab: keycode table - * @elem: element to be removed - * - */ -static void ir_delete_key(struct ir_scancode_table *rc_tab, int elem) -{ - unsigned long flags = 0; - int newsize = rc_tab->size - 1; - int resize = ir_is_resize_needed(rc_tab, newsize); - struct ir_scancode *oldkeymap = rc_tab->scan; - struct ir_scancode *newkeymap = NULL; - - if (resize) - newkeymap = kzalloc(ir_roundup_tablesize(newsize) * - sizeof(*newkeymap), GFP_ATOMIC); - - /* There's no memory for resize. Keep the old table */ - if (!resize || !newkeymap) { - newkeymap = oldkeymap; - - /* We'll modify the live table. Lock it */ - spin_lock_irqsave(&rc_tab->lock, flags); - } - - /* - * Copy the elements before the one that will be deleted - * if (!resize), both oldkeymap and newkeymap points - * to the same place, so, there's no need to copy - */ - if (resize && elem > 0) - memcpy(newkeymap, oldkeymap, - elem * sizeof(*newkeymap)); - - /* - * Copy the other elements overwriting the element to be removed - * This operation applies to both resize and non-resize case - */ - if (elem < newsize) - memcpy(&newkeymap[elem], &oldkeymap[elem + 1], - (newsize - elem) * sizeof(*newkeymap)); - - if (resize) { - /* - * As the copy happened to a temporary table, only here - * it needs to lock while replacing the table pointers - * to use the new table - */ - spin_lock_irqsave(&rc_tab->lock, flags); - rc_tab->size = newsize; - rc_tab->scan = newkeymap; - spin_unlock_irqrestore(&rc_tab->lock, flags); - - /* Frees the old keytable */ - kfree(oldkeymap); - } else { - rc_tab->size = newsize; - spin_unlock_irqrestore(&rc_tab->lock, flags); - } + spin_lock_irqsave(&rc_tab->lock, flags); + rc = ir_do_setkeycode(dev, rc_tab, scancode, keycode); + spin_unlock_irqrestore(&rc_tab->lock, flags); + return rc; } /** - * ir_insert_key() - insert a keycode at the table - * @rc_tab: keycode table - * @scancode: the desired scancode - * @keycode: the keycode to be retorned. + * ir_setkeytable() - sets several entries in the scancode->keycode table + * @dev: the struct input_dev device descriptor + * @to: the struct ir_scancode_table to copy entries to + * @from: the struct ir_scancode_table to copy entries from + * @return: -EINVAL if all keycodes could not be inserted, otherwise zero. * + * This routine is used to handle table initialization. */ -static int ir_insert_key(struct ir_scancode_table *rc_tab, - int scancode, int keycode) +static int ir_setkeytable(struct input_dev *dev, + struct ir_scancode_table *to, + const struct ir_scancode_table *from) { + struct ir_input_dev *ir_dev = input_get_drvdata(dev); + struct ir_scancode_table *rc_tab = &ir_dev->rc_tab; unsigned long flags; - int elem = rc_tab->size; - int newsize = rc_tab->size + 1; - int resize = ir_is_resize_needed(rc_tab, newsize); - struct ir_scancode *oldkeymap = rc_tab->scan; - struct ir_scancode *newkeymap; - - if (resize) { - newkeymap = kzalloc(ir_roundup_tablesize(newsize) * - sizeof(*newkeymap), GFP_ATOMIC); - if (!newkeymap) - return -ENOMEM; - - memcpy(newkeymap, oldkeymap, - rc_tab->size * sizeof(*newkeymap)); - } else - newkeymap = oldkeymap; - - /* Stores the new code at the table */ - IR_dprintk(1, "#%d: New scan 0x%04x with key 0x%04x\n", - rc_tab->size, scancode, keycode); + unsigned int i; + int rc = 0; spin_lock_irqsave(&rc_tab->lock, flags); - rc_tab->size = newsize; - if (resize) { - rc_tab->scan = newkeymap; - kfree(oldkeymap); + for (i = 0; i < from->size; i++) { + rc = ir_do_setkeycode(dev, to, from->scan[i].scancode, + from->scan[i].keycode); + if (rc) + break; } - newkeymap[elem].scancode = scancode; - newkeymap[elem].keycode = keycode; spin_unlock_irqrestore(&rc_tab->lock, flags); - - return 0; + return rc; } /** - * ir_setkeycode() - set a keycode at the evdev scancode ->keycode table + * ir_getkeycode() - get a keycode from the scancode->keycode table * @dev: the struct input_dev device descriptor * @scancode: the desired scancode - * @keycode: the keycode to be retorned. + * @keycode: used to return the keycode, if found, or KEY_RESERVED + * @return: always returns zero. * - * This routine is used to handle evdev EVIOCSKEY ioctl. - * There's one caveat here: how can we increase the size of the table? - * If the key is not found, returns -EINVAL, otherwise, returns 0. + * This routine is used to handle evdev EVIOCGKEY ioctl. */ -static int ir_setkeycode(struct input_dev *dev, - unsigned int scancode, unsigned int keycode) +static int ir_getkeycode(struct input_dev *dev, + unsigned int scancode, unsigned int *keycode) { - int rc = 0; + int start, end, mid; + unsigned long flags; + int key = KEY_RESERVED; struct ir_input_dev *ir_dev = input_get_drvdata(dev); struct ir_scancode_table *rc_tab = &ir_dev->rc_tab; - struct ir_scancode *keymap = rc_tab->scan; - unsigned long flags; - - /* - * Handle keycode table deletions - * - * If userspace is adding a KEY_UNKNOWN or KEY_RESERVED, - * deal as a trial to remove an existing scancode attribution - * if table become too big, reduce it to save space - */ - if (keycode == KEY_UNKNOWN || keycode == KEY_RESERVED) { - rc = ir_seek_table(rc_tab, scancode); - if (rc < 0) - return 0; - - IR_dprintk(1, "#%d: Deleting scan 0x%04x\n", rc, scancode); - clear_bit(keymap[rc].keycode, dev->keybit); - ir_delete_key(rc_tab, rc); - - return 0; - } - - /* - * Handle keycode replacements - * - * If the scancode exists, just replace by the new value - */ - rc = ir_seek_table(rc_tab, scancode); - if (rc >= 0) { - IR_dprintk(1, "#%d: Replacing scan 0x%04x with key 0x%04x\n", - rc, scancode, keycode); - clear_bit(keymap[rc].keycode, dev->keybit); - - spin_lock_irqsave(&rc_tab->lock, flags); - keymap[rc].keycode = keycode; - spin_unlock_irqrestore(&rc_tab->lock, flags); - - set_bit(keycode, dev->keybit); - - return 0; + spin_lock_irqsave(&rc_tab->lock, flags); + start = 0; + end = rc_tab->len - 1; + while (start <= end) { + mid = (start + end) / 2; + if (rc_tab->scan[mid].scancode < scancode) + start = mid + 1; + else if (rc_tab->scan[mid].scancode > scancode) + end = mid - 1; + else { + key = rc_tab->scan[mid].keycode; + break; + } } + spin_unlock_irqrestore(&rc_tab->lock, flags); - /* - * Handle new scancode inserts - * - * reallocate table if needed and insert a new keycode - */ - - /* Avoid growing the table indefinitely */ - if (rc_tab->size + 1 > IR_TAB_MAX_SIZE) - return -EINVAL; - - rc = ir_insert_key(rc_tab, scancode, keycode); - if (rc < 0) - return rc; - set_bit(keycode, dev->keybit); - + *keycode = key; return 0; } @@ -370,24 +240,12 @@ static int ir_setkeycode(struct input_dev *dev, */ u32 ir_g_keycode_from_table(struct input_dev *dev, u32 scancode) { - struct ir_input_dev *ir_dev = input_get_drvdata(dev); - struct ir_scancode_table *rc_tab = &ir_dev->rc_tab; - struct ir_scancode *keymap = rc_tab->scan; - int elem; - - elem = ir_seek_table(rc_tab, scancode); - if (elem >= 0) { - IR_dprintk(1, "%s: scancode 0x%04x keycode 0x%02x\n", - dev->name, scancode, keymap[elem].keycode); - - return rc_tab->scan[elem].keycode; - } + int keycode; - printk(KERN_INFO "%s: unknown key for scancode 0x%04x\n", - dev->name, scancode); - - /* Reports userspace that an unknown keycode were got */ - return KEY_RESERVED; + ir_getkeycode(dev, scancode, &keycode); + IR_dprintk(1, "%s: scancode 0x%04x keycode 0x%02x\n", + dev->name, scancode, keycode); + return keycode; } EXPORT_SYMBOL_GPL(ir_g_keycode_from_table); @@ -477,8 +335,7 @@ int __ir_input_register(struct input_dev *input_dev, const char *driver_name) { struct ir_input_dev *ir_dev; - struct ir_scancode *keymap = rc_tab->scan; - int i, rc; + int rc; if (rc_tab->scan == NULL || !rc_tab->size) return -EINVAL; @@ -487,55 +344,55 @@ int __ir_input_register(struct input_dev *input_dev, if (!ir_dev) return -ENOMEM; - spin_lock_init(&ir_dev->rc_tab.lock); + ir_dev->driver_name = kasprintf(GFP_KERNEL, "%s", driver_name); + if (!ir_dev->driver_name) { + rc = -ENOMEM; + goto out_dev; + } - ir_dev->driver_name = kmalloc(strlen(driver_name) + 1, GFP_KERNEL); - if (!ir_dev->driver_name) - return -ENOMEM; - strcpy(ir_dev->driver_name, driver_name); + input_dev->getkeycode = ir_getkeycode; + input_dev->setkeycode = ir_setkeycode; + input_set_drvdata(input_dev, ir_dev); + + spin_lock_init(&ir_dev->rc_tab.lock); ir_dev->rc_tab.name = rc_tab->name; - ir_dev->rc_tab.size = ir_roundup_tablesize(rc_tab->size); - ir_dev->rc_tab.scan = kzalloc(ir_dev->rc_tab.size * - sizeof(struct ir_scancode), GFP_KERNEL); + ir_dev->rc_tab.ir_type = rc_tab->ir_type; + ir_dev->rc_tab.alloc = roundup_pow_of_two(rc_tab->size * + sizeof(struct ir_scancode)); + ir_dev->rc_tab.scan = kmalloc(ir_dev->rc_tab.alloc, GFP_KERNEL); + ir_dev->rc_tab.size = ir_dev->rc_tab.alloc / sizeof(struct ir_scancode); + if (!ir_dev->rc_tab.scan) { - kfree(ir_dev); - return -ENOMEM; + rc = -ENOMEM; + goto out_name; } - IR_dprintk(1, "Allocated space for %d keycode entries (%zd bytes)\n", - ir_dev->rc_tab.size, - ir_dev->rc_tab.size * sizeof(ir_dev->rc_tab.scan)); + IR_dprintk(1, "Allocated space for %u keycode entries (%u bytes)\n", + ir_dev->rc_tab.size, ir_dev->rc_tab.alloc); + + set_bit(EV_KEY, input_dev->evbit); + if (ir_setkeytable(input_dev, &ir_dev->rc_tab, rc_tab)) { + rc = -ENOMEM; + goto out_table; + } - ir_copy_table(&ir_dev->rc_tab, rc_tab); ir_dev->props = props; if (props && props->open) input_dev->open = ir_open; if (props && props->close) input_dev->close = ir_close; - /* set the bits for the keys */ - IR_dprintk(1, "key map size: %d\n", rc_tab->size); - for (i = 0; i < rc_tab->size; i++) { - IR_dprintk(1, "#%d: setting bit for keycode 0x%04x\n", - i, keymap[i].keycode); - set_bit(keymap[i].keycode, input_dev->keybit); - } - clear_bit(0, input_dev->keybit); - - set_bit(EV_KEY, input_dev->evbit); - - input_dev->getkeycode = ir_getkeycode; - input_dev->setkeycode = ir_setkeycode; - input_set_drvdata(input_dev, ir_dev); - rc = ir_register_class(input_dev); if (rc < 0) - goto err; + goto out_table; return 0; -err: - kfree(rc_tab->scan); +out_table: + kfree(ir_dev->rc_tab.scan); +out_name: + kfree(ir_dev->driver_name); +out_dev: kfree(ir_dev); return rc; } @@ -564,6 +421,7 @@ void ir_input_unregister(struct input_dev *dev) ir_unregister_class(dev); + kfree(ir_dev->driver_name); kfree(ir_dev); } EXPORT_SYMBOL_GPL(ir_input_unregister); diff --git a/include/media/ir-core.h b/include/media/ir-core.h index c6b8e17..7a0be8d 100644 --- a/include/media/ir-core.h +++ b/include/media/ir-core.h @@ -47,7 +47,9 @@ struct ir_scancode { struct ir_scancode_table { struct ir_scancode *scan; - int size; + unsigned int size; /* Max number of entries */ + unsigned int len; /* Used number of entries */ + unsigned int alloc; /* Size of *scan in bytes */ u64 ir_type; char *name; spinlock_t lock; -- 1.8.2.3