From 45465487897a1c6d508b14b904dc5777f7ec7e04 Mon Sep 17 00:00:00 2001 From: Stefani Seibold Date: Mon, 21 Dec 2009 14:37:26 -0800 Subject: kfifo: move struct kfifo in place This is a new generic kernel FIFO implementation. The current kernel fifo API is not very widely used, because it has to many constrains. Only 17 files in the current 2.6.31-rc5 used it. FIFO's are like list's a very basic thing and a kfifo API which handles the most use case would save a lot of development time and memory resources. I think this are the reasons why kfifo is not in use: - The API is to simple, important functions are missing - A fifo can be only allocated dynamically - There is a requirement of a spinlock whether you need it or not - There is no support for data records inside a fifo So I decided to extend the kfifo in a more generic way without blowing up the API to much. The new API has the following benefits: - Generic usage: For kernel internal use and/or device driver. - Provide an API for the most use case. - Slim API: The whole API provides 25 functions. - Linux style habit. - DECLARE_KFIFO, DEFINE_KFIFO and INIT_KFIFO Macros - Direct copy_to_user from the fifo and copy_from_user into the fifo. - The kfifo itself is an in place member of the using data structure, this save an indirection access and does not waste the kernel allocator. - Lockless access: if only one reader and one writer is active on the fifo, which is the common use case, no additional locking is necessary. - Remove spinlock - give the user the freedom of choice what kind of locking to use if one is required. - Ability to handle records. Three type of records are supported: - Variable length records between 0-255 bytes, with a record size field of 1 bytes. - Variable length records between 0-65535 bytes, with a record size field of 2 bytes. - Fixed size records, which no record size field. - Preserve memory resource. - Performance! - Easy to use! This patch: Since most users want to have the kfifo as part of another object, reorganize the code to allow including struct kfifo in another data structure. This requires changing the kfifo_alloc and kfifo_init prototypes so that we pass an existing kfifo pointer into them. This patch changes the implementation and all existing users. [akpm@linux-foundation.org: fix warning] Signed-off-by: Stefani Seibold Acked-by: Greg Kroah-Hartman Acked-by: Mauro Carvalho Chehab Acked-by: Andi Kleen Acked-by: Arnd Bergmann Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/platform/x86/sony-laptop.c | 46 +++++++++++++++++++------------------- 1 file changed, 23 insertions(+), 23 deletions(-) (limited to 'drivers/platform/x86/sony-laptop.c') diff --git a/drivers/platform/x86/sony-laptop.c b/drivers/platform/x86/sony-laptop.c index 7a2cc8a5c97..04625a048e7 100644 --- a/drivers/platform/x86/sony-laptop.c +++ b/drivers/platform/x86/sony-laptop.c @@ -142,7 +142,7 @@ struct sony_laptop_input_s { atomic_t users; struct input_dev *jog_dev; struct input_dev *key_dev; - struct kfifo *fifo; + struct kfifo fifo; spinlock_t fifo_lock; struct workqueue_struct *wq; }; @@ -300,7 +300,7 @@ static void do_sony_laptop_release_key(struct work_struct *work) { struct sony_laptop_keypress kp; - while (kfifo_get(sony_laptop_input.fifo, (unsigned char *)&kp, + while (kfifo_get(&sony_laptop_input.fifo, (unsigned char *)&kp, sizeof(kp)) == sizeof(kp)) { msleep(10); input_report_key(kp.dev, kp.key, 0); @@ -362,7 +362,7 @@ static void sony_laptop_report_input_event(u8 event) /* we emit the scancode so we can always remap the key */ input_event(kp.dev, EV_MSC, MSC_SCAN, event); input_sync(kp.dev); - kfifo_put(sony_laptop_input.fifo, + kfifo_put(&sony_laptop_input.fifo, (unsigned char *)&kp, sizeof(kp)); if (!work_pending(&sony_laptop_release_key_work)) @@ -385,12 +385,11 @@ static int sony_laptop_setup_input(struct acpi_device *acpi_device) /* kfifo */ spin_lock_init(&sony_laptop_input.fifo_lock); - sony_laptop_input.fifo = - kfifo_alloc(SONY_LAPTOP_BUF_SIZE, GFP_KERNEL, + error = + kfifo_alloc(&sony_laptop_input.fifo, SONY_LAPTOP_BUF_SIZE, GFP_KERNEL, &sony_laptop_input.fifo_lock); - if (IS_ERR(sony_laptop_input.fifo)) { + if (error) { printk(KERN_ERR DRV_PFX "kfifo_alloc failed\n"); - error = PTR_ERR(sony_laptop_input.fifo); goto err_dec_users; } @@ -474,7 +473,7 @@ err_destroy_wq: destroy_workqueue(sony_laptop_input.wq); err_free_kfifo: - kfifo_free(sony_laptop_input.fifo); + kfifo_free(&sony_laptop_input.fifo); err_dec_users: atomic_dec(&sony_laptop_input.users); @@ -500,7 +499,7 @@ static void sony_laptop_remove_input(void) } destroy_workqueue(sony_laptop_input.wq); - kfifo_free(sony_laptop_input.fifo); + kfifo_free(&sony_laptop_input.fifo); } /*********** Platform Device ***********/ @@ -2079,7 +2078,7 @@ static struct attribute_group spic_attribute_group = { struct sonypi_compat_s { struct fasync_struct *fifo_async; - struct kfifo *fifo; + struct kfifo fifo; spinlock_t fifo_lock; wait_queue_head_t fifo_proc_list; atomic_t open_count; @@ -2104,12 +2103,12 @@ static int sonypi_misc_open(struct inode *inode, struct file *file) /* Flush input queue on first open */ unsigned long flags; - spin_lock_irqsave(sonypi_compat.fifo->lock, flags); + spin_lock_irqsave(&sonypi_compat.fifo_lock, flags); if (atomic_inc_return(&sonypi_compat.open_count) == 1) - __kfifo_reset(sonypi_compat.fifo); + __kfifo_reset(&sonypi_compat.fifo); - spin_unlock_irqrestore(sonypi_compat.fifo->lock, flags); + spin_unlock_irqrestore(&sonypi_compat.fifo_lock, flags); return 0; } @@ -2120,17 +2119,17 @@ static ssize_t sonypi_misc_read(struct file *file, char __user *buf, ssize_t ret; unsigned char c; - if ((kfifo_len(sonypi_compat.fifo) == 0) && + if ((kfifo_len(&sonypi_compat.fifo) == 0) && (file->f_flags & O_NONBLOCK)) return -EAGAIN; ret = wait_event_interruptible(sonypi_compat.fifo_proc_list, - kfifo_len(sonypi_compat.fifo) != 0); + kfifo_len(&sonypi_compat.fifo) != 0); if (ret) return ret; while (ret < count && - (kfifo_get(sonypi_compat.fifo, &c, sizeof(c)) == sizeof(c))) { + (kfifo_get(&sonypi_compat.fifo, &c, sizeof(c)) == sizeof(c))) { if (put_user(c, buf++)) return -EFAULT; ret++; @@ -2147,7 +2146,7 @@ static ssize_t sonypi_misc_read(struct file *file, char __user *buf, static unsigned int sonypi_misc_poll(struct file *file, poll_table *wait) { poll_wait(file, &sonypi_compat.fifo_proc_list, wait); - if (kfifo_len(sonypi_compat.fifo)) + if (kfifo_len(&sonypi_compat.fifo)) return POLLIN | POLLRDNORM; return 0; } @@ -2309,7 +2308,7 @@ static struct miscdevice sonypi_misc_device = { static void sonypi_compat_report_event(u8 event) { - kfifo_put(sonypi_compat.fifo, (unsigned char *)&event, sizeof(event)); + kfifo_put(&sonypi_compat.fifo, (unsigned char *)&event, sizeof(event)); kill_fasync(&sonypi_compat.fifo_async, SIGIO, POLL_IN); wake_up_interruptible(&sonypi_compat.fifo_proc_list); } @@ -2319,11 +2318,12 @@ static int sonypi_compat_init(void) int error; spin_lock_init(&sonypi_compat.fifo_lock); - sonypi_compat.fifo = kfifo_alloc(SONY_LAPTOP_BUF_SIZE, GFP_KERNEL, + error = + kfifo_alloc(&sonypi_compat.fifo, SONY_LAPTOP_BUF_SIZE, GFP_KERNEL, &sonypi_compat.fifo_lock); - if (IS_ERR(sonypi_compat.fifo)) { + if (error) { printk(KERN_ERR DRV_PFX "kfifo_alloc failed\n"); - return PTR_ERR(sonypi_compat.fifo); + return error; } init_waitqueue_head(&sonypi_compat.fifo_proc_list); @@ -2342,14 +2342,14 @@ static int sonypi_compat_init(void) return 0; err_free_kfifo: - kfifo_free(sonypi_compat.fifo); + kfifo_free(&sonypi_compat.fifo); return error; } static void sonypi_compat_exit(void) { misc_deregister(&sonypi_misc_device); - kfifo_free(sonypi_compat.fifo); + kfifo_free(&sonypi_compat.fifo); } #else static int sonypi_compat_init(void) { return 0; } -- cgit v1.2.3