diff options
Diffstat (limited to 'samples')
| -rw-r--r-- | samples/Kconfig | 10 | ||||
| -rw-r--r-- | samples/Makefile | 2 | ||||
| -rw-r--r-- | samples/kfifo/Makefile | 1 | ||||
| -rw-r--r-- | samples/kfifo/bytestream-example.c | 163 | ||||
| -rw-r--r-- | samples/kfifo/dma-example.c | 115 | ||||
| -rw-r--r-- | samples/kfifo/inttype-example.c | 157 | ||||
| -rw-r--r-- | samples/kfifo/record-example.c | 167 |
7 files changed, 614 insertions, 1 deletions
diff --git a/samples/Kconfig b/samples/Kconfig index 8924f72..954a1d5 100644 --- a/samples/Kconfig +++ b/samples/Kconfig @@ -44,4 +44,14 @@ config SAMPLE_HW_BREAKPOINT help This builds kernel hardware breakpoint example modules. +config SAMPLE_KFIFO + tristate "Build kfifo examples -- loadable modules only" + depends on m + help + This config option will allow you to build a number of + different kfifo sample modules showing how to use the + generic kfifo API. + + If in doubt, say "N" here. + endif # SAMPLES diff --git a/samples/Makefile b/samples/Makefile index 0f15e6d..76b3c34 100644 --- a/samples/Makefile +++ b/samples/Makefile @@ -1,4 +1,4 @@ # Makefile for Linux samples code obj-$(CONFIG_SAMPLES) += kobject/ kprobes/ tracepoints/ trace_events/ \ - hw_breakpoint/ + hw_breakpoint/ kfifo/ diff --git a/samples/kfifo/Makefile b/samples/kfifo/Makefile new file mode 100644 index 0000000..bcc9484 --- /dev/null +++ b/samples/kfifo/Makefile @@ -0,0 +1 @@ +obj-$(CONFIG_SAMPLE_KFIFO) += bytestream-example.o dma-example.o inttype-example.o record-example.o diff --git a/samples/kfifo/bytestream-example.c b/samples/kfifo/bytestream-example.c new file mode 100644 index 0000000..642eef3 --- /dev/null +++ b/samples/kfifo/bytestream-example.c @@ -0,0 +1,163 @@ +/* + * Sample kfifo byte stream implementation + * + * Copyright (C) 2010 Stefani Seibold <stefani@seibold.net> + * + * Released under the GPL version 2 only. + * + */ + +#include <linux/init.h> +#include <linux/module.h> +#include <linux/proc_fs.h> +#include <linux/mutex.h> +#include <linux/kfifo.h> + +/* + * This module shows how to create a byte stream fifo. + */ + +/* fifo size in elements (bytes) */ +#define FIFO_SIZE 32 + +/* name of the proc entry */ +#define PROC_FIFO "bytestream-fifo" + +/* lock for procfs read access */ +static DEFINE_MUTEX(read_lock); + +/* lock for procfs write access */ +static DEFINE_MUTEX(write_lock); + +/* + * define DYNAMIC in this example for a dynamically allocated fifo. + * + * Otherwise the fifo storage will be a part of the fifo structure. + */ +#if 0 +#define DYNAMIC +#endif + +#ifdef DYNAMIC +static struct kfifo test; +#else +static DECLARE_KFIFO(test, unsigned char, FIFO_SIZE); +#endif + +static int __init testfunc(void) +{ + unsigned char buf[6]; + unsigned char i; + unsigned int ret; + + printk(KERN_INFO "byte stream fifo test start\n"); + + /* put string into the fifo */ + kfifo_in(&test, "hello", 5); + + /* put values into the fifo */ + for (i = 0; i != 10; i++) + kfifo_put(&test, &i); + + /* show the number of used elements */ + printk(KERN_INFO "fifo len: %u\n", kfifo_len(&test)); + + /* get max of 5 bytes from the fifo */ + i = kfifo_out(&test, buf, 5); + printk(KERN_INFO "buf: %.*s\n", i, buf); + + /* get max of 2 elements from the fifo */ + ret = kfifo_out(&test, buf, 2); + printk(KERN_INFO "ret: %d\n", ret); + /* and put it back to the end of the fifo */ + ret = kfifo_in(&test, buf, ret); + printk(KERN_INFO "ret: %d\n", ret); + + /* put values into the fifo until is full */ + for (i = 20; kfifo_put(&test, &i); i++) + ; + + printk(KERN_INFO "queue len: %u\n", kfifo_len(&test)); + + /* print out all values in the fifo */ + while (kfifo_get(&test, &i)) + printk("%d ", i); + printk("\n"); + + return 0; +} + +static ssize_t fifo_write(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + int ret; + unsigned int copied; + + if (mutex_lock_interruptible(&write_lock)) + return -ERESTARTSYS; + + ret = kfifo_from_user(&test, buf, count, &copied); + + mutex_unlock(&write_lock); + + return ret ? ret : copied; +} + +static ssize_t fifo_read(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + int ret; + unsigned int copied; + + if (mutex_lock_interruptible(&read_lock)) + return -ERESTARTSYS; + + ret = kfifo_to_user(&test, buf, count, &copied); + + mutex_unlock(&read_lock); + + return ret ? ret : copied; +} + +static const struct file_operations fifo_fops = { + .owner = THIS_MODULE, + .read = fifo_read, + .write = fifo_write, +}; + +static int __init example_init(void) +{ +#ifdef DYNAMIC + int ret; + + ret = kfifo_alloc(&test, FIFO_SIZE, GFP_KERNEL); + if (ret) { + printk(KERN_ERR "error kfifo_alloc\n"); + return ret; + } +#else + INIT_KFIFO(test); +#endif + testfunc(); + + if (proc_create(PROC_FIFO, 0, NULL, &fifo_fops) == NULL) { +#ifdef DYNAMIC + kfifo_free(&test); +#endif + return -ENOMEM; + } + return 0; +} + +static void __exit example_exit(void) +{ + remove_proc_entry(PROC_FIFO, NULL); +#ifdef DYNAMIC + kfifo_free(&test); +#endif +} + +module_init(example_init); +module_exit(example_exit); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Stefani Seibold <stefani@seibold.net>"); diff --git a/samples/kfifo/dma-example.c b/samples/kfifo/dma-example.c new file mode 100644 index 0000000..b9482c2 --- /dev/null +++ b/samples/kfifo/dma-example.c @@ -0,0 +1,115 @@ +/* + * Sample fifo dma implementation + * + * Copyright (C) 2010 Stefani Seibold <stefani@seibold.net> + * + * Released under the GPL version 2 only. + * + */ + +#include <linux/init.h> +#include <linux/module.h> +#include <linux/kfifo.h> + +/* + * This module shows how to handle fifo dma operations. + */ + +/* fifo size in elements (bytes) */ +#define FIFO_SIZE 32 + +static struct kfifo fifo; + +static int __init example_init(void) +{ + int i; + unsigned int ret; + struct scatterlist sg[10]; + + printk(KERN_INFO "DMA fifo test start\n"); + + if (kfifo_alloc(&fifo, FIFO_SIZE, GFP_KERNEL)) { + printk(KERN_ERR "error kfifo_alloc\n"); + return 1; + } + + printk(KERN_INFO "queue size: %u\n", kfifo_size(&fifo)); + + kfifo_in(&fifo, "test", 4); + + for (i = 0; i != 9; i++) + kfifo_put(&fifo, &i); + + /* kick away first byte */ + ret = kfifo_get(&fifo, &i); + + printk(KERN_INFO "queue len: %u\n", kfifo_len(&fifo)); + + ret = kfifo_dma_in_prepare(&fifo, sg, ARRAY_SIZE(sg), FIFO_SIZE); + printk(KERN_INFO "DMA sgl entries: %d\n", ret); + + /* if 0 was returned, fifo is full and no sgl was created */ + if (ret) { + printk(KERN_INFO "scatterlist for receive:\n"); + for (i = 0; i < ARRAY_SIZE(sg); i++) { + printk(KERN_INFO + "sg[%d] -> " + "page_link 0x%.8lx offset 0x%.8x length 0x%.8x\n", + i, sg[i].page_link, sg[i].offset, sg[i].length); + + if (sg_is_last(&sg[i])) + break; + } + + /* but here your code to setup and exectute the dma operation */ + /* ... */ + + /* example: zero bytes received */ + ret = 0; + + /* finish the dma operation and update the received data */ + kfifo_dma_in_finish(&fifo, ret); + } + + ret = kfifo_dma_out_prepare(&fifo, sg, ARRAY_SIZE(sg), 8); + printk(KERN_INFO "DMA sgl entries: %d\n", ret); + + /* if 0 was returned, no data was available and no sgl was created */ + if (ret) { + printk(KERN_INFO "scatterlist for transmit:\n"); + for (i = 0; i < ARRAY_SIZE(sg); i++) { + printk(KERN_INFO + "sg[%d] -> " + "page_link 0x%.8lx offset 0x%.8x length 0x%.8x\n", + i, sg[i].page_link, sg[i].offset, sg[i].length); + + if (sg_is_last(&sg[i])) + break; + } + + /* but here your code to setup and exectute the dma operation */ + /* ... */ + + /* example: 5 bytes transmitted */ + ret = 5; + + /* finish the dma operation and update the transmitted data */ + kfifo_dma_out_finish(&fifo, ret); + } + + printk(KERN_INFO "queue len: %u\n", kfifo_len(&fifo)); + + return 0; +} + +static void __exit example_exit(void) +{ +#ifdef DYNAMIC + kfifo_free(&test); +#endif +} + +module_init(example_init); +module_exit(example_exit); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Stefani Seibold <stefani@seibold.net>"); diff --git a/samples/kfifo/inttype-example.c b/samples/kfifo/inttype-example.c new file mode 100644 index 0000000..d6c5b7d --- /dev/null +++ b/samples/kfifo/inttype-example.c @@ -0,0 +1,157 @@ +/* + * Sample kfifo int type implementation + * + * Copyright (C) 2010 Stefani Seibold <stefani@seibold.net> + * + * Released under the GPL version 2 only. + * + */ + +#include <linux/init.h> +#include <linux/module.h> +#include <linux/proc_fs.h> +#include <linux/mutex.h> +#include <linux/kfifo.h> + +/* + * This module shows how to create a int type fifo. + */ + +/* fifo size in elements (ints) */ +#define FIFO_SIZE 32 + +/* name of the proc entry */ +#define PROC_FIFO "int-fifo" + +/* lock for procfs read access */ +static DEFINE_MUTEX(read_lock); + +/* lock for procfs write access */ +static DEFINE_MUTEX(write_lock); + +/* + * define DYNAMIC in this example for a dynamically allocated fifo. + * + * Otherwise the fifo storage will be a part of the fifo structure. + */ +#if 0 +#define DYNAMIC +#endif + +#ifdef DYNAMIC +static DECLARE_KFIFO_PTR(test, int); +#else +static DEFINE_KFIFO(test, int, FIFO_SIZE); +#endif + +static int __init testfunc(void) +{ + int buf[6]; + int i; + unsigned int ret; + + printk(KERN_INFO "int fifo test start\n"); + + /* put values into the fifo */ + for (i = 0; i != 10; i++) + kfifo_put(&test, &i); + + /* show the number of used elements */ + printk(KERN_INFO "fifo len: %u\n", kfifo_len(&test)); + + /* get max of 2 elements from the fifo */ + ret = kfifo_out(&test, buf, 2); + printk(KERN_INFO "ret: %d\n", ret); + /* and put it back to the end of the fifo */ + ret = kfifo_in(&test, buf, ret); + printk(KERN_INFO "ret: %d\n", ret); + + for (i = 20; i != 30; i++) + kfifo_put(&test, &i); + + printk(KERN_INFO "queue len: %u\n", kfifo_len(&test)); + + /* show the first value without removing from the fifo */ + if (kfifo_peek(&test, &i)) + printk(KERN_INFO "%d\n", i); + + /* print out all values in the fifo */ + while (kfifo_get(&test, &i)) + printk("%d ", i); + printk("\n"); + + return 0; +} + +static ssize_t fifo_write(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + int ret; + unsigned int copied; + + if (mutex_lock_interruptible(&write_lock)) + return -ERESTARTSYS; + + ret = kfifo_from_user(&test, buf, count, &copied); + + mutex_unlock(&write_lock); + + return ret ? ret : copied; +} + +static ssize_t fifo_read(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + int ret; + unsigned int copied; + + if (mutex_lock_interruptible(&read_lock)) + return -ERESTARTSYS; + + ret = kfifo_to_user(&test, buf, count, &copied); + + mutex_unlock(&read_lock); + + return ret ? ret : copied; +} + +static const struct file_operations fifo_fops = { + .owner = THIS_MODULE, + .read = fifo_read, + .write = fifo_write, +}; + +static int __init example_init(void) +{ +#ifdef DYNAMIC + int ret; + + ret = kfifo_alloc(&test, FIFO_SIZE, GFP_KERNEL); + if (ret) { + printk(KERN_ERR "error kfifo_alloc\n"); + return ret; + } +#endif + testfunc(); + + if (proc_create(PROC_FIFO, 0, NULL, &fifo_fops) == NULL) { +#ifdef DYNAMIC + kfifo_free(&test); +#endif + return -ENOMEM; + } + return 0; +} + +static void __exit example_exit(void) +{ + remove_proc_entry(PROC_FIFO, NULL); +#ifdef DYNAMIC + kfifo_free(&test); +#endif +} + +module_init(example_init); +module_exit(example_exit); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Stefani Seibold <stefani@seibold.net>"); diff --git a/samples/kfifo/record-example.c b/samples/kfifo/record-example.c new file mode 100644 index 0000000..32c6e0b --- /dev/null +++ b/samples/kfifo/record-example.c @@ -0,0 +1,167 @@ +/* + * Sample dynamic sized record fifo implementation + * + * Copyright (C) 2010 Stefani Seibold <stefani@seibold.net> + * + * Released under the GPL version 2 only. + * + */ + +#include <linux/init.h> +#include <linux/module.h> +#include <linux/proc_fs.h> +#include <linux/mutex.h> +#include <linux/kfifo.h> + +/* + * This module shows how to create a variable sized record fifo. + */ + +/* fifo size in elements (bytes) */ +#define FIFO_SIZE 128 + +/* name of the proc entry */ +#define PROC_FIFO "record-fifo" + +/* lock for procfs read access */ +static DEFINE_MUTEX(read_lock); + +/* lock for procfs write access */ +static DEFINE_MUTEX(write_lock); + +/* + * define DYNAMIC in this example for a dynamically allocated fifo. + * + * Otherwise the fifo storage will be a part of the fifo structure. + */ +#if 0 +#define DYNAMIC +#endif + +/* + * struct kfifo_rec_ptr_1 and STRUCT_KFIFO_REC_1 can handle records of a + * length between 0 and 255 bytes. + * + * struct kfifo_rec_ptr_2 and STRUCT_KFIFO_REC_2 can handle records of a + * length between 0 and 65535 bytes. + */ + +#ifdef DYNAMIC +struct kfifo_rec_ptr_1 test; + +#else +typedef STRUCT_KFIFO_REC_1(FIFO_SIZE) mytest; + +static mytest test; +#endif + +static int __init testfunc(void) +{ + char buf[100]; + unsigned int i; + unsigned int ret; + struct { unsigned char buf[6]; } hello = { "hello" }; + + printk(KERN_INFO "record fifo test start\n"); + + kfifo_in(&test, &hello, sizeof(hello)); + + /* show the size of the next record in the fifo */ + printk(KERN_INFO "fifo peek len: %u\n", kfifo_peek_len(&test)); + + /* put in variable length data */ + for (i = 0; i < 10; i++) { + memset(buf, 'a' + i, i + 1); + kfifo_in(&test, buf, i + 1); + } + + printk(KERN_INFO "fifo len: %u\n", kfifo_len(&test)); + + /* show the first record without removing from the fifo */ + ret = kfifo_out_peek(&test, buf, sizeof(buf)); + if (ret) + printk(KERN_INFO "%.*s\n", ret, buf); + + /* print out all records in the fifo */ + while (!kfifo_is_empty(&test)) { + ret = kfifo_out(&test, buf, sizeof(buf)); + printk(KERN_INFO "%.*s\n", ret, buf); + } + + return 0; +} + +static ssize_t fifo_write(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + int ret; + unsigned int copied; + + if (mutex_lock_interruptible(&write_lock)) + return -ERESTARTSYS; + + ret = kfifo_from_user(&test, buf, count, &copied); + + mutex_unlock(&write_lock); + + return ret ? ret : copied; +} + +static ssize_t fifo_read(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + int ret; + unsigned int copied; + + if (mutex_lock_interruptible(&read_lock)) + return -ERESTARTSYS; + + ret = kfifo_to_user(&test, buf, count, &copied); + + mutex_unlock(&read_lock); + + return ret ? ret : copied; +} + +static const struct file_operations fifo_fops = { + .owner = THIS_MODULE, + .read = fifo_read, + .write = fifo_write, +}; + +static int __init example_init(void) +{ +#ifdef DYNAMIC + int ret; + + ret = kfifo_alloc(&test, FIFO_SIZE, GFP_KERNEL); + if (ret) { + printk(KERN_ERR "error kfifo_alloc\n"); + return ret; + } +#else + INIT_KFIFO(test); +#endif + testfunc(); + + if (proc_create(PROC_FIFO, 0, NULL, &fifo_fops) == NULL) { +#ifdef DYNAMIC + kfifo_free(&test); +#endif + return -ENOMEM; + } + return 0; +} + +static void __exit example_exit(void) +{ + remove_proc_entry(PROC_FIFO, NULL); +#ifdef DYNAMIC + kfifo_free(&test); +#endif +} + +module_init(example_init); +module_exit(example_exit); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Stefani Seibold <stefani@seibold.net>"); |