--- /dev/null
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/atomic.h>
+#include <linux/spinlock.h>
+#include <linux/vmalloc.h>
+#include <linux/cdev.h>
+#include <linux/list.h>
+#include <linux/fs.h>
+#include <asm/uaccess.h>
+#include "buffer.h"
+
+#define BUF_DEBUG
+
+#ifdef BUF_DEBUG
+#define DPRINTF(format, args...) \
+ do { \
+ char *f = strrchr(__FILE__, '/'); \
+ printk("%s[%s:%u:%s]: " format "\n", BUF_DEVICE, f ? f + 1: __FILE__, \
+ __LINE__, __FUNCTION__, ##args); \
+ } while (0)
+#else /* !BUF_DEBUG */
+#define DPRINTF(format, args...)
+#endif /* BUF_DEBUG */
+
+#define EPRINTF(format, args...) \
+ do { \
+ printk("%s: " format "\n", BUF_DEVICE, ##args); \
+ } while (0)
+
+struct chunk {
+ struct list_head list;
+ unsigned long size;
+ void *payload;
+};
+
+struct buffer_device {
+ struct list_head free_chunks;
+ struct list_head used_chunks;
+ spinlock_t lock;
+ struct cdev cdev;
+ dev_t dev;
+ unsigned long size;
+ unsigned long chunk_size;
+ char *buf;
+};
+
+static int buf_open(struct inode *, struct file *);
+static int buf_release(struct inode *, struct file *);
+static int buf_mmap(struct file *, struct vm_area_struct *);
+static ssize_t buf_read(struct file *, char __user *, size_t, loff_t *);
+static ssize_t buf_write(struct file *, const char __user *, size_t, loff_t *);
+static long buf_ioctl(struct file *, unsigned int, unsigned long);
+static unsigned int buf_poll(struct file *, struct poll_table_struct *);
+static ssize_t buf_splice_read(struct file *, loff_t *,
+ struct pipe_inode_info *, size_t, unsigned int);
+static ssize_t buf_splice_write(struct pipe_inode_info *, struct file *,
+ loff_t *, size_t, unsigned int);
+
+static struct file_operations buf_fops = {
+ .owner = THIS_MODULE,
+ .open = buf_open,
+ .release = buf_release,
+ .mmap = buf_mmap,
+ .read = buf_read,
+ .write = buf_write,
+ .unlocked_ioctl = buf_ioctl,
+ .poll = buf_poll,
+ .splice_read = buf_splice_read,
+ .splice_write = buf_splice_write
+};
+
+static struct buffer_device bdevice = {
+ .free_chunks = LIST_HEAD_INIT(bdevice.free_chunks),
+ .used_chunks = LIST_HEAD_INIT(bdevice.used_chunks),
+ .lock = __SPIN_LOCK_UNLOCKED(bdevice.lock),
+ .dev = MKDEV(BUF_DEFAULT_MAJOR, BUF_DEFAULT_MAJOR),
+ .size = 0,
+ .chunk_size = 0,
+ .buf = NULL
+};
+
+/* --- chunks manipulation routines --- */
+static inline void *buf_get_free_chunk(void)
+{
+ if (!list_empty(&bdevice.free_chunks))
+ return list_first_entry(&bdevice.free_chunks, struct chunk, list);
+
+ return NULL;
+}
+
+static inline void *buf_get_used_chunk(void)
+{
+ if (!list_empty(&bdevice.used_chunks))
+ return list_first_entry(&bdevice.used_chunks, struct chunk, list);
+
+ return NULL;
+}
+
+static inline void buf_free_chunk(struct chunk *chunk)
+{
+ list_move_tail(&chunk->list, &bdevice.free_chunks);
+ chunk->size = 0;
+}
+
+static inline void buf_use_chunk(struct chunk *chunk)
+{
+ list_move_tail(&chunk->list, &bdevice.used_chunks);
+ chunk->size = 0;
+}
+
+static inline void buf_check_chunk_size(struct chunk *chunk, unsigned long size)
+{
+ return (bdevice.chunk_size - chunk->size <= size);
+}
+
+static inline unsigned long buf_copy_to_chunk(struct chunk *chunk,
+ const char __user *buf, size_t length)
+{
+ return copy_from_user(chunk->payload, buf, length);
+}
+
+static inline unsigned long buf_copy_from_chunk(struct chunk *chunk,
+ char __user *buf, size_t length)
+{
+ return copy_to_user(buf, chunk->payload, length);
+}
+
+/* --- buffer manipulation routines */
+static inline void *buf_get_chunk(int i)
+{
+ return (((struct chunk *)bdevice.buf) + i); //TODO FIXME!!!!
+}
+
+static int buf_init(unsigned long size, unsigned long chunk_size)
+{
+ int retval = 0;
+
+ INIT_LIST_HEAD(&bdevice.free_chunks);
+ INIT_LIST_HEAD(&bdevice.used_chunks);
+ bdevice.size = 0;
+ bdevice.chunk_size = 0;
+
+ bdevice.buf = vmalloc(size);
+ if (!bdevice.buf) {
+ retval = -ENOMEM;
+ goto out;
+ }
+
+ /*for (;;) { //TODO
+ struct chunk *chunk = buf_get_chunk(i); //TODO
+ list_add_tail(&chunk->list, &bdevice.free_chunks);
+ }*/
+
+out:
+ return retval;
+}
+
+static int buf_free(void)
+{
+ INIT_LIST_HEAD(&bdevice.free_chunks);
+ INIT_LIST_HEAD(&bdevice.used_chunks);
+ bdevice.size = 0;
+ bdevice.chunk_size = 0;
+
+ if (bdevice.buf)
+ vfree(bdevice.buf);
+ bdevice.buf = NULL;
+
+ return 0;
+}
+
+/* --- char dev file operations --- */
+static int buf_open(struct inode *inode, struct file *filp)
+{
+ /*struct buffer_device *dev = NULL; //TODO
+
+ if (filp->f_flags & O_WRONLY) {
+ }
+
+ if ((filp->f_flags & O_ACCMODE) == O_WRONLY) {
+ }
+
+ if (!atomic_dec_and_test()) {
+ //TODO
+ return -EBUSY;
+ }
+
+ filp->private_data = dev;*/
+ DPRINTF("");
+ return 0;
+}
+
+static int buf_release(struct inode *inode, struct file *filp)
+{
+ DPRINTF("");
+ return 0;
+}
+
+static int buf_mmap(struct file *filp, struct vm_area_struct *vma)
+{
+ EPRINTF("mmap() operation is not supported");
+ return -ENODEV;
+}
+
+static ssize_t buf_read(struct file *filp, char __user *buf, size_t length,
+ loff_t *offset)
+{
+ DPRINTF("");
+ return 0;
+}
+
+static ssize_t buf_write(struct file *filp, const char __user *buf,
+ size_t length, loff_t *offset)
+{
+ DPRINTF("");
+ return length;
+}
+
+static long buf_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
+{
+ DPRINTF("");
+ return 0;
+}
+
+static unsigned int buf_poll(struct file *filp, struct poll_table_struct *table)
+{
+ DPRINTF("");
+ return 0;
+}
+
+static ssize_t buf_splice_read(struct file *filp, loff_t *offset,
+ struct pipe_inode_info *pipe, size_t length, unsigned int flags)
+{
+ DPRINTF("");
+ return 0;
+}
+
+static ssize_t buf_splice_write(struct pipe_inode_info *pipe, struct file *filp,
+ loff_t *offset, size_t length, unsigned int flags)
+{
+ DPRINTF("");
+ return 0;
+}
+
+/* --- module init/exit routines --- */
+static int __init buf_module_init(void)
+{
+ int retval = 0;
+
+ bdevice.dev = MKDEV(BUF_DEFAULT_MAJOR, BUF_DEFAULT_MINOR);
+
+ retval = alloc_chrdev_region(&bdevice.dev, BUF_DEFAULT_MINOR,
+ BUF_NUM_DEVICES, BUF_DEVICE);
+ if (retval < 0) {
+ EPRINTF("(%d) - alloc_chrdev_region", retval);
+ goto out;
+ }
+
+ cdev_init(&bdevice.cdev, &buf_fops);
+ bdevice.cdev.owner = THIS_MODULE;
+ bdevice.cdev.ops = &buf_fops;
+
+ retval = cdev_add(&bdevice.cdev, bdevice.dev, BUF_NUM_DEVICES);
+ if (retval < 0) {
+ EPRINTF("(%d) - cdev_add", retval);
+ goto out;
+ }
+
+out:
+ DPRINTF("major = %d", MAJOR(bdevice.dev));
+ return retval;
+}
+
+static void __exit buf_module_exit(void)
+{
+ DPRINTF("major = %d", MAJOR(bdevice.dev));
+ cdev_del(&bdevice.cdev);
+ unregister_chrdev_region(bdevice.dev, BUF_NUM_DEVICES);
+}
+
+module_init(buf_module_init);
+module_exit(buf_module_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("SWAP buffer module");
projects / platform / kernel / swap-modules.git / commitdiff