vfile.h

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#ifndef _XENO_NUCLEUS_VFILE_H
#define _XENO_NUCLEUS_VFILE_H

#if defined(CONFIG_XENO_OPT_VFILE) || defined(DOXYGEN_CPP)

#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <nucleus/types.h>

struct xnvfile_directory;
struct xnvfile_regular_iterator;
struct xnvfile_snapshot_iterator;
struct xnvfile_lock_ops;

struct xnvfile {
        struct proc_dir_entry *pde;
        struct file *file;
        struct xnvfile_lock_ops *lockops;
        int refcnt;
        void *private;
};

struct xnvfile_lock_ops {
        int (*get)(struct xnvfile *vfile);
        void (*put)(struct xnvfile *vfile);
};

/*
 * XXX: struct semaphore is legacy for mutual exclusion, but supported
 * on both 2.4 and 2.6 kernels. Will be changed to mutex when 2.4
 * support is dropped from Xenomai.
 */
struct xnvfile_hostlock_class {
        struct xnvfile_lock_ops ops;
        struct semaphore sem;
};

struct xnvfile_nklock_class {
        struct xnvfile_lock_ops ops;
        spl_t s;
};

struct xnvfile_input {
        const char __user *u_buf;
        size_t size;
        struct xnvfile *vfile;
};

struct xnvfile_regular_ops {
        int (*rewind)(struct xnvfile_regular_iterator *it);
        void *(*begin)(struct xnvfile_regular_iterator *it);
        void *(*next)(struct xnvfile_regular_iterator *it);
        void (*end)(struct xnvfile_regular_iterator *it);
        int (*show)(struct xnvfile_regular_iterator *it, void *data);
        ssize_t (*store)(struct xnvfile_input *input);
};

struct xnvfile_regular {
        struct xnvfile entry;
        size_t privsz;
        struct xnvfile_regular_ops *ops;
};

struct xnvfile_regular_template {
        size_t privsz;
        struct xnvfile_regular_ops *ops;
        struct xnvfile_lock_ops *lockops;
};

struct xnvfile_regular_iterator {
        loff_t pos;
        struct seq_file *seq;
        struct xnvfile_regular *vfile;
        char private[0];
};

struct xnvfile_snapshot_ops {
        int (*rewind)(struct xnvfile_snapshot_iterator *it);
        void *(*begin)(struct xnvfile_snapshot_iterator *it);
        void (*end)(struct xnvfile_snapshot_iterator *it, void *buf);
        int (*next)(struct xnvfile_snapshot_iterator *it, void *data);
        int (*show)(struct xnvfile_snapshot_iterator *it, void *data);
        ssize_t (*store)(struct xnvfile_input *input);
};

struct xnvfile_rev_tag {
        int rev;
};

struct xnvfile_snapshot_template {
        size_t privsz;
        size_t datasz;
        struct xnvfile_rev_tag *tag;
        struct xnvfile_snapshot_ops *ops;
        struct xnvfile_lock_ops *lockops;
};

struct xnvfile_snapshot {
        struct xnvfile entry;
        size_t privsz;
        size_t datasz;
        struct xnvfile_rev_tag *tag;
        struct xnvfile_snapshot_ops *ops;
};

struct xnvfile_snapshot_iterator {
        int nrdata;
        caddr_t databuf;
        struct seq_file *seq;
        struct xnvfile_snapshot *vfile;
        void (*endfn)(struct xnvfile_snapshot_iterator *it, void *buf);
        char private[0];
};

struct xnvfile_directory {
        struct xnvfile entry;
};

struct xnvfile_link {
        struct xnvfile entry;
};

/* vfile.begin()=> */
#define VFILE_SEQ_EMPTY                 ((void *)-1)
/* =>vfile.show() */
#define VFILE_SEQ_START                 SEQ_START_TOKEN
/* vfile.next/show()=> */
#define VFILE_SEQ_SKIP                  2

#define xnvfile_printf(it, args...)     seq_printf((it)->seq, ##args)
#define xnvfile_write(it, data, len)    seq_write((it)->seq, (data),(len))
#define xnvfile_puts(it, s)             seq_puts((it)->seq, (s))
#define xnvfile_putc(it, c)             seq_putc((it)->seq, (c))

static inline void xnvfile_touch_tag(struct xnvfile_rev_tag *tag)
{
        tag->rev++;
}

static inline void xnvfile_touch(struct xnvfile_snapshot *vfile)
{
        xnvfile_touch_tag(vfile->tag);
}

#define xnvfile_noentry                 \
        {                               \
                .pde = NULL,            \
                .private = NULL,        \
                .file = NULL,           \
                .refcnt = 0,            \
        }

#define xnvfile_nodir   { .entry = xnvfile_noentry }
#define xnvfile_nolink  { .entry = xnvfile_noentry }
#define xnvfile_nofile  { .entry = xnvfile_noentry }

#define xnvfile_priv(e)                 ((e)->entry.private)
#define xnvfile_nref(e)                 ((e)->entry.refcnt)
#define xnvfile_file(e)                 ((e)->entry.file)
#define xnvfile_iterator_priv(it)       ((void *)(&(it)->private))

extern struct xnvfile_nklock_class xnvfile_nucleus_lock;

extern struct xnvfile_directory nkvfroot;

int xnvfile_init_root(void);

void xnvfile_destroy_root(void);

#ifdef __cplusplus
extern "C" {
#endif

int xnvfile_init_snapshot(const char *name,
                          struct xnvfile_snapshot *vfile,
                          struct xnvfile_directory *parent);

int xnvfile_init_regular(const char *name,
                         struct xnvfile_regular *vfile,
                         struct xnvfile_directory *parent);

int xnvfile_init_dir(const char *name,
                     struct xnvfile_directory *vdir,
                     struct xnvfile_directory *parent);

int xnvfile_init_link(const char *from,
                      const char *to,
                      struct xnvfile_link *vlink,
                      struct xnvfile_directory *parent);

void xnvfile_destroy(struct xnvfile *vfile);

ssize_t xnvfile_get_blob(struct xnvfile_input *input,
                         void *data, size_t size);

ssize_t xnvfile_get_string(struct xnvfile_input *input,
                           char *s, size_t maxlen);

ssize_t xnvfile_get_integer(struct xnvfile_input *input, long *valp);

int __vfile_hostlock_get(struct xnvfile *vfile);

void __vfile_hostlock_put(struct xnvfile *vfile);

#ifdef __cplusplus
}
#endif

static inline
void xnvfile_destroy_snapshot(struct xnvfile_snapshot *vfile)
{
        xnvfile_destroy(&vfile->entry);
}

static inline
void xnvfile_destroy_regular(struct xnvfile_regular *vfile)
{
        xnvfile_destroy(&vfile->entry);
}

static inline
void xnvfile_destroy_dir(struct xnvfile_directory *vdir)
{
        xnvfile_destroy(&vdir->entry);
}

static inline
void xnvfile_destroy_link(struct xnvfile_link *vlink)
{
        xnvfile_destroy(&vlink->entry);
}

#define DEFINE_VFILE_HOSTLOCK(name)                                     \
        struct xnvfile_hostlock_class name = {                          \
                .ops = {                                                \
                        .get = __vfile_hostlock_get,                    \
                        .put = __vfile_hostlock_put,                    \
                },                                                      \
                .sem = __SEMAPHORE_INITIALIZER(name.sem, 1),            \
        }

#else /* !CONFIG_XENO_OPT_VFILE */

#define xnvfile_touch_tag(tag)  do { } while (0)

#define xnvfile_touch(vfile)    do { } while (0)

#endif /* !CONFIG_XENO_OPT_VFILE */

#endif /* !_XENO_NUCLEUS_VFILE_H */