source: mainline/uspace/lib/c/generic/io/kio.c

/*
 * Copyright (c) 2006 Josef Cejka
 * Copyright (c) 2006 Jakub Vana
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup libc
 * @{
 */
/** @file
 */

#include <abi/syscall.h>
#include <stddef.h>
#include <libc.h>
#include <str.h>
#include <stdint.h>
#include <stdlib.h>
#include <errno.h>
#include <abi/kio.h>
#include <io/kio.h>
#include <printf_core.h>
#include <macros.h>
#include <libarch/config.h>

#include "../private/futex.h"

#define KIO_BUFFER_SIZE PAGE_SIZE

static struct {
        futex_t futex;
        char data[KIO_BUFFER_SIZE];
        size_t used;
} kio_buffer;

void __kio_init(void)
{
        if (futex_initialize(&kio_buffer.futex, 1) != EOK)
                abort();
}

void __kio_fini(void)
{
        futex_destroy(&kio_buffer.futex);
}

errno_t kio_write(const void *buf, size_t size, size_t *nwritten)
{
        /* Using down/up instead of lock/unlock so we can print very early. */
        futex_down(&kio_buffer.futex);

        const char *s = buf;
        while (true) {
                const char *endl = memchr(s, '\n', size);
                if (endl) {
                        size_t used = kio_buffer.used;

                        size_t sz = min(KIO_BUFFER_SIZE - used, (size_t) (endl - s));
                        memcpy(&kio_buffer.data[used], s, sz);

                        __SYSCALL3(SYS_KIO, KIO_WRITE,
                            (sysarg_t) &kio_buffer.data[0], used + sz);

                        kio_buffer.used = 0;
                        size -= endl + 1 - s;
                        s = endl + 1;
                } else {
                        size_t used = kio_buffer.used;
                        size_t sz = min(KIO_BUFFER_SIZE - used, size);
                        memcpy(&kio_buffer.data[used], s, sz);
                        kio_buffer.used += sz;
                        break;
                }
        }

        futex_up(&kio_buffer.futex);
        if (nwritten)
                *nwritten = size;
        return EOK;
}

void kio_update(void)
{
        (void) __SYSCALL3(SYS_KIO, KIO_UPDATE, (uintptr_t) NULL, 0);
}

void kio_command(const void *buf, size_t size)
{
        (void) __SYSCALL3(SYS_KIO, KIO_COMMAND, (sysarg_t) buf, (sysarg_t) size);
}

size_t kio_read(char *buf, size_t n, size_t at)
{
        return __SYSCALL3(SYS_KIO_READ, (sysarg_t) buf, n, at);
}

/** Print formatted text to kio.
 *
 * @param fmt Format string
 *
 * \see For more details about format string see printf_core.
 *
 */
int kio_printf(const char *fmt, ...)
{
        va_list args;
        va_start(args, fmt);

        int ret = kio_vprintf(fmt, args);

        va_end(args);

        return ret;
}

static errno_t kio_vprintf_str_write(const char *str, size_t size, void *data)
{
        size_t wr = 0;
        return kio_write(str, size, &wr);
}

/** Print formatted text to kio.
 *
 * @param fmt Format string
 * @param ap  Format parameters
 *
 * \see For more details about format string see printf_core.
 *
 */
int kio_vprintf(const char *fmt, va_list ap)
{
        printf_spec_t ps = {
                kio_vprintf_str_write,
                NULL
        };

        return printf_core(fmt, &ps, ap);
}

/** @}
 */