source: trunk/kernel/fs/devfs/devfs_file.c @ 6

/*
 * devfs/devfs_file.c - devfs file related operations
 *
 * Copyright (c) 2008,2009,2010,2011,2012 Ghassan Almaless
 * Copyright (c) 2011,2012 UPMC Sorbonne Universites
 *
 * This file is part of ALMOS-kernel.
 *
 * ALMOS-kernel is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2.0 of the License.
 *
 * ALMOS-kernel is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with ALMOS-kernel; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include <config.h>
#include <device.h>
#include <driver.h>
#include <kmem.h>
#include <string.h>
#include <vfs.h>
#include <errno.h>
#include <metafs.h>
#include <thread.h>

#include <devfs.h>
#include <devfs-private.h>


KMEM_OBJATTR_INIT(devfs_kmem_file_init)
{
        attr->type   = KMEM_DEVFS_FILE;
        attr->name   = "KCM DevFs File";
        attr->size   = sizeof(struct devfs_file_s);
        attr->aligne = 0;
        attr->min    = CONFIG_DEVFS_FILE_MIN;
        attr->max    = CONFIG_DEVFS_FILE_MAX;
        attr->ctor   = NULL;
        attr->dtor   = NULL;
        return 0;
}

VFS_OPEN_FILE(devfs_open)
{
        register error_t err;
        register struct devfs_context_s *ctx;
        register struct devfs_file_s *info;
        register struct device_s *dev;
        struct vfs_inode_s *inode;
        dev_request_t rq;
        kmem_req_t req;

        inode = file->fr_inode;

        info = file->fr_pv;
        ctx  = (struct devfs_context_s *)&inode->i_ctx->ctx_devfs;

        if(!(inode->i_attr & VFS_DIR))
        {
                dev = (struct device_s*)inode->i_pv;
    
                if(dev->type == DEV_INTERNAL)
                        return EPERM;

                if(dev->type == DEV_BLK)
                        VFS_SET(inode->i_attr,VFS_DEV_BLK);
                else
                        VFS_SET(inode->i_attr,VFS_DEV_CHR);
 
                if(dev->op.dev.open != NULL)
                {
                        rq.fremote = file;
                        if((err=dev->op.dev.open(dev, &rq)))
                                return err;
                }

                priv->dev = (void*)dev;

                return 0;
        }

        if(info == NULL)
        {
                req.type  = KMEM_DEVFS_FILE;
                req.size  = sizeof(*info);
                req.flags = AF_KERNEL;
                info      = kmem_alloc(&req);
        }

        if(info == NULL) return ENOMEM;

        metafs_iter_init(&devfs_db.root, &info->iter);
        info->ctx  = ctx;
        file->fr_pv = info;
  
        metafs_print(&devfs_db.root);
        return 0;
}

#define TMP_BUFF_SZ 512
//FIXME:
//add a "while" loop for the case where the
//buffer TMP_BUFF_SZ is smaller than
//buffer->size
VFS_READ_FILE(devfs_read)
{
        register struct device_s *dev;
        dev_request_t rq;
        uint_t count;
        uint8_t buff[TMP_BUFF_SZ];

        dev = (struct device_s*)file->f_private.dev;

        rq.dst   = &buff[0];
        rq.count = TMP_BUFF_SZ;
        rq.flags = 0;
        rq.file  = file;

        if((count = dev->op.dev.read(dev, &rq)) < 0)
                return count;

        buffer->scpy_to_buff(buffer, &buff[0], count);
        return count;
}

//FIXME: To improve this an avoid the extra copy,
//we could set along with the buffer(src and dest) 
//the functions to manipulate them, such as in 
//do_exec.c
VFS_WRITE_FILE(devfs_write)
{
        register struct device_s *dev;
        uint8_t buff[TMP_BUFF_SZ];
        dev_request_t rq;
        
        dev = (struct device_s*)file->f_private.dev;
        
        //FIXME avoid the extra copy ?
        buffer->scpy_from_buff(buffer, (void*)&buff[0], TMP_BUFF_SZ);
        rq.src   = (void*)&buff[0];
        rq.count = buffer->size;
        rq.flags = 0;
        rq.file  = file;
  
        return dev->op.dev.write(dev, &rq);
}

VFS_LSEEK_FILE(devfs_lseek)
{
        register struct device_s *dev;
        dev_request_t rq;

        dev = (struct device_s*)file->fr_inode->i_pv;

        if(dev->op.dev.lseek == NULL)
                return VFS_ENOTUSED;
  
        rq.fremote = file;
        return dev->op.dev.lseek(dev, &rq);
}

VFS_CLOSE_FILE(devfs_close)
{
        register struct device_s *dev;
        dev_request_t rq;

        if(file->fr_inode->i_attr & VFS_DIR)
                return 0;

        dev = (struct device_s*)file->fr_inode->i_pv;

        if(dev->op.dev.close == NULL)
                return 0;
  
        rq.fremote = file;
        return dev->op.dev.close(dev, &rq);
}

VFS_RELEASE_FILE(devfs_release)
{  
        kmem_req_t req;

        if(file->fr_pv == NULL) 
                return 0;
  
        req.type = KMEM_DEVFS_FILE;
        req.ptr  = file->fr_pv;
        kmem_free(&req);

        file->fr_pv = NULL;
        return 0;
}

VFS_READ_DIR(devfs_readdir)
{
        register struct devfs_file_s *info;
        register struct metafs_s *current;
        register struct device_s *current_dev;
  
        info = file->fr_pv;
  
        if(file->fr_pv == NULL)
                return ENOTDIR;

        if((current = metafs_lookup_next(&devfs_db.root, &info->iter)) == NULL)
                return EEODIR;

        current_dev    = metafs_container(current, struct device_s, node);
        dirent->u_attr = (current_dev->type == DEV_BLK) ? VFS_DEV_BLK : VFS_DEV_CHR;

        strcpy((char*)dirent->u_name, metafs_get_name(current));

        dirent->u_ino = (uint_t) current_dev->base_paddr;

        return 0;
}

VFS_MMAP_FILE(devfs_mmap)
{
        register struct device_s *dev;
        dev_request_t rq;
  
        dev = (struct device_s*)file->f_private.dev;

        if(dev->op.dev.mmap == NULL)
                return ENODEV;

        rq.flags  = 0;
        rq.file   = file;
        rq.region = region;

        return dev->op.dev.mmap(dev, &rq);
}

VFS_MMAP_FILE(devfs_munmap)
{
        register struct device_s *dev;
        dev_request_t rq;

        dev = (struct device_s*)file->f_private.dev;

        if(dev->op.dev.munmap == NULL)
                return ENODEV;

        rq.flags  = 0;
        rq.file   = file;
        rq.region = region;

        return dev->op.dev.munmap(dev, &rq);
}


const struct vfs_file_op_s devfs_f_op = 
{
        .open    = devfs_open,
        .read    = devfs_read,
        .write   = devfs_write,
        .lseek   = devfs_lseek,
        .mmap    = devfs_mmap,
        .munmap  = devfs_munmap,
        .readdir = devfs_readdir,
        .close   = devfs_close,
        .release = devfs_release
};