From 190f059455b7057c99cb3b24ca63d5ff0872a562 Mon Sep 17 00:00:00 2001 From: Ian Moffett Date: Wed, 10 Apr 2024 11:24:46 -0400 Subject: kernel: fs: Add devfs Signed-off-by: Ian Moffett --- sys/fs/devfs.c | 208 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 208 insertions(+) create mode 100644 sys/fs/devfs.c (limited to 'sys/fs') diff --git a/sys/fs/devfs.c b/sys/fs/devfs.c new file mode 100644 index 0000000..0438b14 --- /dev/null +++ b/sys/fs/devfs.c @@ -0,0 +1,208 @@ +/* + * Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. 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. + * 3. Neither the name of Hyra nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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 COPYRIGHT OWNER OR CONTRIBUTORS 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. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +struct device_node { + struct spinlock lock; + char *name; + uint8_t is_block : 1; + dev_t major, minor; + TAILQ_ENTRY(device_node) link; +}; + +static TAILQ_HEAD(, device_node) nodes; +static bool nodelist_init = false; + +static struct device_node * +node_from_name(const char *name) +{ + struct device_node *n; + + TAILQ_FOREACH(n, &nodes, link) { + if (strcmp(n->name, name) == 0) { + return n; + } + } + + return NULL; +} + +static int +blkdev_read(struct device *dev, struct device_node *node, struct sio_txn *sio) +{ + char *buf; + struct sio_txn dev_txn = {0}; + size_t buf_size = dev->blocksize * sio->len; + + if (dev->blocksize == 0 || sio->len == 0) { + /* Sizes can't be zero! */ + return -EIO; + } + + spinlock_acquire(&node->lock); + buf = dynalloc_memalign(buf_size, 0x1000); + if (buf == NULL) { + spinlock_release(&node->lock); + return -ENOMEM; + } + + dev_txn.len = __DIV_ROUNDUP(sio->len, 512); + dev_txn.buf = buf; + dev_txn.offset = sio->offset; + dev->read(dev, &dev_txn); + spinlock_release(&node->lock); + + for (size_t i = 0; i < sio->len; ++i) { + ((uint8_t *)sio->buf)[i] = buf[i]; + } + + dynfree(buf); + return sio->len; +} + + +static int +vop_vget(struct vnode *parent, const char *name, struct vnode **vp) +{ + struct device_node *dev; + struct vnode *vnode; + int status, vtype; + + if (!nodelist_init) { + return -EIO; + } + + if ((dev = node_from_name(name)) == NULL) { + return -ENOENT; + } + + vtype = dev->is_block ? VBLK : VCHR; + if ((status = vfs_alloc_vnode(&vnode, NULL, vtype)) != 0) { + return status; + } + + vnode->parent = parent; + vnode->data = dev; + vnode->vops = &g_devfs_vops; + *vp = vnode; + return 0; +} + +static int +vop_read(struct vnode *vp, struct sio_txn *sio) +{ + struct device_node *node; + struct device *dev; + + if (vp == NULL) { + return -EIO; + } + + node = vp->data; + dev = device_fetch(node->major, node->minor); + return blkdev_read(dev, node, sio); +} + +static int +devfs_init(struct fs_info *info) +{ + TAILQ_INIT(&nodes); + nodelist_init = true; + return 0; +} + +static int +devfs_make_devicenode(const char *name, struct device_node **node_out) +{ + size_t name_len = 0; + const char *p = name; + struct device_node *node; + + /* + * Only one filename, no paths. + * + * TODO: Do something better here... */ + for (; *p; ++p, ++name_len) { + if (*p == '/') + return -EINVAL; + } + + /* Ensure this filename has valid chars */ + if (!vfs_is_valid_path(name)) { + return -EINVAL; + } + + node = dynalloc(sizeof(struct device_node)); + if (node == NULL) + return -ENOMEM; + + node->name = dynalloc(sizeof(char) * name_len); + if (node->name == NULL) + return -ENOMEM; + + memcpy(node->name, name, name_len + 1); + *node_out = node; + return 0; +} + +int +devfs_add_blkdev(const char *name, const struct device *blkdev) +{ + struct device_node *node; + int status; + + if ((status = devfs_make_devicenode(name, &node)) != 0) { + return status; + } + + node->major = blkdev->major; + node->minor = blkdev->minor; + node->is_block = 1; + TAILQ_INSERT_HEAD(&nodes, node, link); + return 0; +} + +struct vfsops g_devfs_ops = { + .init = devfs_init +}; + +struct vops g_devfs_vops = { + .vget = vop_vget, + .read = vop_read +}; -- cgit v1.2.3