diff options
Diffstat (limited to 'sys')
| -rw-r--r-- | sys/include/sys/device.h | 54 | ||||
| -rw-r--r-- | sys/kern/kern_device.c | 143 |
2 files changed, 197 insertions, 0 deletions
diff --git a/sys/include/sys/device.h b/sys/include/sys/device.h new file mode 100644 index 0000000..3ba7141 --- /dev/null +++ b/sys/include/sys/device.h @@ -0,0 +1,54 @@ +/* + * 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. + */ + +#ifndef _SYS_DEVICE_H_ +#define _SYS_DEVICE_H_ + +#if defined(_KERNEL) +#include <sys/types.h> +#include <sys/param.h> +#include <sys/queue.h> +#include <sys/proc.h> +#include <sys/sio.h> + +typedef uint8_t devmajor_t; +typedef uint8_t dev_t; + +struct cdevsw { + int(*read)(dev_t dev, struct sio_txn *sio, int flags); +}; + +void *dev_get(devmajor_t major, dev_t dev); +dev_t dev_alloc(devmajor_t major); + +devmajor_t dev_alloc_major(void); +int dev_register(devmajor_t major, dev_t dev, void *devsw); + +#endif /* _KERNEL */ +#endif /* !_SYS_DEVICE_H_ */ diff --git a/sys/kern/kern_device.c b/sys/kern/kern_device.c new file mode 100644 index 0000000..9ea96fe --- /dev/null +++ b/sys/kern/kern_device.c @@ -0,0 +1,143 @@ +/* + * 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 <sys/device.h> +#include <sys/types.h> +#include <sys/errno.h> +#include <vm/dynalloc.h> +#include <string.h> + +#define MAX_MAJOR 256 +#define MAX_MINOR 256 + +struct device_major { + void **devsw_tab; + uint16_t devsw_count; +}; + +static struct device_major devtab[MAX_MAJOR]; + +/* + * Allocate a device major. + * + * Returns 0 on failure. + */ +devmajor_t +dev_alloc_major(void) +{ + static devmajor_t next = 1; + + if (next > MAX_MAJOR) + return 0; + + return next++; +} + +/* + * Allocates a device minor. + * + * @major: Major number for class of device. + * + * Returns 0 on failure. + */ +dev_t +dev_alloc(devmajor_t major) +{ + struct device_major *devmajor; + size_t allocsize; + + if (major >= MAX_MAJOR) + return 0; + + devmajor = &devtab[major]; + if (devmajor->devsw_count >= MAX_MINOR) + return 0; + + /* + * Try to allocate a devsw table if needed. + * + * XXX: If MAX_MINOR is 256 then we'll need roughly 8 * 256 + * (2048) bytes to store each table. Perhaps we should + * figure out a way we can save memory? + */ + if (devmajor->devsw_tab == NULL) { + allocsize = sizeof(void *) * MAX_MINOR; + devmajor->devsw_tab = dynalloc(allocsize); + + if (devmajor->devsw_tab == NULL) + return 0; + + memset(devmajor->devsw_tab, 0, allocsize); + } + + return ++devmajor->devsw_count; +} + +/* + * Register a device. + * + * Returns less than zero value on failure. + */ +int +dev_register(devmajor_t major, dev_t dev, void *devsw) +{ + struct device_major *devmajor; + + if (major >= MAX_MAJOR) + return -EINVAL; + + devmajor = &devtab[major]; + if (dev > devmajor->devsw_count) + return -EINVAL; + + devmajor->devsw_tab[dev] = devsw; + return 0; +} + +/* + * Get a devsw structure from device major + * and minor numbers. + * + * @major: Major number to lookup. + * @dev: Minor number to lookup. + */ +void * +dev_get(devmajor_t major, dev_t dev) +{ + struct device_major *devmajor; + + if (major >= MAX_MAJOR) + return 0; + + devmajor = &devtab[major]; + if (dev > devmajor->devsw_count) + return NULL; + + return devmajor->devsw_tab[dev]; +} |