From 4e2c7c20a17e1264d9dc598e8919f94226fb67e2 Mon Sep 17 00:00:00 2001 From: Ian Moffett Date: Tue, 7 Oct 2025 20:39:08 -0400 Subject: kern: os: Add I/O tap framework The I/O tap framework provides a way to bypass the typical device filesystem interface for applications where more direct access would be beneficial. Signed-off-by: Ian Moffett --- src/sys/include/os/iotap.h | 82 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 82 insertions(+) create mode 100644 src/sys/include/os/iotap.h (limited to 'src/sys/include/os/iotap.h') diff --git a/src/sys/include/os/iotap.h b/src/sys/include/os/iotap.h new file mode 100644 index 0000000..7421bf1 --- /dev/null +++ b/src/sys/include/os/iotap.h @@ -0,0 +1,82 @@ +/* + * Copyright (c) 2025 Ian Marco Moffett and L5 engineers + * 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 the project 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 _OS_IOTAP_H_ +#define _OS_IOTAP_H_ 1 + +#include +#include + +struct iotap_desc; +typedef int16_t iotap_t; + +struct iotap_ops { + ssize_t(*read)(struct iotap_desc *desc, void *p, size_t len); +}; + +/* + * Represents an I/O tap descriptor used to interface + * with a device + * + * @name: I/O tap name + * @id: ID of I/O tap + * @ops: I/O tap operations + * + * XXX: When registering an I/O tap, leave `id' unset as it will + * be filled by the registration logic. + */ +struct iotap_desc { + char *name; + iotap_t id; + struct iotap_ops *ops; +}; + +/* + * Register an I/O tap interface + * + * @iotap: I/O tap interface descriptor to register + * + * Returns an I/O table ID as a handle on success, + * otherwise a less than zero value on failure. + */ +iotap_t iotap_register(const struct iotap_desc *iotap); + +/* + * Look up an I/O tap by name + * + * @name: Name of I/O tap to look up + * @dp_res: I/O tap descriptor result + * + * Returns zero on success with a result + * assigned to `dp`, otherwise a less than + * zero value on failure. + */ +int iotap_lookup(const char *name, struct iotap_desc *dp_res); + +#endif /* !_OS_IOTAP_H_ */ -- cgit v1.2.3