usr: libc: Add initial disk engine interface

This commit implements a libc interface to the Hyra disk engine and
adds functions such as disk_read() and disk_write(). There is also a
mostly internal __disk_io() routine which is made to have external
linkage as it could potentially be useful for cases where fine grained
control over the engine is needed, though it is recommended to rely on
the other functions whenever possible.

Signed-off-by: Ian Moffett <ian@osmora.org>

1 files changed, 106 insertions, 0 deletions

diff --git a/lib/libc/src/hyra/disk.c b/lib/libc/src/hyra/disk.c
new file mode 100644
index 0000000..354ef03
--- /dev/null
+++ b/lib/libc/src/hyra/disk.c
@@ -0,0 +1,106 @@
+/*
+ * Copyright (c) 2023-2025 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/errno.h>
+#include <sys/syscall.h>
+#include <sys/disk.h>
+
+/*
+ * Disk I/O multiplexer system call which routes
+ * various disk operations via a single call.
+ *
+ * @id: The ID of the disk to be operated on
+ * @op: Operation code
+ * @param: Operation parameters
+ *
+ * Returns the number of bytes operated on upon success,
+ * otherwise a less than zero value is returned.
+ */
+ssize_t
+__disk_io(diskid_t id, diskop_t op, const struct disk_param *param)
+{
+    if (param == NULL) {
+        return -EINVAL;
+    }
+
+    return syscall(
+        SYS_disk,
+        id,
+        op,
+        (uintptr_t)param
+    );
+}
+
+/*
+ * Performs a write operation on a specific disk
+ *
+ * @id: ID of disk to operate on
+ * @blk: Block offset to operate on
+ * @buf: Data to write
+ * @len: Number of bytes to write
+ *
+ * Returns the number of bytes written upon success, otherwise
+ * a less than zero value is returned on error.
+ */
+ssize_t
+disk_write(diskid_t id, blkoff_t blk, const void *buf, size_t len)
+{
+    struct disk_param param;
+
+    if (buf == NULL || len == 0) {
+        return -EINVAL;
+    }
+
+    disk_param_init(buf, blk, len, &param);
+    return __disk_io(id, DISK_IO_WRITE, &param);
+}
+
+/*
+ * Performs a read operation on a specific disk
+ *
+ * @id: ID of disk to operate on
+ * @blk: Block offset to operate on
+ * @buf: Buffer to read data into
+ * @len: Number of bytes to read
+ *
+ * Returns the number of bytes read upon success, otherwise
+ * a less than zero value is returned on error.
+ */
+ssize_t
+disk_read(diskid_t id, blkoff_t blk, void *buf, size_t len)
+{
+    struct disk_param param;
+
+    if (buf == NULL || len == 0) {
+        return -EINVAL;
+    }
+
+    disk_param_init(buf, blk, len, &param);
+    return __disk_io(id, DISK_IO_READ, &param);
+}