kernel: Introduce disk management framework

This commit introduces the initial Hyra disk management framework. The
goal of this framework is to provide a simplistic API for the management
of storage devices in a way that is more suitable for complex operations.

Upon detection and initialization of a block-based storage medium, the
driver may create a named disk object using the 'disk_add()' function.

Disks that have been registered with the system may be acquired via the
'disk_get_id()' function.

As of the current revision, each disk is given a monotonically incremental
ID for identification and lookups. A disk ID of zero indicates a primary disk
on the system.

Disks may be written to or read from using the 'disk_read()' and 'disk_write()'
functions. Memory buffers used for these operations must be created with the
'disk_buf_alloc()' function and freed with the 'disk_buf_free()' function.

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

1 files changed, 81 insertions, 0 deletions

diff --git a/sys/include/sys/disk.h b/sys/include/sys/disk.h
new file mode 100644
index 0000000..09319f5
--- /dev/null
+++ b/sys/include/sys/disk.h
@@ -0,0 +1,81 @@
+/*
+ * 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.
+ */
+
+#ifndef _SYS_DISK_H_
+#define _SYS_DISK_H_
+
+#include <sys/queue.h>
+#include <sys/device.h>
+#include <sys/types.h>
+#include <sys/limits.h>
+
+#define DISK_PRIMARY 0  /* ID of primary disk */
+
+/*
+ * A disk identifier is a zero-based index into
+ * the disk registry.
+ */
+typedef uint16_t diskid_t;
+
+/*
+ * Block offset / LBA
+ */
+typedef off_t blkoff_t;
+
+/*
+ * Represents a block storage device
+ *
+ * @name: Name of disk
+ * @cookie: Used internally to ensure validity
+ * @bsize: Block size (defaults to 512 bytes)
+ * @dev: Device minor
+ * @id: Disk ID (zero-based index)
+ * @bdev: Block device operations
+ * @link: TAILQ link
+ */
+struct disk {
+    char name[NAME_MAX];
+    uint32_t cookie;
+    uint16_t bsize;
+    dev_t dev;
+    diskid_t id;
+    const struct bdevsw *bdev;
+    TAILQ_ENTRY(disk) link;
+};
+
+void *disk_buf_alloc(diskid_t id, size_t len);
+void disk_buf_free(void *p);
+
+ssize_t disk_read(diskid_t id, blkoff_t blk, void *buf, size_t len);
+ssize_t disk_write(diskid_t id, blkoff_t blk, const void *buf, size_t len);
+
+int disk_add(const char *name, dev_t dev, const struct bdevsw *bdev, int flags);
+int disk_get_id(diskid_t id, struct disk **res);
+
+#endif  /* !_SYS_DISK_H_ */