vfs: Block devices

include/zinnia/blockdev.h

@@ -0,0 +1,148 @@
+// SPDX-License-Identifier: ISC
+
+#pragma once
+
+#include <zinnia/atomic.h>
+#include <zinnia/errno.h>
+#include <zinnia/event.h>
+#include <zinnia/guid.h>
+#include <zinnia/initgraph.h>
+#include <zinnia/types.h>
+#include <zinnia/vfs.h>
+#include <zinnia/vmo.h>
+#include <stddef.h>
+#include <stdint.h>
+
+enum bio_op : uint8_t {
+    BIO_READ,
+    BIO_WRITE,
+    BIO_FLUSH,
+};
+
+struct bio_seg {
+    phys_t addr;
+    size_t len;
+};
+
+struct blockdev;
+
+// A block IO operation.
+struct bio {
+    enum bio_op op;               // What to do.
+    uint64_t lba;                 // Starting block.
+    size_t num_lbas;              // Amount of blocks to read.
+    struct blockdev* dev;         // Device to use for this bio.
+    errno_t status;               // Result of this operation.
+    size_t done_lbas;             // Current progress.
+    void (*end)(struct bio* bio); // Callback which runs when the bio completes.
+    void* priv;                   // Driver data.
+    struct bio* parent;           // For nested bios.
+    uint64_t parent_offset;
+    _Atomic(size_t) pending;
+    _Atomic(uint64_t) short_offset;
+    _Atomic(errno_t) child_status;
+    struct event event; // Event for poll.
+    size_t num_segs;    // Counter for `segs`.
+    struct bio_seg segs[];
+};
+
+struct blockdev_limits {
+    size_t max_lbas;
+    size_t max_segs;
+};
+
+struct blockdev_ops {
+    // Submit a bio for execution on this block device.
+    errno_t (*submit)(struct blockdev* dev, struct bio* bio);
+    // Handles an ioctl for the block device.
+    errno_t (*ioctl)(struct blockdev* dev, struct vfs_file* file, uintptr_t request, uintptr_t arg, uintptr_t* out);
+    void (*destroy)(struct blockdev* dev);
+};
+
+struct blockdev {
+    struct vmo cache;
+    const struct blockdev_ops* ops;
+    dev_t dev;
+    size_t lba_size;
+    uint64_t lba_count;
+    struct blockdev_limits limits;
+    _Atomic(bool) claimed;
+};
+
+struct bio* bio_alloc(enum bio_op op, size_t num_segs);
+
+void bio_free(struct bio* bio);
+
+// Submit a bio to run on `dev`.
+void bio_submit(struct blockdev* dev, struct bio* bio);
+
+void bio_complete(struct bio* bio, errno_t status, size_t done_lbas);
+
+errno_t bio_wait(struct bio* bio, size_t* out_lbas);
+
+void blockdev_init(
+    struct blockdev* dev,
+    const struct blockdev_ops* ops,
+    uint32_t major,
+    uint32_t minor,
+    size_t lba_size,
+    uint64_t lba_count
+);
+void blockdev_ref(struct blockdev* dev);
+void blockdev_unref(struct blockdev* dev);
+
+// Performs IO on a block device using `bio_seg` segments.
+errno_t blockdev_rw(
+    struct blockdev* dev,
+    enum bio_op op,
+    uint64_t lba,
+    size_t num_lbas,
+    const struct bio_seg* segs,
+    size_t num_segs,
+    size_t* out_lbas
+);
+
+// Performs IO on a block device using pages.
+errno_t blockdev_rw_pages(
+    struct blockdev* dev,
+    enum bio_op op,
+    uint64_t lba,
+    size_t num_lbas,
+    struct page** pages,
+    size_t count,
+    size_t* out_lbas
+);
+
+// Flushes out all outstanding bios on `dev`.
+errno_t blockdev_flush(struct blockdev* dev);
+
+errno_t blockdev_from_node(struct vfs_node* node, struct blockdev** out);
+errno_t blockdev_claim(struct blockdev* dev);
+void blockdev_release(struct blockdev* dev);
+
+// Adds a new block device to the list of known devices.
+// Will also add a node in `/dev/block`.
+errno_t blockdev_register(const char* name, struct blockdev* dev);
+
+// Rescans `dev` for partitions or file systems.
+errno_t blockdev_rescan(struct blockdev* dev);
+
+// Syncs all outstanding requests blockdevs
+errno_t blockdev_sync_all();
+
+errno_t devtmpfs_add_blockdev(const char* name, struct blockdev* dev, mode_t mode);
+
+errno_t partition_new(struct blockdev* parent, uint64_t start_lba, uint64_t lba_count, struct blockdev** out);
+
+struct gpt_partition {
+    struct guid type_guid;
+    struct guid unique_guid;
+    uint64_t start_lba;
+    uint64_t end_lba;
+};
+
+errno_t gpt_scan(struct blockdev* dev, struct gpt_partition** out, size_t* out_count);
+
+errno_t ramdisk_new(phys_t base, size_t length, struct blockdev** out);
+
+INIT_EXTERN(block_stage);

include/zinnia/initramfs.h

@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: ISC
+
+#pragma once
+
+#include <zinnia/errno.h>
+#include <zinnia/vfs.h>
+#include <stddef.h>
+
+struct boot_info;
+
+bool initramfs_is_valid(const void* data, size_t len);
+
+errno_t initramfs_load(struct vfs_path root, struct vfs_path target, const void* data, size_t len);
+
+void initramfs_load_boot_modules(struct boot_info* info);