update name of code to labcodes

labcodes/lab8/kern/fs/devs/dev_disk0.c

@@ -0,0 +1,144 @@
+#include <defs.h>
+#include <mmu.h>
+#include <sem.h>
+#include <ide.h>
+#include <inode.h>
+#include <kmalloc.h>
+#include <dev.h>
+#include <vfs.h>
+#include <iobuf.h>
+#include <error.h>
+#include <assert.h>
+
+#define DISK0_BLKSIZE                   PGSIZE
+#define DISK0_BUFSIZE                   (4 * DISK0_BLKSIZE)
+#define DISK0_BLK_NSECT                 (DISK0_BLKSIZE / SECTSIZE)
+
+static char *disk0_buffer;
+static semaphore_t disk0_sem;
+
+static void
+lock_disk0(void) {
+    down(&(disk0_sem));
+}
+
+static void
+unlock_disk0(void) {
+    up(&(disk0_sem));
+}
+
+static int
+disk0_open(struct device *dev, uint32_t open_flags) {
+    return 0;
+}
+
+static int
+disk0_close(struct device *dev) {
+    return 0;
+}
+
+static void
+disk0_read_blks_nolock(uint32_t blkno, uint32_t nblks) {
+    int ret;
+    uint32_t sectno = blkno * DISK0_BLK_NSECT, nsecs = nblks * DISK0_BLK_NSECT;
+    if ((ret = ide_read_secs(DISK0_DEV_NO, sectno, disk0_buffer, nsecs)) != 0) {
+        panic("disk0: read blkno = %d (sectno = %d), nblks = %d (nsecs = %d): 0x%08x.\n",
+                blkno, sectno, nblks, nsecs, ret);
+    }
+}
+
+static void
+disk0_write_blks_nolock(uint32_t blkno, uint32_t nblks) {
+    int ret;
+    uint32_t sectno = blkno * DISK0_BLK_NSECT, nsecs = nblks * DISK0_BLK_NSECT;
+    if ((ret = ide_write_secs(DISK0_DEV_NO, sectno, disk0_buffer, nsecs)) != 0) {
+        panic("disk0: write blkno = %d (sectno = %d), nblks = %d (nsecs = %d): 0x%08x.\n",
+                blkno, sectno, nblks, nsecs, ret);
+    }
+}
+
+static int
+disk0_io(struct device *dev, struct iobuf *iob, bool write) {
+    off_t offset = iob->io_offset;
+    size_t resid = iob->io_resid;
+    uint32_t blkno = offset / DISK0_BLKSIZE;
+    uint32_t nblks = resid / DISK0_BLKSIZE;
+
+    /* don't allow I/O that isn't block-aligned */
+    if ((offset % DISK0_BLKSIZE) != 0 || (resid % DISK0_BLKSIZE) != 0) {
+        return -E_INVAL;
+    }
+
+    /* don't allow I/O past the end of disk0 */
+    if (blkno + nblks > dev->d_blocks) {
+        return -E_INVAL;
+    }
+
+    /* read/write nothing ? */
+    if (nblks == 0) {
+        return 0;
+    }
+
+    lock_disk0();
+    while (resid != 0) {
+        size_t copied, alen = DISK0_BUFSIZE;
+        if (write) {
+            iobuf_move(iob, disk0_buffer, alen, 0, &copied);
+            assert(copied != 0 && copied <= resid && copied % DISK0_BLKSIZE == 0);
+            nblks = copied / DISK0_BLKSIZE;
+            disk0_write_blks_nolock(blkno, nblks);
+        }
+        else {
+            if (alen > resid) {
+                alen = resid;
+            }
+            nblks = alen / DISK0_BLKSIZE;
+            disk0_read_blks_nolock(blkno, nblks);
+            iobuf_move(iob, disk0_buffer, alen, 1, &copied);
+            assert(copied == alen && copied % DISK0_BLKSIZE == 0);
+        }
+        resid -= copied, blkno += nblks;
+    }
+    unlock_disk0();
+    return 0;
+}
+
+static int
+disk0_ioctl(struct device *dev, int op, void *data) {
+    return -E_UNIMP;
+}
+
+static void
+disk0_device_init(struct device *dev) {
+    static_assert(DISK0_BLKSIZE % SECTSIZE == 0);
+    if (!ide_device_valid(DISK0_DEV_NO)) {
+        panic("disk0 device isn't available.\n");
+    }
+    dev->d_blocks = ide_device_size(DISK0_DEV_NO) / DISK0_BLK_NSECT;
+    dev->d_blocksize = DISK0_BLKSIZE;
+    dev->d_open = disk0_open;
+    dev->d_close = disk0_close;
+    dev->d_io = disk0_io;
+    dev->d_ioctl = disk0_ioctl;
+    sem_init(&(disk0_sem), 1);
+
+    static_assert(DISK0_BUFSIZE % DISK0_BLKSIZE == 0);
+    if ((disk0_buffer = kmalloc(DISK0_BUFSIZE)) == NULL) {
+        panic("disk0 alloc buffer failed.\n");
+    }
+}
+
+void
+dev_init_disk0(void) {
+    struct inode *node;
+    if ((node = dev_create_inode()) == NULL) {
+        panic("disk0: dev_create_node.\n");
+    }
+    disk0_device_init(vop_info(node, device));
+
+    int ret;
+    if ((ret = vfs_add_dev("disk0", node, 1)) != 0) {
+        panic("disk0: vfs_add_dev: %e.\n", ret);
+    }
+}
+