+++ /dev/null
-#include "devices/disk.h"
-#include <ctype.h>
-#include <debug.h>
-#include <stdbool.h>
-#include <stdio.h>
-#include "devices/timer.h"
-#include "threads/io.h"
-#include "threads/interrupt.h"
-#include "threads/synch.h"
-
-/* The code in this file is an interface to an ATA (IDE)
- controller. It attempts to comply to [ATA-3]. */
-
-/* ATA command block port addresses. */
-#define reg_data(CHANNEL) ((CHANNEL)->reg_base + 0) /* Data. */
-#define reg_error(CHANNEL) ((CHANNEL)->reg_base + 1) /* Error. */
-#define reg_nsect(CHANNEL) ((CHANNEL)->reg_base + 2) /* Sector Count. */
-#define reg_lbal(CHANNEL) ((CHANNEL)->reg_base + 3) /* LBA 0:7. */
-#define reg_lbam(CHANNEL) ((CHANNEL)->reg_base + 4) /* LBA 15:8. */
-#define reg_lbah(CHANNEL) ((CHANNEL)->reg_base + 5) /* LBA 23:16. */
-#define reg_device(CHANNEL) ((CHANNEL)->reg_base + 6) /* Device/LBA 27:24. */
-#define reg_status(CHANNEL) ((CHANNEL)->reg_base + 7) /* Status (r/o). */
-#define reg_command(CHANNEL) reg_status (CHANNEL) /* Command (w/o). */
-
-/* ATA control block port addresses.
- (If we supported non-legacy ATA controllers this would not be
- flexible enough, but it's fine for what we do.) */
-#define reg_ctl(CHANNEL) ((CHANNEL)->reg_base + 0x206) /* Control (w/o). */
-#define reg_alt_status(CHANNEL) reg_ctl (CHANNEL) /* Alt Status (r/o). */
-
-/* Alternate Status Register bits. */
-#define STA_BSY 0x80 /* Busy. */
-#define STA_DRDY 0x40 /* Device Ready. */
-#define STA_DRQ 0x08 /* Data Request. */
-
-/* Control Register bits. */
-#define CTL_SRST 0x04 /* Software Reset. */
-
-/* Device Register bits. */
-#define DEV_MBS 0xa0 /* Must be set. */
-#define DEV_LBA 0x40 /* Linear based addressing. */
-#define DEV_DEV 0x10 /* Select device: 0=master, 1=slave. */
-
-/* Commands.
- Many more are defined but this is the small subset that we
- use. */
-#define CMD_IDENTIFY_DEVICE 0xec /* IDENTIFY DEVICE. */
-#define CMD_READ_SECTOR_RETRY 0x20 /* READ SECTOR with retries. */
-#define CMD_WRITE_SECTOR_RETRY 0x30 /* WRITE SECTOR with retries. */
-
-/* An ATA device. */
-struct disk
- {
- char name[8]; /* Name, e.g. "hd0:1". */
- struct channel *channel; /* Channel disk is on. */
- int dev_no; /* Device 0 or 1 for master or slave. */
-
- bool is_ata; /* 1=This device is an ATA disk. */
- disk_sector_t capacity; /* Capacity in sectors (if is_ata). */
-
- long long read_cnt; /* Number of sectors read. */
- long long write_cnt; /* Number of sectors written. */
- };
-
-/* An ATA channel (aka controller).
- Each channel can control up to two disks. */
-struct channel
- {
- char name[8]; /* Name, e.g. "hd0". */
- uint16_t reg_base; /* Base I/O port. */
- uint8_t irq; /* Interrupt in use. */
-
- struct lock lock; /* Must acquire to access the controller. */
- bool expecting_interrupt; /* True if an interrupt is expected, false if
- any interrupt would be spurious. */
- struct semaphore completion_wait; /* Up'd by interrupt handler. */
-
- struct disk devices[2]; /* The devices on this channel. */
- };
-
-/* We support the two "legacy" ATA channels found in a standard PC. */
-#define CHANNEL_CNT 2
-static struct channel channels[CHANNEL_CNT];
-
-static void reset_channel (struct channel *);
-static bool check_device_type (struct disk *);
-static void identify_ata_device (struct disk *);
-
-static void select_sector (struct disk *, disk_sector_t);
-static void issue_pio_command (struct channel *, uint8_t command);
-static void input_sector (struct channel *, void *);
-static void output_sector (struct channel *, const void *);
-
-static void wait_until_idle (const struct disk *);
-static bool wait_while_busy (const struct disk *);
-static void select_device (const struct disk *);
-static void select_device_wait (const struct disk *);
-
-static void interrupt_handler (struct intr_frame *);
-
-/* Initialize the disk subsystem and detect disks. */
-void
-disk_init (void)
-{
- size_t chan_no;
-
- for (chan_no = 0; chan_no < CHANNEL_CNT; chan_no++)
- {
- struct channel *c = &channels[chan_no];
- int dev_no;
-
- /* Initialize channel. */
- snprintf (c->name, sizeof c->name, "hd%zu", chan_no);
- switch (chan_no)
- {
- case 0:
- c->reg_base = 0x1f0;
- c->irq = 14 + 0x20;
- break;
- case 1:
- c->reg_base = 0x170;
- c->irq = 15 + 0x20;
- break;
- default:
- NOT_REACHED ();
- }
- lock_init (&c->lock);
- c->expecting_interrupt = false;
- sema_init (&c->completion_wait, 0);
-
- /* Initialize devices. */
- for (dev_no = 0; dev_no < 2; dev_no++)
- {
- struct disk *d = &c->devices[dev_no];
- snprintf (d->name, sizeof d->name, "%s:%d", c->name, dev_no);
- d->channel = c;
- d->dev_no = dev_no;
-
- d->is_ata = false;
- d->capacity = 0;
-
- d->read_cnt = d->write_cnt = 0;
- }
-
- /* Register interrupt handler. */
- intr_register_ext (c->irq, interrupt_handler, c->name);
-
- /* Reset hardware. */
- reset_channel (c);
-
- /* Distinguish ATA hard disks from other devices. */
- if (check_device_type (&c->devices[0]))
- check_device_type (&c->devices[1]);
-
- /* Read hard disk identity information. */
- for (dev_no = 0; dev_no < 2; dev_no++)
- if (c->devices[dev_no].is_ata)
- identify_ata_device (&c->devices[dev_no]);
- }
-}
-
-/* Prints disk statistics. */
-void
-disk_print_stats (void)
-{
- int chan_no;
-
- for (chan_no = 0; chan_no < CHANNEL_CNT; chan_no++)
- {
- int dev_no;
-
- for (dev_no = 0; dev_no < 2; dev_no++)
- {
- struct disk *d = disk_get (chan_no, dev_no);
- if (d != NULL && d->is_ata)
- printf ("%s: %lld reads, %lld writes\n",
- d->name, d->read_cnt, d->write_cnt);
- }
- }
-}
-
-/* Returns the disk numbered DEV_NO--either 0 or 1 for master or
- slave, respectively--within the channel numbered CHAN_NO.
-
- Pintos uses disks this way:
- 0:0 - boot loader, command line args, and operating system kernel
- 0:1 - file system
- 1:0 - scratch
- 1:1 - swap
-*/
-struct disk *
-disk_get (int chan_no, int dev_no)
-{
- ASSERT (dev_no == 0 || dev_no == 1);
-
- if (chan_no < (int) CHANNEL_CNT)
- {
- struct disk *d = &channels[chan_no].devices[dev_no];
- if (d->is_ata)
- return d;
- }
- return NULL;
-}
-
-/* Returns the size of disk D, measured in DISK_SECTOR_SIZE-byte
- sectors. */
-disk_sector_t
-disk_size (struct disk *d)
-{
- ASSERT (d != NULL);
-
- return d->capacity;
-}
-
-/* Reads sector SEC_NO from disk D into BUFFER, which must have
- room for DISK_SECTOR_SIZE bytes.
- Internally synchronizes accesses to disks, so external
- per-disk locking is unneeded. */
-void
-disk_read (struct disk *d, disk_sector_t sec_no, void *buffer)
-{
- struct channel *c;
-
- ASSERT (d != NULL);
- ASSERT (buffer != NULL);
-
- c = d->channel;
- lock_acquire (&c->lock);
- select_sector (d, sec_no);
- issue_pio_command (c, CMD_READ_SECTOR_RETRY);
- sema_down (&c->completion_wait);
- if (!wait_while_busy (d))
- PANIC ("%s: disk read failed, sector=%"PRDSNu, d->name, sec_no);
- input_sector (c, buffer);
- d->read_cnt++;
- lock_release (&c->lock);
-}
-
-/* Write sector SEC_NO to disk D from BUFFER, which must contain
- DISK_SECTOR_SIZE bytes. Returns after the disk has
- acknowledged receiving the data.
- Internally synchronizes accesses to disks, so external
- per-disk locking is unneeded. */
-void
-disk_write (struct disk *d, disk_sector_t sec_no, const void *buffer)
-{
- struct channel *c;
-
- ASSERT (d != NULL);
- ASSERT (buffer != NULL);
-
- c = d->channel;
- lock_acquire (&c->lock);
- select_sector (d, sec_no);
- issue_pio_command (c, CMD_WRITE_SECTOR_RETRY);
- if (!wait_while_busy (d))
- PANIC ("%s: disk write failed, sector=%"PRDSNu, d->name, sec_no);
- output_sector (c, buffer);
- sema_down (&c->completion_wait);
- d->write_cnt++;
- lock_release (&c->lock);
-}
-\f
-/* Disk detection and identification. */
-
-static void print_ata_string (char *string, size_t size);
-
-/* Resets an ATA channel and waits for any devices present on it
- to finish the reset. */
-static void
-reset_channel (struct channel *c)
-{
- bool present[2];
- int dev_no;
-
- /* The ATA reset sequence depends on which devices are present,
- so we start by detecting device presence. */
- for (dev_no = 0; dev_no < 2; dev_no++)
- {
- struct disk *d = &c->devices[dev_no];
-
- select_device (d);
-
- outb (reg_nsect (c), 0x55);
- outb (reg_lbal (c), 0xaa);
-
- outb (reg_nsect (c), 0xaa);
- outb (reg_lbal (c), 0x55);
-
- outb (reg_nsect (c), 0x55);
- outb (reg_lbal (c), 0xaa);
-
- present[dev_no] = (inb (reg_nsect (c)) == 0x55
- && inb (reg_lbal (c)) == 0xaa);
- }
-
- /* Issue soft reset sequence, which selects device 0 as a side effect.
- Also enable interrupts. */
- outb (reg_ctl (c), 0);
- timer_usleep (10);
- outb (reg_ctl (c), CTL_SRST);
- timer_usleep (10);
- outb (reg_ctl (c), 0);
-
- timer_msleep (150);
-
- /* Wait for device 0 to clear BSY. */
- if (present[0])
- {
- select_device (&c->devices[0]);
- wait_while_busy (&c->devices[0]);
- }
-
- /* Wait for device 1 to clear BSY. */
- if (present[1])
- {
- int i;
-
- select_device (&c->devices[1]);
- for (i = 0; i < 3000; i++)
- {
- if (inb (reg_nsect (c)) == 1 && inb (reg_lbal (c)) == 1)
- break;
- timer_msleep (10);
- }
- wait_while_busy (&c->devices[1]);
- }
-}
-
-/* Checks whether device D is an ATA disk and sets D's is_ata
- member appropriately. If D is device 0 (master), returns true
- if it's possible that a slave (device 1) exists on this
- channel. If D is device 1 (slave), the return value is not
- meaningful. */
-static bool
-check_device_type (struct disk *d)
-{
- struct channel *c = d->channel;
- uint8_t error, lbam, lbah, status;
-
- select_device (d);
-
- error = inb (reg_error (c));
- lbam = inb (reg_lbam (c));
- lbah = inb (reg_lbah (c));
- status = inb (reg_status (c));
-
- if ((error != 1 && (error != 0x81 || d->dev_no == 1))
- || (status & STA_DRDY) == 0
- || (status & STA_BSY) != 0)
- {
- d->is_ata = false;
- return error != 0x81;
- }
- else
- {
- d->is_ata = (lbam == 0 && lbah == 0) || (lbam == 0x3c && lbah == 0xc3);
- return true;
- }
-}
-
-/* Sends an IDENTIFY DEVICE command to disk D and reads the
- response. Initializes D's capacity member based on the result
- and prints a message describing the disk to the console. */
-static void
-identify_ata_device (struct disk *d)
-{
- struct channel *c = d->channel;
- uint16_t id[DISK_SECTOR_SIZE / 2];
-
- ASSERT (d->is_ata);
-
- /* Send the IDENTIFY DEVICE command, wait for an interrupt
- indicating the device's response is ready, and read the data
- into our buffer. */
- select_device_wait (d);
- issue_pio_command (c, CMD_IDENTIFY_DEVICE);
- sema_down (&c->completion_wait);
- if (!wait_while_busy (d))
- {
- d->is_ata = false;
- return;
- }
- input_sector (c, id);
-
- /* Calculate capacity. */
- d->capacity = id[60] | ((uint32_t) id[61] << 16);
-
- /* Print identification message. */
- printf ("%s: detected %'"PRDSNu" sector (", d->name, d->capacity);
- if (d->capacity > 1024 / DISK_SECTOR_SIZE * 1024 * 1024)
- printf ("%"PRDSNu" GB",
- d->capacity / (1024 / DISK_SECTOR_SIZE * 1024 * 1024));
- else if (d->capacity > 1024 / DISK_SECTOR_SIZE * 1024)
- printf ("%"PRDSNu" MB", d->capacity / (1024 / DISK_SECTOR_SIZE * 1024));
- else if (d->capacity > 1024 / DISK_SECTOR_SIZE)
- printf ("%"PRDSNu" kB", d->capacity / (1024 / DISK_SECTOR_SIZE));
- else
- printf ("%"PRDSNu" byte", d->capacity * DISK_SECTOR_SIZE);
- printf (") disk, model \"");
- print_ata_string ((char *) &id[27], 40);
- printf ("\", serial \"");
- print_ata_string ((char *) &id[10], 20);
- printf ("\"\n");
-}
-
-/* Prints STRING, which consists of SIZE bytes in a funky format:
- each pair of bytes is in reverse order. Does not print
- trailing whitespace and/or nulls. */
-static void
-print_ata_string (char *string, size_t size)
-{
- size_t i;
-
- /* Find the last non-white, non-null character. */
- for (; size > 0; size--)
- {
- int c = string[(size - 1) ^ 1];
- if (c != '\0' && !isspace (c))
- break;
- }
-
- /* Print. */
- for (i = 0; i < size; i++)
- printf ("%c", string[i ^ 1]);
-}
-\f
-/* Selects device D, waiting for it to become ready, and then
- writes SEC_NO to the disk's sector selection registers. (We
- use LBA mode.) */
-static void
-select_sector (struct disk *d, disk_sector_t sec_no)
-{
- struct channel *c = d->channel;
-
- ASSERT (sec_no < d->capacity);
- ASSERT (sec_no < (1UL << 28));
-
- select_device_wait (d);
- outb (reg_nsect (c), 1);
- outb (reg_lbal (c), sec_no);
- outb (reg_lbam (c), sec_no >> 8);
- outb (reg_lbah (c), (sec_no >> 16));
- outb (reg_device (c),
- DEV_MBS | DEV_LBA | (d->dev_no == 1 ? DEV_DEV : 0) | (sec_no >> 24));
-}
-
-/* Writes COMMAND to channel C and prepares for receiving a
- completion interrupt. */
-static void
-issue_pio_command (struct channel *c, uint8_t command)
-{
- /* Interrupts must be enabled or our semaphore will never be
- up'd by the completion handler. */
- ASSERT (intr_get_level () == INTR_ON);
-
- c->expecting_interrupt = true;
- outb (reg_command (c), command);
-}
-
-/* Reads a sector from channel C's data register in PIO mode into
- SECTOR, which must have room for DISK_SECTOR_SIZE bytes. */
-static void
-input_sector (struct channel *c, void *sector)
-{
- insw (reg_data (c), sector, DISK_SECTOR_SIZE / 2);
-}
-
-/* Writes SECTOR to channel C's data register in PIO mode.
- SECTOR must contain DISK_SECTOR_SIZE bytes. */
-static void
-output_sector (struct channel *c, const void *sector)
-{
- outsw (reg_data (c), sector, DISK_SECTOR_SIZE / 2);
-}
-\f
-/* Low-level ATA primitives. */
-
-/* Wait up to 10 seconds for the controller to become idle, that
- is, for the BSY and DRQ bits to clear in the status register.
-
- As a side effect, reading the status register clears any
- pending interrupt. */
-static void
-wait_until_idle (const struct disk *d)
-{
- int i;
-
- for (i = 0; i < 1000; i++)
- {
- if ((inb (reg_status (d->channel)) & (STA_BSY | STA_DRQ)) == 0)
- return;
- timer_usleep (10);
- }
-
- printf ("%s: idle timeout\n", d->name);
-}
-
-/* Wait up to 30 seconds for disk D to clear BSY,
- and then return the status of the DRQ bit.
- The ATA standards say that a disk may take as long as that to
- complete its reset. */
-static bool
-wait_while_busy (const struct disk *d)
-{
- struct channel *c = d->channel;
- int i;
-
- for (i = 0; i < 3000; i++)
- {
- if (i == 700)
- printf ("%s: busy, waiting...", d->name);
- if (!(inb (reg_alt_status (c)) & STA_BSY))
- {
- if (i >= 700)
- printf ("ok\n");
- return (inb (reg_alt_status (c)) & STA_DRQ) != 0;
- }
- timer_msleep (10);
- }
-
- printf ("failed\n");
- return false;
-}
-
-/* Program D's channel so that D is now the selected disk. */
-static void
-select_device (const struct disk *d)
-{
- struct channel *c = d->channel;
- uint8_t dev = DEV_MBS;
- if (d->dev_no == 1)
- dev |= DEV_DEV;
- outb (reg_device (c), dev);
- inb (reg_alt_status (c));
- timer_nsleep (400);
-}
-
-/* Select disk D in its channel, as select_device(), but wait for
- the channel to become idle before and after. */
-static void
-select_device_wait (const struct disk *d)
-{
- wait_until_idle (d);
- select_device (d);
- wait_until_idle (d);
-}
-\f
-/* ATA interrupt handler. */
-static void
-interrupt_handler (struct intr_frame *f)
-{
- struct channel *c;
-
- for (c = channels; c < channels + CHANNEL_CNT; c++)
- if (f->vec_no == c->irq)
- {
- if (c->expecting_interrupt)
- {
- inb (reg_status (c)); /* Acknowledge interrupt. */
- sema_up (&c->completion_wait); /* Wake up waiter. */
- }
- else
- printf ("%s: unexpected interrupt\n", c->name);
- return;
- }
-
- NOT_REACHED ();
-}
-
-
projects / pintos-anon / blobdiff