188 lines
3.5 KiB
C
188 lines
3.5 KiB
C
/*
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* Minimal PIO-based (non-interrupt-driven) IDE driver code.
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* For information about what all this IDE/ATA magic means,
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* see the materials available on the class references page.
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*/
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#include "types.h"
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#include "param.h"
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#include "mmu.h"
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#include "proc.h"
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#include "defs.h"
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#include "x86.h"
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#include "spinlock.h"
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#define IDE_BSY 0x80
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#define IDE_DRDY 0x40
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#define IDE_DF 0x20
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#define IDE_ERR 0x01
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struct ide_request {
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int diskno;
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uint secno;
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void *addr;
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uint nsecs;
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uint read;
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};
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struct ide_request request[NREQUEST];
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int head, tail;
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struct spinlock ide_lock;
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int disk_channel;
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static int
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ide_wait_ready(int check_error)
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{
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int r;
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while (((r = inb(0x1F7)) & (IDE_BSY|IDE_DRDY)) != IDE_DRDY)
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/* do nothing */;
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if (check_error && (r & (IDE_DF|IDE_ERR)) != 0)
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return -1;
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return 0;
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}
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void
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ide_init(void)
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{
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initlock(&ide_lock, "ide");
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if (ncpu < 2) {
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panic ("ide_init: disk interrupt is going to the second cpu\n");
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}
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ioapic_enable (IRQ_IDE, 1);
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ide_wait_ready(0);
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}
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void
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ide_intr(void)
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{
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acquire(&ide_lock);
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wakeup(&request[tail]);
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release(&ide_lock);
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}
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int
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ide_probe_disk1(void)
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{
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int r, x;
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// wait for Device 0 to be ready
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ide_wait_ready(0);
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// switch to Device 1
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outb(0x1F6, 0xE0 | (1<<4));
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// check for Device 1 to be ready for a while
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for (x = 0; x < 1000 && (r = inb(0x1F7)) == 0; x++)
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/* do nothing */;
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// switch back to Device 0
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outb(0x1F6, 0xE0 | (0<<4));
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cprintf("Device 1 presence: %d\n", (x < 1000));
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return (x < 1000);
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}
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void
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ide_start_request (void)
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{
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struct ide_request *r;
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if (head != tail) {
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r = &request[tail];
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ide_wait_ready(0);
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outb(0x3f6, 0); // generate interrupt
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outb(0x1F2, r->nsecs);
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outb(0x1F3, r->secno & 0xFF);
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outb(0x1F4, (r->secno >> 8) & 0xFF);
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outb(0x1F5, (r->secno >> 16) & 0xFF);
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outb(0x1F6, 0xE0 | ((r->diskno&1)<<4) | ((r->secno>>24)&0x0F));
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if (r->read) outb(0x1F7, 0x20); // read
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else {
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outb(0x1F7, 0x30); // write
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outsl(0x1F0, r->addr, 512/4);
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}
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}
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}
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void *
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ide_start_rw(int diskno, uint secno, void *addr, uint nsecs, int read)
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{
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struct ide_request *r;
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if(!holding(&ide_lock))
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panic("ide_start_read: not holding ide_lock");
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if(nsecs > 1)
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panic("ide_start_read: nsecs too large");
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while ((head + 1) % NREQUEST == tail)
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sleep (&disk_channel, &ide_lock);
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r = &request[head];
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r->secno = secno;
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r->addr = addr;
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r->nsecs = nsecs;
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r->diskno = diskno;
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r->read = read;
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head = (head + 1) % NREQUEST;
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ide_start_request();
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return r;
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}
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int
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ide_finish(void *c)
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{
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int r;
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struct ide_request *req = (struct ide_request *) c;
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if(c != &request[tail])
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panic("ide_finish_read");
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if(!holding(&ide_lock))
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panic("ide_start_read: not holding ide_lock");
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if (req->read) {
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if ((r = ide_wait_ready(1)) >= 0)
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insl(0x1F0, req->addr, 512/4);
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}
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if ((head + 1) % NREQUEST == tail) {
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wakeup(&disk_channel);
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}
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tail = (tail + 1) % NREQUEST;
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ide_start_request();
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return 0;
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}
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int
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ide_write(int diskno, uint secno, const void *src, uint nsecs)
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{
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int r;
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if(nsecs > 256)
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panic("ide_write");
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ide_wait_ready(0);
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outb(0x1F2, nsecs);
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outb(0x1F3, secno & 0xFF);
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outb(0x1F4, (secno >> 8) & 0xFF);
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outb(0x1F5, (secno >> 16) & 0xFF);
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outb(0x1F6, 0xE0 | ((diskno&1)<<4) | ((secno>>24)&0x0F));
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outb(0x1F7, 0x30); // CMD 0x30 means write sector
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for (; nsecs > 0; nsecs--, src += 512) {
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if ((r = ide_wait_ready(1)) < 0)
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return r;
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outsl(0x1F0, src, 512/4);
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}
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return 0;
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}
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