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6d0027c66c
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ba862f2f65
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/*
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* linux/kernel/hd.c
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*
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* (C) 1991 Linus Torvalds
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*/
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/*
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* This is the low-level hd interrupt support. It traverses the
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* request-list, using interrupts to jump between functions. As
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* all the functions are called within interrupts, we may not
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* sleep. Special care is recommended.
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*
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* modified by Drew Eckhardt to check nr of hd's from the CMOS.
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*/
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#include <linux/config.h>
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#include <linux/sched.h>
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#include <linux/fs.h>
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#include <linux/kernel.h>
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#include <linux/hdreg.h>
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#include <asm/system.h>
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#include <asm/io.h>
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#include <asm/segment.h>
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#define MAJOR_NR 3
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#include "blk.h"
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#define CMOS_READ(addr) ({ \
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outb_p(0x80|addr,0x70); \
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inb_p(0x71); \
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})
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/* Max read/write errors/sector */
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#define MAX_ERRORS 7
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#define MAX_HD 2
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static void recal_intr(void);
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static int recalibrate = 0; /* 1, wen */
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static int reset = 0;
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/*
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* This struct defines the HD's and their types.
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*/
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struct hd_i_struct {
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int head,sect,cyl,wpcom,lzone,ctl;
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};
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#ifdef HD_TYPE
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struct hd_i_struct hd_info[] = { HD_TYPE };
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#define NR_HD ((sizeof (hd_info))/(sizeof (struct hd_i_struct)))
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#else
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struct hd_i_struct hd_info[] = { {0,0,0,0,0,0},{0,0,0,0,0,0} };
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static int NR_HD = 0;
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#endif
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static struct hd_struct {
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long start_sect;
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long nr_sects;
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} hd[5*MAX_HD]={{0,0},};
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#define port_read(port,buf,nr) \
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__asm__("cld;rep;insw"::"d" (port),"D" (buf),"c" (nr))
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#define port_write(port,buf,nr) \
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__asm__("cld;rep;outsw"::"d" (port),"S" (buf),"c" (nr))
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extern void hd_interrupt(void);
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extern void rd_load(void);
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/* This may be used only once, enforced by 'static int callable' */
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int sys_setup(void * BIOS)
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{
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static int callable = 1;
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int i,drive;
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unsigned char cmos_disks;
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struct partition *p;
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struct buffer_head * bh;
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if (!callable)
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return -1;
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callable = 0;
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#ifndef HD_TYPE
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for (drive=0 ; drive<2 ; drive++) {
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hd_info[drive].cyl = *(unsigned short *) BIOS;
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hd_info[drive].head = *(unsigned char *) (2+BIOS);
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hd_info[drive].wpcom = *(unsigned short *) (5+BIOS);
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hd_info[drive].ctl = *(unsigned char *) (8+BIOS);
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hd_info[drive].lzone = *(unsigned short *) (12+BIOS);
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hd_info[drive].sect = *(unsigned char *) (14+BIOS);
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BIOS += 16;
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}
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if (hd_info[1].cyl)
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NR_HD=2;
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else
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NR_HD=1;
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#endif
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for (i=0 ; i<NR_HD ; i++) {
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hd[i*5].start_sect = 0;
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hd[i*5].nr_sects = hd_info[i].head*
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hd_info[i].sect*hd_info[i].cyl;
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}
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/*
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We querry CMOS about hard disks : it could be that
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we have a SCSI/ESDI/etc controller that is BIOS
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compatable with ST-506, and thus showing up in our
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BIOS table, but not register compatable, and therefore
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not present in CMOS.
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Furthurmore, we will assume that our ST-506 drives
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<if any> are the primary drives in the system, and
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the ones reflected as drive 1 or 2.
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The first drive is stored in the high nibble of CMOS
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byte 0x12, the second in the low nibble. This will be
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either a 4 bit drive type or 0xf indicating use byte 0x19
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for an 8 bit type, drive 1, 0x1a for drive 2 in CMOS.
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Needless to say, a non-zero value means we have
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an AT controller hard disk for that drive.
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*/
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if ((cmos_disks = CMOS_READ(0x12)) & 0xf0)
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if (cmos_disks & 0x0f)
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NR_HD = 2;
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else
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NR_HD = 1;
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else
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NR_HD = 0;
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for (i = NR_HD ; i < 2 ; i++) {
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hd[i*5].start_sect = 0;
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hd[i*5].nr_sects = 0;
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}
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for (drive=0 ; drive<NR_HD ; drive++) {
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if (!(bh = bread(0x300 + drive*5,0))) {
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printk("Unable to read partition table of drive %d\n\r",
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drive);
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panic("");
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}
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if (bh->b_data[510] != 0x55 || (unsigned char)
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bh->b_data[511] != 0xAA) {
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printk("Bad partition table on drive %d\n\r",drive);
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panic("");
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}
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p = 0x1BE + (void *)bh->b_data;
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for (i=1;i<5;i++,p++) {
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hd[i+5*drive].start_sect = p->start_sect;
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hd[i+5*drive].nr_sects = p->nr_sects;
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}
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brelse(bh);
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}
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if (NR_HD)
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printk("Partition table%s ok.\n\r",(NR_HD>1)?"s":"");
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rd_load();
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mount_root();
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return (0);
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}
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static int controller_ready(void)
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{
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/* int retries=10000; */
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int retries=100000;
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/* while (--retries && (inb_p(HD_STATUS)&0xc0)!=0x40); */
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while (--retries && (inb_p(HD_STATUS)&0x80));
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return (retries);
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}
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static int win_result(void)
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{
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int i=inb_p(HD_STATUS);
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if ((i & (BUSY_STAT | READY_STAT | WRERR_STAT | SEEK_STAT | ERR_STAT))
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== (READY_STAT | SEEK_STAT))
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return(0); /* ok */
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if (i&1) i=inb(HD_ERROR);
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return (1);
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}
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static void hd_out(unsigned int drive,unsigned int nsect,unsigned int sect,
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unsigned int head,unsigned int cyl,unsigned int cmd,
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void (*intr_addr)(void))
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{
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register int port asm("dx");
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if (drive>1 || head>15)
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panic("Trying to write bad sector");
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if (!controller_ready())
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panic("HD controller not ready");
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do_hd = intr_addr;
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outb_p(hd_info[drive].ctl,HD_CMD);
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port=HD_DATA;
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outb_p(hd_info[drive].wpcom>>2,++port);
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outb_p(nsect,++port);
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outb_p(sect,++port);
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outb_p(cyl,++port);
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outb_p(cyl>>8,++port);
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outb_p(0xA0|(drive<<4)|head,++port);
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outb(cmd,++port);
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}
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static int drive_busy(void)
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{
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unsigned int i;
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for (i = 0; i < 10000; i++)
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if (READY_STAT == (inb_p(HD_STATUS) & (BUSY_STAT|READY_STAT)))
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break;
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i = inb(HD_STATUS);
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i &= BUSY_STAT | READY_STAT | SEEK_STAT;
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if (i == READY_STAT | SEEK_STAT)
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return(0);
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printk("HD controller times out\n\r");
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return(1);
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}
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static void reset_controller(void)
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{
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int i;
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outb(4,HD_CMD);
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for(i = 0; i < 100; i++) nop();
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outb(hd_info[0].ctl & 0x0f ,HD_CMD);
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if (drive_busy())
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printk("HD-controller still busy\n\r");
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if ((i = inb(HD_ERROR)) != 1)
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printk("HD-controller reset failed: %02x\n\r",i);
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}
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static void reset_hd(int nr)
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{
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reset_controller();
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hd_out(nr,hd_info[nr].sect,hd_info[nr].sect,hd_info[nr].head-1,
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hd_info[nr].cyl,WIN_SPECIFY,&recal_intr);
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}
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void unexpected_hd_interrupt(void)
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{
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printk("Unexpected HD interrupt\n\r");
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}
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static void bad_rw_intr(void)
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{
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if (++CURRENT->errors >= MAX_ERRORS)
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end_request(0);
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if (CURRENT->errors > MAX_ERRORS/2)
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reset = 1;
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}
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static void read_intr(void)
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{
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if (win_result()) {
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bad_rw_intr();
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do_hd_request();
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return;
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}
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port_read(HD_DATA,CURRENT->buffer,256);
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CURRENT->errors = 0;
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CURRENT->buffer += 512;
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CURRENT->sector++;
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if (--CURRENT->nr_sectors) {
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do_hd = &read_intr;
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return;
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}
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end_request(1);
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do_hd_request();
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}
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static void write_intr(void)
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{
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if (win_result()) {
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bad_rw_intr();
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do_hd_request();
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return;
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}
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if (--CURRENT->nr_sectors) {
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CURRENT->sector++;
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CURRENT->buffer += 512;
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do_hd = &write_intr;
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port_write(HD_DATA,CURRENT->buffer,256);
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return;
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}
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end_request(1);
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do_hd_request();
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}
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static void recal_intr(void)
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{
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if (win_result())
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bad_rw_intr();
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do_hd_request();
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}
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void do_hd_request(void)
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{
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int i,r;
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unsigned int block,dev;
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unsigned int sec,head,cyl;
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unsigned int nsect;
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INIT_REQUEST;
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dev = MINOR(CURRENT->dev);
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block = CURRENT->sector;
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if (dev >= 5*NR_HD || block+2 > hd[dev].nr_sects) {
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end_request(0);
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goto repeat;
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}
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block += hd[dev].start_sect;
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dev /= 5;
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__asm__("divl %4":"=a" (block),"=d" (sec):"0" (block),"1" (0),
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"r" (hd_info[dev].sect));
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__asm__("divl %4":"=a" (cyl),"=d" (head):"0" (block),"1" (0),
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"r" (hd_info[dev].head));
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sec++;
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nsect = CURRENT->nr_sectors;
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if (reset) {
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reset = 0;
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recalibrate = 1;
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reset_hd(CURRENT_DEV);
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return;
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}
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if (recalibrate) {
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recalibrate = 0;
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hd_out(dev,hd_info[CURRENT_DEV].sect,0,0,0,
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WIN_RESTORE,&recal_intr);
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return;
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}
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if (CURRENT->cmd == WRITE) {
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hd_out(dev,nsect,sec,head,cyl,WIN_WRITE,&write_intr);
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for(i=0 ; i<3000 && !(r=inb_p(HD_STATUS)&DRQ_STAT) ; i++)
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/* nothing */ ;
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if (!r) {
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bad_rw_intr();
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goto repeat;
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}
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port_write(HD_DATA,CURRENT->buffer,256);
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} else if (CURRENT->cmd == READ) {
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hd_out(dev,nsect,sec,head,cyl,WIN_READ,&read_intr);
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} else
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panic("unknown hd-command");
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}
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void hd_init(void)
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{
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blk_dev[MAJOR_NR].request_fn = DEVICE_REQUEST;
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set_intr_gate(0x2E,&hd_interrupt);
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outb_p(inb_p(0x21)&0xfb,0x21);
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outb(inb_p(0xA1)&0xbf,0xA1);
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}
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