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annotate src/ata.c @ 86:379332fc1667

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implementing ata read/write
author John Tsiombikas <nuclear@member.fsf.org>
date Wed, 07 Dec 2011 14:03:11 +0200
parents 4ef83db5f4cd
children 178d5a95e6de
rev   line source
nuclear@78 1 #include <stdio.h>
nuclear@78 2 #include <stdlib.h>
nuclear@78 3 #include <string.h>
nuclear@83 4 #include <ctype.h>
nuclear@78 5 #include <inttypes.h>
nuclear@78 6 #include <assert.h>
nuclear@78 7 #include "ata.h"
nuclear@78 8 #include "intr.h"
nuclear@78 9 #include "asmops.h"
nuclear@86 10 #include "mutex.h"
nuclear@78 11
nuclear@78 12 /* registers */
nuclear@78 13 #define REG_DATA 0 /* R/W */
nuclear@78 14 #define REG_ERROR 1 /* R */
nuclear@78 15 #define REG_FEATURES 1 /* W */
nuclear@78 16 #define REG_COUNT 2 /* R/W */
nuclear@78 17 #define REG_LBA0 3 /* R/W */
nuclear@78 18 #define REG_LBA1 4 /* R/W */
nuclear@78 19 #define REG_LBA2 5 /* R/W */
nuclear@78 20 #define REG_DEVICE 6 /* R/W */
nuclear@78 21 #define REG_CMD 7 /* W */
nuclear@78 22 #define REG_STATUS 7 /* R */
nuclear@78 23
nuclear@78 24 #define REG_CTL 518
nuclear@78 25 #define REG_ALTSTAT 518
nuclear@78 26
nuclear@78 27 /* status bit fields */
nuclear@78 28 #define ST_ERR (1 << 0)
nuclear@78 29 #define ST_DRQ (1 << 3)
nuclear@78 30 #define ST_DRDY (1 << 6)
nuclear@78 31 #define ST_BSY (1 << 7)
nuclear@78 32
nuclear@78 33 /* device select bit in control register */
nuclear@78 34 #define DEV_SEL(x) (((x) & 1) << 4)
nuclear@86 35 #define DEV_LBA (1 << 6)
nuclear@78 36
nuclear@78 37 /* ATA commands */
nuclear@78 38 #define CMD_IDENTIFY 0xec
nuclear@86 39 #define CMD_READ 0x20
nuclear@86 40 #define CMD_READ48 0x24
nuclear@86 41 #define CMD_WRITE 0x30
nuclear@86 42 #define CMD_WRITE48 0x34
nuclear@78 43
nuclear@78 44
nuclear@78 45 struct device {
nuclear@78 46 int id; /* id of the device on its ATA interface (0 master, 1 slave) */
nuclear@78 47 int iface; /* ATA interface for this device (0 or 1) */
nuclear@78 48 int port_base; /* interface I/O port base */
nuclear@78 49
nuclear@78 50 uint32_t nsect_lba;
nuclear@78 51 uint64_t nsect_lba48;
nuclear@78 52 };
nuclear@78 53
nuclear@78 54
nuclear@78 55 static int identify(struct device *dev, int iface, int id);
nuclear@78 56 static void select_dev(struct device *dev);
nuclear@78 57 static int wait_busy(struct device *dev);
nuclear@78 58 static int wait_drq(struct device *dev);
nuclear@78 59 static void read_data(struct device *dev, void *buf);
nuclear@78 60 static inline uint8_t read_reg8(struct device *dev, int reg);
nuclear@78 61 static inline uint16_t read_reg16(struct device *dev, int reg);
nuclear@78 62 static inline void write_reg8(struct device *dev, int reg, uint8_t val);
nuclear@78 63 static inline void write_reg16(struct device *dev, int reg, uint16_t val);
nuclear@78 64 static void ata_intr(int inum);
nuclear@80 65 static void *atastr(void *res, void *src, int n);
nuclear@78 66 static char *size_str(uint64_t nsect, char *buf);
nuclear@78 67
nuclear@78 68 /* last drive selected on each bus */
nuclear@78 69 static int drvsel[2] = {-1, -1};
nuclear@78 70
nuclear@78 71 /* 4 possible devices: 2 ATA interfaces with 2 devices each.
nuclear@78 72 * this will never change unless we start querying the PCI config space
nuclear@78 73 * for additional drives (in which case this whole init code must be
nuclear@78 74 * rewritten anyway), but I like it spelt out like this.
nuclear@78 75 */
nuclear@78 76 #define MAX_IFACES 2
nuclear@78 77 #define MAX_DEV (MAX_IFACES * 2)
nuclear@86 78 static struct device devices[MAX_DEV];
nuclear@86 79
nuclear@86 80 static int use_irq;
nuclear@86 81
nuclear@86 82 /* This serves as a sync point for I/O. While the mutex is held,
nuclear@86 83 * some process is doing I/O and all the others must wait.
nuclear@86 84 */
nuclear@86 85 static mutex_t pending;
nuclear@78 86
nuclear@78 87
nuclear@78 88 void init_ata(void)
nuclear@78 89 {
nuclear@78 90 int i;
nuclear@78 91
nuclear@78 92 interrupt(IRQ_TO_INTR(15), ata_intr);
nuclear@78 93
nuclear@78 94 for(i=0; i<MAX_DEV; i++) {
nuclear@78 95 int iface = i / MAX_IFACES;
nuclear@78 96 int id = i % MAX_IFACES;
nuclear@78 97
nuclear@86 98 if(identify(devices + i, iface, id) == -1) {
nuclear@86 99 devices[i].id = -1;
nuclear@78 100 }
nuclear@78 101 }
nuclear@86 102
nuclear@86 103 /* init code done, from now on use the irq sleep/wakeup mechanism */
nuclear@86 104 use_irq = 1;
nuclear@86 105 }
nuclear@86 106
nuclear@86 107 int ata_read_pio(int devno, uint64_t sect, void *buf)
nuclear@86 108 {
nuclear@86 109 int cmd, st, res = -1;
nuclear@86 110 uint32_t sect_low;
nuclear@86 111 struct device *dev = device + devno;
nuclear@86 112
nuclear@86 113 if(dev->id == -1) {
nuclear@86 114 return -1;
nuclear@86 115 }
nuclear@86 116
nuclear@86 117 if(use_irq) {
nuclear@86 118 /* wait for the interface to become available */
nuclear@86 119 mutex_lock(&pending);
nuclear@86 120 }
nuclear@86 121
nuclear@86 122 select_dev(dev);
nuclear@86 123
nuclear@86 124 /* LBA48 requires the high-order bits first */
nuclear@86 125 if(sect >= dev->nsect_lba) {
nuclear@86 126 uint32_t sect_high = (uint32_t)(sect >> 24);
nuclear@86 127 sect_low = (uint32_t)sect & 0xffffff;
nuclear@86 128
nuclear@86 129 if(sect >= dev->nsect_lba48) {
nuclear@86 130 goto end;
nuclear@86 131 }
nuclear@86 132 cmd = CMD_READ48;
nuclear@86 133
nuclear@86 134 write_reg8(dev, REG_COUNT, 0);
nuclear@86 135 write_reg8(dev, REG_LBA0, sect_high & 0xff);
nuclear@86 136 write_reg8(dev, REG_LBA1, (sect_high >> 8) & 0xff);
nuclear@86 137 write_reg8(dev, REG_LBA2, (sect_high >> 16) & 0xff);
nuclear@86 138 } else {
nuclear@86 139 cmd = CMD_READ;
nuclear@86 140 sect_low = (uint32_t)sect & 0xffffff;
nuclear@86 141 }
nuclear@86 142
nuclear@86 143 write_reg8(dev, REG_COUNT, 1);
nuclear@86 144 write_reg8(dev, REG_LBA0, sect_low & 0xff);
nuclear@86 145 write_reg8(dev, REG_LBA1, (sect_low >> 8) & 0xff);
nuclear@86 146 write_reg8(dev, REG_LBA2, (sect_low >> 16) & 0xff);
nuclear@86 147 write_reg8(dev, REG_DEVICE, ((sect_low >> 24) & 0xf) | DEV_LBA | DEV_SEL(dev->id))
nuclear@86 148 /* execute */
nuclear@86 149 write_reg8(dev, REG_CMD, cmd);
nuclear@86 150
nuclear@86 151 /* wait for the data to become available */
nuclear@86 152 do {
nuclear@86 153 if(use_irq) {
nuclear@86 154 /* also sleep on the mutex if we're called from userspace */
nuclear@86 155 wait(&pending);
nuclear@86 156 }
nuclear@86 157 } while((st = read_reg8(dev, REG_ALTSTAT)) & (ST_DRQ | ST_ERR) == 0);
nuclear@86 158
nuclear@86 159 if(st & ST_ERR) {
nuclear@86 160 print_error();
nuclear@86 161 goto end;
nuclear@86 162 }
nuclear@86 163
nuclear@86 164 /* read the data and we're done */
nuclear@86 165 read_data(dev, buf);
nuclear@86 166 res = 0;
nuclear@86 167 end:
nuclear@86 168 if(use_irq) {
nuclear@86 169 mutex_unlock(&pending);
nuclear@86 170 }
nuclear@86 171 return res;
nuclear@86 172 }
nuclear@86 173
nuclear@86 174 int ata_write_pio(int devno, uint64_t sect, void *buf)
nuclear@86 175 {
nuclear@86 176 if(dev[devno].id == -1) {
nuclear@86 177 return -1;
nuclear@86 178 }
nuclear@78 179 }
nuclear@78 180
nuclear@78 181 static int identify(struct device *dev, int iface, int id)
nuclear@78 182 {
nuclear@78 183 /* base address of the two ATA interfaces */
nuclear@78 184 static const int port_base[] = {0x1f0, 0x170};
nuclear@78 185 unsigned char st;
nuclear@78 186 uint16_t *info;
nuclear@78 187 char textbuf[42]; /* at most we need 40 chars for ident strings */
nuclear@78 188
nuclear@78 189 dev->id = id;
nuclear@78 190 dev->iface = iface;
nuclear@78 191 dev->port_base = port_base[iface];
nuclear@78 192
nuclear@78 193 /* a status of 0xff means there's no drive on the interface */
nuclear@78 194 if((st = read_reg8(dev, REG_ALTSTAT)) == 0xff) {
nuclear@78 195 return -1;
nuclear@78 196 }
nuclear@78 197
nuclear@78 198 select_dev(dev);
nuclear@78 199
nuclear@78 200 write_reg8(dev, REG_CMD, CMD_IDENTIFY);
nuclear@78 201
nuclear@78 202 if(!(st = read_reg8(dev, REG_ALTSTAT)) || (st & ST_ERR)) {
nuclear@78 203 /* does not exist */
nuclear@78 204 return -1;
nuclear@78 205 }
nuclear@78 206 if(wait_busy(dev) == -1) {
nuclear@78 207 /* got ST_ERR, not ATA */
nuclear@78 208 return -1;
nuclear@78 209 }
nuclear@78 210
nuclear@78 211 info = malloc(512);
nuclear@78 212 assert(info);
nuclear@78 213
nuclear@78 214 /* read the device information */
nuclear@78 215 read_data(dev, info);
nuclear@78 216
nuclear@78 217 /* print model and serial */
nuclear@83 218 printf("ata%d: %s", (dev->iface << 1) | dev->id, atastr(textbuf, info + 27, 40));
nuclear@83 219 printf(" [s/n: %s]", atastr(textbuf, info + 10, 20));
nuclear@78 220
nuclear@78 221 dev->nsect_lba = *(uint32_t*)(info + 60);
nuclear@78 222 dev->nsect_lba48 = *(uint64_t*)(info + 100) & 0xffffffffffffull;
nuclear@78 223
nuclear@78 224 if(!dev->nsect_lba) {
nuclear@78 225 printf(" drive does not support LBA, ignoring!\n");
nuclear@78 226 free(info);
nuclear@78 227 return -1;
nuclear@78 228 }
nuclear@78 229
nuclear@78 230 if(dev->nsect_lba48) {
nuclear@78 231 size_str(dev->nsect_lba48, textbuf);
nuclear@78 232 } else {
nuclear@78 233 size_str(dev->nsect_lba, textbuf);
nuclear@78 234 }
nuclear@83 235 printf(" size: %s\n", textbuf);
nuclear@78 236
nuclear@78 237 free(info);
nuclear@78 238 return 0;
nuclear@78 239 }
nuclear@78 240
nuclear@78 241 static void select_dev(struct device *dev)
nuclear@78 242 {
nuclear@78 243 /* if this is the currently selected device, thy work is done */
nuclear@78 244 if(drvsel[dev->iface] == dev->id)
nuclear@78 245 return;
nuclear@78 246
nuclear@78 247 /* wait for BSY and DRQ to clear */
nuclear@78 248 while(read_reg8(dev, REG_ALTSTAT) & (ST_BSY | ST_DRQ));
nuclear@78 249
nuclear@78 250 /* set the correct device bit to the device register */
nuclear@78 251 write_reg8(dev, REG_DEVICE, DEV_SEL(dev->id));
nuclear@86 252
nuclear@86 253 /* wait a bit to allow the device time to respond */
nuclear@86 254 iodelay(); iodelay(); iodelay(); iodelay();
nuclear@78 255 }
nuclear@78 256
nuclear@78 257 static int wait_busy(struct device *dev)
nuclear@78 258 {
nuclear@78 259 unsigned char st;
nuclear@78 260
nuclear@78 261 do {
nuclear@78 262 st = read_reg8(dev, REG_ALTSTAT);
nuclear@78 263 } while((st & ST_BSY) && !(st & ST_ERR));
nuclear@78 264
nuclear@78 265 return st & ST_ERR ? -1 : 0;
nuclear@78 266 }
nuclear@78 267
nuclear@78 268 static int wait_drq(struct device *dev)
nuclear@78 269 {
nuclear@78 270 unsigned char st;
nuclear@78 271
nuclear@78 272 do {
nuclear@78 273 st = read_reg8(dev, REG_ALTSTAT);
nuclear@78 274 } while(!(st & (ST_DRQ | ST_ERR)));
nuclear@78 275
nuclear@78 276 return st & ST_ERR ? -1 : 0;
nuclear@78 277 }
nuclear@78 278
nuclear@78 279 static void read_data(struct device *dev, void *buf)
nuclear@78 280 {
nuclear@78 281 int i;
nuclear@78 282 uint16_t *ptr = buf;
nuclear@78 283
nuclear@78 284 /* wait for the data request from the drive */
nuclear@78 285 wait_drq(dev);
nuclear@78 286
nuclear@78 287 /* ready to transfer */
nuclear@78 288 for(i=0; i<256; i++) {
nuclear@78 289 *ptr++ = read_reg16(dev, REG_DATA);
nuclear@78 290 }
nuclear@78 291 }
nuclear@78 292
nuclear@78 293 static inline uint8_t read_reg8(struct device *dev, int reg)
nuclear@78 294 {
nuclear@78 295 uint8_t val;
nuclear@78 296 inb(val, dev->port_base + reg);
nuclear@78 297 return val;
nuclear@78 298 }
nuclear@78 299
nuclear@78 300 static inline uint16_t read_reg16(struct device *dev, int reg)
nuclear@78 301 {
nuclear@78 302 uint16_t val;
nuclear@78 303 inw(val, dev->port_base + reg);
nuclear@78 304 return val;
nuclear@78 305 }
nuclear@78 306
nuclear@78 307 static inline void write_reg8(struct device *dev, int reg, uint8_t val)
nuclear@78 308 {
nuclear@78 309 outb(val, dev->port_base + reg);
nuclear@78 310 }
nuclear@78 311
nuclear@78 312 static inline void write_reg16(struct device *dev, int reg, uint16_t val)
nuclear@78 313 {
nuclear@78 314 outw(val, dev->port_base + reg);
nuclear@78 315 }
nuclear@78 316
nuclear@78 317 static void ata_intr(int inum)
nuclear@78 318 {
nuclear@78 319 printf("ATA interrupt\n");
nuclear@78 320 }
nuclear@78 321
nuclear@80 322 static void *atastr(void *res, void *src, int n)
nuclear@80 323 {
nuclear@80 324 int i;
nuclear@80 325 uint16_t *sptr = (uint16_t*)src;
nuclear@80 326 char *dptr = res;
nuclear@80 327
nuclear@80 328 for(i=0; i<n/2; i++) {
nuclear@80 329 *dptr++ = (*sptr & 0xff00) >> 8;
nuclear@80 330 *dptr++ = *sptr++ & 0xff;
nuclear@80 331 }
nuclear@83 332
nuclear@83 333 while(isspace(*--dptr));
nuclear@83 334 *++dptr = 0;
nuclear@80 335 return res;
nuclear@80 336 }
nuclear@80 337
nuclear@78 338 static char *size_str(uint64_t nsect, char *buf)
nuclear@78 339 {
nuclear@78 340 static const char *suffix[] = {"kb", "mb", "gb", "tb", "pb", 0};
nuclear@78 341 int i;
nuclear@82 342 unsigned int rem;
nuclear@78 343
nuclear@78 344 /* start with kilobytes */
nuclear@78 345 nsect /= 2;
nuclear@78 346
nuclear@78 347 for(i=0; nsect >= 1024 && suffix[i + 1]; i++) {
nuclear@82 348 rem = nsect % 1024;
nuclear@78 349 nsect /= 1024;
nuclear@78 350 }
nuclear@82 351 sprintf(buf, "%u.%u%s", (unsigned int)nsect, 100 * rem / 1024, suffix[i]);
nuclear@78 352 return buf;
nuclear@78 353 }
nuclear@78 354