/* * acsi.c -- Device driver for Atari ACSI hard disks * * Copyright 1994 Roman Hodek * * Some parts are based on hd.c by Linus Torvalds * * This file is subject to the terms and conditions of the GNU General Public * License. See the file COPYING in the main directory of this archive for * more details. * */ /* * Still to in this file: * - If a command ends with an error status (!= 0), the following * REQUEST SENSE commands (4 to fill the ST-DMA FIFO) are done by * polling the _IRQ signal (not interrupt-driven). This should be * avoided in future because it takes up a non-neglectible time in * the interrupt service routine while interrupts are disabled. * Maybe a timer interrupt will get lost :-( */ /* * General notes: * * - All ACSI devices (disks, CD-ROMs, ...) use major number 28. * Minors are organized like it is with SCSI: The upper 4 bits * identify the device, the lower 4 bits the partition. * The device numbers (the upper 4 bits) are given in the same * order as the devices are found on the bus. * - Up to 8 LUNs are supported for each target (if CONFIG_ACSI_MULTI_LUN * is defined), but only a total of 16 devices (due to minor * numbers...). Note that Atari allows only a maximum of 4 targets * (i.e. controllers, not devices) on the ACSI bus! * - A optimizing scheme similar to SCSI scatter-gather is implemented. * - Removable media are supported. After a medium change to device * is reinitialized (partition check etc.). Also, if the device * knows the PREVENT/ALLOW MEDIUM REMOVAL command, the door should * be locked and unlocked when mounting the first or unmounting the * last filesystem on the device. The code is untested, because I * don't have a removable hard disk. * */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* for SCSI_IOCTL_GET_IDLUN */ #include #include /* for HDIO_GETGEO */ #include #include #include #include #include #include #include #include #include #include #include #include static void (*do_acsi)(void) = NULL; static struct request_queue *acsi_queue; #define QUEUE (acsi_queue) #define CURRENT elv_next_request(acsi_queue) #define DEBUG #undef DEBUG_DETECT #undef NO_WRITE #define MAX_ERRORS 8 /* Max read/write errors/sector */ #define MAX_LUN 8 /* Max LUNs per target */ #define MAX_DEV 16 #define ACSI_BUFFER_SIZE (16*1024) /* "normal" ACSI buffer size */ #define ACSI_BUFFER_MINSIZE (2048) /* min. buf size if ext. DMA */ #define ACSI_BUFFER_SIZE_ORDER 2 /* order size for above */ #define ACSI_BUFFER_MINSIZE_ORDER 0 /* order size for above */ #define ACSI_BUFFER_SECTORS (ACSI_BUFFER_SIZE/512) #define ACSI_BUFFER_ORDER \ (ATARIHW_PRESENT(EXTD_DMA) ? \ ACSI_BUFFER_MINSIZE_ORDER : \ ACSI_BUFFER_SIZE_ORDER) #define ACSI_TIMEOUT (4*HZ) /* minimum delay between two commands */ #define COMMAND_DELAY 500 typedef enum { NONE, HARDDISK, CDROM } ACSI_TYPE; struct acsi_info_struct { ACSI_TYPE type; /* type of device */ unsigned target; /* target number */ unsigned lun; /* LUN in target controller */ unsigned removable : 1; /* Flag for removable media */ unsigned read_only : 1; /* Flag for read only devices */ unsigned old_atari_disk : 1; /* Is an old Atari disk */ unsigned changed : 1; /* Medium has been changed */ unsigned long size; /* #blocks */ int access_count; } acsi_info[MAX_DEV]; /* * SENSE KEYS */ #define NO_SENSE 0x00 #define RECOVERED_ERROR 0x01 #define NOT_READY 0x02 #define MEDIUM_ERROR 0x03 #define HARDWARE_ERROR 0x04 #define ILLEGAL_REQUEST 0x05 #define UNIT_ATTENTION 0x06 #define DATA_PROTECT 0x07 #define BLANK_CHECK 0x08 #define COPY_ABORTED 0x0a #define ABORTED_COMMAND 0x0b #define VOLUME_OVERFLOW 0x0d #define MISCOMPARE 0x0e /* * DEVICE TYPES */ #define TYPE_DISK 0x00 #define TYPE_TAPE 0x01 #define TYPE_WORM 0x04 #define TYPE_ROM 0x05 #define TYPE_MOD 0x07 #define TYPE_NO_LUN 0x7f /* The data returned by MODE SENSE differ between the old Atari * hard disks and SCSI disks connected to ACSI. In the following, both * formats are defined and some macros to operate on them potably. */ typedef struct { unsigned long dummy[2]; unsigned long sector_size; unsigned char format_code; #define ATARI_SENSE_FORMAT_FIX 1 #define ATARI_SENSE_FORMAT_CHNG 2 unsigned char cylinders_h; unsigned char cylinders_l; unsigned char heads; unsigned char reduced_h; unsigned char reduced_l; unsigned char precomp_h; unsigned char precomp_l; unsigned char landing_zone; unsigned char steprate; unsigned char type; #define ATARI_SENSE_TYPE_FIXCHNG_MASK 4 #define ATARI_SENSE_TYPE_SOFTHARD_MASK 8 #define ATARI_SENSE_TYPE_FIX 4 #define ATARI_SENSE_TYPE_CHNG 0 #define ATARI_SENSE_TYPE_SOFT 0 #define ATARI_SENSE_TYPE_HARD 8 unsigned char sectors; } ATARI_SENSE_DATA; #define ATARI_CAPACITY(sd) \ (((int)((sd).cylinders_h<<8)|(sd).cylinders_l) * \ (sd).heads * (sd).sectors) typedef struct { unsigned char dummy1; unsigned char medium_type; unsigned char dummy2; unsigned char descriptor_size; unsigned long block_count; unsigned long sector_size; /* Page 0 data */ unsigned char page_code; unsigned char page_size; unsigned char page_flags; unsigned char qualifier; } SCSI_SENSE_DATA; #define SCSI_CAPACITY(sd) ((sd).block_count & 0xffffff) typedef union { ATARI_SENSE_DATA atari; SCSI_SENSE_DATA scsi; } SENSE_DATA; #define SENSE_TYPE_UNKNOWN 0 #define SENSE_TYPE_ATARI 1 #define SENSE_TYPE_SCSI 2 #define SENSE_TYPE(sd) \ (((sd).atari.dummy[0] == 8 && \ ((sd).atari.format_code == 1 || \ (sd).atari.format_code == 2)) ? SENSE_TYPE_ATARI : \ ((sd).scsi.dummy1 >= 11) ? SENSE_TYPE_SCSI : \ SENSE_TYPE_UNKNOWN) #define CAPACITY(sd) \ (SENSE_TYPE(sd) == SENSE_TYPE_ATARI ? \ ATARI_CAPACITY((sd).atari) : \ SCSI_CAPACITY((sd).scsi)) #define SECTOR_SIZE(sd) \ (SENSE_TYPE(sd) == SENSE_TYPE_ATARI ? \ (sd).atari.sector_size : \ (sd).scsi.sector_size & 0xffffff) /* Default size if capacity cannot be determined (1 GByte) */ #define DEFAULT_SIZE 0x1fffff #define CARTRCH_STAT(aip,buf) \ (aip->old_atari_disk ? \ (((buf)[0] & 0x7f) == 0x28) : \ ((((buf)[0] & 0x70) == 0x70) ? \ (((buf)[2] & 0x0f) == 0x06) : \ (((buf)[0] & 0x0f) == 0x06))) \ /* These two are also exported to other drivers that work on the ACSI bus and * need an ST-RAM buffer. */ char *acsi_buffer; unsigned long phys_acsi_buffer; static int NDevices; static int CurrentNReq; static int CurrentNSect; static char *CurrentBuffer; static DEFINE_SPINLOCK(acsi_lock); #define SET_TIMER() mod_timer(&acsi_timer, jiffies + ACSI_TIMEOUT) #define CLEAR_TIMER() del_timer(&acsi_timer) static unsigned long STramMask; #define STRAM_ADDR(a) (((a) & STramMask) == 0) /* ACSI commands */ static char tur_cmd[6] = { 0x00, 0, 0, 0, 0, 0 }; static char modesense_cmd[6] = { 0x1a, 0, 0, 0, 24, 0 }; static char modeselect_cmd[6] = { 0x15, 0, 0, 0, 12, 0 }; static char inquiry_cmd[6] = { 0x12, 0, 0, 0,255, 0 }; static char reqsense_cmd[6] = { 0x03, 0, 0, 0, 4, 0 }; static char read_cmd[6] = { 0x08, 0, 0, 0, 0, 0 }; static char write_cmd[6] = { 0x0a, 0, 0, 0, 0, 0 }; static char pa_med_rem_cmd[6] = { 0x1e, 0, 0, 0, 0, 0 }; #define CMDSET_TARG_LUN(cmd,targ,lun) \ do { \ cmd[0] = (cmd[0] & ~0xe0) | (targ)<<5; \ cmd[1] = (cmd[1] & ~0xe0) | (lun)<<5; \ } while(0) #define CMDSET_BLOCK(cmd,blk) \ do { \ unsigned long __blk = (blk); \ cmd[3] = __blk; __blk >>= 8; \ cmd[2] = __blk; __blk >>= 8; \ cmd[1] = (cmd[1] & 0xe0) | (__blk & 0x1f); \ } while(0) #define CMDSET_LEN(cmd,len) \ do { \ cmd[4] = (len); \ } while(0) /* ACSI errors (from REQUEST SENSE); There are two tables, one for the * old Atari disks and one for SCSI on ACSI disks. */ struct acsi_error { unsigned char code; const char *text; } atari_acsi_errors[] = { { 0x00, "No error (??)" }, { 0x01, "No index pulses" }, { 0x02, "Seek not complete" }, { 0x03, "Write fault" }, { 0x04, "Drive not ready" }, { 0x06, "No Track 00 signal" }, { 0x10, "ECC error in ID field" }, { 0x11, "Uncorrectable data error" }, { 0x12, "ID field address mark not found" }, { 0x13, "Data field address mark not found" }, { 0x14, "Record not found" }, { 0x15, "Seek error" }, { 0x18, "Data check in no retry mode" }, { 0x19, "ECC error during verify" }, { 0x1a, "Access to bad block" }, { 0x1c, "Unformatted or bad format" }, { 0x20, "Invalid command" }, { 0x21, "Invalid block address" }, { 0x23, "Volume overflow" }, { 0x24, "Invalid argument" }, { 0x25, "Invalid drive number" }, { 0x26, "Byte zero parity check" }, { 0x28, "Cartride changed" }, { 0x2c, "Error count overflow" }, { 0x30, "Controller selftest failed" } }, scsi_acsi_errors[] = { { 0x00, "No error (??)" }, { 0x01, "Recovered error" }, { 0x02, "Drive not ready" }, { 0x03, "Uncorrectable medium error" }, { 0x04, "Hardware error" }, { 0x05, "Illegal request" }, { 0x06, "Unit attention (Reset or cartridge changed)" }, { 0x07, "Data protection" }, { 0x08, "Blank check" }, { 0x0b, "Aborted Command" }, { 0x0d, "Volume overflow" } }; /***************************** Prototypes *****************************/ static int acsicmd_dma( const char *cmd, char *buffer, int blocks, int rwflag, int enable); static int acsi_reqsense( char *buffer, int targ, int lun); static void acsi_print_error(const unsigned char *errblk, struct acsi_info_struct *aip); static irqreturn_t acsi_interrupt (int irq, void *data); static void unexpected_acsi_interrupt( void ); static void bad_rw_intr( void ); static void read_intr( void ); static void write_intr( void); static void acsi_times_out( unsigned long dummy ); static void copy_to_acsibuffer( void ); static void copy_from_acsibuffer( void ); static void do_end_requests( void ); static void do_acsi_request( request_queue_t * ); static void redo_acsi_request( void ); static int acsi_ioctl( struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg ); static int acsi_open( struct inode * inode, struct file * filp ); static int acsi_release( struct inode * inode, struct file * file ); static void acsi_prevent_removal(struct acsi_info_struct *aip, int flag ); static int acsi_change_blk_size( int target, int lun); static int acsi_mode_sense( int target, int lun, SENSE_DATA *sd ); static int acsi_revalidate (struct gendisk *disk); /************************* End of Prototypes **************************/ DEFINE_TIMER(acsi_timer, acsi_times_out, 0, 0); #ifdef CONFIG_ATARI_SLM extern int attach_slm( int target, int lun ); extern int slm_init( void ); #endif /*********************************************************************** * * ACSI primitives * **********************************************************************/ /* * The following two functions wait for _IRQ to become Low or High, * resp., with a timeout. The 'timeout' parameter is in jiffies * (10ms). * If the functions are called with timer interrupts on (int level < * 6), the timeout is based on the 'jiffies' variable to provide exact * timeouts for device probing etc. * If interrupts are disabled, the number of tries is based on the * 'loops_per_jiffy' variable. A rough estimation is sufficient here... */ #define INT_LEVEL \ ({ unsigned __sr; \ __asm__ __volatile__ ( "movew %/sr,%0" : "=dm" (__sr) ); \ (__sr >> 8) & 7; \ }) int acsi_wait_for_IRQ( unsigned timeout ) { if (INT_LEVEL < 6) { unsigned long maxjif = jiffies + timeout; while (time_before(jiffies, maxjif)) if (!(mfp.par_dt_reg & 0x20)) return( 1 ); } else { long tries = loops_per_jiffy / 8 * timeout; while( --tries >= 0 ) if (!(mfp.par_dt_reg & 0x20)) return( 1 ); } return( 0 ); /* timeout! */ } int acsi_wait_for_noIRQ( unsigned timeout ) { if (INT_LEVEL < 6) { unsigned long maxjif = jiffies + timeout; while (time_before(jiffies, maxjif)) if (mfp.par_dt_reg & 0x20) return( 1 ); } else { long tries = loops_per_jiffy * timeout / 8; while( tries-- >= 0 ) if (mfp.par_dt_reg & 0x20) return( 1 ); } return( 0 ); /* timeout! */ } static struct timeval start_time; void acsi_delay_start(void) { do_gettimeofday(&start_time); } /* wait from acsi_delay_start to now usec (<1E6) usec */ void acsi_delay_end(long usec) { struct timeval end_time; long deltau,deltas; do_gettimeofday(&end_time); deltau=end_time.tv_usec - start_time.tv_usec; deltas=end_time.tv_sec - start_time.tv_sec; if (deltas > 1 || deltas < 0) return; if (deltas > 0) deltau += 1000*1000; if (deltau >= usec) return; udelay(usec-deltau); } /* acsicmd_dma() sends an ACSI command and sets up the DMA to transfer * 'blocks' blocks of 512 bytes from/to 'buffer'. * Because the _IRQ signal is used for handshaking the command bytes, * the ACSI interrupt has to be disabled in this function. If the end * of the operation should be signalled by a real interrupt, it has to be * reenabled afterwards. */ static int acsicmd_dma( const char *cmd, char *buffer, int blocks, int rwflag, int enable) { unsigned long flags, paddr; int i; #ifdef NO_WRITE if (rwflag || *cmd == 0x0a) { printk( "ACSI: Write commands disabled!\n" ); return( 0 ); } #endif rwflag = rwflag ? 0x100 : 0; paddr = virt_to_phys( buffer ); acsi_delay_end(COMMAND_DELAY); DISABLE_IRQ(); local_irq_save(flags); /* Low on A1 */ dma_wd.dma_mode_status = 0x88 | rwflag; MFPDELAY(); /* set DMA address */ dma_wd.dma_lo = (unsigned char)paddr; paddr >>= 8; MFPDELAY(); dma_wd.dma_md = (unsigned char)paddr; paddr >>= 8; MFPDELAY(); if (ATARIHW_PRESENT(EXTD_DMA)) st_dma_ext_dmahi = (unsigned short)paddr; else dma_wd.dma_hi = (unsigned char)paddr; MFPDELAY(); local_irq_restore(flags); /* send the command bytes except the last */ for( i = 0; i < 5; ++i ) { DMA_LONG_WRITE( *cmd++, 0x8a | rwflag ); udelay(20); if (!acsi_wait_for_IRQ( HZ/2 )) return( 0 ); /* timeout */ } /* Clear FIFO and switch DMA to correct direction */ dma_wd.dma_mode_status = 0x92 | (rwflag ^ 0x100); MFPDELAY(); dma_wd.dma_mode_status = 0x92 | rwflag; MFPDELAY(); /* How many sectors for DMA */ dma_wd.fdc_acces_seccount = blocks; MFPDELAY(); /* send last command byte */ dma_wd.dma_mode_status = 0x8a | rwflag; MFPDELAY(); DMA_LONG_WRITE( *cmd++, 0x0a | rwflag ); if (enable) ENABLE_IRQ(); udelay(80); return( 1 ); } /* * acsicmd_nodma() sends an ACSI command that requires no DMA. */ int acsicmd_nodma( const char *cmd, int enable) { int i; acsi_delay_end(COMMAND_DELAY); DISABLE_IRQ(); /* send first command byte */ dma_wd.dma_mode_status = 0x88; MFPDELAY(); DMA_LONG_WRITE( *cmd++, 0x8a ); udelay(20); if (!acsi_wait_for_IRQ( HZ/2 )) return( 0 ); /* timeout */ /* send the intermediate command bytes */ for( i = 0; i < 4; ++i ) { DMA_LONG_WRITE( *cmd++, 0x8a ); udelay(20); if (!acsi_wait_for_IRQ( HZ/2 )) return( 0 ); /* timeout */ } /* send last command byte */ DMA_LONG_WRITE( *cmd++, 0x0a ); if (enable) ENABLE_IRQ(); udelay(80); return( 1 ); /* Note that the ACSI interrupt is still disabled after this * function. If you want to get the IRQ delivered, enable it manually! */ } static int acsi_reqsense( char *buffer, int targ, int lun) { CMDSET_TARG_LUN( reqsense_cmd, targ, lun); if (!acsicmd_dma( reqsense_cmd, buffer, 1, 0, 0 )) return( 0 ); if (!acsi_wait_for_IRQ( 10 )) return( 0 ); acsi_getstatus(); if (!acsicmd_nodma( reqsense_cmd, 0 )) return( 0 ); if (!acsi_wait_for_IRQ( 10 )) return( 0 ); acsi_getstatus(); if (!acsicmd_nodma( reqsense_cmd, 0 )) return( 0 ); if (!acsi_wait_for_IRQ( 10 )) return( 0 ); acsi_getstatus(); if (!acsicmd_nodma( reqsense_cmd, 0 )) return( 0 ); if (!acsi_wait_for_IRQ( 10 )) return( 0 ); acsi_getstatus(); dma_cache_maintenance( virt_to_phys(buffer), 16, 0 ); return( 1 ); } /* * ACSI status phase: get the status byte from the bus * * I've seen several times that a 0xff status is read, propably due to * a timing error. In this case, the procedure is repeated after the * next _IRQ edge. */ int acsi_getstatus( void ) { int status; DISABLE_IRQ(); for(;;) { if (!acsi_wait_for_IRQ( 100 )) { acsi_delay_start(); return( -1 ); } dma_wd.dma_mode_status = 0x8a; MFPDELAY(); status = dma_wd.fdc_acces_seccount; if (status != 0xff) break; #ifdef DEBUG printk("ACSI: skipping 0xff status byte\n" ); #endif udelay(40); acsi_wait_for_noIRQ( 20 ); } dma_wd.dma_mode_status = 0x80; udelay(40); acsi_wait_for_noIRQ( 20 ); acsi_delay_start(); return( status & 0x1f ); /* mask of the device# */ } #if (defined(CONFIG_ATARI_SLM) || defined(CONFIG_ATARI_SLM_MODULE)) /* Receive data in an extended status phase. Needed by SLM printer. */ int acsi_extstatus( char *buffer, int cnt ) { int status; DISABLE_IRQ(); udelay(80); while( cnt-- > 0 ) { if (!acsi_wait_for_IRQ( 40 )) return( 0 ); dma_wd.dma_mode_status = 0x8a; MFPDELAY(); status = dma_wd.fdc_acces_seccount; MFPDELAY(); *buffer++ = status & 0xff; udelay(40); } return( 1 ); } /* Finish an extended status phase */ void acsi_end_extstatus( void ) { dma_wd.dma_mode_status = 0x80; udelay(40); acsi_wait_for_noIRQ( 20 ); acsi_delay_start(); } /* Send data in an extended command phase */ int acsi_extcmd( unsigned char *buffer, int cnt ) { while( cnt-- > 0 ) { DMA_LONG_WRITE( *buffer++, 0x8a ); udelay(20); if (!acsi_wait_for_IRQ( HZ/2 )) return( 0 ); /* timeout */ } return( 1 ); } #endif static void acsi_print_error(const unsigned char *errblk, struct acsi_info_struct *aip) { int atari_err, i, errcode; struct acsi_error *arr; atari_err = aip->old_atari_disk; if (atari_err) errcode = errblk[0] & 0x7f; else if ((errblk[0] & 0x70) == 0x70) errcode = errblk[2] & 0x0f; else errcode = errblk[0] & 0x0f; printk( KERN_ERR "ACSI error 0x%02x", errcode ); if (errblk[0] & 0x80) printk( " for sector %d", ((errblk[1] & 0x1f) << 16) | (errblk[2] << 8) | errblk[0] ); arr = atari_err ? atari_acsi_errors : scsi_acsi_errors; i = atari_err ? sizeof(atari_acsi_errors)/sizeof(*atari_acsi_errors) : sizeof(scsi_acsi_errors)/sizeof(*scsi_acsi_errors); for( --i; i >= 0; --i ) if (arr[i].code == errcode) break; if (i >= 0) printk( ": %s\n", arr[i].text ); } /******************************************************************* * * ACSI interrupt routine * Test, if this is a ACSI interrupt and call the irq handler * Otherwise ignore this interrupt. * *******************************************************************/ static irqreturn_t acsi_interrupt(int irq, void *data ) { void (*acsi_irq_handler)(void) = do_acsi; do_acsi = NULL; CLEAR_TIMER(); if (!acsi_irq_handler) acsi_irq_handler = unexpected_acsi_interrupt; acsi_irq_handler(); return IRQ_HANDLED; } /****************************************************************** * * The Interrupt handlers * *******************************************************************/ static void unexpected_acsi_interrupt( void ) { printk( KERN_WARNING "Unexpected ACSI interrupt\n" ); } /* This function is called in case of errors. Because we cannot reset * the ACSI bus or a single device, there is no other choice than * retrying several times :-( */ static void bad_rw_intr( void ) { if (!CURRENT) return; if (++CURRENT->errors >= MAX_ERRORS) end_request(CURRENT, 0); /* Otherwise just retry */ } static void read_intr( void ) { int status; status = acsi_getstatus(); if (status != 0) { struct gendisk *disk = CURRENT->rq_disk; struct acsi_info_struct *aip = disk->private_data; printk(KERN_ERR "%s: ", disk->disk_name); if (!acsi_reqsense(acsi_buffer, aip->target, aip->lun)) printk( "ACSI error and REQUEST SENSE failed (status=0x%02x)\n", status ); else { acsi_print_error(acsi_buffer, aip); if (CARTRCH_STAT(aip, acsi_buffer)) aip->changed = 1; } ENABLE_IRQ(); bad_rw_intr(); redo_acsi_request(); return; } dma_cache_maintenance( virt_to_phys(CurrentBuffer), CurrentNSect*512, 0 ); if (CurrentBuffer == acsi_buffer) copy_from_acsibuffer(); do_end_requests(); redo_acsi_request(); } static void write_intr(void) { int status; status = acsi_getstatus(); if (status != 0) { struct gendisk *disk = CURRENT->rq_disk; struct acsi_info_struct *aip = disk->private_data; printk( KERN_ERR "%s: ", disk->disk_name); if (!acsi_reqsense( acsi_buffer, aip->target, aip->lun)) printk( "ACSI error and REQUEST SENSE failed (status=0x%02x)\n", status ); else { acsi_print_error(acsi_buffer, aip); if (CARTRCH_STAT(aip, acsi_buffer)) aip->changed = 1; } bad_rw_intr(); redo_acsi_request(); return; } do_end_requests(); redo_acsi_request(); } static void acsi_times_out( unsigned long dummy ) { DISABLE_IRQ(); if (!do_acsi) return; do_acsi = NULL; printk( KERN_ERR "ACSI timeout\n" ); if (!CURRENT) return; if (++CURRENT->errors >= MAX_ERRORS) { #ifdef DEBUG printk( KERN_ERR "ACSI: too many errors.\n" ); #endif end_request(CURRENT, 0); } redo_acsi_request(); } /*********************************************************************** * * Scatter-gather utility functions * ***********************************************************************/ static void copy_to_acsibuffer( void ) { int i; char *src, *dst; struct buffer_head *bh; src = CURRENT->buffer; dst = acsi_buffer; bh = CURRENT->bh; if (!bh) memcpy( dst, src, CurrentNSect*512 ); else for( i = 0; i < CurrentNReq; ++i ) { memcpy( dst, src, bh->b_size ); dst += bh->b_size; if ((bh = bh->b_reqnext)) src = bh->b_data; } } static void copy_from_acsibuffer( void ) { int i; char *src, *dst; struct buffer_head *bh; dst = CURRENT->buffer; src = acsi_buffer; bh = CURRENT->bh; if (!bh) memcpy( dst, src, CurrentNSect*512 ); else for( i = 0; i < CurrentNReq; ++i ) { memcpy( dst, src, bh->b_size ); src += bh->b_size; if ((bh = bh->b_reqnext)) dst = bh->b_data; } } static void do_end_requests( void ) { int i, n; if (!CURRENT->bh) { CURRENT->nr_sectors -= CurrentNSect; CURRENT->current_nr_sectors -= CurrentNSect; CURRENT->sector += CurrentNSect; if (CURRENT->nr_sectors == 0) end_request(CURRENT, 1); } else { for( i = 0; i < CurrentNReq; ++i ) { n = CURRENT->bh->b_size >> 9; CURRENT->nr_sectors -= n; CURRENT->current_nr_sectors -= n; CURRENT->sector += n; end_request(CURRENT, 1); } } } /*********************************************************************** * * do_acsi_request and friends * ***********************************************************************/ static void do_acsi_request( request_queue_t * q ) { stdma_lock( acsi_interrupt, NULL ); redo_acsi_request(); } static void redo_acsi_request( void ) { unsigned block, target, lun, nsect; char *buffer; unsigned long pbuffer; struct buffer_head *bh; struct gendisk *disk; struct acsi_info_struct *aip; repeat: CLEAR_TIMER(); if (do_acsi) return; if (!CURRENT) { do_acsi = NULL; ENABLE_IRQ(); stdma_release(); return; } disk = CURRENT->rq_disk; aip = disk->private_data; if (CURRENT->bh) { if (!CURRENT->bh && !buffer_locked(CURRENT->bh)) panic("ACSI: block not locked"); } block = CURRENT->sector; if (block+CURRENT->nr_sectors >= get_capacity(disk)) { #ifdef DEBUG printk( "%s: attempted access for blocks %d...%ld past end of device at block %ld.\n", disk->disk_name, block, block + CURRENT->nr_sectors - 1, get_capacity(disk)); #endif end_request(CURRENT, 0); goto repeat; } if (aip->changed) { printk( KERN_NOTICE "%s: request denied because cartridge has " "been changed.\n", disk->disk_name); end_request(CURRENT, 0); goto repeat; } target = aip->target; lun = aip->lun; /* Find out how many sectors should be transferred from/to * consecutive buffers and thus can be done with a single command. */ buffer = CURRENT->buffer; pbuffer = virt_to_phys(buffer); nsect = CURRENT->current_nr_sectors; CurrentNReq = 1; if ((bh = CURRENT->bh) && bh != CURRENT->bhtail) { if (!STRAM_ADDR(pbuffer)) { /* If transfer is done via the ACSI buffer anyway, we can * assemble as much bh's as fit in the buffer. */ while( (bh = bh->b_reqnext) ) { if (nsect + (bh->b_size>>9) > ACSI_BUFFER_SECTORS) break; nsect += bh->b_size >> 9; ++CurrentNReq; if (bh == CURRENT->bhtail) break; } buffer = acsi_buffer; pbuffer = phys_acsi_buffer; } else { unsigned long pendadr, pnewadr; pendadr = pbuffer + nsect*512; while( (bh = bh->b_reqnext) ) { pnewadr = virt_to_phys(bh->b_data); if (!STRAM_ADDR(pnewadr) || pendadr != pnewadr) break; nsect += bh->b_size >> 9; pendadr = pnewadr + bh->b_size; ++CurrentNReq; if (bh == CURRENT->bhtail) break; } } } else { if (!STRAM_ADDR(pbuffer)) { buffer = acsi_buffer; pbuffer = phys_acsi_buffer; if (nsect > ACSI_BUFFER_SECTORS) nsect = ACSI_BUFFER_SECTORS; } } CurrentBuffer = buffer; CurrentNSect = nsect; if (rq_data_dir(CURRENT) == WRITE) { CMDSET_TARG_LUN( write_cmd, target, lun ); CMDSET_BLOCK( write_cmd, block ); CMDSET_LEN( write_cmd, nsect ); if (buffer == acsi_buffer) copy_to_acsibuffer(); dma_cache_maintenance( pbuffer, nsect*512, 1 ); do_acsi = write_intr; if (!acsicmd_dma( write_cmd, buffer, nsect, 1, 1)) { do_acsi = NULL; printk( KERN_ERR "ACSI (write): Timeout in command block\n" ); bad_rw_intr(); goto repeat; } SET_TIMER(); return; } if (rq_data_dir(CURRENT) == READ) { CMDSET_TARG_LUN( read_cmd, target, lun ); CMDSET_BLOCK( read_cmd, block ); CMDSET_LEN( read_cmd, nsect ); do_acsi = read_intr; if (!acsicmd_dma( read_cmd, buffer, nsect, 0, 1)) { do_acsi = NULL; printk( KERN_ERR "ACSI (read): Timeout in command block\n" ); bad_rw_intr(); goto repeat; } SET_TIMER(); return; } panic("unknown ACSI command"); } /*********************************************************************** * * Misc functions: ioctl, open, release, check_change, ... * ***********************************************************************/ static int acsi_getgeo(struct block_device *bdev, struct hd_geometry *geo) { struct acsi_info_struct *aip = bdev->bd_disk->private_data; /* * Just fake some geometry here, it's nonsense anyway * To make it easy, use Adaptec's usual 64/32 mapping */ geo->heads = 64; geo->sectors = 32; geo->cylinders = aip->size >> 11; return 0; } static int acsi_ioctl( struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg ) { struct gendisk *disk = inode->i_bdev->bd_disk; struct acsi_info_struct *aip = disk->private_data; switch (cmd) { case SCSI_IOCTL_GET_IDLUN: /* SCSI compatible GET_IDLUN call to get target's ID and LUN number */ put_user( aip->target | (aip->lun << 8), &((Scsi_Idlun *) arg)->dev_id ); put_user( 0, &((Scsi_Idlun *) arg)->host_unique_id ); return 0; default: return -EINVAL; } } /* * Open a device, check for read-only and lock the medium if it is * removable. * * Changes by Martin Rogge, 9th Aug 1995: * Check whether check_disk_change (and therefore revalidate_acsidisk) * was successful. They fail when there is no medium in the drive. * * The problem of media being changed during an operation can be * ignored because of the prevent_removal code. * * Added check for the validity of the device number. * */ static int acsi_open( struct inode * inode, struct file * filp ) { struct gendisk *disk = inode->i_bdev->bd_disk; struct acsi_info_struct *aip = disk->private_data; if (aip->access_count == 0 && aip->removable) { #if 0 aip->changed = 1; /* safety first */ #endif check_disk_change( inode->i_bdev ); if (aip->changed) /* revalidate was not successful (no medium) */ return -ENXIO; acsi_prevent_removal(aip, 1); } aip->access_count++; if (filp && filp->f_mode) { check_disk_change( inode->i_bdev ); if (filp->f_mode & 2) { if (aip->read_only) { acsi_release( inode, filp ); return -EROFS; } } } return 0; } /* * Releasing a block device means we sync() it, so that it can safely * be forgotten about... */ static int acsi_release( struct inode * inode, struct file * file ) { struct gendisk *disk = inode->i_bdev->bd_disk; struct acsi_info_struct *aip = disk->private_data; if (--aip->access_count == 0 && aip->removable) acsi_prevent_removal(aip, 0); return( 0 ); } /* * Prevent or allow a media change for removable devices. */ static void acsi_prevent_removal(struct acsi_info_struct *aip, int flag) { stdma_lock( NULL, NULL ); CMDSET_TARG_LUN(pa_med_rem_cmd, aip->target, aip->lun); CMDSET_LEN( pa_med_rem_cmd, flag ); if (acsicmd_nodma(pa_med_rem_cmd, 0) && acsi_wait_for_IRQ(3*HZ)) acsi_getstatus(); /* Do not report errors -- some devices may not know this command. */ ENABLE_IRQ(); stdma_release(); } static int acsi_media_change(struct gendisk *disk) { struct acsi_info_struct *aip = disk->private_data; if (!aip->removable) return 0; if (aip->changed) /* We can be sure that the medium has been changed -- REQUEST * SENSE has reported this earlier. */ return 1; /* If the flag isn't set, make a test by reading block 0. * If errors happen, it seems to be better to say "changed"... */ stdma_lock( NULL, NULL ); CMDSET_TARG_LUN(read_cmd, aip->target, aip->lun); CMDSET_BLOCK( read_cmd, 0 ); CMDSET_LEN( read_cmd, 1 ); if (acsicmd_dma(read_cmd, acsi_buffer, 1, 0, 0) && acsi_wait_for_IRQ(3*HZ)) { if (acsi_getstatus()) { if (acsi_reqsense(acsi_buffer, aip->target, aip->lun)) { if (CARTRCH_STAT(aip, acsi_buffer)) aip->changed = 1; } else { printk( KERN_ERR "%s: REQUEST SENSE failed in test for " "medium change; assuming a change\n", disk->disk_name ); aip->changed = 1; } } } else { printk( KERN_ERR "%s: Test for medium changed timed out; " "assuming a change\n", disk->disk_name); aip->changed = 1; } ENABLE_IRQ(); stdma_release(); /* Now, after reading a block, the changed status is surely valid. */ return aip->changed; } static int acsi_change_blk_size( int target, int lun) { int i; for (i=0; i<12; i++) acsi_buffer[i] = 0; acsi_buffer[3] = 8; acsi_buffer[10] = 2; CMDSET_TARG_LUN( modeselect_cmd, target, lun); if (!acsicmd_dma( modeselect_cmd, acsi_buffer, 1,1,0) || !acsi_wait_for_IRQ( 3*HZ ) || acsi_getstatus() != 0 ) { return(0); } return(1); } static int acsi_mode_sense( int target, int lun, SENSE_DATA *sd ) { int page; CMDSET_TARG_LUN( modesense_cmd, target, lun ); for (page=0; page<4; page++) { modesense_cmd[2] = page; if (!acsicmd_dma( modesense_cmd, acsi_buffer, 1, 0, 0 ) || !acsi_wait_for_IRQ( 3*HZ ) || acsi_getstatus()) continue; /* read twice to jump over the second 16-byte border! */ udelay(300); if (acsi_wait_for_noIRQ( 20 ) && acsicmd_nodma( modesense_cmd, 0 ) && acsi_wait_for_IRQ( 3*HZ ) && acsi_getstatus() == 0) break; } if (page == 4) { return(0); } dma_cache_maintenance( phys_acsi_buffer, sizeof(SENSE_DATA), 0 ); *sd = *(SENSE_DATA *)acsi_buffer; /* Validity check, depending on type of data */ switch( SENSE_TYPE(*sd) ) { case SENSE_TYPE_ATARI: if (CAPACITY(*sd) == 0) goto invalid_sense; break; case SENSE_TYPE_SCSI: if (sd->scsi.descriptor_size != 8) goto invalid_sense; break; case SENSE_TYPE_UNKNOWN: printk( KERN_ERR "ACSI target %d, lun %d: Cannot interpret " "sense data\n", target, lun ); invalid_sense: #ifdef DEBUG { int i; printk( "Mode sense data for ACSI target %d, lun %d seem not valid:", target, lun ); for( i = 0; i < sizeof(SENSE_DATA); ++i ) printk( "%02x ", (unsigned char)acsi_buffer[i] ); printk( "\n" ); } #endif return( 0 ); } return( 1 ); } /******************************************************************* * * Initialization * ********************************************************************/ extern struct block_device_operations acsi_fops; static struct gendisk *acsi_gendisk[MAX_DEV]; #define MAX_SCSI_DEVICE_CODE 10 static const char *const scsi_device_types[MAX_SCSI_DEVICE_CODE] = { "Direct-Access ", "Sequential-Access", "Printer ", "Processor ", "WORM ", "CD-ROM ", "Scanner ", "Optical Device ", "Medium Changer ", "Communications " }; static void print_inquiry(unsigned char *data) { int i; printk(KERN_INFO " Vendor: "); for (i = 8; i < 16; i++) { if (data[i] >= 0x20 && i < data[4] + 5) printk("%c", data[i]); else printk(" "); } printk(" Model: "); for (i = 16; i < 32; i++) { if (data[i] >= 0x20 && i < data[4] + 5) printk("%c", data[i]); else printk(" "); } printk(" Rev: "); for (i = 32; i < 36; i++) { if (data[i] >= 0x20 && i < data[4] + 5) printk("%c", data[i]); else printk(" "); } printk("\n"); i = data[0] & 0x1f; printk(KERN_INFO " Type: %s ", (i < MAX_SCSI_DEVICE_CODE ? scsi_device_types[i] : "Unknown ")); printk(" ANSI SCSI revision: %02x", data[2] & 0x07); if ((data[2] & 0x07) == 1 && (data[3] & 0x0f) == 1) printk(" CCS\n"); else printk("\n"); } /* * Changes by Martin Rogge, 9th Aug 1995: * acsi_devinit has been taken out of acsi_geninit, because it needs * to be called from revalidate_acsidisk. The result of request sense * is now checked for DRIVE NOT READY. * * The structure *aip is only valid when acsi_devinit returns * DEV_SUPPORTED. * */ #define DEV_NONE 0 #define DEV_UNKNOWN 1 #define DEV_SUPPORTED 2 #define DEV_SLM 3 static int acsi_devinit(struct acsi_info_struct *aip) { int status, got_inquiry; SENSE_DATA sense; unsigned char reqsense, extsense; /*****************************************************************/ /* Do a TEST UNIT READY command to test the presence of a device */ /*****************************************************************/ CMDSET_TARG_LUN(tur_cmd, aip->target, aip->lun); if (!acsicmd_nodma(tur_cmd, 0)) { /* timed out -> no device here */ #ifdef DEBUG_DETECT printk("target %d lun %d: timeout\n", aip->target, aip->lun); #endif return DEV_NONE; } /*************************/ /* Read the ACSI status. */ /*************************/ status = acsi_getstatus(); if (status) { if (status == 0x12) { /* The SLM printer should be the only device that * responds with the error code in the status byte. In * correct status bytes, bit 4 is never set. */ printk( KERN_INFO "Detected SLM printer at id %d lun %d\n", aip->target, aip->lun); return DEV_SLM; } /* ignore CHECK CONDITION, since some devices send a UNIT ATTENTION */ if ((status & 0x1e) != 0x2) { #ifdef DEBUG_DETECT printk("target %d lun %d: status %d\n", aip->target, aip->lun, status); #endif return DEV_UNKNOWN; } } /*******************************/ /* Do a REQUEST SENSE command. */ /*******************************/ if (!acsi_reqsense(acsi_buffer, aip->target, aip->lun)) { printk( KERN_WARNING "acsi_reqsense failed\n"); acsi_buffer[0] = 0; acsi_buffer[2] = UNIT_ATTENTION; } reqsense = acsi_buffer[0]; extsense = acsi_buffer[2] & 0xf; if (status) { if ((reqsense & 0x70) == 0x70) { /* extended sense */ if (extsense != UNIT_ATTENTION && extsense != NOT_READY) { #ifdef DEBUG_DETECT printk("target %d lun %d: extended sense %d\n", aip->target, aip->lun, extsense); #endif return DEV_UNKNOWN; } } else { if (reqsense & 0x7f) { #ifdef DEBUG_DETECT printk("target %d lun %d: sense %d\n", aip->target, aip->lun, reqsense); #endif return DEV_UNKNOWN; } } } else if (reqsense == 0x4) { /* SH204 Bug workaround */ #ifdef DEBUG_DETECT printk("target %d lun %d status=0 sense=4\n", aip->target, aip->lun); #endif return DEV_UNKNOWN; } /***********************************************************/ /* Do an INQUIRY command to get more infos on this device. */ /***********************************************************/ /* Assume default values */ aip->removable = 1; aip->read_only = 0; aip->old_atari_disk = 0; aip->changed = (extsense == NOT_READY); /* medium inserted? */ aip->size = DEFAULT_SIZE; got_inquiry = 0; /* Fake inquiry result for old atari disks */ memcpy(acsi_buffer, "\000\000\001\000 Adaptec 40xx" " ", 40); CMDSET_TARG_LUN(inquiry_cmd, aip->target, aip->lun); if (acsicmd_dma(inquiry_cmd, acsi_buffer, 1, 0, 0) && acsi_getstatus() == 0) { acsicmd_nodma(inquiry_cmd, 0); acsi_getstatus(); dma_cache_maintenance( phys_acsi_buffer, 256, 0 ); got_inquiry = 1; aip->removable = !!(acsi_buffer[1] & 0x80); } if (aip->type == NONE) /* only at boot time */ print_inquiry(acsi_buffer); switch(acsi_buffer[0]) { case TYPE_DISK: aip->type = HARDDISK; break; case TYPE_ROM: aip->type = CDROM; aip->read_only = 1; break; default: return DEV_UNKNOWN; } /****************************/ /* Do a MODE SENSE command. */ /****************************/ if (!acsi_mode_sense(aip->target, aip->lun, &sense)) { printk( KERN_WARNING "No mode sense data.\n" ); return DEV_UNKNOWN; } if ((SECTOR_SIZE(sense) != 512) && ((aip->type != CDROM) || !acsi_change_blk_size(aip->target, aip->lun) || !acsi_mode_sense(aip->target, aip->lun, &sense) || (SECTOR_SIZE(sense) != 512))) { printk( KERN_WARNING "Sector size != 512 not supported.\n" ); return DEV_UNKNOWN; } /* There are disks out there that claim to have 0 sectors... */ if (CAPACITY(sense)) aip->size = CAPACITY(sense); /* else keep DEFAULT_SIZE */ if (!got_inquiry && SENSE_TYPE(sense) == SENSE_TYPE_ATARI) { /* If INQUIRY failed and the sense data suggest an old * Atari disk (SH20x, Megafile), the disk is not removable */ aip->removable = 0; aip->old_atari_disk = 1; } /******************/ /* We've done it. */ /******************/ return DEV_SUPPORTED; } EXPORT_SYMBOL(acsi_delay_start); EXPORT_SYMBOL(acsi_delay_end); EXPORT_SYMBOL(acsi_wait_for_IRQ); EXPORT_SYMBOL(acsi_wait_for_noIRQ); EXPORT_SYMBOL(acsicmd_nodma); EXPORT_SYMBOL(acsi_getstatus); EXPORT_SYMBOL(acsi_buffer); EXPORT_SYMBOL(phys_acsi_buffer); #ifdef CONFIG_ATARI_SLM_MODULE void acsi_attach_SLMs( int (*attach_func)( int, int ) ); EXPORT_SYMBOL(acsi_extstatus); EXPORT_SYMBOL(acsi_end_extstatus); EXPORT_SYMBOL(acsi_extcmd); EXPORT_SYMBOL(acsi_attach_SLMs); /* to remember IDs of SLM devices, SLM module is loaded later * (index is target#, contents is lun#, -1 means "no SLM") */ int SLM_devices[8]; #endif static struct block_device_operations acsi_fops = { .owner = THIS_MODULE, .open = acsi_open, .release = acsi_release, .ioctl = acsi_ioctl, .getgeo = acsi_getgeo, .media_changed = acsi_media_change, .revalidate_disk= acsi_revalidate, }; #ifdef CONFIG_ATARI_SLM_MODULE /* call attach_slm() for each device that is a printer; needed for init of SLM * driver as a module, since it's not yet present if acsi.c is inited and thus * the bus gets scanned. */ void acsi_attach_SLMs( int (*attach_func)( int, int ) ) { int i, n = 0; for( i = 0; i < 8; ++i ) if (SLM_devices[i] >= 0) n += (*attach_func)( i, SLM_devices[i] ); printk( KERN_INFO "Found %d SLM printer(s) total.\n", n ); } #endif /* CONFIG_ATARI_SLM_MODULE */ int acsi_init( void ) { int err = 0; int i, target, lun; struct acsi_info_struct *aip; #ifdef CONFIG_ATARI_SLM int n_slm = 0; #endif if (!MACH_IS_ATARI || !ATARIHW_PRESENT(ACSI)) return 0; if (register_blkdev(ACSI_MAJOR, "ad")) { err = -EBUSY; goto out1; } if (!(acsi_buffer = (char *)atari_stram_alloc(ACSI_BUFFER_SIZE, "acsi"))) { err = -ENOMEM; printk( KERN_ERR "Unable to get ACSI ST-Ram buffer.\n" ); goto out2; } phys_acsi_buffer = virt_to_phys( acsi_buffer ); STramMask = ATARIHW_PRESENT(EXTD_DMA) ? 0x00000000 : 0xff000000; acsi_queue = blk_init_queue(do_acsi_request, &acsi_lock); if (!acsi_queue) { err = -ENOMEM; goto out2a; } #ifdef CONFIG_ATARI_SLM err = slm_init(); #endif if (err) goto out3; printk( KERN_INFO "Probing ACSI devices:\n" ); NDevices = 0; #ifdef CONFIG_ATARI_SLM_MODULE for( i = 0; i < 8; ++i ) SLM_devices[i] = -1; #endif stdma_lock(NULL, NULL); for (target = 0; target < 8 && NDevices < MAX_DEV; ++target) { lun = 0; do { aip = &acsi_info[NDevices]; aip->type = NONE; aip->target = target; aip->lun = lun; i = acsi_devinit(aip); switch (i) { case DEV_SUPPORTED: printk( KERN_INFO "Detected "); switch (aip->type) { case HARDDISK: printk("disk"); break; case CDROM: printk("cdrom"); break; default: } printk(" ad%c at id %d lun %d ", 'a' + NDevices, target, lun); if (aip->removable) printk("(removable) "); if (aip->read_only) printk("(read-only) "); if (aip->size == DEFAULT_SIZE) printk(" unkown size, using default "); printk("%ld MByte\n", (aip->size*512+1024*1024/2)/(1024*1024)); NDevices++; break; case DEV_SLM: #ifdef CONFIG_ATARI_SLM n_slm += attach_slm( target, lun ); break; #endif #ifdef CONFIG_ATARI_SLM_MODULE SLM_devices[target] = lun; break; #endif /* neither of the above: fall through to unknown device */ case DEV_UNKNOWN: printk( KERN_INFO "Detected unsupported device at " "id %d lun %d\n", target, lun); break; } } #ifdef CONFIG_ACSI_MULTI_LUN while (i != DEV_NONE && ++lun < MAX_LUN); #else while (0); #endif } /* reenable interrupt */ ENABLE_IRQ(); stdma_release(); #ifndef CONFIG_ATARI_SLM printk( KERN_INFO "Found %d ACSI device(s) total.\n", NDevices ); #else printk( KERN_INFO "Found %d ACSI device(s) and %d SLM printer(s) total.\n", NDevices, n_slm ); #endif err = -ENOMEM; for( i = 0; i < NDevices; ++i ) { acsi_gendisk[i] = alloc_disk(16); if (!acsi_gendisk[i]) goto out4; } for( i = 0; i < NDevices; ++i ) { struct gendisk *disk = acsi_gendisk[i]; sprintf(disk->disk_name, "ad%c", 'a'+i); aip = &acsi_info[NDevices]; disk->major = ACSI_MAJOR; disk->first_minor = i << 4; if (acsi_info[i].type != HARDDISK) disk->minors = 1; disk->fops = &acsi_fops; disk->private_data = &acsi_info[i]; set_capacity(disk, acsi_info[i].size); disk->queue = acsi_queue; add_disk(disk); } return 0; out4: while (i--) put_disk(acsi_gendisk[i]); out3: blk_cleanup_queue(acsi_queue); out2a: atari_stram_free( acsi_buffer ); out2: unregister_blkdev( ACSI_MAJOR, "ad" ); out1: return err; } #ifdef MODULE MODULE_LICENSE("GPL"); int init_module(void) { int err; if ((err = acsi_init())) return( err ); printk( KERN_INFO "ACSI driver loaded as module.\n"); return( 0 ); } void cleanup_module(void) { int i; del_timer( &acsi_timer ); blk_cleanup_queue(acsi_queue); atari_stram_free( acsi_buffer ); if (unregister_blkdev( ACSI_MAJOR, "ad" ) != 0) printk( KERN_ERR "acsi: cleanup_module failed\n"); for (i = 0; i < NDevices; i++) { del_gendisk(acsi_gendisk[i]); put_disk(acsi_gendisk[i]); } } #endif /* * This routine is called to flush all partitions and partition tables * for a changed scsi disk, and then re-read the new partition table. * If we are revalidating a disk because of a media change, then we * enter with usage == 0. If we are using an ioctl, we automatically have * usage == 1 (we need an open channel to use an ioctl :-), so this * is our limit. * * Changes by Martin Rogge, 9th Aug 1995: * got cd-roms to work by calling acsi_devinit. There are only two problems: * First, if there is no medium inserted, the status will remain "changed". * That is no problem at all, but our design of three-valued logic (medium * changed, medium not changed, no medium inserted). * Secondly the check could fail completely and the drive could deliver * nonsensical data, which could mess up the acsi_info[] structure. In * that case we try to make the entry safe. * */ static int acsi_revalidate(struct gendisk *disk) { struct acsi_info_struct *aip = disk->private_data; stdma_lock( NULL, NULL ); if (acsi_devinit(aip) != DEV_SUPPORTED) { printk( KERN_ERR "ACSI: revalidate failed for target %d lun %d\n", aip->target, aip->lun); aip->size = 0; aip->read_only = 1; aip->removable = 1; aip->changed = 1; /* next acsi_open will try again... */ } ENABLE_IRQ(); stdma_release(); set_capacity(disk, aip->size); return 0; }