/* * sd.c Copyright (C) 1992 Drew Eckhardt * Copyright (C) 1993, 1994, 1995 Eric Youngdale * * Linux scsi disk driver * Initial versions: Drew Eckhardt * Subsequent revisions: Eric Youngdale * * * * Modified by Eric Youngdale ericy@cais.com to * add scatter-gather, multiple outstanding request, and other * enhancements. * * Modified by Eric Youngdale eric@aib.com to support loadable * low-level scsi drivers. */ #include #include #include #include #include #include #include #define MAJOR_NR SCSI_DISK_MAJOR #include "../block/blk.h" #include "scsi.h" #include "hosts.h" #include "sd.h" #include "scsi_ioctl.h" #include "constants.h" #include /* static const char RCSid[] = "$Header:"; */ #define MAX_RETRIES 5 /* * Time out in seconds for disks and Magneto-opticals (which are slower). */ #define SD_TIMEOUT 600 #define SD_MOD_TIMEOUT 750 #define CLUSTERABLE_DEVICE(SC) (SC->host->hostt->use_clustering && \ SC->device->type != TYPE_MOD) struct hd_struct * sd; int revalidate_scsidisk(int dev, int maxusage); Scsi_Disk * rscsi_disks = NULL; static int * sd_sizes; static int * sd_blocksizes; static int * sd_hardsizes; /* Hardware sector size */ extern int sd_ioctl(struct inode *, struct file *, unsigned int, unsigned long); static int check_scsidisk_media_change(dev_t); static int fop_revalidate_scsidisk(dev_t); static sd_init_onedisk(int); static void requeue_sd_request (Scsi_Cmnd * SCpnt); static void sd_init(void); static void sd_finish(void); static int sd_attach(Scsi_Device *); static int sd_detect(Scsi_Device *); static void sd_detach(Scsi_Device *); struct Scsi_Device_Template sd_template = {NULL, "disk", "sd", TYPE_DISK, SCSI_DISK_MAJOR, 0, 0, 0, 1, sd_detect, sd_init, sd_finish, sd_attach, sd_detach}; static int sd_open(struct inode * inode, struct file * filp) { int target; target = DEVICE_NR(MINOR(inode->i_rdev)); if(target >= sd_template.dev_max || !rscsi_disks[target].device) return -ENXIO; /* No such device */ /* Make sure that only one process can do a check_change_disk at one time. This is also used to lock out further access when the partition table is being re-read. */ while (rscsi_disks[target].device->busy) barrier(); if(rscsi_disks[target].device->removable) { check_disk_change(inode->i_rdev); if(!rscsi_disks[target].device->access_count) sd_ioctl(inode, NULL, SCSI_IOCTL_DOORLOCK, 0); }; /* * See if we are requesting a non-existent partition. Do this * after checking for disk change. */ if(sd_sizes[MINOR(inode->i_rdev)] == 0) return -ENXIO; rscsi_disks[target].device->access_count++; if (rscsi_disks[target].device->host->hostt->usage_count) (*rscsi_disks[target].device->host->hostt->usage_count)++; return 0; } static void sd_release(struct inode * inode, struct file * file) { int target; sync_dev(inode->i_rdev); target = DEVICE_NR(MINOR(inode->i_rdev)); rscsi_disks[target].device->access_count--; if (rscsi_disks[target].device->host->hostt->usage_count) (*rscsi_disks[target].device->host->hostt->usage_count)--; if(rscsi_disks[target].device->removable) { if(!rscsi_disks[target].device->access_count) sd_ioctl(inode, NULL, SCSI_IOCTL_DOORUNLOCK, 0); }; } static void sd_geninit(void); static struct file_operations sd_fops = { NULL, /* lseek - default */ block_read, /* read - general block-dev read */ block_write, /* write - general block-dev write */ NULL, /* readdir - bad */ NULL, /* select */ sd_ioctl, /* ioctl */ NULL, /* mmap */ sd_open, /* open code */ sd_release, /* release */ block_fsync, /* fsync */ NULL, /* fasync */ check_scsidisk_media_change, /* Disk change */ fop_revalidate_scsidisk /* revalidate */ }; static struct gendisk sd_gendisk = { MAJOR_NR, /* Major number */ "sd", /* Major name */ 4, /* Bits to shift to get real from partition */ 1 << 4, /* Number of partitions per real */ 0, /* maximum number of real */ sd_geninit, /* init function */ NULL, /* hd struct */ NULL, /* block sizes */ 0, /* number */ NULL, /* internal */ NULL /* next */ }; static void sd_geninit (void) { int i; for (i = 0; i < sd_template.dev_max; ++i) if(rscsi_disks[i].device) sd[i << 4].nr_sects = rscsi_disks[i].capacity; #if 0 /* No longer needed - we keep track of this as we attach/detach */ sd_gendisk.nr_real = sd_template.dev_max; #endif } /* rw_intr is the interrupt routine for the device driver. It will be notified on the end of a SCSI read / write, and will take on of several actions based on success or failure. */ static void rw_intr (Scsi_Cmnd *SCpnt) { int result = SCpnt->result; int this_count = SCpnt->bufflen >> 9; #ifdef DEBUG printk("sd%c : rw_intr(%d, %d)\n", 'a' + MINOR(SCpnt->request.dev), SCpnt->host->host_no, result); #endif /* First case : we assume that the command succeeded. One of two things will happen here. Either we will be finished, or there will be more sectors that we were unable to read last time. */ if (!result) { #ifdef DEBUG printk("sd%c : %d sectors remain.\n", 'a' + MINOR(SCpnt->request.dev), SCpnt->request.nr_sectors); printk("use_sg is %d\n ",SCpnt->use_sg); #endif if (SCpnt->use_sg) { struct scatterlist * sgpnt; int i; sgpnt = (struct scatterlist *) SCpnt->buffer; for(i=0; iuse_sg; i++) { #ifdef DEBUG printk(":%x %x %d\n",sgpnt[i].alt_address, sgpnt[i].address, sgpnt[i].length); #endif if (sgpnt[i].alt_address) { if (SCpnt->request.cmd == READ) memcpy(sgpnt[i].alt_address, sgpnt[i].address, sgpnt[i].length); scsi_free(sgpnt[i].address, sgpnt[i].length); }; }; scsi_free(SCpnt->buffer, SCpnt->sglist_len); /* Free list of scatter-gather pointers */ } else { if (SCpnt->buffer != SCpnt->request.buffer) { #ifdef DEBUG printk("nosg: %x %x %d\n",SCpnt->request.buffer, SCpnt->buffer, SCpnt->bufflen); #endif if (SCpnt->request.cmd == READ) memcpy(SCpnt->request.buffer, SCpnt->buffer, SCpnt->bufflen); scsi_free(SCpnt->buffer, SCpnt->bufflen); }; }; /* * If multiple sectors are requested in one buffer, then * they will have been finished off by the first command. If * not, then we have a multi-buffer command. */ if (SCpnt->request.nr_sectors > this_count) { SCpnt->request.errors = 0; if (!SCpnt->request.bh) { #ifdef DEBUG printk("sd%c : handling page request, no buffer\n", 'a' + MINOR(SCpnt->request.dev)); #endif /* The SCpnt->request.nr_sectors field is always done in 512 byte sectors, even if this really isn't the case. */ panic("sd.c: linked page request (%lx %x)", SCpnt->request.sector, this_count); } } SCpnt = end_scsi_request(SCpnt, 1, this_count); requeue_sd_request(SCpnt); return; } /* Free up any indirection buffers we allocated for DMA purposes. */ if (SCpnt->use_sg) { struct scatterlist * sgpnt; int i; sgpnt = (struct scatterlist *) SCpnt->buffer; for(i=0; iuse_sg; i++) { #ifdef DEBUG printk("err: %x %x %d\n",SCpnt->request.buffer, SCpnt->buffer, SCpnt->bufflen); #endif if (sgpnt[i].alt_address) { scsi_free(sgpnt[i].address, sgpnt[i].length); }; }; scsi_free(SCpnt->buffer, SCpnt->sglist_len); /* Free list of scatter-gather pointers */ } else { #ifdef DEBUG printk("nosgerr: %x %x %d\n",SCpnt->request.buffer, SCpnt->buffer, SCpnt->bufflen); #endif if (SCpnt->buffer != SCpnt->request.buffer) scsi_free(SCpnt->buffer, SCpnt->bufflen); }; /* Now, if we were good little boys and girls, Santa left us a request sense buffer. We can extract information from this, so we can choose a block to remap, etc. */ if (driver_byte(result) != 0) { if (suggestion(result) == SUGGEST_REMAP) { #ifdef REMAP /* Not yet implemented. A read will fail after being remapped, a write will call the strategy routine again. */ if rscsi_disks[DEVICE_NR(SCpnt->request.dev)].remap { result = 0; } else #endif } if ((SCpnt->sense_buffer[0] & 0x7f) == 0x70) { if ((SCpnt->sense_buffer[2] & 0xf) == UNIT_ATTENTION) { if(rscsi_disks[DEVICE_NR(SCpnt->request.dev)].device->removable) { /* detected disc change. set a bit and quietly refuse */ /* further access. */ rscsi_disks[DEVICE_NR(SCpnt->request.dev)].device->changed = 1; SCpnt = end_scsi_request(SCpnt, 0, this_count); requeue_sd_request(SCpnt); return; } } } /* If we had an ILLEGAL REQUEST returned, then we may have performed an unsupported command. The only thing this should be would be a ten byte read where only a six byte read was supported. Also, on a system where READ CAPACITY failed, we have have read past the end of the disk. */ if (SCpnt->sense_buffer[2] == ILLEGAL_REQUEST) { if (rscsi_disks[DEVICE_NR(SCpnt->request.dev)].ten) { rscsi_disks[DEVICE_NR(SCpnt->request.dev)].ten = 0; requeue_sd_request(SCpnt); result = 0; } else { } } } /* driver byte != 0 */ if (result) { printk("SCSI disk error : host %d id %d lun %d return code = %x\n", rscsi_disks[DEVICE_NR(SCpnt->request.dev)].device->host->host_no, rscsi_disks[DEVICE_NR(SCpnt->request.dev)].device->id, rscsi_disks[DEVICE_NR(SCpnt->request.dev)].device->lun, result); if (driver_byte(result) & DRIVER_SENSE) print_sense("sd", SCpnt); SCpnt = end_scsi_request(SCpnt, 0, SCpnt->request.current_nr_sectors); requeue_sd_request(SCpnt); return; } } /* requeue_sd_request() is the request handler function for the sd driver. Its function in life is to take block device requests, and translate them to SCSI commands. */ static void do_sd_request (void) { Scsi_Cmnd * SCpnt = NULL; struct request * req = NULL; unsigned long flags; int flag = 0; save_flags(flags); while (1==1){ cli(); if (CURRENT != NULL && CURRENT->dev == -1) { restore_flags(flags); return; }; INIT_SCSI_REQUEST; /* We have to be careful here. allocate_device will get a free pointer, but there is no guarantee that it is queueable. In normal usage, we want to call this, because other types of devices may have the host all tied up, and we want to make sure that we have at least one request pending for this type of device. We can also come through here while servicing an interrupt, because of the need to start another command. If we call allocate_device more than once, then the system can wedge if the command is not queueable. The request_queueable function is safe because it checks to make sure that the host is able to take another command before it returns a pointer. */ if (flag++ == 0) SCpnt = allocate_device(&CURRENT, rscsi_disks[DEVICE_NR(MINOR(CURRENT->dev))].device, 0); else SCpnt = NULL; /* * The following restore_flags leads to latency problems. FIXME. * Using a "sti()" gets rid of the latency problems but causes * race conditions and crashes. */ restore_flags(flags); /* This is a performance enhancement. We dig down into the request list and try and find a queueable request (i.e. device not busy, and host able to accept another command. If we find one, then we queue it. This can make a big difference on systems with more than one disk drive. We want to have the interrupts off when monkeying with the request list, because otherwise the kernel might try and slip in a request in between somewhere. */ if (!SCpnt && sd_template.nr_dev > 1){ struct request *req1; req1 = NULL; cli(); req = CURRENT; while(req){ SCpnt = request_queueable(req, rscsi_disks[DEVICE_NR(MINOR(req->dev))].device); if(SCpnt) break; req1 = req; req = req->next; }; if (SCpnt && req->dev == -1) { if (req == CURRENT) CURRENT = CURRENT->next; else req1->next = req->next; }; restore_flags(flags); }; if (!SCpnt) return; /* Could not find anything to do */ /* Queue command */ requeue_sd_request(SCpnt); }; /* While */ } static void requeue_sd_request (Scsi_Cmnd * SCpnt) { int dev, block, this_count; unsigned char cmd[10]; int bounce_size, contiguous; int max_sg; struct buffer_head * bh, *bhp; char * buff, *bounce_buffer; repeat: if(!SCpnt || SCpnt->request.dev <= 0) { do_sd_request(); return; } dev = MINOR(SCpnt->request.dev); block = SCpnt->request.sector; this_count = 0; #ifdef DEBUG printk("Doing sd request, dev = %d, block = %d\n", dev, block); #endif if (dev >= (sd_template.dev_max << 4) || !rscsi_disks[DEVICE_NR(dev)].device || block + SCpnt->request.nr_sectors > sd[dev].nr_sects) { SCpnt = end_scsi_request(SCpnt, 0, SCpnt->request.nr_sectors); goto repeat; } block += sd[dev].start_sect; dev = DEVICE_NR(dev); if (rscsi_disks[dev].device->changed) { /* * quietly refuse to do anything to a changed disc until the changed bit has been reset */ /* printk("SCSI disk has been changed. Prohibiting further I/O.\n"); */ SCpnt = end_scsi_request(SCpnt, 0, SCpnt->request.nr_sectors); goto repeat; } #ifdef DEBUG printk("sd%c : real dev = /dev/sd%c, block = %d\n", 'a' + MINOR(SCpnt->request.dev), dev, block); #endif /* * If we have a 1K hardware sectorsize, prevent access to single * 512 byte sectors. In theory we could handle this - in fact * the scsi cdrom driver must be able to handle this because * we typically use 1K blocksizes, and cdroms typically have * 2K hardware sectorsizes. Of course, things are simpler * with the cdrom, since it is read-only. For performance * reasons, the filesystems should be able to handle this * and not force the scsi disk driver to use bounce buffers * for this. */ if (rscsi_disks[dev].sector_size == 1024) if((block & 1) || (SCpnt->request.nr_sectors & 1)) { printk("sd.c:Bad block number requested"); SCpnt = end_scsi_request(SCpnt, 0, SCpnt->request.nr_sectors); goto repeat; } switch (SCpnt->request.cmd) { case WRITE : if (!rscsi_disks[dev].device->writeable) { SCpnt = end_scsi_request(SCpnt, 0, SCpnt->request.nr_sectors); goto repeat; } cmd[0] = WRITE_6; break; case READ : cmd[0] = READ_6; break; default : panic ("Unknown sd command %d\n", SCpnt->request.cmd); } SCpnt->this_count = 0; /* If the host adapter can deal with very large scatter-gather requests, it is a waste of time to cluster */ contiguous = (!CLUSTERABLE_DEVICE(SCpnt) ? 0 :1); bounce_buffer = NULL; bounce_size = (SCpnt->request.nr_sectors << 9); /* First see if we need a bounce buffer for this request. If we do, make sure that we can allocate a buffer. Do not waste space by allocating a bounce buffer if we are straddling the 16Mb line */ if (contiguous && SCpnt->request.bh && ((long) SCpnt->request.bh->b_data) + (SCpnt->request.nr_sectors << 9) - 1 > ISA_DMA_THRESHOLD && SCpnt->host->unchecked_isa_dma) { if(((long) SCpnt->request.bh->b_data) > ISA_DMA_THRESHOLD) bounce_buffer = (char *) scsi_malloc(bounce_size); if(!bounce_buffer) contiguous = 0; }; if(contiguous && SCpnt->request.bh && SCpnt->request.bh->b_reqnext) for(bh = SCpnt->request.bh, bhp = bh->b_reqnext; bhp; bh = bhp, bhp = bhp->b_reqnext) { if(!CONTIGUOUS_BUFFERS(bh,bhp)) { if(bounce_buffer) scsi_free(bounce_buffer, bounce_size); contiguous = 0; break; } }; if (!SCpnt->request.bh || contiguous) { /* case of page request (i.e. raw device), or unlinked buffer */ this_count = SCpnt->request.nr_sectors; buff = SCpnt->request.buffer; SCpnt->use_sg = 0; } else if (SCpnt->host->sg_tablesize == 0 || (need_isa_buffer && dma_free_sectors <= 10)) { /* Case of host adapter that cannot scatter-gather. We also come here if we are running low on DMA buffer memory. We set a threshold higher than that we would need for this request so we leave room for other requests. Even though we would not need it all, we need to be conservative, because if we run low enough we have no choice but to panic. */ if (SCpnt->host->sg_tablesize != 0 && need_isa_buffer && dma_free_sectors <= 10) printk("Warning: SCSI DMA buffer space running low. Using non scatter-gather I/O.\n"); this_count = SCpnt->request.current_nr_sectors; buff = SCpnt->request.buffer; SCpnt->use_sg = 0; } else { /* Scatter-gather capable host adapter */ struct scatterlist * sgpnt; int count, this_count_max; int counted; bh = SCpnt->request.bh; this_count = 0; this_count_max = (rscsi_disks[dev].ten ? 0xffff : 0xff); count = 0; bhp = NULL; while(bh) { if ((this_count + (bh->b_size >> 9)) > this_count_max) break; if(!bhp || !CONTIGUOUS_BUFFERS(bhp,bh) || !CLUSTERABLE_DEVICE(SCpnt) || (SCpnt->host->unchecked_isa_dma && ((unsigned long) bh->b_data-1) == ISA_DMA_THRESHOLD)) { if (count < SCpnt->host->sg_tablesize) count++; else break; }; this_count += (bh->b_size >> 9); bhp = bh; bh = bh->b_reqnext; }; #if 0 if(SCpnt->host->unchecked_isa_dma && ((unsigned int) SCpnt->request.bh->b_data-1) == ISA_DMA_THRESHOLD) count--; #endif SCpnt->use_sg = count; /* Number of chains */ count = 512;/* scsi_malloc can only allocate in chunks of 512 bytes*/ while( count < (SCpnt->use_sg * sizeof(struct scatterlist))) count = count << 1; SCpnt->sglist_len = count; max_sg = count / sizeof(struct scatterlist); if(SCpnt->host->sg_tablesize < max_sg) max_sg = SCpnt->host->sg_tablesize; sgpnt = (struct scatterlist * ) scsi_malloc(count); memset(sgpnt, 0, count); /* Zero so it is easy to fill */ if (!sgpnt) { printk("Warning - running *really* short on DMA buffers\n"); SCpnt->use_sg = 0; /* No memory left - bail out */ this_count = SCpnt->request.current_nr_sectors; buff = SCpnt->request.buffer; } else { buff = (char *) sgpnt; counted = 0; for(count = 0, bh = SCpnt->request.bh, bhp = bh->b_reqnext; count < SCpnt->use_sg && bh; count++, bh = bhp) { bhp = bh->b_reqnext; if(!sgpnt[count].address) sgpnt[count].address = bh->b_data; sgpnt[count].length += bh->b_size; counted += bh->b_size >> 9; if (((long) sgpnt[count].address) + sgpnt[count].length - 1 > ISA_DMA_THRESHOLD && (SCpnt->host->unchecked_isa_dma) && !sgpnt[count].alt_address) { sgpnt[count].alt_address = sgpnt[count].address; /* We try and avoid exhausting the DMA pool, since it is easier to control usage here. In other places we might have a more pressing need, and we would be screwed if we ran out */ if(dma_free_sectors < (sgpnt[count].length >> 9) + 10) { sgpnt[count].address = NULL; } else { sgpnt[count].address = (char *) scsi_malloc(sgpnt[count].length); }; /* If we start running low on DMA buffers, we abort the scatter-gather operation, and free all of the memory we have allocated. We want to ensure that all scsi operations are able to do at least a non-scatter/gather operation */ if(sgpnt[count].address == NULL){ /* Out of dma memory */ #if 0 printk("Warning: Running low on SCSI DMA buffers"); /* Try switching back to a non scatter-gather operation. */ while(--count >= 0){ if(sgpnt[count].alt_address) scsi_free(sgpnt[count].address, sgpnt[count].length); }; this_count = SCpnt->request.current_nr_sectors; buff = SCpnt->request.buffer; SCpnt->use_sg = 0; scsi_free(sgpnt, SCpnt->sglist_len); #endif SCpnt->use_sg = count; this_count = counted -= bh->b_size >> 9; break; }; }; /* Only cluster buffers if we know that we can supply DMA buffers large enough to satisfy the request. Do not cluster a new request if this would mean that we suddenly need to start using DMA bounce buffers */ if(bhp && CONTIGUOUS_BUFFERS(bh,bhp) && CLUSTERABLE_DEVICE(SCpnt)) { char * tmp; if (((long) sgpnt[count].address) + sgpnt[count].length + bhp->b_size - 1 > ISA_DMA_THRESHOLD && (SCpnt->host->unchecked_isa_dma) && !sgpnt[count].alt_address) continue; if(!sgpnt[count].alt_address) {count--; continue; } if(dma_free_sectors > 10) tmp = (char *) scsi_malloc(sgpnt[count].length + bhp->b_size); else { tmp = NULL; max_sg = SCpnt->use_sg; }; if(tmp){ scsi_free(sgpnt[count].address, sgpnt[count].length); sgpnt[count].address = tmp; count--; continue; }; /* If we are allowed another sg chain, then increment counter so we can insert it. Otherwise we will end up truncating */ if (SCpnt->use_sg < max_sg) SCpnt->use_sg++; }; /* contiguous buffers */ }; /* for loop */ this_count = counted; /* This is actually how many we are going to transfer */ if(count < SCpnt->use_sg || SCpnt->use_sg > SCpnt->host->sg_tablesize){ bh = SCpnt->request.bh; printk("Use sg, count %d %x %d\n", SCpnt->use_sg, count, dma_free_sectors); printk("maxsg = %x, counted = %d this_count = %d\n", max_sg, counted, this_count); while(bh){ printk("[%p %lx] ", bh->b_data, bh->b_size); bh = bh->b_reqnext; }; if(SCpnt->use_sg < 16) for(count=0; countuse_sg; count++) printk("{%d:%p %p %d} ", count, sgpnt[count].address, sgpnt[count].alt_address, sgpnt[count].length); panic("Ooops"); }; if (SCpnt->request.cmd == WRITE) for(count=0; countuse_sg; count++) if(sgpnt[count].alt_address) memcpy(sgpnt[count].address, sgpnt[count].alt_address, sgpnt[count].length); }; /* Able to malloc sgpnt */ }; /* Host adapter capable of scatter-gather */ /* Now handle the possibility of DMA to addresses > 16Mb */ if(SCpnt->use_sg == 0){ if (((long) buff) + (this_count << 9) - 1 > ISA_DMA_THRESHOLD && (SCpnt->host->unchecked_isa_dma)) { if(bounce_buffer) buff = bounce_buffer; else buff = (char *) scsi_malloc(this_count << 9); if(buff == NULL) { /* Try backing off a bit if we are low on mem*/ this_count = SCpnt->request.current_nr_sectors; buff = (char *) scsi_malloc(this_count << 9); if(!buff) panic("Ran out of DMA buffers."); }; if (SCpnt->request.cmd == WRITE) memcpy(buff, (char *)SCpnt->request.buffer, this_count << 9); }; }; #ifdef DEBUG printk("sd%c : %s %d/%d 512 byte blocks.\n", 'a' + MINOR(SCpnt->request.dev), (SCpnt->request.cmd == WRITE) ? "writing" : "reading", this_count, SCpnt->request.nr_sectors); #endif cmd[1] = (SCpnt->lun << 5) & 0xe0; if (rscsi_disks[dev].sector_size == 1024){ if(block & 1) panic("sd.c:Bad block number requested"); if(this_count & 1) panic("sd.c:Bad block number requested"); block = block >> 1; this_count = this_count >> 1; }; if (rscsi_disks[dev].sector_size == 256){ block = block << 1; this_count = this_count << 1; }; if (((this_count > 0xff) || (block > 0x1fffff)) && rscsi_disks[dev].ten) { if (this_count > 0xffff) this_count = 0xffff; cmd[0] += READ_10 - READ_6 ; cmd[2] = (unsigned char) (block >> 24) & 0xff; cmd[3] = (unsigned char) (block >> 16) & 0xff; cmd[4] = (unsigned char) (block >> 8) & 0xff; cmd[5] = (unsigned char) block & 0xff; cmd[6] = cmd[9] = 0; cmd[7] = (unsigned char) (this_count >> 8) & 0xff; cmd[8] = (unsigned char) this_count & 0xff; } else { if (this_count > 0xff) this_count = 0xff; cmd[1] |= (unsigned char) ((block >> 16) & 0x1f); cmd[2] = (unsigned char) ((block >> 8) & 0xff); cmd[3] = (unsigned char) block & 0xff; cmd[4] = (unsigned char) this_count; cmd[5] = 0; } /* * We shouldn't disconnect in the middle of a sector, so with a dumb * host adapter, it's safe to assume that we can at least transfer * this many bytes between each connect / disconnect. */ SCpnt->transfersize = rscsi_disks[dev].sector_size; SCpnt->underflow = this_count << 9; scsi_do_cmd (SCpnt, (void *) cmd, buff, this_count * rscsi_disks[dev].sector_size, rw_intr, (SCpnt->device->type == TYPE_DISK ? SD_TIMEOUT : SD_MOD_TIMEOUT), MAX_RETRIES); } static int check_scsidisk_media_change(dev_t full_dev){ int retval; int target; struct inode inode; int flag = 0; target = DEVICE_NR(MINOR(full_dev)); if (target >= sd_template.dev_max || !rscsi_disks[target].device) { printk("SCSI disk request error: invalid device.\n"); return 0; }; if(!rscsi_disks[target].device->removable) return 0; inode.i_rdev = full_dev; /* This is all we really need here */ retval = sd_ioctl(&inode, NULL, SCSI_IOCTL_TEST_UNIT_READY, 0); if(retval){ /* Unable to test, unit probably not ready. This usually means there is no disc in the drive. Mark as changed, and we will figure it out later once the drive is available again. */ rscsi_disks[target].device->changed = 1; return 1; /* This will force a flush, if called from check_disk_change */ }; retval = rscsi_disks[target].device->changed; if(!flag) rscsi_disks[target].device->changed = 0; return retval; } static void sd_init_done (Scsi_Cmnd * SCpnt) { struct request * req; req = &SCpnt->request; req->dev = 0xfffe; /* Busy, but indicate request done */ if (req->sem != NULL) { up(req->sem); } } static int sd_init_onedisk(int i) { unsigned char cmd[10]; unsigned char *buffer; char spintime; int the_result, retries; Scsi_Cmnd * SCpnt; /* We need to retry the READ_CAPACITY because a UNIT_ATTENTION is considered a fatal error, and many devices report such an error just after a scsi bus reset. */ SCpnt = allocate_device(NULL, rscsi_disks[i].device, 1); buffer = (unsigned char *) scsi_malloc(512); spintime = 0; /* Spin up drives, as required. Only do this at boot time */ if (current == task[0]){ do{ cmd[0] = TEST_UNIT_READY; cmd[1] = (rscsi_disks[i].device->lun << 5) & 0xe0; memset ((void *) &cmd[2], 0, 8); SCpnt->request.dev = 0xffff; /* Mark as really busy again */ SCpnt->cmd_len = 0; SCpnt->sense_buffer[0] = 0; SCpnt->sense_buffer[2] = 0; scsi_do_cmd (SCpnt, (void *) cmd, (void *) buffer, 512, sd_init_done, SD_TIMEOUT, MAX_RETRIES); while(SCpnt->request.dev != 0xfffe) barrier(); the_result = SCpnt->result; /* Look for non-removable devices that return NOT_READY. Issue command to spin up drive for these cases. */ if(the_result && !rscsi_disks[i].device->removable && SCpnt->sense_buffer[2] == NOT_READY) { int time1; if(!spintime){ printk( "sd%c: Spinning up disk...", 'a' + i ); cmd[0] = START_STOP; cmd[1] = (rscsi_disks[i].device->lun << 5) & 0xe0; cmd[1] |= 1; /* Return immediately */ memset ((void *) &cmd[2], 0, 8); cmd[4] = 1; /* Start spin cycle */ SCpnt->request.dev = 0xffff; /* Mark as really busy again */ SCpnt->cmd_len = 0; SCpnt->sense_buffer[0] = 0; SCpnt->sense_buffer[2] = 0; scsi_do_cmd (SCpnt, (void *) cmd, (void *) buffer, 512, sd_init_done, SD_TIMEOUT, MAX_RETRIES); while(SCpnt->request.dev != 0xfffe) barrier(); spintime = jiffies; }; time1 = jiffies; while(jiffies < time1 + HZ); /* Wait 1 second for next try */ printk( "." ); }; } while(the_result && spintime && spintime+5000 > jiffies); if (spintime) { if (the_result) printk( "not responding...\n" ); else printk( "ready\n" ); } }; /* current == task[0] */ retries = 3; do { cmd[0] = READ_CAPACITY; cmd[1] = (rscsi_disks[i].device->lun << 5) & 0xe0; memset ((void *) &cmd[2], 0, 8); memset ((void *) buffer, 0, 8); SCpnt->request.dev = 0xffff; /* Mark as really busy again */ SCpnt->cmd_len = 0; SCpnt->sense_buffer[0] = 0; SCpnt->sense_buffer[2] = 0; scsi_do_cmd (SCpnt, (void *) cmd, (void *) buffer, 8, sd_init_done, SD_TIMEOUT, MAX_RETRIES); if (current == task[0]) while(SCpnt->request.dev != 0xfffe) barrier(); else if (SCpnt->request.dev != 0xfffe){ struct semaphore sem = MUTEX_LOCKED; SCpnt->request.sem = &sem; down(&sem); /* Hmm.. Have to ask about this one.. */ while (SCpnt->request.dev != 0xfffe) schedule(); }; the_result = SCpnt->result; retries--; } while(the_result && retries); SCpnt->request.dev = -1; /* Mark as not busy */ wake_up(&SCpnt->device->device_wait); /* Wake up a process waiting for device*/ /* * The SCSI standard says "READ CAPACITY is necessary for self configuring software" * While not mandatory, support of READ CAPACITY is strongly encouraged. * We used to die if we couldn't successfully do a READ CAPACITY. * But, now we go on about our way. The side effects of this are * * 1. We can't know block size with certainty. I have said "512 bytes is it" * as this is most common. * * 2. Recovery from when some one attempts to read past the end of the raw device will * be slower. */ if (the_result) { printk ("sd%c : READ CAPACITY failed.\n" "sd%c : status = %x, message = %02x, host = %d, driver = %02x \n", 'a' + i, 'a' + i, status_byte(the_result), msg_byte(the_result), host_byte(the_result), driver_byte(the_result) ); if (driver_byte(the_result) & DRIVER_SENSE) printk("sd%c : extended sense code = %1x \n", 'a' + i, SCpnt->sense_buffer[2] & 0xf); else printk("sd%c : sense not available. \n", 'a' + i); printk("sd%c : block size assumed to be 512 bytes, disk size 1GB. \n", 'a' + i); rscsi_disks[i].capacity = 0x1fffff; rscsi_disks[i].sector_size = 512; /* Set dirty bit for removable devices if not ready - sometimes drives will not report this properly. */ if(rscsi_disks[i].device->removable && SCpnt->sense_buffer[2] == NOT_READY) rscsi_disks[i].device->changed = 1; } else { rscsi_disks[i].capacity = (buffer[0] << 24) | (buffer[1] << 16) | (buffer[2] << 8) | buffer[3]; rscsi_disks[i].sector_size = (buffer[4] << 24) | (buffer[5] << 16) | (buffer[6] << 8) | buffer[7]; if (rscsi_disks[i].sector_size != 512 && rscsi_disks[i].sector_size != 1024 && rscsi_disks[i].sector_size != 256) { printk ("sd%c : unsupported sector size %d.\n", 'a' + i, rscsi_disks[i].sector_size); if(rscsi_disks[i].device->removable){ rscsi_disks[i].capacity = 0; } else { printk ("scsi : deleting disk entry.\n"); rscsi_disks[i].device = NULL; sd_template.nr_dev--; return i; }; } { /* The msdos fs need to know the hardware sector size So I have created this table. See ll_rw_blk.c Jacques Gelinas (Jacques@solucorp.qc.ca) */ int m; int hard_sector = rscsi_disks[i].sector_size; /* There is 16 minor allocated for each devices */ for (m=i<<4; m<((i+1)<<4); m++){ sd_hardsizes[m] = hard_sector; } printk ("SCSI Hardware sector size is %d bytes on device sd%c\n" ,hard_sector,i+'a'); } if(rscsi_disks[i].sector_size == 1024) rscsi_disks[i].capacity <<= 1; /* Change this into 512 byte sectors */ if(rscsi_disks[i].sector_size == 256) rscsi_disks[i].capacity >>= 1; /* Change this into 512 byte sectors */ } rscsi_disks[i].ten = 1; rscsi_disks[i].remap = 1; scsi_free(buffer, 512); return i; } /* The sd_init() function looks at all SCSI drives present, determines their size, and reads partition table entries for them. */ static void sd_init() { int i; static int sd_registered = 0; if (sd_template.dev_noticed == 0) return; if(!sd_registered) { if (register_blkdev(MAJOR_NR,"sd",&sd_fops)) { printk("Unable to get major %d for SCSI disk\n",MAJOR_NR); return; } sd_registered++; } /* We do not support attaching loadable devices yet. */ if(rscsi_disks) return; sd_template.dev_max = sd_template.dev_noticed + SD_EXTRA_DEVS; rscsi_disks = (Scsi_Disk *) scsi_init_malloc(sd_template.dev_max * sizeof(Scsi_Disk), GFP_ATOMIC); memset(rscsi_disks, 0, sd_template.dev_max * sizeof(Scsi_Disk)); sd_sizes = (int *) scsi_init_malloc((sd_template.dev_max << 4) * sizeof(int), GFP_ATOMIC); memset(sd_sizes, 0, (sd_template.dev_max << 4) * sizeof(int)); sd_blocksizes = (int *) scsi_init_malloc((sd_template.dev_max << 4) * sizeof(int), GFP_ATOMIC); sd_hardsizes = (int *) scsi_init_malloc((sd_template.dev_max << 4) * sizeof(struct hd_struct), GFP_ATOMIC); for(i=0;i<(sd_template.dev_max << 4);i++){ sd_blocksizes[i] = 1024; sd_hardsizes[i] = 512; } blksize_size[MAJOR_NR] = sd_blocksizes; hardsect_size[MAJOR_NR] = sd_hardsizes; sd = (struct hd_struct *) scsi_init_malloc((sd_template.dev_max << 4) * sizeof(struct hd_struct), GFP_ATOMIC); sd_gendisk.max_nr = sd_template.dev_max; sd_gendisk.part = sd; sd_gendisk.sizes = sd_sizes; sd_gendisk.real_devices = (void *) rscsi_disks; } static void sd_finish() { int i; blk_dev[MAJOR_NR].request_fn = DEVICE_REQUEST; sd_gendisk.next = gendisk_head; gendisk_head = &sd_gendisk; for (i = 0; i < sd_template.dev_max; ++i) if (!rscsi_disks[i].capacity && rscsi_disks[i].device) { i = sd_init_onedisk(i); if (scsi_loadable_module_flag && !rscsi_disks[i].has_part_table) { sd_sizes[i << 4] = rscsi_disks[i].capacity; revalidate_scsidisk(i << 4, 0); } rscsi_disks[i].has_part_table = 1; } /* If our host adapter is capable of scatter-gather, then we increase the read-ahead to 16 blocks (32 sectors). If not, we use a two block (4 sector) read ahead. */ if(rscsi_disks[0].device && rscsi_disks[0].device->host->sg_tablesize) read_ahead[MAJOR_NR] = 120; /* 64 sector read-ahead */ else read_ahead[MAJOR_NR] = 4; /* 4 sector read-ahead */ return; } static int sd_detect(Scsi_Device * SDp){ if(SDp->type != TYPE_DISK && SDp->type != TYPE_MOD) return 0; printk("Detected scsi disk sd%c at scsi%d, id %d, lun %d\n", 'a'+ (sd_template.dev_noticed++), SDp->host->host_no , SDp->id, SDp->lun); return 1; } static int sd_attach(Scsi_Device * SDp){ Scsi_Disk * dpnt; int i; if(SDp->type != TYPE_DISK && SDp->type != TYPE_MOD) return 0; if(sd_template.nr_dev >= sd_template.dev_max) { SDp->attached--; return 1; } for(dpnt = rscsi_disks, i=0; idevice) break; if(i >= sd_template.dev_max) panic ("scsi_devices corrupt (sd)"); SDp->scsi_request_fn = do_sd_request; rscsi_disks[i].device = SDp; rscsi_disks[i].has_part_table = 0; sd_template.nr_dev++; sd_gendisk.nr_real++; return 0; } #define DEVICE_BUSY rscsi_disks[target].device->busy #define USAGE rscsi_disks[target].device->access_count #define CAPACITY rscsi_disks[target].capacity #define MAYBE_REINIT sd_init_onedisk(target) #define GENDISK_STRUCT sd_gendisk /* 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. */ int revalidate_scsidisk(int dev, int maxusage){ int target, major; struct gendisk * gdev; unsigned long flags; int max_p; int start; int i; target = DEVICE_NR(MINOR(dev)); gdev = &GENDISK_STRUCT; save_flags(flags); cli(); if (DEVICE_BUSY || USAGE > maxusage) { restore_flags(flags); printk("Device busy for revalidation (usage=%d)\n", USAGE); return -EBUSY; }; DEVICE_BUSY = 1; restore_flags(flags); max_p = gdev->max_p; start = target << gdev->minor_shift; major = MAJOR_NR << 8; for (i=max_p - 1; i >=0 ; i--) { sync_dev(major | start | i); invalidate_inodes(major | start | i); invalidate_buffers(major | start | i); gdev->part[start+i].start_sect = 0; gdev->part[start+i].nr_sects = 0; }; #ifdef MAYBE_REINIT MAYBE_REINIT; #endif gdev->part[start].nr_sects = CAPACITY; resetup_one_dev(gdev, target); DEVICE_BUSY = 0; return 0; } static int fop_revalidate_scsidisk(dev_t dev){ return revalidate_scsidisk(dev, 0); } static void sd_detach(Scsi_Device * SDp) { Scsi_Disk * dpnt; int i; int max_p; int major; int start; for(dpnt = rscsi_disks, i=0; idevice == SDp) { /* If we are disconnecting a disk driver, sync and invalidate everything */ max_p = sd_gendisk.max_p; start = i << sd_gendisk.minor_shift; major = MAJOR_NR << 8; for (i=max_p - 1; i >=0 ; i--) { sync_dev(major | start | i); invalidate_inodes(major | start | i); invalidate_buffers(major | start | i); sd_gendisk.part[start+i].start_sect = 0; sd_gendisk.part[start+i].nr_sects = 0; sd_sizes[start+i] = 0; }; dpnt->has_part_table = 0; dpnt->device = NULL; dpnt->capacity = 0; SDp->attached--; sd_template.dev_noticed--; sd_template.nr_dev--; sd_gendisk.nr_real--; return; } return; } /* * Overrides for Emacs so that we follow Linus's tabbing style. * Emacs will notice this stuff at the end of the file and automatically * adjust the settings for this buffer only. This must remain at the end * of the file. * --------------------------------------------------------------------------- * Local variables: * c-indent-level: 8 * c-brace-imaginary-offset: 0 * c-brace-offset: -8 * c-argdecl-indent: 8 * c-label-offset: -8 * c-continued-statement-offset: 8 * c-continued-brace-offset: 0 * End: */