diff options
Diffstat (limited to 'drivers/scsi/atari_NCR5380.c')
-rw-r--r-- | drivers/scsi/atari_NCR5380.c | 2986 |
1 files changed, 2986 insertions, 0 deletions
diff --git a/drivers/scsi/atari_NCR5380.c b/drivers/scsi/atari_NCR5380.c new file mode 100644 index 000000000000..5d1e78ebed83 --- /dev/null +++ b/drivers/scsi/atari_NCR5380.c @@ -0,0 +1,2986 @@ +/* + * NCR 5380 generic driver routines. These should make it *trivial* + * to implement 5380 SCSI drivers under Linux with a non-trantor + * architecture. + * + * Note that these routines also work with NR53c400 family chips. + * + * Copyright 1993, Drew Eckhardt + * Visionary Computing + * (Unix and Linux consulting and custom programming) + * drew@colorado.edu + * +1 (303) 666-5836 + * + * DISTRIBUTION RELEASE 6. + * + * For more information, please consult + * + * NCR 5380 Family + * SCSI Protocol Controller + * Databook + * + * NCR Microelectronics + * 1635 Aeroplaza Drive + * Colorado Springs, CO 80916 + * 1+ (719) 578-3400 + * 1+ (800) 334-5454 + */ + +/* + * ++roman: To port the 5380 driver to the Atari, I had to do some changes in + * this file, too: + * + * - Some of the debug statements were incorrect (undefined variables and the + * like). I fixed that. + * + * - In information_transfer(), I think a #ifdef was wrong. Looking at the + * possible DMA transfer size should also happen for REAL_DMA. I added this + * in the #if statement. + * + * - When using real DMA, information_transfer() should return in a DATAOUT + * phase after starting the DMA. It has nothing more to do. + * + * - The interrupt service routine should run main after end of DMA, too (not + * only after RESELECTION interrupts). Additionally, it should _not_ test + * for more interrupts after running main, since a DMA process may have + * been started and interrupts are turned on now. The new int could happen + * inside the execution of NCR5380_intr(), leading to recursive + * calls. + * + * - I've added a function merge_contiguous_buffers() that tries to + * merge scatter-gather buffers that are located at contiguous + * physical addresses and can be processed with the same DMA setup. + * Since most scatter-gather operations work on a page (4K) of + * 4 buffers (1K), in more than 90% of all cases three interrupts and + * DMA setup actions are saved. + * + * - I've deleted all the stuff for AUTOPROBE_IRQ, REAL_DMA_POLL, PSEUDO_DMA + * and USLEEP, because these were messing up readability and will never be + * needed for Atari SCSI. + * + * - I've revised the NCR5380_main() calling scheme (relax the 'main_running' + * stuff), and 'main' is executed in a bottom half if awoken by an + * interrupt. + * + * - The code was quite cluttered up by "#if (NDEBUG & NDEBUG_*) printk..." + * constructs. In my eyes, this made the source rather unreadable, so I + * finally replaced that by the *_PRINTK() macros. + * + */ + +/* + * Further development / testing that should be done : + * 1. Test linked command handling code after Eric is ready with + * the high level code. + */ + +#if (NDEBUG & NDEBUG_LISTS) +#define LIST(x,y) \ + { printk("LINE:%d Adding %p to %p\n", __LINE__, (void*)(x), (void*)(y)); \ + if ((x)==(y)) udelay(5); } +#define REMOVE(w,x,y,z) \ + { printk("LINE:%d Removing: %p->%p %p->%p \n", __LINE__, \ + (void*)(w), (void*)(x), (void*)(y), (void*)(z)); \ + if ((x)==(y)) udelay(5); } +#else +#define LIST(x,y) +#define REMOVE(w,x,y,z) +#endif + +#ifndef notyet +#undef LINKED +#endif + +/* + * Design + * Issues : + * + * The other Linux SCSI drivers were written when Linux was Intel PC-only, + * and specifically for each board rather than each chip. This makes their + * adaptation to platforms like the Mac (Some of which use NCR5380's) + * more difficult than it has to be. + * + * Also, many of the SCSI drivers were written before the command queuing + * routines were implemented, meaning their implementations of queued + * commands were hacked on rather than designed in from the start. + * + * When I designed the Linux SCSI drivers I figured that + * while having two different SCSI boards in a system might be useful + * for debugging things, two of the same type wouldn't be used. + * Well, I was wrong and a number of users have mailed me about running + * multiple high-performance SCSI boards in a server. + * + * Finally, when I get questions from users, I have no idea what + * revision of my driver they are running. + * + * This driver attempts to address these problems : + * This is a generic 5380 driver. To use it on a different platform, + * one simply writes appropriate system specific macros (ie, data + * transfer - some PC's will use the I/O bus, 68K's must use + * memory mapped) and drops this file in their 'C' wrapper. + * + * As far as command queueing, two queues are maintained for + * each 5380 in the system - commands that haven't been issued yet, + * and commands that are currently executing. This means that an + * unlimited number of commands may be queued, letting + * more commands propagate from the higher driver levels giving higher + * throughput. Note that both I_T_L and I_T_L_Q nexuses are supported, + * allowing multiple commands to propagate all the way to a SCSI-II device + * while a command is already executing. + * + * To solve the multiple-boards-in-the-same-system problem, + * there is a separate instance structure for each instance + * of a 5380 in the system. So, multiple NCR5380 drivers will + * be able to coexist with appropriate changes to the high level + * SCSI code. + * + * A NCR5380_PUBLIC_REVISION macro is provided, with the release + * number (updated for each public release) printed by the + * NCR5380_print_options command, which should be called from the + * wrapper detect function, so that I know what release of the driver + * users are using. + * + * Issues specific to the NCR5380 : + * + * When used in a PIO or pseudo-dma mode, the NCR5380 is a braindead + * piece of hardware that requires you to sit in a loop polling for + * the REQ signal as long as you are connected. Some devices are + * brain dead (ie, many TEXEL CD ROM drives) and won't disconnect + * while doing long seek operations. + * + * The workaround for this is to keep track of devices that have + * disconnected. If the device hasn't disconnected, for commands that + * should disconnect, we do something like + * + * while (!REQ is asserted) { sleep for N usecs; poll for M usecs } + * + * Some tweaking of N and M needs to be done. An algorithm based + * on "time to data" would give the best results as long as short time + * to datas (ie, on the same track) were considered, however these + * broken devices are the exception rather than the rule and I'd rather + * spend my time optimizing for the normal case. + * + * Architecture : + * + * At the heart of the design is a coroutine, NCR5380_main, + * which is started when not running by the interrupt handler, + * timer, and queue command function. It attempts to establish + * I_T_L or I_T_L_Q nexuses by removing the commands from the + * issue queue and calling NCR5380_select() if a nexus + * is not established. + * + * Once a nexus is established, the NCR5380_information_transfer() + * phase goes through the various phases as instructed by the target. + * if the target goes into MSG IN and sends a DISCONNECT message, + * the command structure is placed into the per instance disconnected + * queue, and NCR5380_main tries to find more work. If USLEEP + * was defined, and the target is idle for too long, the system + * will try to sleep. + * + * If a command has disconnected, eventually an interrupt will trigger, + * calling NCR5380_intr() which will in turn call NCR5380_reselect + * to reestablish a nexus. This will run main if necessary. + * + * On command termination, the done function will be called as + * appropriate. + * + * SCSI pointers are maintained in the SCp field of SCSI command + * structures, being initialized after the command is connected + * in NCR5380_select, and set as appropriate in NCR5380_information_transfer. + * Note that in violation of the standard, an implicit SAVE POINTERS operation + * is done, since some BROKEN disks fail to issue an explicit SAVE POINTERS. + */ + +/* + * Using this file : + * This file a skeleton Linux SCSI driver for the NCR 5380 series + * of chips. To use it, you write an architecture specific functions + * and macros and include this file in your driver. + * + * These macros control options : + * AUTOSENSE - if defined, REQUEST SENSE will be performed automatically + * for commands that return with a CHECK CONDITION status. + * + * LINKED - if defined, linked commands are supported. + * + * REAL_DMA - if defined, REAL DMA is used during the data transfer phases. + * + * SUPPORT_TAGS - if defined, SCSI-2 tagged queuing is used where possible + * + * These macros MUST be defined : + * + * NCR5380_read(register) - read from the specified register + * + * NCR5380_write(register, value) - write to the specific register + * + * Either real DMA *or* pseudo DMA may be implemented + * REAL functions : + * NCR5380_REAL_DMA should be defined if real DMA is to be used. + * Note that the DMA setup functions should return the number of bytes + * that they were able to program the controller for. + * + * Also note that generic i386/PC versions of these macros are + * available as NCR5380_i386_dma_write_setup, + * NCR5380_i386_dma_read_setup, and NCR5380_i386_dma_residual. + * + * NCR5380_dma_write_setup(instance, src, count) - initialize + * NCR5380_dma_read_setup(instance, dst, count) - initialize + * NCR5380_dma_residual(instance); - residual count + * + * PSEUDO functions : + * NCR5380_pwrite(instance, src, count) + * NCR5380_pread(instance, dst, count); + * + * If nothing specific to this implementation needs doing (ie, with external + * hardware), you must also define + * + * NCR5380_queue_command + * NCR5380_reset + * NCR5380_abort + * NCR5380_proc_info + * + * to be the global entry points into the specific driver, ie + * #define NCR5380_queue_command t128_queue_command. + * + * If this is not done, the routines will be defined as static functions + * with the NCR5380* names and the user must provide a globally + * accessible wrapper function. + * + * The generic driver is initialized by calling NCR5380_init(instance), + * after setting the appropriate host specific fields and ID. If the + * driver wishes to autoprobe for an IRQ line, the NCR5380_probe_irq(instance, + * possible) function may be used. Before the specific driver initialization + * code finishes, NCR5380_print_options should be called. + */ + +static struct Scsi_Host *first_instance = NULL; +static Scsi_Host_Template *the_template = NULL; + +/* Macros ease life... :-) */ +#define SETUP_HOSTDATA(in) \ + struct NCR5380_hostdata *hostdata = \ + (struct NCR5380_hostdata *)(in)->hostdata +#define HOSTDATA(in) ((struct NCR5380_hostdata *)(in)->hostdata) + +#define NEXT(cmd) ((Scsi_Cmnd *)((cmd)->host_scribble)) +#define NEXTADDR(cmd) ((Scsi_Cmnd **)&((cmd)->host_scribble)) + +#define HOSTNO instance->host_no +#define H_NO(cmd) (cmd)->device->host->host_no + +#ifdef SUPPORT_TAGS + +/* + * Functions for handling tagged queuing + * ===================================== + * + * ++roman (01/96): Now I've implemented SCSI-2 tagged queuing. Some notes: + * + * Using consecutive numbers for the tags is no good idea in my eyes. There + * could be wrong re-usings if the counter (8 bit!) wraps and some early + * command has been preempted for a long time. My solution: a bitfield for + * remembering used tags. + * + * There's also the problem that each target has a certain queue size, but we + * cannot know it in advance :-( We just see a QUEUE_FULL status being + * returned. So, in this case, the driver internal queue size assumption is + * reduced to the number of active tags if QUEUE_FULL is returned by the + * target. The command is returned to the mid-level, but with status changed + * to BUSY, since --as I've seen-- the mid-level can't handle QUEUE_FULL + * correctly. + * + * We're also not allowed running tagged commands as long as an untagged + * command is active. And REQUEST SENSE commands after a contingent allegiance + * condition _must_ be untagged. To keep track whether an untagged command has + * been issued, the host->busy array is still employed, as it is without + * support for tagged queuing. + * + * One could suspect that there are possible race conditions between + * is_lun_busy(), cmd_get_tag() and cmd_free_tag(). But I think this isn't the + * case: is_lun_busy() and cmd_get_tag() are both called from NCR5380_main(), + * which already guaranteed to be running at most once. It is also the only + * place where tags/LUNs are allocated. So no other allocation can slip + * between that pair, there could only happen a reselection, which can free a + * tag, but that doesn't hurt. Only the sequence in cmd_free_tag() becomes + * important: the tag bit must be cleared before 'nr_allocated' is decreased. + */ + +/* -1 for TAG_NONE is not possible with unsigned char cmd->tag */ +#undef TAG_NONE +#define TAG_NONE 0xff + +typedef struct { + DECLARE_BITMAP(allocated, MAX_TAGS); + int nr_allocated; + int queue_size; +} TAG_ALLOC; + +static TAG_ALLOC TagAlloc[8][8]; /* 8 targets and 8 LUNs */ + + +static void __init init_tags( void ) +{ + int target, lun; + TAG_ALLOC *ta; + + if (!setup_use_tagged_queuing) + return; + + for( target = 0; target < 8; ++target ) { + for( lun = 0; lun < 8; ++lun ) { + ta = &TagAlloc[target][lun]; + bitmap_zero(ta->allocated, MAX_TAGS); + ta->nr_allocated = 0; + /* At the beginning, assume the maximum queue size we could + * support (MAX_TAGS). This value will be decreased if the target + * returns QUEUE_FULL status. + */ + ta->queue_size = MAX_TAGS; + } + } +} + + +/* Check if we can issue a command to this LUN: First see if the LUN is marked + * busy by an untagged command. If the command should use tagged queuing, also + * check that there is a free tag and the target's queue won't overflow. This + * function should be called with interrupts disabled to avoid race + * conditions. + */ + +static int is_lun_busy( Scsi_Cmnd *cmd, int should_be_tagged ) +{ + SETUP_HOSTDATA(cmd->device->host); + + if (hostdata->busy[cmd->device->id] & (1 << cmd->device->lun)) + return( 1 ); + if (!should_be_tagged || + !setup_use_tagged_queuing || !cmd->device->tagged_supported) + return( 0 ); + if (TagAlloc[cmd->device->id][cmd->device->lun].nr_allocated >= + TagAlloc[cmd->device->id][cmd->device->lun].queue_size ) { + TAG_PRINTK( "scsi%d: target %d lun %d: no free tags\n", + H_NO(cmd), cmd->device->id, cmd->device->lun ); + return( 1 ); + } + return( 0 ); +} + + +/* Allocate a tag for a command (there are no checks anymore, check_lun_busy() + * must be called before!), or reserve the LUN in 'busy' if the command is + * untagged. + */ + +static void cmd_get_tag( Scsi_Cmnd *cmd, int should_be_tagged ) +{ + SETUP_HOSTDATA(cmd->device->host); + + /* If we or the target don't support tagged queuing, allocate the LUN for + * an untagged command. + */ + if (!should_be_tagged || + !setup_use_tagged_queuing || !cmd->device->tagged_supported) { + cmd->tag = TAG_NONE; + hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun); + TAG_PRINTK( "scsi%d: target %d lun %d now allocated by untagged " + "command\n", H_NO(cmd), cmd->device->id, cmd->device->lun ); + } + else { + TAG_ALLOC *ta = &TagAlloc[cmd->device->id][cmd->device->lun]; + + cmd->tag = find_first_zero_bit( ta->allocated, MAX_TAGS ); + set_bit( cmd->tag, ta->allocated ); + ta->nr_allocated++; + TAG_PRINTK( "scsi%d: using tag %d for target %d lun %d " + "(now %d tags in use)\n", + H_NO(cmd), cmd->tag, cmd->device->id, cmd->device->lun, + ta->nr_allocated ); + } +} + + +/* Mark the tag of command 'cmd' as free, or in case of an untagged command, + * unlock the LUN. + */ + +static void cmd_free_tag( Scsi_Cmnd *cmd ) +{ + SETUP_HOSTDATA(cmd->device->host); + + if (cmd->tag == TAG_NONE) { + hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun); + TAG_PRINTK( "scsi%d: target %d lun %d untagged cmd finished\n", + H_NO(cmd), cmd->device->id, cmd->device->lun ); + } + else if (cmd->tag >= MAX_TAGS) { + printk(KERN_NOTICE "scsi%d: trying to free bad tag %d!\n", + H_NO(cmd), cmd->tag ); + } + else { + TAG_ALLOC *ta = &TagAlloc[cmd->device->id][cmd->device->lun]; + clear_bit( cmd->tag, ta->allocated ); + ta->nr_allocated--; + TAG_PRINTK( "scsi%d: freed tag %d for target %d lun %d\n", + H_NO(cmd), cmd->tag, cmd->device->id, cmd->device->lun ); + } +} + + +static void free_all_tags( void ) +{ + int target, lun; + TAG_ALLOC *ta; + + if (!setup_use_tagged_queuing) + return; + + for( target = 0; target < 8; ++target ) { + for( lun = 0; lun < 8; ++lun ) { + ta = &TagAlloc[target][lun]; + bitmap_zero(ta->allocated, MAX_TAGS); + ta->nr_allocated = 0; + } + } +} + +#endif /* SUPPORT_TAGS */ + + +/* + * Function: void merge_contiguous_buffers( Scsi_Cmnd *cmd ) + * + * Purpose: Try to merge several scatter-gather requests into one DMA + * transfer. This is possible if the scatter buffers lie on + * physical contiguous addresses. + * + * Parameters: Scsi_Cmnd *cmd + * The command to work on. The first scatter buffer's data are + * assumed to be already transfered into ptr/this_residual. + */ + +static void merge_contiguous_buffers( Scsi_Cmnd *cmd ) +{ + unsigned long endaddr; +#if (NDEBUG & NDEBUG_MERGING) + unsigned long oldlen = cmd->SCp.this_residual; + int cnt = 1; +#endif + + for (endaddr = virt_to_phys(cmd->SCp.ptr + cmd->SCp.this_residual - 1) + 1; + cmd->SCp.buffers_residual && + virt_to_phys(page_address(cmd->SCp.buffer[1].page)+ + cmd->SCp.buffer[1].offset) == endaddr; ) { + MER_PRINTK("VTOP(%p) == %08lx -> merging\n", + cmd->SCp.buffer[1].address, endaddr); +#if (NDEBUG & NDEBUG_MERGING) + ++cnt; +#endif + ++cmd->SCp.buffer; + --cmd->SCp.buffers_residual; + cmd->SCp.this_residual += cmd->SCp.buffer->length; + endaddr += cmd->SCp.buffer->length; + } +#if (NDEBUG & NDEBUG_MERGING) + if (oldlen != cmd->SCp.this_residual) + MER_PRINTK("merged %d buffers from %p, new length %08x\n", + cnt, cmd->SCp.ptr, cmd->SCp.this_residual); +#endif +} + +/* + * Function : void initialize_SCp(Scsi_Cmnd *cmd) + * + * Purpose : initialize the saved data pointers for cmd to point to the + * start of the buffer. + * + * Inputs : cmd - Scsi_Cmnd structure to have pointers reset. + */ + +static __inline__ void initialize_SCp(Scsi_Cmnd *cmd) +{ + /* + * Initialize the Scsi Pointer field so that all of the commands in the + * various queues are valid. + */ + + if (cmd->use_sg) { + cmd->SCp.buffer = (struct scatterlist *) cmd->buffer; + cmd->SCp.buffers_residual = cmd->use_sg - 1; + cmd->SCp.ptr = (char *)page_address(cmd->SCp.buffer->page)+ + cmd->SCp.buffer->offset; + cmd->SCp.this_residual = cmd->SCp.buffer->length; + /* ++roman: Try to merge some scatter-buffers if they are at + * contiguous physical addresses. + */ + merge_contiguous_buffers( cmd ); + } else { + cmd->SCp.buffer = NULL; + cmd->SCp.buffers_residual = 0; + cmd->SCp.ptr = (char *) cmd->request_buffer; + cmd->SCp.this_residual = cmd->request_bufflen; + } +} + +#include <linux/config.h> +#include <linux/delay.h> + +#if NDEBUG +static struct { + unsigned char mask; + const char * name;} +signals[] = {{ SR_DBP, "PARITY"}, { SR_RST, "RST" }, { SR_BSY, "BSY" }, + { SR_REQ, "REQ" }, { SR_MSG, "MSG" }, { SR_CD, "CD" }, { SR_IO, "IO" }, + { SR_SEL, "SEL" }, {0, NULL}}, +basrs[] = {{BASR_ATN, "ATN"}, {BASR_ACK, "ACK"}, {0, NULL}}, +icrs[] = {{ICR_ASSERT_RST, "ASSERT RST"},{ICR_ASSERT_ACK, "ASSERT ACK"}, + {ICR_ASSERT_BSY, "ASSERT BSY"}, {ICR_ASSERT_SEL, "ASSERT SEL"}, + {ICR_ASSERT_ATN, "ASSERT ATN"}, {ICR_ASSERT_DATA, "ASSERT DATA"}, + {0, NULL}}, +mrs[] = {{MR_BLOCK_DMA_MODE, "MODE BLOCK DMA"}, {MR_TARGET, "MODE TARGET"}, + {MR_ENABLE_PAR_CHECK, "MODE PARITY CHECK"}, {MR_ENABLE_PAR_INTR, + "MODE PARITY INTR"}, {MR_ENABLE_EOP_INTR,"MODE EOP INTR"}, + {MR_MONITOR_BSY, "MODE MONITOR BSY"}, + {MR_DMA_MODE, "MODE DMA"}, {MR_ARBITRATE, "MODE ARBITRATION"}, + {0, NULL}}; + +/* + * Function : void NCR5380_print(struct Scsi_Host *instance) + * + * Purpose : print the SCSI bus signals for debugging purposes + * + * Input : instance - which NCR5380 + */ + +static void NCR5380_print(struct Scsi_Host *instance) { + unsigned char status, data, basr, mr, icr, i; + unsigned long flags; + + local_irq_save(flags); + data = NCR5380_read(CURRENT_SCSI_DATA_REG); + status = NCR5380_read(STATUS_REG); + mr = NCR5380_read(MODE_REG); + icr = NCR5380_read(INITIATOR_COMMAND_REG); + basr = NCR5380_read(BUS_AND_STATUS_REG); + local_irq_restore(flags); + printk("STATUS_REG: %02x ", status); + for (i = 0; signals[i].mask ; ++i) + if (status & signals[i].mask) + printk(",%s", signals[i].name); + printk("\nBASR: %02x ", basr); + for (i = 0; basrs[i].mask ; ++i) + if (basr & basrs[i].mask) + printk(",%s", basrs[i].name); + printk("\nICR: %02x ", icr); + for (i = 0; icrs[i].mask; ++i) + if (icr & icrs[i].mask) + printk(",%s", icrs[i].name); + printk("\nMODE: %02x ", mr); + for (i = 0; mrs[i].mask; ++i) + if (mr & mrs[i].mask) + printk(",%s", mrs[i].name); + printk("\n"); +} + +static struct { + unsigned char value; + const char *name; +} phases[] = { + {PHASE_DATAOUT, "DATAOUT"}, {PHASE_DATAIN, "DATAIN"}, {PHASE_CMDOUT, "CMDOUT"}, + {PHASE_STATIN, "STATIN"}, {PHASE_MSGOUT, "MSGOUT"}, {PHASE_MSGIN, "MSGIN"}, + {PHASE_UNKNOWN, "UNKNOWN"}}; + +/* + * Function : void NCR5380_print_phase(struct Scsi_Host *instance) + * + * Purpose : print the current SCSI phase for debugging purposes + * + * Input : instance - which NCR5380 + */ + +static void NCR5380_print_phase(struct Scsi_Host *instance) +{ + unsigned char status; + int i; + + status = NCR5380_read(STATUS_REG); + if (!(status & SR_REQ)) + printk(KERN_DEBUG "scsi%d: REQ not asserted, phase unknown.\n", HOSTNO); + else { + for (i = 0; (phases[i].value != PHASE_UNKNOWN) && + (phases[i].value != (status & PHASE_MASK)); ++i); + printk(KERN_DEBUG "scsi%d: phase %s\n", HOSTNO, phases[i].name); + } +} + +#else /* !NDEBUG */ + +/* dummies... */ +__inline__ void NCR5380_print(struct Scsi_Host *instance) { }; +__inline__ void NCR5380_print_phase(struct Scsi_Host *instance) { }; + +#endif + +/* + * ++roman: New scheme of calling NCR5380_main() + * + * If we're not in an interrupt, we can call our main directly, it cannot be + * already running. Else, we queue it on a task queue, if not 'main_running' + * tells us that a lower level is already executing it. This way, + * 'main_running' needs not be protected in a special way. + * + * queue_main() is a utility function for putting our main onto the task + * queue, if main_running is false. It should be called only from a + * interrupt or bottom half. + */ + +#include <linux/workqueue.h> +#include <linux/interrupt.h> + +static volatile int main_running = 0; +static DECLARE_WORK(NCR5380_tqueue, (void (*)(void*))NCR5380_main, NULL); + +static __inline__ void queue_main(void) +{ + if (!main_running) { + /* If in interrupt and NCR5380_main() not already running, + queue it on the 'immediate' task queue, to be processed + immediately after the current interrupt processing has + finished. */ + schedule_work(&NCR5380_tqueue); + } + /* else: nothing to do: the running NCR5380_main() will pick up + any newly queued command. */ +} + + +static inline void NCR5380_all_init (void) +{ + static int done = 0; + if (!done) { + INI_PRINTK("scsi : NCR5380_all_init()\n"); + done = 1; + } +} + + +/* + * Function : void NCR58380_print_options (struct Scsi_Host *instance) + * + * Purpose : called by probe code indicating the NCR5380 driver + * options that were selected. + * + * Inputs : instance, pointer to this instance. Unused. + */ + +static void __init NCR5380_print_options (struct Scsi_Host *instance) +{ + printk(" generic options" +#ifdef AUTOSENSE + " AUTOSENSE" +#endif +#ifdef REAL_DMA + " REAL DMA" +#endif +#ifdef PARITY + " PARITY" +#endif +#ifdef SUPPORT_TAGS + " SCSI-2 TAGGED QUEUING" +#endif + ); + printk(" generic release=%d", NCR5380_PUBLIC_RELEASE); +} + +/* + * Function : void NCR5380_print_status (struct Scsi_Host *instance) + * + * Purpose : print commands in the various queues, called from + * NCR5380_abort and NCR5380_debug to aid debugging. + * + * Inputs : instance, pointer to this instance. + */ + +static void NCR5380_print_status (struct Scsi_Host *instance) +{ + char *pr_bfr; + char *start; + int len; + + NCR_PRINT(NDEBUG_ANY); + NCR_PRINT_PHASE(NDEBUG_ANY); + + pr_bfr = (char *) __get_free_page(GFP_ATOMIC); + if (!pr_bfr) { + printk("NCR5380_print_status: no memory for print buffer\n"); + return; + } + len = NCR5380_proc_info(pr_bfr, &start, 0, PAGE_SIZE, HOSTNO, 0); + pr_bfr[len] = 0; + printk("\n%s\n", pr_bfr); + free_page((unsigned long) pr_bfr); +} + + +/******************************************/ +/* + * /proc/scsi/[dtc pas16 t128 generic]/[0-ASC_NUM_BOARD_SUPPORTED] + * + * *buffer: I/O buffer + * **start: if inout == FALSE pointer into buffer where user read should start + * offset: current offset + * length: length of buffer + * hostno: Scsi_Host host_no + * inout: TRUE - user is writing; FALSE - user is reading + * + * Return the number of bytes read from or written +*/ + +#undef SPRINTF +#define SPRINTF(fmt,args...) \ + do { if (pos + strlen(fmt) + 20 /* slop */ < buffer + length) \ + pos += sprintf(pos, fmt , ## args); } while(0) +static +char *lprint_Scsi_Cmnd (Scsi_Cmnd *cmd, char *pos, char *buffer, int length); + +static +int NCR5380_proc_info (struct Scsi_Host *instance, char *buffer, char **start, off_t offset, + int length, int inout) +{ + char *pos = buffer; + struct NCR5380_hostdata *hostdata; + Scsi_Cmnd *ptr; + unsigned long flags; + off_t begin = 0; +#define check_offset() \ + do { \ + if (pos - buffer < offset - begin) { \ + begin += pos - buffer; \ + pos = buffer; \ + } \ + } while (0) + + hostdata = (struct NCR5380_hostdata *)instance->hostdata; + + if (inout) { /* Has data been written to the file ? */ + return(-ENOSYS); /* Currently this is a no-op */ + } + SPRINTF("NCR5380 core release=%d.\n", NCR5380_PUBLIC_RELEASE); + check_offset(); + local_irq_save(flags); + SPRINTF("NCR5380: coroutine is%s running.\n", main_running ? "" : "n't"); + check_offset(); + if (!hostdata->connected) + SPRINTF("scsi%d: no currently connected command\n", HOSTNO); + else + pos = lprint_Scsi_Cmnd ((Scsi_Cmnd *) hostdata->connected, + pos, buffer, length); + SPRINTF("scsi%d: issue_queue\n", HOSTNO); + check_offset(); + for (ptr = (Scsi_Cmnd *) hostdata->issue_queue; ptr; ptr = NEXT(ptr)) { + pos = lprint_Scsi_Cmnd (ptr, pos, buffer, length); + check_offset(); + } + + SPRINTF("scsi%d: disconnected_queue\n", HOSTNO); + check_offset(); + for (ptr = (Scsi_Cmnd *) hostdata->disconnected_queue; ptr; + ptr = NEXT(ptr)) { + pos = lprint_Scsi_Cmnd (ptr, pos, buffer, length); + check_offset(); + } + + local_irq_restore(flags); + *start = buffer + (offset - begin); + if (pos - buffer < offset - begin) + return 0; + else if (pos - buffer - (offset - begin) < length) + return pos - buffer - (offset - begin); + return length; +} + +static char * +lprint_Scsi_Cmnd (Scsi_Cmnd *cmd, char *pos, char *buffer, int length) +{ + int i, s; + unsigned char *command; + SPRINTF("scsi%d: destination target %d, lun %d\n", + H_NO(cmd), cmd->device->id, cmd->device->lun); + SPRINTF(" command = "); + command = cmd->cmnd; + SPRINTF("%2d (0x%02x)", command[0], command[0]); + for (i = 1, s = COMMAND_SIZE(command[0]); i < s; ++i) + SPRINTF(" %02x", command[i]); + SPRINTF("\n"); + return pos; +} + + +/* + * Function : void NCR5380_init (struct Scsi_Host *instance) + * + * Purpose : initializes *instance and corresponding 5380 chip. + * + * Inputs : instance - instantiation of the 5380 driver. + * + * Notes : I assume that the host, hostno, and id bits have been + * set correctly. I don't care about the irq and other fields. + * + */ + +static int NCR5380_init (struct Scsi_Host *instance, int flags) +{ + int i; + SETUP_HOSTDATA(instance); + + NCR5380_all_init(); + + hostdata->aborted = 0; + hostdata->id_mask = 1 << instance->this_id; + hostdata->id_higher_mask = 0; + for (i = hostdata->id_mask; i <= 0x80; i <<= 1) + if (i > hostdata->id_mask) + hostdata->id_higher_mask |= i; + for (i = 0; i < 8; ++i) + hostdata->busy[i] = 0; +#ifdef SUPPORT_TAGS + init_tags(); +#endif +#if defined (REAL_DMA) + hostdata->dma_len = 0; +#endif + hostdata->targets_present = 0; + hostdata->connected = NULL; + hostdata->issue_queue = NULL; + hostdata->disconnected_queue = NULL; + hostdata->flags = FLAG_CHECK_LAST_BYTE_SENT; + + if (!the_template) { + the_template = instance->hostt; + first_instance = instance; + } + + +#ifndef AUTOSENSE + if ((instance->cmd_per_lun > 1) || (instance->can_queue > 1)) + printk("scsi%d: WARNING : support for multiple outstanding commands enabled\n" + " without AUTOSENSE option, contingent allegiance conditions may\n" + " be incorrectly cleared.\n", HOSTNO); +#endif /* def AUTOSENSE */ + + NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); + NCR5380_write(MODE_REG, MR_BASE); + NCR5380_write(TARGET_COMMAND_REG, 0); + NCR5380_write(SELECT_ENABLE_REG, 0); + + return 0; +} + +/* + * Function : int NCR5380_queue_command (Scsi_Cmnd *cmd, + * void (*done)(Scsi_Cmnd *)) + * + * Purpose : enqueues a SCSI command + * + * Inputs : cmd - SCSI command, done - function called on completion, with + * a pointer to the command descriptor. + * + * Returns : 0 + * + * Side effects : + * cmd is added to the per instance issue_queue, with minor + * twiddling done to the host specific fields of cmd. If the + * main coroutine is not running, it is restarted. + * + */ + +static +int NCR5380_queue_command (Scsi_Cmnd *cmd, void (*done)(Scsi_Cmnd *)) +{ + SETUP_HOSTDATA(cmd->device->host); + Scsi_Cmnd *tmp; + int oldto; + unsigned long flags; + extern int update_timeout(Scsi_Cmnd * SCset, int timeout); + +#if (NDEBUG & NDEBUG_NO_WRITE) + switch (cmd->cmnd[0]) { + case WRITE_6: + case WRITE_10: + printk(KERN_NOTICE "scsi%d: WRITE attempted with NO_WRITE debugging flag set\n", + H_NO(cmd)); + cmd->result = (DID_ERROR << 16); + done(cmd); + return 0; + } +#endif /* (NDEBUG & NDEBUG_NO_WRITE) */ + + +#ifdef NCR5380_STATS +# if 0 + if (!hostdata->connected && !hostdata->issue_queue && + !hostdata->disconnected_queue) { + hostdata->timebase = jiffies; + } +# endif +# ifdef NCR5380_STAT_LIMIT + if (cmd->request_bufflen > NCR5380_STAT_LIMIT) +# endif + switch (cmd->cmnd[0]) + { + case WRITE: + case WRITE_6: + case WRITE_10: + hostdata->time_write[cmd->device->id] -= (jiffies - hostdata->timebase); + hostdata->bytes_write[cmd->device->id] += cmd->request_bufflen; + hostdata->pendingw++; + break; + case READ: + case READ_6: + case READ_10: + hostdata->time_read[cmd->device->id] -= (jiffies - hostdata->timebase); + hostdata->bytes_read[cmd->device->id] += cmd->request_bufflen; + hostdata->pendingr++; + break; + } +#endif + + /* + * We use the host_scribble field as a pointer to the next command + * in a queue + */ + + NEXT(cmd) = NULL; + cmd->scsi_done = done; + + cmd->result = 0; + + + /* + * Insert the cmd into the issue queue. Note that REQUEST SENSE + * commands are added to the head of the queue since any command will + * clear the contingent allegiance condition that exists and the + * sense data is only guaranteed to be valid while the condition exists. + */ + + local_irq_save(flags); + /* ++guenther: now that the issue queue is being set up, we can lock ST-DMA. + * Otherwise a running NCR5380_main may steal the lock. + * Lock before actually inserting due to fairness reasons explained in + * atari_scsi.c. If we insert first, then it's impossible for this driver + * to release the lock. + * Stop timer for this command while waiting for the lock, or timeouts + * may happen (and they really do), and it's no good if the command doesn't + * appear in any of the queues. + * ++roman: Just disabling the NCR interrupt isn't sufficient here, + * because also a timer int can trigger an abort or reset, which would + * alter queues and touch the lock. + */ + if (!IS_A_TT()) { + oldto = update_timeout(cmd, 0); + falcon_get_lock(); + update_timeout(cmd, oldto); + } + if (!(hostdata->issue_queue) || (cmd->cmnd[0] == REQUEST_SENSE)) { + LIST(cmd, hostdata->issue_queue); + NEXT(cmd) = hostdata->issue_queue; + hostdata->issue_queue = cmd; + } else { + for (tmp = (Scsi_Cmnd *)hostdata->issue_queue; + NEXT(tmp); tmp = NEXT(tmp)) + ; + LIST(cmd, tmp); + NEXT(tmp) = cmd; + } + local_irq_restore(flags); + + QU_PRINTK("scsi%d: command added to %s of queue\n", H_NO(cmd), + (cmd->cmnd[0] == REQUEST_SENSE) ? "head" : "tail"); + + /* If queue_command() is called from an interrupt (real one or bottom + * half), we let queue_main() do the job of taking care about main. If it + * is already running, this is a no-op, else main will be queued. + * + * If we're not in an interrupt, we can call NCR5380_main() + * unconditionally, because it cannot be already running. + */ + if (in_interrupt() || ((flags >> 8) & 7) >= 6) + queue_main(); + else + NCR5380_main(NULL); + return 0; +} + +/* + * Function : NCR5380_main (void) + * + * Purpose : NCR5380_main is a coroutine that runs as long as more work can + * be done on the NCR5380 host adapters in a system. Both + * NCR5380_queue_command() and NCR5380_intr() will try to start it + * in case it is not running. + * + * NOTE : NCR5380_main exits with interrupts *disabled*, the caller should + * reenable them. This prevents reentrancy and kernel stack overflow. + */ + +static void NCR5380_main (void *bl) +{ + Scsi_Cmnd *tmp, *prev; + struct Scsi_Host *instance = first_instance; + struct NCR5380_hostdata *hostdata = HOSTDATA(instance); + int done; + unsigned long flags; + + /* + * We run (with interrupts disabled) until we're sure that none of + * the host adapters have anything that can be done, at which point + * we set main_running to 0 and exit. + * + * Interrupts are enabled before doing various other internal + * instructions, after we've decided that we need to run through + * the loop again. + * + * this should prevent any race conditions. + * + * ++roman: Just disabling the NCR interrupt isn't sufficient here, + * because also a timer int can trigger an abort or reset, which can + * alter queues and touch the Falcon lock. + */ + + /* Tell int handlers main() is now already executing. Note that + no races are possible here. If an int comes in before + 'main_running' is set here, and queues/executes main via the + task queue, it doesn't do any harm, just this instance of main + won't find any work left to do. */ + if (main_running) + return; + main_running = 1; + + local_save_flags(flags); + |