diff options
| -rw-r--r-- | drivers/scsi/NCR5380.c | 170 | ||||
| -rw-r--r-- | drivers/scsi/atari_NCR5380.c | 109 |
2 files changed, 54 insertions, 225 deletions
diff --git a/drivers/scsi/NCR5380.c b/drivers/scsi/NCR5380.c index 38b03af..b968b30 100644 --- a/drivers/scsi/NCR5380.c +++ b/drivers/scsi/NCR5380.c @@ -25,45 +25,8 @@ */ /* - * Revision 1.10 1998/9/2 Alan Cox - * (alan@lxorguk.ukuu.org.uk) - * Fixed up the timer lockups reported so far. Things still suck. Looking - * forward to 2.3 and per device request queues. Then it'll be possible to - * SMP thread this beast and improve life no end. - - * Revision 1.9 1997/7/27 Ronald van Cuijlenborg - * (ronald.van.cuijlenborg@tip.nl or nutty@dds.nl) - * (hopefully) fixed and enhanced USLEEP - * added support for DTC3181E card (for Mustek scanner) - * - - * Revision 1.8 Ingmar Baumgart - * (ingmar@gonzo.schwaben.de) - * added support for NCR53C400a card - * - - * Revision 1.7 1996/3/2 Ray Van Tassle (rayvt@comm.mot.com) - * added proc_info - * added support needed for DTC 3180/3280 - * fixed a couple of bugs - * - - * Revision 1.5 1994/01/19 09:14:57 drew - * Fixed udelay() hack that was being used on DATAOUT phases - * instead of a proper wait for the final handshake. - * - * Revision 1.4 1994/01/19 06:44:25 drew - * *** empty log message *** - * - * Revision 1.3 1994/01/19 05:24:40 drew - * Added support for TCR LAST_BYTE_SENT bit. - * - * Revision 1.2 1994/01/15 06:14:11 drew - * REAL DMA support, bug fixes. - * - * Revision 1.1 1994/01/15 06:00:54 drew - * Initial revision - * + * With contributions from Ray Van Tassle, Ingmar Baumgart, + * Ronald van Cuijlenborg, Alan Cox and others. */ /* @@ -98,12 +61,6 @@ * transfer - some PC's will use the I/O bus, 68K's must use * memory mapped) and drops this file in their 'C' wrapper. * - * (Note from hch: unfortunately it was not enough for the different - * m68k folks and instead of improving this driver they copied it - * and hacked it up for their needs. As a consequence they lost - * most updates to this driver. Maybe someone will fix all these - * drivers to use a common core one day..) - * * 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 @@ -180,9 +137,6 @@ * rely on phase mismatch and EOP interrupts to determine end * of phase. * - * Defaults for these will be provided although the user may want to adjust - * these to allocate CPU resources to the SCSI driver or "real" code. - * * These macros MUST be defined : * * NCR5380_read(register) - read from the specified register @@ -219,7 +173,7 @@ static int do_abort(struct Scsi_Host *); static void do_reset(struct Scsi_Host *); -/* +/** * initialize_SCp - init the scsi pointer field * @cmd: command block to set up * @@ -368,8 +322,6 @@ mrs[] = { * @instance: adapter state to dump * * Print the SCSI bus signals for debugging purposes - * - * Locks: caller holds hostdata lock (not essential) */ static void NCR5380_print(struct Scsi_Host *instance) @@ -402,13 +354,11 @@ static void NCR5380_print(struct Scsi_Host *instance) } -/* +/** * NCR5380_print_phase - show SCSI phase * @instance: adapter to dump * * Print the current SCSI phase for debugging purposes - * - * Locks: none */ static void NCR5380_print_phase(struct Scsi_Host *instance) @@ -452,8 +402,6 @@ static irqreturn_t __init probe_intr(int irq, void *dev_id) * * Autoprobe for the IRQ line used by the NCR5380 by triggering an IRQ * and then looking to see what interrupt actually turned up. - * - * Locks: none, irqs must be enabled on entry */ static int __init __maybe_unused NCR5380_probe_irq(struct Scsi_Host *instance, @@ -503,8 +451,6 @@ static int __init __maybe_unused NCR5380_probe_irq(struct Scsi_Host *instance, * @instance: relevant scsi host instance * * For use as the host template info() handler. - * - * Locks: none */ static const char *NCR5380_info(struct Scsi_Host *instance) @@ -554,20 +500,6 @@ static void prepare_info(struct Scsi_Host *instance) } #ifdef PSEUDO_DMA -/******************************************/ -/* - * /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 - */ - static int __maybe_unused NCR5380_write_info(struct Scsi_Host *instance, char *buffer, int length) { @@ -601,8 +533,6 @@ static int __maybe_unused NCR5380_show_info(struct seq_file *m, * set correctly. I don't care about the irq and other fields. * * Returns 0 for success - * - * Locks: interrupts must be enabled when we are called */ static int NCR5380_init(struct Scsi_Host *instance, int flags) @@ -877,9 +807,6 @@ static void requeue_cmd(struct Scsi_Host *instance, struct scsi_cmnd *cmd) * 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. - * - * Locks: called as its own thread with no locks held. Takes the - * host lock and called routines may take the isa dma lock. */ static void NCR5380_main(struct work_struct *work) @@ -1077,8 +1004,6 @@ static irqreturn_t NCR5380_intr(int irq, void *dev_id) * * If failed (no target) : cmd->scsi_done() will be called, and the * cmd->result host byte set to DID_BAD_TARGET. - * - * Locks: caller holds hostdata lock in IRQ mode */ static struct scsi_cmnd *NCR5380_select(struct Scsi_Host *instance, @@ -1567,8 +1492,6 @@ timeout: * is in same phase. * * Also, *phase, *count, *data are modified in place. - * - * Locks: io_request lock held by caller */ @@ -1645,39 +1568,38 @@ static int NCR5380_transfer_dma(struct Scsi_Host *instance, unsigned char *phase } while ((tmp & BASR_PHASE_MATCH) && !(tmp & (BASR_BUSY_ERROR | BASR_END_DMA_TRANSFER))); /* - At this point, either we've completed DMA, or we have a phase mismatch, - or we've unexpectedly lost BUSY (which is a real error). - - For write DMAs, we want to wait until the last byte has been - transferred out over the bus before we turn off DMA mode. Alas, there - seems to be no terribly good way of doing this on a 5380 under all - conditions. For non-scatter-gather operations, we can wait until REQ - and ACK both go false, or until a phase mismatch occurs. Gather-writes - are nastier, since the device will be expecting more data than we - are prepared to send it, and REQ will remain asserted. On a 53C8[01] we - could test LAST BIT SENT to assure transfer (I imagine this is precisely - why this signal was added to the newer chips) but on the older 538[01] - this signal does not exist. The workaround for this lack is a watchdog; - we bail out of the wait-loop after a modest amount of wait-time if - the usual exit conditions are not met. Not a terribly clean or - correct solution :-% - - Reads are equally tricky due to a nasty characteristic of the NCR5380. - If the chip is in DMA mode for an READ, it will respond to a target's - REQ by latching the SCSI data into the INPUT DATA register and asserting - ACK, even if it has _already_ been notified by the DMA controller that - the current DMA transfer has completed! If the NCR5380 is then taken - out of DMA mode, this already-acknowledged byte is lost. - - This is not a problem for "one DMA transfer per command" reads, because - the situation will never arise... either all of the data is DMA'ed - properly, or the target switches to MESSAGE IN phase to signal a - disconnection (either operation bringing the DMA to a clean halt). - However, in order to handle scatter-reads, we must work around the - problem. The chosen fix is to DMA N-2 bytes, then check for the - condition before taking the NCR5380 out of DMA mode. One or two extra - bytes are transferred via PIO as necessary to fill out the original - request. + * At this point, either we've completed DMA, or we have a phase mismatch, + * or we've unexpectedly lost BUSY (which is a real error). + * + * For DMA sends, we want to wait until the last byte has been + * transferred out over the bus before we turn off DMA mode. Alas, there + * seems to be no terribly good way of doing this on a 5380 under all + * conditions. For non-scatter-gather operations, we can wait until REQ + * and ACK both go false, or until a phase mismatch occurs. Gather-sends + * are nastier, since the device will be expecting more data than we + * are prepared to send it, and REQ will remain asserted. On a 53C8[01] we + * could test Last Byte Sent to assure transfer (I imagine this is precisely + * why this signal was added to the newer chips) but on the older 538[01] + * this signal does not exist. The workaround for this lack is a watchdog; + * we bail out of the wait-loop after a modest amount of wait-time if + * the usual exit conditions are not met. Not a terribly clean or + * correct solution :-% + * + * DMA receive is equally tricky due to a nasty characteristic of the NCR5380. + * If the chip is in DMA receive mode, it will respond to a target's + * REQ by latching the SCSI data into the INPUT DATA register and asserting + * ACK, even if it has _already_ been notified by the DMA controller that + * the current DMA transfer has completed! If the NCR5380 is then taken + * out of DMA mode, this already-acknowledged byte is lost. This is + * not a problem for "one DMA transfer per READ command", because + * the situation will never arise... either all of the data is DMA'ed + * properly, or the target switches to MESSAGE IN phase to signal a + * disconnection (either operation bringing the DMA to a clean halt). + * However, in order to handle scatter-receive, we must work around the + * problem. The chosen fix is to DMA N-2 bytes, then check for the + * condition before taking the NCR5380 out of DMA mode. One or two extra + * bytes are transferred via PIO as necessary to fill out the original + * request. */ if (p & SR_IO) { @@ -1813,8 +1735,6 @@ static int NCR5380_transfer_dma(struct Scsi_Host *instance, unsigned char *phase * * XXX Note : we need to watch for bus free or a reset condition here * to recover from an unexpected bus free condition. - * - * Locks: io_request_lock held by caller in IRQ mode */ static void NCR5380_information_transfer(struct Scsi_Host *instance) { @@ -2009,18 +1929,10 @@ static void NCR5380_information_transfer(struct Scsi_Host *instance) { NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); break; case EXTENDED_MESSAGE: -/* - * Extended messages are sent in the following format : - * Byte - * 0 EXTENDED_MESSAGE == 1 - * 1 length (includes one byte for code, doesn't - * include first two bytes) - * 2 code - * 3..length+1 arguments - * - * Start the extended message buffer with the EXTENDED_MESSAGE - * byte, since spi_print_msg() wants the whole thing. - */ + /* + * Start the message buffer with the EXTENDED_MESSAGE + * byte, since spi_print_msg() wants the whole thing. + */ extended_msg[0] = EXTENDED_MESSAGE; /* Accept first byte by clearing ACK */ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); @@ -2142,8 +2054,6 @@ static void NCR5380_information_transfer(struct Scsi_Host *instance) { * nexus has been reestablished, * * Inputs : instance - this instance of the NCR5380. - * - * Locks: io_request_lock held by caller if IRQ driven */ static void NCR5380_reselect(struct Scsi_Host *instance) { diff --git a/drivers/scsi/atari_NCR5380.c b/drivers/scsi/atari_NCR5380.c index a01921d..aeaeea5 100644 --- a/drivers/scsi/atari_NCR5380.c +++ b/drivers/scsi/atari_NCR5380.c @@ -24,47 +24,7 @@ * 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. - * - */ +/* Ported to Atari by Roman Hodek and others. */ /* Adapted for the sun3 by Sam Creasey. */ @@ -344,17 +304,15 @@ static void free_all_tags(struct NCR5380_hostdata *hostdata) #endif /* SUPPORT_TAGS */ - -/* - * Function: void merge_contiguous_buffers( struct 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: struct scsi_cmnd *cmd - * The command to work on. The first scatter buffer's data are - * assumed to be already transferred into ptr/this_residual. +/** + * merge_contiguous_buffers - coalesce scatter-gather list entries + * @cmd: command requesting IO + * + * Try to merge several scatter-gather buffers into one DMA transfer. + * This is possible if the scatter buffers lie on physically + * contiguous addresses. The first scatter-gather buffer's data are + * assumed to be already transferred into cmd->SCp.this_residual. + * Every buffer merged avoids an interrupt and a DMA setup operation. */ static void merge_contiguous_buffers(struct scsi_cmnd *cmd) @@ -406,9 +364,7 @@ static inline void initialize_SCp(struct scsi_cmnd *cmd) cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 1; cmd->SCp.ptr = sg_virt(cmd->SCp.buffer); 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; @@ -556,8 +512,6 @@ static struct { * @instance: adapter to dump * * Print the current SCSI phase for debugging purposes - * - * Locks: none */ static void NCR5380_print_phase(struct Scsi_Host *instance) @@ -583,8 +537,6 @@ static void NCR5380_print_phase(struct Scsi_Host *instance) * @instance: relevant scsi host instance * * For use as the host template info() handler. - * - * Locks: none */ static const char *NCR5380_info(struct Scsi_Host *instance) @@ -829,20 +781,6 @@ static int NCR5380_queue_command(struct Scsi_Host *instance, 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. - */ - - /* ++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. @@ -958,8 +896,6 @@ static void requeue_cmd(struct Scsi_Host *instance, struct scsi_cmnd *cmd) * 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. - * - * Locks: called as its own thread with no locks held. */ static void NCR5380_main(struct work_struct *work) @@ -1041,7 +977,6 @@ static void NCR5380_main(struct work_struct *work) * mismatch occurs (which would finish the DMA transfer). * * Inputs : instance - this instance of the NCR5380. - * */ static void NCR5380_dma_complete(struct Scsi_Host *instance) @@ -1766,7 +1701,6 @@ timeout: * is in same phase. * * Also, *phase, *count, *data are modified in place. - * */ @@ -1968,9 +1902,6 @@ static void NCR5380_information_transfer(struct Scsi_Host *instance) --cmd->SCp.buffers_residual; cmd->SCp.this_residual = cmd->SCp.buffer->length; cmd->SCp.ptr = sg_virt(cmd->SCp.buffer); - /* ++roman: Try to merge some scatter-buffers if - * they are at contiguous physical addresses. - */ merge_contiguous_buffers(cmd); dsprintk(NDEBUG_INFORMATION, instance, "%d bytes and %d buffers left\n", cmd->SCp.this_residual, @@ -2007,7 +1938,8 @@ static void NCR5380_information_transfer(struct Scsi_Host *instance) /* * If the watchdog timer fires, all future * accesses to this device will use the - * polled-IO. */ + * polled-IO. + */ scmd_printk(KERN_INFO, cmd, "switching to slow handshake\n"); cmd->device->borken = 1; @@ -2099,10 +2031,6 @@ static void NCR5380_information_transfer(struct Scsi_Host *instance) /* Enable reselect interrupts */ NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask); - /* ++roman: For Falcon SCSI, release the lock on the - * ST-DMA here if no other commands are waiting on the - * disconnected queue. - */ maybe_release_dma_irq(instance); return; case MESSAGE_REJECT: @@ -2164,15 +2092,7 @@ static void NCR5380_information_transfer(struct Scsi_Host *instance) break; case EXTENDED_MESSAGE: /* - * Extended messages are sent in the following format : - * Byte - * 0 EXTENDED_MESSAGE == 1 - * 1 length (includes one byte for code, doesn't - * include first two bytes) - * 2 code - * 3..length+1 arguments - * - * Start the extended message buffer with the EXTENDED_MESSAGE + * Start the message buffer with the EXTENDED_MESSAGE * byte, since spi_print_msg() wants the whole thing. */ extended_msg[0] = EXTENDED_MESSAGE; @@ -2299,7 +2219,6 @@ static void NCR5380_information_transfer(struct Scsi_Host *instance) * nexus has been reestablished, * * Inputs : instance - this instance of the NCR5380. - * */ |