diff options
Diffstat (limited to 'drivers/scsi/NCR5380.c')
| -rw-r--r-- | drivers/scsi/NCR5380.c | 170 |
1 files changed, 40 insertions, 130 deletions
diff --git a/drivers/scsi/NCR5380.c b/drivers/scsi/NCR5380.c index 38b03af36a6a..b968b3012e27 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) { |