Aic79xx Driver Upate

 o Switch to handling bad SCSI status as a sequencer interrupt
   instead of having the kernel proccess these failures via
   the completion queue.  This is done because:

    - The old scheme required us to pause the sequencer and clear
      critical sections for each SCB.  It seems that these pause
      actions, if coincident with a sequencer FIFO interrupt, would
      result in a FIFO interrupt getting lost or directing to the
      wrong FIFO.  This caused hangs when the driver was stressed
      under high "queue full" loads.
    - The completion code assumed that it was always called with
      the sequencer running.  This may not be the case in timeout
      processing where completions occur manually via
      ahd_pause_and_flushwork().
    - With this scheme, the extra expense of clearing critical
      sections is avoided since the sequencer will only self pause
      once all pending selections have cleared and it is not in
      a critical section.

drivers/scsi/aic7xxx/aic79xx.reg

@@ -39,7 +39,7 @@
  *
  * $FreeBSD$
  */
-VERSION = "$Id: //depot/aic7xxx/aic7xxx/aic79xx.reg#66 $"
+VERSION = "$Id: //depot/aic7xxx/aic7xxx/aic79xx.reg#67 $"
 
 /*
  * This file is processed by the aic7xxx_asm utility for use in assembling
@@ -194,7 +194,8 @@ register SEQINTCODE {
 		TRACEPOINT1,
 		TRACEPOINT2,
 		TRACEPOINT3,
-		SAW_HWERR
+		SAW_HWERR,
+		BAD_SCB_STATUS
 	}
 }
 

drivers/scsi/aic7xxx/aic79xx.seq

@@ -40,7 +40,7 @@
  * $FreeBSD$
  */
 
-VERSION = "$Id: //depot/aic7xxx/aic7xxx/aic79xx.seq#90 $"
+VERSION = "$Id: //depot/aic7xxx/aic7xxx/aic79xx.seq#91 $"
 PATCH_ARG_LIST = "struct ahd_softc *ahd"
 PREFIX = "ahd_"
 
@@ -175,12 +175,31 @@ END_CRITICAL;
 scbdma_tohost_done:
 	test	CCSCBCTL, CCARREN jz fill_qoutfifo_dmadone;
 	/*
-	 * A complete SCB upload requires no intervention.
-	 * The SCB is already on the COMPLETE_SCB list
-	 * and its completion notification will now be
-	 * handled just like any other SCB.
+	 * An SCB has been succesfully uploaded to the host.
+	 * If the SCB was uploaded for some reason other than
+	 * bad SCSI status (currently only for underruns), we
+	 * queue the SCB for normal completion.  Otherwise, we
+	 * wait until any select-out activity has halted, and
+	 * then notify the host so that the transaction can be
+	 * dealt with.
 	 */
-	and	CCSCBCTL, ~(CCARREN|CCSCBEN) ret;
+	test	SCB_SCSI_STATUS, 0xff jnz scbdma_notify_host;
+	and	CCSCBCTL, ~(CCARREN|CCSCBEN);
+	bmov	COMPLETE_DMA_SCB_HEAD, SCB_NEXT_COMPLETE, 2;
+	bmov	SCB_NEXT_COMPLETE, COMPLETE_SCB_HEAD, 2;
+	bmov	COMPLETE_SCB_HEAD, SCBPTR, 2 ret;
+scbdma_notify_host:
+	SET_MODE(M_SCSI, M_SCSI)
+	test	SCSISEQ0, ENSELO jnz return;
+	test	SSTAT0, (SELDO|SELINGO) jnz return;
+	SET_MODE(M_CCHAN, M_CCHAN)
+	/*
+	 * Remove SCB and notify host.
+	 */
+	and	CCSCBCTL, ~(CCARREN|CCSCBEN);
+	bmov	COMPLETE_DMA_SCB_HEAD, SCB_NEXT_COMPLETE, 2;
+	SET_SEQINTCODE(BAD_SCB_STATUS)
+	ret;
 fill_qoutfifo_dmadone:
 	and	CCSCBCTL, ~(CCARREN|CCSCBEN);
 	call	qoutfifo_updated;
@@ -325,15 +344,7 @@ fetch_new_scb:
 dma_complete_scb:
 	bmov	SCBPTR, COMPLETE_DMA_SCB_HEAD, 2;
 	bmov	SCBHADDR, SCB_BUSADDR, 4;
-	mvi	CCARREN|CCSCBEN|CCSCBRESET call dma_scb;
-	/*
-	 * Now that we've started the DMA, push us onto
-	 * the normal completion queue to have our SCBID
-	 * posted to the kernel.
-	 */
-	bmov	COMPLETE_DMA_SCB_HEAD, SCB_NEXT_COMPLETE, 2;
-	bmov	SCB_NEXT_COMPLETE, COMPLETE_SCB_HEAD, 2;
-	bmov	COMPLETE_SCB_HEAD, SCBPTR, 2 ret;
+	mvi	CCARREN|CCSCBEN|CCSCBRESET jmp dma_scb;
 END_CRITICAL;
 
 /*
@@ -1615,25 +1626,32 @@ export seq_isr:
 		 * and deffer the test by one instruction.
 		 */
 		mov	REG_ISR, LQISTAT2;
-		test	REG_ISR, LQIWORKONLQ jz data_valid;
-		test	SEQINTSRC, SAVEPTRS  jz data_valid;
+		test	REG_ISR, LQIWORKONLQ jz main_isr;
+		test	SEQINTSRC, SAVEPTRS  jz main_isr;
 		test	LONGJMP_ADDR[1], INVALID_ADDR jz saveptr_active_fifo;
 		/*
-		 * Switch to the active FIFO.
+		 * Switch to the active FIFO after clearing the snapshot
+		 * savepointer in the current FIFO.  We do this so that
+		 * a pending CTXTDONE or SAVEPTR is visible in the active
+		 * FIFO.  This status is the only way we can detect if we
+		 * have lost the race (e.g. host paused us) and our attepts
+		 * to disable the channel occurred after all REQs were
+		 * already seen and acked (REQINIT never comes true).
 		 */
+		mvi	DFFSXFRCTL, CLRCHN;
 		xor	MODE_PTR, MK_MODE(M_DFF1, M_DFF1);
-		test	DFCNTRL, DIRECTION jz snapshot_other_fifo;
+		test	DFCNTRL, DIRECTION jz interrupt_return;
 		and	DFCNTRL, ~SCSIEN;
-		test	SSTAT1, REQINIT	jz .;
+snapshot_wait_data_valid:
+		test	SEQINTSRC, (CTXTDONE|SAVEPTRS) jnz snapshot_data_valid;
+		test	SSTAT1, REQINIT	jz snapshot_wait_data_valid;
+snapshot_data_valid:
 		or	DFCNTRL, SCSIEN;
-		/* FALLTHROUGH */
-snapshot_other_fifo:
-		xor	MODE_PTR, MK_MODE(M_DFF1, M_DFF1);
-		/* FALLTHROUGH */
+		or	SEQINTCTL, IRET ret;
 snapshot_saveptr:
 		mvi	DFFSXFRCTL, CLRCHN;
 		or	SEQINTCTL, IRET ret;
-data_valid:
+main_isr:
 	}
 	test	SEQINTSRC, CFG4DATA	jnz cfg4data_intr;
 	test	SEQINTSRC, CFG4ISTAT	jnz cfg4istat_intr;
@@ -1666,10 +1684,11 @@ saveptr_active_fifo:
 	or	SEQINTCTL, IRET ret;
 
 cfg4data_intr:
-	inc	SCB_FIFO_USE_COUNT;
-	test	SCB_SGPTR[0], SG_LIST_NULL jnz pkt_handle_overrun;
+	test	SCB_SGPTR[0], SG_LIST_NULL jnz pkt_handle_overrun_inc_use_count;
 	call	load_first_seg;
 	call	pkt_handle_xfer;
+	inc	SCB_FIFO_USE_COUNT;
+interrupt_return:
 	or	SEQINTCTL, IRET ret;
 
 cfg4istat_intr:
@@ -1961,6 +1980,8 @@ illegal_phase:
  * data.  Otherwise use an overrun buffer in the host to simulate
  * BITBUCKET.
  */
+pkt_handle_overrun_inc_use_count:
+	inc	SCB_FIFO_USE_COUNT;
 pkt_handle_overrun:
 	SET_SEQINTCODE(CFG4OVERRUN)
 	call	freeze_queue;
@@ -1987,8 +2008,8 @@ pkt_overrun_end:
 	or	SCB_RESIDUAL_SGPTR, SG_OVERRUN_RESID;
 	test	SEQINTSRC, CTXTDONE jz unexpected_nonpkt_phase;
 	dec	SCB_FIFO_USE_COUNT;
-	test	SCB_CONTROL, STATUS_RCVD jnz pkt_complete_scb_if_fifos_idle;
 	or	LONGJMP_ADDR[1], INVALID_ADDR;
+	test	SCB_CONTROL, STATUS_RCVD jnz pkt_complete_scb_if_fifos_idle;
 	mvi	DFFSXFRCTL, CLRCHN ret;
 
 if ((ahd->bugs & AHD_PKT_BITBUCKET_BUG) != 0) {

drivers/scsi/aic7xxx/aic79xx_core.c

@@ -37,7 +37,7 @@
  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  * POSSIBILITY OF SUCH DAMAGES.
  *
- * $Id: //depot/aic7xxx/aic7xxx/aic79xx.c#186 $
+ * $Id: //depot/aic7xxx/aic7xxx/aic79xx.c#189 $
  *
  * $FreeBSD$
  */
@@ -556,6 +556,26 @@ ahd_handle_seqint(struct ahd_softc *ahd, u_int intstat)
 		       ahd_name(ahd), seqintcode);
 #endif
 	switch (seqintcode) {
+	case BAD_SCB_STATUS:
+	{
+		struct	scb *scb;
+		u_int	scbid;
+		int	cmds_pending;
+
+		scbid = ahd_get_scbptr(ahd);
+		scb = ahd_lookup_scb(ahd, scbid);
+		if (scb != NULL) {
+			ahd_complete_scb(ahd, scb);
+		} else {
+			printf("%s: WARNING no command for scb %d "
+			       "(bad status)\n", ahd_name(ahd), scbid);
+			ahd_dump_card_state(ahd);
+		}
+		cmds_pending = ahd_inw(ahd, CMDS_PENDING);
+		if (cmds_pending > 0)
+			ahd_outw(ahd, CMDS_PENDING, cmds_pending - 1);
+		break;
+	}
 	case ENTERING_NONPACK:
 	{
 		struct	scb *scb;
@@ -7742,7 +7762,6 @@ ahd_handle_scsi_status(struct ahd_softc *ahd, struct scb *scb)
 {
 	struct hardware_scb *hscb;
 	u_int  qfreeze_cnt;
-	u_int  maxloops;
 
 	/*
 	 * The sequencer freezes its select-out queue
@@ -7752,25 +7771,6 @@ ahd_handle_scsi_status(struct ahd_softc *ahd, struct scb *scb)
 	 */
 	hscb = scb->hscb; 
 
-	/*
-	 * Wait until any pending selections have been processed.
-	 */
-	maxloops = 1000;
-	do {
-		ahd_pause(ahd);
-		ahd_clear_critical_section(ahd);
-		ahd_set_modes(ahd, AHD_MODE_SCSI, AHD_MODE_SCSI);
-		if (((ahd_inb(ahd, SCSISEQ0) & ENSELO) == 0
-		  && (ahd_inb(ahd, SSTAT0) & (SELDO|SELINGO)) == 0)
-		 || (ahd_inb(ahd, SSTAT1) & SELTO) != 0)
-			break;
-		ahd_unpause(ahd);
-		ahd_delay(200);
-	} while (--maxloops);
-
-	if (maxloops == 0)
-		ahd_pause(ahd);
-
 	/* Freeze the queue until the client sees the error. */
 	ahd_freeze_devq(ahd, scb);
 	ahd_freeze_scb(scb);
@@ -7784,7 +7784,7 @@ ahd_handle_scsi_status(struct ahd_softc *ahd, struct scb *scb)
 	if (qfreeze_cnt == 0)
 		ahd_outb(ahd, SEQ_FLAGS2,
 			 ahd_inb(ahd, SEQ_FLAGS2) & ~SELECTOUT_QFROZEN);
-	ahd_unpause(ahd);
+
 	/* Don't want to clobber the original sense code */
 	if ((scb->flags & SCB_SENSE) != 0) {
 		/*

drivers/scsi/aic7xxx/aic79xx_inline.h

@@ -37,7 +37,7 @@
  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  * POSSIBILITY OF SUCH DAMAGES.
  *
- * $Id: //depot/aic7xxx/aic7xxx/aic79xx_inline.h#44 $
+ * $Id: //depot/aic7xxx/aic7xxx/aic79xx_inline.h#45 $
  *
  * $FreeBSD$
  */
@@ -223,7 +223,7 @@ ahd_unpause(struct ahd_softc *ahd)
 		ahd_set_modes(ahd, ahd->saved_src_mode, ahd->saved_dst_mode);
 	}
 
-	if ((ahd_inb(ahd, INTSTAT) & ~(SWTMINT | CMDCMPLT)) == 0)
+	if ((ahd_inb(ahd, INTSTAT) & ~CMDCMPLT) == 0)
 		ahd_outb(ahd, HCNTRL, ahd->unpause);
 
 	ahd_known_modes(ahd, AHD_MODE_UNKNOWN, AHD_MODE_UNKNOWN);

drivers/scsi/aic7xxx/aic79xx_osm.c

 /*
  * Adaptec AIC79xx device driver for Linux.
  *
- * $Id: //depot/aic7xxx/linux/drivers/scsi/aic7xxx/aic79xx_osm.c#154 $
+ * $Id: //depot/aic7xxx/linux/drivers/scsi/aic7xxx/aic79xx_osm.c#155 $
  *
  * --------------------------------------------------------------------------
  * Copyright (c) 1994-2000 Justin T. Gibbs.
@@ -2070,7 +2070,6 @@ aic79xx_setup(char *s)
 			s = aic_parse_brace_option("tag_info", p + n, end,
 			    2, ahd_linux_setup_tag_info, 0);
 		} else if (strncmp(p, "rd_strm", n) == 0) {
-			printf("Calling brace parse for %s\n", p);
 			s = aic_parse_brace_option("rd_strm", p + n, end,
 			    1, ahd_linux_setup_rd_strm_info, 0);
 		} else if (strncmp(p, "dv", n) == 0) {

drivers/scsi/aic7xxx/aic79xx_reg.h_shipped

@@ -2,8 +2,8 @@
  * DO NOT EDIT - This file is automatically generated
  *		 from the following source files:
  *
- * $Id: //depot/aic7xxx/aic7xxx/aic79xx.seq#90 $
- * $Id: //depot/aic7xxx/aic7xxx/aic79xx.reg#66 $
+ * $Id: //depot/aic7xxx/aic7xxx/aic79xx.seq#91 $
+ * $Id: //depot/aic7xxx/aic7xxx/aic79xx.reg#67 $
  */
 typedef int (ahd_reg_print_t)(u_int, u_int *, u_int);
 typedef struct ahd_reg_parse_entry {
@@ -2360,6 +2360,7 @@ ahd_reg_print_t ahd_scb_disconnected_lists_print;
 #define		SPLTINT         	0x01
 
 #define	SEQINTCODE      		0x02
+#define		BAD_SCB_STATUS  	0x1a
 #define		SAW_HWERR       	0x19
 #define		TRACEPOINT3     	0x18
 #define		TRACEPOINT2     	0x17
@@ -3767,5 +3768,5 @@ ahd_reg_print_t ahd_scb_disconnected_lists_print;
 
 
 /* Exported Labels */
-#define	LABEL_seq_isr 	0x264
-#define	LABEL_timer_isr	0x260
+#define	LABEL_seq_isr 	0x270
+#define	LABEL_timer_isr	0x26c

drivers/scsi/aic7xxx/aic79xx_reg_print.c_shipped

@@ -2,8 +2,8 @@
  * DO NOT EDIT - This file is automatically generated
  *		 from the following source files:
  *
- * $Id: //depot/aic7xxx/aic7xxx/aic79xx.seq#90 $
- * $Id: //depot/aic7xxx/aic7xxx/aic79xx.reg#66 $
+ * $Id: //depot/aic7xxx/aic7xxx/aic79xx.seq#91 $
+ * $Id: //depot/aic7xxx/aic7xxx/aic79xx.reg#67 $
  */
 
 #include "aic79xx_osm.h"
@@ -65,13 +65,14 @@ static ahd_reg_parse_entry_t SEQINTCODE_parse_table[] = {
 	{ "TRACEPOINT1",	0x16, 0xff },
 	{ "TRACEPOINT2",	0x17, 0xff },
 	{ "TRACEPOINT3",	0x18, 0xff },
-	{ "SAW_HWERR",		0x19, 0xff }
+	{ "SAW_HWERR",		0x19, 0xff },
+	{ "BAD_SCB_STATUS",	0x1a, 0xff }
 };
 
 int
 ahd_seqintcode_print(u_int regvalue, u_int *cur_col, u_int wrap)
 {
-	return (ahd_print_register(SEQINTCODE_parse_table, 26, "SEQINTCODE",
+	return (ahd_print_register(SEQINTCODE_parse_table, 27, "SEQINTCODE",
 	    0x02, regvalue, cur_col, wrap));
 }