svn commit: r322980 - head/sys/dev/ntb/ntb_hw

[Alexander Motin]

Author: mav
Date: Mon Aug 28 19:52:57 2017
New Revision: 322980
URL: https://svnweb.freebsd.org/changeset/base/322980

Log:
  Fix fake interrupt when set doorbell is unmasked.
  
  Since the doorbell bit is already set when interrupt handler is called,
  the event was not propagated to upper layer.  It was working normally
  because present code was not using masking actively, but that is going
  to change.
  
  MFC after:	2 weeks
  Sponsored by:	iXsystems, Inc.

Modified:
  head/sys/dev/ntb/ntb_hw/ntb_hw.c

Modified: head/sys/dev/ntb/ntb_hw/ntb_hw.c
==============================================================================
--- head/sys/dev/ntb/ntb_hw/ntb_hw.c	Mon Aug 28 19:34:39 2017	(r322979)
+++ head/sys/dev/ntb/ntb_hw/ntb_hw.c	Mon Aug 28 19:52:57 2017	(r322980)
@@ -253,7 +253,8 @@ struct ntb_softc {
 	uint64_t			db_valid_mask;
 	uint64_t			db_link_mask;
 	uint64_t			db_mask;
-	uint64_t			fake_db_bell;	/* NTB_SB01BASE_LOCKUP*/
+	uint64_t			fake_db;	/* NTB_SB01BASE_LOCKUP*/
+	uint64_t			force_db;	/* NTB_SB01BASE_LOCKUP*/
 
 	int				last_ts;	/* ticks @ last irq */
 
@@ -1206,10 +1207,11 @@ intel_ntb_db_clear_mask(device_t dev, uint64_t bits)
 	     (uintmax_t)ntb->db_valid_mask));
 
 	DB_MASK_LOCK(ntb);
-	ibits = ntb->fake_db_bell & ntb->db_mask & bits;
+	ibits = ntb->fake_db & ntb->db_mask & bits;
 	ntb->db_mask &= ~bits;
 	if (HAS_FEATURE(ntb, NTB_SB01BASE_LOCKUP)) {
 		/* Simulate fake interrupts if unmasked DB bits are set. */
+		ntb->force_db |= ibits;
 		for (i = 0; i < XEON_NONLINK_DB_MSIX_BITS; i++) {
 			if ((ibits & intel_ntb_db_vector_mask(dev, i)) != 0)
 				swi_sched(ntb->int_info[i].tag, 0);
@@ -1226,7 +1228,7 @@ intel_ntb_db_read(device_t dev)
 	struct ntb_softc *ntb = device_get_softc(dev);
 
 	if (HAS_FEATURE(ntb, NTB_SB01BASE_LOCKUP))
-		return (ntb->fake_db_bell);
+		return (ntb->fake_db);
 
 	return (db_ioread(ntb, ntb->self_reg->db_bell));
 }
@@ -1243,7 +1245,7 @@ intel_ntb_db_clear(device_t dev, uint64_t bits)
 
 	if (HAS_FEATURE(ntb, NTB_SB01BASE_LOCKUP)) {
 		DB_MASK_LOCK(ntb);
-		ntb->fake_db_bell &= ~bits;
+		ntb->fake_db &= ~bits;
 		DB_MASK_UNLOCK(ntb);
 		return;
 	}
@@ -1291,11 +1293,16 @@ intel_ntb_interrupt(struct ntb_softc *ntb, uint32_t ve
 	    (vec_mask & ntb->db_link_mask) == 0) {
 		DB_MASK_LOCK(ntb);
 
-		/* Do not report same DB events again if not cleared yet. */
-		vec_mask &= ~ntb->fake_db_bell;
+		/*
+		 * Do not report same DB events again if not cleared yet,
+		 * unless the mask was just cleared for them and this
+		 * interrupt handler call can be the consequence of it.
+		 */
+		vec_mask &= ~ntb->fake_db | ntb->force_db;
+		ntb->force_db &= ~vec_mask;
 
 		/* Update our internal doorbell register. */
-		ntb->fake_db_bell |= vec_mask;
+		ntb->fake_db |= vec_mask;
 
 		/* Do not report masked DB events. */
 		vec_mask &= ~ntb->db_mask;
@@ -1512,7 +1519,7 @@ intel_ntb_xeon_init_dev(struct ntb_softc *ntb)
 	ntb->xlat_reg = &xeon_sec_xlat;
 
 	if (HAS_FEATURE(ntb, NTB_SB01BASE_LOCKUP)) {
-		ntb->fake_db_bell = 0;
+		ntb->force_db = ntb->fake_db = 0;
 		ntb->msix_mw_idx = (ntb->mw_count + g_ntb_msix_idx) %
 		    ntb->mw_count;
 		intel_ntb_printf(2, "Setting up MSIX mw idx %d means %u\n",