svn commit: r352906 - in head/sys: dev/vmware/vmxnet3 net

[Mark Johnston]

Author: markj
Date: Mon Sep 30 15:59:07 2019
New Revision: 352906
URL: https://svnweb.freebsd.org/changeset/base/352906

Log:
  Add IFLIB_SINGLE_IRQ_RX_ONLY.
  
  As of r347221 the iflib legacy interrupt mode setup assumes that drivers
  perform both receive and transmit processing from the interrupt handler.
  This assumption is invalid in the vmxnet3 driver, so introduce the
  IFLIB_SINGLE_IRQ_RX_ONLY flag to make iflib avoid tx processing in the
  interrupt handler.
  
  PR:		239118
  Reported and tested by:	Juraj Lutter <otis at sk.freebsd.org>
  Obtained from:	marius
  Reviewed by:	gallatin
  MFC after:	3 days
  Differential Revision:	https://reviews.freebsd.org/D21831

Modified:
  head/sys/dev/vmware/vmxnet3/if_vmx.c
  head/sys/net/iflib.c
  head/sys/net/iflib.h

Modified: head/sys/dev/vmware/vmxnet3/if_vmx.c
==============================================================================
--- head/sys/dev/vmware/vmxnet3/if_vmx.c	Mon Sep 30 15:08:45 2019	(r352905)
+++ head/sys/dev/vmware/vmxnet3/if_vmx.c	Mon Sep 30 15:59:07 2019	(r352906)
@@ -287,7 +287,7 @@ static struct if_shared_ctx vmxnet3_sctx_init = {
 	.isc_vendor_info = vmxnet3_vendor_info_array,
 	.isc_driver_version = "2",
 	.isc_driver = &vmxnet3_iflib_driver,
-	.isc_flags = IFLIB_HAS_RXCQ | IFLIB_HAS_TXCQ,
+	.isc_flags = IFLIB_HAS_RXCQ | IFLIB_HAS_TXCQ | IFLIB_SINGLE_IRQ_RX_ONLY,
 
 	/*
 	 * Number of receive queues per receive queue set, with associated

Modified: head/sys/net/iflib.c
==============================================================================
--- head/sys/net/iflib.c	Mon Sep 30 15:08:45 2019	(r352905)
+++ head/sys/net/iflib.c	Mon Sep 30 15:59:07 2019	(r352906)
@@ -6059,6 +6059,7 @@ iflib_legacy_setup(if_ctx_t ctx, driver_filter_t filte
 	gtask_fn_t *fn;
 	void *q;
 	int err, tqrid;
+	bool rx_only;
 
 	q = &ctx->ifc_rxqs[0];
 	info = &rxq[0].ifr_filter_info;
@@ -6066,17 +6067,19 @@ iflib_legacy_setup(if_ctx_t ctx, driver_filter_t filte
 	tqg = qgroup_if_io_tqg;
 	tqrid = *rid;
 	fn = _task_fn_rx;
+	rx_only = (ctx->ifc_sctx->isc_flags & IFLIB_SINGLE_IRQ_RX_ONLY) != 0;
 
 	ctx->ifc_flags |= IFC_LEGACY;
 	info->ifi_filter = filter;
 	info->ifi_filter_arg = filter_arg;
 	info->ifi_task = gtask;
-	info->ifi_ctx = q;
+	info->ifi_ctx = rx_only ? ctx : q;
 
 	dev = ctx->ifc_dev;
 	/* We allocate a single interrupt resource */
-	if ((err = _iflib_irq_alloc(ctx, irq, tqrid, iflib_fast_intr_rxtx,
-	    NULL, info, name)) != 0)
+	err = _iflib_irq_alloc(ctx, irq, tqrid, rx_only ? iflib_fast_intr_ctx :
+	    iflib_fast_intr_rxtx, NULL, info, name);
+	if (err != 0)
 		return (err);
 	GROUPTASK_INIT(gtask, 0, fn, q);
 	res = irq->ii_res;

Modified: head/sys/net/iflib.h
==============================================================================
--- head/sys/net/iflib.h	Mon Sep 30 15:08:45 2019	(r352905)
+++ head/sys/net/iflib.h	Mon Sep 30 15:59:07 2019	(r352906)
@@ -366,6 +366,11 @@ typedef enum {
  * Driver will pass the media
  */
 #define IFLIB_DRIVER_MEDIA	0x20000
+/*
+ * When using a single hardware interrupt for the interface, only process RX
+ * interrupts instead of doing combined RX/TX processing.
+ */
+#define	IFLIB_SINGLE_IRQ_RX_ONLY	0x40000
 
 /*
  * field accessors