svn commit: r339382 - projects/power8_bringup_hacks/sys/dev/bge

[Leandro Lupori]

Author: luporl
Date: Tue Oct 16 16:36:02 2018
New Revision: 339382
URL: https://svnweb.freebsd.org/changeset/base/339382

Log:
  bge(4): limit DMA address to 2GB
  
  This is a temporary hack, to avoid POWER8 Broadcom NICs from becoming
  unusable after transferring a reasonable amount of data.
  The issue is the same as that of AHCI, where DMA addresses above 2GB
  do not work and causes PCI errors.

Modified:
  projects/power8_bringup_hacks/sys/dev/bge/if_bge.c

Modified: projects/power8_bringup_hacks/sys/dev/bge/if_bge.c
==============================================================================
--- projects/power8_bringup_hacks/sys/dev/bge/if_bge.c	Tue Oct 16 16:03:17 2018	(r339381)
+++ projects/power8_bringup_hacks/sys/dev/bge/if_bge.c	Tue Oct 16 16:36:02 2018	(r339382)
@@ -134,6 +134,8 @@ MODULE_DEPEND(bge, miibus, 1, 1, 1);
 /* "device miibus" required.  See GENERIC if you get errors here. */
 #include "miibus_if.h"
 
+#define BGE_BUS_SPACE_MAXADDR_32BIT	0x7FFFFFFFU
+
 /*
  * Various supported device vendors/types and their names. Note: the
  * spec seems to indicate that the hardware still has Alteon's vendor
@@ -3050,15 +3052,16 @@ bge_dma_alloc(struct bge_softc *sc)
 
 	/* Create parent tag for buffers. */
 	if ((sc->bge_flags & BGE_FLAG_4G_BNDRY_BUG) != 0) {
+		lowaddr = BGE_BUS_SPACE_MAXADDR_32BIT;
 		/*
 		 * XXX
 		 * watchdog timeout issue was observed on BCM5704 which
 		 * lives behind PCI-X bridge(e.g AMD 8131 PCI-X bridge).
 		 * Both limiting DMA address space to 32bits and flushing
 		 * mailbox write seem to address the issue.
-		 */
 		if (sc->bge_pcixcap != 0)
 			lowaddr = BUS_SPACE_MAXADDR_32BIT;
+		*/
 	}
 	error = bus_dma_tag_create(bus_get_dma_tag(sc->bge_dev), 1, 0, lowaddr,
 	    BUS_SPACE_MAXADDR, NULL, NULL, BUS_SPACE_MAXSIZE_32BIT, 0,