svn commit: r280866 - in head/sys: amd64/amd64 i386/i386

[John Baldwin]

Author: jhb
Date: Mon Mar 30 20:13:22 2015
New Revision: 280866
URL: https://svnweb.freebsd.org/changeset/base/280866

Log:
  Wait 100 microseconds for a local APIC to dispatch each startup-related IPI
  rather than 20.  The MP 1.4 specification states in Appendix B.2:
  
    "A period of 20 microseconds should be sufficient for IPI dispatch to
     complete under normal operating conditions".
  
  (Note that this appears to be separate from the 10 millisecond (INIT) and
  200 microsecond (STARTUP) waits after the IPIs are dispatched.)  The
  Intel SDM is silent on this issue as far as I can tell.
  
  At least some hardware requires 60 microseconds as noted in the PR, so
  bump this to 100 to be on the safe side.
  
  PR:		197756
  Reported by:	zaphod at berentweb.com
  MFC after:	1 week

Modified:
  head/sys/amd64/amd64/mp_machdep.c
  head/sys/i386/i386/mp_machdep.c

Modified: head/sys/amd64/amd64/mp_machdep.c
==============================================================================
--- head/sys/amd64/amd64/mp_machdep.c	Mon Mar 30 20:01:41 2015	(r280865)
+++ head/sys/amd64/amd64/mp_machdep.c	Mon Mar 30 20:13:22 2015	(r280866)
@@ -1084,7 +1084,7 @@ ipi_startup(int apic_id, int vector)
 	 */
 	lapic_ipi_raw(APIC_DEST_DESTFLD | APIC_TRIGMOD_LEVEL |
 	    APIC_LEVEL_ASSERT | APIC_DESTMODE_PHY | APIC_DELMODE_INIT, apic_id);
-	lapic_ipi_wait(20);
+	lapic_ipi_wait(100);
 
 	/* Explicitly deassert the INIT IPI. */
 	lapic_ipi_raw(APIC_DEST_DESTFLD | APIC_TRIGMOD_LEVEL |
@@ -1104,7 +1104,7 @@ ipi_startup(int apic_id, int vector)
 	lapic_ipi_raw(APIC_DEST_DESTFLD | APIC_TRIGMOD_EDGE |
 	    APIC_LEVEL_ASSERT | APIC_DESTMODE_PHY | APIC_DELMODE_STARTUP |
 	    vector, apic_id);
-	if (!lapic_ipi_wait(20))
+	if (!lapic_ipi_wait(100))
 		panic("Failed to deliver first STARTUP IPI to APIC %d",
 		    apic_id);
 	DELAY(200);		/* wait ~200uS */
@@ -1118,7 +1118,7 @@ ipi_startup(int apic_id, int vector)
 	lapic_ipi_raw(APIC_DEST_DESTFLD | APIC_TRIGMOD_EDGE |
 	    APIC_LEVEL_ASSERT | APIC_DESTMODE_PHY | APIC_DELMODE_STARTUP |
 	    vector, apic_id);
-	if (!lapic_ipi_wait(20))
+	if (!lapic_ipi_wait(100))
 		panic("Failed to deliver second STARTUP IPI to APIC %d",
 		    apic_id);
 

Modified: head/sys/i386/i386/mp_machdep.c
==============================================================================
--- head/sys/i386/i386/mp_machdep.c	Mon Mar 30 20:01:41 2015	(r280865)
+++ head/sys/i386/i386/mp_machdep.c	Mon Mar 30 20:13:22 2015	(r280866)
@@ -1157,7 +1157,7 @@ ipi_startup(int apic_id, int vector)
 	 */
 	lapic_ipi_raw(APIC_DEST_DESTFLD | APIC_TRIGMOD_LEVEL |
 	    APIC_LEVEL_ASSERT | APIC_DESTMODE_PHY | APIC_DELMODE_INIT, apic_id);
-	lapic_ipi_wait(20);
+	lapic_ipi_wait(100);
 
 	/* Explicitly deassert the INIT IPI. */
 	lapic_ipi_raw(APIC_DEST_DESTFLD | APIC_TRIGMOD_LEVEL |
@@ -1177,7 +1177,7 @@ ipi_startup(int apic_id, int vector)
 	lapic_ipi_raw(APIC_DEST_DESTFLD | APIC_TRIGMOD_EDGE |
 	    APIC_LEVEL_ASSERT | APIC_DESTMODE_PHY | APIC_DELMODE_STARTUP |
 	    vector, apic_id);
-	if (!lapic_ipi_wait(20))
+	if (!lapic_ipi_wait(100))
 		panic("Failed to deliver first STARTUP IPI to APIC %d",
 		    apic_id);
 	DELAY(200);		/* wait ~200uS */
@@ -1191,7 +1191,7 @@ ipi_startup(int apic_id, int vector)
 	lapic_ipi_raw(APIC_DEST_DESTFLD | APIC_TRIGMOD_EDGE |
 	    APIC_LEVEL_ASSERT | APIC_DESTMODE_PHY | APIC_DELMODE_STARTUP |
 	    vector, apic_id);
-	if (!lapic_ipi_wait(20))
+	if (!lapic_ipi_wait(100))
 		panic("Failed to deliver second STARTUP IPI to APIC %d",
 		    apic_id);