[src/trunk]: src/sys/dev/pci Acquire SW semaphore in wm_get_swsm_semaphore

[ozaki-r <ozaki-r%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/277275144b6f
branches:  trunk
changeset: 330226:277275144b6f
user:      ozaki-r <ozaki-r%NetBSD.org@localhost>
date:      Mon Jun 30 06:09:44 2014 +0000

description:
Acquire SW semaphore in wm_get_swsm_semaphore

It is required to serialize device drivers running on different CPUs.
The basic instructions are same as the official Intel driver.

ok msaitoh@

diffstat:

 sys/dev/pci/if_wm.c |  25 +++++++++++++++++++++----
 1 files changed, 21 insertions(+), 4 deletions(-)

diffs (60 lines):

diff -r 33f03d0dcee3 -r 277275144b6f sys/dev/pci/if_wm.c
--- a/sys/dev/pci/if_wm.c       Mon Jun 30 05:52:24 2014 +0000
+++ b/sys/dev/pci/if_wm.c       Mon Jun 30 06:09:44 2014 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if_wm.c,v 1.270 2014/06/16 16:48:16 msaitoh Exp $      */
+/*     $NetBSD: if_wm.c,v 1.271 2014/06/30 06:09:44 ozaki-r Exp $      */
 
 /*
  * Copyright (c) 2001, 2002, 2003, 2004 Wasabi Systems, Inc.
@@ -76,7 +76,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_wm.c,v 1.270 2014/06/16 16:48:16 msaitoh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_wm.c,v 1.271 2014/06/30 06:09:44 ozaki-r Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -7569,6 +7569,23 @@
        int32_t timeout;
        uint32_t swsm;
 
+       /* Get the SW semaphore. */
+       timeout = 1000 + 1; /* XXX */
+       while (timeout) {
+               swsm = CSR_READ(sc, WMREG_SWSM);
+
+               if ((swsm & SWSM_SMBI) == 0)
+                       break;
+
+               delay(50);
+               timeout--;
+       }
+
+       if (timeout == 0) {
+               aprint_error_dev(sc->sc_dev, "could not acquire SWSM SMBI\n");
+               return 1;
+       }
+
        /* Get the FW semaphore. */
        timeout = 1000 + 1; /* XXX */
        while (timeout) {
@@ -7585,7 +7602,7 @@
        }
 
        if (timeout == 0) {
-               aprint_error_dev(sc->sc_dev, "could not acquire EEPROM GNT\n");
+               aprint_error_dev(sc->sc_dev, "could not acquire SWSM SWESMBI\n");
                /* Release semaphores */
                wm_put_swsm_semaphore(sc);
                return 1;
@@ -7599,7 +7616,7 @@
        uint32_t swsm;
 
        swsm = CSR_READ(sc, WMREG_SWSM);
-       swsm &= ~(SWSM_SWESMBI);
+       swsm &= ~(SWSM_SMBI | SWSM_SWESMBI);
        CSR_WRITE(sc, WMREG_SWSM, swsm);
 }