[src/trunk]: src/sys/dev/spi Use mutex for lwp/interrupt coordination. using ...

[kardel <kardel%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/124270d7fb2e
branches:  trunk
changeset: 936797:124270d7fb2e
user:      kardel <kardel%NetBSD.org@localhost>
date:      Tue Aug 04 13:20:45 2020 +0000

description:
Use mutex for lwp/interrupt coordination. using splX() simply does not work
on multiprocessor systems.

fixes PR kern/55506

diffstat:

 sys/arch/arm/broadcom/bcm2835_spi.c |  17 ++++++++++-------
 sys/dev/spi/spi.c                   |   8 ++++----
 sys/dev/spi/spivar.h                |   4 ++--
 3 files changed, 16 insertions(+), 13 deletions(-)

diffs (136 lines):

diff -r 1dd01e4e42a5 -r 124270d7fb2e sys/arch/arm/broadcom/bcm2835_spi.c
--- a/sys/arch/arm/broadcom/bcm2835_spi.c       Tue Aug 04 06:23:46 2020 +0000
+++ b/sys/arch/arm/broadcom/bcm2835_spi.c       Tue Aug 04 13:20:45 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: bcm2835_spi.c,v 1.6 2019/08/13 17:03:10 tnn Exp $      */
+/*     $NetBSD: bcm2835_spi.c,v 1.7 2020/08/04 13:20:45 kardel Exp $   */
 
 /*
  * Copyright (c) 2012 Jonathan A. Kollasch
@@ -27,7 +27,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: bcm2835_spi.c,v 1.6 2019/08/13 17:03:10 tnn Exp $");
+__KERNEL_RCSID(0, "$NetBSD: bcm2835_spi.c,v 1.7 2020/08/04 13:20:45 kardel Exp $");
 
 #include <sys/param.h>
 #include <sys/device.h>
@@ -53,6 +53,7 @@
        bus_space_handle_t      sc_ioh;
        void                    *sc_intrh;
        struct spi_controller   sc_spi;
+       kmutex_t                sc_mutex;
        SIMPLEQ_HEAD(,spi_transfer) sc_q;
        struct spi_transfer     *sc_transfer;
        struct spi_chunk        *sc_wchunk;
@@ -131,6 +132,7 @@
        aprint_normal_dev(self, "interrupting on %s\n", intrstr);
 
        sc->sc_spi.sct_cookie = sc;
+       mutex_init(&sc->sc_mutex, MUTEX_DEFAULT, IPL_VM);
        sc->sc_spi.sct_configure = bcmspi_configure;
        sc->sc_spi.sct_transfer = bcmspi_transfer;
        sc->sc_spi.sct_nslaves = 3;
@@ -189,14 +191,13 @@
 bcmspi_transfer(void *cookie, struct spi_transfer *st)
 {
        struct bcmspi_softc * const sc = cookie;
-       int s;
 
-       s = splbio();
+       mutex_enter(&sc->sc_mutex);
        spi_transq_enqueue(&sc->sc_q, st);
        if (sc->sc_running == false) {
                bcmspi_start(sc);
        }
-       splx(s);
+       mutex_exit(&sc->sc_mutex);
        return 0;
 }
 
@@ -226,13 +227,13 @@
                if (!cold)
                        return;
 
-               int s = splbio();
                for (;;) {
+                       mutex_exit(&sc->sc_mutex);
                        bcmspi_intr(sc);
+                       mutex_enter(&sc->sc_mutex);
                        if (ISSET(st->st_flags, SPI_F_DONE))
                                break;
                }
-               splx(s);
        }
 
        sc->sc_running = false;
@@ -291,6 +292,7 @@
        struct spi_transfer *st;
        uint32_t cs;
 
+       mutex_enter(&sc->sc_mutex);
        cs = bus_space_read_4(sc->sc_iot, sc->sc_ioh, SPI_CS);
        if (ISSET(cs, SPI_CS_DONE)) {
                if (sc->sc_wchunk != NULL) {
@@ -314,5 +316,6 @@
        }
 
 end:
+       mutex_exit(&sc->sc_mutex);
        return ISSET(cs, SPI_CS_DONE|SPI_CS_RXR);
 }
diff -r 1dd01e4e42a5 -r 124270d7fb2e sys/dev/spi/spi.c
--- a/sys/dev/spi/spi.c Tue Aug 04 06:23:46 2020 +0000
+++ b/sys/dev/spi/spi.c Tue Aug 04 13:20:45 2020 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: spi.c,v 1.14 2020/06/11 02:39:30 thorpej Exp $ */
+/* $NetBSD: spi.c,v 1.15 2020/08/04 13:20:45 kardel Exp $ */
 
 /*-
  * Copyright (c) 2006 Urbana-Champaign Independent Media Center.
@@ -42,7 +42,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: spi.c,v 1.14 2020/06/11 02:39:30 thorpej Exp $");
+__KERNEL_RCSID(0, "$NetBSD: spi.c,v 1.15 2020/08/04 13:20:45 kardel Exp $");
 
 #include "locators.h"
 
@@ -287,7 +287,7 @@
        aprint_naive(": SPI bus\n");
        aprint_normal(": SPI bus\n");
 
-       mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_BIO);
+       mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_VM);
        cv_init(&sc->sc_cv, "spictl");
 
        sc->sc_controller = *sba->sba_controller;
@@ -463,7 +463,7 @@
 spi_transfer_init(struct spi_transfer *st)
 {
 
-       mutex_init(&st->st_lock, MUTEX_DEFAULT, IPL_BIO);
+       mutex_init(&st->st_lock, MUTEX_DEFAULT, IPL_VM);
        cv_init(&st->st_cv, "spixfr");
 
        st->st_flags = 0;
diff -r 1dd01e4e42a5 -r 124270d7fb2e sys/dev/spi/spivar.h
--- a/sys/dev/spi/spivar.h      Tue Aug 04 06:23:46 2020 +0000
+++ b/sys/dev/spi/spivar.h      Tue Aug 04 13:20:45 2020 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: spivar.h,v 1.9 2019/11/27 07:26:08 hkenken Exp $ */
+/* $NetBSD: spivar.h,v 1.10 2020/08/04 13:20:45 kardel Exp $ */
 
 /*-
  * Copyright (c) 2006 Urbana-Champaign Independent Media Center.
@@ -111,7 +111,7 @@
 struct spi_transfer {
        struct spi_chunk *st_chunks;            /* chained bufs */
        SIMPLEQ_ENTRY(spi_transfer) st_chain;   /* chain of submitted jobs */
-       int             st_flags;
+       volatile int    st_flags;
        int             st_errno;
        int             st_slave;
        void            *st_private;