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Replace the xxx_acquire()/xxx_release() rwlocks with mutexes. There are

Browse Source 
only RW_WRITERs for these, and no RW_READERs, so no need to incur the
extra overhead of allowing for both.  As discussed on tech-kern.

For piixpm and ichsmb, the acquire/release protocol needs to be used,
even if the request is I2C_F_POLL'd (or if the device supports only
polled mode).  Otherwise multiple requests can be running at the same
time, and they stomp on each other and create anomolous results.

Part 2 addresses my PR kern/45889

3 ACKs from releng
This commit is contained in:
pgoyette 2012-02-14 15:08:07 +00:00
parent 87c636f464
commit f76013d4aa
5 changed files with 35 additions and 37 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
sys/dev/pci/amdpm_smbus.c
View File

@ -1,4 +1,4 @@
/* $NetBSD: amdpm_smbus.c,v 1.17 2011/11/19 02:39:14 christos Exp $ */
/* $NetBSD: amdpm_smbus.c,v 1.18 2012/02/14 15:08:07 pgoyette Exp $ */
/*
* Copyright (c) 2005 Anil Gopinath (anil_public@yahoo.com)
@ -32,14 +32,14 @@
* AMD-8111 HyperTransport I/O Hub
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: amdpm_smbus.c,v 1.17 2011/11/19 02:39:14 christos Exp $");
__KERNEL_RCSID(0, "$NetBSD: amdpm_smbus.c,v 1.18 2012/02/14 15:08:07 pgoyette Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/device.h>
#include <sys/rnd.h>
#include <sys/rwlock.h>
#include <sys/mutex.h>
#include <dev/pci/pcireg.h>
#include <dev/pci/pcivar.h>
@ -83,7 +83,7 @@ amdpm_smbus_attach(struct amdpm_softc *sc)
sc->sc_i2c.ic_write_byte = NULL;
sc->sc_i2c.ic_exec = amdpm_smbus_exec;
rw_init(&sc->sc_rwlock);
mutex_init(&sc->sc_mutex, MUTEX_DEFAULT, IPL_NONE);
iba.iba_tag = &sc->sc_i2c;
(void)config_found_ia(&sc->sc_dev, "i2cbus", &iba, iicbus_print);
@ -94,7 +94,7 @@ amdpm_smbus_acquire_bus(void *cookie, int flags)
{
struct amdpm_softc *sc = cookie;
rw_enter(&sc->sc_rwlock, RW_WRITER);
mutex_enter(&sc->sc_mutex);
return 0;
}
@ -103,7 +103,7 @@ amdpm_smbus_release_bus(void *cookie, int flags)
{
struct amdpm_softc *sc = cookie;
rw_exit(&sc->sc_rwlock);
mutex_exit(&sc->sc_mutex);
}
static int

6
sys/dev/pci/amdpmvar.h
View File

@ -1,4 +1,4 @@
/* $NetBSD: amdpmvar.h,v 1.7 2011/11/19 22:51:23 tls Exp $ */
/* $NetBSD: amdpmvar.h,v 1.8 2012/02/14 15:08:07 pgoyette Exp $ */
/*-
* Copyright (c) 2002 The NetBSD Foundation, Inc.
@ -32,7 +32,7 @@
#ifndef _DEV_PCI_AMDPMVAR_H_
#define _DEV_PCI_AMDPMVAR_H_
#include <sys/rwlock.h>
#include <sys/mutex.h>
struct amdpm_softc {
struct device sc_dev;
@ -47,7 +47,7 @@ struct amdpm_softc {
i2c_addr_t sc_smbus_slaveaddr; /* address of smbus slave */
struct i2c_controller sc_i2c; /* i2c controller info */
krwlock_t sc_rwlock;
kmutex_t sc_mutex;
void *sc_ih;

18
sys/dev/pci/ichsmb.c
View File

@ -1,4 +1,4 @@
/* $NetBSD: ichsmb.c,v 1.26 2012/01/30 19:41:19 drochner Exp $ */
/* $NetBSD: ichsmb.c,v 1.27 2012/02/14 15:08:07 pgoyette Exp $ */
/* $OpenBSD: ichiic.c,v 1.18 2007/05/03 09:36:26 dlg Exp $ */
/*
@ -22,13 +22,13 @@
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: ichsmb.c,v 1.26 2012/01/30 19:41:19 drochner Exp $");
__KERNEL_RCSID(0, "$NetBSD: ichsmb.c,v 1.27 2012/02/14 15:08:07 pgoyette Exp $");
#include <sys/param.h>
#include <sys/device.h>
#include <sys/errno.h>
#include <sys/kernel.h>
#include <sys/rwlock.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/bus.h>
@ -59,7 +59,7 @@ struct ichsmb_softc {
int sc_poll;
struct i2c_controller sc_i2c_tag;
krwlock_t sc_i2c_rwlock;
kmutex_t sc_i2c_mutex;
struct {
i2c_op_t op;
void * buf;
@ -166,7 +166,7 @@ ichsmb_attach(device_t parent, device_t self, void *aux)
}
/* Attach I2C bus */
rw_init(&sc->sc_i2c_rwlock);
mutex_init(&sc->sc_i2c_mutex, MUTEX_DEFAULT, IPL_NONE);
sc->sc_i2c_tag.ic_cookie = sc;
sc->sc_i2c_tag.ic_acquire_bus = ichsmb_i2c_acquire_bus;
sc->sc_i2c_tag.ic_release_bus = ichsmb_i2c_release_bus;
@ -186,10 +186,10 @@ ichsmb_i2c_acquire_bus(void *cookie, int flags)
{
struct ichsmb_softc *sc = cookie;
if (cold || sc->sc_poll || (flags & I2C_F_POLL))
if (cold)
return 0;
rw_enter(&sc->sc_i2c_rwlock, RW_WRITER);
mutex_enter(&sc->sc_i2c_mutex);
return 0;
}
@ -198,10 +198,10 @@ ichsmb_i2c_release_bus(void *cookie, int flags)
{
struct ichsmb_softc *sc = cookie;
if (cold || sc->sc_poll || (flags & I2C_F_POLL))
if (cold)
return;
rw_exit(&sc->sc_i2c_rwlock);
mutex_exit(&sc->sc_i2c_mutex);
}
static int

14
sys/dev/pci/nfsmb.c
View File

@ -1,4 +1,4 @@
/* $NetBSD: nfsmb.c,v 1.22 2012/01/30 19:41:22 drochner Exp $ */
/* $NetBSD: nfsmb.c,v 1.23 2012/02/14 15:08:07 pgoyette Exp $ */
/*
* Copyright (c) 2007 KIYOHARA Takashi
* All rights reserved.
@ -26,13 +26,13 @@
*
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: nfsmb.c,v 1.22 2012/01/30 19:41:22 drochner Exp $");
__KERNEL_RCSID(0, "$NetBSD: nfsmb.c,v 1.23 2012/02/14 15:08:07 pgoyette Exp $");
#include <sys/param.h>
#include <sys/device.h>
#include <sys/errno.h>
#include <sys/kernel.h>
#include <sys/rwlock.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/bus.h>
@ -73,7 +73,7 @@ struct nfsmb_softc {
bus_space_handle_t sc_ioh;
struct i2c_controller sc_i2c; /* i2c controller info */
krwlock_t sc_rwlock;
kmutex_t sc_mutex;
};
@ -237,7 +237,7 @@ nfsmb_attach(device_t parent, device_t self, void *aux)
sc->sc_i2c.ic_write_byte = NULL;
sc->sc_i2c.ic_exec = nfsmb_exec;
rw_init(&sc->sc_rwlock);
mutex_init(&sc->sc_mutex, MUTEX_DEFAULT, IPL_NONE);
if (bus_space_map(sc->sc_iot, nfsmbcap->nfsmb_addr, NFORCE_SMBSIZE, 0,
&sc->sc_ioh) != 0) {
@ -261,7 +261,7 @@ nfsmb_acquire_bus(void *cookie, int flags)
{
struct nfsmb_softc *sc = cookie;
rw_enter(&sc->sc_rwlock, RW_WRITER);
mutex_enter(&sc->sc_mutex);
return 0;
}
@ -270,7 +270,7 @@ nfsmb_release_bus(void *cookie, int flags)
{
struct nfsmb_softc *sc = cookie;
rw_exit(&sc->sc_rwlock);
mutex_exit(&sc->sc_mutex);
}
static int

22
sys/dev/pci/piixpm.c
View File

@ -1,4 +1,4 @@
/* $NetBSD: piixpm.c,v 1.39 2012/01/30 19:41:22 drochner Exp $ */
/* $NetBSD: piixpm.c,v 1.40 2012/02/14 15:08:07 pgoyette Exp $ */
/* $OpenBSD: piixpm.c,v 1.20 2006/02/27 08:25:02 grange Exp $ */
/*
@ -22,13 +22,13 @@
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: piixpm.c,v 1.39 2012/01/30 19:41:22 drochner Exp $");
__KERNEL_RCSID(0, "$NetBSD: piixpm.c,v 1.40 2012/02/14 15:08:07 pgoyette Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/device.h>
#include <sys/kernel.h>
#include <sys/rwlock.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/bus.h>
@ -82,7 +82,7 @@ struct piixpm_softc {
pcireg_t sc_id;
struct i2c_controller sc_i2c_tag;
krwlock_t sc_i2c_rwlock;
kmutex_t sc_i2c_mutex;
struct {
i2c_op_t op;
void * buf;
@ -251,7 +251,7 @@ nopowermanagement:
attach_i2c:
/* Attach I2C bus */
rw_init(&sc->sc_i2c_rwlock);
mutex_init(&sc->sc_i2c_mutex, MUTEX_DEFAULT, IPL_NONE);
sc->sc_i2c_tag.ic_cookie = sc;
sc->sc_i2c_tag.ic_acquire_bus = piixpm_i2c_acquire_bus;
sc->sc_i2c_tag.ic_release_bus = piixpm_i2c_release_bus;
@ -331,6 +331,7 @@ piixpm_sb800_init(struct piixpm_softc *sc, struct pci_attach_args *pa)
aprint_error_dev(sc->sc_dev, "can't map smbus I/O space\n");
return EBUSY;
}
aprint_normal_dev(sc->sc_dev, "polling (SB800)\n");
sc->sc_poll = 1;
return 0;
@ -362,10 +363,9 @@ piixpm_i2c_acquire_bus(void *cookie, int flags)
{
struct piixpm_softc *sc = cookie;
if (cold || sc->sc_poll || (flags & I2C_F_POLL))
return (0);
if (!cold)
mutex_enter(&sc->sc_i2c_mutex);
rw_enter(&sc->sc_i2c_rwlock, RW_WRITER);
return 0;
}
@ -374,10 +374,8 @@ piixpm_i2c_release_bus(void *cookie, int flags)
{
struct piixpm_softc *sc = cookie;
if (cold || sc->sc_poll || (flags & I2C_F_POLL))
return;
rw_exit(&sc->sc_i2c_rwlock);
if (!cold)
mutex_exit(&sc->sc_i2c_mutex);
}
static int