freebsd-skq/sys/dev/ichiic/ig4_var.h
grembo e7d021660e Protect smbus ioctls in ig4 driver using a shared lock.
Document locking semantics.

Differential Revision:	https://reviews.freebsd.org/D2744
Reviewed by:	jah, kib
Approved by:	kib
2015-06-25 07:52:51 +00:00

120 lines
4.1 KiB
C

/*
* Copyright (c) 2014 The DragonFly Project. All rights reserved.
*
* This code is derived from software contributed to The DragonFly Project
* by Matthew Dillon <dillon@backplane.com> and was subsequently ported
* to FreeBSD by Michael Gmelin <freebsd@grem.de>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name of The DragonFly Project nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific, prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef _BUS_SMBUS_INTELGEN4_IG4_VAR_H_
#define _BUS_SMBUS_INTELGEN4_IG4_VAR_H_
#include "bus_if.h"
#include "device_if.h"
#include "pci_if.h"
#include "smbus_if.h"
#define IG4_RBUFSIZE 128
#define IG4_RBUFMASK (IG4_RBUFSIZE - 1)
enum ig4_op { IG4_IDLE, IG4_READ, IG4_WRITE };
struct ig4iic_softc {
device_t dev;
struct intr_config_hook enum_hook;
device_t smb;
struct resource *regs_res;
int regs_rid;
struct resource *intr_res;
int intr_rid;
void *intr_handle;
int intr_type;
enum ig4_op op;
int cmd;
int rnext;
int rpos;
char rbuf[IG4_RBUFSIZE];
int error;
uint8_t last_slave;
int pci_attached : 1;
int use_10bit : 1;
int slave_valid : 1;
int read_started : 1;
int write_started : 1;
/*
* Locking semantics:
*
* Functions implementing the smbus interface that interact
* with the controller acquire an exclusive lock on call_lock
* to prevent interleaving of calls to the interface and a lock on
* io_lock right afterwards, to synchronize controller I/O activity.
*
* The interrupt handler can only read data while no ig4iic_smb_* call
* is in progress or while io_lock is dropped during mtx_sleep in
* wait_status and set_controller. It is safe to drop io_lock in those
* places, because the interrupt handler only accesses those registers:
*
* - IG4_REG_I2C_STA (I2C Status)
* - IG4_REG_DATA_CMD (Data Buffer and Command)
* - IG4_REG_CLR_INTR (Clear Interrupt)
*
* Locking outside of those places is required to make the content
* of rpos/rnext predictable (e.g. whenever data_read is called and in
* smb_transaction).
*/
struct sx call_lock;
struct mtx io_lock;
};
typedef struct ig4iic_softc ig4iic_softc_t;
/* Attach/Detach called from ig4iic_pci_*() */
int ig4iic_attach(ig4iic_softc_t *sc);
int ig4iic_detach(ig4iic_softc_t *sc);
/* SMBus methods */
extern smbus_callback_t ig4iic_smb_callback;
extern smbus_quick_t ig4iic_smb_quick;
extern smbus_sendb_t ig4iic_smb_sendb;
extern smbus_recvb_t ig4iic_smb_recvb;
extern smbus_writeb_t ig4iic_smb_writeb;
extern smbus_writew_t ig4iic_smb_writew;
extern smbus_readb_t ig4iic_smb_readb;
extern smbus_readw_t ig4iic_smb_readw;
extern smbus_pcall_t ig4iic_smb_pcall;
extern smbus_bwrite_t ig4iic_smb_bwrite;
extern smbus_bread_t ig4iic_smb_bread;
extern smbus_trans_t ig4iic_smb_trans;
#endif