kernel-ark/drivers/scsi/NCR_D700.c
Adrian Bunk 8800727ae8 [SCSI] NCR_D700: fix a NULL dereference
The Coverity checker spotted this NULL dereference.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2006-03-12 09:45:43 -06:00

406 lines
10 KiB
C

/* -*- mode: c; c-basic-offset: 8 -*- */
/* NCR Dual 700 MCA SCSI Driver
*
* Copyright (C) 2001 by James.Bottomley@HansenPartnership.com
**-----------------------------------------------------------------------------
**
** This program is free software; you can redistribute it and/or modify
** it under the terms of the GNU General Public License as published by
** the Free Software Foundation; either version 2 of the License, or
** (at your option) any later version.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
** GNU General Public License for more details.
**
** You should have received a copy of the GNU General Public License
** along with this program; if not, write to the Free Software
** Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
**
**-----------------------------------------------------------------------------
*/
/* Notes:
*
* Most of the work is done in the chip specific module, 53c700.o
*
* TODO List:
*
* 1. Extract the SCSI ID from the voyager CMOS table (necessary to
* support multi-host environments.
*
* */
/* CHANGELOG
*
* Version 2.2
*
* Added mca_set_adapter_name().
*
* Version 2.1
*
* Modularise the driver into a Board piece (this file) and a chip
* piece 53c700.[ch] and 53c700.scr, added module options. You can
* now specify the scsi id by the parameters
*
* NCR_D700=slot:<n> [siop:<n>] id:<n> ....
*
* They need to be comma separated if compiled into the kernel
*
* Version 2.0
*
* Initial implementation of TCQ (Tag Command Queueing). TCQ is full
* featured and uses the clock algorithm to keep track of outstanding
* tags and guard against individual tag starvation. Also fixed a bug
* in all of the 1.x versions where the D700_data_residue() function
* was returning results off by 32 bytes (and thus causing the same 32
* bytes to be written twice corrupting the data block). It turns out
* the 53c700 only has a 6 bit DBC and DFIFO registers not 7 bit ones
* like the 53c710 (The 710 is the only data manual still available,
* which I'd been using to program the 700).
*
* Version 1.2
*
* Much improved message handling engine
*
* Version 1.1
*
* Add code to handle selection reasonably correctly. By the time we
* get the selection interrupt, we've already responded, but drop off the
* bus and hope the selector will go away.
*
* Version 1.0:
*
* Initial release. Fully functional except for procfs and tag
* command queueing. Has only been tested on cards with 53c700-66
* chips and only single ended. Features are
*
* 1. Synchronous data transfers to offset 8 (limit of 700-66) and
* 100ns (10MHz) limit of SCSI-2
*
* 2. Disconnection and reselection
*
* Testing:
*
* I've only really tested this with the 700-66 chip, but have done
* soak tests in multi-device environments to verify that
* disconnections and reselections are being processed correctly.
* */
#define NCR_D700_VERSION "2.2"
#include <linux/blkdev.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mca.h>
#include <linux/interrupt.h>
#include <asm/io.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_transport.h>
#include <scsi/scsi_transport_spi.h>
#include "53c700.h"
#include "NCR_D700.h"
static char *NCR_D700; /* command line from insmod */
MODULE_AUTHOR("James Bottomley");
MODULE_DESCRIPTION("NCR Dual700 SCSI Driver");
MODULE_LICENSE("GPL");
module_param(NCR_D700, charp, 0);
static __u8 __initdata id_array[2*(MCA_MAX_SLOT_NR + 1)] =
{ [0 ... 2*(MCA_MAX_SLOT_NR + 1)-1] = 7 };
#ifdef MODULE
#define ARG_SEP ' '
#else
#define ARG_SEP ','
#endif
static int __init
param_setup(char *string)
{
char *pos = string, *next;
int slot = -1, siop = -1;
while(pos != NULL && (next = strchr(pos, ':')) != NULL) {
int val = (int)simple_strtoul(++next, NULL, 0);
if(!strncmp(pos, "slot:", 5))
slot = val;
else if(!strncmp(pos, "siop:", 5))
siop = val;
else if(!strncmp(pos, "id:", 3)) {
if(slot == -1) {
printk(KERN_WARNING "NCR D700: Must specify slot for id parameter\n");
} else if(slot > MCA_MAX_SLOT_NR) {
printk(KERN_WARNING "NCR D700: Illegal slot %d for id %d\n", slot, val);
} else {
if(siop != 0 && siop != 1) {
id_array[slot*2] = val;
id_array[slot*2 + 1] =val;
} else {
id_array[slot*2 + siop] = val;
}
}
}
if((pos = strchr(pos, ARG_SEP)) != NULL)
pos++;
}
return 1;
}
/* Host template. The 53c700 routine NCR_700_detect will
* fill in all of the missing routines */
static struct scsi_host_template NCR_D700_driver_template = {
.module = THIS_MODULE,
.name = "NCR Dual 700 MCA",
.proc_name = "NCR_D700",
.this_id = 7,
};
/* We needs this helper because we have two hosts per struct device */
struct NCR_D700_private {
struct device *dev;
struct Scsi_Host *hosts[2];
char name[30];
char pad;
};
static int
NCR_D700_probe_one(struct NCR_D700_private *p, int siop, int irq,
int slot, u32 region, int differential)
{
struct NCR_700_Host_Parameters *hostdata;
struct Scsi_Host *host;
int ret;
hostdata = kmalloc(sizeof(*hostdata), GFP_KERNEL);
if (!hostdata) {
printk(KERN_ERR "NCR D700: SIOP%d: Failed to allocate host"
"data, detatching\n", siop);
return -ENOMEM;
}
memset(hostdata, 0, sizeof(*hostdata));
if (!request_region(region, 64, "NCR_D700")) {
printk(KERN_ERR "NCR D700: Failed to reserve IO region 0x%x\n",
region);
ret = -ENODEV;
goto region_failed;
}
/* Fill in the three required pieces of hostdata */
hostdata->base = ioport_map(region, 64);
hostdata->differential = (((1<<siop) & differential) != 0);
hostdata->clock = NCR_D700_CLOCK_MHZ;
/* and register the siop */
host = NCR_700_detect(&NCR_D700_driver_template, hostdata, p->dev);
if (!host) {
ret = -ENOMEM;
goto detect_failed;
}
p->hosts[siop] = host;
/* FIXME: read this from SUS */
host->this_id = id_array[slot * 2 + siop];
host->irq = irq;
host->base = region;
scsi_scan_host(host);
return 0;
detect_failed:
release_region(region, 64);
region_failed:
kfree(hostdata);
return ret;
}
static int
NCR_D700_intr(int irq, void *data, struct pt_regs *regs)
{
struct NCR_D700_private *p = (struct NCR_D700_private *)data;
int i, found = 0;
for (i = 0; i < 2; i++)
if (p->hosts[i] &&
NCR_700_intr(irq, p->hosts[i], regs) == IRQ_HANDLED)
found++;
return found ? IRQ_HANDLED : IRQ_NONE;
}
/* Detect a D700 card. Note, because of the setup --- the chips are
* essentially connectecd to the MCA bus independently, it is easier
* to set them up as two separate host adapters, rather than one
* adapter with two channels */
static int
NCR_D700_probe(struct device *dev)
{
struct NCR_D700_private *p;
int differential;
static int banner = 1;
struct mca_device *mca_dev = to_mca_device(dev);
int slot = mca_dev->slot;
int found = 0;
int irq, i;
int pos3j, pos3k, pos3a, pos3b, pos4;
__u32 base_addr, offset_addr;
/* enable board interrupt */
pos4 = mca_device_read_pos(mca_dev, 4);
pos4 |= 0x4;
mca_device_write_pos(mca_dev, 4, pos4);
mca_device_write_pos(mca_dev, 6, 9);
pos3j = mca_device_read_pos(mca_dev, 3);
mca_device_write_pos(mca_dev, 6, 10);
pos3k = mca_device_read_pos(mca_dev, 3);
mca_device_write_pos(mca_dev, 6, 0);
pos3a = mca_device_read_pos(mca_dev, 3);
mca_device_write_pos(mca_dev, 6, 1);
pos3b = mca_device_read_pos(mca_dev, 3);
base_addr = ((pos3j << 8) | pos3k) & 0xfffffff0;
offset_addr = ((pos3a << 8) | pos3b) & 0xffffff70;
irq = (pos4 & 0x3) + 11;
if(irq >= 13)
irq++;
if(banner) {
printk(KERN_NOTICE "NCR D700: Driver Version " NCR_D700_VERSION "\n"
"NCR D700: Copyright (c) 2001 by James.Bottomley@HansenPartnership.com\n"
"NCR D700:\n");
banner = 0;
}
/* now do the bus related transforms */
irq = mca_device_transform_irq(mca_dev, irq);
base_addr = mca_device_transform_ioport(mca_dev, base_addr);
offset_addr = mca_device_transform_ioport(mca_dev, offset_addr);
printk(KERN_NOTICE "NCR D700: found in slot %d irq = %d I/O base = 0x%x\n", slot, irq, offset_addr);
/*outb(BOARD_RESET, base_addr);*/
/* clear any pending interrupts */
(void)inb(base_addr + 0x08);
/* get modctl, used later for setting diff bits */
switch(differential = (inb(base_addr + 0x08) >> 6)) {
case 0x00:
/* only SIOP1 differential */
differential = 0x02;
break;
case 0x01:
/* Both SIOPs differential */
differential = 0x03;
break;
case 0x03:
/* No SIOPs differential */
differential = 0x00;
break;
default:
printk(KERN_ERR "D700: UNEXPECTED DIFFERENTIAL RESULT 0x%02x\n",
differential);
differential = 0x00;
break;
}
p = kmalloc(sizeof(*p), GFP_KERNEL);
if (!p)
return -ENOMEM;
memset(p, '\0', sizeof(*p));
p->dev = dev;
snprintf(p->name, sizeof(p->name), "D700(%s)", dev->bus_id);
if (request_irq(irq, NCR_D700_intr, SA_SHIRQ, p->name, p)) {
printk(KERN_ERR "D700: request_irq failed\n");
kfree(p);
return -EBUSY;
}
/* plumb in both 700 chips */
for (i = 0; i < 2; i++) {
int err;
if ((err = NCR_D700_probe_one(p, i, slot, irq,
offset_addr + (0x80 * i),
differential)) != 0)
printk("D700: SIOP%d: probe failed, error = %d\n",
i, err);
else
found++;
}
if (!found) {
kfree(p);
return -ENODEV;
}
mca_device_set_claim(mca_dev, 1);
mca_device_set_name(mca_dev, "NCR_D700");
dev_set_drvdata(dev, p);
return 0;
}
static void
NCR_D700_remove_one(struct Scsi_Host *host)
{
scsi_remove_host(host);
NCR_700_release(host);
kfree((struct NCR_700_Host_Parameters *)host->hostdata[0]);
free_irq(host->irq, host);
release_region(host->base, 64);
}
static int
NCR_D700_remove(struct device *dev)
{
struct NCR_D700_private *p = dev_get_drvdata(dev);
int i;
for (i = 0; i < 2; i++)
NCR_D700_remove_one(p->hosts[i]);
kfree(p);
return 0;
}
static short NCR_D700_id_table[] = { NCR_D700_MCA_ID, 0 };
static struct mca_driver NCR_D700_driver = {
.id_table = NCR_D700_id_table,
.driver = {
.name = "NCR_D700",
.bus = &mca_bus_type,
.probe = NCR_D700_probe,
.remove = NCR_D700_remove,
},
};
static int __init NCR_D700_init(void)
{
#ifdef MODULE
if (NCR_D700)
param_setup(NCR_D700);
#endif
return mca_register_driver(&NCR_D700_driver);
}
static void __exit NCR_D700_exit(void)
{
mca_unregister_driver(&NCR_D700_driver);
}
module_init(NCR_D700_init);
module_exit(NCR_D700_exit);
__setup("NCR_D700=", param_setup);