linux/drivers/scsi/fd_mcs.c

1367 lines
40 KiB
C
Raw Normal View History

/* fd_mcs.c -- Future Domain MCS 600/700 (or IBM OEM) driver
*
* FutureDomain MCS-600/700 v0.2 03/11/1998 by ZP Gu (zpg@castle.net)
*
* This driver is cloned from fdomain.* to specifically support
* the Future Domain MCS 600/700 MCA SCSI adapters. Some PS/2s
* also equipped with IBM Fast SCSI Adapter/A which is an OEM
* of MCS 700.
*
* This driver also supports Reply SB16/SCSI card (the SCSI part).
*
* What makes this driver different is that this driver is MCA only
* and it supports multiple adapters in the same system, IRQ
* sharing, some driver statistics, and maps highest SCSI id to sda.
* All cards are auto-detected.
*
* Assumptions: TMC-1800/18C50/18C30, BIOS >= 3.4
*
* LILO command-line options:
* fd_mcs=<FIFO_COUNT>[,<FIFO_SIZE>]
*
* ********************************************************
* Please see Copyrights/Comments in fdomain.* for credits.
* Following is from fdomain.c for acknowledgement:
*
* Created: Sun May 3 18:53:19 1992 by faith@cs.unc.edu
* Revised: Wed Oct 2 11:10:55 1996 by r.faith@ieee.org
* Author: Rickard E. Faith, faith@cs.unc.edu
* Copyright 1992, 1993, 1994, 1995, 1996 Rickard E. Faith
*
* $Id: fdomain.c,v 5.45 1996/10/02 15:13:06 root Exp $
* 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, 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 ON USER DEFINABLE OPTIONS:
DEBUG: This turns on the printing of various debug information.
ENABLE_PARITY: This turns on SCSI parity checking. With the current
driver, all attached devices must support SCSI parity. If none of your
devices support parity, then you can probably get the driver to work by
turning this option off. I have no way of testing this, however, and it
would appear that no one ever uses this option.
FIFO_COUNT: The host adapter has an 8K cache (host adapters based on the
18C30 chip have a 2k cache). When this many 512 byte blocks are filled by
the SCSI device, an interrupt will be raised. Therefore, this could be as
low as 0, or as high as 16. Note, however, that values which are too high
or too low seem to prevent any interrupts from occurring, and thereby lock
up the machine. I have found that 2 is a good number, but throughput may
be increased by changing this value to values which are close to 2.
Please let me know if you try any different values.
[*****Now a runtime option*****]
RESELECTION: This is no longer an option, since I gave up trying to
implement it in version 4.x of this driver. It did not improve
performance at all and made the driver unstable (because I never found one
of the two race conditions which were introduced by the multiple
outstanding command code). The instability seems a very high price to pay
just so that you don't have to wait for the tape to rewind. If you want
this feature implemented, send me patches. I'll be happy to send a copy
of my (broken) driver to anyone who would like to see a copy.
**************************************************************************/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/blkdev.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/ioport.h>
#include <linux/proc_fs.h>
#include <linux/delay.h>
#include <linux/mca.h>
#include <linux/spinlock.h>
#include <scsi/scsicam.h>
#include <linux/mca-legacy.h>
#include <asm/io.h>
#include <asm/system.h>
#include "scsi.h"
#include <scsi/scsi_host.h>
#define DRIVER_VERSION "v0.2 by ZP Gu<zpg@castle.net>"
/* START OF USER DEFINABLE OPTIONS */
#define DEBUG 0 /* Enable debugging output */
#define ENABLE_PARITY 1 /* Enable SCSI Parity */
/* END OF USER DEFINABLE OPTIONS */
#if DEBUG
#define EVERY_ACCESS 0 /* Write a line on every scsi access */
#define ERRORS_ONLY 1 /* Only write a line if there is an error */
#define DEBUG_MESSAGES 1 /* Debug MESSAGE IN phase */
#define DEBUG_ABORT 1 /* Debug abort() routine */
#define DEBUG_RESET 1 /* Debug reset() routine */
#define DEBUG_RACE 1 /* Debug interrupt-driven race condition */
#else
#define EVERY_ACCESS 0 /* LEAVE THESE ALONE--CHANGE THE ONES ABOVE */
#define ERRORS_ONLY 0
#define DEBUG_MESSAGES 0
#define DEBUG_ABORT 0
#define DEBUG_RESET 0
#define DEBUG_RACE 0
#endif
/* Errors are reported on the line, so we don't need to report them again */
#if EVERY_ACCESS
#undef ERRORS_ONLY
#define ERRORS_ONLY 0
#endif
#if ENABLE_PARITY
#define PARITY_MASK 0x08
#else
#define PARITY_MASK 0x00
#endif
enum chip_type {
unknown = 0x00,
tmc1800 = 0x01,
tmc18c50 = 0x02,
tmc18c30 = 0x03,
};
enum {
in_arbitration = 0x02,
in_selection = 0x04,
in_other = 0x08,
disconnect = 0x10,
aborted = 0x20,
sent_ident = 0x40,
};
enum in_port_type {
Read_SCSI_Data = 0,
SCSI_Status = 1,
TMC_Status = 2,
FIFO_Status = 3, /* tmc18c50/tmc18c30 only */
Interrupt_Cond = 4, /* tmc18c50/tmc18c30 only */
LSB_ID_Code = 5,
MSB_ID_Code = 6,
Read_Loopback = 7,
SCSI_Data_NoACK = 8,
Interrupt_Status = 9,
Configuration1 = 10,
Configuration2 = 11, /* tmc18c50/tmc18c30 only */
Read_FIFO = 12,
FIFO_Data_Count = 14
};
enum out_port_type {
Write_SCSI_Data = 0,
SCSI_Cntl = 1,
Interrupt_Cntl = 2,
SCSI_Mode_Cntl = 3,
TMC_Cntl = 4,
Memory_Cntl = 5, /* tmc18c50/tmc18c30 only */
Write_Loopback = 7,
IO_Control = 11, /* tmc18c30 only */
Write_FIFO = 12
};
struct fd_hostdata {
unsigned long _bios_base;
int _bios_major;
int _bios_minor;
volatile int _in_command;
Scsi_Cmnd *_current_SC;
enum chip_type _chip;
int _adapter_mask;
int _fifo_count; /* Number of 512 byte blocks before INTR */
char _adapter_name[64];
#if DEBUG_RACE
volatile int _in_interrupt_flag;
#endif
int _SCSI_Mode_Cntl_port;
int _FIFO_Data_Count_port;
int _Interrupt_Cntl_port;
int _Interrupt_Status_port;
int _Interrupt_Cond_port;
int _Read_FIFO_port;
int _Read_SCSI_Data_port;
int _SCSI_Cntl_port;
int _SCSI_Data_NoACK_port;
int _SCSI_Status_port;
int _TMC_Cntl_port;
int _TMC_Status_port;
int _Write_FIFO_port;
int _Write_SCSI_Data_port;
int _FIFO_Size; /* = 0x2000; 8k FIFO for
pre-tmc18c30 chips */
/* simple stats */
int _Bytes_Read;
int _Bytes_Written;
int _INTR_Processed;
};
#define FD_MAX_HOSTS 3 /* enough? */
#define HOSTDATA(shpnt) ((struct fd_hostdata *) shpnt->hostdata)
#define bios_base (HOSTDATA(shpnt)->_bios_base)
#define bios_major (HOSTDATA(shpnt)->_bios_major)
#define bios_minor (HOSTDATA(shpnt)->_bios_minor)
#define in_command (HOSTDATA(shpnt)->_in_command)
#define current_SC (HOSTDATA(shpnt)->_current_SC)
#define chip (HOSTDATA(shpnt)->_chip)
#define adapter_mask (HOSTDATA(shpnt)->_adapter_mask)
#define FIFO_COUNT (HOSTDATA(shpnt)->_fifo_count)
#define adapter_name (HOSTDATA(shpnt)->_adapter_name)
#if DEBUG_RACE
#define in_interrupt_flag (HOSTDATA(shpnt)->_in_interrupt_flag)
#endif
#define SCSI_Mode_Cntl_port (HOSTDATA(shpnt)->_SCSI_Mode_Cntl_port)
#define FIFO_Data_Count_port (HOSTDATA(shpnt)->_FIFO_Data_Count_port)
#define Interrupt_Cntl_port (HOSTDATA(shpnt)->_Interrupt_Cntl_port)
#define Interrupt_Status_port (HOSTDATA(shpnt)->_Interrupt_Status_port)
#define Interrupt_Cond_port (HOSTDATA(shpnt)->_Interrupt_Cond_port)
#define Read_FIFO_port (HOSTDATA(shpnt)->_Read_FIFO_port)
#define Read_SCSI_Data_port (HOSTDATA(shpnt)->_Read_SCSI_Data_port)
#define SCSI_Cntl_port (HOSTDATA(shpnt)->_SCSI_Cntl_port)
#define SCSI_Data_NoACK_port (HOSTDATA(shpnt)->_SCSI_Data_NoACK_port)
#define SCSI_Status_port (HOSTDATA(shpnt)->_SCSI_Status_port)
#define TMC_Cntl_port (HOSTDATA(shpnt)->_TMC_Cntl_port)
#define TMC_Status_port (HOSTDATA(shpnt)->_TMC_Status_port)
#define Write_FIFO_port (HOSTDATA(shpnt)->_Write_FIFO_port)
#define Write_SCSI_Data_port (HOSTDATA(shpnt)->_Write_SCSI_Data_port)
#define FIFO_Size (HOSTDATA(shpnt)->_FIFO_Size)
#define Bytes_Read (HOSTDATA(shpnt)->_Bytes_Read)
#define Bytes_Written (HOSTDATA(shpnt)->_Bytes_Written)
#define INTR_Processed (HOSTDATA(shpnt)->_INTR_Processed)
struct fd_mcs_adapters_struct {
char *name;
int id;
enum chip_type fd_chip;
int fifo_size;
int fifo_count;
};
#define REPLY_ID 0x5137
static struct fd_mcs_adapters_struct fd_mcs_adapters[] = {
{"Future Domain SCSI Adapter MCS-700(18C50)",
0x60e9,
tmc18c50,
0x2000,
4},
{"Future Domain SCSI Adapter MCS-600/700(TMC-1800)",
0x6127,
tmc1800,
0x2000,
4},
{"Reply Sound Blaster/SCSI Adapter",
REPLY_ID,
tmc18c30,
0x800,
2},
};
#define FD_BRDS ARRAY_SIZE(fd_mcs_adapters)
IRQ: Maintain regs pointer globally rather than passing to IRQ handlers Maintain a per-CPU global "struct pt_regs *" variable which can be used instead of passing regs around manually through all ~1800 interrupt handlers in the Linux kernel. The regs pointer is used in few places, but it potentially costs both stack space and code to pass it around. On the FRV arch, removing the regs parameter from all the genirq function results in a 20% speed up of the IRQ exit path (ie: from leaving timer_interrupt() to leaving do_IRQ()). Where appropriate, an arch may override the generic storage facility and do something different with the variable. On FRV, for instance, the address is maintained in GR28 at all times inside the kernel as part of general exception handling. Having looked over the code, it appears that the parameter may be handed down through up to twenty or so layers of functions. Consider a USB character device attached to a USB hub, attached to a USB controller that posts its interrupts through a cascaded auxiliary interrupt controller. A character device driver may want to pass regs to the sysrq handler through the input layer which adds another few layers of parameter passing. I've build this code with allyesconfig for x86_64 and i386. I've runtested the main part of the code on FRV and i386, though I can't test most of the drivers. I've also done partial conversion for powerpc and MIPS - these at least compile with minimal configurations. This will affect all archs. Mostly the changes should be relatively easy. Take do_IRQ(), store the regs pointer at the beginning, saving the old one: struct pt_regs *old_regs = set_irq_regs(regs); And put the old one back at the end: set_irq_regs(old_regs); Don't pass regs through to generic_handle_irq() or __do_IRQ(). In timer_interrupt(), this sort of change will be necessary: - update_process_times(user_mode(regs)); - profile_tick(CPU_PROFILING, regs); + update_process_times(user_mode(get_irq_regs())); + profile_tick(CPU_PROFILING); I'd like to move update_process_times()'s use of get_irq_regs() into itself, except that i386, alone of the archs, uses something other than user_mode(). Some notes on the interrupt handling in the drivers: (*) input_dev() is now gone entirely. The regs pointer is no longer stored in the input_dev struct. (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does something different depending on whether it's been supplied with a regs pointer or not. (*) Various IRQ handler function pointers have been moved to type irq_handler_t. Signed-Off-By: David Howells <dhowells@redhat.com> (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 13:55:46 +00:00
static irqreturn_t fd_mcs_intr(int irq, void *dev_id);
static unsigned long addresses[] = { 0xc8000, 0xca000, 0xce000, 0xde000 };
static unsigned short ports[] = { 0x140, 0x150, 0x160, 0x170 };
static unsigned short interrupts[] = { 3, 5, 10, 11, 12, 14, 15, 0 };
/* host information */
static int found = 0;
static struct Scsi_Host *hosts[FD_MAX_HOSTS + 1] = { NULL };
static int user_fifo_count = 0;
static int user_fifo_size = 0;
#ifndef MODULE
static int __init fd_mcs_setup(char *str)
{
static int done_setup = 0;
int ints[3];
get_options(str, 3, ints);
if (done_setup++ || ints[0] < 1 || ints[0] > 2 || ints[1] < 1 || ints[1] > 16) {
printk("fd_mcs: usage: fd_mcs=FIFO_COUNT, FIFO_SIZE\n");
return 0;
}
user_fifo_count = ints[0] >= 1 ? ints[1] : 0;
user_fifo_size = ints[0] >= 2 ? ints[2] : 0;
return 1;
}
__setup("fd_mcs=", fd_mcs_setup);
#endif /* !MODULE */
static void print_banner(struct Scsi_Host *shpnt)
{
printk("scsi%d <fd_mcs>: ", shpnt->host_no);
if (bios_base) {
printk("BIOS at 0x%lX", bios_base);
} else {
printk("No BIOS");
}
printk(", HostID %d, %s Chip, IRQ %d, IO 0x%lX\n", shpnt->this_id, chip == tmc18c50 ? "TMC-18C50" : (chip == tmc18c30 ? "TMC-18C30" : (chip == tmc1800 ? "TMC-1800" : "Unknown")), shpnt->irq, shpnt->io_port);
}
static void do_pause(unsigned amount)
{ /* Pause for amount*10 milliseconds */
do {
mdelay(10);
} while (--amount);
}
static void fd_mcs_make_bus_idle(struct Scsi_Host *shpnt)
{
outb(0, SCSI_Cntl_port);
outb(0, SCSI_Mode_Cntl_port);
if (chip == tmc18c50 || chip == tmc18c30)
outb(0x21 | PARITY_MASK, TMC_Cntl_port); /* Clear forced intr. */
else
outb(0x01 | PARITY_MASK, TMC_Cntl_port);
}
static int fd_mcs_detect(struct scsi_host_template * tpnt)
{
int loop;
struct Scsi_Host *shpnt;
/* get id, port, bios, irq */
int slot;
u_char pos2, pos3, pos4;
int id, port, irq;
unsigned long bios;
/* if not MCA machine, return */
if (!MCA_bus)
return 0;
/* changeable? */
id = 7;
for (loop = 0; loop < FD_BRDS; loop++) {
slot = 0;
while (MCA_NOTFOUND != (slot = mca_find_adapter(fd_mcs_adapters[loop].id, slot))) {
/* if we get this far, an adapter has been detected and is
enabled */
printk(KERN_INFO "scsi <fd_mcs>: %s at slot %d\n", fd_mcs_adapters[loop].name, slot + 1);
pos2 = mca_read_stored_pos(slot, 2);
pos3 = mca_read_stored_pos(slot, 3);
pos4 = mca_read_stored_pos(slot, 4);
/* ready for next probe */
slot++;
if (fd_mcs_adapters[loop].id == REPLY_ID) { /* reply card */
static int reply_irq[] = { 10, 11, 14, 15 };
bios = 0; /* no bios */
if (pos2 & 0x2)
port = ports[pos4 & 0x3];
else
continue;
/* can't really disable it, same as irq=10 */
irq = reply_irq[((pos4 >> 2) & 0x1) + 2 * ((pos4 >> 4) & 0x1)];
} else {
bios = addresses[pos2 >> 6];
port = ports[(pos2 >> 4) & 0x03];
irq = interrupts[(pos2 >> 1) & 0x07];
}
if (irq) {
/* claim the slot */
mca_set_adapter_name(slot - 1, fd_mcs_adapters[loop].name);
/* check irq/region */
if (request_irq(irq, fd_mcs_intr, IRQF_SHARED, "fd_mcs", hosts)) {
printk(KERN_ERR "fd_mcs: interrupt is not available, skipping...\n");
continue;
}
/* request I/O region */
if (request_region(port, 0x10, "fd_mcs")) {
printk(KERN_ERR "fd_mcs: I/O region is already in use, skipping...\n");
continue;
}
/* register */
if (!(shpnt = scsi_register(tpnt, sizeof(struct fd_hostdata)))) {
printk(KERN_ERR "fd_mcs: scsi_register() failed\n");
release_region(port, 0x10);
free_irq(irq, hosts);
continue;
}
/* save name */
strcpy(adapter_name, fd_mcs_adapters[loop].name);
/* chip/fifo */
chip = fd_mcs_adapters[loop].fd_chip;
/* use boot time value if available */
FIFO_COUNT = user_fifo_count ? user_fifo_count : fd_mcs_adapters[loop].fifo_count;
FIFO_Size = user_fifo_size ? user_fifo_size : fd_mcs_adapters[loop].fifo_size;
/* FIXME: Do we need to keep this bit of code inside NOT_USED around at all? */
#ifdef NOT_USED
/* *************************************************** */
/* Try to toggle 32-bit mode. This only
works on an 18c30 chip. (User reports
say this works, so we should switch to
it in the near future.) */
outb(0x80, port + IO_Control);
if ((inb(port + Configuration2) & 0x80) == 0x80) {
outb(0x00, port + IO_Control);
if ((inb(port + Configuration2) & 0x80) == 0x00) {
chip = tmc18c30;
FIFO_Size = 0x800; /* 2k FIFO */
printk("FIRST: chip=%s, fifo_size=0x%x\n", (chip == tmc18c30) ? "tmc18c30" : "tmc18c50", FIFO_Size);
}
}
/* That should have worked, but appears to
have problems. Let's assume it is an
18c30 if the RAM is disabled. */
if (inb(port + Configuration2) & 0x02) {
chip = tmc18c30;
FIFO_Size = 0x800; /* 2k FIFO */
printk("SECOND: chip=%s, fifo_size=0x%x\n", (chip == tmc18c30) ? "tmc18c30" : "tmc18c50", FIFO_Size);
}
/* *************************************************** */
#endif
/* IBM/ANSI scsi scan ordering */
/* Stick this back in when the scsi.c changes are there */
shpnt->reverse_ordering = 1;
/* saving info */
hosts[found++] = shpnt;
shpnt->this_id = id;
shpnt->irq = irq;
shpnt->io_port = port;
shpnt->n_io_port = 0x10;
/* save */
bios_base = bios;
adapter_mask = (1 << id);
/* save more */
SCSI_Mode_Cntl_port = port + SCSI_Mode_Cntl;
FIFO_Data_Count_port = port + FIFO_Data_Count;
Interrupt_Cntl_port = port + Interrupt_Cntl;
Interrupt_Status_port = port + Interrupt_Status;
Interrupt_Cond_port = port + Interrupt_Cond;
Read_FIFO_port = port + Read_FIFO;
Read_SCSI_Data_port = port + Read_SCSI_Data;
SCSI_Cntl_port = port + SCSI_Cntl;
SCSI_Data_NoACK_port = port + SCSI_Data_NoACK;
SCSI_Status_port = port + SCSI_Status;
TMC_Cntl_port = port + TMC_Cntl;
TMC_Status_port = port + TMC_Status;
Write_FIFO_port = port + Write_FIFO;
Write_SCSI_Data_port = port + Write_SCSI_Data;
Bytes_Read = 0;
Bytes_Written = 0;
INTR_Processed = 0;
/* say something */
print_banner(shpnt);
/* reset */
outb(1, SCSI_Cntl_port);
do_pause(2);
outb(0, SCSI_Cntl_port);
do_pause(115);
outb(0, SCSI_Mode_Cntl_port);
outb(PARITY_MASK, TMC_Cntl_port);
/* done reset */
}
}
if (found == FD_MAX_HOSTS) {
printk("fd_mcs: detecting reached max=%d host adapters.\n", FD_MAX_HOSTS);
break;
}
}
return found;
}
static const char *fd_mcs_info(struct Scsi_Host *shpnt)
{
return adapter_name;
}
static int TOTAL_INTR = 0;
/*
* inout : decides on the direction of the dataflow and the meaning of the
* variables
* buffer: If inout==FALSE data is being written to it else read from it
* *start: If inout==FALSE start of the valid data in the buffer
* offset: If inout==FALSE offset from the beginning of the imaginary file
* from which we start writing into the buffer
* length: If inout==FALSE max number of bytes to be written into the buffer
* else number of bytes in the buffer
*/
static int fd_mcs_proc_info(struct Scsi_Host *shpnt, char *buffer, char **start, off_t offset, int length, int inout)
{
int len = 0;
if (inout)
return (-ENOSYS);
*start = buffer + offset;
len += sprintf(buffer + len, "Future Domain MCS-600/700 Driver %s\n", DRIVER_VERSION);
len += sprintf(buffer + len, "HOST #%d: %s\n", shpnt->host_no, adapter_name);
len += sprintf(buffer + len, "FIFO Size=0x%x, FIFO Count=%d\n", FIFO_Size, FIFO_COUNT);
len += sprintf(buffer + len, "DriverCalls=%d, Interrupts=%d, BytesRead=%d, BytesWrite=%d\n\n", TOTAL_INTR, INTR_Processed, Bytes_Read, Bytes_Written);
if ((len -= offset) <= 0)
return 0;
if (len > length)
len = length;
return len;
}
static int fd_mcs_select(struct Scsi_Host *shpnt, int target)
{
int status;
unsigned long timeout;
outb(0x82, SCSI_Cntl_port); /* Bus Enable + Select */
outb(adapter_mask | (1 << target), SCSI_Data_NoACK_port);
/* Stop arbitration and enable parity */
outb(PARITY_MASK, TMC_Cntl_port);
timeout = 350; /* 350mS -- because of timeouts
(was 250mS) */
do {
status = inb(SCSI_Status_port); /* Read adapter status */
if (status & 1) { /* Busy asserted */
/* Enable SCSI Bus (on error, should make bus idle with 0) */
outb(0x80, SCSI_Cntl_port);
return 0;
}
udelay(1000); /* wait one msec */
} while (--timeout);
/* Make bus idle */
fd_mcs_make_bus_idle(shpnt);
#if EVERY_ACCESS
if (!target)
printk("Selection failed\n");
#endif
#if ERRORS_ONLY
if (!target) {
static int flag = 0;
if (!flag) /* Skip first failure for all chips. */
++flag;
else
printk("fd_mcs: Selection failed\n");
}
#endif
return 1;
}
static void my_done(struct Scsi_Host *shpnt, int error)
{
if (in_command) {
in_command = 0;
outb(0x00, Interrupt_Cntl_port);
fd_mcs_make_bus_idle(shpnt);
current_SC->result = error;
current_SC->scsi_done(current_SC);
} else {
panic("fd_mcs: my_done() called outside of command\n");
}
#if DEBUG_RACE
in_interrupt_flag = 0;
#endif
}
/* only my_done needs to be protected */
IRQ: Maintain regs pointer globally rather than passing to IRQ handlers Maintain a per-CPU global "struct pt_regs *" variable which can be used instead of passing regs around manually through all ~1800 interrupt handlers in the Linux kernel. The regs pointer is used in few places, but it potentially costs both stack space and code to pass it around. On the FRV arch, removing the regs parameter from all the genirq function results in a 20% speed up of the IRQ exit path (ie: from leaving timer_interrupt() to leaving do_IRQ()). Where appropriate, an arch may override the generic storage facility and do something different with the variable. On FRV, for instance, the address is maintained in GR28 at all times inside the kernel as part of general exception handling. Having looked over the code, it appears that the parameter may be handed down through up to twenty or so layers of functions. Consider a USB character device attached to a USB hub, attached to a USB controller that posts its interrupts through a cascaded auxiliary interrupt controller. A character device driver may want to pass regs to the sysrq handler through the input layer which adds another few layers of parameter passing. I've build this code with allyesconfig for x86_64 and i386. I've runtested the main part of the code on FRV and i386, though I can't test most of the drivers. I've also done partial conversion for powerpc and MIPS - these at least compile with minimal configurations. This will affect all archs. Mostly the changes should be relatively easy. Take do_IRQ(), store the regs pointer at the beginning, saving the old one: struct pt_regs *old_regs = set_irq_regs(regs); And put the old one back at the end: set_irq_regs(old_regs); Don't pass regs through to generic_handle_irq() or __do_IRQ(). In timer_interrupt(), this sort of change will be necessary: - update_process_times(user_mode(regs)); - profile_tick(CPU_PROFILING, regs); + update_process_times(user_mode(get_irq_regs())); + profile_tick(CPU_PROFILING); I'd like to move update_process_times()'s use of get_irq_regs() into itself, except that i386, alone of the archs, uses something other than user_mode(). Some notes on the interrupt handling in the drivers: (*) input_dev() is now gone entirely. The regs pointer is no longer stored in the input_dev struct. (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does something different depending on whether it's been supplied with a regs pointer or not. (*) Various IRQ handler function pointers have been moved to type irq_handler_t. Signed-Off-By: David Howells <dhowells@redhat.com> (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 13:55:46 +00:00
static irqreturn_t fd_mcs_intr(int irq, void *dev_id)
{
unsigned long flags;
int status;
int done = 0;
unsigned data_count, tmp_count;
int i = 0;
struct Scsi_Host *shpnt;
TOTAL_INTR++;
/* search for one adapter-response on shared interrupt */
while ((shpnt = hosts[i++])) {
if ((inb(TMC_Status_port)) & 1)
break;
}
/* return if some other device on this IRQ caused the interrupt */
if (!shpnt) {
return IRQ_NONE;
}
INTR_Processed++;
outb(0x00, Interrupt_Cntl_port);
/* Abort calls my_done, so we do nothing here. */
if (current_SC->SCp.phase & aborted) {
#if DEBUG_ABORT
printk("Interrupt after abort, ignoring\n");
#endif
/* return IRQ_HANDLED; */
}
#if DEBUG_RACE
++in_interrupt_flag;
#endif
if (current_SC->SCp.phase & in_arbitration) {
status = inb(TMC_Status_port); /* Read adapter status */
if (!(status & 0x02)) {
#if EVERY_ACCESS
printk(" AFAIL ");
#endif
spin_lock_irqsave(shpnt->host_lock, flags);
my_done(shpnt, DID_BUS_BUSY << 16);
spin_unlock_irqrestore(shpnt->host_lock, flags);
return IRQ_HANDLED;
}
current_SC->SCp.phase = in_selection;
outb(0x40 | FIFO_COUNT, Interrupt_Cntl_port);
outb(0x82, SCSI_Cntl_port); /* Bus Enable + Select */
outb(adapter_mask | (1 << scmd_id(current_SC)), SCSI_Data_NoACK_port);
/* Stop arbitration and enable parity */
outb(0x10 | PARITY_MASK, TMC_Cntl_port);
#if DEBUG_RACE
in_interrupt_flag = 0;
#endif
return IRQ_HANDLED;
} else if (current_SC->SCp.phase & in_selection) {
status = inb(SCSI_Status_port);
if (!(status & 0x01)) {
/* Try again, for slow devices */
if (fd_mcs_select(shpnt, scmd_id(current_SC))) {
#if EVERY_ACCESS
printk(" SFAIL ");
#endif
spin_lock_irqsave(shpnt->host_lock, flags);
my_done(shpnt, DID_NO_CONNECT << 16);
spin_unlock_irqrestore(shpnt->host_lock, flags);
return IRQ_HANDLED;
} else {
#if EVERY_ACCESS
printk(" AltSel ");
#endif
/* Stop arbitration and enable parity */
outb(0x10 | PARITY_MASK, TMC_Cntl_port);
}
}
current_SC->SCp.phase = in_other;
outb(0x90 | FIFO_COUNT, Interrupt_Cntl_port);
outb(0x80, SCSI_Cntl_port);
#if DEBUG_RACE
in_interrupt_flag = 0;
#endif
return IRQ_HANDLED;
}
/* current_SC->SCp.phase == in_other: this is the body of the routine */
status = inb(SCSI_Status_port);
if (status & 0x10) { /* REQ */
switch (status & 0x0e) {
case 0x08: /* COMMAND OUT */
outb(current_SC->cmnd[current_SC->SCp.sent_command++], Write_SCSI_Data_port);
#if EVERY_ACCESS
printk("CMD = %x,", current_SC->cmnd[current_SC->SCp.sent_command - 1]);
#endif
break;
case 0x00: /* DATA OUT -- tmc18c50/tmc18c30 only */
if (chip != tmc1800 && !current_SC->SCp.have_data_in) {
current_SC->SCp.have_data_in = -1;
outb(0xd0 | PARITY_MASK, TMC_Cntl_port);
}
break;
case 0x04: /* DATA IN -- tmc18c50/tmc18c30 only */
if (chip != tmc1800 && !current_SC->SCp.have_data_in) {
current_SC->SCp.have_data_in = 1;
outb(0x90 | PARITY_MASK, TMC_Cntl_port);
}
break;
case 0x0c: /* STATUS IN */
current_SC->SCp.Status = inb(Read_SCSI_Data_port);
#if EVERY_ACCESS
printk("Status = %x, ", current_SC->SCp.Status);
#endif
#if ERRORS_ONLY
if (current_SC->SCp.Status && current_SC->SCp.Status != 2 && current_SC->SCp.Status != 8) {
printk("ERROR fd_mcs: target = %d, command = %x, status = %x\n", current_SC->device->id, current_SC->cmnd[0], current_SC->SCp.Status);
}
#endif
break;
case 0x0a: /* MESSAGE OUT */
outb(MESSAGE_REJECT, Write_SCSI_Data_port); /* Reject */
break;
case 0x0e: /* MESSAGE IN */
current_SC->SCp.Message = inb(Read_SCSI_Data_port);
#if EVERY_ACCESS
printk("Message = %x, ", current_SC->SCp.Message);
#endif
if (!current_SC->SCp.Message)
++done;
#if DEBUG_MESSAGES || EVERY_ACCESS
if (current_SC->SCp.Message) {
printk("fd_mcs: message = %x\n", current_SC->SCp.Message);
}
#endif
break;
}
}
if (chip == tmc1800 && !current_SC->SCp.have_data_in && (current_SC->SCp.sent_command >= current_SC->cmd_len)) {
/* We have to get the FIFO direction
correct, so I've made a table based
on the SCSI Standard of which commands
appear to require a DATA OUT phase.
*/
/*
p. 94: Command for all device types
CHANGE DEFINITION 40 DATA OUT
COMPARE 39 DATA OUT
COPY 18 DATA OUT
COPY AND VERIFY 3a DATA OUT
INQUIRY 12
LOG SELECT 4c DATA OUT
LOG SENSE 4d
MODE SELECT (6) 15 DATA OUT
MODE SELECT (10) 55 DATA OUT
MODE SENSE (6) 1a
MODE SENSE (10) 5a
READ BUFFER 3c
RECEIVE DIAGNOSTIC RESULTS 1c
REQUEST SENSE 03
SEND DIAGNOSTIC 1d DATA OUT
TEST UNIT READY 00
WRITE BUFFER 3b DATA OUT
p.178: Commands for direct-access devices (not listed on p. 94)
FORMAT UNIT 04 DATA OUT
LOCK-UNLOCK CACHE 36
PRE-FETCH 34
PREVENT-ALLOW MEDIUM REMOVAL 1e
READ (6)/RECEIVE 08
READ (10) 3c
READ CAPACITY 25
READ DEFECT DATA (10) 37
READ LONG 3e
REASSIGN BLOCKS 07 DATA OUT
RELEASE 17
RESERVE 16 DATA OUT
REZERO UNIT/REWIND 01
SEARCH DATA EQUAL (10) 31 DATA OUT
SEARCH DATA HIGH (10) 30 DATA OUT
SEARCH DATA LOW (10) 32 DATA OUT
SEEK (6) 0b
SEEK (10) 2b
SET LIMITS (10) 33
START STOP UNIT 1b
SYNCHRONIZE CACHE 35
VERIFY (10) 2f
WRITE (6)/PRINT/SEND 0a DATA OUT
WRITE (10)/SEND 2a DATA OUT
WRITE AND VERIFY (10) 2e DATA OUT
WRITE LONG 3f DATA OUT
WRITE SAME 41 DATA OUT ?
p. 261: Commands for sequential-access devices (not previously listed)
ERASE 19
LOAD UNLOAD 1b
LOCATE 2b
READ BLOCK LIMITS 05
READ POSITION 34
READ REVERSE 0f
RECOVER BUFFERED DATA 14
SPACE 11
WRITE FILEMARKS 10 ?
p. 298: Commands for printer devices (not previously listed)
****** NOT SUPPORTED BY THIS DRIVER, since 0b is SEEK (6) *****
SLEW AND PRINT 0b DATA OUT -- same as seek
STOP PRINT 1b
SYNCHRONIZE BUFFER 10
p. 315: Commands for processor devices (not previously listed)
p. 321: Commands for write-once devices (not previously listed)
MEDIUM SCAN 38
READ (12) a8
SEARCH DATA EQUAL (12) b1 DATA OUT
SEARCH DATA HIGH (12) b0 DATA OUT
SEARCH DATA LOW (12) b2 DATA OUT
SET LIMITS (12) b3
VERIFY (12) af
WRITE (12) aa DATA OUT
WRITE AND VERIFY (12) ae DATA OUT
p. 332: Commands for CD-ROM devices (not previously listed)
PAUSE/RESUME 4b
PLAY AUDIO (10) 45
PLAY AUDIO (12) a5
PLAY AUDIO MSF 47
PLAY TRACK RELATIVE (10) 49
PLAY TRACK RELATIVE (12) a9
READ HEADER 44
READ SUB-CHANNEL 42
READ TOC 43
p. 370: Commands for scanner devices (not previously listed)
GET DATA BUFFER STATUS 34
GET WINDOW 25
OBJECT POSITION 31
SCAN 1b
SET WINDOW 24 DATA OUT
p. 391: Commands for optical memory devices (not listed)
ERASE (10) 2c
ERASE (12) ac
MEDIUM SCAN 38 DATA OUT
READ DEFECT DATA (12) b7
READ GENERATION 29
READ UPDATED BLOCK 2d
UPDATE BLOCK 3d DATA OUT
p. 419: Commands for medium changer devices (not listed)
EXCHANGE MEDIUM 46
INITIALIZE ELEMENT STATUS 07
MOVE MEDIUM a5
POSITION TO ELEMENT 2b
READ ELEMENT STATUS b8
REQUEST VOL. ELEMENT ADDRESS b5
SEND VOLUME TAG b6 DATA OUT
p. 454: Commands for communications devices (not listed previously)
GET MESSAGE (6) 08
GET MESSAGE (10) 28
GET MESSAGE (12) a8
*/
switch (current_SC->cmnd[0]) {
case CHANGE_DEFINITION:
case COMPARE:
case COPY:
case COPY_VERIFY:
case LOG_SELECT:
case MODE_SELECT:
case MODE_SELECT_10:
case SEND_DIAGNOSTIC:
case WRITE_BUFFER:
case FORMAT_UNIT:
case REASSIGN_BLOCKS:
case RESERVE:
case SEARCH_EQUAL:
case SEARCH_HIGH:
case SEARCH_LOW:
case WRITE_6:
case WRITE_10:
case WRITE_VERIFY:
case 0x3f:
case 0x41:
case 0xb1:
case 0xb0:
case 0xb2:
case 0xaa:
case 0xae:
case 0x24:
case 0x38:
case 0x3d:
case 0xb6:
case 0xea: /* alternate number for WRITE LONG */
current_SC->SCp.have_data_in = -1;
outb(0xd0 | PARITY_MASK, TMC_Cntl_port);
break;
case 0x00:
default:
current_SC->SCp.have_data_in = 1;
outb(0x90 | PARITY_MASK, TMC_Cntl_port);
break;
}
}
if (current_SC->SCp.have_data_in == -1) { /* DATA OUT */
while ((data_count = FIFO_Size - inw(FIFO_Data_Count_port)) > 512) {
#if EVERY_ACCESS
printk("DC=%d, ", data_count);
#endif
if (data_count > current_SC->SCp.this_residual)
data_count = current_SC->SCp.this_residual;
if (data_count > 0) {
#if EVERY_ACCESS
printk("%d OUT, ", data_count);
#endif
if (data_count == 1) {
Bytes_Written++;
outb(*current_SC->SCp.ptr++, Write_FIFO_port);
--current_SC->SCp.this_residual;
} else {
data_count >>= 1;
tmp_count = data_count << 1;
outsw(Write_FIFO_port, current_SC->SCp.ptr, data_count);
current_SC->SCp.ptr += tmp_count;
Bytes_Written += tmp_count;
current_SC->SCp.this_residual -= tmp_count;
}
}
if (!current_SC->SCp.this_residual) {
if (current_SC->SCp.buffers_residual) {
--current_SC->SCp.buffers_residual;
++current_SC->SCp.buffer;
current_SC->SCp.ptr = sg_virt(current_SC->SCp.buffer);
current_SC->SCp.this_residual = current_SC->SCp.buffer->length;
} else
break;
}
}
} else if (current_SC->SCp.have_data_in == 1) { /* DATA IN */
while ((data_count = inw(FIFO_Data_Count_port)) > 0) {
#if EVERY_ACCESS
printk("DC=%d, ", data_count);
#endif
if (data_count > current_SC->SCp.this_residual)
data_count = current_SC->SCp.this_residual;
if (data_count) {
#if EVERY_ACCESS
printk("%d IN, ", data_count);
#endif
if (data_count == 1) {
Bytes_Read++;
*current_SC->SCp.ptr++ = inb(Read_FIFO_port);
--current_SC->SCp.this_residual;
} else {
data_count >>= 1; /* Number of words */
tmp_count = data_count << 1;
insw(Read_FIFO_port, current_SC->SCp.ptr, data_count);
current_SC->SCp.ptr += tmp_count;
Bytes_Read += tmp_count;
current_SC->SCp.this_residual -= tmp_count;
}
}
if (!current_SC->SCp.this_residual && current_SC->SCp.buffers_residual) {
--current_SC->SCp.buffers_residual;
++current_SC->SCp.buffer;
current_SC->SCp.ptr = sg_virt(current_SC->SCp.buffer);
current_SC->SCp.this_residual = current_SC->SCp.buffer->length;
}
}
}
if (done) {
#if EVERY_ACCESS
printk(" ** IN DONE %d ** ", current_SC->SCp.have_data_in);
#endif
#if ERRORS_ONLY
if (current_SC->cmnd[0] == REQUEST_SENSE && !current_SC->SCp.Status) {
if ((unsigned char) (*((char *) current_SC->request_buffer + 2)) & 0x0f) {
unsigned char key;
unsigned char code;
unsigned char qualifier;
key = (unsigned char) (*((char *) current_SC->request_buffer + 2)) & 0x0f;
code = (unsigned char) (*((char *) current_SC->request_buffer + 12));
qualifier = (unsigned char) (*((char *) current_SC->request_buffer + 13));
if (key != UNIT_ATTENTION && !(key == NOT_READY && code == 0x04 && (!qualifier || qualifier == 0x02 || qualifier == 0x01))
&& !(key == ILLEGAL_REQUEST && (code == 0x25 || code == 0x24 || !code)))
printk("fd_mcs: REQUEST SENSE " "Key = %x, Code = %x, Qualifier = %x\n", key, code, qualifier);
}
}
#endif
#if EVERY_ACCESS
printk("BEFORE MY_DONE. . .");
#endif
spin_lock_irqsave(shpnt->host_lock, flags);
my_done(shpnt, (current_SC->SCp.Status & 0xff)
| ((current_SC->SCp.Message & 0xff) << 8) | (DID_OK << 16));
spin_unlock_irqrestore(shpnt->host_lock, flags);
#if EVERY_ACCESS
printk("RETURNING.\n");
#endif
} else {
if (current_SC->SCp.phase & disconnect) {
outb(0xd0 | FIFO_COUNT, Interrupt_Cntl_port);
outb(0x00, SCSI_Cntl_port);
} else {
outb(0x90 | FIFO_COUNT, Interrupt_Cntl_port);
}
}
#if DEBUG_RACE
in_interrupt_flag = 0;
#endif
return IRQ_HANDLED;
}
static int fd_mcs_release(struct Scsi_Host *shpnt)
{
int i, this_host, irq_usage;
release_region(shpnt->io_port, shpnt->n_io_port);
this_host = -1;
irq_usage = 0;
for (i = 0; i < found; i++) {
if (shpnt == hosts[i])
this_host = i;
if (shpnt->irq == hosts[i]->irq)
irq_usage++;
}
/* only for the last one */
if (1 == irq_usage)
free_irq(shpnt->irq, hosts);
found--;
for (i = this_host; i < found; i++)
hosts[i] = hosts[i + 1];
hosts[found] = NULL;
return 0;
}
static int fd_mcs_queue(Scsi_Cmnd * SCpnt, void (*done) (Scsi_Cmnd *))
{
struct Scsi_Host *shpnt = SCpnt->device->host;
if (in_command) {
panic("fd_mcs: fd_mcs_queue() NOT REENTRANT!\n");
}
#if EVERY_ACCESS
printk("queue: target = %d cmnd = 0x%02x pieces = %d size = %u\n", SCpnt->target, *(unsigned char *) SCpnt->cmnd, SCpnt->use_sg, SCpnt->request_bufflen);
#endif
fd_mcs_make_bus_idle(shpnt);
SCpnt->scsi_done = done; /* Save this for the done function */
current_SC = SCpnt;
/* Initialize static data */
if (current_SC->use_sg) {
current_SC->SCp.buffer = (struct scatterlist *) current_SC->request_buffer;
current_SC->SCp.ptr = sg_virt(current_SC->SCp.buffer);
current_SC->SCp.this_residual = current_SC->SCp.buffer->length;
current_SC->SCp.buffers_residual = current_SC->use_sg - 1;
} else {
current_SC->SCp.ptr = (char *) current_SC->request_buffer;
current_SC->SCp.this_residual = current_SC->request_bufflen;
current_SC->SCp.buffer = NULL;
current_SC->SCp.buffers_residual = 0;
}
current_SC->SCp.Status = 0;
current_SC->SCp.Message = 0;
current_SC->SCp.have_data_in = 0;
current_SC->SCp.sent_command = 0;
current_SC->SCp.phase = in_arbitration;
/* Start arbitration */
outb(0x00, Interrupt_Cntl_port);
outb(0x00, SCSI_Cntl_port); /* Disable data drivers */
outb(adapter_mask, SCSI_Data_NoACK_port); /* Set our id bit */
in_command = 1;
outb(0x20, Interrupt_Cntl_port);
outb(0x14 | PARITY_MASK, TMC_Cntl_port); /* Start arbitration */
return 0;
}
#if DEBUG_ABORT || DEBUG_RESET
static void fd_mcs_print_info(Scsi_Cmnd * SCpnt)
{
unsigned int imr;
unsigned int irr;
unsigned int isr;
struct Scsi_Host *shpnt = SCpnt->host;
if (!SCpnt || !SCpnt->host) {
printk("fd_mcs: cannot provide detailed information\n");
}
printk("%s\n", fd_mcs_info(SCpnt->host));
print_banner(SCpnt->host);
switch (SCpnt->SCp.phase) {
case in_arbitration:
printk("arbitration ");
break;
case in_selection:
printk("selection ");
break;
case in_other:
printk("other ");
break;
default:
printk("unknown ");
break;
}
printk("(%d), target = %d cmnd = 0x%02x pieces = %d size = %u\n", SCpnt->SCp.phase, SCpnt->device->id, *(unsigned char *) SCpnt->cmnd, SCpnt->use_sg, SCpnt->request_bufflen);
printk("sent_command = %d, have_data_in = %d, timeout = %d\n", SCpnt->SCp.sent_command, SCpnt->SCp.have_data_in, SCpnt->timeout);
#if DEBUG_RACE
printk("in_interrupt_flag = %d\n", in_interrupt_flag);
#endif
imr = (inb(0x0a1) << 8) + inb(0x21);
outb(0x0a, 0xa0);
irr = inb(0xa0) << 8;
outb(0x0a, 0x20);
irr += inb(0x20);
outb(0x0b, 0xa0);
isr = inb(0xa0) << 8;
outb(0x0b, 0x20);
isr += inb(0x20);
/* Print out interesting information */
printk("IMR = 0x%04x", imr);
if (imr & (1 << shpnt->irq))
printk(" (masked)");
printk(", IRR = 0x%04x, ISR = 0x%04x\n", irr, isr);
printk("SCSI Status = 0x%02x\n", inb(SCSI_Status_port));
printk("TMC Status = 0x%02x", inb(TMC_Status_port));
if (inb(TMC_Status_port) & 1)
printk(" (interrupt)");
printk("\n");
printk("Interrupt Status = 0x%02x", inb(Interrupt_Status_port));
if (inb(Interrupt_Status_port) & 0x08)
printk(" (enabled)");
printk("\n");
if (chip == tmc18c50 || chip == tmc18c30) {
printk("FIFO Status = 0x%02x\n", inb(shpnt->io_port + FIFO_Status));
printk("Int. Condition = 0x%02x\n", inb(shpnt->io_port + Interrupt_Cond));
}
printk("Configuration 1 = 0x%02x\n", inb(shpnt->io_port + Configuration1));
if (chip == tmc18c50 || chip == tmc18c30)
printk("Configuration 2 = 0x%02x\n", inb(shpnt->io_port + Configuration2));
}
#endif
static int fd_mcs_abort(Scsi_Cmnd * SCpnt)
{
struct Scsi_Host *shpnt = SCpnt->device->host;
unsigned long flags;
#if EVERY_ACCESS || ERRORS_ONLY || DEBUG_ABORT
printk("fd_mcs: abort ");
#endif
spin_lock_irqsave(shpnt->host_lock, flags);
if (!in_command) {
#if EVERY_ACCESS || ERRORS_ONLY
printk(" (not in command)\n");
#endif
spin_unlock_irqrestore(shpnt->host_lock, flags);
return FAILED;
} else
printk("\n");
#if DEBUG_ABORT
fd_mcs_print_info(SCpnt);
#endif
fd_mcs_make_bus_idle(shpnt);
current_SC->SCp.phase |= aborted;
current_SC->result = DID_ABORT << 16;
/* Aborts are not done well. . . */
my_done(shpnt, DID_ABORT << 16);
spin_unlock_irqrestore(shpnt->host_lock, flags);
return SUCCESS;
}
static int fd_mcs_bus_reset(Scsi_Cmnd * SCpnt) {
struct Scsi_Host *shpnt = SCpnt->device->host;
unsigned long flags;
#if DEBUG_RESET
static int called_once = 0;
#endif
#if ERRORS_ONLY
if (SCpnt)
printk("fd_mcs: SCSI Bus Reset\n");
#endif
#if DEBUG_RESET
if (called_once)
fd_mcs_print_info(current_SC);
called_once = 1;
#endif
spin_lock_irqsave(shpnt->host_lock, flags);
outb(1, SCSI_Cntl_port);
do_pause(2);
outb(0, SCSI_Cntl_port);
do_pause(115);
outb(0, SCSI_Mode_Cntl_port);
outb(PARITY_MASK, TMC_Cntl_port);
spin_unlock_irqrestore(shpnt->host_lock, flags);
/* Unless this is the very first call (i.e., SCPnt == NULL), everything
is probably hosed at this point. We will, however, try to keep
things going by informing the high-level code that we need help. */
return SUCCESS;
}
#include <scsi/scsi_ioctl.h>
static int fd_mcs_biosparam(struct scsi_device * disk, struct block_device *bdev,
sector_t capacity, int *info_array)
{
unsigned char *p = scsi_bios_ptable(bdev);
int size = capacity;
/* BIOS >= 3.4 for MCA cards */
/* This algorithm was provided by Future Domain (much thanks!). */
if (p && p[65] == 0xaa && p[64] == 0x55 /* Partition table valid */
&& p[4]) { /* Partition type */
/* The partition table layout is as follows:
Start: 0x1b3h
Offset: 0 = partition status
1 = starting head
2 = starting sector and cylinder (word, encoded)
4 = partition type
5 = ending head
6 = ending sector and cylinder (word, encoded)
8 = starting absolute sector (double word)
c = number of sectors (double word)
Signature: 0x1fe = 0x55aa
So, this algorithm assumes:
1) the first partition table is in use,
2) the data in the first entry is correct, and
3) partitions never divide cylinders
Note that (1) may be FALSE for NetBSD (and other BSD flavors),
as well as for Linux. Note also, that Linux doesn't pay any
attention to the fields that are used by this algorithm -- it
only uses the absolute sector data. Recent versions of Linux's
fdisk(1) will fill this data in correctly, and forthcoming
versions will check for consistency.
Checking for a non-zero partition type is not part of the
Future Domain algorithm, but it seemed to be a reasonable thing
to do, especially in the Linux and BSD worlds. */
info_array[0] = p[5] + 1; /* heads */
info_array[1] = p[6] & 0x3f; /* sectors */
} else {
/* Note that this new method guarantees that there will always be
less than 1024 cylinders on a platter. This is good for drives
up to approximately 7.85GB (where 1GB = 1024 * 1024 kB). */
if ((unsigned int) size >= 0x7e0000U)
{
info_array[0] = 0xff; /* heads = 255 */
info_array[1] = 0x3f; /* sectors = 63 */
} else if ((unsigned int) size >= 0x200000U) {
info_array[0] = 0x80; /* heads = 128 */
info_array[1] = 0x3f; /* sectors = 63 */
} else {
info_array[0] = 0x40; /* heads = 64 */
info_array[1] = 0x20; /* sectors = 32 */
}
}
/* For both methods, compute the cylinders */
info_array[2] = (unsigned int) size / (info_array[0] * info_array[1]);
kfree(p);
return 0;
}
static struct scsi_host_template driver_template = {
.proc_name = "fd_mcs",
.proc_info = fd_mcs_proc_info,
.detect = fd_mcs_detect,
.release = fd_mcs_release,
.info = fd_mcs_info,
.queuecommand = fd_mcs_queue,
.eh_abort_handler = fd_mcs_abort,
.eh_bus_reset_handler = fd_mcs_bus_reset,
.bios_param = fd_mcs_biosparam,
.can_queue = 1,
.this_id = 7,
.sg_tablesize = 64,
.cmd_per_lun = 1,
.use_clustering = DISABLE_CLUSTERING,
};
#include "scsi_module.c"
MODULE_LICENSE("GPL");