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linux-next/drivers/isdn/hisax/avm_a1p.c
David Howells 7d12e780e0 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 15:10:12 +01:00

269 lines
7.0 KiB
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/* $Id: avm_a1p.c,v 2.9.2.5 2004/01/24 20:47:19 keil Exp $
*
* low level stuff for the following AVM cards:
* A1 PCMCIA
* FRITZ!Card PCMCIA
* FRITZ!Card PCMCIA 2.0
*
* Author Carsten Paeth
* Copyright by Carsten Paeth <calle@calle.de>
*
* This software may be used and distributed according to the terms
* of the GNU General Public License, incorporated herein by reference.
*
*/
#include <linux/init.h>
#include "hisax.h"
#include "isac.h"
#include "hscx.h"
#include "isdnl1.h"
/* register offsets */
#define ADDRREG_OFFSET 0x02
#define DATAREG_OFFSET 0x03
#define ASL0_OFFSET 0x04
#define ASL1_OFFSET 0x05
#define MODREG_OFFSET 0x06
#define VERREG_OFFSET 0x07
/* address offsets */
#define ISAC_FIFO_OFFSET 0x00
#define ISAC_REG_OFFSET 0x20
#define HSCX_CH_DIFF 0x40
#define HSCX_FIFO_OFFSET 0x80
#define HSCX_REG_OFFSET 0xa0
/* read bits ASL0 */
#define ASL0_R_TIMER 0x10 /* active low */
#define ASL0_R_ISAC 0x20 /* active low */
#define ASL0_R_HSCX 0x40 /* active low */
#define ASL0_R_TESTBIT 0x80
#define ASL0_R_IRQPENDING (ASL0_R_ISAC|ASL0_R_HSCX|ASL0_R_TIMER)
/* write bits ASL0 */
#define ASL0_W_RESET 0x01
#define ASL0_W_TDISABLE 0x02
#define ASL0_W_TRESET 0x04
#define ASL0_W_IRQENABLE 0x08
#define ASL0_W_TESTBIT 0x80
/* write bits ASL1 */
#define ASL1_W_LED0 0x10
#define ASL1_W_LED1 0x20
#define ASL1_W_ENABLE_S0 0xC0
#define byteout(addr,val) outb(val,addr)
#define bytein(addr) inb(addr)
static const char *avm_revision = "$Revision: 2.9.2.5 $";
static inline u_char
ReadISAC(struct IsdnCardState *cs, u_char offset)
{
u_char ret;
offset -= 0x20;
byteout(cs->hw.avm.cfg_reg+ADDRREG_OFFSET,ISAC_REG_OFFSET+offset);
ret = bytein(cs->hw.avm.cfg_reg+DATAREG_OFFSET);
return ret;
}
static inline void
WriteISAC(struct IsdnCardState *cs, u_char offset, u_char value)
{
offset -= 0x20;
byteout(cs->hw.avm.cfg_reg+ADDRREG_OFFSET,ISAC_REG_OFFSET+offset);
byteout(cs->hw.avm.cfg_reg+DATAREG_OFFSET, value);
}
static inline void
ReadISACfifo(struct IsdnCardState *cs, u_char * data, int size)
{
byteout(cs->hw.avm.cfg_reg+ADDRREG_OFFSET,ISAC_FIFO_OFFSET);
insb(cs->hw.avm.cfg_reg+DATAREG_OFFSET, data, size);
}
static inline void
WriteISACfifo(struct IsdnCardState *cs, u_char * data, int size)
{
byteout(cs->hw.avm.cfg_reg+ADDRREG_OFFSET,ISAC_FIFO_OFFSET);
outsb(cs->hw.avm.cfg_reg+DATAREG_OFFSET, data, size);
}
static inline u_char
ReadHSCX(struct IsdnCardState *cs, int hscx, u_char offset)
{
u_char ret;
offset -= 0x20;
byteout(cs->hw.avm.cfg_reg+ADDRREG_OFFSET,
HSCX_REG_OFFSET+hscx*HSCX_CH_DIFF+offset);
ret = bytein(cs->hw.avm.cfg_reg+DATAREG_OFFSET);
return ret;
}
static inline void
WriteHSCX(struct IsdnCardState *cs, int hscx, u_char offset, u_char value)
{
offset -= 0x20;
byteout(cs->hw.avm.cfg_reg+ADDRREG_OFFSET,
HSCX_REG_OFFSET+hscx*HSCX_CH_DIFF+offset);
byteout(cs->hw.avm.cfg_reg+DATAREG_OFFSET, value);
}
static inline void
ReadHSCXfifo(struct IsdnCardState *cs, int hscx, u_char * data, int size)
{
byteout(cs->hw.avm.cfg_reg+ADDRREG_OFFSET,
HSCX_FIFO_OFFSET+hscx*HSCX_CH_DIFF);
insb(cs->hw.avm.cfg_reg+DATAREG_OFFSET, data, size);
}
static inline void
WriteHSCXfifo(struct IsdnCardState *cs, int hscx, u_char * data, int size)
{
byteout(cs->hw.avm.cfg_reg+ADDRREG_OFFSET,
HSCX_FIFO_OFFSET+hscx*HSCX_CH_DIFF);
outsb(cs->hw.avm.cfg_reg+DATAREG_OFFSET, data, size);
}
/*
* fast interrupt HSCX stuff goes here
*/
#define READHSCX(cs, nr, reg) ReadHSCX(cs, nr, reg)
#define WRITEHSCX(cs, nr, reg, data) WriteHSCX(cs, nr, reg, data)
#define READHSCXFIFO(cs, nr, ptr, cnt) ReadHSCXfifo(cs, nr, ptr, cnt)
#define WRITEHSCXFIFO(cs, nr, ptr, cnt) WriteHSCXfifo(cs, nr, ptr, cnt)
#include "hscx_irq.c"
static irqreturn_t
avm_a1p_interrupt(int intno, void *dev_id)
{
struct IsdnCardState *cs = dev_id;
u_char val, sval;
u_long flags;
spin_lock_irqsave(&cs->lock, flags);
while ((sval = (~bytein(cs->hw.avm.cfg_reg+ASL0_OFFSET) & ASL0_R_IRQPENDING))) {
if (cs->debug & L1_DEB_INTSTAT)
debugl1(cs, "avm IntStatus %x", sval);
if (sval & ASL0_R_HSCX) {
val = ReadHSCX(cs, 1, HSCX_ISTA);
if (val)
hscx_int_main(cs, val);
}
if (sval & ASL0_R_ISAC) {
val = ReadISAC(cs, ISAC_ISTA);
if (val)
isac_interrupt(cs, val);
}
}
WriteHSCX(cs, 0, HSCX_MASK, 0xff);
WriteHSCX(cs, 1, HSCX_MASK, 0xff);
WriteISAC(cs, ISAC_MASK, 0xff);
WriteISAC(cs, ISAC_MASK, 0x00);
WriteHSCX(cs, 0, HSCX_MASK, 0x00);
WriteHSCX(cs, 1, HSCX_MASK, 0x00);
spin_unlock_irqrestore(&cs->lock, flags);
return IRQ_HANDLED;
}
static int
AVM_card_msg(struct IsdnCardState *cs, int mt, void *arg)
{
u_long flags;
switch (mt) {
case CARD_RESET:
spin_lock_irqsave(&cs->lock, flags);
byteout(cs->hw.avm.cfg_reg+ASL0_OFFSET,0x00);
HZDELAY(HZ / 5 + 1);
byteout(cs->hw.avm.cfg_reg+ASL0_OFFSET,ASL0_W_RESET);
HZDELAY(HZ / 5 + 1);
byteout(cs->hw.avm.cfg_reg+ASL0_OFFSET,0x00);
spin_unlock_irqrestore(&cs->lock, flags);
return 0;
case CARD_RELEASE:
/* free_irq is done in HiSax_closecard(). */
/* free_irq(cs->irq, cs); */
return 0;
case CARD_INIT:
spin_lock_irqsave(&cs->lock, flags);
byteout(cs->hw.avm.cfg_reg+ASL0_OFFSET,ASL0_W_TDISABLE|ASL0_W_TRESET|ASL0_W_IRQENABLE);
clear_pending_isac_ints(cs);
clear_pending_hscx_ints(cs);
inithscxisac(cs, 1);
inithscxisac(cs, 2);
spin_unlock_irqrestore(&cs->lock, flags);
return 0;
case CARD_TEST:
/* we really don't need it for the PCMCIA Version */
return 0;
default:
/* all card drivers ignore others, so we do the same */
return 0;
}
return 0;
}
int
setup_avm_a1_pcmcia(struct IsdnCard *card)
{
u_char model, vers;
struct IsdnCardState *cs = card->cs;
char tmp[64];
strcpy(tmp, avm_revision);
printk(KERN_INFO "HiSax: AVM A1 PCMCIA driver Rev. %s\n",
HiSax_getrev(tmp));
if (cs->typ != ISDN_CTYPE_A1_PCMCIA)
return (0);
cs->hw.avm.cfg_reg = card->para[1];
cs->irq = card->para[0];
byteout(cs->hw.avm.cfg_reg+ASL1_OFFSET, ASL1_W_ENABLE_S0);
byteout(cs->hw.avm.cfg_reg+ASL0_OFFSET,0x00);
HZDELAY(HZ / 5 + 1);
byteout(cs->hw.avm.cfg_reg+ASL0_OFFSET,ASL0_W_RESET);
HZDELAY(HZ / 5 + 1);
byteout(cs->hw.avm.cfg_reg+ASL0_OFFSET,0x00);
byteout(cs->hw.avm.cfg_reg+ASL0_OFFSET, ASL0_W_TDISABLE|ASL0_W_TRESET);
model = bytein(cs->hw.avm.cfg_reg+MODREG_OFFSET);
vers = bytein(cs->hw.avm.cfg_reg+VERREG_OFFSET);
printk(KERN_INFO "AVM A1 PCMCIA: io 0x%x irq %d model %d version %d\n",
cs->hw.avm.cfg_reg, cs->irq, model, vers);
setup_isac(cs);
cs->readisac = &ReadISAC;
cs->writeisac = &WriteISAC;
cs->readisacfifo = &ReadISACfifo;
cs->writeisacfifo = &WriteISACfifo;
cs->BC_Read_Reg = &ReadHSCX;
cs->BC_Write_Reg = &WriteHSCX;
cs->BC_Send_Data = &hscx_fill_fifo;
cs->cardmsg = &AVM_card_msg;
cs->irq_flags = IRQF_SHARED;
cs->irq_func = &avm_a1p_interrupt;
ISACVersion(cs, "AVM A1 PCMCIA:");
if (HscxVersion(cs, "AVM A1 PCMCIA:")) {
printk(KERN_WARNING
"AVM A1 PCMCIA: wrong HSCX versions check IO address\n");
return (0);
}
return (1);
}
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