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linux/sound/isa/sb/sb8.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

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/*
* Driver for SoundBlaster 1.0/2.0/Pro soundcards and compatible
* Copyright (c) by Jaroslav Kysela <perex@suse.cz>
*
*
* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <sound/driver.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/ioport.h>
#include <linux/moduleparam.h>
#include <sound/core.h>
#include <sound/sb.h>
#include <sound/opl3.h>
#include <sound/initval.h>
MODULE_AUTHOR("Jaroslav Kysela <perex@suse.cz>");
MODULE_DESCRIPTION("Sound Blaster 1.0/2.0/Pro");
MODULE_LICENSE("GPL");
MODULE_SUPPORTED_DEVICE("{{Creative Labs,SB 1.0/SB 2.0/SB Pro}}");
static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX; /* Index 0-MAX */
static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR; /* ID for this card */
static int enable[SNDRV_CARDS] = SNDRV_DEFAULT_ENABLE; /* Enable this card */
static long port[SNDRV_CARDS] = SNDRV_DEFAULT_PORT; /* 0x220,0x240,0x260 */
static int irq[SNDRV_CARDS] = SNDRV_DEFAULT_IRQ; /* 5,7,9,10 */
static int dma8[SNDRV_CARDS] = SNDRV_DEFAULT_DMA; /* 1,3 */
module_param_array(index, int, NULL, 0444);
MODULE_PARM_DESC(index, "Index value for Sound Blaster soundcard.");
module_param_array(id, charp, NULL, 0444);
MODULE_PARM_DESC(id, "ID string for Sound Blaster soundcard.");
module_param_array(enable, bool, NULL, 0444);
MODULE_PARM_DESC(enable, "Enable Sound Blaster soundcard.");
module_param_array(port, long, NULL, 0444);
MODULE_PARM_DESC(port, "Port # for SB8 driver.");
module_param_array(irq, int, NULL, 0444);
MODULE_PARM_DESC(irq, "IRQ # for SB8 driver.");
module_param_array(dma8, int, NULL, 0444);
MODULE_PARM_DESC(dma8, "8-bit DMA # for SB8 driver.");
static struct platform_device *devices[SNDRV_CARDS];
struct snd_sb8 {
struct resource *fm_res; /* used to block FM i/o region for legacy cards */
struct snd_sb *chip;
};
static irqreturn_t snd_sb8_interrupt(int irq, void *dev_id)
{
struct snd_sb *chip = dev_id;
if (chip->open & SB_OPEN_PCM) {
return snd_sb8dsp_interrupt(chip);
} else {
return snd_sb8dsp_midi_interrupt(chip);
}
}
static void snd_sb8_free(struct snd_card *card)
{
struct snd_sb8 *acard = (struct snd_sb8 *)card->private_data;
if (acard == NULL)
return;
release_and_free_resource(acard->fm_res);
}
static int __init snd_sb8_probe(struct platform_device *pdev)
{
int dev = pdev->id;
struct snd_sb *chip;
struct snd_card *card;
struct snd_sb8 *acard;
struct snd_opl3 *opl3;
int err;
card = snd_card_new(index[dev], id[dev], THIS_MODULE,
sizeof(struct snd_sb8));
if (card == NULL)
return -ENOMEM;
acard = card->private_data;
card->private_free = snd_sb8_free;
/* block the 0x388 port to avoid PnP conflicts */
acard->fm_res = request_region(0x388, 4, "SoundBlaster FM");
if (port[dev] != SNDRV_AUTO_PORT) {
if ((err = snd_sbdsp_create(card, port[dev], irq[dev],
snd_sb8_interrupt,
dma8[dev],
-1,
SB_HW_AUTO,
&chip)) < 0)
goto _err;
} else {
/* auto-probe legacy ports */
static unsigned long possible_ports[] = {
0x220, 0x240, 0x260,
};
int i;
for (i = 0; i < ARRAY_SIZE(possible_ports); i++) {
err = snd_sbdsp_create(card, possible_ports[i],
irq[dev],
snd_sb8_interrupt,
dma8[dev],
-1,
SB_HW_AUTO,
&chip);
if (err >= 0) {
port[dev] = possible_ports[i];
break;
}
}
if (i >= ARRAY_SIZE(possible_ports))
goto _err;
}
acard->chip = chip;
if (chip->hardware >= SB_HW_16) {
if (chip->hardware == SB_HW_ALS100)
snd_printk(KERN_WARNING "ALS100 chip detected at 0x%lx, try snd-als100 module\n",
port[dev]);
else
snd_printk(KERN_WARNING "SB 16 chip detected at 0x%lx, try snd-sb16 module\n",
port[dev]);
err = -ENODEV;
goto _err;
}
if ((err = snd_sb8dsp_pcm(chip, 0, NULL)) < 0)
goto _err;
if ((err = snd_sbmixer_new(chip)) < 0)
goto _err;
if (chip->hardware == SB_HW_10 || chip->hardware == SB_HW_20) {
if ((err = snd_opl3_create(card, chip->port + 8, 0,
OPL3_HW_AUTO, 1,
&opl3)) < 0) {
snd_printk(KERN_WARNING "sb8: no OPL device at 0x%lx\n", chip->port + 8);
}
} else {
if ((err = snd_opl3_create(card, chip->port, chip->port + 2,
OPL3_HW_AUTO, 1,
&opl3)) < 0) {
snd_printk(KERN_WARNING "sb8: no OPL device at 0x%lx-0x%lx\n",
chip->port, chip->port + 2);
}
}
if (err >= 0) {
if ((err = snd_opl3_hwdep_new(opl3, 0, 1, NULL)) < 0)
goto _err;
}
if ((err = snd_sb8dsp_midi(chip, 0, NULL)) < 0)
goto _err;
strcpy(card->driver, chip->hardware == SB_HW_PRO ? "SB Pro" : "SB8");
strcpy(card->shortname, chip->name);
sprintf(card->longname, "%s at 0x%lx, irq %d, dma %d",
chip->name,
chip->port,
irq[dev], dma8[dev]);
snd_card_set_dev(card, &pdev->dev);
if ((err = snd_card_register(card)) < 0)
goto _err;
platform_set_drvdata(pdev, card);
return 0;
_err:
snd_card_free(card);
return err;
}
static int snd_sb8_remove(struct platform_device *pdev)
{
snd_card_free(platform_get_drvdata(pdev));
platform_set_drvdata(pdev, NULL);
return 0;
}
#ifdef CONFIG_PM
static int snd_sb8_suspend(struct platform_device *dev, pm_message_t state)
{
struct snd_card *card = platform_get_drvdata(dev);
struct snd_sb8 *acard = card->private_data;
struct snd_sb *chip = acard->chip;
snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
snd_pcm_suspend_all(chip->pcm);
snd_sbmixer_suspend(chip);
return 0;
}
static int snd_sb8_resume(struct platform_device *dev)
{
struct snd_card *card = platform_get_drvdata(dev);
struct snd_sb8 *acard = card->private_data;
struct snd_sb *chip = acard->chip;
snd_sbdsp_reset(chip);
snd_sbmixer_resume(chip);
snd_power_change_state(card, SNDRV_CTL_POWER_D0);
return 0;
}
#endif
#define SND_SB8_DRIVER "snd_sb8"
static struct platform_driver snd_sb8_driver = {
.probe = snd_sb8_probe,
.remove = snd_sb8_remove,
#ifdef CONFIG_PM
.suspend = snd_sb8_suspend,
.resume = snd_sb8_resume,
#endif
.driver = {
.name = SND_SB8_DRIVER
},
};
static void __init_or_module snd_sb8_unregister_all(void)
{
int i;
for (i = 0; i < ARRAY_SIZE(devices); ++i)
platform_device_unregister(devices[i]);
platform_driver_unregister(&snd_sb8_driver);
}
static int __init alsa_card_sb8_init(void)
{
int i, cards, err;
err = platform_driver_register(&snd_sb8_driver);
if (err < 0)
return err;
cards = 0;
for (i = 0; i < SNDRV_CARDS; i++) {
struct platform_device *device;
if (! enable[i])
continue;
device = platform_device_register_simple(SND_SB8_DRIVER,
i, NULL, 0);
if (IS_ERR(device))
continue;
if (!platform_get_drvdata(device)) {
platform_device_unregister(device);
continue;
}
devices[i] = device;
cards++;
}
if (!cards) {
#ifdef MODULE
snd_printk(KERN_ERR "Sound Blaster soundcard not found or device busy\n");
#endif
snd_sb8_unregister_all();
return -ENODEV;
}
return 0;
}
static void __exit alsa_card_sb8_exit(void)
{
snd_sb8_unregister_all();
}
module_init(alsa_card_sb8_init)
module_exit(alsa_card_sb8_exit)
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