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linux/sound/oss/dmasound/dmasound_q40.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

635 lines
14 KiB
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/*
* linux/sound/oss/dmasound/dmasound_q40.c
*
* Q40 DMA Sound Driver
*
* See linux/sound/oss/dmasound/dmasound_core.c for copyright and credits
* prior to 28/01/2001
*
* 28/01/2001 [0.1] Iain Sandoe
* - added versioning
* - put in and populated the hardware_afmts field.
* [0.2] - put in SNDCTL_DSP_GETCAPS value.
* [0.3] - put in default hard/soft settings.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/soundcard.h>
#include <linux/interrupt.h>
#include <asm/uaccess.h>
#include <asm/q40ints.h>
#include <asm/q40_master.h>
#include "dmasound.h"
#define DMASOUND_Q40_REVISION 0
#define DMASOUND_Q40_EDITION 3
static int expand_bal; /* Balance factor for expanding (not volume!) */
static int expand_data; /* Data for expanding */
/*** Low level stuff *********************************************************/
static void *Q40Alloc(unsigned int size, gfp_t flags);
static void Q40Free(void *, unsigned int);
static int Q40IrqInit(void);
#ifdef MODULE
static void Q40IrqCleanUp(void);
#endif
static void Q40Silence(void);
static void Q40Init(void);
static int Q40SetFormat(int format);
static int Q40SetVolume(int volume);
static void Q40PlayNextFrame(int index);
static void Q40Play(void);
static irqreturn_t Q40StereoInterrupt(int irq, void *dummy);
static irqreturn_t Q40MonoInterrupt(int irq, void *dummy);
static void Q40Interrupt(void);
/*** Mid level stuff *********************************************************/
/* userCount, frameUsed, frameLeft == byte counts */
static ssize_t q40_ct_law(const u_char __user *userPtr, size_t userCount,
u_char frame[], ssize_t *frameUsed,
ssize_t frameLeft)
{
char *table = dmasound.soft.format == AFMT_MU_LAW ? dmasound_ulaw2dma8: dmasound_alaw2dma8;
ssize_t count, used;
u_char *p = (u_char *) &frame[*frameUsed];
used = count = min_t(size_t, userCount, frameLeft);
if (copy_from_user(p,userPtr,count))
return -EFAULT;
while (count > 0) {
*p = table[*p]+128;
p++;
count--;
}
*frameUsed += used ;
return used;
}
static ssize_t q40_ct_s8(const u_char __user *userPtr, size_t userCount,
u_char frame[], ssize_t *frameUsed,
ssize_t frameLeft)
{
ssize_t count, used;
u_char *p = (u_char *) &frame[*frameUsed];
used = count = min_t(size_t, userCount, frameLeft);
if (copy_from_user(p,userPtr,count))
return -EFAULT;
while (count > 0) {
*p = *p + 128;
p++;
count--;
}
*frameUsed += used;
return used;
}
static ssize_t q40_ct_u8(const u_char __user *userPtr, size_t userCount,
u_char frame[], ssize_t *frameUsed,
ssize_t frameLeft)
{
ssize_t count, used;
u_char *p = (u_char *) &frame[*frameUsed];
used = count = min_t(size_t, userCount, frameLeft);
if (copy_from_user(p,userPtr,count))
return -EFAULT;
*frameUsed += used;
return used;
}
/* a bit too complicated to optimise right now ..*/
static ssize_t q40_ctx_law(const u_char __user *userPtr, size_t userCount,
u_char frame[], ssize_t *frameUsed,
ssize_t frameLeft)
{
unsigned char *table = (unsigned char *)
(dmasound.soft.format == AFMT_MU_LAW ? dmasound_ulaw2dma8: dmasound_alaw2dma8);
unsigned int data = expand_data;
u_char *p = (u_char *) &frame[*frameUsed];
int bal = expand_bal;
int hSpeed = dmasound.hard.speed, sSpeed = dmasound.soft.speed;
int utotal, ftotal;
ftotal = frameLeft;
utotal = userCount;
while (frameLeft) {
u_char c;
if (bal < 0) {
if (userCount == 0)
break;
if (get_user(c, userPtr++))
return -EFAULT;
data = table[c];
data += 0x80;
userCount--;
bal += hSpeed;
}
*p++ = data;
frameLeft--;
bal -= sSpeed;
}
expand_bal = bal;
expand_data = data;
*frameUsed += (ftotal - frameLeft);
utotal -= userCount;
return utotal;
}
static ssize_t q40_ctx_s8(const u_char __user *userPtr, size_t userCount,
u_char frame[], ssize_t *frameUsed,
ssize_t frameLeft)
{
u_char *p = (u_char *) &frame[*frameUsed];
unsigned int data = expand_data;
int bal = expand_bal;
int hSpeed = dmasound.hard.speed, sSpeed = dmasound.soft.speed;
int utotal, ftotal;
ftotal = frameLeft;
utotal = userCount;
while (frameLeft) {
u_char c;
if (bal < 0) {
if (userCount == 0)
break;
if (get_user(c, userPtr++))
return -EFAULT;
data = c ;
data += 0x80;
userCount--;
bal += hSpeed;
}
*p++ = data;
frameLeft--;
bal -= sSpeed;
}
expand_bal = bal;
expand_data = data;
*frameUsed += (ftotal - frameLeft);
utotal -= userCount;
return utotal;
}
static ssize_t q40_ctx_u8(const u_char __user *userPtr, size_t userCount,
u_char frame[], ssize_t *frameUsed,
ssize_t frameLeft)
{
u_char *p = (u_char *) &frame[*frameUsed];
unsigned int data = expand_data;
int bal = expand_bal;
int hSpeed = dmasound.hard.speed, sSpeed = dmasound.soft.speed;
int utotal, ftotal;
ftotal = frameLeft;
utotal = userCount;
while (frameLeft) {
u_char c;
if (bal < 0) {
if (userCount == 0)
break;
if (get_user(c, userPtr++))
return -EFAULT;
data = c ;
userCount--;
bal += hSpeed;
}
*p++ = data;
frameLeft--;
bal -= sSpeed;
}
expand_bal = bal;
expand_data = data;
*frameUsed += (ftotal - frameLeft) ;
utotal -= userCount;
return utotal;
}
/* compressing versions */
static ssize_t q40_ctc_law(const u_char __user *userPtr, size_t userCount,
u_char frame[], ssize_t *frameUsed,
ssize_t frameLeft)
{
unsigned char *table = (unsigned char *)
(dmasound.soft.format == AFMT_MU_LAW ? dmasound_ulaw2dma8: dmasound_alaw2dma8);
unsigned int data = expand_data;
u_char *p = (u_char *) &frame[*frameUsed];
int bal = expand_bal;
int hSpeed = dmasound.hard.speed, sSpeed = dmasound.soft.speed;
int utotal, ftotal;
ftotal = frameLeft;
utotal = userCount;
while (frameLeft) {
u_char c;
while(bal<0) {
if (userCount == 0)
goto lout;
if (!(bal<(-hSpeed))) {
if (get_user(c, userPtr))
return -EFAULT;
data = 0x80 + table[c];
}
userPtr++;
userCount--;
bal += hSpeed;
}
*p++ = data;
frameLeft--;
bal -= sSpeed;
}
lout:
expand_bal = bal;
expand_data = data;
*frameUsed += (ftotal - frameLeft);
utotal -= userCount;
return utotal;
}
static ssize_t q40_ctc_s8(const u_char __user *userPtr, size_t userCount,
u_char frame[], ssize_t *frameUsed,
ssize_t frameLeft)
{
u_char *p = (u_char *) &frame[*frameUsed];
unsigned int data = expand_data;
int bal = expand_bal;
int hSpeed = dmasound.hard.speed, sSpeed = dmasound.soft.speed;
int utotal, ftotal;
ftotal = frameLeft;
utotal = userCount;
while (frameLeft) {
u_char c;
while (bal < 0) {
if (userCount == 0)
goto lout;
if (!(bal<(-hSpeed))) {
if (get_user(c, userPtr))
return -EFAULT;
data = c + 0x80;
}
userPtr++;
userCount--;
bal += hSpeed;
}
*p++ = data;
frameLeft--;
bal -= sSpeed;
}
lout:
expand_bal = bal;
expand_data = data;
*frameUsed += (ftotal - frameLeft);
utotal -= userCount;
return utotal;
}
static ssize_t q40_ctc_u8(const u_char __user *userPtr, size_t userCount,
u_char frame[], ssize_t *frameUsed,
ssize_t frameLeft)
{
u_char *p = (u_char *) &frame[*frameUsed];
unsigned int data = expand_data;
int bal = expand_bal;
int hSpeed = dmasound.hard.speed, sSpeed = dmasound.soft.speed;
int utotal, ftotal;
ftotal = frameLeft;
utotal = userCount;
while (frameLeft) {
u_char c;
while (bal < 0) {
if (userCount == 0)
goto lout;
if (!(bal<(-hSpeed))) {
if (get_user(c, userPtr))
return -EFAULT;
data = c ;
}
userPtr++;
userCount--;
bal += hSpeed;
}
*p++ = data;
frameLeft--;
bal -= sSpeed;
}
lout:
expand_bal = bal;
expand_data = data;
*frameUsed += (ftotal - frameLeft) ;
utotal -= userCount;
return utotal;
}
static TRANS transQ40Normal = {
q40_ct_law, q40_ct_law, q40_ct_s8, q40_ct_u8, NULL, NULL, NULL, NULL
};
static TRANS transQ40Expanding = {
q40_ctx_law, q40_ctx_law, q40_ctx_s8, q40_ctx_u8, NULL, NULL, NULL, NULL
};
static TRANS transQ40Compressing = {
q40_ctc_law, q40_ctc_law, q40_ctc_s8, q40_ctc_u8, NULL, NULL, NULL, NULL
};
/*** Low level stuff *********************************************************/
static void *Q40Alloc(unsigned int size, gfp_t flags)
{
return kmalloc(size, flags); /* change to vmalloc */
}
static void Q40Free(void *ptr, unsigned int size)
{
kfree(ptr);
}
static int __init Q40IrqInit(void)
{
/* Register interrupt handler. */
request_irq(Q40_IRQ_SAMPLE, Q40StereoInterrupt, 0,
"DMA sound", Q40Interrupt);
return(1);
}
#ifdef MODULE
static void Q40IrqCleanUp(void)
{
master_outb(0,SAMPLE_ENABLE_REG);
free_irq(Q40_IRQ_SAMPLE, Q40Interrupt);
}
#endif /* MODULE */
static void Q40Silence(void)
{
master_outb(0,SAMPLE_ENABLE_REG);
*DAC_LEFT=*DAC_RIGHT=127;
}
static char *q40_pp;
static unsigned int q40_sc;
static void Q40PlayNextFrame(int index)
{
u_char *start;
u_long size;
u_char speed;
/* used by Q40Play() if all doubts whether there really is something
* to be played are already wiped out.
*/
start = write_sq.buffers[write_sq.front];
size = (write_sq.count == index ? write_sq.rear_size : write_sq.block_size);
q40_pp=start;
q40_sc=size;
write_sq.front = (write_sq.front+1) % write_sq.max_count;
write_sq.active++;
speed=(dmasound.hard.speed==10000 ? 0 : 1);
master_outb( 0,SAMPLE_ENABLE_REG);
free_irq(Q40_IRQ_SAMPLE, Q40Interrupt);
if (dmasound.soft.stereo)
request_irq(Q40_IRQ_SAMPLE, Q40StereoInterrupt, 0,
"Q40 sound", Q40Interrupt);
else
request_irq(Q40_IRQ_SAMPLE, Q40MonoInterrupt, 0,
"Q40 sound", Q40Interrupt);
master_outb( speed, SAMPLE_RATE_REG);
master_outb( 1,SAMPLE_CLEAR_REG);
master_outb( 1,SAMPLE_ENABLE_REG);
}
static void Q40Play(void)
{
unsigned long flags;
if (write_sq.active || write_sq.count<=0 ) {
/* There's already a frame loaded */
return;
}
/* nothing in the queue */
if (write_sq.count <= 1 && write_sq.rear_size < write_sq.block_size && !write_sq.syncing) {
/* hmmm, the only existing frame is not
* yet filled and we're not syncing?
*/
return;
}
spin_lock_irqsave(&dmasound.lock, flags);
Q40PlayNextFrame(1);
spin_unlock_irqrestore(&dmasound.lock, flags);
}
static irqreturn_t Q40StereoInterrupt(int irq, void *dummy)
{
spin_lock(&dmasound.lock);
if (q40_sc>1){
*DAC_LEFT=*q40_pp++;
*DAC_RIGHT=*q40_pp++;
q40_sc -=2;
master_outb(1,SAMPLE_CLEAR_REG);
}else Q40Interrupt();
spin_unlock(&dmasound.lock);
return IRQ_HANDLED;
}
static irqreturn_t Q40MonoInterrupt(int irq, void *dummy)
{
spin_lock(&dmasound.lock);
if (q40_sc>0){
*DAC_LEFT=*q40_pp;
*DAC_RIGHT=*q40_pp++;
q40_sc --;
master_outb(1,SAMPLE_CLEAR_REG);
}else Q40Interrupt();
spin_unlock(&dmasound.lock);
return IRQ_HANDLED;
}
static void Q40Interrupt(void)
{
if (!write_sq.active) {
/* playing was interrupted and sq_reset() has already cleared
* the sq variables, so better don't do anything here.
*/
WAKE_UP(write_sq.sync_queue);
master_outb(0,SAMPLE_ENABLE_REG); /* better safe */
goto exit;
} else write_sq.active=0;
write_sq.count--;
Q40Play();
if (q40_sc<2)
{ /* there was nothing to play, disable irq */
master_outb(0,SAMPLE_ENABLE_REG);
*DAC_LEFT=*DAC_RIGHT=127;
}
WAKE_UP(write_sq.action_queue);
exit:
master_outb(1,SAMPLE_CLEAR_REG);
}
static void Q40Init(void)
{
int i, idx;
const int freq[] = {10000, 20000};
/* search a frequency that fits into the allowed error range */
idx = -1;
for (i = 0; i < 2; i++)
if ((100 * abs(dmasound.soft.speed - freq[i]) / freq[i]) <= catchRadius)
idx = i;
dmasound.hard = dmasound.soft;
/*sound.hard.stereo=1;*/ /* no longer true */
dmasound.hard.size=8;
if (idx > -1) {
dmasound.soft.speed = freq[idx];
dmasound.trans_write = &transQ40Normal;
} else
dmasound.trans_write = &transQ40Expanding;
Q40Silence();
if (dmasound.hard.speed > 20200) {
/* squeeze the sound, we do that */
dmasound.hard.speed = 20000;
dmasound.trans_write = &transQ40Compressing;
} else if (dmasound.hard.speed > 10000) {
dmasound.hard.speed = 20000;
} else {
dmasound.hard.speed = 10000;
}
expand_bal = -dmasound.soft.speed;
}
static int Q40SetFormat(int format)
{
/* Q40 sound supports only 8bit modes */
switch (format) {
case AFMT_QUERY:
return(dmasound.soft.format);
case AFMT_MU_LAW:
case AFMT_A_LAW:
case AFMT_S8:
case AFMT_U8:
break;
default:
format = AFMT_S8;
}
dmasound.soft.format = format;
dmasound.soft.size = 8;
if (dmasound.minDev == SND_DEV_DSP) {
dmasound.dsp.format = format;
dmasound.dsp.size = 8;
}
Q40Init();
return(format);
}
static int Q40SetVolume(int volume)
{
return 0;
}
/*** Machine definitions *****************************************************/
static SETTINGS def_hard = {
.format = AFMT_U8,
.stereo = 0,
.size = 8,
.speed = 10000
} ;
static SETTINGS def_soft = {
.format = AFMT_U8,
.stereo = 0,
.size = 8,
.speed = 8000
} ;
static MACHINE machQ40 = {
.name = "Q40",
.name2 = "Q40",
.owner = THIS_MODULE,
.dma_alloc = Q40Alloc,
.dma_free = Q40Free,
.irqinit = Q40IrqInit,
#ifdef MODULE
.irqcleanup = Q40IrqCleanUp,
#endif /* MODULE */
.init = Q40Init,
.silence = Q40Silence,
.setFormat = Q40SetFormat,
.setVolume = Q40SetVolume,
.play = Q40Play,
.min_dsp_speed = 10000,
.version = ((DMASOUND_Q40_REVISION<<8) | DMASOUND_Q40_EDITION),
.hardware_afmts = AFMT_U8, /* h'ware-supported formats *only* here */
.capabilities = DSP_CAP_BATCH /* As per SNDCTL_DSP_GETCAPS */
};
/*** Config & Setup **********************************************************/
int __init dmasound_q40_init(void)
{
if (MACH_IS_Q40) {
dmasound.mach = machQ40;
dmasound.mach.default_hard = def_hard ;
dmasound.mach.default_soft = def_soft ;
return dmasound_init();
} else
return -ENODEV;
}
static void __exit dmasound_q40_cleanup(void)
{
dmasound_deinit();
}
module_init(dmasound_q40_init);
module_exit(dmasound_q40_cleanup);
MODULE_DESCRIPTION("Q40/Q60 sound driver");
MODULE_LICENSE("GPL");
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