kernel-fxtec-pro1x/arch/powerpc/platforms/powermac/pfunc_base.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

410 lines
10 KiB
C

#include <linux/types.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <asm/pmac_feature.h>
#include <asm/pmac_pfunc.h>
#undef DEBUG
#ifdef DEBUG
#define DBG(fmt...) printk(fmt)
#else
#define DBG(fmt...)
#endif
static irqreturn_t macio_gpio_irq(int irq, void *data)
{
pmf_do_irq(data);
return IRQ_HANDLED;
}
static int macio_do_gpio_irq_enable(struct pmf_function *func)
{
unsigned int irq = irq_of_parse_and_map(func->node, 0);
if (irq == NO_IRQ)
return -EINVAL;
return request_irq(irq, macio_gpio_irq, 0, func->node->name, func);
}
static int macio_do_gpio_irq_disable(struct pmf_function *func)
{
unsigned int irq = irq_of_parse_and_map(func->node, 0);
if (irq == NO_IRQ)
return -EINVAL;
free_irq(irq, func);
return 0;
}
static int macio_do_gpio_write(PMF_STD_ARGS, u8 value, u8 mask)
{
u8 __iomem *addr = (u8 __iomem *)func->driver_data;
unsigned long flags;
u8 tmp;
/* Check polarity */
if (args && args->count && !args->u[0].v)
value = ~value;
/* Toggle the GPIO */
spin_lock_irqsave(&feature_lock, flags);
tmp = readb(addr);
tmp = (tmp & ~mask) | (value & mask);
DBG("Do write 0x%02x to GPIO %s (%p)\n",
tmp, func->node->full_name, addr);
writeb(tmp, addr);
spin_unlock_irqrestore(&feature_lock, flags);
return 0;
}
static int macio_do_gpio_read(PMF_STD_ARGS, u8 mask, int rshift, u8 xor)
{
u8 __iomem *addr = (u8 __iomem *)func->driver_data;
u32 value;
/* Check if we have room for reply */
if (args == NULL || args->count == 0 || args->u[0].p == NULL)
return -EINVAL;
value = readb(addr);
*args->u[0].p = ((value & mask) >> rshift) ^ xor;
return 0;
}
static int macio_do_delay(PMF_STD_ARGS, u32 duration)
{
/* assume we can sleep ! */
msleep((duration + 999) / 1000);
return 0;
}
static struct pmf_handlers macio_gpio_handlers = {
.irq_enable = macio_do_gpio_irq_enable,
.irq_disable = macio_do_gpio_irq_disable,
.write_gpio = macio_do_gpio_write,
.read_gpio = macio_do_gpio_read,
.delay = macio_do_delay,
};
static void macio_gpio_init_one(struct macio_chip *macio)
{
struct device_node *gparent, *gp;
/*
* Find the "gpio" parent node
*/
for (gparent = NULL;
(gparent = of_get_next_child(macio->of_node, gparent)) != NULL;)
if (strcmp(gparent->name, "gpio") == 0)
break;
if (gparent == NULL)
return;
DBG("Installing GPIO functions for macio %s\n",
macio->of_node->full_name);
/*
* Ok, got one, we dont need anything special to track them down, so
* we just create them all
*/
for (gp = NULL; (gp = of_get_next_child(gparent, gp)) != NULL;) {
const u32 *reg = get_property(gp, "reg", NULL);
unsigned long offset;
if (reg == NULL)
continue;
offset = *reg;
/* Deal with old style device-tree. We can safely hard code the
* offset for now too even if it's a bit gross ...
*/
if (offset < 0x50)
offset += 0x50;
offset += (unsigned long)macio->base;
pmf_register_driver(gp, &macio_gpio_handlers, (void *)offset);
}
DBG("Calling initial GPIO functions for macio %s\n",
macio->of_node->full_name);
/* And now we run all the init ones */
for (gp = NULL; (gp = of_get_next_child(gparent, gp)) != NULL;)
pmf_do_functions(gp, NULL, 0, PMF_FLAGS_ON_INIT, NULL);
/* Note: We do not at this point implement the "at sleep" or "at wake"
* functions. I yet to find any for GPIOs anyway
*/
}
static int macio_do_write_reg32(PMF_STD_ARGS, u32 offset, u32 value, u32 mask)
{
struct macio_chip *macio = func->driver_data;
unsigned long flags;
spin_lock_irqsave(&feature_lock, flags);
MACIO_OUT32(offset, (MACIO_IN32(offset) & ~mask) | (value & mask));
spin_unlock_irqrestore(&feature_lock, flags);
return 0;
}
static int macio_do_read_reg32(PMF_STD_ARGS, u32 offset)
{
struct macio_chip *macio = func->driver_data;
/* Check if we have room for reply */
if (args == NULL || args->count == 0 || args->u[0].p == NULL)
return -EINVAL;
*args->u[0].p = MACIO_IN32(offset);
return 0;
}
static int macio_do_write_reg8(PMF_STD_ARGS, u32 offset, u8 value, u8 mask)
{
struct macio_chip *macio = func->driver_data;
unsigned long flags;
spin_lock_irqsave(&feature_lock, flags);
MACIO_OUT8(offset, (MACIO_IN8(offset) & ~mask) | (value & mask));
spin_unlock_irqrestore(&feature_lock, flags);
return 0;
}
static int macio_do_read_reg8(PMF_STD_ARGS, u32 offset)
{
struct macio_chip *macio = func->driver_data;
/* Check if we have room for reply */
if (args == NULL || args->count == 0 || args->u[0].p == NULL)
return -EINVAL;
*((u8 *)(args->u[0].p)) = MACIO_IN8(offset);
return 0;
}
static int macio_do_read_reg32_msrx(PMF_STD_ARGS, u32 offset, u32 mask,
u32 shift, u32 xor)
{
struct macio_chip *macio = func->driver_data;
/* Check if we have room for reply */
if (args == NULL || args->count == 0 || args->u[0].p == NULL)
return -EINVAL;
*args->u[0].p = ((MACIO_IN32(offset) & mask) >> shift) ^ xor;
return 0;
}
static int macio_do_read_reg8_msrx(PMF_STD_ARGS, u32 offset, u32 mask,
u32 shift, u32 xor)
{
struct macio_chip *macio = func->driver_data;
/* Check if we have room for reply */
if (args == NULL || args->count == 0 || args->u[0].p == NULL)
return -EINVAL;
*((u8 *)(args->u[0].p)) = ((MACIO_IN8(offset) & mask) >> shift) ^ xor;
return 0;
}
static int macio_do_write_reg32_slm(PMF_STD_ARGS, u32 offset, u32 shift,
u32 mask)
{
struct macio_chip *macio = func->driver_data;
unsigned long flags;
u32 tmp, val;
/* Check args */
if (args == NULL || args->count == 0)
return -EINVAL;
spin_lock_irqsave(&feature_lock, flags);
tmp = MACIO_IN32(offset);
val = args->u[0].v << shift;
tmp = (tmp & ~mask) | (val & mask);
MACIO_OUT32(offset, tmp);
spin_unlock_irqrestore(&feature_lock, flags);
return 0;
}
static int macio_do_write_reg8_slm(PMF_STD_ARGS, u32 offset, u32 shift,
u32 mask)
{
struct macio_chip *macio = func->driver_data;
unsigned long flags;
u32 tmp, val;
/* Check args */
if (args == NULL || args->count == 0)
return -EINVAL;
spin_lock_irqsave(&feature_lock, flags);
tmp = MACIO_IN8(offset);
val = args->u[0].v << shift;
tmp = (tmp & ~mask) | (val & mask);
MACIO_OUT8(offset, tmp);
spin_unlock_irqrestore(&feature_lock, flags);
return 0;
}
static struct pmf_handlers macio_mmio_handlers = {
.write_reg32 = macio_do_write_reg32,
.read_reg32 = macio_do_read_reg32,
.write_reg8 = macio_do_write_reg8,
.read_reg8 = macio_do_read_reg8,
.read_reg32_msrx = macio_do_read_reg32_msrx,
.read_reg8_msrx = macio_do_read_reg8_msrx,
.write_reg32_slm = macio_do_write_reg32_slm,
.write_reg8_slm = macio_do_write_reg8_slm,
.delay = macio_do_delay,
};
static void macio_mmio_init_one(struct macio_chip *macio)
{
DBG("Installing MMIO functions for macio %s\n",
macio->of_node->full_name);
pmf_register_driver(macio->of_node, &macio_mmio_handlers, macio);
}
static struct device_node *unin_hwclock;
static int unin_do_write_reg32(PMF_STD_ARGS, u32 offset, u32 value, u32 mask)
{
unsigned long flags;
spin_lock_irqsave(&feature_lock, flags);
/* This is fairly bogus in darwin, but it should work for our needs
* implemeted that way:
*/
UN_OUT(offset, (UN_IN(offset) & ~mask) | (value & mask));
spin_unlock_irqrestore(&feature_lock, flags);
return 0;
}
static struct pmf_handlers unin_mmio_handlers = {
.write_reg32 = unin_do_write_reg32,
.delay = macio_do_delay,
};
static void uninorth_install_pfunc(void)
{
struct device_node *np;
DBG("Installing functions for UniN %s\n",
uninorth_node->full_name);
/*
* Install handlers for the bridge itself
*/
pmf_register_driver(uninorth_node, &unin_mmio_handlers, NULL);
pmf_do_functions(uninorth_node, NULL, 0, PMF_FLAGS_ON_INIT, NULL);
/*
* Install handlers for the hwclock child if any
*/
for (np = NULL; (np = of_get_next_child(uninorth_node, np)) != NULL;)
if (strcmp(np->name, "hw-clock") == 0) {
unin_hwclock = np;
break;
}
if (unin_hwclock) {
DBG("Installing functions for UniN clock %s\n",
unin_hwclock->full_name);
pmf_register_driver(unin_hwclock, &unin_mmio_handlers, NULL);
pmf_do_functions(unin_hwclock, NULL, 0, PMF_FLAGS_ON_INIT,
NULL);
}
}
/* We export this as the SMP code might init us early */
int __init pmac_pfunc_base_install(void)
{
static int pfbase_inited;
int i;
if (pfbase_inited)
return 0;
pfbase_inited = 1;
if (!machine_is(powermac))
return 0;
DBG("Installing base platform functions...\n");
/*
* Locate mac-io chips and install handlers
*/
for (i = 0 ; i < MAX_MACIO_CHIPS; i++) {
if (macio_chips[i].of_node) {
macio_mmio_init_one(&macio_chips[i]);
macio_gpio_init_one(&macio_chips[i]);
}
}
/*
* Install handlers for northbridge and direct mapped hwclock
* if any. We do not implement the config space access callback
* which is only ever used for functions that we do not call in
* the current driver (enabling/disabling cells in U2, mostly used
* to restore the PCI settings, we do that differently)
*/
if (uninorth_node && uninorth_base)
uninorth_install_pfunc();
DBG("All base functions installed\n");
return 0;
}
arch_initcall(pmac_pfunc_base_install);
#ifdef CONFIG_PM
/* Those can be called by pmac_feature. Ultimately, I should use a sysdev
* or a device, but for now, that's good enough until I sort out some
* ordering issues. Also, we do not bother with GPIOs, as so far I yet have
* to see a case where a GPIO function has the on-suspend or on-resume bit
*/
void pmac_pfunc_base_suspend(void)
{
int i;
for (i = 0 ; i < MAX_MACIO_CHIPS; i++) {
if (macio_chips[i].of_node)
pmf_do_functions(macio_chips[i].of_node, NULL, 0,
PMF_FLAGS_ON_SLEEP, NULL);
}
if (uninorth_node)
pmf_do_functions(uninorth_node, NULL, 0,
PMF_FLAGS_ON_SLEEP, NULL);
if (unin_hwclock)
pmf_do_functions(unin_hwclock, NULL, 0,
PMF_FLAGS_ON_SLEEP, NULL);
}
void pmac_pfunc_base_resume(void)
{
int i;
if (unin_hwclock)
pmf_do_functions(unin_hwclock, NULL, 0,
PMF_FLAGS_ON_WAKE, NULL);
if (uninorth_node)
pmf_do_functions(uninorth_node, NULL, 0,
PMF_FLAGS_ON_WAKE, NULL);
for (i = 0 ; i < MAX_MACIO_CHIPS; i++) {
if (macio_chips[i].of_node)
pmf_do_functions(macio_chips[i].of_node, NULL, 0,
PMF_FLAGS_ON_WAKE, NULL);
}
}
#endif /* CONFIG_PM */