Re: Cleanups for APIC

From: Ingo Molnar
Date: Thu May 27 2004 - 08:16:18 EST



On Tue, 25 May 2004, Pavel Machek wrote:

> This cleans up io_apic.c a bit -- I do not really like 4 copies of same
> code. Does it look okay to apply?

yeah, agreed - i checked & test it, it's ok. I made a small modification
(see the patch below) to uninline the __modify_IO_APIC_irq() function -
shaving 0.5K off the kernel's size ...

(wrt. io_apic_sync(): i added it in 2.1.104 together with some other
changes - i dont this it's necessary anymore - the local APICs had
writearound erratas, but i dont remember this ever being necessary for
IO-APICs. I'll address this in another patch.)

Ingo

From: Pavel Machek <pavel@xxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>

--- linux/arch/i386/kernel/io_apic.c.orig
+++ linux/arch/i386/kernel/io_apic.c
@@ -41,8 +41,6 @@

#include "io_ports.h"

-#undef APIC_LOCKUP_DEBUG
-
#define APIC_LOCKUP_DEBUG

static spinlock_t ioapic_lock = SPIN_LOCK_UNLOCKED;
@@ -127,83 +125,50 @@ static void __init replace_pin_at_irq(un
}
}

-/* mask = 1 */
-static void __mask_IO_APIC_irq (unsigned int irq)
+static void __modify_IO_APIC_irq (unsigned int irq, unsigned long enable, unsigned long disable)
{
- int pin;
struct irq_pin_list *entry = irq_2_pin + irq;
+ unsigned int pin, reg;

for (;;) {
- unsigned int reg;
pin = entry->pin;
if (pin == -1)
break;
reg = io_apic_read(entry->apic, 0x10 + pin*2);
- io_apic_modify(entry->apic, 0x10 + pin*2, reg |= 0x00010000);
+ reg &= ~disable;
+ reg |= enable;
+ io_apic_modify(entry->apic, 0x10 + pin*2, reg);
if (!entry->next)
break;
entry = irq_2_pin + entry->next;
}
+}
+
+/* mask = 1 */
+static void __mask_IO_APIC_irq (unsigned int irq)
+{
+ struct irq_pin_list *entry = irq_2_pin + irq;
+ __modify_IO_APIC_irq(irq, 0x00010000, 0);
+ /* Is it needed? Or do others need it too? */
io_apic_sync(entry->apic);
}

/* mask = 0 */
static void __unmask_IO_APIC_irq (unsigned int irq)
{
- int pin;
- struct irq_pin_list *entry = irq_2_pin + irq;
-
- for (;;) {
- unsigned int reg;
- pin = entry->pin;
- if (pin == -1)
- break;
- reg = io_apic_read(entry->apic, 0x10 + pin*2);
- io_apic_modify(entry->apic, 0x10 + pin*2, reg &= 0xfffeffff);
- if (!entry->next)
- break;
- entry = irq_2_pin + entry->next;
- }
+ __modify_IO_APIC_irq(irq, 0, 0x00010000);
}

/* mask = 1, trigger = 0 */
static void __mask_and_edge_IO_APIC_irq (unsigned int irq)
{
- int pin;
- struct irq_pin_list *entry = irq_2_pin + irq;
-
- for (;;) {
- unsigned int reg;
- pin = entry->pin;
- if (pin == -1)
- break;
- reg = io_apic_read(entry->apic, 0x10 + pin*2);
- reg = (reg & 0xffff7fff) | 0x00010000;
- io_apic_modify(entry->apic, 0x10 + pin*2, reg);
- if (!entry->next)
- break;
- entry = irq_2_pin + entry->next;
- }
+ __modify_IO_APIC_irq(irq, 0x00010000, 0x00008000);
}

/* mask = 0, trigger = 1 */
static void __unmask_and_level_IO_APIC_irq (unsigned int irq)
{
- int pin;
- struct irq_pin_list *entry = irq_2_pin + irq;
-
- for (;;) {
- unsigned int reg;
- pin = entry->pin;
- if (pin == -1)
- break;
- reg = io_apic_read(entry->apic, 0x10 + pin*2);
- reg = (reg & 0xfffeffff) | 0x00008000;
- io_apic_modify(entry->apic, 0x10 + pin*2, reg);
- if (!entry->next)
- break;
- entry = irq_2_pin + entry->next;
- }
+ __modify_IO_APIC_irq(irq, 0x00008000, 0x00010000);
}

static void mask_IO_APIC_irq (unsigned int irq)
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/