[PATCH] remove cruel torture of macros and small furry animals in io-apic.c

From: Martin J. Bligh (mbligh@aracnet.com)
Date: Fri Jan 10 2003 - 19:54:26 EST


Andrew, sent to you because I figure it might appeal to you,
just based on a random gut feeling.

This removes the DO_ACTION stuff. The downside is that we add
some boring and repetive code. The upside is that it's simple,
and mere mortals can read it without screwing their brains into
a small piece of silly putty and bouncing it off the wall.
I think that's more important than pure source code size.

It also removes an unnecessary IO/apic read the code called
from balance_irq, which seems worthwhile.

I'd like to reformat the for loops into something more obvious
as well, but I'll let that one lie for now. This is tested on
a 16-way NUMA-Q.

diff -purN -X /home/mbligh/.diff.exclude virgin/arch/i386/kernel/io_apic.c doaction2/arch/i386/kernel/io_apic.c
--- virgin/arch/i386/kernel/io_apic.c Fri Dec 27 10:31:36 2002
+++ doaction2/arch/i386/kernel/io_apic.c Fri Jan 10 15:41:30 2003
@@ -116,40 +116,84 @@ static void __init replace_pin_at_irq(un
         }
 }
 
-#define __DO_ACTION(R, ACTION, FINAL) \
- \
-{ \
- 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 + R + pin*2); \
- reg ACTION; \
- io_apic_modify(entry->apic, 0x10 + R + pin*2, reg); \
- if (!entry->next) \
- break; \
- entry = irq_2_pin + entry->next; \
- } \
- FINAL; \
-}
-
-#define DO_ACTION(name,R,ACTION, FINAL) \
- \
- static void name##_IO_APIC_irq (unsigned int irq) \
- __DO_ACTION(R, ACTION, FINAL)
-
-DO_ACTION( __mask, 0, |= 0x00010000, io_apic_sync(entry->apic) )
- /* mask = 1 */
-DO_ACTION( __unmask, 0, &= 0xfffeffff, )
- /* mask = 0 */
-DO_ACTION( __mask_and_edge, 0, = (reg & 0xffff7fff) | 0x00010000, )
- /* mask = 1, trigger = 0 */
-DO_ACTION( __unmask_and_level, 0, = (reg & 0xfffeffff) | 0x00008000, )
- /* mask = 0, trigger = 1 */
+/* mask = 1 */
+static void __mask_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 |= 0x00010000);
+ if (!entry->next)
+ break;
+ entry = irq_2_pin + entry->next;
+ }
+ 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;
+ }
+}
+
+/* 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;
+ }
+}
+
+/* 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;
+ }
+}
 
 static void mask_IO_APIC_irq (unsigned int irq)
 {
@@ -197,13 +241,23 @@ static void clear_IO_APIC (void)
 static void set_ioapic_affinity (unsigned int irq, unsigned long mask)
 {
         unsigned long flags;
+ int pin;
+ struct irq_pin_list *entry = irq_2_pin + irq;
 
         /*
          * Only the first 8 bits are valid.
          */
         mask = mask << 24;
         spin_lock_irqsave(&ioapic_lock, flags);
- __DO_ACTION(1, = mask, )
+ for (;;) {
+ pin = entry->pin;
+ if (pin == -1)
+ break;
+ io_apic_modify(entry->apic, 0x10 + 1 + pin*2, mask);
+ if (!entry->next)
+ break;
+ entry = irq_2_pin + entry->next;
+ }
         spin_unlock_irqrestore(&ioapic_lock, flags);
 }
 

-
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