[patch 01/46] Add irq flag to disable balancing for an interrupt

Thomas Gleixner
2007-01-23T22:00:43Z

[-- Attachment #1: genirq-add-noirqbalance-flag.patch --]
[-- Type: text/plain, Size: 6442 bytes --]

From: Thomas Gleixner <tglx@linutronix.de>

Add a flag so we can prevent the irq balancing of an interrupt. Move
the bits, so we have room for more :)

Necessary for the ability to setup clocksources more flexible (e.g. use
the different HPET channels per CPU)

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

---
arch/i386/kernel/io_apic.c | 4 ++--
include/linux/interrupt.h | 3 +++
include/linux/irq.h | 40 ++++++++++++++++++++++++----------------
kernel/irq/manage.c | 4 ++++
kernel/irq/proc.c | 2 +-
5 files changed, 34 insertions(+), 19 deletions(-)

Index: linux-2.6.20-rc4-mm1-bo/arch/i386/kernel/io_apic.c
===================================================================
--- linux-2.6.20-rc4-mm1-bo.orig/arch/i386/kernel/io_apic.c
+++ linux-2.6.20-rc4-mm1-bo/arch/i386/kernel/io_apic.c
@@ -482,8 +482,8 @@ static void do_irq_balance(void)
package_index = CPU_TO_PACKAGEINDEX(i);
for (j = 0; j < NR_IRQS; j++) {
unsigned long value_now, delta;
- /* Is this an active IRQ? */
- if (!irq_desc[j].action)
+ /* Is this an active IRQ or balancing disabled ? */
+ if (!irq_desc[j].action || irq_balancing_disabled(j))
continue;
if ( package_index == i )
IRQ_DELTA(package_index,j) = 0;
Index: linux-2.6.20-rc4-mm1-bo/include/linux/interrupt.h
===================================================================
--- linux-2.6.20-rc4-mm1-bo.orig/include/linux/interrupt.h
+++ linux-2.6.20-rc4-mm1-bo/include/linux/interrupt.h
@@ -41,6 +41,8 @@
* IRQF_SHARED - allow sharing the irq among several devices
* IRQF_PROBE_SHARED - set by callers when they expect sharing mismatches to occur
* IRQF_TIMER - Flag to mark this interrupt as timer interrupt
+ * IRQF_PERCPU - Interrupt is per cpu
+ * IRQF_NOBALANCING - Flag to exclude this interrupt from irq balancing
*/
#define IRQF_DISABLED 0x00000020
#define IRQF_SAMPLE_RANDOM 0x00000040
@@ -48,6 +50,7 @@
#define IRQF_PROBE_SHARED 0x00000100
#define IRQF_TIMER 0x00000200
#define IRQF_PERCPU 0x00000400
+#define IRQF_NOBALANCING 0x00000800

typedef irqreturn_t (*irq_handler_t)(int, void *);

Index: linux-2.6.20-rc4-mm1-bo/include/linux/irq.h
===================================================================
--- linux-2.6.20-rc4-mm1-bo.orig/include/linux/irq.h
+++ linux-2.6.20-rc4-mm1-bo/include/linux/irq.h
@@ -31,7 +31,7 @@ typedef void fastcall (*irq_flow_handler
/*
* IRQ line status.
*
- * Bits 0-16 are reserved for the IRQF_* bits in linux/interrupt.h
+ * Bits 0-7 are reserved for the IRQF_* bits in linux/interrupt.h
*
* IRQ types
*/
@@ -45,27 +45,35 @@ typedef void fastcall (*irq_flow_handler
#define IRQ_TYPE_PROBE 0x00000010 /* Probing in progress */

/* Internal flags */
-#define IRQ_INPROGRESS 0x00010000 /* IRQ handler active - do not enter! */
-#define IRQ_DISABLED 0x00020000 /* IRQ disabled - do not enter! */
-#define IRQ_PENDING 0x00040000 /* IRQ pending - replay on enable */
-#define IRQ_REPLAY 0x00080000 /* IRQ has been replayed but not acked yet */
-#define IRQ_AUTODETECT 0x00100000 /* IRQ is being autodetected */
-#define IRQ_WAITING 0x00200000 /* IRQ not yet seen - for autodetection */
-#define IRQ_LEVEL 0x00400000 /* IRQ level triggered */
-#define IRQ_MASKED 0x00800000 /* IRQ masked - shouldn't be seen again */
-#define IRQ_PER_CPU 0x01000000 /* IRQ is per CPU */
+#define IRQ_INPROGRESS 0x00000100 /* IRQ handler active - do not enter! */
+#define IRQ_DISABLED 0x00000200 /* IRQ disabled - do not enter! */
+#define IRQ_PENDING 0x00000400 /* IRQ pending - replay on enable */
+#define IRQ_REPLAY 0x00000800 /* IRQ has been replayed but not acked yet */
+#define IRQ_AUTODETECT 0x00001000 /* IRQ is being autodetected */
+#define IRQ_WAITING 0x00002000 /* IRQ not yet seen - for autodetection */
+#define IRQ_LEVEL 0x00004000 /* IRQ level triggered */
+#define IRQ_MASKED 0x00008000 /* IRQ masked - shouldn't be seen again */
+#define IRQ_PER_CPU 0x00010000 /* IRQ is per CPU */
+#define IRQ_NOPROBE 0x00020000 /* IRQ is not valid for probing */
+#define IRQ_NOREQUEST 0x00040000 /* IRQ cannot be requested */
+#define IRQ_NOAUTOEN 0x00080000 /* IRQ will not be enabled on request irq */
+#define IRQ_DELAYED_DISABLE 0x00100000 /* IRQ disable (masking) happens delayed. */
+#define IRQ_WAKEUP 0x00200000 /* IRQ triggers system wakeup */
+#define IRQ_MOVE_PENDING 0x00400000 /* need to re-target IRQ destination */
+#define IRQ_NO_BALANCING 0x00800000 /* IRQ is excluded from balancing */
+
#ifdef CONFIG_IRQ_PER_CPU
# define CHECK_IRQ_PER_CPU(var) ((var) & IRQ_PER_CPU)
+# define IRQ_NO_BALANCING_MASK (IRQ_PER_CPU | IRQ_NO_BALANCING)
#else
# define CHECK_IRQ_PER_CPU(var) 0
+# define IRQ_NO_BALANCING_MASK IRQ_NO_BALANCING
#endif

-#define IRQ_NOPROBE 0x02000000 /* IRQ is not valid for probing */
-#define IRQ_NOREQUEST 0x04000000 /* IRQ cannot be requested */
-#define IRQ_NOAUTOEN 0x08000000 /* IRQ will not be enabled on request irq */
-#define IRQ_DELAYED_DISABLE 0x10000000 /* IRQ disable (masking) happens delayed. */
-#define IRQ_WAKEUP 0x20000000 /* IRQ triggers system wakeup */
-#define IRQ_MOVE_PENDING 0x40000000 /* need to re-target IRQ destination */
+static inline int irq_balancing_disabled(unsigned int irq)
+{
+ return irq_desc[irq].status & IRQ_NO_BALANCING_MASK;
+}

struct proc_dir_entry;

Index: linux-2.6.20-rc4-mm1-bo/kernel/irq/manage.c
===================================================================
--- linux-2.6.20-rc4-mm1-bo.orig/kernel/irq/manage.c
+++ linux-2.6.20-rc4-mm1-bo/kernel/irq/manage.c
@@ -281,6 +281,10 @@ int setup_irq(unsigned int irq, struct i
if (new->flags & IRQF_PERCPU)
desc->status |= IRQ_PER_CPU;
#endif
+ /* Exclude IRQ from balancing */
+ if (new->flags & IRQF_NOBALANCING)
+ desc->status |= IRQ_NO_BALANCING;
+
if (!shared) {
irq_chip_set_defaults(desc->chip);

Index: linux-2.6.20-rc4-mm1-bo/kernel/irq/proc.c
===================================================================
--- linux-2.6.20-rc4-mm1-bo.orig/kernel/irq/proc.c
+++ linux-2.6.20-rc4-mm1-bo/kernel/irq/proc.c
@@ -55,7 +55,7 @@ static int irq_affinity_write_proc(struc
cpumask_t new_value, tmp;

if (!irq_desc[irq].chip->set_affinity || no_irq_affinity ||
- CHECK_IRQ_PER_CPU(irq_desc[irq].status))
+ irq_balancing_disabled(irq))
return -EIO;

err = cpumask_parse_user(buffer, count, new_value);

--