Re: IO-APIC + timer doesn't work

From: Yinghai Lu
Date: Wed Dec 20 2006 - 01:51:16 EST


On 12/19/06, Eric W. Biederman <ebiederm@xxxxxxxxxxxx> wrote:
So the pin2 case should be tested right after the pin1 case as we do
currently. On most new boards that will be a complete noop.

But it is better than our current blind guess at using ExtINT mode.

I figure after we try what the BIOS has told us about and that
has failed we should first try the common irq 0 apic mappings,
and then try the common ExtINT mappings.

Please check if this one is ok. [PATCH] x86_64: check_timer with io apic setup before try_apic_pin

add io apic setup before try_apic_pin

cc: Andi Kleen <ak@xxxxxxx>
cc: Eric W. Biederman <ebiederm@xxxxxxxxxxxx>
Signed-off-by: Yinghai Lu <yinghai.lu@xxxxxxx>

diff --git a/arch/x86_64/kernel/io_apic.c b/arch/x86_64/kernel/io_apic.c
index 2a1dcd5..6d09fc0 100644
--- a/arch/x86_64/kernel/io_apic.c
+++ b/arch/x86_64/kernel/io_apic.c
@@ -273,10 +273,17 @@ static void add_pin_to_irq(unsigned int irq, int apic, int pin)
struct irq_pin_list *entry = irq_2_pin + irq;

BUG_ON(irq >= NR_IRQS);
- while (entry->next)
+ while (entry->next) {
+ if (entry->apic == apic && entry->pin == pin)
+ return;
+ if (entry->pin == -1)
+ break;
entry = irq_2_pin + entry->next;
+ }

if (entry->pin != -1) {
+ if (entry->apic == apic && entry->pin == pin)
+ return;
entry->next = first_free_entry;
entry = irq_2_pin + entry->next;
if (++first_free_entry >= PIN_MAP_SIZE)
@@ -286,6 +293,24 @@ static void add_pin_to_irq(unsigned int irq, int apic, int pin)
entry->pin = pin;
}

+static void remove_pin_to_irq(unsigned int irq, int apic, int pin)
+{
+ struct irq_pin_list *entry = irq_2_pin + irq;
+
+ BUG_ON(irq >= NR_IRQS);
+
+ while (entry) {
+ if (entry->apic == apic && entry->pin == pin) {
+ entry->apic = -1;
+ entry->pin = -1;
+ break;
+ }
+ if (entry->next)
+ entry = irq_2_pin + entry->next;
+ }
+
+}
+

#define DO_ACTION(name,R,ACTION, FINAL) \
\
@@ -367,6 +392,34 @@ static int find_irq_entry(int apic, int pin, int type)
return -1;
}

+static int add_irq_entry(int type, int irqflag, int bus, int irq, int apic, int pin)
+{
+ struct mpc_config_intsrc intsrc;
+ int idx;
+
+ intsrc.mpc_type = MP_INTSRC;
+ intsrc.mpc_irqflag = irqflag; /* conforming */
+ intsrc.mpc_srcbus = bus;
+ intsrc.mpc_dstapic = (apic != -1) ? mp_ioapics[apic].mpc_apicid: MP_APIC_ALL;
+
+ intsrc.mpc_irqtype = type;
+
+ intsrc.mpc_srcbusirq = irq;
+ intsrc.mpc_dstirq = pin;
+
+ mp_irqs [mp_irq_entries] = intsrc;
+ Dprintk("Int: type %d, pol %d, trig %d, bus %d,"
+ " IRQ %02x, APIC ID %x, APIC INT %02x\n",
+ intsrc.mpc_irqtype, intsrc.mpc_irqflag & 3,
+ (intsrc.mpc_irqflag >> 2) & 3, intsrc.mpc_srcbus,
+ intsrc.mpc_srcbusirq, intsrc.mpc_dstapic, intsrc.mpc_dstirq);
+ idx = mp_irq_entries;
+ if (++mp_irq_entries >= MAX_IRQ_SOURCES)
+ panic("Max # of irq sources exceeded!!\n");
+ return idx;
+
+}
+
/*
* Find the pin to which IRQ[irq] (ISA) is connected
*/
@@ -1570,6 +1658,22 @@ static inline void unlock_ExtINT_logic(void)
* fanatically on his truly buggy board.
*/

+static void set_try_apic_pin(int apic, int pin, int type)
+{
+ int idx;
+ int irq = 0;
+ int bus = 0; /* MP_ISA_BUS */
+ int irqflag = 5; /* MP_IRQ_TRIGGER_EDGE|MP_IRQ_POLARITY_HIGH */
+
+ idx = find_irq_entry(apic,pin,type);
+
+ if (idx == -1)
+ idx = add_irq_entry(type, irqflag, bus, irq, apic, pin);
+
+ add_pin_to_irq(irq, apic, pin);
+ setup_IO_APIC_irq(apic, pin, idx, irq);
+}
+
static int try_apic_pin(int apic, int pin, char *msg)
{
apic_printk(APIC_VERBOSE, KERN_INFO
@@ -1588,7 +1692,7 @@ static int try_apic_pin(int apic, int pin, char *msg)
}
return 1;
}
- clear_IO_APIC_pin(apic, pin);
+
apic_printk(APIC_QUIET, KERN_ERR " .. failed\n");
return 0;
}
@@ -1599,12 +1703,13 @@ static void check_timer(void)
int apic1, pin1, apic2, pin2;
int vector;
cpumask_t mask;
+ int i;

/*
* get/set the timer IRQ vector:
*/
- disable_8259A_irq(0);
vector = assign_irq_vector(0, TARGET_CPUS, &mask);
+ disable_8259A_irq(0);

/*
* Subtle, code in do_timer_interrupt() expects an AEOI
@@ -1621,33 +1726,51 @@ static void check_timer(void)
pin2 = ioapic_i8259.pin;
apic2 = ioapic_i8259.apic;

- /* Do this first, otherwise we get double interrupts on ATI boards */
- if ((pin1 != -1) && try_apic_pin(apic1, pin1,"with 8259 IRQ0 disabled"))
- return;
+ apic_printk(APIC_VERBOSE,KERN_INFO "..TIMER: vector=0x%02X apic1=%d pin1=%d apic2=%d pin2=%d\n",
+ vector, apic1, pin1, apic2, pin2);

- /* Now try again with IRQ0 8259A enabled.
- Assumes timer is on IO-APIC 0 ?!? */
- enable_8259A_irq(0);
- unmask_IO_APIC_irq(0);
- if (try_apic_pin(apic1, pin1, "with 8259 IRQ0 enabled"))
- return;
- disable_8259A_irq(0);
+ if (pin1 != -1) {
+ /* Do this first, otherwise we get double interrupts on ATI boards */
+ /* set_try_apic_pin will call disable_8259A_irq */
+ set_try_apic_pin(apic1, pin1, mp_INT);
+ unmask_IO_APIC_irq(0);
+ if (try_apic_pin(apic1, pin1,"with 8259 IRQ0 disabled"))
+ return;

- /* Always try pin0 and pin2 on APIC 0 to handle buggy timer overrides
- on Nvidia boards */
- if (!(apic1 == 0 && pin1 == 0) &&
- try_apic_pin(0, 0, "fallback with 8259 IRQ0 disabled"))
- return;
- if (!(apic1 == 0 && pin1 == 2) &&
- try_apic_pin(0, 2, "fallback with 8259 IRQ0 disabled"))
- return;
+ /* Now try again with IRQ0 8259A enabled.
+ Assumes timer is on IO-APIC 0 ?!? */
+ enable_8259A_irq(0);
+ if (try_apic_pin(apic1, pin1, "with 8259 IRQ0 enabled"))
+ return;
+ disable_8259A_irq(0);
+
+ clear_IO_APIC_pin(apic1, pin1);
+ remove_pin_to_irq(0, apic1, pin1);
+ }

/* Then try pure 8259A routing on the 8259 as reported by BIOS*/
- enable_8259A_irq(0);
if (pin2 != -1) {
setup_ExtINT_IRQ0_pin(apic2, pin2, vector);
+ add_pin_to_irq(0, apic2, pin2);
+ enable_8259A_irq(0);
if (try_apic_pin(apic2,pin2,"8259A broadcast ExtINT from BIOS"))
return;
+ clear_IO_APIC_pin(apic2, pin2);
+ remove_pin_to_irq(0, apic2, pin2);
+ }
+
+ /* Always try pin0 and pin2 on APIC 0 to handle buggy timer overrides
+ on Nvidia boards */
+ for (i = 0; i <= 2; i += 2)
+ if (!(apic1 == 0 && pin1 == i)) {
+ /* set_try_apic_pin will call disable_8259A_irq */
+ set_try_apic_pin(0, i, mp_INT);
+ unmask_IO_APIC_irq(0);
+ if (try_apic_pin(0, i, "fallback with 8259 IRQ0 disabled"))
+ return;
+
+ clear_IO_APIC_pin(0, i);
+ remove_pin_to_irq(0, 0, i);
}

/* Tried all possibilities to go through the IO-APIC. Now come the