[PATCH v2 22/26] x86, irq: Make ioapics loop skip blank slots

Yinghai Lu
2013-02-08T19:32:14Z

When multiple ioapics get added and removed, we could have blank slots
in middle of ioapics array.

Add skip code for this case by checking nr_registers.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
---
arch/x86/kernel/apic/io_apic.c | 29 +++++++++++++++++++++++------
1 file changed, 23 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 4a9ccf6..d4c68d9 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -793,7 +793,8 @@ int save_ioapic_entries(void)
int err = 0;

for (apic = 0; apic < nr_ioapics; apic++) {
- if (!ioapics[apic].saved_registers) {
+ if (!ioapics[apic].saved_registers &&
+ ioapics[apic].nr_registers) {
err = -ENOMEM;
continue;
}
@@ -899,9 +900,12 @@ static int __init find_isa_irq_apic(int irq, int type)
if (i < mp_irq_entries) {
int ioapic_idx;

- for (ioapic_idx = 0; ioapic_idx < nr_ioapics; ioapic_idx++)
+ for (ioapic_idx = 0; ioapic_idx < nr_ioapics; ioapic_idx++) {
+ if (!ioapics[ioapic_idx].nr_registers)
+ continue;
if (mpc_ioapic_id(ioapic_idx) == mp_irqs[i].dstapic)
return ioapic_idx;
+ }
}

return -1;
@@ -1121,10 +1125,13 @@ int IO_APIC_get_PCI_irq_vector(int bus, int slot, int pin,
for (i = 0; i < mp_irq_entries; i++) {
int lbus = mp_irqs[i].srcbus;

- for (ioapic_idx = 0; ioapic_idx < nr_ioapics; ioapic_idx++)
+ for (ioapic_idx = 0; ioapic_idx < nr_ioapics; ioapic_idx++) {
+ if (!ioapics[ioapic_idx].nr_registers)
+ continue;
if (mpc_ioapic_id(ioapic_idx) == mp_irqs[i].dstapic ||
mp_irqs[i].dstapic == MP_APIC_ALL)
break;
+ }

if (!test_bit(lbus, mp_bus_not_pci) &&
!mp_irqs[i].irqtype &&
@@ -2084,6 +2091,9 @@ void __init setup_ioapic_ids_from_mpc_nocheck(void)
* Set the IOAPIC ID to the value stored in the MPC table.
*/
for (ioapic_idx = 0; ioapic_idx < nr_ioapics; ioapic_idx++) {
+ if (!ioapics[ioapic_idx].nr_registers)
+ continue;
+
/* Read the register 0 value */
raw_spin_lock_irqsave(&ioapic_lock, flags);
reg_00.raw = io_apic_read(ioapic_idx, 0);
@@ -3013,8 +3023,12 @@ static void ioapic_resume(void)
{
int ioapic_idx;

- for (ioapic_idx = nr_ioapics - 1; ioapic_idx >= 0; ioapic_idx--)
+ for (ioapic_idx = nr_ioapics - 1; ioapic_idx >= 0; ioapic_idx--) {
+ if (!ioapics[ioapic_idx].nr_registers)
+ continue;
+
resume_ioapic_id(ioapic_idx);
+ }

restore_ioapic_entries();
}
@@ -3854,8 +3868,11 @@ static int __mp_find_ioapic(u32 gsi, bool quiet)
/* Find the IOAPIC that manages this GSI. */
for (i = 0; i < nr_ioapics; i++) {
struct mp_ioapic_gsi *gsi_cfg = mp_ioapic_gsi_routing(i);
- if ((gsi >= gsi_cfg->gsi_base)
- && (gsi <= gsi_cfg->gsi_end))
+
+ if (!ioapics[i].nr_registers)
+ continue;
+
+ if ((gsi >= gsi_cfg->gsi_base) && (gsi <= gsi_cfg->gsi_end))
return i;
}

--
1.7.10.4