[Patch v4 12/16] x86, irq, ACPI: Implement interface to support ACPI based IOAPIC hot-addition

Jiang Liu
2014-08-28T02:22:37Z

Implement acpi_register_ioapic() and enhance mp_register_ioapic()
to support ACPI based IOAPIC hot-addition.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
---
arch/x86/kernel/acpi/boot.c | 31 +++++++++++++++++++++++++++++--
arch/x86/kernel/apic/io_apic.c | 27 ++++++++++++++++++++++++---
2 files changed, 53 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index e23f7460c3f8..796cd9e31ef3 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -764,8 +764,35 @@ EXPORT_SYMBOL(acpi_unmap_lsapic);

int acpi_register_ioapic(acpi_handle handle, u64 phys_addr, u32 gsi_base)
{
- /* TBD */
- return -EINVAL;
+ int ret = -ENOSYS;
+#ifdef CONFIG_ACPI_HOTPLUG_IOAPIC
+ int ioapic_id;
+ u64 addr;
+ struct ioapic_domain_cfg cfg = {
+ .type = IOAPIC_DOMAIN_DYNAMIC,
+ .ops = &acpi_irqdomain_ops,
+ };
+
+ ioapic_id = acpi_get_ioapic_id(handle, gsi_base, &addr);
+ if (ioapic_id < 0) {
+ unsigned long long uid;
+ acpi_status status;
+
+ status = acpi_evaluate_integer(handle, METHOD_NAME__UID,
+ NULL, &uid);
+ if (ACPI_FAILURE(status)) {
+ acpi_handle_warn(handle, "failed to get IOAPIC ID.\n");
+ return -EINVAL;
+ }
+ ioapic_id = (int)uid;
+ }
+
+ down_write(&acpi_ioapic_rwsem);
+ ret = mp_register_ioapic(ioapic_id, phys_addr, gsi_base, &cfg);
+ up_write(&acpi_ioapic_rwsem);
+#endif
+
+ return ret;
}

EXPORT_SYMBOL(acpi_register_ioapic);
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 6e67af0c5f99..b286461cabf9 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -3851,7 +3851,13 @@ static int bad_ioapic_register(int idx)

static int find_free_ioapic_entry(void)
{
- return nr_ioapics;
+ int idx;
+
+ for (idx = 0; idx < MAX_IO_APICS; idx++)
+ if (ioapics[idx].nr_registers == 0)
+ return idx;
+
+ return MAX_IO_APICS;
}

int mp_register_ioapic(int id, u32 address, u32 gsi_base,
@@ -3867,8 +3873,15 @@ int mp_register_ioapic(int id, u32 address, u32 gsi_base,
}
for_each_ioapic(ioapic)
if (ioapics[ioapic].mp_config.apicaddr == address) {
- pr_warn("address 0x%x conflicts with IOAPIC%d\n",
- address, ioapic);
+ /*
+ * IOAPIC unit may also be visible in PCI scope.
+ * When ioapic PCI driver's probe() is called,
+ * the IOAPIC unit may have already been initialized
+ * at boot time.
+ */
+ if (!ioapic_initialized)
+ pr_warn("address 0x%x conflicts with IOAPIC%d\n",
+ address, ioapic);
return -EEXIST;
}

@@ -3918,6 +3931,14 @@ int mp_register_ioapic(int id, u32 address, u32 gsi_base,
ioapics[idx].irqdomain = NULL;
ioapics[idx].irqdomain_cfg = *cfg;

+ if (ioapic_initialized) {
+ if (mp_irqdomain_create(idx)) {
+ clear_fixmap(FIX_IO_APIC_BASE_0 + idx);
+ return -ENOMEM;
+ }
+ alloc_ioapic_saved_registers(idx);
+ }
+
if (gsi_cfg->gsi_end >= gsi_top)
gsi_top = gsi_cfg->gsi_end + 1;
if (nr_ioapics <= idx)
--
1.7.10.4