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

Signed-off-by: Jiang Liu <jiang....@linux.intel.com>
---
 arch/x86/kernel/acpi/boot.c    |   37 +++++++++++++++++++++++++++++++++++--
 arch/x86/kernel/apic/io_apic.c |   27 ++++++++++++++++++++++++---
 2 files changed, 59 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 120b573f1e96..85caf3221cde 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -768,8 +768,41 @@ 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) {
+               if (addr != phys_addr) {
+                       acpi_handle_warn(handle,
+                               "IOAPIC physical address doesn't match.\n");
+                       return -EINVAL;
+               }
+       } else  {
+               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 e1cce02e9f55..d26fd3ac1b4b 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -3842,7 +3842,13 @@ 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,
@@ -3858,8 +3864,15 @@ 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;
                }
 
@@ -3909,6 +3922,14 @@ 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

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to