x86, irq, ACPI: Implement interface to support ACPI based IOAPIC hot-addition

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>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Len Brown <len.brown@intel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Link: http://lkml.kernel.org/r/1414387308-27148-16-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 2d76f02..0b99351 100644 (file)
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -780,8 +780,35 @@ 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;
+       }
+
+       mutex_lock(&acpi_ioapic_lock);
+       ret  = mp_register_ioapic(ioapic_id, phys_addr, gsi_base, &cfg);
+       mutex_unlock(&acpi_ioapic_lock);
+#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 4333a75..826f44f 100644 (file)
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -3861,7 +3861,13 @@ 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;
 }
 
 /**
@@ -3874,6 +3880,7 @@ static int find_free_ioapic_entry(void)
 int mp_register_ioapic(int id, u32 address, u32 gsi_base,
                       struct ioapic_domain_cfg *cfg)
 {
+       bool hotplug = !!ioapic_initialized;
        struct mp_ioapic_gsi *gsi_cfg;
        int idx, ioapic, entries;
        u32 gsi_end;
@@ -3935,6 +3942,19 @@ int mp_register_ioapic(int id, u32 address, u32 gsi_base,
        ioapics[idx].irqdomain = NULL;
        ioapics[idx].irqdomain_cfg = *cfg;
 
+       /*
+        * If mp_register_ioapic() is called during early boot stage when
+        * walking ACPI/SFI/DT tables, it's too early to create irqdomain,
+        * we are still using bootmem allocator. So delay it to setup_IO_APIC().
+        */
+       if (hotplug) {
+               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)