Intel IOMMU Suspend/Resume Support - Interrupt Remapping

This patch enables suspend/resume for interrupt remapping. During suspend,
interrupt remapping is disabled. When resume, interrupt remapping is enabled
again.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 70 insertions, 41 deletions

diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 1bb5c6cee3eb..0ad3fe77641a 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -851,63 +851,74 @@ __setup("pirq=", ioapic_pirq_setup);
 #endif /* CONFIG_X86_32 */
 
 #ifdef CONFIG_INTR_REMAP
-/* I/O APIC RTE contents at the OS boot up */
-static struct IO_APIC_route_entry *early_ioapic_entries[MAX_IO_APICS];
+struct IO_APIC_route_entry **alloc_ioapic_entries(void)
+{
+        int apic;
+        struct IO_APIC_route_entry **ioapic_entries;
+
+        ioapic_entries = kzalloc(sizeof(*ioapic_entries) * nr_ioapics,
+                                GFP_ATOMIC);
+        if (!ioapic_entries)
+                return 0;
+
+        for (apic = 0; apic < nr_ioapics; apic++) {
+                ioapic_entries[apic] =
+                        kzalloc(sizeof(struct IO_APIC_route_entry) *
+                                nr_ioapic_registers[apic], GFP_ATOMIC);
+                if (!ioapic_entries[apic])
+                        goto nomem;
+        }
+
+        return ioapic_entries;
+
+nomem:
+        while (--apic >= 0)
+                kfree(ioapic_entries[apic]);
+        kfree(ioapic_entries);
+
+        return 0;
+}
 
 /*
  * Saves all the IO-APIC RTE's
  */
-int save_IO_APIC_setup(void)
+int save_IO_APIC_setup(struct IO_APIC_route_entry **ioapic_entries)
 {
-        union IO_APIC_reg_01 reg_01;
-        unsigned long flags;
         int apic, pin;
 
-        /*
-         * The number of IO-APIC IRQ registers (== #pins):
-         */
-        for (apic = 0; apic < nr_ioapics; apic++) {
-                spin_lock_irqsave(&ioapic_lock, flags);
-                reg_01.raw = io_apic_read(apic, 1);
-                spin_unlock_irqrestore(&ioapic_lock, flags);
-                nr_ioapic_registers[apic] = reg_01.bits.entries+1;
-        }
+        if (!ioapic_entries)
+                return -ENOMEM;
 
         for (apic = 0; apic < nr_ioapics; apic++) {
-                early_ioapic_entries[apic] =
-                        kzalloc(sizeof(struct IO_APIC_route_entry) *
-                                nr_ioapic_registers[apic], GFP_KERNEL);
-                if (!early_ioapic_entries[apic])
-                        goto nomem;
-        }
+                if (!ioapic_entries[apic])
+                        return -ENOMEM;
 
-        for (apic = 0; apic < nr_ioapics; apic++)
                 for (pin = 0; pin < nr_ioapic_registers[apic]; pin++)
-                        early_ioapic_entries[apic][pin] =
+                        ioapic_entries[apic][pin] =
                                 ioapic_read_entry(apic, pin);
+        }
 
         return 0;
-
-nomem:
-        while (apic >= 0)
-                kfree(early_ioapic_entries[apic--]);
-        memset(early_ioapic_entries, 0,
-                ARRAY_SIZE(early_ioapic_entries));
-
-        return -ENOMEM;
 }
 
-void mask_IO_APIC_setup(void)
+/*
+ * Mask all IO APIC entries.
+ */
+void mask_IO_APIC_setup(struct IO_APIC_route_entry **ioapic_entries)
 {
         int apic, pin;
 
+        if (!ioapic_entries)
+                return;
+
         for (apic = 0; apic < nr_ioapics; apic++) {
-                if (!early_ioapic_entries[apic])
+                if (!ioapic_entries[apic])
                         break;
+
                 for (pin = 0; pin < nr_ioapic_registers[apic]; pin++) {
                         struct IO_APIC_route_entry entry;
 
-                        entry = early_ioapic_entries[apic][pin];
+                        entry = ioapic_entries[apic][pin];
                         if (!entry.mask) {
                                 entry.mask = 1;
                                 ioapic_write_entry(apic, pin, entry);
@@ -916,22 +927,30 @@ void mask_IO_APIC_setup(void)
         }
 }
 
-void restore_IO_APIC_setup(void)
+/*
+ * Restore IO APIC entries which was saved in ioapic_entries.
+ */
+int restore_IO_APIC_setup(struct IO_APIC_route_entry **ioapic_entries)
 {
         int apic, pin;
 
+        if (!ioapic_entries)
+                return -ENOMEM;
+
         for (apic = 0; apic < nr_ioapics; apic++) {
-                if (!early_ioapic_entries[apic])
-                        break;
+                if (!ioapic_entries[apic])
+                        return -ENOMEM;
+
                 for (pin = 0; pin < nr_ioapic_registers[apic]; pin++)
                         ioapic_write_entry(apic, pin,
-                                           early_ioapic_entries[apic][pin]);
-                kfree(early_ioapic_entries[apic]);
-                early_ioapic_entries[apic] = NULL;
+                                        ioapic_entries[apic][pin]);
         }
+        return 0;
 }
 
-void reinit_intr_remapped_IO_APIC(int intr_remapping)
+void reinit_intr_remapped_IO_APIC(int intr_remapping,
+        struct IO_APIC_route_entry **ioapic_entries)
+
 {
         /*
          * for now plain restore of previous settings.
@@ -940,7 +959,17 @@ void reinit_intr_remapped_IO_APIC(int intr_remapping)
          * table entries. for now, do a plain restore, and wait for
          * the setup_IO_APIC_irqs() to do proper initialization.
          */
-        restore_IO_APIC_setup();
+        restore_IO_APIC_setup(ioapic_entries);
+}
+
+void free_ioapic_entries(struct IO_APIC_route_entry **ioapic_entries)
+{
+        int apic;
+
+        for (apic = 0; apic < nr_ioapics; apic++)
+                kfree(ioapic_entries[apic]);
+
+        kfree(ioapic_entries);
 }
 #endif