1 files changed, 188 insertions, 0 deletions

diff --git a/arch/x86/kernel/apic_32.c b/arch/x86/kernel/apic_32.c
index 05498c37f8d9..0b11d6e3f091 100644
--- a/arch/x86/kernel/apic_32.c
+++ b/arch/x86/kernel/apic_32.c
@@ -90,6 +90,24 @@ static __init int setup_apicpmtimer(char *s)
 __setup("apicpmtimer", setup_apicpmtimer);
 #endif
 
+#ifdef CONFIG_X86_64
+#define HAVE_X2APIC
+#endif
+
+#ifdef HAVE_X2APIC
+int x2apic;
+/* x2apic enabled before OS handover */
+int x2apic_preenabled;
+int disable_x2apic;
+static __init int setup_nox2apic(char *str)
+{
+        disable_x2apic = 1;
+        setup_clear_cpu_cap(X86_FEATURE_X2APIC);
+        return 0;
+}
+early_param("nox2apic", setup_nox2apic);
+#endif
+
 unsigned long mp_lapic_addr;
 int disable_apic;
 /* Disable local APIC timer from the kernel commandline or via dmi quirk */
@@ -231,6 +249,42 @@ static struct apic_ops xapic_ops = {
 struct apic_ops __read_mostly *apic_ops = &xapic_ops;
 EXPORT_SYMBOL_GPL(apic_ops);
 
+#ifdef HAVE_X2APIC
+static void x2apic_wait_icr_idle(void)
+{
+        /* no need to wait for icr idle in x2apic */
+        return;
+}
+
+static u32 safe_x2apic_wait_icr_idle(void)
+{
+        /* no need to wait for icr idle in x2apic */
+        return 0;
+}
+
+void x2apic_icr_write(u32 low, u32 id)
+{
+        wrmsrl(APIC_BASE_MSR + (APIC_ICR >> 4), ((__u64) id) << 32 | low);
+}
+
+u64 x2apic_icr_read(void)
+{
+        unsigned long val;
+
+        rdmsrl(APIC_BASE_MSR + (APIC_ICR >> 4), val);
+        return val;
+}
+
+static struct apic_ops x2apic_ops = {
+        .read = native_apic_msr_read,
+        .write = native_apic_msr_write,
+        .icr_read = x2apic_icr_read,
+        .icr_write = x2apic_icr_write,
+        .wait_icr_idle = x2apic_wait_icr_idle,
+        .safe_wait_icr_idle = safe_x2apic_wait_icr_idle,
+};
+#endif
+
 /**
  * enable_NMI_through_LVT0 - enable NMI through local vector table 0
  */
@@ -1308,6 +1362,127 @@ void __cpuinit end_local_APIC_setup(void)
         apic_pm_activate();
 }
 
+#ifdef HAVE_X2APIC
+void check_x2apic(void)
+{
+        int msr, msr2;
+
+        rdmsr(MSR_IA32_APICBASE, msr, msr2);
+
+        if (msr & X2APIC_ENABLE) {
+                printk("x2apic enabled by BIOS, switching to x2apic ops\n");
+                x2apic_preenabled = x2apic = 1;
+                apic_ops = &x2apic_ops;
+        }
+}
+
+void enable_x2apic(void)
+{
+        int msr, msr2;
+
+        rdmsr(MSR_IA32_APICBASE, msr, msr2);
+        if (!(msr & X2APIC_ENABLE)) {
+                printk("Enabling x2apic\n");
+                wrmsr(MSR_IA32_APICBASE, msr | X2APIC_ENABLE, 0);
+        }
+}
+
+void enable_IR_x2apic(void)
+{
+#ifdef CONFIG_INTR_REMAP
+        int ret;
+        unsigned long flags;
+
+        if (!cpu_has_x2apic)
+                return;
+
+        if (!x2apic_preenabled && disable_x2apic) {
+                printk(KERN_INFO
+                       "Skipped enabling x2apic and Interrupt-remapping "
+                       "because of nox2apic\n");
+                return;
+        }
+
+        if (x2apic_preenabled && disable_x2apic)
+                panic("Bios already enabled x2apic, can't enforce nox2apic");
+
+        if (!x2apic_preenabled && skip_ioapic_setup) {
+                printk(KERN_INFO
+                       "Skipped enabling x2apic and Interrupt-remapping "
+                       "because of skipping io-apic setup\n");
+                return;
+        }
+
+        ret = dmar_table_init();
+        if (ret) {
+                printk(KERN_INFO
+                       "dmar_table_init() failed with %d:\n", ret);
+
+                if (x2apic_preenabled)
+                        panic("x2apic enabled by bios. But IR enabling failed");
+                else
+                        printk(KERN_INFO
+                               "Not enabling x2apic,Intr-remapping\n");
+                return;
+        }
+
+        local_irq_save(flags);
+        mask_8259A();
+        save_mask_IO_APIC_setup();
+
+        ret = enable_intr_remapping(1);
+
+        if (ret && x2apic_preenabled) {
+                local_irq_restore(flags);
+                panic("x2apic enabled by bios. But IR enabling failed");
+        }
+
+        if (ret)
+                goto end;
+
+        if (!x2apic) {
+                x2apic = 1;
+                apic_ops = &x2apic_ops;
+                enable_x2apic();
+        }
+end:
+        if (ret)
+                /*
+                 * IR enabling failed
+                 */
+                restore_IO_APIC_setup();
+        else
+                reinit_intr_remapped_IO_APIC(x2apic_preenabled);
+
+        unmask_8259A();
+        local_irq_restore(flags);
+
+        if (!ret) {
+                if (!x2apic_preenabled)
+                        printk(KERN_INFO
+                               "Enabled x2apic and interrupt-remapping\n");
+                else
+                        printk(KERN_INFO
+                               "Enabled Interrupt-remapping\n");
+        } else
+                printk(KERN_ERR
+                       "Failed to enable Interrupt-remapping and x2apic\n");
+#else
+        if (!cpu_has_x2apic)
+                return;
+
+        if (x2apic_preenabled)
+                panic("x2apic enabled prior OS handover,"
+                      " enable CONFIG_INTR_REMAP");
+
+        printk(KERN_INFO "Enable CONFIG_INTR_REMAP for enabling intr-remapping "
+               " and x2apic\n");
+#endif
+
+        return;
+}
+#endif /* HAVE_X2APIC */
+
 #ifdef CONFIG_X86_64
 /*
  * Detect and enable local APICs on non-SMP boards.
@@ -1438,6 +1613,13 @@ void __init early_init_lapic_mapping(void)
  */
 void __init init_apic_mappings(void)
 {
+#ifdef HAVE_X2APIC
+        if (x2apic) {
+                boot_cpu_physical_apicid = read_apic_id();
+                return;
+        }
+#endif
+
         /*
          * If no local APIC can be found then set up a fake all
          * zeroes page to simulate the local APIC and another
@@ -1501,6 +1683,7 @@ int __init APIC_init_uniprocessor(void)
 #ifdef CONFIG_X86_64
         setup_apic_routing();
 #endif
+
         verify_local_APIC();
         connect_bsp_APIC();
 
@@ -1879,6 +2062,11 @@ static int lapic_resume(struct sys_device *dev)
 
         local_irq_save(flags);
 
+#ifdef HAVE_X2APIC
+        if (x2apic)
+                enable_x2apic();
+        else
+#endif
         {
                 /*
                  * Make sure the APICBASE points to the right address