5 files changed, 54 insertions, 67 deletions

diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index d4cb7e590c06..fbdd65446c7a 100644
--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -169,7 +169,6 @@ static inline u64 native_x2apic_icr_read(void)
 extern int x2apic, x2apic_phys;
 extern void check_x2apic(void);
 extern void enable_x2apic(void);
-extern void enable_IR_x2apic(void);
 extern void x2apic_icr_write(u32 low, u32 id);
 static inline int x2apic_enabled(void)
 {
@@ -190,18 +189,18 @@ static inline void check_x2apic(void)
 static inline void enable_x2apic(void)
 {
 }
-static inline void enable_IR_x2apic(void)
-{
-}
 static inline int x2apic_enabled(void)
 {
         return 0;
 }
 
 #define x2apic  0
+#define x2apic_preenabled 0
 
 #endif
 
+extern void enable_IR_x2apic(void);
+
 extern int get_physical_broadcast(void);
 
 extern void apic_disable(void);
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 83e47febcc89..0cf1eea750cc 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -141,6 +141,8 @@ static int x2apic_preenabled;
 static int disable_x2apic;
 static __init int setup_nox2apic(char *str)
 {
+        if (x2apic_enabled())
+                panic("Bios already enabled x2apic, can't enforce nox2apic");
         disable_x2apic = 1;
         setup_clear_cpu_cap(X86_FEATURE_X2APIC);
         return 0;
@@ -1345,6 +1347,7 @@ void enable_x2apic(void)
                 wrmsr(MSR_IA32_APICBASE, msr | X2APIC_ENABLE, 0);
         }
 }
+#endif /* CONFIG_X86_X2APIC */
 
 void __init enable_IR_x2apic(void)
 {
@@ -1353,32 +1356,21 @@ void __init enable_IR_x2apic(void)
         unsigned long flags;
         struct IO_APIC_route_entry **ioapic_entries = NULL;
 
-        if (!cpu_has_x2apic)
-                return;
-
-        if (!x2apic_preenabled && disable_x2apic) {
-                pr_info("Skipped enabling x2apic and Interrupt-remapping "
-                        "because of nox2apic\n");
-                return;
+        ret = dmar_table_init();
+        if (ret) {
+                pr_debug("dmar_table_init() failed with %d:\n", ret);
+                goto ir_failed;
         }
 
-        if (x2apic_preenabled && disable_x2apic)
-                panic("Bios already enabled x2apic, can't enforce nox2apic");
-
-        if (!x2apic_preenabled && skip_ioapic_setup) {
-                pr_info("Skipped enabling x2apic and Interrupt-remapping "
-                        "because of skipping io-apic setup\n");
-                return;
+        if (!intr_remapping_supported()) {
+                pr_debug("intr-remapping not supported\n");
+                goto ir_failed;
         }
 
-        ret = dmar_table_init();
-        if (ret) {
-                pr_info("dmar_table_init() failed with %d:\n", ret);
 
-                if (x2apic_preenabled)
-                        panic("x2apic enabled by bios. But IR enabling failed");
-                else
-                        pr_info("Not enabling x2apic,Intr-remapping\n");
+        if (!x2apic_preenabled && skip_ioapic_setup) {
+                pr_info("Skipped enabling intr-remap because of skipping "
+                        "io-apic setup\n");
                 return;
         }
 
@@ -1398,20 +1390,25 @@ void __init enable_IR_x2apic(void)
         mask_IO_APIC_setup(ioapic_entries);
         mask_8259A();
 
-        ret = enable_intr_remapping(EIM_32BIT_APIC_ID);
-
-        if (ret && x2apic_preenabled) {
-                local_irq_restore(flags);
-                panic("x2apic enabled by bios. But IR enabling failed");
-        }
+#ifdef CONFIG_X86_X2APIC
+        if (cpu_has_x2apic)
+                ret = enable_intr_remapping(EIM_32BIT_APIC_ID);
+        else
+#endif
+                ret = enable_intr_remapping(EIM_8BIT_APIC_ID);
 
         if (ret)
                 goto end_restore;
 
-        if (!x2apic) {
+        pr_info("Enabled Interrupt-remapping\n");
+
+#ifdef CONFIG_X86_X2APIC
+        if (cpu_has_x2apic && !x2apic) {
                 x2apic = 1;
                 enable_x2apic();
+                pr_info("Enabled x2apic\n");
         }
+#endif
 
 end_restore:
         if (ret)
@@ -1426,30 +1423,29 @@ end_restore:
         local_irq_restore(flags);
 
 end:
-        if (!ret) {
-                if (!x2apic_preenabled)
-                        pr_info("Enabled x2apic and interrupt-remapping\n");
-                else
-                        pr_info("Enabled Interrupt-remapping\n");
-        } else
-                pr_err("Failed to enable Interrupt-remapping and x2apic\n");
         if (ioapic_entries)
                 free_ioapic_entries(ioapic_entries);
+
+        if (!ret)
+                return;
+
+ir_failed:
+        if (x2apic_preenabled)
+                panic("x2apic enabled by bios. But IR enabling failed");
+        else if (cpu_has_x2apic)
+                pr_info("Not enabling x2apic,Intr-remapping\n");
 #else
         if (!cpu_has_x2apic)
                 return;
 
         if (x2apic_preenabled)
                 panic("x2apic enabled prior OS handover,"
-                      " enable CONFIG_INTR_REMAP");
-
-        pr_info("Enable CONFIG_INTR_REMAP for enabling intr-remapping "
-                " and x2apic\n");
+                      " enable CONFIG_X86_X2APIC, CONFIG_INTR_REMAP");
 #endif
 
         return;
 }
-#endif /* CONFIG_X86_X2APIC */
+
 
 #ifdef CONFIG_X86_64
 /*
diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c
index 001b328adf80..9ce8f0764bef 100644
--- a/drivers/pci/intel-iommu.c
+++ b/drivers/pci/intel-iommu.c
@@ -1968,15 +1968,6 @@ static int __init init_dmars(void)
                 }
         }
 
-#ifdef CONFIG_INTR_REMAP
-        if (!intr_remapping_enabled) {
-                ret = enable_intr_remapping(0);
-                if (ret)
-                        printk(KERN_ERR
-                               "IOMMU: enable interrupt remapping failed\n");
-        }
-#endif
-
         /*
          * For each rmrr
          *   for each dev attached to rmrr
diff --git a/drivers/pci/intr_remapping.c b/drivers/pci/intr_remapping.c
index f5e0ea724a6f..5c2142656e96 100644
--- a/drivers/pci/intr_remapping.c
+++ b/drivers/pci/intr_remapping.c
@@ -423,20 +423,6 @@ static void iommu_set_intr_remapping(struct intel_iommu *iommu, int mode)
                       readl, (sts & DMA_GSTS_IRTPS), sts);
         spin_unlock_irqrestore(&iommu->register_lock, flags);
 
-        if (mode == 0) {
-                spin_lock_irqsave(&iommu->register_lock, flags);
-
-                /* enable comaptiblity format interrupt pass through */
-                cmd = iommu->gcmd | DMA_GCMD_CFI;
-                iommu->gcmd |= DMA_GCMD_CFI;
-                writel(cmd, iommu->reg + DMAR_GCMD_REG);
-
-                IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG,
-                              readl, (sts & DMA_GSTS_CFIS), sts);
-
-                spin_unlock_irqrestore(&iommu->register_lock, flags);
-        }
-
         /*
          * global invalidation of interrupt entry cache before enabling
          * interrupt-remapping.
@@ -516,6 +502,20 @@ end:
         spin_unlock_irqrestore(&iommu->register_lock, flags);
 }
 
+int __init intr_remapping_supported(void)
+{
+        struct dmar_drhd_unit *drhd;
+
+        for_each_drhd_unit(drhd) {
+                struct intel_iommu *iommu = drhd->iommu;
+
+                if (!ecap_ir_support(iommu->ecap))
+                        return 0;
+        }
+
+        return 1;
+}
+
 int __init enable_intr_remapping(int eim)
 {
         struct dmar_drhd_unit *drhd;
diff --git a/include/linux/dmar.h b/include/linux/dmar.h
index e397dc342cda..06f592a7f73c 100644
--- a/include/linux/dmar.h
+++ b/include/linux/dmar.h
@@ -108,6 +108,7 @@ struct irte {
 };
 #ifdef CONFIG_INTR_REMAP
 extern int intr_remapping_enabled;
+extern int intr_remapping_supported(void);
 extern int enable_intr_remapping(int);
 extern void disable_intr_remapping(void);
 extern int reenable_intr_remapping(int);