intr_remap: Call dmar_dev_scope_init() explicitly

Both DMA-remapping aswell as Interrupt-remapping depend on the
dmar dev scope to be initialized. When both DMA and
IRQ-remapping are enabled, we depend on DMA-remapping init code
to call dmar_dev_scope_init(). This resulted in not doing this
init when DMA-remapping was turned off but interrupt-remapping
turned on in the kernel config.

This caused interrupt routing to break with CONFIG_INTR_REMAP=y
and CONFIG_DMAR=n.

This issue was introduced by this commit:

 | commit 9d5ce73a64be2be8112147a3e0b551ad9cd1247b
 | Author: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
 | Date:   Tue Nov 10 19:46:16 2009 +0900
 |
 |    x86: intel-iommu: Convert detect_intel_iommu to use iommu_init hook

Fix this by calling dmar_dev_scope_init() explicitly from the
interrupt remapping code too.

Reported-by: Andrew Vasquez <andrew.vasquez@qlogic.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: yinghai@kernel.org
Cc: youquan.song@intel.com
Cc: joerg.roedel@amd.com
Cc: tony.luck@intel.com
Cc: dwmw2@infradead.org
Link: http://lkml.kernel.org/r/20110824001456.229207526@sbsiddha-desk.sc.intel.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>

3 files changed, 22 insertions, 8 deletions

diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
index c4a0235a4fdb..17adf1ebcb13 100644
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -557,13 +557,17 @@ dmar_find_matched_drhd_unit(struct pci_dev *dev)
 
 int __init dmar_dev_scope_init(void)
 {
+        static int dmar_dev_scope_initialized;
         struct dmar_drhd_unit *drhd, *drhd_n;
         int ret = -ENODEV;
 
+        if (dmar_dev_scope_initialized)
+                return dmar_dev_scope_initialized;
+
         list_for_each_entry_safe(drhd, drhd_n, &dmar_drhd_units, list) {
                 ret = dmar_parse_dev(drhd);
                 if (ret)
-                        return ret;
+                        goto fail;
         }
 
 #ifdef CONFIG_DMAR
@@ -574,17 +578,22 @@ int __init dmar_dev_scope_init(void)
                 list_for_each_entry_safe(rmrr, rmrr_n, &dmar_rmrr_units, list) {
                         ret = rmrr_parse_dev(rmrr);
                         if (ret)
-                                return ret;
+                                goto fail;
                 }
 
                 list_for_each_entry_safe(atsr, atsr_n, &dmar_atsr_units, list) {
                         ret = atsr_parse_dev(atsr);
                         if (ret)
-                                return ret;
+                                goto fail;
                 }
         }
 #endif
 
+        dmar_dev_scope_initialized = 1;
+        return 0;
+
+fail:
+        dmar_dev_scope_initialized = ret;
         return ret;
 }
 
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index c621c98c99da..df69618177c5 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -3439,16 +3439,12 @@ int __init intel_iommu_init(void)
                 return  -ENODEV;
         }
 
-        if (dmar_dev_scope_init()) {
+        if (dmar_dev_scope_init() < 0) {
                 if (force_on)
                         panic("tboot: Failed to initialize DMAR device scope\n");
                 return  -ENODEV;
         }
 
-        /*
-         * Check the need for DMA-remapping initialization now.
-         * Above initialization will also be used by Interrupt-remapping.
-         */
         if (no_iommu || dmar_disabled)
                 return -ENODEV;
 
diff --git a/drivers/iommu/intr_remapping.c b/drivers/iommu/intr_remapping.c
index 51a2ce9b8789..cfb0dd4bf0b6 100644
--- a/drivers/iommu/intr_remapping.c
+++ b/drivers/iommu/intr_remapping.c
@@ -773,6 +773,15 @@ int __init parse_ioapics_under_ir(void)
         return ir_supported;
 }
 
+int ir_dev_scope_init(void)
+{
+        if (!intr_remapping_enabled)
+                return 0;
+
+        return dmar_dev_scope_init();
+}
+rootfs_initcall(ir_dev_scope_init);
+
 void disable_intr_remapping(void)
 {
         struct dmar_drhd_unit *drhd;