x86, x2apic: enable fault handling for intr-remapping

Impact: interface augmentation (not yet used)

Enable fault handling flow for intr-remapping aswell. Fault handling
code now shared by both dma-remapping and intr-remapping.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

1 files changed, 84 insertions, 18 deletions

diff --git a/drivers/pci/dmar.c b/drivers/pci/dmar.c
index 75d34bf2db50..bb4ed985f9c7 100644
--- a/drivers/pci/dmar.c
+++ b/drivers/pci/dmar.c
@@ -511,6 +511,7 @@ int alloc_iommu(struct dmar_drhd_unit *drhd)
                 return -ENOMEM;
 
         iommu->seq_id = iommu_allocated++;
+        sprintf (iommu->name, "dmar%d", iommu->seq_id);
 
         iommu->reg = ioremap(drhd->reg_base_addr, VTD_PAGE_SIZE);
         if (!iommu->reg) {
@@ -817,7 +818,13 @@ int dmar_enable_qi(struct intel_iommu *iommu)
 
 /* iommu interrupt handling. Most stuff are MSI-like. */
 
-static const char *fault_reason_strings[] =
+enum faulttype {
+        DMA_REMAP,
+        INTR_REMAP,
+        UNKNOWN,
+};
+
+static const char *dma_remap_fault_reasons[] =
 {
         "Software",
         "Present bit in root entry is clear",
@@ -833,14 +840,33 @@ static const char *fault_reason_strings[] =
         "non-zero reserved fields in CTP",
         "non-zero reserved fields in PTE",
 };
+
+static const char *intr_remap_fault_reasons[] =
+{
+        "Detected reserved fields in the decoded interrupt-remapped request",
+        "Interrupt index exceeded the interrupt-remapping table size",
+        "Present field in the IRTE entry is clear",
+        "Error accessing interrupt-remapping table pointed by IRTA_REG",
+        "Detected reserved fields in the IRTE entry",
+        "Blocked a compatibility format interrupt request",
+        "Blocked an interrupt request due to source-id verification failure",
+};
+
 #define MAX_FAULT_REASON_IDX    (ARRAY_SIZE(fault_reason_strings) - 1)
 
-const char *dmar_get_fault_reason(u8 fault_reason)
+const char *dmar_get_fault_reason(u8 fault_reason, int *fault_type)
 {
-        if (fault_reason > MAX_FAULT_REASON_IDX)
+        if (fault_reason >= 0x20 && (fault_reason <= 0x20 +
+                                     ARRAY_SIZE(intr_remap_fault_reasons))) {
+                *fault_type = INTR_REMAP;
+                return intr_remap_fault_reasons[fault_reason - 0x20];
+        } else if (fault_reason < ARRAY_SIZE(dma_remap_fault_reasons)) {
+                *fault_type = DMA_REMAP;
+                return dma_remap_fault_reasons[fault_reason];
+        } else {
+                *fault_type = UNKNOWN;
                 return "Unknown";
-        else
-                return fault_reason_strings[fault_reason];
+        }
 }
 
 void dmar_msi_unmask(unsigned int irq)
@@ -897,16 +923,25 @@ static int dmar_fault_do_one(struct intel_iommu *iommu, int type,
                 u8 fault_reason, u16 source_id, unsigned long long addr)
 {
         const char *reason;
+        int fault_type;
 
-        reason = dmar_get_fault_reason(fault_reason);
+        reason = dmar_get_fault_reason(fault_reason, &fault_type);
 
-        printk(KERN_ERR
-                "DMAR:[%s] Request device [%02x:%02x.%d] "
-                "fault addr %llx \n"
-                "DMAR:[fault reason %02d] %s\n",
-                (type ? "DMA Read" : "DMA Write"),
-                (source_id >> 8), PCI_SLOT(source_id & 0xFF),
-                PCI_FUNC(source_id & 0xFF), addr, fault_reason, reason);
+        if (fault_type == INTR_REMAP)
+                printk(KERN_ERR "INTR-REMAP: Request device [[%02x:%02x.%d] "
+                       "fault index %llx\n"
+                        "INTR-REMAP:[fault reason %02d] %s\n",
+                        (source_id >> 8), PCI_SLOT(source_id & 0xFF),
+                        PCI_FUNC(source_id & 0xFF), addr >> 48,
+                        fault_reason, reason);
+        else
+                printk(KERN_ERR
+                       "DMAR:[%s] Request device [%02x:%02x.%d] "
+                       "fault addr %llx \n"
+                       "DMAR:[fault reason %02d] %s\n",
+                       (type ? "DMA Read" : "DMA Write"),
+                       (source_id >> 8), PCI_SLOT(source_id & 0xFF),
+                       PCI_FUNC(source_id & 0xFF), addr, fault_reason, reason);
         return 0;
 }
 
@@ -920,10 +955,13 @@ static irqreturn_t dmar_fault(int irq, void *dev_id)
 
         spin_lock_irqsave(&iommu->register_lock, flag);
         fault_status = readl(iommu->reg + DMAR_FSTS_REG);
+        if (fault_status)
+                printk(KERN_ERR "DRHD: handling fault status reg %x\n",
+                       fault_status);
 
         /* TBD: ignore advanced fault log currently */
         if (!(fault_status & DMA_FSTS_PPF))
-                goto clear_overflow;
+                goto clear_rest;
 
         fault_index = dma_fsts_fault_record_index(fault_status);
         reg = cap_fault_reg_offset(iommu->cap);
@@ -964,11 +1002,10 @@ static irqreturn_t dmar_fault(int irq, void *dev_id)
                         fault_index = 0;
                 spin_lock_irqsave(&iommu->register_lock, flag);
         }
-clear_overflow:
-        /* clear primary fault overflow */
+clear_rest:
+        /* clear all the other faults */
         fault_status = readl(iommu->reg + DMAR_FSTS_REG);
-        if (fault_status & DMA_FSTS_PFO)
-                writel(DMA_FSTS_PFO, iommu->reg + DMAR_FSTS_REG);
+        writel(fault_status, iommu->reg + DMAR_FSTS_REG);
 
         spin_unlock_irqrestore(&iommu->register_lock, flag);
         return IRQ_HANDLED;
@@ -978,6 +1015,12 @@ int dmar_set_interrupt(struct intel_iommu *iommu)
 {
         int irq, ret;
 
+        /*
+         * Check if the fault interrupt is already initialized.
+         */
+        if (iommu->irq)
+                return 0;
+
         irq = create_irq();
         if (!irq) {
                 printk(KERN_ERR "IOMMU: no free vectors\n");
@@ -1003,3 +1046,26 @@ int dmar_set_interrupt(struct intel_iommu *iommu)
                 printk(KERN_ERR "IOMMU: can't request irq\n");
         return ret;
 }
+
+int __init enable_drhd_fault_handling(void)
+{
+        struct dmar_drhd_unit *drhd;
+
+        /*
+         * Enable fault control interrupt.
+         */
+        for_each_drhd_unit(drhd) {
+                int ret;
+                struct intel_iommu *iommu = drhd->iommu;
+                ret = dmar_set_interrupt(iommu);
+
+                if (ret) {
+                        printk(KERN_ERR "DRHD %Lx: failed to enable fault, "
+                               " interrupt, ret %d\n",
+                               (unsigned long long)drhd->reg_base_addr, ret);
+                        return -1;
+                }
+        }
+
+        return 0;
+}