Merge branch 'x86/urgent' into x86/pat

drivers/pci/dmar.c

@@ -332,6 +332,14 @@ parse_dmar_table(void)
 	entry_header = (struct acpi_dmar_header *)(dmar + 1);
 	while (((unsigned long)entry_header) <
 			(((unsigned long)dmar) + dmar_tbl->length)) {
+		/* Avoid looping forever on bad ACPI tables */
+		if (entry_header->length == 0) {
+			printk(KERN_WARNING PREFIX
+				"Invalid 0-length structure\n");
+			ret = -EINVAL;
+			break;
+		}
+
 		dmar_table_print_dmar_entry(entry_header);
 
 		switch (entry_header->type) {
@@ -494,7 +502,7 @@ int alloc_iommu(struct dmar_drhd_unit *drhd)
 	int map_size;
 	u32 ver;
 	static int iommu_allocated = 0;
-	int agaw;
+	int agaw = 0;
 
 	iommu = kzalloc(sizeof(*iommu), GFP_KERNEL);
 	if (!iommu)
@@ -510,6 +518,7 @@ int alloc_iommu(struct dmar_drhd_unit *drhd)
 	iommu->cap = dmar_readq(iommu->reg + DMAR_CAP_REG);
 	iommu->ecap = dmar_readq(iommu->reg + DMAR_ECAP_REG);
 
+#ifdef CONFIG_DMAR
 	agaw = iommu_calculate_agaw(iommu);
 	if (agaw < 0) {
 		printk(KERN_ERR
@@ -517,6 +526,7 @@ int alloc_iommu(struct dmar_drhd_unit *drhd)
 			iommu->seq_id);
 		goto error;
 	}
+#endif
 	iommu->agaw = agaw;
 
 	/* the registers might be more than one page */
@@ -574,19 +584,49 @@ static inline void reclaim_free_desc(struct q_inval *qi)
 	}
 }
 
+static int qi_check_fault(struct intel_iommu *iommu, int index)
+{
+	u32 fault;
+	int head;
+	struct q_inval *qi = iommu->qi;
+	int wait_index = (index + 1) % QI_LENGTH;
+
+	fault = readl(iommu->reg + DMAR_FSTS_REG);
+
+	/*
+	 * If IQE happens, the head points to the descriptor associated
+	 * with the error. No new descriptors are fetched until the IQE
+	 * is cleared.
+	 */
+	if (fault & DMA_FSTS_IQE) {
+		head = readl(iommu->reg + DMAR_IQH_REG);
+		if ((head >> 4) == index) {
+			memcpy(&qi->desc[index], &qi->desc[wait_index],
+					sizeof(struct qi_desc));
+			__iommu_flush_cache(iommu, &qi->desc[index],
+					sizeof(struct qi_desc));
+			writel(DMA_FSTS_IQE, iommu->reg + DMAR_FSTS_REG);
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
 /*
  * Submit the queued invalidation descriptor to the remapping
  * hardware unit and wait for its completion.
  */
-void qi_submit_sync(struct qi_desc *desc, struct intel_iommu *iommu)
+int qi_submit_sync(struct qi_desc *desc, struct intel_iommu *iommu)
 {
+	int rc = 0;
 	struct q_inval *qi = iommu->qi;
 	struct qi_desc *hw, wait_desc;
 	int wait_index, index;
 	unsigned long flags;
 
 	if (!qi)
-		return;
+		return 0;
 
 	hw = qi->desc;
 
@@ -604,7 +644,8 @@ void qi_submit_sync(struct qi_desc *desc, struct intel_iommu *iommu)
 
 	hw[index] = *desc;
 
-	wait_desc.low = QI_IWD_STATUS_DATA(2) | QI_IWD_STATUS_WRITE | QI_IWD_TYPE;
+	wait_desc.low = QI_IWD_STATUS_DATA(QI_DONE) |
+			QI_IWD_STATUS_WRITE | QI_IWD_TYPE;
 	wait_desc.high = virt_to_phys(&qi->desc_status[wait_index]);
 
 	hw[wait_index] = wait_desc;
@@ -615,13 +656,11 @@ void qi_submit_sync(struct qi_desc *desc, struct intel_iommu *iommu)
 	qi->free_head = (qi->free_head + 2) % QI_LENGTH;
 	qi->free_cnt -= 2;
 
-	spin_lock(&iommu->register_lock);
 	/*
 	 * update the HW tail register indicating the presence of
 	 * new descriptors.
 	 */
 	writel(qi->free_head << 4, iommu->reg + DMAR_IQT_REG);
-	spin_unlock(&iommu->register_lock);
 
 	while (qi->desc_status[wait_index] != QI_DONE) {
 		/*
@@ -631,15 +670,21 @@ void qi_submit_sync(struct qi_desc *desc, struct intel_iommu *iommu)
 		 * a deadlock where the interrupt context can wait indefinitely
 		 * for free slots in the queue.
 		 */
+		rc = qi_check_fault(iommu, index);
+		if (rc)
+			goto out;
+
 		spin_unlock(&qi->q_lock);
 		cpu_relax();
 		spin_lock(&qi->q_lock);
 	}
-
-	qi->desc_status[index] = QI_DONE;
+out:
+	qi->desc_status[index] = qi->desc_status[wait_index] = QI_DONE;
 
 	reclaim_free_desc(qi);
 	spin_unlock_irqrestore(&qi->q_lock, flags);
+
+	return rc;
 }
 
 /*
@@ -652,13 +697,13 @@ void qi_global_iec(struct intel_iommu *iommu)
 	desc.low = QI_IEC_TYPE;
 	desc.high = 0;
 
+	/* should never fail */
 	qi_submit_sync(&desc, iommu);
 }
 
 int qi_flush_context(struct intel_iommu *iommu, u16 did, u16 sid, u8 fm,
 		     u64 type, int non_present_entry_flush)
 {
-
 	struct qi_desc desc;
 
 	if (non_present_entry_flush) {
@@ -672,10 +717,7 @@ int qi_flush_context(struct intel_iommu *iommu, u16 did, u16 sid, u8 fm,
 			| QI_CC_GRAN(type) | QI_CC_TYPE;
 	desc.high = 0;
 
-	qi_submit_sync(&desc, iommu);
-
-	return 0;
-
+	return qi_submit_sync(&desc, iommu);
 }
 
 int qi_flush_iotlb(struct intel_iommu *iommu, u16 did, u64 addr,
@@ -705,10 +747,7 @@ int qi_flush_iotlb(struct intel_iommu *iommu, u16 did, u64 addr,
 	desc.high = QI_IOTLB_ADDR(addr) | QI_IOTLB_IH(ih)
 		| QI_IOTLB_AM(size_order);
 
-	qi_submit_sync(&desc, iommu);
-
-	return 0;
-
+	return qi_submit_sync(&desc, iommu);
 }
 
 /*