x64, x2apic/intr-remap: fix the need for sequential array allocation of iommus

Clean up the intel-iommu code related to deferred iommu flush logic. There is
no need to allocate all the iommu's as a sequential array.

This will be used later in the interrupt-remapping patch series to
allocate iommu much early and individually for each device remapping
hardware unit.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: akpm@linux-foundation.org
Cc: arjan@linux.intel.com
Cc: andi@firstfloor.org
Cc: ebiederm@xmission.com
Cc: jbarnes@virtuousgeek.org
Cc: steiner@sgi.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>

drivers/pci/dmar.c

@@ -377,11 +377,18 @@ int __init early_dmar_detect(void)
 	return (ACPI_SUCCESS(status) ? 1 : 0);
 }
 
-struct intel_iommu *alloc_iommu(struct intel_iommu *iommu,
-				struct dmar_drhd_unit *drhd)
+struct intel_iommu *alloc_iommu(struct dmar_drhd_unit *drhd)
 {
+	struct intel_iommu *iommu;
 	int map_size;
 	u32 ver;
+	static int iommu_allocated = 0;
+
+	iommu = kzalloc(sizeof(*iommu), GFP_KERNEL);
+	if (!iommu)
+		return NULL;
+
+	iommu->seq_id = iommu_allocated++;
 
 	iommu->reg = ioremap(drhd->reg_base_addr, PAGE_SIZE_4K);
 	if (!iommu->reg) {

drivers/pci/intel-iommu.c

@@ -58,8 +58,6 @@ static void flush_unmaps_timeout(unsigned long data);
 
 DEFINE_TIMER(unmap_timer,  flush_unmaps_timeout, 0, 0);
 
-static struct intel_iommu *g_iommus;
-
 #define HIGH_WATER_MARK 250
 struct deferred_flush_tables {
 	int next;
@@ -1649,8 +1647,6 @@ int __init init_dmars(void)
 	 * endfor
 	 */
 	for_each_drhd_unit(drhd) {
-		if (drhd->ignored)
-			continue;
 		g_num_of_iommus++;
 		/*
 		 * lock not needed as this is only incremented in the single
@@ -1659,26 +1655,17 @@ int __init init_dmars(void)
 		 */
 	}
 
-	g_iommus = kzalloc(g_num_of_iommus * sizeof(*iommu), GFP_KERNEL);
-	if (!g_iommus) {
-		ret = -ENOMEM;
-		goto error;
-	}
-
 	deferred_flush = kzalloc(g_num_of_iommus *
 		sizeof(struct deferred_flush_tables), GFP_KERNEL);
 	if (!deferred_flush) {
-		kfree(g_iommus);
 		ret = -ENOMEM;
 		goto error;
 	}
 
-	i = 0;
 	for_each_drhd_unit(drhd) {
 		if (drhd->ignored)
 			continue;
-		iommu = alloc_iommu(&g_iommus[i], drhd);
-		i++;
+		iommu = alloc_iommu(drhd);
 		if (!iommu) {
 			ret = -ENOMEM;
 			goto error;
@@ -1770,7 +1757,6 @@ int __init init_dmars(void)
 		iommu = drhd->iommu;
 		free_iommu(iommu);
 	}
-	kfree(g_iommus);
 	return ret;
 }
 
@@ -1927,7 +1913,10 @@ static void flush_unmaps(void)
 	/* just flush them all */
 	for (i = 0; i < g_num_of_iommus; i++) {
 		if (deferred_flush[i].next) {
-			iommu_flush_iotlb_global(&g_iommus[i], 0);
+			struct intel_iommu *iommu =
+				deferred_flush[i].domain[0]->iommu;
+
+			iommu_flush_iotlb_global(iommu, 0);
 			for (j = 0; j < deferred_flush[i].next; j++) {
 				__free_iova(&deferred_flush[i].domain[j]->iovad,
 						deferred_flush[i].iova[j]);
@@ -1957,7 +1946,8 @@ static void add_unmap(struct dmar_domain *dom, struct iova *iova)
 	if (list_size == HIGH_WATER_MARK)
 		flush_unmaps();
 
-	iommu_id = dom->iommu - g_iommus;
+	iommu_id = dom->iommu->seq_id;
+
 	next = deferred_flush[iommu_id].next;
 	deferred_flush[iommu_id].domain[next] = dom;
 	deferred_flush[iommu_id].iova[next] = iova;

drivers/pci/intel-iommu.h

@@ -182,6 +182,7 @@ struct intel_iommu {
 	int		seg;
 	u32		gcmd; /* Holds TE, EAFL. Don't need SRTP, SFL, WBF */
 	spinlock_t	register_lock; /* protect register handling */
+	int		seq_id;	/* sequence id of the iommu */
 
 #ifdef CONFIG_DMAR
 	unsigned long 	*domain_ids; /* bitmap of domains */
@@ -198,8 +199,7 @@ struct intel_iommu {
 
 extern struct dmar_drhd_unit * dmar_find_matched_drhd_unit(struct pci_dev *dev);
 
-extern struct intel_iommu *alloc_iommu(struct intel_iommu *iommu,
-				       struct dmar_drhd_unit *drhd);
+extern struct intel_iommu *alloc_iommu(struct dmar_drhd_unit *drhd);
 extern void free_iommu(struct intel_iommu *iommu);
 
 #endif