1 files changed, 25 insertions, 31 deletions

diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index 35af5b470421..f831526b65f4 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -18,6 +18,7 @@
 #include <linux/scatterlist.h>
 #include <linux/dma-map-ops.h>
 #include <linux/dma-direct.h>
+#include <linux/idr.h>
 #include <linux/iommu-helper.h>
 #include <linux/delay.h>
 #include <linux/amd-iommu.h>
@@ -52,8 +53,6 @@
 #define HT_RANGE_START		(0xfd00000000ULL)
 #define HT_RANGE_END		(0xffffffffffULL)
 
-static DEFINE_SPINLOCK(pd_bitmap_lock);
-
 LIST_HEAD(ioapic_map);
 LIST_HEAD(hpet_map);
 LIST_HEAD(acpihid_map);
@@ -70,6 +69,12 @@ struct iommu_cmd {
 	u32 data[4];
 };
 
+/*
+ * AMD IOMMU allows up to 2^16 different protection domains. This is a bitmap
+ * to know which ones are already in use.
+ */
+DEFINE_IDA(pdom_ids);
+
 struct kmem_cache *amd_iommu_irq_cache;
 
 static void detach_device(struct device *dev);
@@ -1643,31 +1648,14 @@ int amd_iommu_complete_ppr(struct device *dev, u32 pasid, int status, int tag)
  *
  ****************************************************************************/
 
-static u16 domain_id_alloc(void)
+static int pdom_id_alloc(void)
 {
-	unsigned long flags;
-	int id;
-
-	spin_lock_irqsave(&pd_bitmap_lock, flags);
-	id = find_first_zero_bit(amd_iommu_pd_alloc_bitmap, MAX_DOMAIN_ID);
-	BUG_ON(id == 0);
-	if (id > 0 && id < MAX_DOMAIN_ID)
-		__set_bit(id, amd_iommu_pd_alloc_bitmap);
-	else
-		id = 0;
-	spin_unlock_irqrestore(&pd_bitmap_lock, flags);
-
-	return id;
+	return ida_alloc_range(&pdom_ids, 1, MAX_DOMAIN_ID - 1, GFP_ATOMIC);
 }
 
-static void domain_id_free(int id)
+static void pdom_id_free(int id)
 {
-	unsigned long flags;
-
-	spin_lock_irqsave(&pd_bitmap_lock, flags);
-	if (id > 0 && id < MAX_DOMAIN_ID)
-		__clear_bit(id, amd_iommu_pd_alloc_bitmap);
-	spin_unlock_irqrestore(&pd_bitmap_lock, flags);
+	ida_free(&pdom_ids, id);
 }
 
 static void free_gcr3_tbl_level1(u64 *tbl)
@@ -1712,7 +1700,7 @@ static void free_gcr3_table(struct gcr3_tbl_info *gcr3_info)
 	gcr3_info->glx = 0;
 
 	/* Free per device domain ID */
-	domain_id_free(gcr3_info->domid);
+	pdom_id_free(gcr3_info->domid);
 
 	iommu_free_page(gcr3_info->gcr3_tbl);
 	gcr3_info->gcr3_tbl = NULL;
@@ -1739,6 +1727,7 @@ static int setup_gcr3_table(struct gcr3_tbl_info *gcr3_info,
 {
 	int levels = get_gcr3_levels(pasids);
 	int nid = iommu ? dev_to_node(&iommu->dev->dev) : NUMA_NO_NODE;
+	int domid;
 
 	if (levels > amd_iommu_max_glx_val)
 		return -EINVAL;
@@ -1747,11 +1736,14 @@ static int setup_gcr3_table(struct gcr3_tbl_info *gcr3_info,
 		return -EBUSY;
 
 	/* Allocate per device domain ID */
-	gcr3_info->domid = domain_id_alloc();
+	domid = pdom_id_alloc();
+	if (domid <= 0)
+		return -ENOSPC;
+	gcr3_info->domid = domid;
 
 	gcr3_info->gcr3_tbl = iommu_alloc_page_node(nid, GFP_ATOMIC);
 	if (gcr3_info->gcr3_tbl == NULL) {
-		domain_id_free(gcr3_info->domid);
+		pdom_id_free(domid);
 		return -ENOMEM;
 	}
 
@@ -2262,7 +2254,7 @@ void protection_domain_free(struct protection_domain *domain)
 	WARN_ON(!list_empty(&domain->dev_list));
 	if (domain->domain.type & __IOMMU_DOMAIN_PAGING)
 		free_io_pgtable_ops(&domain->iop.pgtbl.ops);
-	domain_id_free(domain->id);
+	pdom_id_free(domain->id);
 	kfree(domain);
 }
 
@@ -2277,16 +2269,18 @@ static void protection_domain_init(struct protection_domain *domain, int nid)
 struct protection_domain *protection_domain_alloc(unsigned int type, int nid)
 {
 	struct protection_domain *domain;
+	int domid;
 
 	domain = kzalloc(sizeof(*domain), GFP_KERNEL);
 	if (!domain)
 		return NULL;
 
-	domain->id = domain_id_alloc();
-	if (!domain->id) {
+	domid = pdom_id_alloc();
+	if (domid <= 0) {
 		kfree(domain);
 		return NULL;
 	}
+	domain->id = domid;
 
 	protection_domain_init(domain, nid);
 
@@ -2361,7 +2355,7 @@ static struct iommu_domain *do_iommu_domain_alloc(unsigned int type,
 
 	ret = pdom_setup_pgtable(domain, type, pgtable);
 	if (ret) {
-		domain_id_free(domain->id);
+		pdom_id_free(domain->id);
 		kfree(domain);
 		return ERR_PTR(ret);
 	}
@@ -2493,7 +2487,7 @@ void amd_iommu_init_identity_domain(void)
 	domain->ops = &identity_domain_ops;
 	domain->owner = &amd_iommu_ops;
 
-	identity_domain.id = domain_id_alloc();
+	identity_domain.id = pdom_id_alloc();
 
 	protection_domain_init(&identity_domain, NUMA_NO_NODE);
 }