iommu/vt-d: Dynamically allocate and free seq_id for DMAR units

[deliverable/linux.git] / drivers / iommu / dmar.c

diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
index 586dd2aa2ca235d269e96d5c97e7911eba196b88..78aa1b2af1139e762f6725c973af07161f14aca9 100644 (file)
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -70,6 +70,7 @@ LIST_HEAD(dmar_drhd_units);
 struct acpi_table_header * __initdata dmar_tbl;
 static acpi_size dmar_tbl_size;
 static int dmar_dev_scope_status = 1;
+static unsigned long dmar_seq_ids[BITS_TO_LONGS(DMAR_UNITS_SUPPORTED)];
 
 static int alloc_iommu(struct dmar_drhd_unit *drhd);
 static void free_iommu(struct intel_iommu *iommu);
@@ -944,11 +945,32 @@ out:
        return err;
 }
 
+static int dmar_alloc_seq_id(struct intel_iommu *iommu)
+{
+       iommu->seq_id = find_first_zero_bit(dmar_seq_ids,
+                                           DMAR_UNITS_SUPPORTED);
+       if (iommu->seq_id >= DMAR_UNITS_SUPPORTED) {
+               iommu->seq_id = -1;
+       } else {
+               set_bit(iommu->seq_id, dmar_seq_ids);
+               sprintf(iommu->name, "dmar%d", iommu->seq_id);
+       }
+
+       return iommu->seq_id;
+}
+
+static void dmar_free_seq_id(struct intel_iommu *iommu)
+{
+       if (iommu->seq_id >= 0) {
+               clear_bit(iommu->seq_id, dmar_seq_ids);
+               iommu->seq_id = -1;
+       }
+}
+
 static int alloc_iommu(struct dmar_drhd_unit *drhd)
 {
        struct intel_iommu *iommu;
        u32 ver, sts;
-       static int iommu_allocated = 0;
        int agaw = 0;
        int msagaw = 0;
        int err;
@@ -962,13 +984,16 @@ static int alloc_iommu(struct dmar_drhd_unit *drhd)
        if (!iommu)
                return -ENOMEM;
 
-       iommu->seq_id = iommu_allocated++;
-       sprintf (iommu->name, "dmar%d", iommu->seq_id);
+       if (dmar_alloc_seq_id(iommu) < 0) {
+               pr_err("IOMMU: failed to allocate seq_id\n");
+               err = -ENOSPC;
+               goto error;
+       }
 
        err = map_iommu(iommu, drhd->reg_base_addr);
        if (err) {
                pr_err("IOMMU: failed to map %s\n", iommu->name);
-               goto error;
+               goto error_free_seq_id;
        }
 
        err = -EINVAL;
@@ -1018,9 +1043,11 @@ static int alloc_iommu(struct dmar_drhd_unit *drhd)
 
        return 0;
 
- err_unmap:
+err_unmap:
        unmap_iommu(iommu);
- error:
+error_free_seq_id:
+       dmar_free_seq_id(iommu);
+error:
        kfree(iommu);
        return err;
 }
@@ -1044,6 +1071,7 @@ static void free_iommu(struct intel_iommu *iommu)
        if (iommu->reg)
                unmap_iommu(iommu);
 
+       dmar_free_seq_id(iommu);
        kfree(iommu);
 }