iommu/vt-d: Dynamically allocate and free seq_id for DMAR units
Introduce functions to support dynamic IOMMU seq_id allocating and
releasing, which will be used to support DMAR hotplug.
Also rename IOMMU_UNITS_SUPPORTED as DMAR_UNITS_SUPPORTED.
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Reviewed-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
index 586dd2a..78aa1b2 100644
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -70,6 +70,7 @@
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 @@
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 @@
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 @@
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 @@
if (iommu->reg)
unmap_iommu(iommu);
+ dmar_free_seq_id(iommu);
kfree(iommu);
}