Re: [PATCH v1 2/6] iommu/vt-d: Use IDA interface to manage iommu sequence id

[Lu Baolu]

On 6/30/22 4:21 PM, Tian, Kevin wrote:
From: Lu Baolu <baolu...@linux.intel.com>
Sent: Saturday, June 25, 2022 8:52 PM
@@ -1062,11 +1040,14 @@ static int alloc_iommu(struct dmar_drhd_unit
*drhd)
        if (!iommu)
                return -ENOMEM;

-       if (dmar_alloc_seq_id(iommu) < 0) {
+       iommu->seq_id = ida_alloc_range(&dmar_seq_ids, 0,
+                                       DMAR_UNITS_SUPPORTED,

should be "DMAR_UNITS_SUPPORTED - 1"

Yes, according to "@max: Highest ID to allocate.". Updated.

GFP_KERNEL);
+       if (iommu->seq_id < 0) {
                pr_err("Failed to allocate seq_id\n");
                err = -ENOSPC;
                goto error;
        }

ida_alloc_range() returns error code already. No need to change it.


Agreed. Updated as below:

diff --git a/drivers/iommu/intel/dmar.c b/drivers/iommu/intel/dmar.c
index bf43889b9d2a..6327b34f5aa7 100644
--- a/drivers/iommu/intel/dmar.c
+++ b/drivers/iommu/intel/dmar.c
@@ -1041,10 +1041,10 @@ static int alloc_iommu(struct dmar_drhd_unit *drhd)
                return -ENOMEM;

        iommu->seq_id = ida_alloc_range(&dmar_seq_ids, 0,
-                                       DMAR_UNITS_SUPPORTED, GFP_KERNEL);
+                                       DMAR_UNITS_SUPPORTED - 1, 
GFP_KERNEL);
        if (iommu->seq_id < 0) {
                pr_err("Failed to allocate seq_id\n");
-               err = -ENOSPC;
+               err = iommu->seq_id;
                goto error;
        }
        sprintf(iommu->name, "dmar%d", iommu->seq_id);

Best regards,
baolu
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