iommu/vt-d: Remove intel_iommu::domains

The "domains" field of the intel_iommu structure keeps the mapping of
domain_id to dmar_domain. This information is not used anywhere. Remove
and cleanup it to avoid unnecessary memory consumption.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20220214025704.3184654-1-baolu.lu@linux.intel.com
Link: https://lore.kernel.org/r/20220301020159.633356-2-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index b549172e88ef9785a65f5cf60de1201031e41425..e3b04d5d87b09e9fc9d7a789ba5f1319db7cba3c 100644 (file)
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -455,36 +455,6 @@ __setup("intel_iommu=", intel_iommu_setup);
 static struct kmem_cache *iommu_domain_cache;
 static struct kmem_cache *iommu_devinfo_cache;
 
-static struct dmar_domain* get_iommu_domain(struct intel_iommu *iommu, u16 did)
-{
-       struct dmar_domain **domains;
-       int idx = did >> 8;
-
-       domains = iommu->domains[idx];
-       if (!domains)
-               return NULL;
-
-       return domains[did & 0xff];
-}
-
-static void set_iommu_domain(struct intel_iommu *iommu, u16 did,
-                            struct dmar_domain *domain)
-{
-       struct dmar_domain **domains;
-       int idx = did >> 8;
-
-       if (!iommu->domains[idx]) {
-               size_t size = 256 * sizeof(struct dmar_domain *);
-               iommu->domains[idx] = kzalloc(size, GFP_ATOMIC);
-       }
-
-       domains = iommu->domains[idx];
-       if (WARN_ON(!domains))
-               return;
-       else
-               domains[did & 0xff] = domain;
-}
-
 void *alloc_pgtable_page(int node)
 {
        struct page *page;
@@ -1751,8 +1721,7 @@ static void intel_flush_iotlb_all(struct iommu_domain *domain)
                                                 DMA_TLB_DSI_FLUSH);
 
                if (!cap_caching_mode(iommu->cap))
-                       iommu_flush_dev_iotlb(get_iommu_domain(iommu, did),
-                                             0, MAX_AGAW_PFN_WIDTH);
+                       iommu_flush_dev_iotlb(dmar_domain, 0, MAX_AGAW_PFN_WIDTH);
        }
 }
 
@@ -1815,7 +1784,6 @@ static void iommu_disable_translation(struct intel_iommu *iommu)
 static int iommu_init_domains(struct intel_iommu *iommu)
 {
        u32 ndomains;
-       size_t size;
 
        ndomains = cap_ndoms(iommu->cap);
        pr_debug("%s: Number of Domains supported <%d>\n",
@@ -1827,24 +1795,6 @@ static int iommu_init_domains(struct intel_iommu *iommu)
        if (!iommu->domain_ids)
                return -ENOMEM;
 
-       size = (ALIGN(ndomains, 256) >> 8) * sizeof(struct dmar_domain **);
-       iommu->domains = kzalloc(size, GFP_KERNEL);
-
-       if (iommu->domains) {
-               size = 256 * sizeof(struct dmar_domain *);
-               iommu->domains[0] = kzalloc(size, GFP_KERNEL);
-       }
-
-       if (!iommu->domains || !iommu->domains[0]) {
-               pr_err("%s: Allocating domain array failed\n",
-                      iommu->name);
-               bitmap_free(iommu->domain_ids);
-               kfree(iommu->domains);
-               iommu->domain_ids = NULL;
-               iommu->domains    = NULL;
-               return -ENOMEM;
-       }
-
        /*
         * If Caching mode is set, then invalid translations are tagged
         * with domain-id 0, hence we need to pre-allocate it. We also
@@ -1871,7 +1821,7 @@ static void disable_dmar_iommu(struct intel_iommu *iommu)
        struct device_domain_info *info, *tmp;
        unsigned long flags;
 
-       if (!iommu->domains || !iommu->domain_ids)
+       if (!iommu->domain_ids)
                return;
 
        spin_lock_irqsave(&device_domain_lock, flags);
@@ -1892,15 +1842,8 @@ static void disable_dmar_iommu(struct intel_iommu *iommu)
 
 static void free_dmar_iommu(struct intel_iommu *iommu)
 {
-       if ((iommu->domains) && (iommu->domain_ids)) {
-               int elems = ALIGN(cap_ndoms(iommu->cap), 256) >> 8;
-               int i;
-
-               for (i = 0; i < elems; i++)
-                       kfree(iommu->domains[i]);
-               kfree(iommu->domains);
+       if (iommu->domain_ids) {
                bitmap_free(iommu->domain_ids);
-               iommu->domains = NULL;
                iommu->domain_ids = NULL;
        }
 
@@ -1978,11 +1921,8 @@ static int domain_attach_iommu(struct dmar_domain *domain,
                }
 
                set_bit(num, iommu->domain_ids);
-               set_iommu_domain(iommu, num, domain);
-
                domain->iommu_did[iommu->seq_id] = num;
                domain->nid                      = iommu->node;
-
                domain_update_iommu_cap(domain);
        }
 
@@ -2001,8 +1941,6 @@ static void domain_detach_iommu(struct dmar_domain *domain,
        if (domain->iommu_refcnt[iommu->seq_id] == 0) {
                num = domain->iommu_did[iommu->seq_id];
                clear_bit(num, iommu->domain_ids);
-               set_iommu_domain(iommu, num, NULL);
-
                domain_update_iommu_cap(domain);
                domain->iommu_did[iommu->seq_id] = 0;
        }

diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index 5cfda90b2cca3a21ab02d2ade42b57c999d8c26f..8c7591b5f3e2445db2415c089aa593451ceaf297 100644 (file)
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -578,7 +578,6 @@ struct intel_iommu {
 
 #ifdef CONFIG_INTEL_IOMMU
        unsigned long   *domain_ids; /* bitmap of domains */
-       struct dmar_domain ***domains; /* ptr to domains */
        spinlock_t      lock; /* protect context, domain ids */
        struct root_entry *root_entry; /* virtual address */