iommu/vt-d: Enhance intel-iommu driver to support DMAR unit hotplug

Implement required callback functions for intel-iommu driver
to support DMAR unit hotplug.

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>

1 files changed, 151 insertions, 55 deletions

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 7c49ab51904f..99bf651234a6 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -1127,8 +1127,11 @@ static int iommu_alloc_root_entry(struct intel_iommu *iommu)
         unsigned long flags;
 
         root = (struct root_entry *)alloc_pgtable_page(iommu->node);
-        if (!root)
+        if (!root) {
+                pr_err("IOMMU: allocating root entry for %s failed\n",
+                        iommu->name);
                 return -ENOMEM;
+        }
 
         __iommu_flush_cache(iommu, root, ROOT_SIZE);
 
@@ -1468,7 +1471,7 @@ static int iommu_init_domains(struct intel_iommu *iommu)
         return 0;
 }
 
-static void free_dmar_iommu(struct intel_iommu *iommu)
+static void disable_dmar_iommu(struct intel_iommu *iommu)
 {
         struct dmar_domain *domain;
         int i;
@@ -1492,11 +1495,16 @@ static void free_dmar_iommu(struct intel_iommu *iommu)
 
         if (iommu->gcmd & DMA_GCMD_TE)
                 iommu_disable_translation(iommu);
+}
 
-        kfree(iommu->domains);
-        kfree(iommu->domain_ids);
-        iommu->domains = NULL;
-        iommu->domain_ids = NULL;
+static void free_dmar_iommu(struct intel_iommu *iommu)
+{
+        if ((iommu->domains) && (iommu->domain_ids)) {
+                kfree(iommu->domains);
+                kfree(iommu->domain_ids);
+                iommu->domains = NULL;
+                iommu->domain_ids = NULL;
+        }
 
         g_iommus[iommu->seq_id] = NULL;
 
@@ -2703,6 +2711,41 @@ static int __init iommu_prepare_static_identity_mapping(int hw)
         return 0;
 }
 
+static void intel_iommu_init_qi(struct intel_iommu *iommu)
+{
+        /*
+         * Start from the sane iommu hardware state.
+         * If the queued invalidation is already initialized by us
+         * (for example, while enabling interrupt-remapping) then
+         * we got the things already rolling from a sane state.
+         */
+        if (!iommu->qi) {
+                /*
+                 * Clear any previous faults.
+                 */
+                dmar_fault(-1, iommu);
+                /*
+                 * Disable queued invalidation if supported and already enabled
+                 * before OS handover.
+                 */
+                dmar_disable_qi(iommu);
+        }
+
+        if (dmar_enable_qi(iommu)) {
+                /*
+                 * Queued Invalidate not enabled, use Register Based Invalidate
+                 */
+                iommu->flush.flush_context = __iommu_flush_context;
+                iommu->flush.flush_iotlb = __iommu_flush_iotlb;
+                pr_info("IOMMU: %s using Register based invalidation\n",
+                        iommu->name);
+        } else {
+                iommu->flush.flush_context = qi_flush_context;
+                iommu->flush.flush_iotlb = qi_flush_iotlb;
+                pr_info("IOMMU: %s using Queued invalidation\n", iommu->name);
+        }
+}
+
 static int __init init_dmars(void)
 {
         struct dmar_drhd_unit *drhd;
@@ -2731,6 +2774,10 @@ static int __init init_dmars(void)
                           DMAR_UNITS_SUPPORTED);
         }
 
+        /* Preallocate enough resources for IOMMU hot-addition */
+        if (g_num_of_iommus < DMAR_UNITS_SUPPORTED)
+                g_num_of_iommus = DMAR_UNITS_SUPPORTED;
+
         g_iommus = kcalloc(g_num_of_iommus, sizeof(struct intel_iommu *),
                         GFP_KERNEL);
         if (!g_iommus) {
@@ -2759,58 +2806,14 @@ static int __init init_dmars(void)
                  * among all IOMMU's. Need to Split it later.
                  */
                 ret = iommu_alloc_root_entry(iommu);
-                if (ret) {
-                        printk(KERN_ERR "IOMMU: allocate root entry failed\n");
+                if (ret)
                         goto free_iommu;
-                }
                 if (!ecap_pass_through(iommu->ecap))
                         hw_pass_through = 0;
         }
 
-        /*
-         * Start from the sane iommu hardware state.
-         */
-        for_each_active_iommu(iommu, drhd) {
-                /*
-                 * If the queued invalidation is already initialized by us
-                 * (for example, while enabling interrupt-remapping) then
-                 * we got the things already rolling from a sane state.
-                 */
-                if (iommu->qi)
-                        continue;
-
-                /*
-                 * Clear any previous faults.
-                 */
-                dmar_fault(-1, iommu);
-                /*
-                 * Disable queued invalidation if supported and already enabled
-                 * before OS handover.
-                 */
-                dmar_disable_qi(iommu);
-        }
-
-        for_each_active_iommu(iommu, drhd) {
-                if (dmar_enable_qi(iommu)) {
-                        /*
-                         * Queued Invalidate not enabled, use Register Based
-                         * Invalidate
-                         */
-                        iommu->flush.flush_context = __iommu_flush_context;
-                        iommu->flush.flush_iotlb = __iommu_flush_iotlb;
-                        printk(KERN_INFO "IOMMU %d 0x%Lx: using Register based "
-                               "invalidation\n",
-                                iommu->seq_id,
-                               (unsigned long long)drhd->reg_base_addr);
-                } else {
-                        iommu->flush.flush_context = qi_flush_context;
-                        iommu->flush.flush_iotlb = qi_flush_iotlb;
-                        printk(KERN_INFO "IOMMU %d 0x%Lx: using Queued "
-                               "invalidation\n",
-                                iommu->seq_id,
-                               (unsigned long long)drhd->reg_base_addr);
-                }
-        }
+        for_each_active_iommu(iommu, drhd)
+                intel_iommu_init_qi(iommu);
 
         if (iommu_pass_through)
                 iommu_identity_mapping |= IDENTMAP_ALL;
@@ -2896,8 +2899,10 @@ static int __init init_dmars(void)
         return 0;
 
 free_iommu:
-        for_each_active_iommu(iommu, drhd)
+        for_each_active_iommu(iommu, drhd) {
+                disable_dmar_iommu(iommu);
                 free_dmar_iommu(iommu);
+        }
         kfree(deferred_flush);
 free_g_iommus:
         kfree(g_iommus);
@@ -3803,9 +3808,100 @@ int dmar_check_one_atsr(struct acpi_dmar_header *hdr, void *arg)
         return 0;
 }
 
+static int intel_iommu_add(struct dmar_drhd_unit *dmaru)
+{
+        int sp, ret = 0;
+        struct intel_iommu *iommu = dmaru->iommu;
+
+        if (g_iommus[iommu->seq_id])
+                return 0;
+
+        if (hw_pass_through && !ecap_pass_through(iommu->ecap)) {
+                pr_warn("IOMMU: %s doesn't support hardware pass through.\n",
+                        iommu->name);
+                return -ENXIO;
+        }
+        if (!ecap_sc_support(iommu->ecap) &&
+            domain_update_iommu_snooping(iommu)) {
+                pr_warn("IOMMU: %s doesn't support snooping.\n",
+                        iommu->name);
+                return -ENXIO;
+        }
+        sp = domain_update_iommu_superpage(iommu) - 1;
+        if (sp >= 0 && !(cap_super_page_val(iommu->cap) & (1 << sp))) {
+                pr_warn("IOMMU: %s doesn't support large page.\n",
+                        iommu->name);
+                return -ENXIO;
+        }
+
+        /*
+         * Disable translation if already enabled prior to OS handover.
+         */
+        if (iommu->gcmd & DMA_GCMD_TE)
+                iommu_disable_translation(iommu);
+
+        g_iommus[iommu->seq_id] = iommu;
+        ret = iommu_init_domains(iommu);
+        if (ret == 0)
+                ret = iommu_alloc_root_entry(iommu);
+        if (ret)
+                goto out;
+
+        if (dmaru->ignored) {
+                /*
+                 * we always have to disable PMRs or DMA may fail on this device
+                 */
+                if (force_on)
+                        iommu_disable_protect_mem_regions(iommu);
+                return 0;
+        }
+
+        intel_iommu_init_qi(iommu);
+        iommu_flush_write_buffer(iommu);
+        ret = dmar_set_interrupt(iommu);
+        if (ret)
+                goto disable_iommu;
+
+        iommu_set_root_entry(iommu);
+        iommu->flush.flush_context(iommu, 0, 0, 0, DMA_CCMD_GLOBAL_INVL);
+        iommu->flush.flush_iotlb(iommu, 0, 0, 0, DMA_TLB_GLOBAL_FLUSH);
+        iommu_enable_translation(iommu);
+
+        if (si_domain) {
+                ret = iommu_attach_domain(si_domain, iommu);
+                if (ret < 0 || si_domain->id != ret)
+                        goto disable_iommu;
+                domain_attach_iommu(si_domain, iommu);
+        }
+
+        iommu_disable_protect_mem_regions(iommu);
+        return 0;
+
+disable_iommu:
+        disable_dmar_iommu(iommu);
+out:
+        free_dmar_iommu(iommu);
+        return ret;
+}
+
 int dmar_iommu_hotplug(struct dmar_drhd_unit *dmaru, bool insert)
 {
-        return intel_iommu_enabled ? -ENOSYS : 0;
+        int ret = 0;
+        struct intel_iommu *iommu = dmaru->iommu;
+
+        if (!intel_iommu_enabled)
+                return 0;
+        if (iommu == NULL)
+                return -EINVAL;
+
+        if (insert) {
+                ret = intel_iommu_add(dmaru);
+        } else {
+                disable_dmar_iommu(iommu);
+                free_dmar_iommu(iommu);
+        }
+
+        return ret;
 }
 
 static void intel_iommu_free_dmars(void)