[Patch Part3 V4 20/21] iommu/vt-d: Enhance intel-iommu driver to support DMAR unit hotplug

Jiang Liu
2014-07-11T06:18:51Z

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

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
---
drivers/iommu/intel-iommu.c | 206 +++++++++++++++++++++++++++++++------------
1 file changed, 151 insertions(+), 55 deletions(-)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index d35141ab62c3..fb805caf9774 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -1125,8 +1125,11 @@ 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);

@@ -1466,7 +1469,7 @@ 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;
@@ -1490,11 +1493,16 @@ 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;

@@ -2677,6 +2685,41 @@ 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;
@@ -2705,6 +2748,10 @@ 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) {
@@ -2733,58 +2780,14 @@ 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;
@@ -2870,8 +2873,10 @@ 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);
@@ -3777,9 +3782,100 @@ 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)
--
1.7.10.4