2 files changed, 240 insertions, 259 deletions

diff --git a/Documentation/devicetree/bindings/iommu/arm,smmu.txt b/Documentation/devicetree/bindings/iommu/arm,smmu.txt
index f284b99402bc..2d0f7cd867ea 100644
--- a/Documentation/devicetree/bindings/iommu/arm,smmu.txt
+++ b/Documentation/devicetree/bindings/iommu/arm,smmu.txt
@@ -42,12 +42,6 @@ conditions.
 
 ** System MMU optional properties:
 
-- smmu-parent   : When multiple SMMUs are chained together, this
-                  property can be used to provide a phandle to the
-                  parent SMMU (that is the next SMMU on the path going
-                  from the mmu-masters towards memory) node for this
-                  SMMU.
-
 - calxeda,smmu-secure-config-access : Enable proper handling of buggy
                   implementations that always use secure access to
                   SMMU configuration registers. In this case non-secure
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 1599354e974d..f3f66416e252 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -39,6 +39,7 @@
 #include <linux/mm.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/pci.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
@@ -316,9 +317,9 @@
 #define FSR_AFF                         (1 << 2)
 #define FSR_TF                          (1 << 1)
 
-#define FSR_IGN                         (FSR_AFF | FSR_ASF | FSR_TLBMCF |       \
-                                         FSR_TLBLKF)
-#define FSR_FAULT                       (FSR_MULTI | FSR_SS | FSR_UUT |         \
+#define FSR_IGN                         (FSR_AFF | FSR_ASF | \
+                                         FSR_TLBMCF | FSR_TLBLKF)
+#define FSR_FAULT                       (FSR_MULTI | FSR_SS | FSR_UUT | \
                                          FSR_EF | FSR_PF | FSR_TF | FSR_IGN)
 
 #define FSYNR0_WNR                      (1 << 4)
@@ -329,27 +330,20 @@ struct arm_smmu_smr {
         u16                             id;
 };
 
-struct arm_smmu_master {
-        struct device_node              *of_node;
-
-        /*
-         * The following is specific to the master's position in the
-         * SMMU chain.
-         */
-        struct rb_node                  node;
+struct arm_smmu_master_cfg {
         int                             num_streamids;
         u16                             streamids[MAX_MASTER_STREAMIDS];
-
-        /*
-         * We only need to allocate these on the root SMMU, as we
-         * configure unmatched streams to bypass translation.
-         */
         struct arm_smmu_smr             *smrs;
 };
 
+struct arm_smmu_master {
+        struct device_node              *of_node;
+        struct rb_node                  node;
+        struct arm_smmu_master_cfg      cfg;
+};
+
 struct arm_smmu_device {
         struct device                   *dev;
-        struct device_node              *parent_of_node;
 
         void __iomem                    *base;
         unsigned long                   size;
@@ -387,7 +381,6 @@ struct arm_smmu_device {
 };
 
 struct arm_smmu_cfg {
-        struct arm_smmu_device          *smmu;
         u8                              cbndx;
         u8                              irptndx;
         u32                             cbar;
@@ -399,15 +392,8 @@ struct arm_smmu_cfg {
 #define ARM_SMMU_CB_VMID(cfg)           ((cfg)->cbndx + 1)
 
 struct arm_smmu_domain {
-        /*
-         * A domain can span across multiple, chained SMMUs and requires
-         * all devices within the domain to follow the same translation
-         * path.
-         */
-        struct arm_smmu_device          *leaf_smmu;
-        struct arm_smmu_cfg             root_cfg;
-        phys_addr_t                     output_mask;
-
+        struct arm_smmu_device          *smmu;
+        struct arm_smmu_cfg             cfg;
         spinlock_t                      lock;
 };
 
@@ -419,7 +405,7 @@ struct arm_smmu_option_prop {
         const char *prop;
 };
 
-static struct arm_smmu_option_prop arm_smmu_options [] = {
+static struct arm_smmu_option_prop arm_smmu_options[] = {
         { ARM_SMMU_OPT_SECURE_CFG_ACCESS, "calxeda,smmu-secure-config-access" },
         { 0, NULL},
 };
@@ -427,6 +413,7 @@ static struct arm_smmu_option_prop arm_smmu_options [] = {
 static void parse_driver_options(struct arm_smmu_device *smmu)
 {
         int i = 0;
+
         do {
                 if (of_property_read_bool(smmu->dev->of_node,
                                                 arm_smmu_options[i].prop)) {
@@ -437,6 +424,19 @@ static void parse_driver_options(struct arm_smmu_device *smmu)
         } while (arm_smmu_options[++i].opt);
 }
 
+static struct device *dev_get_master_dev(struct device *dev)
+{
+        if (dev_is_pci(dev)) {
+                struct pci_bus *bus = to_pci_dev(dev)->bus;
+
+                while (!pci_is_root_bus(bus))
+                        bus = bus->parent;
+                return bus->bridge->parent;
+        }
+
+        return dev;
+}
+
 static struct arm_smmu_master *find_smmu_master(struct arm_smmu_device *smmu,
                                                 struct device_node *dev_node)
 {
@@ -444,6 +444,7 @@ static struct arm_smmu_master *find_smmu_master(struct arm_smmu_device *smmu,
 
         while (node) {
                 struct arm_smmu_master *master;
+
                 master = container_of(node, struct arm_smmu_master, node);
 
                 if (dev_node < master->of_node)
@@ -457,6 +458,18 @@ static struct arm_smmu_master *find_smmu_master(struct arm_smmu_device *smmu,
         return NULL;
 }
 
+static struct arm_smmu_master_cfg *
+find_smmu_master_cfg(struct arm_smmu_device *smmu, struct device *dev)
+{
+        struct arm_smmu_master *master;
+
+        if (dev_is_pci(dev))
+                return dev->archdata.iommu;
+
+        master = find_smmu_master(smmu, dev->of_node);
+        return master ? &master->cfg : NULL;
+}
+
 static int insert_smmu_master(struct arm_smmu_device *smmu,
                               struct arm_smmu_master *master)
 {
@@ -465,8 +478,8 @@ static int insert_smmu_master(struct arm_smmu_device *smmu,
         new = &smmu->masters.rb_node;
         parent = NULL;
         while (*new) {
-                struct arm_smmu_master *this;
-                this = container_of(*new, struct arm_smmu_master, node);
+                struct arm_smmu_master *this
+                        = container_of(*new, struct arm_smmu_master, node);
 
                 parent = *new;
                 if (master->of_node < this->of_node)
@@ -508,33 +521,30 @@ static int register_smmu_master(struct arm_smmu_device *smmu,
         if (!master)
                 return -ENOMEM;
 
-        master->of_node         = masterspec->np;
-        master->num_streamids   = masterspec->args_count;
+        master->of_node                 = masterspec->np;
+        master->cfg.num_streamids       = masterspec->args_count;
 
-        for (i = 0; i < master->num_streamids; ++i)
-                master->streamids[i] = masterspec->args[i];
+        for (i = 0; i < master->cfg.num_streamids; ++i)
+                master->cfg.streamids[i] = masterspec->args[i];
 
         return insert_smmu_master(smmu, master);
 }
 
-static struct arm_smmu_device *find_parent_smmu(struct arm_smmu_device *smmu)
+static struct arm_smmu_device *find_smmu_for_device(struct device *dev)
 {
-        struct arm_smmu_device *parent;
-
-        if (!smmu->parent_of_node)
-                return NULL;
+        struct arm_smmu_device *smmu;
+        struct arm_smmu_master *master = NULL;
+        struct device_node *dev_node = dev_get_master_dev(dev)->of_node;
 
         spin_lock(&arm_smmu_devices_lock);
-        list_for_each_entry(parent, &arm_smmu_devices, list)
-                if (parent->dev->of_node == smmu->parent_of_node)
-                        goto out_unlock;
-
-        parent = NULL;
-        dev_warn(smmu->dev,
-                 "Failed to find SMMU parent despite parent in DT\n");
-out_unlock:
+        list_for_each_entry(smmu, &arm_smmu_devices, list) {
+                master = find_smmu_master(smmu, dev_node);
+                if (master)
+                        break;
+        }
         spin_unlock(&arm_smmu_devices_lock);
-        return parent;
+
+        return master ? smmu : NULL;
 }
 
 static int __arm_smmu_alloc_bitmap(unsigned long *map, int start, int end)
@@ -574,9 +584,10 @@ static void arm_smmu_tlb_sync(struct arm_smmu_device *smmu)
         }
 }
 
-static void arm_smmu_tlb_inv_context(struct arm_smmu_cfg *cfg)
+static void arm_smmu_tlb_inv_context(struct arm_smmu_domain *smmu_domain)
 {
-        struct arm_smmu_device *smmu = cfg->smmu;
+        struct arm_smmu_cfg *cfg = &smmu_domain->cfg;
+        struct arm_smmu_device *smmu = smmu_domain->smmu;
         void __iomem *base = ARM_SMMU_GR0(smmu);
         bool stage1 = cfg->cbar != CBAR_TYPE_S2_TRANS;
 
@@ -600,11 +611,11 @@ static irqreturn_t arm_smmu_context_fault(int irq, void *dev)
         unsigned long iova;
         struct iommu_domain *domain = dev;
         struct arm_smmu_domain *smmu_domain = domain->priv;
-        struct arm_smmu_cfg *root_cfg = &smmu_domain->root_cfg;
-        struct arm_smmu_device *smmu = root_cfg->smmu;
+        struct arm_smmu_cfg *cfg = &smmu_domain->cfg;
+        struct arm_smmu_device *smmu = smmu_domain->smmu;
         void __iomem *cb_base;
 
-        cb_base = ARM_SMMU_CB_BASE(smmu) + ARM_SMMU_CB(smmu, root_cfg->cbndx);
+        cb_base = ARM_SMMU_CB_BASE(smmu) + ARM_SMMU_CB(smmu, cfg->cbndx);
         fsr = readl_relaxed(cb_base + ARM_SMMU_CB_FSR);
 
         if (!(fsr & FSR_FAULT))
@@ -631,7 +642,7 @@ static irqreturn_t arm_smmu_context_fault(int irq, void *dev)
         } else {
                 dev_err_ratelimited(smmu->dev,
                     "Unhandled context fault: iova=0x%08lx, fsynr=0x%x, cb=%d\n",
-                    iova, fsynr, root_cfg->cbndx);
+                    iova, fsynr, cfg->cbndx);
                 ret = IRQ_NONE;
                 resume = RESUME_TERMINATE;
         }
@@ -696,19 +707,19 @@ static void arm_smmu_init_context_bank(struct arm_smmu_domain *smmu_domain)
 {
         u32 reg;
         bool stage1;
-        struct arm_smmu_cfg *root_cfg = &smmu_domain->root_cfg;
-        struct arm_smmu_device *smmu = root_cfg->smmu;
+        struct arm_smmu_cfg *cfg = &smmu_domain->cfg;
+        struct arm_smmu_device *smmu = smmu_domain->smmu;
         void __iomem *cb_base, *gr0_base, *gr1_base;
 
         gr0_base = ARM_SMMU_GR0(smmu);
         gr1_base = ARM_SMMU_GR1(smmu);
-        stage1 = root_cfg->cbar != CBAR_TYPE_S2_TRANS;
-        cb_base = ARM_SMMU_CB_BASE(smmu) + ARM_SMMU_CB(smmu, root_cfg->cbndx);
+        stage1 = cfg->cbar != CBAR_TYPE_S2_TRANS;
+        cb_base = ARM_SMMU_CB_BASE(smmu) + ARM_SMMU_CB(smmu, cfg->cbndx);
 
         /* CBAR */
-        reg = root_cfg->cbar;
+        reg = cfg->cbar;
         if (smmu->version == 1)
-              reg |= root_cfg->irptndx << CBAR_IRPTNDX_SHIFT;
+                reg |= cfg->irptndx << CBAR_IRPTNDX_SHIFT;
 
         /*
          * Use the weakest shareability/memory types, so they are
@@ -718,9 +729,9 @@ static void arm_smmu_init_context_bank(struct arm_smmu_domain *smmu_domain)
                 reg |= (CBAR_S1_BPSHCFG_NSH << CBAR_S1_BPSHCFG_SHIFT) |
                         (CBAR_S1_MEMATTR_WB << CBAR_S1_MEMATTR_SHIFT);
         } else {
-                reg |= ARM_SMMU_CB_VMID(root_cfg) << CBAR_VMID_SHIFT;
+                reg |= ARM_SMMU_CB_VMID(cfg) << CBAR_VMID_SHIFT;
         }
-        writel_relaxed(reg, gr1_base + ARM_SMMU_GR1_CBAR(root_cfg->cbndx));
+        writel_relaxed(reg, gr1_base + ARM_SMMU_GR1_CBAR(cfg->cbndx));
 
         if (smmu->version > 1) {
                 /* CBA2R */
@@ -730,7 +741,7 @@ static void arm_smmu_init_context_bank(struct arm_smmu_domain *smmu_domain)
                 reg = CBA2R_RW64_32BIT;
 #endif
                 writel_relaxed(reg,
-                               gr1_base + ARM_SMMU_GR1_CBA2R(root_cfg->cbndx));
+                               gr1_base + ARM_SMMU_GR1_CBA2R(cfg->cbndx));
 
                 /* TTBCR2 */
                 switch (smmu->input_size) {
@@ -780,13 +791,13 @@ static void arm_smmu_init_context_bank(struct arm_smmu_domain *smmu_domain)
         }
 
         /* TTBR0 */
-        arm_smmu_flush_pgtable(smmu, root_cfg->pgd,
+        arm_smmu_flush_pgtable(smmu, cfg->pgd,
                                PTRS_PER_PGD * sizeof(pgd_t));
-        reg = __pa(root_cfg->pgd);
+        reg = __pa(cfg->pgd);
         writel_relaxed(reg, cb_base + ARM_SMMU_CB_TTBR0_LO);
-        reg = (phys_addr_t)__pa(root_cfg->pgd) >> 32;
+        reg = (phys_addr_t)__pa(cfg->pgd) >> 32;
         if (stage1)
-                reg |= ARM_SMMU_CB_ASID(root_cfg) << TTBRn_HI_ASID_SHIFT;
+                reg |= ARM_SMMU_CB_ASID(cfg) << TTBRn_HI_ASID_SHIFT;
         writel_relaxed(reg, cb_base + ARM_SMMU_CB_TTBR0_HI);
 
         /*
@@ -800,6 +811,8 @@ static void arm_smmu_init_context_bank(struct arm_smmu_domain *smmu_domain)
                         reg = TTBCR_TG0_64K;
 
                 if (!stage1) {
+                        reg |= (64 - smmu->s1_output_size) << TTBCR_T0SZ_SHIFT;
+
                         switch (smmu->s2_output_size) {
                         case 32:
                                 reg |= (TTBCR2_ADDR_32 << TTBCR_PASIZE_SHIFT);
@@ -821,7 +834,7 @@ static void arm_smmu_init_context_bank(struct arm_smmu_domain *smmu_domain)
                                 break;
                         }
                 } else {
-                        reg |= (64 - smmu->s1_output_size) << TTBCR_T0SZ_SHIFT;
+                        reg |= (64 - smmu->input_size) << TTBCR_T0SZ_SHIFT;
                 }
         } else {
                 reg = 0;
@@ -853,44 +866,25 @@ static void arm_smmu_init_context_bank(struct arm_smmu_domain *smmu_domain)
 }
 
 static int arm_smmu_init_domain_context(struct iommu_domain *domain,
-                                        struct device *dev)
+                                        struct arm_smmu_device *smmu)
 {
         int irq, ret, start;
         struct arm_smmu_domain *smmu_domain = domain->priv;
-        struct arm_smmu_cfg *root_cfg = &smmu_domain->root_cfg;
-        struct arm_smmu_device *smmu, *parent;
-
-        /*
-         * Walk the SMMU chain to find the root device for this chain.
-         * We assume that no masters have translations which terminate
-         * early, and therefore check that the root SMMU does indeed have
-         * a StreamID for the master in question.
-         */
-        parent = dev->archdata.iommu;
-        smmu_domain->output_mask = -1;
-        do {
-                smmu = parent;
-                smmu_domain->output_mask &= (1ULL << smmu->s2_output_size) - 1;
-        } while ((parent = find_parent_smmu(smmu)));
-
-        if (!find_smmu_master(smmu, dev->of_node)) {
-                dev_err(dev, "unable to find root SMMU for device\n");
-                return -ENODEV;
-        }
+        struct arm_smmu_cfg *cfg = &smmu_domain->cfg;
 
         if (smmu->features & ARM_SMMU_FEAT_TRANS_NESTED) {
                 /*
                  * We will likely want to change this if/when KVM gets
                  * involved.
                  */
-                root_cfg->cbar = CBAR_TYPE_S1_TRANS_S2_BYPASS;
+                cfg->cbar = CBAR_TYPE_S1_TRANS_S2_BYPASS;
                 start = smmu->num_s2_context_banks;
-        } else if (smmu->features & ARM_SMMU_FEAT_TRANS_S2) {
-                root_cfg->cbar = CBAR_TYPE_S2_TRANS;
-                start = 0;
-        } else {
-                root_cfg->cbar = CBAR_TYPE_S1_TRANS_S2_BYPASS;
+        } else if (smmu->features & ARM_SMMU_FEAT_TRANS_S1) {
+                cfg->cbar = CBAR_TYPE_S1_TRANS_S2_BYPASS;
                 start = smmu->num_s2_context_banks;
+        } else {
+                cfg->cbar = CBAR_TYPE_S2_TRANS;
+                start = 0;
         }
 
         ret = __arm_smmu_alloc_bitmap(smmu->context_map, start,
@@ -898,38 +892,38 @@ static int arm_smmu_init_domain_context(struct iommu_domain *domain,
         if (IS_ERR_VALUE(ret))
                 return ret;
 
-        root_cfg->cbndx = ret;
+        cfg->cbndx = ret;
         if (smmu->version == 1) {
-                root_cfg->irptndx = atomic_inc_return(&smmu->irptndx);
-                root_cfg->irptndx %= smmu->num_context_irqs;
+                cfg->irptndx = atomic_inc_return(&smmu->irptndx);
+                cfg->irptndx %= smmu->num_context_irqs;
         } else {
-                root_cfg->irptndx = root_cfg->cbndx;
+                cfg->irptndx = cfg->cbndx;
         }
 
-        irq = smmu->irqs[smmu->num_global_irqs + root_cfg->irptndx];
+        irq = smmu->irqs[smmu->num_global_irqs + cfg->irptndx];
         ret = request_irq(irq, arm_smmu_context_fault, IRQF_SHARED,
                           "arm-smmu-context-fault", domain);
         if (IS_ERR_VALUE(ret)) {
                 dev_err(smmu->dev, "failed to request context IRQ %d (%u)\n",
-                        root_cfg->irptndx, irq);
-                root_cfg->irptndx = INVALID_IRPTNDX;
+                        cfg->irptndx, irq);
+                cfg->irptndx = INVALID_IRPTNDX;
                 goto out_free_context;
         }
 
-        root_cfg->smmu = smmu;
+        smmu_domain->smmu = smmu;
         arm_smmu_init_context_bank(smmu_domain);
-        return ret;
+        return 0;
 
 out_free_context:
-        __arm_smmu_free_bitmap(smmu->context_map, root_cfg->cbndx);
+        __arm_smmu_free_bitmap(smmu->context_map, cfg->cbndx);
         return ret;
 }
 
 static void arm_smmu_destroy_domain_context(struct iommu_domain *domain)
 {
         struct arm_smmu_domain *smmu_domain = domain->priv;
-        struct arm_smmu_cfg *root_cfg = &smmu_domain->root_cfg;
-        struct arm_smmu_device *smmu = root_cfg->smmu;
+        struct arm_smmu_device *smmu = smmu_domain->smmu;
+        struct arm_smmu_cfg *cfg = &smmu_domain->cfg;
         void __iomem *cb_base;
         int irq;
 
@@ -937,16 +931,16 @@ static void arm_smmu_destroy_domain_context(struct iommu_domain *domain)
                 return;
 
         /* Disable the context bank and nuke the TLB before freeing it. */
-        cb_base = ARM_SMMU_CB_BASE(smmu) + ARM_SMMU_CB(smmu, root_cfg->cbndx);
+        cb_base = ARM_SMMU_CB_BASE(smmu) + ARM_SMMU_CB(smmu, cfg->cbndx);
         writel_relaxed(0, cb_base + ARM_SMMU_CB_SCTLR);
-        arm_smmu_tlb_inv_context(root_cfg);
+        arm_smmu_tlb_inv_context(smmu_domain);
 
-        if (root_cfg->irptndx != INVALID_IRPTNDX) {
-                irq = smmu->irqs[smmu->num_global_irqs + root_cfg->irptndx];
+        if (cfg->irptndx != INVALID_IRPTNDX) {
+                irq = smmu->irqs[smmu->num_global_irqs + cfg->irptndx];
                 free_irq(irq, domain);
         }
 
-        __arm_smmu_free_bitmap(smmu->context_map, root_cfg->cbndx);
+        __arm_smmu_free_bitmap(smmu->context_map, cfg->cbndx);
 }
 
 static int arm_smmu_domain_init(struct iommu_domain *domain)
@@ -963,10 +957,10 @@ static int arm_smmu_domain_init(struct iommu_domain *domain)
         if (!smmu_domain)
                 return -ENOMEM;
 
-        pgd = kzalloc(PTRS_PER_PGD * sizeof(pgd_t), GFP_KERNEL);
+        pgd = kcalloc(PTRS_PER_PGD, sizeof(pgd_t), GFP_KERNEL);
         if (!pgd)
                 goto out_free_domain;
-        smmu_domain->root_cfg.pgd = pgd;
+        smmu_domain->cfg.pgd = pgd;
 
         spin_lock_init(&smmu_domain->lock);
         domain->priv = smmu_domain;
@@ -980,6 +974,7 @@ out_free_domain:
 static void arm_smmu_free_ptes(pmd_t *pmd)
 {
         pgtable_t table = pmd_pgtable(*pmd);
+
         pgtable_page_dtor(table);
         __free_page(table);
 }
@@ -1021,8 +1016,8 @@ static void arm_smmu_free_puds(pgd_t *pgd)
 static void arm_smmu_free_pgtables(struct arm_smmu_domain *smmu_domain)
 {
         int i;
-        struct arm_smmu_cfg *root_cfg = &smmu_domain->root_cfg;
-        pgd_t *pgd, *pgd_base = root_cfg->pgd;
+        struct arm_smmu_cfg *cfg = &smmu_domain->cfg;
+        pgd_t *pgd, *pgd_base = cfg->pgd;
 
         /*
          * Recursively free the page tables for this domain. We don't
@@ -1054,7 +1049,7 @@ static void arm_smmu_domain_destroy(struct iommu_domain *domain)
 }
 
 static int arm_smmu_master_configure_smrs(struct arm_smmu_device *smmu,
-                                          struct arm_smmu_master *master)
+                                          struct arm_smmu_master_cfg *cfg)
 {
         int i;
         struct arm_smmu_smr *smrs;
@@ -1063,18 +1058,18 @@ static int arm_smmu_master_configure_smrs(struct arm_smmu_device *smmu,
         if (!(smmu->features & ARM_SMMU_FEAT_STREAM_MATCH))
                 return 0;
 
-        if (master->smrs)
+        if (cfg->smrs)
                 return -EEXIST;
 
-        smrs = kmalloc(sizeof(*smrs) * master->num_streamids, GFP_KERNEL);
+        smrs = kmalloc_array(cfg->num_streamids, sizeof(*smrs), GFP_KERNEL);
         if (!smrs) {
-                dev_err(smmu->dev, "failed to allocate %d SMRs for master %s\n",
-                        master->num_streamids, master->of_node->name);
+                dev_err(smmu->dev, "failed to allocate %d SMRs\n",
+                        cfg->num_streamids);
                 return -ENOMEM;
         }
 
-        /* Allocate the SMRs on the root SMMU */
-        for (i = 0; i < master->num_streamids; ++i) {
+        /* Allocate the SMRs on the SMMU */
+        for (i = 0; i < cfg->num_streamids; ++i) {
                 int idx = __arm_smmu_alloc_bitmap(smmu->smr_map, 0,
                                                   smmu->num_mapping_groups);
                 if (IS_ERR_VALUE(idx)) {
@@ -1085,18 +1080,18 @@ static int arm_smmu_master_configure_smrs(struct arm_smmu_device *smmu,
                 smrs[i] = (struct arm_smmu_smr) {
                         .idx    = idx,
                         .mask   = 0, /* We don't currently share SMRs */
-                        .id     = master->streamids[i],
+                        .id     = cfg->streamids[i],
                 };
         }
 
         /* It worked! Now, poke the actual hardware */
-        for (i = 0; i < master->num_streamids; ++i) {
+        for (i = 0; i < cfg->num_streamids; ++i) {
                 u32 reg = SMR_VALID | smrs[i].id << SMR_ID_SHIFT |
                           smrs[i].mask << SMR_MASK_SHIFT;
                 writel_relaxed(reg, gr0_base + ARM_SMMU_GR0_SMR(smrs[i].idx));
         }
 
-        master->smrs = smrs;
+        cfg->smrs = smrs;
         return 0;
 
 err_free_smrs:
@@ -1107,68 +1102,55 @@ err_free_smrs:
 }
 
 static void arm_smmu_master_free_smrs(struct arm_smmu_device *smmu,
-                                      struct arm_smmu_master *master)
+                                      struct arm_smmu_master_cfg *cfg)
 {
         int i;
         void __iomem *gr0_base = ARM_SMMU_GR0(smmu);
-        struct arm_smmu_smr *smrs = master->smrs;
+        struct arm_smmu_smr *smrs = cfg->smrs;
 
         /* Invalidate the SMRs before freeing back to the allocator */
-        for (i = 0; i < master->num_streamids; ++i) {
+        for (i = 0; i < cfg->num_streamids; ++i) {
                 u8 idx = smrs[i].idx;
+
                 writel_relaxed(~SMR_VALID, gr0_base + ARM_SMMU_GR0_SMR(idx));
                 __arm_smmu_free_bitmap(smmu->smr_map, idx);
         }
 
-        master->smrs = NULL;
+        cfg->smrs = NULL;
         kfree(smrs);
 }
 
 static void arm_smmu_bypass_stream_mapping(struct arm_smmu_device *smmu,
-                                           struct arm_smmu_master *master)
+                                           struct arm_smmu_master_cfg *cfg)
 {
         int i;
         void __iomem *gr0_base = ARM_SMMU_GR0(smmu);
 
-        for (i = 0; i < master->num_streamids; ++i) {
-                u16 sid = master->streamids[i];
+        for (i = 0; i < cfg->num_streamids; ++i) {
+                u16 sid = cfg->streamids[i];
+
                 writel_relaxed(S2CR_TYPE_BYPASS,
                                gr0_base + ARM_SMMU_GR0_S2CR(sid));
         }
 }
 
 static int arm_smmu_domain_add_master(struct arm_smmu_domain *smmu_domain,
-                                      struct arm_smmu_master *master)
+                                      struct arm_smmu_master_cfg *cfg)
 {
         int i, ret;
-        struct arm_smmu_device *parent, *smmu = smmu_domain->root_cfg.smmu;
+        struct arm_smmu_device *smmu = smmu_domain->smmu;
         void __iomem *gr0_base = ARM_SMMU_GR0(smmu);
 
-        ret = arm_smmu_master_configure_smrs(smmu, master);
+        ret = arm_smmu_master_configure_smrs(smmu, cfg);
         if (ret)
                 return ret;
 
-        /* Bypass the leaves */
-        smmu = smmu_domain->leaf_smmu;
-        while ((parent = find_parent_smmu(smmu))) {
-                /*
-                 * We won't have a StreamID match for anything but the root
-                 * smmu, so we only need to worry about StreamID indexing,
-                 * where we must install bypass entries in the S2CRs.
-                 */
-                if (smmu->features & ARM_SMMU_FEAT_STREAM_MATCH)
-                        continue;
-
-                arm_smmu_bypass_stream_mapping(smmu, master);
-                smmu = parent;
-        }
-
-        /* Now we're at the root, time to point at our context bank */
-        for (i = 0; i < master->num_streamids; ++i) {
+        for (i = 0; i < cfg->num_streamids; ++i) {
                 u32 idx, s2cr;
-                idx = master->smrs ? master->smrs[i].idx : master->streamids[i];
+
+                idx = cfg->smrs ? cfg->smrs[i].idx : cfg->streamids[i];
                 s2cr = S2CR_TYPE_TRANS |
-                       (smmu_domain->root_cfg.cbndx << S2CR_CBNDX_SHIFT);
+                       (smmu_domain->cfg.cbndx << S2CR_CBNDX_SHIFT);
                 writel_relaxed(s2cr, gr0_base + ARM_SMMU_GR0_S2CR(idx));
         }
 
@@ -1176,58 +1158,57 @@ static int arm_smmu_domain_add_master(struct arm_smmu_domain *smmu_domain,
 }
 
 static void arm_smmu_domain_remove_master(struct arm_smmu_domain *smmu_domain,
-                                          struct arm_smmu_master *master)
+                                          struct arm_smmu_master_cfg *cfg)
 {
-        struct arm_smmu_device *smmu = smmu_domain->root_cfg.smmu;
+        struct arm_smmu_device *smmu = smmu_domain->smmu;
 
         /*
          * We *must* clear the S2CR first, because freeing the SMR means
          * that it can be re-allocated immediately.
          */
-        arm_smmu_bypass_stream_mapping(smmu, master);
-        arm_smmu_master_free_smrs(smmu, master);
+        arm_smmu_bypass_stream_mapping(smmu, cfg);
+        arm_smmu_master_free_smrs(smmu, cfg);
 }
 
 static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
 {
         int ret = -EINVAL;
         struct arm_smmu_domain *smmu_domain = domain->priv;
-        struct arm_smmu_device *device_smmu = dev->archdata.iommu;
-        struct arm_smmu_master *master;
+        struct arm_smmu_device *smmu;
+        struct arm_smmu_master_cfg *cfg;
         unsigned long flags;
 
-        if (!device_smmu) {
+        smmu = dev_get_master_dev(dev)->archdata.iommu;
+        if (!smmu) {
                 dev_err(dev, "cannot attach to SMMU, is it on the same bus?\n");
                 return -ENXIO;
         }
 
         /*
-         * Sanity check the domain. We don't currently support domains
-         * that cross between different SMMU chains.
+         * Sanity check the domain. We don't support domains across
+         * different SMMUs.
          */
         spin_lock_irqsave(&smmu_domain->lock, flags);
-        if (!smmu_domain->leaf_smmu) {
+        if (!smmu_domain->smmu) {
                 /* Now that we have a master, we can finalise the domain */
-                ret = arm_smmu_init_domain_context(domain, dev);
+                ret = arm_smmu_init_domain_context(domain, smmu);
                 if (IS_ERR_VALUE(ret))
                         goto err_unlock;
-
-                smmu_domain->leaf_smmu = device_smmu;
-        } else if (smmu_domain->leaf_smmu != device_smmu) {
+        } else if (smmu_domain->smmu != smmu) {
                 dev_err(dev,
                         "cannot attach to SMMU %s whilst already attached to domain on SMMU %s\n",
-                        dev_name(smmu_domain->leaf_smmu->dev),
-                        dev_name(device_smmu->dev));
+                        dev_name(smmu_domain->smmu->dev),
+                        dev_name(smmu->dev));
                 goto err_unlock;
         }
         spin_unlock_irqrestore(&smmu_domain->lock, flags);
 
         /* Looks ok, so add the device to the domain */
-        master = find_smmu_master(smmu_domain->leaf_smmu, dev->of_node);
-        if (!master)
+        cfg = find_smmu_master_cfg(smmu_domain->smmu, dev);
+        if (!cfg)
                 return -ENODEV;
 
-        return arm_smmu_domain_add_master(smmu_domain, master);
+        return arm_smmu_domain_add_master(smmu_domain, cfg);
 
 err_unlock:
         spin_unlock_irqrestore(&smmu_domain->lock, flags);
@@ -1237,11 +1218,11 @@ err_unlock:
 static void arm_smmu_detach_dev(struct iommu_domain *domain, struct device *dev)
 {
         struct arm_smmu_domain *smmu_domain = domain->priv;
-        struct arm_smmu_master *master;
+        struct arm_smmu_master_cfg *cfg;
 
-        master = find_smmu_master(smmu_domain->leaf_smmu, dev->of_node);
-        if (master)
-                arm_smmu_domain_remove_master(smmu_domain, master);
+        cfg = find_smmu_master_cfg(smmu_domain->smmu, dev);
+        if (cfg)
+                arm_smmu_domain_remove_master(smmu_domain, cfg);
 }
 
 static bool arm_smmu_pte_is_contiguous_range(unsigned long addr,
@@ -1261,6 +1242,7 @@ static int arm_smmu_alloc_init_pte(struct arm_smmu_device *smmu, pmd_t *pmd,
         if (pmd_none(*pmd)) {
                 /* Allocate a new set of tables */
                 pgtable_t table = alloc_page(GFP_ATOMIC|__GFP_ZERO);
+
                 if (!table)
                         return -ENOMEM;
 
@@ -1326,6 +1308,7 @@ static int arm_smmu_alloc_init_pte(struct arm_smmu_device *smmu, pmd_t *pmd,
          */
         do {
                 int i = 1;
+
                 pteval &= ~ARM_SMMU_PTE_CONT;
 
                 if (arm_smmu_pte_is_contiguous_range(addr, end)) {
@@ -1340,7 +1323,8 @@ static int arm_smmu_alloc_init_pte(struct arm_smmu_device *smmu, pmd_t *pmd,
                         idx &= ~(ARM_SMMU_PTE_CONT_ENTRIES - 1);
                         cont_start = pmd_page_vaddr(*pmd) + idx;
                         for (j = 0; j < ARM_SMMU_PTE_CONT_ENTRIES; ++j)
-                                pte_val(*(cont_start + j)) &= ~ARM_SMMU_PTE_CONT;
+                                pte_val(*(cont_start + j)) &=
+                                        ~ARM_SMMU_PTE_CONT;
 
                         arm_smmu_flush_pgtable(smmu, cont_start,
                                                sizeof(*pte) *
@@ -1429,12 +1413,12 @@ static int arm_smmu_handle_mapping(struct arm_smmu_domain *smmu_domain,
         int ret, stage;
         unsigned long end;
         phys_addr_t input_mask, output_mask;
-        struct arm_smmu_cfg *root_cfg = &smmu_domain->root_cfg;
-        pgd_t *pgd = root_cfg->pgd;
-        struct arm_smmu_device *smmu = root_cfg->smmu;
+        struct arm_smmu_device *smmu = smmu_domain->smmu;
+        struct arm_smmu_cfg *cfg = &smmu_domain->cfg;
+        pgd_t *pgd = cfg->pgd;
         unsigned long flags;
 
-        if (root_cfg->cbar == CBAR_TYPE_S2_TRANS) {
+        if (cfg->cbar == CBAR_TYPE_S2_TRANS) {
                 stage = 2;
                 output_mask = (1ULL << smmu->s2_output_size) - 1;
         } else {
@@ -1484,10 +1468,6 @@ static int arm_smmu_map(struct iommu_domain *domain, unsigned long iova,
         if (!smmu_domain)
                 return -ENODEV;
 
-        /* Check for silent address truncation up the SMMU chain. */
-        if ((phys_addr_t)iova & ~smmu_domain->output_mask)
-                return -ERANGE;
-
         return arm_smmu_handle_mapping(smmu_domain, iova, paddr, size, prot);
 }
 
@@ -1498,7 +1478,7 @@ static size_t arm_smmu_unmap(struct iommu_domain *domain, unsigned long iova,
         struct arm_smmu_domain *smmu_domain = domain->priv;
 
         ret = arm_smmu_handle_mapping(smmu_domain, iova, 0, size, 0);
-        arm_smmu_tlb_inv_context(&smmu_domain->root_cfg);
+        arm_smmu_tlb_inv_context(smmu_domain);
         return ret ? 0 : size;
 }
 
@@ -1510,9 +1490,9 @@ static phys_addr_t arm_smmu_iova_to_phys(struct iommu_domain *domain,
         pmd_t pmd;
         pte_t pte;
         struct arm_smmu_domain *smmu_domain = domain->priv;
-        struct arm_smmu_cfg *root_cfg = &smmu_domain->root_cfg;
+        struct arm_smmu_cfg *cfg = &smmu_domain->cfg;
 
-        pgdp = root_cfg->pgd;
+        pgdp = cfg->pgd;
         if (!pgdp)
                 return 0;
 
@@ -1538,19 +1518,29 @@ static phys_addr_t arm_smmu_iova_to_phys(struct iommu_domain *domain,
 static int arm_smmu_domain_has_cap(struct iommu_domain *domain,
                                    unsigned long cap)
 {
-        unsigned long caps = 0;
         struct arm_smmu_domain *smmu_domain = domain->priv;
+        struct arm_smmu_device *smmu = smmu_domain->smmu;
+        u32 features = smmu ? smmu->features : 0;
+
+        switch (cap) {
+        case IOMMU_CAP_CACHE_COHERENCY:
+                return features & ARM_SMMU_FEAT_COHERENT_WALK;
+        case IOMMU_CAP_INTR_REMAP:
+                return 1; /* MSIs are just memory writes */
+        default:
+                return 0;
+        }
+}
 
-        if (smmu_domain->root_cfg.smmu->features & ARM_SMMU_FEAT_COHERENT_WALK)
-                caps |= IOMMU_CAP_CACHE_COHERENCY;
-
-        return !!(cap & caps);
+static int __arm_smmu_get_pci_sid(struct pci_dev *pdev, u16 alias, void *data)
+{
+        *((u16 *)data) = alias;
+        return 0; /* Continue walking */
 }
 
 static int arm_smmu_add_device(struct device *dev)
 {
-        struct arm_smmu_device *child, *parent, *smmu;
-        struct arm_smmu_master *master = NULL;
+        struct arm_smmu_device *smmu;
         struct iommu_group *group;
         int ret;
 
@@ -1559,35 +1549,8 @@ static int arm_smmu_add_device(struct device *dev)
                 return -EINVAL;
         }
 
-        spin_lock(&arm_smmu_devices_lock);
-        list_for_each_entry(parent, &arm_smmu_devices, list) {
-                smmu = parent;
-
-                /* Try to find a child of the current SMMU. */
-                list_for_each_entry(child, &arm_smmu_devices, list) {
-                        if (child->parent_of_node == parent->dev->of_node) {
-                                /* Does the child sit above our master? */
-                                master = find_smmu_master(child, dev->of_node);
-                                if (master) {
-                                        smmu = NULL;
-                                        break;
-                                }
-                        }
-                }
-
-                /* We found some children, so keep searching. */
-                if (!smmu) {
-                        master = NULL;
-                        continue;
-                }
-
-                master = find_smmu_master(smmu, dev->of_node);
-                if (master)
-                        break;
-        }
-        spin_unlock(&arm_smmu_devices_lock);
-
-        if (!master)
+        smmu = find_smmu_for_device(dev);
+        if (!smmu)
                 return -ENODEV;
 
         group = iommu_group_alloc();
@@ -1596,15 +1559,40 @@ static int arm_smmu_add_device(struct device *dev)
                 return PTR_ERR(group);
         }
 
+        if (dev_is_pci(dev)) {
+                struct arm_smmu_master_cfg *cfg;
+                struct pci_dev *pdev = to_pci_dev(dev);
+
+                cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
+                if (!cfg) {
+                        ret = -ENOMEM;
+                        goto out_put_group;
+                }
+
+                cfg->num_streamids = 1;
+                /*
+                 * Assume Stream ID == Requester ID for now.
+                 * We need a way to describe the ID mappings in FDT.
+                 */
+                pci_for_each_dma_alias(pdev, __arm_smmu_get_pci_sid,
+                                       &cfg->streamids[0]);
+                dev->archdata.iommu = cfg;
+        } else {
+                dev->archdata.iommu = smmu;
+        }
+
         ret = iommu_group_add_device(group, dev);
-        iommu_group_put(group);
-        dev->archdata.iommu = smmu;
 
+out_put_group:
+        iommu_group_put(group);
         return ret;
 }
 
 static void arm_smmu_remove_device(struct device *dev)
 {
+        if (dev_is_pci(dev))
+                kfree(dev->archdata.iommu);
+
         dev->archdata.iommu = NULL;
         iommu_group_remove_device(dev);
 }
@@ -1639,7 +1627,8 @@ static void arm_smmu_device_reset(struct arm_smmu_device *smmu)
         /* Mark all SMRn as invalid and all S2CRn as bypass */
         for (i = 0; i < smmu->num_mapping_groups; ++i) {
                 writel_relaxed(~SMR_VALID, gr0_base + ARM_SMMU_GR0_SMR(i));
-                writel_relaxed(S2CR_TYPE_BYPASS, gr0_base + ARM_SMMU_GR0_S2CR(i));
+                writel_relaxed(S2CR_TYPE_BYPASS,
+                        gr0_base + ARM_SMMU_GR0_S2CR(i));
         }
 
         /* Make sure all context banks are disabled and clear CB_FSR  */
@@ -1779,11 +1768,13 @@ static int arm_smmu_device_cfg_probe(struct arm_smmu_device *smmu)
         smmu->pagesize = (id & ID1_PAGESIZE) ? SZ_64K : SZ_4K;
 
         /* Check for size mismatch of SMMU address space from mapped region */
-        size = 1 << (((id >> ID1_NUMPAGENDXB_SHIFT) & ID1_NUMPAGENDXB_MASK) + 1);
+        size = 1 <<
+                (((id >> ID1_NUMPAGENDXB_SHIFT) & ID1_NUMPAGENDXB_MASK) + 1);
         size *= (smmu->pagesize << 1);
         if (smmu->size != size)
-                dev_warn(smmu->dev, "SMMU address space size (0x%lx) differs "
-                        "from mapped region size (0x%lx)!\n", size, smmu->size);
+                dev_warn(smmu->dev,
+                        "SMMU address space size (0x%lx) differs from mapped region size (0x%lx)!\n",
+                        size, smmu->size);
 
         smmu->num_s2_context_banks = (id >> ID1_NUMS2CB_SHIFT) &
                                       ID1_NUMS2CB_MASK;
@@ -1804,14 +1795,14 @@ static int arm_smmu_device_cfg_probe(struct arm_smmu_device *smmu)
          * allocation (PTRS_PER_PGD).
          */
 #ifdef CONFIG_64BIT
-        smmu->s1_output_size = min((unsigned long)VA_BITS, size);
+        smmu->s1_output_size = min_t(unsigned long, VA_BITS, size);
 #else
         smmu->s1_output_size = min(32UL, size);
 #endif
 
         /* The stage-2 output mask is also applied for bypass */
         size = arm_smmu_id_size_to_bits((id >> ID2_OAS_SHIFT) & ID2_OAS_MASK);
-        smmu->s2_output_size = min((unsigned long)PHYS_MASK_SHIFT, size);
+        smmu->s2_output_size = min_t(unsigned long, PHYS_MASK_SHIFT, size);
 
         if (smmu->version == 1) {
                 smmu->input_size = 32;
@@ -1835,7 +1826,8 @@ static int arm_smmu_device_cfg_probe(struct arm_smmu_device *smmu)
 
         dev_notice(smmu->dev,
                    "\t%lu-bit VA, %lu-bit IPA, %lu-bit PA\n",
-                   smmu->input_size, smmu->s1_output_size, smmu->s2_output_size);
+                   smmu->input_size, smmu->s1_output_size,
+                   smmu->s2_output_size);
         return 0;
 }
 
@@ -1843,7 +1835,6 @@ static int arm_smmu_device_dt_probe(struct platform_device *pdev)
 {
         struct resource *res;
         struct arm_smmu_device *smmu;
-        struct device_node *dev_node;
         struct device *dev = &pdev->dev;
         struct rb_node *node;
         struct of_phandle_args masterspec;
@@ -1890,6 +1881,7 @@ static int arm_smmu_device_dt_probe(struct platform_device *pdev)
 
         for (i = 0; i < num_irqs; ++i) {
                 int irq = platform_get_irq(pdev, i);
+
                 if (irq < 0) {
                         dev_err(dev, "failed to get irq index %d\n", i);
                         return -ENODEV;
@@ -1913,12 +1905,9 @@ static int arm_smmu_device_dt_probe(struct platform_device *pdev)
         }
         dev_notice(dev, "registered %d master devices\n", i);
 
-        if ((dev_node = of_parse_phandle(dev->of_node, "smmu-parent", 0)))
-                smmu->parent_of_node = dev_node;
-
         err = arm_smmu_device_cfg_probe(smmu);
         if (err)
-                goto out_put_parent;
+                goto out_put_masters;
 
         parse_driver_options(smmu);
 
@@ -1928,7 +1917,7 @@ static int arm_smmu_device_dt_probe(struct platform_device *pdev)
                         "found only %d context interrupt(s) but %d required\n",
                         smmu->num_context_irqs, smmu->num_context_banks);
                 err = -ENODEV;
-                goto out_put_parent;
+                goto out_put_masters;
         }
 
         for (i = 0; i < smmu->num_global_irqs; ++i) {
@@ -1956,14 +1945,10 @@ out_free_irqs:
         while (i--)
                 free_irq(smmu->irqs[i], smmu);
 
-out_put_parent:
-        if (smmu->parent_of_node)
-                of_node_put(smmu->parent_of_node);
-
 out_put_masters:
         for (node = rb_first(&smmu->masters); node; node = rb_next(node)) {
-                struct arm_smmu_master *master;
-                master = container_of(node, struct arm_smmu_master, node);
+                struct arm_smmu_master *master
+                        = container_of(node, struct arm_smmu_master, node);
                 of_node_put(master->of_node);
         }
 
@@ -1990,12 +1975,9 @@ static int arm_smmu_device_remove(struct platform_device *pdev)
         if (!smmu)
                 return -ENODEV;
 
-        if (smmu->parent_of_node)
-                of_node_put(smmu->parent_of_node);
-
         for (node = rb_first(&smmu->masters); node; node = rb_next(node)) {
-                struct arm_smmu_master *master;
-                master = container_of(node, struct arm_smmu_master, node);
+                struct arm_smmu_master *master
+                        = container_of(node, struct arm_smmu_master, node);
                 of_node_put(master->of_node);
         }
 
@@ -2006,7 +1988,7 @@ static int arm_smmu_device_remove(struct platform_device *pdev)
                 free_irq(smmu->irqs[i], smmu);
 
         /* Turn the thing off */
-        writel(sCR0_CLIENTPD,ARM_SMMU_GR0_NS(smmu) + ARM_SMMU_GR0_sCR0);
+        writel(sCR0_CLIENTPD, ARM_SMMU_GR0_NS(smmu) + ARM_SMMU_GR0_sCR0);
         return 0;
 }
 
@@ -2048,6 +2030,11 @@ static int __init arm_smmu_init(void)
                 bus_set_iommu(&amba_bustype, &arm_smmu_ops);
 #endif
 
+#ifdef CONFIG_PCI
+        if (!iommu_present(&pci_bus_type))
+                bus_set_iommu(&pci_bus_type, &arm_smmu_ops);
+#endif
+
         return 0;
 }