OpenWrt – Rev 4

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From 0a6c701f92e1aa368c44632fa0985e92703354ed Mon Sep 17 00:00:00 2001
From: Yangbo Lu <yangbo.lu@nxp.com>
Date: Wed, 17 Jan 2018 15:35:48 +0800
Subject: [PATCH 22/30] iommu: support layerscape

This is an integrated patch for layerscape smmu support.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Nipun Gupta <nipun.gupta@nxp.com>
Signed-off-by: Sunil Goutham <sgoutham@cavium.com>
Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
---
 drivers/iommu/amd_iommu.c    |  56 ++++++----
 drivers/iommu/arm-smmu-v3.c  | 111 ++++++++++++++------
 drivers/iommu/arm-smmu.c     | 100 +++++++++++++++---
 drivers/iommu/dma-iommu.c    | 242 ++++++++++++++++++++++++++++++++++++-------
 drivers/iommu/intel-iommu.c  |  92 ++++++++++++----
 drivers/iommu/iommu.c        | 219 ++++++++++++++++++++++++++++++++++++---
 drivers/iommu/mtk_iommu.c    |   2 +
 drivers/iommu/mtk_iommu_v1.c |   2 +
 include/linux/dma-iommu.h    |  11 ++
 include/linux/iommu.h        |  55 +++++++---
 10 files changed, 739 insertions(+), 151 deletions(-)

--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -373,6 +373,8 @@ static struct iommu_group *acpihid_devic
 
        if (!entry->group)
                entry->group = generic_device_group(dev);
+       else
+               iommu_group_ref_get(entry->group);
 
        return entry->group;
 }
@@ -3160,9 +3162,10 @@ static bool amd_iommu_capable(enum iommu
        return false;
 }
 
-static void amd_iommu_get_dm_regions(struct device *dev,
-                                    struct list_head *head)
+static void amd_iommu_get_resv_regions(struct device *dev,
+                                      struct list_head *head)
 {
+       struct iommu_resv_region *region;
        struct unity_map_entry *entry;
        int devid;
 
@@ -3171,41 +3174,56 @@ static void amd_iommu_get_dm_regions(str
                return;
 
        list_for_each_entry(entry, &amd_iommu_unity_map, list) {
-               struct iommu_dm_region *region;
+               size_t length;
+               int prot = 0;
 
                if (devid < entry->devid_start || devid > entry->devid_end)
                        continue;
 
-               region = kzalloc(sizeof(*region), GFP_KERNEL);
+               length = entry->address_end - entry->address_start;
+               if (entry->prot & IOMMU_PROT_IR)
+                       prot |= IOMMU_READ;
+               if (entry->prot & IOMMU_PROT_IW)
+                       prot |= IOMMU_WRITE;
+
+               region = iommu_alloc_resv_region(entry->address_start,
+                                                length, prot,
+                                                IOMMU_RESV_DIRECT);
                if (!region) {
                        pr_err("Out of memory allocating dm-regions for %s\n",
                                dev_name(dev));
                        return;
                }
-
-               region->start = entry->address_start;
-               region->length = entry->address_end - entry->address_start;
-               if (entry->prot & IOMMU_PROT_IR)
-                       region->prot |= IOMMU_READ;
-               if (entry->prot & IOMMU_PROT_IW)
-                       region->prot |= IOMMU_WRITE;
-
                list_add_tail(&region->list, head);
        }
+
+       region = iommu_alloc_resv_region(MSI_RANGE_START,
+                                        MSI_RANGE_END - MSI_RANGE_START + 1,
+                                        0, IOMMU_RESV_MSI);
+       if (!region)
+               return;
+       list_add_tail(&region->list, head);
+
+       region = iommu_alloc_resv_region(HT_RANGE_START,
+                                        HT_RANGE_END - HT_RANGE_START + 1,
+                                        0, IOMMU_RESV_RESERVED);
+       if (!region)
+               return;
+       list_add_tail(&region->list, head);
 }
 
-static void amd_iommu_put_dm_regions(struct device *dev,
+static void amd_iommu_put_resv_regions(struct device *dev,
                                     struct list_head *head)
 {
-       struct iommu_dm_region *entry, *next;
+       struct iommu_resv_region *entry, *next;
 
        list_for_each_entry_safe(entry, next, head, list)
                kfree(entry);
 }
 
-static void amd_iommu_apply_dm_region(struct device *dev,
+static void amd_iommu_apply_resv_region(struct device *dev,
                                      struct iommu_domain *domain,
-                                     struct iommu_dm_region *region)
+                                     struct iommu_resv_region *region)
 {
        struct dma_ops_domain *dma_dom = to_dma_ops_domain(to_pdomain(domain));
        unsigned long start, end;
@@ -3229,9 +3247,9 @@ static const struct iommu_ops amd_iommu_
        .add_device = amd_iommu_add_device,
        .remove_device = amd_iommu_remove_device,
        .device_group = amd_iommu_device_group,
-       .get_dm_regions = amd_iommu_get_dm_regions,
-       .put_dm_regions = amd_iommu_put_dm_regions,
-       .apply_dm_region = amd_iommu_apply_dm_region,
+       .get_resv_regions = amd_iommu_get_resv_regions,
+       .put_resv_regions = amd_iommu_put_resv_regions,
+       .apply_resv_region = amd_iommu_apply_resv_region,
        .pgsize_bitmap  = AMD_IOMMU_PGSIZES,
 };
 
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -410,6 +410,9 @@
 /* High-level queue structures */
 #define ARM_SMMU_POLL_TIMEOUT_US       100
 
+#define MSI_IOVA_BASE                  0x8000000
+#define MSI_IOVA_LENGTH                        0x100000
+
 static bool disable_bypass;
 module_param_named(disable_bypass, disable_bypass, bool, S_IRUGO);
 MODULE_PARM_DESC(disable_bypass,
@@ -552,9 +555,14 @@ struct arm_smmu_s2_cfg {
 };
 
 struct arm_smmu_strtab_ent {
-       bool                            valid;
-
-       bool                            bypass; /* Overrides s1/s2 config */
+       /*
+        * An STE is "assigned" if the master emitting the corresponding SID
+        * is attached to a domain. The behaviour of an unassigned STE is
+        * determined by the disable_bypass parameter, whereas an assigned
+        * STE behaves according to s1_cfg/s2_cfg, which themselves are
+        * configured according to the domain type.
+        */
+       bool                            assigned;
        struct arm_smmu_s1_cfg          *s1_cfg;
        struct arm_smmu_s2_cfg          *s2_cfg;
 };
@@ -627,6 +635,7 @@ enum arm_smmu_domain_stage {
        ARM_SMMU_DOMAIN_S1 = 0,
        ARM_SMMU_DOMAIN_S2,
        ARM_SMMU_DOMAIN_NESTED,
+       ARM_SMMU_DOMAIN_BYPASS,
 };
 
 struct arm_smmu_domain {
@@ -1000,9 +1009,9 @@ static void arm_smmu_write_strtab_ent(st
         * This is hideously complicated, but we only really care about
         * three cases at the moment:
         *
-        * 1. Invalid (all zero) -> bypass  (init)
-        * 2. Bypass -> translation (attach)
-        * 3. Translation -> bypass (detach)
+        * 1. Invalid (all zero) -> bypass/fault (init)
+        * 2. Bypass/fault -> translation/bypass (attach)
+        * 3. Translation/bypass -> bypass/fault (detach)
         *
         * Given that we can't update the STE atomically and the SMMU
         * doesn't read the thing in a defined order, that leaves us
@@ -1041,11 +1050,15 @@ static void arm_smmu_write_strtab_ent(st
        }
 
        /* Nuke the existing STE_0 value, as we're going to rewrite it */
-       val = ste->valid ? STRTAB_STE_0_V : 0;
+       val = STRTAB_STE_0_V;
+
+       /* Bypass/fault */
+       if (!ste->assigned || !(ste->s1_cfg || ste->s2_cfg)) {
+               if (!ste->assigned && disable_bypass)
+                       val |= STRTAB_STE_0_CFG_ABORT;
+               else
+                       val |= STRTAB_STE_0_CFG_BYPASS;
 
-       if (ste->bypass) {
-               val |= disable_bypass ? STRTAB_STE_0_CFG_ABORT
-                                     : STRTAB_STE_0_CFG_BYPASS;
                dst[0] = cpu_to_le64(val);
                dst[1] = cpu_to_le64(STRTAB_STE_1_SHCFG_INCOMING
                         << STRTAB_STE_1_SHCFG_SHIFT);
@@ -1108,10 +1121,7 @@ static void arm_smmu_write_strtab_ent(st
 static void arm_smmu_init_bypass_stes(u64 *strtab, unsigned int nent)
 {
        unsigned int i;
-       struct arm_smmu_strtab_ent ste = {
-               .valid  = true,
-               .bypass = true,
-       };
+       struct arm_smmu_strtab_ent ste = { .assigned = false };
 
        for (i = 0; i < nent; ++i) {
                arm_smmu_write_strtab_ent(NULL, -1, strtab, &ste);
@@ -1364,8 +1374,6 @@ static bool arm_smmu_capable(enum iommu_
        switch (cap) {
        case IOMMU_CAP_CACHE_COHERENCY:
                return true;
-       case IOMMU_CAP_INTR_REMAP:
-               return true; /* MSIs are just memory writes */
        case IOMMU_CAP_NOEXEC:
                return true;
        default:
@@ -1377,7 +1385,9 @@ static struct iommu_domain *arm_smmu_dom
 {
        struct arm_smmu_domain *smmu_domain;
 
-       if (type != IOMMU_DOMAIN_UNMANAGED && type != IOMMU_DOMAIN_DMA)
+       if (type != IOMMU_DOMAIN_UNMANAGED &&
+           type != IOMMU_DOMAIN_DMA &&
+           type != IOMMU_DOMAIN_IDENTITY)
                return NULL;
 
        /*
@@ -1508,6 +1518,11 @@ static int arm_smmu_domain_finalise(stru
        struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
        struct arm_smmu_device *smmu = smmu_domain->smmu;
 
+       if (domain->type == IOMMU_DOMAIN_IDENTITY) {
+               smmu_domain->stage = ARM_SMMU_DOMAIN_BYPASS;
+               return 0;
+       }
+
        /* Restrict the stage to what we can actually support */
        if (!(smmu->features & ARM_SMMU_FEAT_TRANS_S1))
                smmu_domain->stage = ARM_SMMU_DOMAIN_S2;
@@ -1580,7 +1595,7 @@ static __le64 *arm_smmu_get_step_for_sid
        return step;
 }
 
-static int arm_smmu_install_ste_for_dev(struct iommu_fwspec *fwspec)
+static void arm_smmu_install_ste_for_dev(struct iommu_fwspec *fwspec)
 {
        int i, j;
        struct arm_smmu_master_data *master = fwspec->iommu_priv;
@@ -1599,17 +1614,14 @@ static int arm_smmu_install_ste_for_dev(
 
                arm_smmu_write_strtab_ent(smmu, sid, step, &master->ste);
        }
-
-       return 0;
 }
 
 static void arm_smmu_detach_dev(struct device *dev)
 {
        struct arm_smmu_master_data *master = dev->iommu_fwspec->iommu_priv;
 
-       master->ste.bypass = true;
-       if (arm_smmu_install_ste_for_dev(dev->iommu_fwspec) < 0)
-               dev_warn(dev, "failed to install bypass STE\n");
+       master->ste.assigned = false;
+       arm_smmu_install_ste_for_dev(dev->iommu_fwspec);
 }
 
 static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
@@ -1628,7 +1640,7 @@ static int arm_smmu_attach_dev(struct io
        ste = &master->ste;
 
        /* Already attached to a different domain? */
-       if (!ste->bypass)
+       if (ste->assigned)
                arm_smmu_detach_dev(dev);
 
        mutex_lock(&smmu_domain->init_mutex);
@@ -1649,10 +1661,12 @@ static int arm_smmu_attach_dev(struct io
                goto out_unlock;
        }
 
-       ste->bypass = false;
-       ste->valid = true;
+       ste->assigned = true;
 
-       if (smmu_domain->stage == ARM_SMMU_DOMAIN_S1) {
+       if (smmu_domain->stage == ARM_SMMU_DOMAIN_BYPASS) {
+               ste->s1_cfg = NULL;
+               ste->s2_cfg = NULL;
+       } else if (smmu_domain->stage == ARM_SMMU_DOMAIN_S1) {
                ste->s1_cfg = &smmu_domain->s1_cfg;
                ste->s2_cfg = NULL;
                arm_smmu_write_ctx_desc(smmu, ste->s1_cfg);
@@ -1661,10 +1675,7 @@ static int arm_smmu_attach_dev(struct io
                ste->s2_cfg = &smmu_domain->s2_cfg;
        }
 
-       ret = arm_smmu_install_ste_for_dev(dev->iommu_fwspec);
-       if (ret < 0)
-               ste->valid = false;
-
+       arm_smmu_install_ste_for_dev(dev->iommu_fwspec);
 out_unlock:
        mutex_unlock(&smmu_domain->init_mutex);
        return ret;
@@ -1712,6 +1723,9 @@ arm_smmu_iova_to_phys(struct iommu_domai
        struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
        struct io_pgtable_ops *ops = smmu_domain->pgtbl_ops;
 
+       if (domain->type == IOMMU_DOMAIN_IDENTITY)
+               return iova;
+
        if (!ops)
                return 0;
 
@@ -1810,7 +1824,7 @@ static void arm_smmu_remove_device(struc
                return;
 
        master = fwspec->iommu_priv;
-       if (master && master->ste.valid)
+       if (master && master->ste.assigned)
                arm_smmu_detach_dev(dev);
        iommu_group_remove_device(dev);
        kfree(master);
@@ -1839,6 +1853,9 @@ static int arm_smmu_domain_get_attr(stru
 {
        struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
 
+       if (domain->type != IOMMU_DOMAIN_UNMANAGED)
+               return -EINVAL;
+
        switch (attr) {
        case DOMAIN_ATTR_NESTING:
                *(int *)data = (smmu_domain->stage == ARM_SMMU_DOMAIN_NESTED);
@@ -1854,6 +1871,9 @@ static int arm_smmu_domain_set_attr(stru
        int ret = 0;
        struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
 
+       if (domain->type != IOMMU_DOMAIN_UNMANAGED)
+               return -EINVAL;
+
        mutex_lock(&smmu_domain->init_mutex);
 
        switch (attr) {
@@ -1883,6 +1903,31 @@ static int arm_smmu_of_xlate(struct devi
        return iommu_fwspec_add_ids(dev, args->args, 1);
 }
 
+static void arm_smmu_get_resv_regions(struct device *dev,
+                                     struct list_head *head)
+{
+       struct iommu_resv_region *region;
+       int prot = IOMMU_WRITE | IOMMU_NOEXEC | IOMMU_MMIO;
+
+       region = iommu_alloc_resv_region(MSI_IOVA_BASE, MSI_IOVA_LENGTH,
+                                        prot, IOMMU_RESV_SW_MSI);
+       if (!region)
+               return;
+
+       list_add_tail(&region->list, head);
+
+       iommu_dma_get_resv_regions(dev, head);
+}
+
+static void arm_smmu_put_resv_regions(struct device *dev,
+                                     struct list_head *head)
+{
+       struct iommu_resv_region *entry, *next;
+
+       list_for_each_entry_safe(entry, next, head, list)
+               kfree(entry);
+}
+
 static struct iommu_ops arm_smmu_ops = {
        .capable                = arm_smmu_capable,
        .domain_alloc           = arm_smmu_domain_alloc,
@@ -1898,6 +1943,8 @@ static struct iommu_ops arm_smmu_ops = {
        .domain_get_attr        = arm_smmu_domain_get_attr,
        .domain_set_attr        = arm_smmu_domain_set_attr,
        .of_xlate               = arm_smmu_of_xlate,
+       .get_resv_regions       = arm_smmu_get_resv_regions,
+       .put_resv_regions       = arm_smmu_put_resv_regions,
        .pgsize_bitmap          = -1UL, /* Restricted during device attach */
 };
 
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -49,6 +49,7 @@
 #include <linux/spinlock.h>
 
 #include <linux/amba/bus.h>
+#include "../staging/fsl-mc/include/mc-bus.h"
 
 #include "io-pgtable.h"
 
@@ -247,6 +248,7 @@ enum arm_smmu_s2cr_privcfg {
 #define ARM_MMU500_ACTLR_CPRE          (1 << 1)
 
 #define ARM_MMU500_ACR_CACHE_LOCK      (1 << 26)
+#define ARM_MMU500_ACR_SMTNMB_TLBEN    (1 << 8)
 
 #define CB_PAR_F                       (1 << 0)
 
@@ -278,6 +280,9 @@ enum arm_smmu_s2cr_privcfg {
 
 #define FSYNR0_WNR                     (1 << 4)
 
+#define MSI_IOVA_BASE                  0x8000000
+#define MSI_IOVA_LENGTH                        0x100000
+
 static int force_stage;
 module_param(force_stage, int, S_IRUGO);
 MODULE_PARM_DESC(force_stage,
@@ -401,6 +406,7 @@ enum arm_smmu_domain_stage {
        ARM_SMMU_DOMAIN_S1 = 0,
        ARM_SMMU_DOMAIN_S2,
        ARM_SMMU_DOMAIN_NESTED,
+       ARM_SMMU_DOMAIN_BYPASS,
 };
 
 struct arm_smmu_domain {
@@ -821,6 +827,12 @@ static int arm_smmu_init_domain_context(
        if (smmu_domain->smmu)
                goto out_unlock;
 
+       if (domain->type == IOMMU_DOMAIN_IDENTITY) {
+               smmu_domain->stage = ARM_SMMU_DOMAIN_BYPASS;
+               smmu_domain->smmu = smmu;
+               goto out_unlock;
+       }
+
        /*
         * Mapping the requested stage onto what we support is surprisingly
         * complicated, mainly because the spec allows S1+S2 SMMUs without
@@ -981,7 +993,7 @@ static void arm_smmu_destroy_domain_cont
        void __iomem *cb_base;
        int irq;
 
-       if (!smmu)
+       if (!smmu || domain->type == IOMMU_DOMAIN_IDENTITY)
                return;
 
        /*
@@ -1004,7 +1016,9 @@ static struct iommu_domain *arm_smmu_dom
 {
        struct arm_smmu_domain *smmu_domain;
 
-       if (type != IOMMU_DOMAIN_UNMANAGED && type != IOMMU_DOMAIN_DMA)
+       if (type != IOMMU_DOMAIN_UNMANAGED &&
+           type != IOMMU_DOMAIN_DMA &&
+           type != IOMMU_DOMAIN_IDENTITY)
                return NULL;
        /*
         * Allocate the domain and initialise some of its data structures.
@@ -1202,10 +1216,15 @@ static int arm_smmu_domain_add_master(st
 {
        struct arm_smmu_device *smmu = smmu_domain->smmu;
        struct arm_smmu_s2cr *s2cr = smmu->s2crs;
-       enum arm_smmu_s2cr_type type = S2CR_TYPE_TRANS;
        u8 cbndx = smmu_domain->cfg.cbndx;
+       enum arm_smmu_s2cr_type type;
        int i, idx;
 
+       if (smmu_domain->stage == ARM_SMMU_DOMAIN_BYPASS)
+               type = S2CR_TYPE_BYPASS;
+       else
+               type = S2CR_TYPE_TRANS;
+
        for_each_cfg_sme(fwspec, i, idx) {
                if (type == s2cr[idx].type && cbndx == s2cr[idx].cbndx)
                        continue;
@@ -1343,6 +1362,9 @@ static phys_addr_t arm_smmu_iova_to_phys
        struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
        struct io_pgtable_ops *ops= smmu_domain->pgtbl_ops;
 
+       if (domain->type == IOMMU_DOMAIN_IDENTITY)
+               return iova;
+
        if (!ops)
                return 0;
 
@@ -1368,8 +1390,6 @@ static bool arm_smmu_capable(enum iommu_
                 * requests.
                 */
                return true;
-       case IOMMU_CAP_INTR_REMAP:
-               return true; /* MSIs are just memory writes */
        case IOMMU_CAP_NOEXEC:
                return true;
        default:
@@ -1478,10 +1498,12 @@ static struct iommu_group *arm_smmu_devi
        }
 
        if (group)
-               return group;
+               return iommu_group_ref_get(group);
 
        if (dev_is_pci(dev))
                group = pci_device_group(dev);
+       else if (dev_is_fsl_mc(dev))
+               group = fsl_mc_device_group(dev);
        else
                group = generic_device_group(dev);
 
@@ -1493,6 +1515,9 @@ static int arm_smmu_domain_get_attr(stru
 {
        struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
 
+       if (domain->type != IOMMU_DOMAIN_UNMANAGED)
+               return -EINVAL;
+
        switch (attr) {
        case DOMAIN_ATTR_NESTING:
                *(int *)data = (smmu_domain->stage == ARM_SMMU_DOMAIN_NESTED);
@@ -1508,6 +1533,9 @@ static int arm_smmu_domain_set_attr(stru
        int ret = 0;
        struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
 
+       if (domain->type != IOMMU_DOMAIN_UNMANAGED)
+               return -EINVAL;
+
        mutex_lock(&smmu_domain->init_mutex);
 
        switch (attr) {
@@ -1534,17 +1562,44 @@ out_unlock:
 
 static int arm_smmu_of_xlate(struct device *dev, struct of_phandle_args *args)
 {
-       u32 fwid = 0;
+       u32 mask, fwid = 0;
 
        if (args->args_count > 0)
                fwid |= (u16)args->args[0];
 
        if (args->args_count > 1)
                fwid |= (u16)args->args[1] << SMR_MASK_SHIFT;
+       else if (!of_property_read_u32(args->np, "stream-match-mask", &mask))
+               fwid |= (u16)mask << SMR_MASK_SHIFT;
 
        return iommu_fwspec_add_ids(dev, &fwid, 1);
 }
 
+static void arm_smmu_get_resv_regions(struct device *dev,
+                                     struct list_head *head)
+{
+       struct iommu_resv_region *region;
+       int prot = IOMMU_WRITE | IOMMU_NOEXEC | IOMMU_MMIO;
+
+       region = iommu_alloc_resv_region(MSI_IOVA_BASE, MSI_IOVA_LENGTH,
+                                        prot, IOMMU_RESV_SW_MSI);
+       if (!region)
+               return;
+
+       list_add_tail(&region->list, head);
+
+       iommu_dma_get_resv_regions(dev, head);
+}
+
+static void arm_smmu_put_resv_regions(struct device *dev,
+                                     struct list_head *head)
+{
+       struct iommu_resv_region *entry, *next;
+
+       list_for_each_entry_safe(entry, next, head, list)
+               kfree(entry);
+}
+
 static struct iommu_ops arm_smmu_ops = {
        .capable                = arm_smmu_capable,
        .domain_alloc           = arm_smmu_domain_alloc,
@@ -1560,6 +1615,8 @@ static struct iommu_ops arm_smmu_ops = {
        .domain_get_attr        = arm_smmu_domain_get_attr,
        .domain_set_attr        = arm_smmu_domain_set_attr,
        .of_xlate               = arm_smmu_of_xlate,
+       .get_resv_regions       = arm_smmu_get_resv_regions,
+       .put_resv_regions       = arm_smmu_put_resv_regions,
        .pgsize_bitmap          = -1UL, /* Restricted during device attach */
 };
 
@@ -1581,16 +1638,22 @@ static void arm_smmu_device_reset(struct
        for (i = 0; i < smmu->num_mapping_groups; ++i)
                arm_smmu_write_sme(smmu, i);
 
-       /*
-        * Before clearing ARM_MMU500_ACTLR_CPRE, need to
-        * clear CACHE_LOCK bit of ACR first. And, CACHE_LOCK
-        * bit is only present in MMU-500r2 onwards.
-        */
-       reg = readl_relaxed(gr0_base + ARM_SMMU_GR0_ID7);
-       major = (reg >> ID7_MAJOR_SHIFT) & ID7_MAJOR_MASK;
-       if ((smmu->model == ARM_MMU500) && (major >= 2)) {
+       if (smmu->model == ARM_MMU500) {
+               /*
+                * Before clearing ARM_MMU500_ACTLR_CPRE, need to
+                * clear CACHE_LOCK bit of ACR first. And, CACHE_LOCK
+                * bit is only present in MMU-500r2 onwards.
+                */
+               reg = readl_relaxed(gr0_base + ARM_SMMU_GR0_ID7);
+               major = (reg >> ID7_MAJOR_SHIFT) & ID7_MAJOR_MASK;
                reg = readl_relaxed(gr0_base + ARM_SMMU_GR0_sACR);
-               reg &= ~ARM_MMU500_ACR_CACHE_LOCK;
+               if (major >= 2)
+                       reg &= ~ARM_MMU500_ACR_CACHE_LOCK;
+               /*
+                * Allow unmatched Stream IDs to allocate bypass
+                * TLB entries for reduced latency.
+                */
+               reg |= ARM_MMU500_ACR_SMTNMB_TLBEN;
                writel_relaxed(reg, gr0_base + ARM_SMMU_GR0_sACR);
        }
 
@@ -2024,6 +2087,11 @@ static int arm_smmu_device_dt_probe(stru
                bus_set_iommu(&pci_bus_type, &arm_smmu_ops);
        }
 #endif
+#ifdef CONFIG_FSL_MC_BUS
+       if (!iommu_present(&fsl_mc_bus_type))
+               bus_set_iommu(&fsl_mc_bus_type, &arm_smmu_ops);
+#endif
+
        return 0;
 }
 
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -37,15 +37,50 @@ struct iommu_dma_msi_page {
        phys_addr_t             phys;
 };
 
+enum iommu_dma_cookie_type {
+       IOMMU_DMA_IOVA_COOKIE,
+       IOMMU_DMA_MSI_COOKIE,
+};
+
 struct iommu_dma_cookie {
-       struct iova_domain      iovad;
-       struct list_head        msi_page_list;
-       spinlock_t              msi_lock;
+       enum iommu_dma_cookie_type      type;
+       union {
+               /* Full allocator for IOMMU_DMA_IOVA_COOKIE */
+               struct iova_domain      iovad;
+               /* Trivial linear page allocator for IOMMU_DMA_MSI_COOKIE */
+               dma_addr_t              msi_iova;
+       };
+       struct list_head                msi_page_list;
+       spinlock_t                      msi_lock;
 };
 
+static inline size_t cookie_msi_granule(struct iommu_dma_cookie *cookie)
+{
+       if (cookie->type == IOMMU_DMA_IOVA_COOKIE)
+               return cookie->iovad.granule;
+       return PAGE_SIZE;
+}
+
 static inline struct iova_domain *cookie_iovad(struct iommu_domain *domain)
 {
-       return &((struct iommu_dma_cookie *)domain->iova_cookie)->iovad;
+       struct iommu_dma_cookie *cookie = domain->iova_cookie;
+
+       if (cookie->type == IOMMU_DMA_IOVA_COOKIE)
+               return &cookie->iovad;
+       return NULL;
+}
+
+static struct iommu_dma_cookie *cookie_alloc(enum iommu_dma_cookie_type type)
+{
+       struct iommu_dma_cookie *cookie;
+
+       cookie = kzalloc(sizeof(*cookie), GFP_KERNEL);
+       if (cookie) {
+               spin_lock_init(&cookie->msi_lock);
+               INIT_LIST_HEAD(&cookie->msi_page_list);
+               cookie->type = type;
+       }
+       return cookie;
 }
 
 int iommu_dma_init(void)
@@ -62,25 +97,53 @@ int iommu_dma_init(void)
  */
 int iommu_get_dma_cookie(struct iommu_domain *domain)
 {
+       if (domain->iova_cookie)
+               return -EEXIST;
+
+       domain->iova_cookie = cookie_alloc(IOMMU_DMA_IOVA_COOKIE);
+       if (!domain->iova_cookie)
+               return -ENOMEM;
+
+       return 0;
+}
+EXPORT_SYMBOL(iommu_get_dma_cookie);
+
+/**
+ * iommu_get_msi_cookie - Acquire just MSI remapping resources
+ * @domain: IOMMU domain to prepare
+ * @base: Start address of IOVA region for MSI mappings
+ *
+ * Users who manage their own IOVA allocation and do not want DMA API support,
+ * but would still like to take advantage of automatic MSI remapping, can use
+ * this to initialise their own domain appropriately. Users should reserve a
+ * contiguous IOVA region, starting at @base, large enough to accommodate the
+ * number of PAGE_SIZE mappings necessary to cover every MSI doorbell address
+ * used by the devices attached to @domain.
+ */
+int iommu_get_msi_cookie(struct iommu_domain *domain, dma_addr_t base)
+{
        struct iommu_dma_cookie *cookie;
 
+       if (domain->type != IOMMU_DOMAIN_UNMANAGED)
+               return -EINVAL;
+
        if (domain->iova_cookie)
                return -EEXIST;
 
-       cookie = kzalloc(sizeof(*cookie), GFP_KERNEL);
+       cookie = cookie_alloc(IOMMU_DMA_MSI_COOKIE);
        if (!cookie)
                return -ENOMEM;
 
-       spin_lock_init(&cookie->msi_lock);
-       INIT_LIST_HEAD(&cookie->msi_page_list);
+       cookie->msi_iova = base;
        domain->iova_cookie = cookie;
        return 0;
 }
-EXPORT_SYMBOL(iommu_get_dma_cookie);
+EXPORT_SYMBOL(iommu_get_msi_cookie);
 
 /**
  * iommu_put_dma_cookie - Release a domain's DMA mapping resources
- * @domain: IOMMU domain previously prepared by iommu_get_dma_cookie()
+ * @domain: IOMMU domain previously prepared by iommu_get_dma_cookie() or
+ *          iommu_get_msi_cookie()
  *
  * IOMMU drivers should normally call this from their domain_free callback.
  */
@@ -92,7 +155,7 @@ void iommu_put_dma_cookie(struct iommu_d
        if (!cookie)
                return;
 
-       if (cookie->iovad.granule)
+       if (cookie->type == IOMMU_DMA_IOVA_COOKIE && cookie->iovad.granule)
                put_iova_domain(&cookie->iovad);
 
        list_for_each_entry_safe(msi, tmp, &cookie->msi_page_list, list) {
@@ -104,21 +167,99 @@ void iommu_put_dma_cookie(struct iommu_d
 }
 EXPORT_SYMBOL(iommu_put_dma_cookie);
 
-static void iova_reserve_pci_windows(struct pci_dev *dev,
-               struct iova_domain *iovad)
+/**
+ * iommu_dma_get_resv_regions - Reserved region driver helper
+ * @dev: Device from iommu_get_resv_regions()
+ * @list: Reserved region list from iommu_get_resv_regions()
+ *
+ * IOMMU drivers can use this to implement their .get_resv_regions callback
+ * for general non-IOMMU-specific reservations. Currently, this covers host
+ * bridge windows for PCI devices.
+ */
+void iommu_dma_get_resv_regions(struct device *dev, struct list_head *list)
 {
-       struct pci_host_bridge *bridge = pci_find_host_bridge(dev->bus);
+       struct pci_host_bridge *bridge;
        struct resource_entry *window;
-       unsigned long lo, hi;
 
+       if (!dev_is_pci(dev))
+               return;
+
+       bridge = pci_find_host_bridge(to_pci_dev(dev)->bus);
        resource_list_for_each_entry(window, &bridge->windows) {
+               struct iommu_resv_region *region;
+               phys_addr_t start;
+               size_t length;
+
                if (resource_type(window->res) != IORESOURCE_MEM)
                        continue;
 
-               lo = iova_pfn(iovad, window->res->start - window->offset);
-               hi = iova_pfn(iovad, window->res->end - window->offset);
+               start = window->res->start - window->offset;
+               length = window->res->end - window->res->start + 1;
+               region = iommu_alloc_resv_region(start, length, 0,
+                               IOMMU_RESV_RESERVED);
+               if (!region)
+                       return;
+
+               list_add_tail(&region->list, list);
+       }
+}
+EXPORT_SYMBOL(iommu_dma_get_resv_regions);
+
+static int cookie_init_hw_msi_region(struct iommu_dma_cookie *cookie,
+               phys_addr_t start, phys_addr_t end)
+{
+       struct iova_domain *iovad = &cookie->iovad;
+       struct iommu_dma_msi_page *msi_page;
+       int i, num_pages;
+
+       start -= iova_offset(iovad, start);
+       num_pages = iova_align(iovad, end - start) >> iova_shift(iovad);
+
+       msi_page = kcalloc(num_pages, sizeof(*msi_page), GFP_KERNEL);
+       if (!msi_page)
+               return -ENOMEM;
+
+       for (i = 0; i < num_pages; i++) {
+               msi_page[i].phys = start;
+               msi_page[i].iova = start;
+               INIT_LIST_HEAD(&msi_page[i].list);
+               list_add(&msi_page[i].list, &cookie->msi_page_list);
+               start += iovad->granule;
+       }
+
+       return 0;
+}
+
+static int iova_reserve_iommu_regions(struct device *dev,
+               struct iommu_domain *domain)
+{
+       struct iommu_dma_cookie *cookie = domain->iova_cookie;
+       struct iova_domain *iovad = &cookie->iovad;
+       struct iommu_resv_region *region;
+       LIST_HEAD(resv_regions);
+       int ret = 0;
+
+       iommu_get_resv_regions(dev, &resv_regions);
+       list_for_each_entry(region, &resv_regions, list) {
+               unsigned long lo, hi;
+
+               /* We ARE the software that manages these! */
+               if (region->type == IOMMU_RESV_SW_MSI)
+                       continue;
+
+               lo = iova_pfn(iovad, region->start);
+               hi = iova_pfn(iovad, region->start + region->length - 1);
                reserve_iova(iovad, lo, hi);
+
+               if (region->type == IOMMU_RESV_MSI)
+                       ret = cookie_init_hw_msi_region(cookie, region->start,
+                                       region->start + region->length);
+               if (ret)
+                       break;
        }
+       iommu_put_resv_regions(dev, &resv_regions);
+
+       return ret;
 }
 
 /**
@@ -136,11 +277,12 @@ static void iova_reserve_pci_windows(str
 int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,
                u64 size, struct device *dev)
 {
-       struct iova_domain *iovad = cookie_iovad(domain);
+       struct iommu_dma_cookie *cookie = domain->iova_cookie;
+       struct iova_domain *iovad = &cookie->iovad;
        unsigned long order, base_pfn, end_pfn;
 
-       if (!iovad)
-               return -ENODEV;
+       if (!cookie || cookie->type != IOMMU_DMA_IOVA_COOKIE)
+               return -EINVAL;
 
        /* Use the smallest supported page size for IOVA granularity */
        order = __ffs(domain->pgsize_bitmap);
@@ -160,22 +302,37 @@ int iommu_dma_init_domain(struct iommu_d
                end_pfn = min_t(unsigned long, end_pfn,
                                domain->geometry.aperture_end >> order);
        }
+       /*
+        * PCI devices may have larger DMA masks, but still prefer allocating
+        * within a 32-bit mask to avoid DAC addressing. Such limitations don't
+        * apply to the typical platform device, so for those we may as well
+        * leave the cache limit at the top of their range to save an rb_last()
+        * traversal on every allocation.
+        */
+       if (dev && dev_is_pci(dev))
+               end_pfn &= DMA_BIT_MASK(32) >> order;
 
-       /* All we can safely do with an existing domain is enlarge it */
+       /* start_pfn is always nonzero for an already-initialised domain */
        if (iovad->start_pfn) {
                if (1UL << order != iovad->granule ||
-                   base_pfn != iovad->start_pfn ||
-                   end_pfn < iovad->dma_32bit_pfn) {
+                   base_pfn != iovad->start_pfn) {
                        pr_warn("Incompatible range for DMA domain\n");
                        return -EFAULT;
                }
-               iovad->dma_32bit_pfn = end_pfn;
-       } else {
-               init_iova_domain(iovad, 1UL << order, base_pfn, end_pfn);
-               if (dev && dev_is_pci(dev))
-                       iova_reserve_pci_windows(to_pci_dev(dev), iovad);
+               /*
+                * If we have devices with different DMA masks, move the free
+                * area cache limit down for the benefit of the smaller one.
+                */
+               iovad->dma_32bit_pfn = min(end_pfn, iovad->dma_32bit_pfn);
+
+               return 0;
        }
-       return 0;
+
+       init_iova_domain(iovad, 1UL << order, base_pfn, end_pfn);
+       if (!dev)
+               return 0;
+
+       return iova_reserve_iommu_regions(dev, domain);
 }
 EXPORT_SYMBOL(iommu_dma_init_domain);
 
@@ -643,11 +800,12 @@ static struct iommu_dma_msi_page *iommu_
 {
        struct iommu_dma_cookie *cookie = domain->iova_cookie;
        struct iommu_dma_msi_page *msi_page;
-       struct iova_domain *iovad = &cookie->iovad;
+       struct iova_domain *iovad = cookie_iovad(domain);
        struct iova *iova;
        int prot = IOMMU_WRITE | IOMMU_NOEXEC | IOMMU_MMIO;
+       size_t size = cookie_msi_granule(cookie);
 
-       msi_addr &= ~(phys_addr_t)iova_mask(iovad);
+       msi_addr &= ~(phys_addr_t)(size - 1);
        list_for_each_entry(msi_page, &cookie->msi_page_list, list)
                if (msi_page->phys == msi_addr)
                        return msi_page;
@@ -656,13 +814,18 @@ static struct iommu_dma_msi_page *iommu_
        if (!msi_page)
                return NULL;
 
-       iova = __alloc_iova(domain, iovad->granule, dma_get_mask(dev));
-       if (!iova)
-               goto out_free_page;
-
        msi_page->phys = msi_addr;
-       msi_page->iova = iova_dma_addr(iovad, iova);
-       if (iommu_map(domain, msi_page->iova, msi_addr, iovad->granule, prot))
+       if (iovad) {
+               iova = __alloc_iova(domain, size, dma_get_mask(dev));
+               if (!iova)
+                       goto out_free_page;
+               msi_page->iova = iova_dma_addr(iovad, iova);
+       } else {
+               msi_page->iova = cookie->msi_iova;
+               cookie->msi_iova += size;
+       }
+
+       if (iommu_map(domain, msi_page->iova, msi_addr, size, prot))
                goto out_free_iova;
 
        INIT_LIST_HEAD(&msi_page->list);
@@ -670,7 +833,10 @@ static struct iommu_dma_msi_page *iommu_
        return msi_page;
 
 out_free_iova:
-       __free_iova(iovad, iova);
+       if (iovad)
+               __free_iova(iovad, iova);
+       else
+               cookie->msi_iova -= size;
 out_free_page:
        kfree(msi_page);
        return NULL;
@@ -711,7 +877,7 @@ void iommu_dma_map_msi_msg(int irq, stru
                msg->data = ~0U;
        } else {
                msg->address_hi = upper_32_bits(msi_page->iova);
-               msg->address_lo &= iova_mask(&cookie->iovad);
+               msg->address_lo &= cookie_msi_granule(cookie) - 1;
                msg->address_lo += lower_32_bits(msi_page->iova);
        }
 }
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -440,6 +440,7 @@ struct dmar_rmrr_unit {
        u64     end_address;            /* reserved end address */
        struct dmar_dev_scope *devices; /* target devices */
        int     devices_cnt;            /* target device count */
+       struct iommu_resv_region *resv; /* reserved region handle */
 };
 
 struct dmar_atsr_unit {
@@ -4251,27 +4252,40 @@ static inline void init_iommu_pm_ops(voi
 int __init dmar_parse_one_rmrr(struct acpi_dmar_header *header, void *arg)
 {
        struct acpi_dmar_reserved_memory *rmrr;
+       int prot = DMA_PTE_READ|DMA_PTE_WRITE;
        struct dmar_rmrr_unit *rmrru;
+       size_t length;
 
        rmrru = kzalloc(sizeof(*rmrru), GFP_KERNEL);
        if (!rmrru)
-               return -ENOMEM;
+               goto out;
 
        rmrru->hdr = header;
        rmrr = (struct acpi_dmar_reserved_memory *)header;
        rmrru->base_address = rmrr->base_address;
        rmrru->end_address = rmrr->end_address;
+
+       length = rmrr->end_address - rmrr->base_address + 1;
+       rmrru->resv = iommu_alloc_resv_region(rmrr->base_address, length, prot,
+                                             IOMMU_RESV_DIRECT);
+       if (!rmrru->resv)
+               goto free_rmrru;
+
        rmrru->devices = dmar_alloc_dev_scope((void *)(rmrr + 1),
                                ((void *)rmrr) + rmrr->header.length,
                                &rmrru->devices_cnt);
-       if (rmrru->devices_cnt && rmrru->devices == NULL) {
-               kfree(rmrru);
-               return -ENOMEM;
-       }
+       if (rmrru->devices_cnt && rmrru->devices == NULL)
+               goto free_all;
 
        list_add(&rmrru->list, &dmar_rmrr_units);
 
        return 0;
+free_all:
+       kfree(rmrru->resv);
+free_rmrru:
+       kfree(rmrru);
+out:
+       return -ENOMEM;
 }
 
 static struct dmar_atsr_unit *dmar_find_atsr(struct acpi_dmar_atsr *atsr)
@@ -4485,6 +4499,7 @@ static void intel_iommu_free_dmars(void)
        list_for_each_entry_safe(rmrru, rmrr_n, &dmar_rmrr_units, list) {
                list_del(&rmrru->list);
                dmar_free_dev_scope(&rmrru->devices, &rmrru->devices_cnt);
+               kfree(rmrru->resv);
                kfree(rmrru);
        }
 
@@ -5220,6 +5235,45 @@ static void intel_iommu_remove_device(st
        iommu_device_unlink(iommu->iommu_dev, dev);
 }
 
+static void intel_iommu_get_resv_regions(struct device *device,
+                                        struct list_head *head)
+{
+       struct iommu_resv_region *reg;
+       struct dmar_rmrr_unit *rmrr;
+       struct device *i_dev;
+       int i;
+
+       rcu_read_lock();
+       for_each_rmrr_units(rmrr) {
+               for_each_active_dev_scope(rmrr->devices, rmrr->devices_cnt,
+                                         i, i_dev) {
+                       if (i_dev != device)
+                               continue;
+
+                       list_add_tail(&rmrr->resv->list, head);
+               }
+       }
+       rcu_read_unlock();
+
+       reg = iommu_alloc_resv_region(IOAPIC_RANGE_START,
+                                     IOAPIC_RANGE_END - IOAPIC_RANGE_START + 1,
+                                     0, IOMMU_RESV_MSI);
+       if (!reg)
+               return;
+       list_add_tail(&reg->list, head);
+}
+
+static void intel_iommu_put_resv_regions(struct device *dev,
+                                        struct list_head *head)
+{
+       struct iommu_resv_region *entry, *next;
+
+       list_for_each_entry_safe(entry, next, head, list) {
+               if (entry->type == IOMMU_RESV_RESERVED)
+                       kfree(entry);
+       }
+}
+
 #ifdef CONFIG_INTEL_IOMMU_SVM
 #define MAX_NR_PASID_BITS (20)
 static inline unsigned long intel_iommu_get_pts(struct intel_iommu *iommu)
@@ -5350,19 +5404,21 @@ struct intel_iommu *intel_svm_device_to_
 #endif /* CONFIG_INTEL_IOMMU_SVM */
 
 static const struct iommu_ops intel_iommu_ops = {
-       .capable        = intel_iommu_capable,
-       .domain_alloc   = intel_iommu_domain_alloc,
-       .domain_free    = intel_iommu_domain_free,
-       .attach_dev     = intel_iommu_attach_device,
-       .detach_dev     = intel_iommu_detach_device,
-       .map            = intel_iommu_map,
-       .unmap          = intel_iommu_unmap,
-       .map_sg         = default_iommu_map_sg,
-       .iova_to_phys   = intel_iommu_iova_to_phys,
-       .add_device     = intel_iommu_add_device,
-       .remove_device  = intel_iommu_remove_device,
-       .device_group   = pci_device_group,
-       .pgsize_bitmap  = INTEL_IOMMU_PGSIZES,
+       .capable                = intel_iommu_capable,
+       .domain_alloc           = intel_iommu_domain_alloc,
+       .domain_free            = intel_iommu_domain_free,
+       .attach_dev             = intel_iommu_attach_device,
+       .detach_dev             = intel_iommu_detach_device,
+       .map                    = intel_iommu_map,
+       .unmap                  = intel_iommu_unmap,
+       .map_sg                 = default_iommu_map_sg,
+       .iova_to_phys           = intel_iommu_iova_to_phys,
+       .add_device             = intel_iommu_add_device,
+       .remove_device          = intel_iommu_remove_device,
+       .get_resv_regions       = intel_iommu_get_resv_regions,
+       .put_resv_regions       = intel_iommu_put_resv_regions,
+       .device_group           = pci_device_group,
+       .pgsize_bitmap          = INTEL_IOMMU_PGSIZES,
 };
 
 static void quirk_iommu_g4x_gfx(struct pci_dev *dev)
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -36,6 +36,7 @@
 
 static struct kset *iommu_group_kset;
 static DEFINE_IDA(iommu_group_ida);
+static unsigned int iommu_def_domain_type = IOMMU_DOMAIN_DMA;
 
 struct iommu_callback_data {
        const struct iommu_ops *ops;
@@ -68,6 +69,13 @@ struct iommu_group_attribute {
                         const char *buf, size_t count);
 };
 
+static const char * const iommu_group_resv_type_string[] = {
+       [IOMMU_RESV_DIRECT]     = "direct",
+       [IOMMU_RESV_RESERVED]   = "reserved",
+       [IOMMU_RESV_MSI]        = "msi",
+       [IOMMU_RESV_SW_MSI]     = "msi",
+};
+
 #define IOMMU_GROUP_ATTR(_name, _mode, _show, _store)          \
 struct iommu_group_attribute iommu_group_attr_##_name =                \
        __ATTR(_name, _mode, _show, _store)
@@ -86,6 +94,18 @@ static int __iommu_attach_group(struct i
 static void __iommu_detach_group(struct iommu_domain *domain,
                                 struct iommu_group *group);
 
+static int __init iommu_set_def_domain_type(char *str)
+{
+       bool pt;
+
+       if (!str || strtobool(str, &pt))
+               return -EINVAL;
+
+       iommu_def_domain_type = pt ? IOMMU_DOMAIN_IDENTITY : IOMMU_DOMAIN_DMA;
+       return 0;
+}
+early_param("iommu.passthrough", iommu_set_def_domain_type);
+
 static ssize_t iommu_group_attr_show(struct kobject *kobj,
                                     struct attribute *__attr, char *buf)
 {
@@ -133,8 +153,131 @@ static ssize_t iommu_group_show_name(str
        return sprintf(buf, "%s\n", group->name);
 }
 
+/**
+ * iommu_insert_resv_region - Insert a new region in the
+ * list of reserved regions.
+ * @new: new region to insert
+ * @regions: list of regions
+ *
+ * The new element is sorted by address with respect to the other
+ * regions of the same type. In case it overlaps with another
+ * region of the same type, regions are merged. In case it
+ * overlaps with another region of different type, regions are
+ * not merged.
+ */
+static int iommu_insert_resv_region(struct iommu_resv_region *new,
+                                   struct list_head *regions)
+{
+       struct iommu_resv_region *region;
+       phys_addr_t start = new->start;
+       phys_addr_t end = new->start + new->length - 1;
+       struct list_head *pos = regions->next;
+
+       while (pos != regions) {
+               struct iommu_resv_region *entry =
+                       list_entry(pos, struct iommu_resv_region, list);
+               phys_addr_t a = entry->start;
+               phys_addr_t b = entry->start + entry->length - 1;
+               int type = entry->type;
+
+               if (end < a) {
+                       goto insert;
+               } else if (start > b) {
+                       pos = pos->next;
+               } else if ((start >= a) && (end <= b)) {
+                       if (new->type == type)
+                               goto done;
+                       else
+                               pos = pos->next;
+               } else {
+                       if (new->type == type) {
+                               phys_addr_t new_start = min(a, start);
+                               phys_addr_t new_end = max(b, end);
+
+                               list_del(&entry->list);
+                               entry->start = new_start;
+                               entry->length = new_end - new_start + 1;
+                               iommu_insert_resv_region(entry, regions);
+                       } else {
+                               pos = pos->next;
+                       }
+               }
+       }
+insert:
+       region = iommu_alloc_resv_region(new->start, new->length,
+                                        new->prot, new->type);
+       if (!region)
+               return -ENOMEM;
+
+       list_add_tail(&region->list, pos);
+done:
+       return 0;
+}
+
+static int
+iommu_insert_device_resv_regions(struct list_head *dev_resv_regions,
+                                struct list_head *group_resv_regions)
+{
+       struct iommu_resv_region *entry;
+       int ret;
+
+       list_for_each_entry(entry, dev_resv_regions, list) {
+               ret = iommu_insert_resv_region(entry, group_resv_regions);
+               if (ret)
+                       break;
+       }
+       return ret;
+}
+
+int iommu_get_group_resv_regions(struct iommu_group *group,
+                                struct list_head *head)
+{
+       struct iommu_device *device;
+       int ret = 0;
+
+       mutex_lock(&group->mutex);
+       list_for_each_entry(device, &group->devices, list) {
+               struct list_head dev_resv_regions;
+
+               INIT_LIST_HEAD(&dev_resv_regions);
+               iommu_get_resv_regions(device->dev, &dev_resv_regions);
+               ret = iommu_insert_device_resv_regions(&dev_resv_regions, head);
+               iommu_put_resv_regions(device->dev, &dev_resv_regions);
+               if (ret)
+                       break;
+       }
+       mutex_unlock(&group->mutex);
+       return ret;
+}
+EXPORT_SYMBOL_GPL(iommu_get_group_resv_regions);
+
+static ssize_t iommu_group_show_resv_regions(struct iommu_group *group,
+                                            char *buf)
+{
+       struct iommu_resv_region *region, *next;
+       struct list_head group_resv_regions;
+       char *str = buf;
+
+       INIT_LIST_HEAD(&group_resv_regions);
+       iommu_get_group_resv_regions(group, &group_resv_regions);
+
+       list_for_each_entry_safe(region, next, &group_resv_regions, list) {
+               str += sprintf(str, "0x%016llx 0x%016llx %s\n",
+                              (long long int)region->start,
+                              (long long int)(region->start +
+                                               region->length - 1),
+                              iommu_group_resv_type_string[region->type]);
+               kfree(region);
+       }
+
+       return (str - buf);
+}
+
 static IOMMU_GROUP_ATTR(name, S_IRUGO, iommu_group_show_name, NULL);
 
+static IOMMU_GROUP_ATTR(reserved_regions, 0444,
+                       iommu_group_show_resv_regions, NULL);
+
 static void iommu_group_release(struct kobject *kobj)
 {
        struct iommu_group *group = to_iommu_group(kobj);
@@ -212,6 +355,11 @@ struct iommu_group *iommu_group_alloc(vo
         */
        kobject_put(&group->kobj);
 
+       ret = iommu_group_create_file(group,
+                                     &iommu_group_attr_reserved_regions);
+       if (ret)
+               return ERR_PTR(ret);
+
        pr_debug("Allocated group %d\n", group->id);
 
        return group;
@@ -318,7 +466,7 @@ static int iommu_group_create_direct_map
                                              struct device *dev)
 {
        struct iommu_domain *domain = group->default_domain;
-       struct iommu_dm_region *entry;
+       struct iommu_resv_region *entry;
        struct list_head mappings;
        unsigned long pg_size;
        int ret = 0;
@@ -331,18 +479,21 @@ static int iommu_group_create_direct_map
        pg_size = 1UL << __ffs(domain->pgsize_bitmap);
        INIT_LIST_HEAD(&mappings);
 
-       iommu_get_dm_regions(dev, &mappings);
+       iommu_get_resv_regions(dev, &mappings);
 
        /* We need to consider overlapping regions for different devices */
        list_for_each_entry(entry, &mappings, list) {
                dma_addr_t start, end, addr;
 
-               if (domain->ops->apply_dm_region)
-                       domain->ops->apply_dm_region(dev, domain, entry);
+               if (domain->ops->apply_resv_region)
+                       domain->ops->apply_resv_region(dev, domain, entry);
 
                start = ALIGN(entry->start, pg_size);
                end   = ALIGN(entry->start + entry->length, pg_size);
 
+               if (entry->type != IOMMU_RESV_DIRECT)
+                       continue;
+
                for (addr = start; addr < end; addr += pg_size) {
                        phys_addr_t phys_addr;
 
@@ -358,7 +509,7 @@ static int iommu_group_create_direct_map
        }
 
 out:
-       iommu_put_dm_regions(dev, &mappings);
+       iommu_put_resv_regions(dev, &mappings);
 
        return ret;
 }
@@ -563,6 +714,19 @@ struct iommu_group *iommu_group_get(stru
 EXPORT_SYMBOL_GPL(iommu_group_get);
 
 /**
+ * iommu_group_ref_get - Increment reference on a group
+ * @group: the group to use, must not be NULL
+ *
+ * This function is called by iommu drivers to take additional references on an
+ * existing group.  Returns the given group for convenience.
+ */
+struct iommu_group *iommu_group_ref_get(struct iommu_group *group)
+{
+       kobject_get(group->devices_kobj);
+       return group;
+}
+
+/**
  * iommu_group_put - Decrement group reference
  * @group: the group to use
  *
@@ -845,10 +1009,19 @@ struct iommu_group *iommu_group_get_for_
         * IOMMU driver.
         */
        if (!group->default_domain) {
-               group->default_domain = __iommu_domain_alloc(dev->bus,
-                                                            IOMMU_DOMAIN_DMA);
+               struct iommu_domain *dom;
+
+               dom = __iommu_domain_alloc(dev->bus, iommu_def_domain_type);
+               if (!dom && iommu_def_domain_type != IOMMU_DOMAIN_DMA) {
+                       dev_warn(dev,
+                                "failed to allocate default IOMMU domain of type %u; falling back to IOMMU_DOMAIN_DMA",
+                                iommu_def_domain_type);
+                       dom = __iommu_domain_alloc(dev->bus, IOMMU_DOMAIN_DMA);
+               }
+
+               group->default_domain = dom;
                if (!group->domain)
-                       group->domain = group->default_domain;
+                       group->domain = dom;
        }
 
        ret = iommu_group_add_device(group, dev);
@@ -1557,20 +1730,38 @@ int iommu_domain_set_attr(struct iommu_d
 }
 EXPORT_SYMBOL_GPL(iommu_domain_set_attr);
 
-void iommu_get_dm_regions(struct device *dev, struct list_head *list)
+void iommu_get_resv_regions(struct device *dev, struct list_head *list)
 {
        const struct iommu_ops *ops = dev->bus->iommu_ops;
 
-       if (ops && ops->get_dm_regions)
-               ops->get_dm_regions(dev, list);
+       if (ops && ops->get_resv_regions)
+               ops->get_resv_regions(dev, list);
 }
 
-void iommu_put_dm_regions(struct device *dev, struct list_head *list)
+void iommu_put_resv_regions(struct device *dev, struct list_head *list)
 {
        const struct iommu_ops *ops = dev->bus->iommu_ops;
 
-       if (ops && ops->put_dm_regions)
-               ops->put_dm_regions(dev, list);
+       if (ops && ops->put_resv_regions)
+               ops->put_resv_regions(dev, list);
+}
+
+struct iommu_resv_region *iommu_alloc_resv_region(phys_addr_t start,
+                                                 size_t length, int prot,
+                                                 enum iommu_resv_type type)
+{
+       struct iommu_resv_region *region;
+
+       region = kzalloc(sizeof(*region), GFP_KERNEL);
+       if (!region)
+               return NULL;
+
+       INIT_LIST_HEAD(&region->list);
+       region->start = start;
+       region->length = length;
+       region->prot = prot;
+       region->type = type;
+       return region;
 }
 
 /* Request that a device is direct mapped by the IOMMU */
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -410,6 +410,8 @@ static struct iommu_group *mtk_iommu_dev
                data->m4u_group = iommu_group_alloc();
                if (IS_ERR(data->m4u_group))
                        dev_err(dev, "Failed to allocate M4U IOMMU group\n");
+       } else {
+               iommu_group_ref_get(data->m4u_group);
        }
        return data->m4u_group;
 }
--- a/drivers/iommu/mtk_iommu_v1.c
+++ b/drivers/iommu/mtk_iommu_v1.c
@@ -502,6 +502,8 @@ static struct iommu_group *mtk_iommu_dev
                data->m4u_group = iommu_group_alloc();
                if (IS_ERR(data->m4u_group))
                        dev_err(dev, "Failed to allocate M4U IOMMU group\n");
+       } else {
+               iommu_group_ref_get(data->m4u_group);
        }
        return data->m4u_group;
 }
--- a/include/linux/dma-iommu.h
+++ b/include/linux/dma-iommu.h
@@ -28,6 +28,7 @@ int iommu_dma_init(void);
 
 /* Domain management interface for IOMMU drivers */
 int iommu_get_dma_cookie(struct iommu_domain *domain);
+int iommu_get_msi_cookie(struct iommu_domain *domain, dma_addr_t base);
 void iommu_put_dma_cookie(struct iommu_domain *domain);
 
 /* Setup call for arch DMA mapping code */
@@ -67,6 +68,7 @@ int iommu_dma_mapping_error(struct devic
 
 /* The DMA API isn't _quite_ the whole story, though... */
 void iommu_dma_map_msi_msg(int irq, struct msi_msg *msg);
+void iommu_dma_get_resv_regions(struct device *dev, struct list_head *list);
 
 #else
 
@@ -83,6 +85,11 @@ static inline int iommu_get_dma_cookie(s
        return -ENODEV;
 }
 
+static inline int iommu_get_msi_cookie(struct iommu_domain *domain, dma_addr_t base)
+{
+       return -ENODEV;
+}
+
 static inline void iommu_put_dma_cookie(struct iommu_domain *domain)
 {
 }
@@ -91,6 +98,10 @@ static inline void iommu_dma_map_msi_msg
 {
 }
 
+static inline void iommu_dma_get_resv_regions(struct device *dev, struct list_head *list)
+{
+}
+
 #endif /* CONFIG_IOMMU_DMA */
 #endif /* __KERNEL__ */
 #endif /* __DMA_IOMMU_H */
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -117,18 +117,32 @@ enum iommu_attr {
        DOMAIN_ATTR_MAX,
 };
 
+/* These are the possible reserved region types */
+enum iommu_resv_type {
+       /* Memory regions which must be mapped 1:1 at all times */
+       IOMMU_RESV_DIRECT,
+       /* Arbitrary "never map this or give it to a device" address ranges */
+       IOMMU_RESV_RESERVED,
+       /* Hardware MSI region (untranslated) */
+       IOMMU_RESV_MSI,
+       /* Software-managed MSI translation window */
+       IOMMU_RESV_SW_MSI,
+};
+
 /**
- * struct iommu_dm_region - descriptor for a direct mapped memory region
+ * struct iommu_resv_region - descriptor for a reserved memory region
  * @list: Linked list pointers
  * @start: System physical start address of the region
  * @length: Length of the region in bytes
  * @prot: IOMMU Protection flags (READ/WRITE/...)
+ * @type: Type of the reserved region
  */
-struct iommu_dm_region {
+struct iommu_resv_region {
        struct list_head        list;
        phys_addr_t             start;
        size_t                  length;
        int                     prot;
+       enum iommu_resv_type    type;
 };
 
 #ifdef CONFIG_IOMMU_API
@@ -150,9 +164,9 @@ struct iommu_dm_region {
  * @device_group: find iommu group for a particular device
  * @domain_get_attr: Query domain attributes
  * @domain_set_attr: Change domain attributes
- * @get_dm_regions: Request list of direct mapping requirements for a device
- * @put_dm_regions: Free list of direct mapping requirements for a device
- * @apply_dm_region: Temporary helper call-back for iova reserved ranges
+ * @get_resv_regions: Request list of reserved regions for a device
+ * @put_resv_regions: Free list of reserved regions for a device
+ * @apply_resv_region: Temporary helper call-back for iova reserved ranges
  * @domain_window_enable: Configure and enable a particular window for a domain
  * @domain_window_disable: Disable a particular window for a domain
  * @domain_set_windows: Set the number of windows for a domain
@@ -184,11 +198,12 @@ struct iommu_ops {
        int (*domain_set_attr)(struct iommu_domain *domain,
                               enum iommu_attr attr, void *data);
 
-       /* Request/Free a list of direct mapping requirements for a device */
-       void (*get_dm_regions)(struct device *dev, struct list_head *list);
-       void (*put_dm_regions)(struct device *dev, struct list_head *list);
-       void (*apply_dm_region)(struct device *dev, struct iommu_domain *domain,
-                               struct iommu_dm_region *region);
+       /* Request/Free a list of reserved regions for a device */
+       void (*get_resv_regions)(struct device *dev, struct list_head *list);
+       void (*put_resv_regions)(struct device *dev, struct list_head *list);
+       void (*apply_resv_region)(struct device *dev,
+                                 struct iommu_domain *domain,
+                                 struct iommu_resv_region *region);
 
        /* Window handling functions */
        int (*domain_window_enable)(struct iommu_domain *domain, u32 wnd_nr,
@@ -233,9 +248,14 @@ extern phys_addr_t iommu_iova_to_phys(st
 extern void iommu_set_fault_handler(struct iommu_domain *domain,
                        iommu_fault_handler_t handler, void *token);
 
-extern void iommu_get_dm_regions(struct device *dev, struct list_head *list);
-extern void iommu_put_dm_regions(struct device *dev, struct list_head *list);
+extern void iommu_get_resv_regions(struct device *dev, struct list_head *list);
+extern void iommu_put_resv_regions(struct device *dev, struct list_head *list);
 extern int iommu_request_dm_for_dev(struct device *dev);
+extern struct iommu_resv_region *
+iommu_alloc_resv_region(phys_addr_t start, size_t length, int prot,
+                       enum iommu_resv_type type);
+extern int iommu_get_group_resv_regions(struct iommu_group *group,
+                                       struct list_head *head);
 
 extern int iommu_attach_group(struct iommu_domain *domain,
                              struct iommu_group *group);
@@ -253,6 +273,7 @@ extern void iommu_group_remove_device(st
 extern int iommu_group_for_each_dev(struct iommu_group *group, void *data,
                                    int (*fn)(struct device *, void *));
 extern struct iommu_group *iommu_group_get(struct device *dev);
+extern struct iommu_group *iommu_group_ref_get(struct iommu_group *group);
 extern void iommu_group_put(struct iommu_group *group);
 extern int iommu_group_register_notifier(struct iommu_group *group,
                                         struct notifier_block *nb);
@@ -439,16 +460,22 @@ static inline void iommu_set_fault_handl
 {
 }
 
-static inline void iommu_get_dm_regions(struct device *dev,
+static inline void iommu_get_resv_regions(struct device *dev,
                                        struct list_head *list)
 {
 }
 
-static inline void iommu_put_dm_regions(struct device *dev,
+static inline void iommu_put_resv_regions(struct device *dev,
                                        struct list_head *list)
 {
 }
 
+static inline int iommu_get_group_resv_regions(struct iommu_group *group,
+                                              struct list_head *head)
+{
+       return -ENODEV;
+}
+
 static inline int iommu_request_dm_for_dev(struct device *dev)
 {
        return -ENODEV;