drivers/iommu/arm-smmu-impl.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 // Miscellaneous Arm SMMU implementation and integration quirks
   3 // Copyright (C) 2019 Arm Limited
   4
   5 #define pr_fmt(fmt) "arm-smmu: " fmt
   6
   7 #include <linux/bitfield.h>
   8 #include <linux/of.h>
   9
  10 #include "arm-smmu.h"
  11
  12
  13 static int arm_smmu_gr0_ns(int offset)
  14 {
  15         switch(offset) {
  16         case ARM_SMMU_GR0_sCR0:
  17         case ARM_SMMU_GR0_sACR:
  18         case ARM_SMMU_GR0_sGFSR:
  19         case ARM_SMMU_GR0_sGFSYNR0:
  20         case ARM_SMMU_GR0_sGFSYNR1:
  21         case ARM_SMMU_GR0_sGFSYNR2:
  22                 return offset + 0x400;
  23         default:
  24                 return offset;
  25         }
  26 }
  27
  28 static u32 arm_smmu_read_ns(struct arm_smmu_device *smmu, int page,
  29                             int offset)
  30 {
  31         if (page == ARM_SMMU_GR0)
  32                 offset = arm_smmu_gr0_ns(offset);
  33         return readl_relaxed(arm_smmu_page(smmu, page) + offset);
  34 }
  35
  36 static void arm_smmu_write_ns(struct arm_smmu_device *smmu, int page,
  37                               int offset, u32 val)
  38 {
  39         if (page == ARM_SMMU_GR0)
  40                 offset = arm_smmu_gr0_ns(offset);
  41         writel_relaxed(val, arm_smmu_page(smmu, page) + offset);
  42 }
  43
  44 /* Since we don't care for sGFAR, we can do without 64-bit accessors */
  45 static const struct arm_smmu_impl calxeda_impl = {
  46         .read_reg = arm_smmu_read_ns,
  47         .write_reg = arm_smmu_write_ns,
  48 };
  49
  50
  51 struct cavium_smmu {
  52         struct arm_smmu_device smmu;
  53         u32 id_base;
  54 };
  55
  56 static int cavium_cfg_probe(struct arm_smmu_device *smmu)
  57 {
  58         static atomic_t context_count = ATOMIC_INIT(0);
  59         struct cavium_smmu *cs = container_of(smmu, struct cavium_smmu, smmu);
  60         /*
  61          * Cavium CN88xx erratum #27704.
  62          * Ensure ASID and VMID allocation is unique across all SMMUs in
  63          * the system.
  64          */
  65         cs->id_base = atomic_fetch_add(smmu->num_context_banks, &context_count);
  66         dev_notice(smmu->dev, "\tenabling workaround for Cavium erratum 27704\n");
  67
  68         return 0;
  69 }
  70
  71 static int cavium_init_context(struct arm_smmu_domain *smmu_domain)
  72 {
  73         struct cavium_smmu *cs = container_of(smmu_domain->smmu,
  74                                               struct cavium_smmu, smmu);
  75
  76         if (smmu_domain->stage == ARM_SMMU_DOMAIN_S2)
  77                 smmu_domain->cfg.vmid += cs->id_base;
  78         else
  79                 smmu_domain->cfg.asid += cs->id_base;
  80
  81         return 0;
  82 }
  83
  84 static const struct arm_smmu_impl cavium_impl = {
  85         .cfg_probe = cavium_cfg_probe,
  86         .init_context = cavium_init_context,
  87 };
  88
  89 static struct arm_smmu_device *cavium_smmu_impl_init(struct arm_smmu_device *smmu)
  90 {
  91         struct cavium_smmu *cs;
  92
  93         cs = devm_kzalloc(smmu->dev, sizeof(*cs), GFP_KERNEL);
  94         if (!cs)
  95                 return ERR_PTR(-ENOMEM);
  96
  97         cs->smmu = *smmu;
  98         cs->smmu.impl = &cavium_impl;
  99
 100         devm_kfree(smmu->dev, smmu);
 101
 102         return &cs->smmu;
 103 }
 104
 105
 106 #define ARM_MMU500_ACTLR_CPRE           (1 << 1)
 107
 108 #define ARM_MMU500_ACR_CACHE_LOCK       (1 << 26)
 109 #define ARM_MMU500_ACR_S2CRB_TLBEN      (1 << 10)
 110 #define ARM_MMU500_ACR_SMTNMB_TLBEN     (1 << 8)
 111
 112 int arm_mmu500_reset(struct arm_smmu_device *smmu)
 113 {
 114         u32 reg, major;
 115         int i;
 116         /*
 117          * On MMU-500 r2p0 onwards we need to clear ACR.CACHE_LOCK before
 118          * writes to the context bank ACTLRs will stick. And we just hope that
 119          * Secure has also cleared SACR.CACHE_LOCK for this to take effect...
 120          */
 121         reg = arm_smmu_gr0_read(smmu, ARM_SMMU_GR0_ID7);
 122         major = FIELD_GET(ID7_MAJOR, reg);
 123         reg = arm_smmu_gr0_read(smmu, ARM_SMMU_GR0_sACR);
 124         if (major >= 2)
 125                 reg &= ~ARM_MMU500_ACR_CACHE_LOCK;
 126         /*
 127          * Allow unmatched Stream IDs to allocate bypass
 128          * TLB entries for reduced latency.
 129          */
 130         reg |= ARM_MMU500_ACR_SMTNMB_TLBEN | ARM_MMU500_ACR_S2CRB_TLBEN;
 131         arm_smmu_gr0_write(smmu, ARM_SMMU_GR0_sACR, reg);
 132
 133         /*
 134          * Disable MMU-500's not-particularly-beneficial next-page
 135          * prefetcher for the sake of errata #841119 and #826419.
 136          */
 137         for (i = 0; i < smmu->num_context_banks; ++i) {
 138                 reg = arm_smmu_cb_read(smmu, i, ARM_SMMU_CB_ACTLR);
 139                 reg &= ~ARM_MMU500_ACTLR_CPRE;
 140                 arm_smmu_cb_write(smmu, i, ARM_SMMU_CB_ACTLR, reg);
 141         }
 142
 143         return 0;
 144 }
 145
 146 static const struct arm_smmu_impl arm_mmu500_impl = {
 147         .reset = arm_mmu500_reset,
 148 };
 149
 150
 151 struct arm_smmu_device *arm_smmu_impl_init(struct arm_smmu_device *smmu)
 152 {
 153         /*
 154          * We will inevitably have to combine model-specific implementation
 155          * quirks with platform-specific integration quirks, but everything
 156          * we currently support happens to work out as straightforward
 157          * mutually-exclusive assignments.
 158          */
 159         switch (smmu->model) {
 160         case ARM_MMU500:
 161                 smmu->impl = &arm_mmu500_impl;
 162                 break;
 163         case CAVIUM_SMMUV2:
 164                 return cavium_smmu_impl_init(smmu);
 165         default:
 166                 break;
 167         }
 168
 169         if (of_property_read_bool(smmu->dev->of_node,
 170                                   "calxeda,smmu-secure-config-access"))
 171                 smmu->impl = &calxeda_impl;
 172
 173         if (of_device_is_compatible(smmu->dev->of_node, "qcom,sdm845-smmu-500"))
 174                 return qcom_smmu_impl_init(smmu);
 175
 176         return smmu;
 177 }