diff options
Diffstat (limited to 'drivers/iommu/arm-smmu-impl.c')
| -rw-r--r-- | drivers/iommu/arm-smmu-impl.c | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/drivers/iommu/arm-smmu-impl.c b/drivers/iommu/arm-smmu-impl.c new file mode 100644 index 000000000000..5c87a38620c4 --- /dev/null +++ b/drivers/iommu/arm-smmu-impl.c @@ -0,0 +1,174 @@ +// SPDX-License-Identifier: GPL-2.0-only +// Miscellaneous Arm SMMU implementation and integration quirks +// Copyright (C) 2019 Arm Limited + +#define pr_fmt(fmt) "arm-smmu: " fmt + +#include <linux/bitfield.h> +#include <linux/of.h> + +#include "arm-smmu.h" + + +static int arm_smmu_gr0_ns(int offset) +{ + switch(offset) { + case ARM_SMMU_GR0_sCR0: + case ARM_SMMU_GR0_sACR: + case ARM_SMMU_GR0_sGFSR: + case ARM_SMMU_GR0_sGFSYNR0: + case ARM_SMMU_GR0_sGFSYNR1: + case ARM_SMMU_GR0_sGFSYNR2: + return offset + 0x400; + default: + return offset; + } +} + +static u32 arm_smmu_read_ns(struct arm_smmu_device *smmu, int page, + int offset) +{ + if (page == ARM_SMMU_GR0) + offset = arm_smmu_gr0_ns(offset); + return readl_relaxed(arm_smmu_page(smmu, page) + offset); +} + +static void arm_smmu_write_ns(struct arm_smmu_device *smmu, int page, + int offset, u32 val) +{ + if (page == ARM_SMMU_GR0) + offset = arm_smmu_gr0_ns(offset); + writel_relaxed(val, arm_smmu_page(smmu, page) + offset); +} + +/* Since we don't care for sGFAR, we can do without 64-bit accessors */ +static const struct arm_smmu_impl calxeda_impl = { + .read_reg = arm_smmu_read_ns, + .write_reg = arm_smmu_write_ns, +}; + + +struct cavium_smmu { + struct arm_smmu_device smmu; + u32 id_base; +}; + +static int cavium_cfg_probe(struct arm_smmu_device *smmu) +{ + static atomic_t context_count = ATOMIC_INIT(0); + struct cavium_smmu *cs = container_of(smmu, struct cavium_smmu, smmu); + /* + * Cavium CN88xx erratum #27704. + * Ensure ASID and VMID allocation is unique across all SMMUs in + * the system. + */ + cs->id_base = atomic_fetch_add(smmu->num_context_banks, &context_count); + dev_notice(smmu->dev, "\tenabling workaround for Cavium erratum 27704\n"); + + return 0; +} + +static int cavium_init_context(struct arm_smmu_domain *smmu_domain) +{ + struct cavium_smmu *cs = container_of(smmu_domain->smmu, + struct cavium_smmu, smmu); + + if (smmu_domain->stage == ARM_SMMU_DOMAIN_S2) + smmu_domain->cfg.vmid += cs->id_base; + else + smmu_domain->cfg.asid += cs->id_base; + + return 0; +} + +static const struct arm_smmu_impl cavium_impl = { + .cfg_probe = cavium_cfg_probe, + .init_context = cavium_init_context, +}; + +static struct arm_smmu_device *cavium_smmu_impl_init(struct arm_smmu_device *smmu) +{ + struct cavium_smmu *cs; + + cs = devm_kzalloc(smmu->dev, sizeof(*cs), GFP_KERNEL); + if (!cs) + return ERR_PTR(-ENOMEM); + + cs->smmu = *smmu; + cs->smmu.impl = &cavium_impl; + + devm_kfree(smmu->dev, smmu); + + return &cs->smmu; +} + + +#define ARM_MMU500_ACTLR_CPRE (1 << 1) + +#define ARM_MMU500_ACR_CACHE_LOCK (1 << 26) +#define ARM_MMU500_ACR_S2CRB_TLBEN (1 << 10) +#define ARM_MMU500_ACR_SMTNMB_TLBEN (1 << 8) + +static int arm_mmu500_reset(struct arm_smmu_device *smmu) +{ + u32 reg, major; + int i; + /* + * On MMU-500 r2p0 onwards we need to clear ACR.CACHE_LOCK before + * writes to the context bank ACTLRs will stick. And we just hope that + * Secure has also cleared SACR.CACHE_LOCK for this to take effect... + */ + reg = arm_smmu_gr0_read(smmu, ARM_SMMU_GR0_ID7); + major = FIELD_GET(ID7_MAJOR, reg); + reg = arm_smmu_gr0_read(smmu, ARM_SMMU_GR0_sACR); + 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 | ARM_MMU500_ACR_S2CRB_TLBEN; + arm_smmu_gr0_write(smmu, ARM_SMMU_GR0_sACR, reg); + + /* + * Disable MMU-500's not-particularly-beneficial next-page + * prefetcher for the sake of errata #841119 and #826419. + */ + for (i = 0; i < smmu->num_context_banks; ++i) { + reg = arm_smmu_cb_read(smmu, i, ARM_SMMU_CB_ACTLR); + reg &= ~ARM_MMU500_ACTLR_CPRE; + arm_smmu_cb_write(smmu, i, ARM_SMMU_CB_ACTLR, reg); + } + + return 0; +} + +static const struct arm_smmu_impl arm_mmu500_impl = { + .reset = arm_mmu500_reset, +}; + + +struct arm_smmu_device *arm_smmu_impl_init(struct arm_smmu_device *smmu) +{ + /* + * We will inevitably have to combine model-specific implementation + * quirks with platform-specific integration quirks, but everything + * we currently support happens to work out as straightforward + * mutually-exclusive assignments. + */ + switch (smmu->model) { + case ARM_MMU500: + smmu->impl = &arm_mmu500_impl; + break; + case CAVIUM_SMMUV2: + return cavium_smmu_impl_init(smmu); + default: + break; + } + + if (of_property_read_bool(smmu->dev->of_node, + "calxeda,smmu-secure-config-access")) + smmu->impl = &calxeda_impl; + + return smmu; +} |