linux/drivers/iommu/arm-smmu-impl.c
Robin Murphy 3995e18689 iommu/arm-smmu: Add configuration implementation hook
Probing the ID registers and setting up the SMMU configuration is an
area where overrides and workarounds may well be needed. Indeed, the
Cavium workaround detection lives there at the moment, so let's break
that out.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-19 16:52:48 +01:00

92 lines
2.1 KiB
C

// 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/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 */
const struct arm_smmu_impl calxeda_impl = {
.read_reg = arm_smmu_read_ns,
.write_reg = arm_smmu_write_ns,
};
static int cavium_cfg_probe(struct arm_smmu_device *smmu)
{
static atomic_t context_count = ATOMIC_INIT(0);
/*
* Cavium CN88xx erratum #27704.
* Ensure ASID and VMID allocation is unique across all SMMUs in
* the system.
*/
smmu->cavium_id_base = atomic_fetch_add(smmu->num_context_banks,
&context_count);
dev_notice(smmu->dev, "\tenabling workaround for Cavium erratum 27704\n");
return 0;
}
const struct arm_smmu_impl cavium_impl = {
.cfg_probe = cavium_cfg_probe,
};
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 CAVIUM_SMMUV2:
smmu->impl = &cavium_impl;
break;
default:
break;
}
if (of_property_read_bool(smmu->dev->of_node,
"calxeda,smmu-secure-config-access"))
smmu->impl = &calxeda_impl;
return smmu;
}