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iommu/arm-smmu: Add support for MSI on SMMUv3

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Despite being a platform device, the SMMUv3 is capable of signaling
interrupts using MSIs. Hook it into the platform MSI framework and
enjoy faults being reported in a new and exciting way.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
[will: tidied up the binding example and reworked most of the code]
Signed-off-by: Will Deacon <will.deacon@arm.com>
This commit is contained in:
Marc Zyngier 2015-10-13 18:32:30 +01:00 committed by Will Deacon
parent c88ae5de71
commit 166bdbd231
3 changed files with 117 additions and 8 deletions
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19
Documentation/devicetree/bindings/iommu/arm,smmu-v3.txt
View file

@ -36,5 +36,24 @@ the PCIe specification.
NOTE: this only applies to the SMMU itself, not
masters connected upstream of the SMMU.
- msi-parent : See the generic MSI binding described in
devicetree/bindings/interrupt-controller/msi.txt
for a description of the msi-parent property.
- hisilicon,broken-prefetch-cmd
: Avoid sending CMD_PREFETCH_* commands to the SMMU.
** Example
smmu@2b400000 {
compatible = "arm,smmu-v3";
reg = <0x0 0x2b400000 0x0 0x20000>;
interrupts = <GIC_SPI 74 IRQ_TYPE_EDGE_RISING>,
<GIC_SPI 75 IRQ_TYPE_EDGE_RISING>,
<GIC_SPI 77 IRQ_TYPE_EDGE_RISING>,
<GIC_SPI 79 IRQ_TYPE_EDGE_RISING>;
interrupt-names = "eventq", "priq", "cmdq-sync", "gerror";
dma-coherent;
#iommu-cells = <0>;
msi-parent = <&its 0xff0000>;
};

1
drivers/iommu/Kconfig
View file

@ -362,6 +362,7 @@ config ARM_SMMU_V3
depends on ARM64 && PCI
select IOMMU_API
select IOMMU_IO_PGTABLE_LPAE
select GENERIC_MSI_IRQ_DOMAIN
help
Support for implementations of the ARM System MMU architecture
version 3 providing translation support to a PCIe root complex.

105
drivers/iommu/arm-smmu-v3.c
View file

@ -26,6 +26,7 @@
#include <linux/iommu.h>
#include <linux/iopoll.h>
#include <linux/module.h>
#include <linux/msi.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_platform.h>
@ -402,6 +403,31 @@ enum pri_resp {
PRI_RESP_SUCC,
};
enum arm_smmu_msi_index {
EVTQ_MSI_INDEX,
GERROR_MSI_INDEX,
PRIQ_MSI_INDEX,
ARM_SMMU_MAX_MSIS,
};
static phys_addr_t arm_smmu_msi_cfg[ARM_SMMU_MAX_MSIS][3] = {
[EVTQ_MSI_INDEX] = {
ARM_SMMU_EVTQ_IRQ_CFG0,
ARM_SMMU_EVTQ_IRQ_CFG1,
ARM_SMMU_EVTQ_IRQ_CFG2,
},
[GERROR_MSI_INDEX] = {
ARM_SMMU_GERROR_IRQ_CFG0,
ARM_SMMU_GERROR_IRQ_CFG1,
ARM_SMMU_GERROR_IRQ_CFG2,
},
[PRIQ_MSI_INDEX] = {
ARM_SMMU_PRIQ_IRQ_CFG0,
ARM_SMMU_PRIQ_IRQ_CFG1,
ARM_SMMU_PRIQ_IRQ_CFG2,
},
};
struct arm_smmu_cmdq_ent {
/* Common fields */
u8 opcode;
@ -2176,6 +2202,72 @@ static int arm_smmu_write_reg_sync(struct arm_smmu_device *smmu, u32 val,
1, ARM_SMMU_POLL_TIMEOUT_US);
}
static void arm_smmu_free_msis(void *data)
{
struct device *dev = data;
platform_msi_domain_free_irqs(dev);
}
static void arm_smmu_write_msi_msg(struct msi_desc *desc, struct msi_msg *msg)
{
phys_addr_t doorbell;
struct device *dev = msi_desc_to_dev(desc);
struct arm_smmu_device *smmu = dev_get_drvdata(dev);
phys_addr_t *cfg = arm_smmu_msi_cfg[desc->platform.msi_index];
doorbell = (((u64)msg->address_hi) << 32) | msg->address_lo;
doorbell &= MSI_CFG0_ADDR_MASK << MSI_CFG0_ADDR_SHIFT;
writeq_relaxed(doorbell, smmu->base + cfg[0]);
writel_relaxed(msg->data, smmu->base + cfg[1]);
writel_relaxed(MSI_CFG2_MEMATTR_DEVICE_nGnRE, smmu->base + cfg[2]);
}
static void arm_smmu_setup_msis(struct arm_smmu_device *smmu)
{
struct msi_desc *desc;
int ret, nvec = ARM_SMMU_MAX_MSIS;
struct device *dev = smmu->dev;
/* Clear the MSI address regs */
writeq_relaxed(0, smmu->base + ARM_SMMU_GERROR_IRQ_CFG0);
writeq_relaxed(0, smmu->base + ARM_SMMU_EVTQ_IRQ_CFG0);
if (smmu->features & ARM_SMMU_FEAT_PRI)
writeq_relaxed(0, smmu->base + ARM_SMMU_PRIQ_IRQ_CFG0);
else
nvec--;
if (!(smmu->features & ARM_SMMU_FEAT_MSI))
return;
/* Allocate MSIs for evtq, gerror and priq. Ignore cmdq */
ret = platform_msi_domain_alloc_irqs(dev, nvec, arm_smmu_write_msi_msg);
if (ret) {
dev_warn(dev, "failed to allocate MSIs\n");
return;
}
for_each_msi_entry(desc, dev) {
switch (desc->platform.msi_index) {
case EVTQ_MSI_INDEX:
smmu->evtq.q.irq = desc->irq;
break;
case GERROR_MSI_INDEX:
smmu->gerr_irq = desc->irq;
break;
case PRIQ_MSI_INDEX:
smmu->priq.q.irq = desc->irq;
break;
default: /* Unknown */
continue;
}
}
/* Add callback to free MSIs on teardown */
devm_add_action(dev, arm_smmu_free_msis, dev);
}
static int arm_smmu_setup_irqs(struct arm_smmu_device *smmu)
{
int ret, irq;
@ -2189,11 +2281,9 @@ static int arm_smmu_setup_irqs(struct arm_smmu_device *smmu)
return ret;
}
/* Clear the MSI address regs */
writeq_relaxed(0, smmu->base + ARM_SMMU_GERROR_IRQ_CFG0);
writeq_relaxed(0, smmu->base + ARM_SMMU_EVTQ_IRQ_CFG0);
arm_smmu_setup_msis(smmu);
/* Request wired interrupt lines */
/* Request interrupt lines */
irq = smmu->evtq.q.irq;
if (irq) {
ret = devm_request_threaded_irq(smmu->dev, irq,
@ -2222,8 +2312,6 @@ static int arm_smmu_setup_irqs(struct arm_smmu_device *smmu)
}
if (smmu->features & ARM_SMMU_FEAT_PRI) {
writeq_relaxed(0, smmu->base + ARM_SMMU_PRIQ_IRQ_CFG0);
irq = smmu->priq.q.irq;
if (irq) {
ret = devm_request_threaded_irq(smmu->dev, irq,
@ -2597,13 +2685,14 @@ static int arm_smmu_device_dt_probe(struct platform_device *pdev)
if (ret)
return ret;
/* Record our private device structure */
platform_set_drvdata(pdev, smmu);
/* Reset the device */
ret = arm_smmu_device_reset(smmu);
if (ret)
goto out_free_structures;
/* Record our private device structure */
platform_set_drvdata(pdev, smmu);
return 0;
out_free_structures: