iommu/arm-smmu: Add support for MSI on SMMUv3
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>
diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index 970d78d..5a36ef7 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -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 @@
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 @@
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 @@
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 @@
}
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 @@
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: