Create an auxiliary device for HPM when the IOMMU supports a
hardware performance monitor.
Suggested-by: Samuel Holland <samuel.holland@sifive.com>
Signed-off-by: Zong Li <zong.li@sifive.com>
---
drivers/iommu/riscv/iommu.c | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)
diff --git a/drivers/iommu/riscv/iommu.c b/drivers/iommu/riscv/iommu.c
index d9429097a2b5..7cdb80d4343d 100644
--- a/drivers/iommu/riscv/iommu.c
+++ b/drivers/iommu/riscv/iommu.c
@@ -14,6 +14,7 @@
#include <linux/acpi.h>
#include <linux/acpi_rimt.h>
+#include <linux/auxiliary_bus.h>
#include <linux/compiler.h>
#include <linux/crash_dump.h>
#include <linux/init.h>
@@ -559,6 +560,22 @@ static irqreturn_t riscv_iommu_fltq_process(int irq, void *data)
return IRQ_HANDLED;
}
+/*
+ * IOMMU Hardware performance monitor
+ */
+static int riscv_iommu_hpm_enable(struct riscv_iommu_device *iommu)
+{
+ struct auxiliary_device *auxdev;
+
+ /* TODO: for custom event support, the modname should come from compatible */
+ auxdev = __devm_auxiliary_device_create(iommu->dev, KBUILD_MODNAME,
+ "pmu", iommu, 0);
+ if (!auxdev)
+ return -ENODEV;
+
+ return 0;
+}
+
/* Lookup and initialize device context info structure. */
static struct riscv_iommu_dc *riscv_iommu_get_dc(struct riscv_iommu_device *iommu,
unsigned int devid)
@@ -1669,6 +1686,9 @@ int riscv_iommu_init(struct riscv_iommu_device *iommu)
goto err_remove_sysfs;
}
+ if (iommu->caps & RISCV_IOMMU_CAPABILITIES_HPM)
+ riscv_iommu_hpm_enable(iommu);
+
return 0;
err_remove_sysfs:
--
2.43.7