[PATCH 3/5] iommu/amd: x2apic mode: setup the INTX registers on mask/unmask

From: Maxim Levitsky
Date: Tue Nov 23 2021 - 11:11:02 EST


This is more logically correct and will also allow us to
to use mask/unmask logic to restore INTX setttings after
the resume from s3/s4.

Fixes: 66929812955bb ("iommu/amd: Add support for X2APIC IOMMU interrupts")

Signed-off-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx>
---
drivers/iommu/amd/init.c | 65 ++++++++++++++++++++--------------------
1 file changed, 33 insertions(+), 32 deletions(-)

diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c
index b905604f434e1..9e895bb8086a6 100644
--- a/drivers/iommu/amd/init.c
+++ b/drivers/iommu/amd/init.c
@@ -2015,48 +2015,18 @@ union intcapxt {
};
} __attribute__ ((packed));

-/*
- * There isn't really any need to mask/unmask at the irqchip level because
- * the 64-bit INTCAPXT registers can be updated atomically without tearing
- * when the affinity is being updated.
- */
-static void intcapxt_unmask_irq(struct irq_data *data)
-{
-}
-
-static void intcapxt_mask_irq(struct irq_data *data)
-{
-}

static struct irq_chip intcapxt_controller;

static int intcapxt_irqdomain_activate(struct irq_domain *domain,
struct irq_data *irqd, bool reserve)
{
- struct amd_iommu *iommu = irqd->chip_data;
- struct irq_cfg *cfg = irqd_cfg(irqd);
- union intcapxt xt;
-
- xt.capxt = 0ULL;
- xt.dest_mode_logical = apic->dest_mode_logical;
- xt.vector = cfg->vector;
- xt.destid_0_23 = cfg->dest_apicid & GENMASK(23, 0);
- xt.destid_24_31 = cfg->dest_apicid >> 24;
-
- /**
- * Current IOMMU implemtation uses the same IRQ for all
- * 3 IOMMU interrupts.
- */
- writeq(xt.capxt, iommu->mmio_base + MMIO_INTCAPXT_EVT_OFFSET);
- writeq(xt.capxt, iommu->mmio_base + MMIO_INTCAPXT_PPR_OFFSET);
- writeq(xt.capxt, iommu->mmio_base + MMIO_INTCAPXT_GALOG_OFFSET);
return 0;
}

static void intcapxt_irqdomain_deactivate(struct irq_domain *domain,
struct irq_data *irqd)
{
- intcapxt_mask_irq(irqd);
}


@@ -2090,6 +2060,38 @@ static void intcapxt_irqdomain_free(struct irq_domain *domain, unsigned int virq
irq_domain_free_irqs_top(domain, virq, nr_irqs);
}

+
+static void intcapxt_unmask_irq(struct irq_data *irqd)
+{
+ struct amd_iommu *iommu = irqd->chip_data;
+ struct irq_cfg *cfg = irqd_cfg(irqd);
+ union intcapxt xt;
+
+ xt.capxt = 0ULL;
+ xt.dest_mode_logical = apic->dest_mode_logical;
+ xt.vector = cfg->vector;
+ xt.destid_0_23 = cfg->dest_apicid & GENMASK(23, 0);
+ xt.destid_24_31 = cfg->dest_apicid >> 24;
+
+ /**
+ * Current IOMMU implementation uses the same IRQ for all
+ * 3 IOMMU interrupts.
+ */
+ writeq(xt.capxt, iommu->mmio_base + MMIO_INTCAPXT_EVT_OFFSET);
+ writeq(xt.capxt, iommu->mmio_base + MMIO_INTCAPXT_PPR_OFFSET);
+ writeq(xt.capxt, iommu->mmio_base + MMIO_INTCAPXT_GALOG_OFFSET);
+}
+
+static void intcapxt_mask_irq(struct irq_data *irqd)
+{
+ struct amd_iommu *iommu = irqd->chip_data;
+
+ writeq(0, iommu->mmio_base + MMIO_INTCAPXT_EVT_OFFSET);
+ writeq(0, iommu->mmio_base + MMIO_INTCAPXT_PPR_OFFSET);
+ writeq(0, iommu->mmio_base + MMIO_INTCAPXT_GALOG_OFFSET);
+}
+
+
static int intcapxt_set_affinity(struct irq_data *irqd,
const struct cpumask *mask, bool force)
{
@@ -2099,8 +2101,7 @@ static int intcapxt_set_affinity(struct irq_data *irqd,
ret = parent->chip->irq_set_affinity(parent, mask, force);
if (ret < 0 || ret == IRQ_SET_MASK_OK_DONE)
return ret;
-
- return intcapxt_irqdomain_activate(irqd->domain, irqd, false);
+ return 0;
}

static struct irq_chip intcapxt_controller = {
--
2.26.3