[PATCH 07/15] irqchip: GICv3: ITS: irqchip implementation

From: Marc Zyngier
Date: Tue Nov 11 2014 - 10:48:39 EST


The usual methods that are used to present an irqchip to the rest
of the kernel

Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
---
drivers/irqchip/irq-gic-v3-its.c | 77 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 77 insertions(+)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 1082173..c904769 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -40,6 +40,8 @@

#define ITS_FLAGS_CMDQ_NEEDS_FLUSHING (1 << 0)

+#define RDIST_FLAGS_PROPBASE_NEEDS_FLUSHING (1 << 0)
+
/*
* Collection structure - just an ID, and a redistributor address to
* ping. We use one per CPU as a bag of interrupts assigned to this
@@ -508,3 +510,78 @@ static void its_send_invall(struct its_node *its, struct its_collection *col)

its_send_single_command(its, its_build_invall_cmd, &desc);
}
+
+/*
+ * irqchip functions - assumes MSI, mostly.
+ */
+
+static inline u32 its_get_event_id(struct irq_data *d)
+{
+ struct its_device *its_dev = irq_data_get_irq_chip_data(d);
+ return d->hwirq - its_dev->lpi_base;
+}
+
+static void lpi_set_config(struct irq_data *d, bool enable)
+{
+ struct its_device *its_dev = irq_data_get_irq_chip_data(d);
+ irq_hw_number_t hwirq = d->hwirq;
+ u32 id = its_get_event_id(d);
+ u8 *cfg = page_address(gic_rdists->prop_page) + hwirq - 8192;
+
+ if (enable)
+ *cfg |= LPI_PROP_ENABLED;
+ else
+ *cfg &= ~LPI_PROP_ENABLED;
+
+ /*
+ * Make the above write visible to the redistributors.
+ * And yes, we're flushing exactly: One. Single. Byte.
+ * Humpf...
+ */
+ if (gic_rdists->flags & RDIST_FLAGS_PROPBASE_NEEDS_FLUSHING)
+ __flush_dcache_area(cfg, sizeof(*cfg));
+ else
+ dsb(ishst);
+ its_send_inv(its_dev, id);
+}
+
+static void its_mask_irq(struct irq_data *d)
+{
+ lpi_set_config(d, false);
+}
+
+static void its_unmask_irq(struct irq_data *d)
+{
+ lpi_set_config(d, true);
+}
+
+static void its_eoi_irq(struct irq_data *d)
+{
+ gic_write_eoir(d->hwirq);
+}
+
+static int its_set_affinity(struct irq_data *d, const struct cpumask *mask_val,
+ bool force)
+{
+ unsigned int cpu = cpumask_any_and(mask_val, cpu_online_mask);
+ struct its_device *its_dev = irq_data_get_irq_chip_data(d);
+ struct its_collection *target_col;
+ u32 id = its_get_event_id(d);
+
+ if (cpu >= nr_cpu_ids)
+ return -EINVAL;
+
+ target_col = &its_dev->its->collections[cpu];
+ its_send_movi(its_dev, target_col, id);
+ its_dev->collection = target_col;
+
+ return IRQ_SET_MASK_OK;
+}
+
+static struct irq_chip its_irq_chip = {
+ .name = "ITS",
+ .irq_mask = its_mask_irq,
+ .irq_unmask = its_unmask_irq,
+ .irq_eoi = its_eoi_irq,
+ .irq_set_affinity = its_set_affinity,
+};
--
2.0.4

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