[PATCH v2 03/36] irqchip/gic-v3-its: Allow LPI invalidation via the DirectLPI interface

Marc Zyngier
2019-10-27T14:43:20Z

We currently don't make much use of the DirectLPI feature, and it would
be beneficial to do this more, if only because it becomes a mandatory
feature for GICv4.1.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
drivers/irqchip/irq-gic-v3-its.c | 40 +++++++++++++++++++++++++-------
1 file changed, 32 insertions(+), 8 deletions(-)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 58cb233cf138..3e33cdc08200 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -175,6 +175,12 @@ static DEFINE_IDA(its_vpeid_ida);
#define gic_data_rdist_rd_base() (gic_data_rdist()->rd_base)
#define gic_data_rdist_vlpi_base() (gic_data_rdist_rd_base() + SZ_128K)

+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->event_map.lpi_base;
+}
+
static struct its_collection *dev_event_to_col(struct its_device *its_dev,
u32 event)
{
@@ -183,6 +189,13 @@ static struct its_collection *dev_event_to_col(struct its_device *its_dev,
return its->collections + its_dev->event_map.col_map[event];
}

+static struct its_collection *irq_to_col(struct irq_data *d)
+{
+ struct its_device *its_dev = irq_data_get_irq_chip_data(d);
+
+ return dev_event_to_col(its_dev, its_get_event_id(d));
+}
+
static struct its_collection *valid_col(struct its_collection *col)
{
if (WARN_ON_ONCE(col->target_address & GENMASK_ULL(15, 0)))
@@ -1031,12 +1044,6 @@ static void its_send_vinvall(struct its_node *its, struct its_vpe *vpe)
* 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->event_map.lpi_base;
-}
-
static void lpi_write_config(struct irq_data *d, u8 clr, u8 set)
{
irq_hw_number_t hwirq;
@@ -1081,12 +1088,28 @@ static void wait_for_syncr(void __iomem *rdbase)
cpu_relax();
}

+static void direct_lpi_inv(struct irq_data *d)
+{
+ struct its_collection *col;
+ void __iomem *rdbase;
+
+ /* Target the redistributor this LPI is currently routed to */
+ col = irq_to_col(d);
+ rdbase = per_cpu_ptr(gic_rdists->rdist, col->col_id)->rd_base;
+ gic_write_lpir(d->hwirq, rdbase + GICR_INVLPIR);
+
+ wait_for_syncr(rdbase);
+}
+
static void lpi_update_config(struct irq_data *d, u8 clr, u8 set)
{
struct its_device *its_dev = irq_data_get_irq_chip_data(d);

lpi_write_config(d, clr, set);
- its_send_inv(its_dev, its_get_event_id(d));
+ if (gic_rdists->has_direct_lpi && !irqd_is_forwarded_to_vcpu(d))
+ direct_lpi_inv(d);
+ else
+ its_send_inv(its_dev, its_get_event_id(d));
}

static void its_vlpi_set_doorbell(struct irq_data *d, bool enable)
@@ -2917,8 +2940,9 @@ static void its_vpe_send_inv(struct irq_data *d)
if (gic_rdists->has_direct_lpi) {
void __iomem *rdbase;

+ /* Target the redistributor this VPE is currently known on */
rdbase = per_cpu_ptr(gic_rdists->rdist, vpe->col_idx)->rd_base;
- gic_write_lpir(vpe->vpe_db_lpi, rdbase + GICR_INVLPIR);
+ gic_write_lpir(d->parent_data->hwirq, rdbase + GICR_INVLPIR);
wait_for_syncr(rdbase);
} else {
its_vpe_send_cmd(vpe, its_send_inv);