[PATCH 08/11] irqchip/gic-v3-its: Synchronise INV command targetting a VLPI using VSYNC

Marc Zyngier
2019-11-05T16:23:35Z

We have so far always invalidated VLPIs usinc an INV+SYNC
sequence, but that's pretty wrong for two reasons:

- SYNC only synchronises physical LPIs
- The collection ID that for the associated LPI doesn't match
the redistributor the vPE is associated with

Instead, send an INV+VSYNC for forwarded LPIs, ensuring that
the ITS can properly synchronise the invalidation of VLPIs.

Fixes: 015ec0386ab6 ("irqchip/gic-v3-its: Add VLPI configuration handling")
Reported-by: Zenghui Yu <yuzenghui@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
drivers/irqchip/irq-gic-v3-its.c | 36 +++++++++++++++++++++++++++++++-
1 file changed, 35 insertions(+), 1 deletion(-)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index c8c280f803a5..d4b9f12e2e53 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -700,6 +700,24 @@ static struct its_vpe *its_build_vmovp_cmd(struct its_node *its,
return valid_vpe(its, desc->its_vmovp_cmd.vpe);
}

+static struct its_vpe *its_build_vinv_cmd(struct its_node *its,
+ struct its_cmd_block *cmd,
+ struct its_cmd_desc *desc)
+{
+ struct its_vlpi_map *map;
+
+ map = dev_event_to_vlpi_map(desc->its_inv_cmd.dev,
+ desc->its_inv_cmd.event_id);
+
+ its_encode_cmd(cmd, GITS_CMD_INV);
+ its_encode_devid(cmd, desc->its_inv_cmd.dev->device_id);
+ its_encode_event_id(cmd, desc->its_inv_cmd.event_id);
+
+ its_fixup_cmd(cmd);
+
+ return valid_vpe(its, map->vpe);
+}
+
static u64 its_cmd_ptr_to_offset(struct its_node *its,
struct its_cmd_block *ptr)
{
@@ -1066,6 +1084,20 @@ static void its_send_vinvall(struct its_node *its, struct its_vpe *vpe)
its_send_single_vcommand(its, its_build_vinvall_cmd, &desc);
}

+static void its_send_vinv(struct its_device *dev, u32 event_id)
+{
+ struct its_cmd_desc desc;
+
+ /*
+ * There is no real VINV command. This is just a normal INV,
+ * with a VSYNC instead of a SYNC.
+ */
+ desc.its_inv_cmd.dev = dev;
+ desc.its_inv_cmd.event_id = event_id;
+
+ its_send_single_vcommand(dev->its, its_build_vinv_cmd, &desc);
+}
+
/*
* irqchip functions - assumes MSI, mostly.
*/
@@ -1140,8 +1172,10 @@ static void lpi_update_config(struct irq_data *d, u8 clr, u8 set)
lpi_write_config(d, clr, set);
if (gic_rdists->has_direct_lpi && !irqd_is_forwarded_to_vcpu(d))
direct_lpi_inv(d);
- else
+ else if (!irqd_is_forwarded_to_vcpu(d))
its_send_inv(its_dev, its_get_event_id(d));
+ else
+ its_send_vinv(its_dev, its_get_event_id(d));
}

static void its_vlpi_set_doorbell(struct irq_data *d, bool enable)
--
2.20.1