Commit ed0e4aa9 authored by Marc Zyngier's avatar Marc Zyngier
Browse files

irqchip/gic-v3-its: Synchronise INT/CLEAR commands targetting a VLPI using VSYNC 



We have so far always injected/cleared VLPIs using either
INT+SYNC or CLEAR+SYNC sequences, 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 {INT,CLEAR}+VSYNC for forwarded LPIs, ensuring
that the ITS synchronises against the virtual pending table.

Reported-by: default avatarZenghui Yu <yuzenghui@huawei.com>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20191108165805.3071-10-maz@kernel.org
parent 28614696

drivers/irqchip/irq-gic-v3-its.c

+75 −4
Original line number Diff line number Diff line
@@ -721,6 +721,42 @@ static struct its_vpe *its_build_vinv_cmd(struct its_node *its, 
	return valid_vpe(its, map->vpe);

}



static struct its_vpe *its_build_vint_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_int_cmd.dev,

				    desc->its_int_cmd.event_id);



	its_encode_cmd(cmd, GITS_CMD_INT);

	its_encode_devid(cmd, desc->its_int_cmd.dev->device_id);

	its_encode_event_id(cmd, desc->its_int_cmd.event_id);



	its_fixup_cmd(cmd);



	return valid_vpe(its, map->vpe);

}



static struct its_vpe *its_build_vclear_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_clear_cmd.dev,

				    desc->its_clear_cmd.event_id);



	its_encode_cmd(cmd, GITS_CMD_CLEAR);

	its_encode_devid(cmd, desc->its_clear_cmd.dev->device_id);

	its_encode_event_id(cmd, desc->its_clear_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)

{
@@ -1101,6 +1137,34 @@ static void its_send_vinv(struct its_device *dev, u32 event_id) 
	its_send_single_vcommand(dev->its, its_build_vinv_cmd, &desc);

}



static void its_send_vint(struct its_device *dev, u32 event_id)

{

	struct its_cmd_desc desc;



	/*

	 * There is no real VINT command. This is just a normal INT,

	 * with a VSYNC instead of a SYNC.

	 */

	desc.its_int_cmd.dev = dev;

	desc.its_int_cmd.event_id = event_id;



	its_send_single_vcommand(dev->its, its_build_vint_cmd, &desc);

}



static void its_send_vclear(struct its_device *dev, u32 event_id)

{

	struct its_cmd_desc desc;



	/*

	 * There is no real VCLEAR command. This is just a normal CLEAR,

	 * with a VSYNC instead of a SYNC.

	 */

	desc.its_clear_cmd.dev = dev;

	desc.its_clear_cmd.event_id = event_id;



	its_send_single_vcommand(dev->its, its_build_vclear_cmd, &desc);

}



/*

 * irqchip functions - assumes MSI, mostly.

 */
@@ -1294,10 +1358,17 @@ static int its_irq_set_irqchip_state(struct irq_data *d, 
	if (which != IRQCHIP_STATE_PENDING)

		return -EINVAL;



	if (irqd_is_forwarded_to_vcpu(d)) {

		if (state)

			its_send_vint(its_dev, event);

		else

			its_send_vclear(its_dev, event);

	} else {

		if (state)

			its_send_int(its_dev, event);

		else

			its_send_clear(its_dev, event);

	}



	return 0;

}

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