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irqchip/gic-v4.1: Don't use the VPE proxy if RVPEID is set

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The infamous VPE proxy device isn't used with GICv4.1 because:
- we can invalidate any LPI from the DirectLPI MMIO interface
- the ITS and redistributors understand the life cycle of
  the doorbell, so we don't need to enable/disable it all
  the time

So let's escape early from the proxy related functions.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>
Link: https://lore.kernel.org/r/20191224111055.11836-8-maz@kernel.org
This commit is contained in:
Marc Zyngier 2019-12-24 11:10:30 +00:00
parent 64edfaa9a2
commit 0684c70465
1 changed files with 24 additions and 1 deletions
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25
drivers/irqchip/irq-gic-v3-its.c
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@ -3212,7 +3212,7 @@ static const struct irq_domain_ops its_domain_ops = {
/*
* This is insane.
*
* If a GICv4 doesn't implement Direct LPIs (which is extremely
* If a GICv4.0 doesn't implement Direct LPIs (which is extremely
* likely), the only way to perform an invalidate is to use a fake
* device to issue an INV command, implying that the LPI has first
* been mapped to some event on that device. Since this is not exactly
@ -3220,9 +3220,20 @@ static const struct irq_domain_ops its_domain_ops = {
* only issue an UNMAP if we're short on available slots.
*
* Broken by design(tm).
*
* GICv4.1, on the other hand, mandates that we're able to invalidate
* by writing to a MMIO register. It doesn't implement the whole of
* DirectLPI, but that's good enough. And most of the time, we don't
* even have to invalidate anything, as the redistributor can be told
* whether to generate a doorbell or not (we thus leave it enabled,
* always).
*/
static void its_vpe_db_proxy_unmap_locked(struct its_vpe *vpe)
{
/* GICv4.1 doesn't use a proxy, so nothing to do here */
if (gic_rdists->has_rvpeid)
return;
/* Already unmapped? */
if (vpe->vpe_proxy_event == -1)
return;
@ -3245,6 +3256,10 @@ static void its_vpe_db_proxy_unmap_locked(struct its_vpe *vpe)
static void its_vpe_db_proxy_unmap(struct its_vpe *vpe)
{
/* GICv4.1 doesn't use a proxy, so nothing to do here */
if (gic_rdists->has_rvpeid)
return;
if (!gic_rdists->has_direct_lpi) {
unsigned long flags;
@ -3256,6 +3271,10 @@ static void its_vpe_db_proxy_unmap(struct its_vpe *vpe)
static void its_vpe_db_proxy_map_locked(struct its_vpe *vpe)
{
/* GICv4.1 doesn't use a proxy, so nothing to do here */
if (gic_rdists->has_rvpeid)
return;
/* Already mapped? */
if (vpe->vpe_proxy_event != -1)
return;
@ -3278,6 +3297,10 @@ static void its_vpe_db_proxy_move(struct its_vpe *vpe, int from, int to)
unsigned long flags;
struct its_collection *target_col;
/* GICv4.1 doesn't use a proxy, so nothing to do here */
if (gic_rdists->has_rvpeid)
return;
if (gic_rdists->has_direct_lpi) {
void __iomem *rdbase;