[PATCH v3 01/32] irqchip/gic-v3: Detect GICv4.1 supporting RVPEID

Marc Zyngier
2019-12-24T11:11:31Z

GICv4.1 supports the RVPEID ("Residency per vPE ID"), which allows for
a much efficient way of making virtual CPUs resident (to allow direct
injection of interrupts).

The functionnality needs to be discovered on each and every redistributor
in the system, and disabled if the settings are inconsistent.

Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
drivers/irqchip/irq-gic-v3.c | 21 ++++++++++++++++++---
include/linux/irqchip/arm-gic-v3.h | 2 ++
2 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
index d6218012097b..ffcb018395ed 100644
--- a/drivers/irqchip/irq-gic-v3.c
+++ b/drivers/irqchip/irq-gic-v3.c
@@ -858,8 +858,21 @@ static int __gic_update_rdist_properties(struct redist_region *region,
void __iomem *ptr)
{
u64 typer = gic_read_typer(ptr + GICR_TYPER);
+
gic_data.rdists.has_vlpis &= !!(typer & GICR_TYPER_VLPIS);
- gic_data.rdists.has_direct_lpi &= !!(typer & GICR_TYPER_DirectLPIS);
+
+ /* RVPEID implies some form of DirectLPI, no matter what the doc says... :-/ */
+ gic_data.rdists.has_rvpeid &= !!(typer & GICR_TYPER_RVPEID);
+ gic_data.rdists.has_direct_lpi &= (!!(typer & GICR_TYPER_DirectLPIS) |
+ gic_data.rdists.has_rvpeid);
+
+ /* Detect non-sensical configurations */
+ if (WARN_ON_ONCE(gic_data.rdists.has_rvpeid && !gic_data.rdists.has_vlpis)) {
+ gic_data.rdists.has_direct_lpi = false;
+ gic_data.rdists.has_vlpis = false;
+ gic_data.rdists.has_rvpeid = false;
+ }
+
gic_data.ppi_nr = min(GICR_TYPER_NR_PPIS(typer), gic_data.ppi_nr);

return 1;
@@ -872,9 +885,10 @@ static void gic_update_rdist_properties(void)
if (WARN_ON(gic_data.ppi_nr == UINT_MAX))
gic_data.ppi_nr = 0;
pr_info("%d PPIs implemented\n", gic_data.ppi_nr);
- pr_info("%sVLPI support, %sdirect LPI support\n",
+ pr_info("%sVLPI support, %sdirect LPI support, %sRVPEID support\n",
!gic_data.rdists.has_vlpis ? "no " : "",
- !gic_data.rdists.has_direct_lpi ? "no " : "");
+ !gic_data.rdists.has_direct_lpi ? "no " : "",
+ !gic_data.rdists.has_rvpeid ? "no " : "");
}

/* Check whether it's single security state view */
@@ -1566,6 +1580,7 @@ static int __init gic_init_bases(void __iomem *dist_base,
&gic_data);
irq_domain_update_bus_token(gic_data.domain, DOMAIN_BUS_WIRED);
gic_data.rdists.rdist = alloc_percpu(typeof(*gic_data.rdists.rdist));
+ gic_data.rdists.has_rvpeid = true;
gic_data.rdists.has_vlpis = true;
gic_data.rdists.has_direct_lpi = true;

diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
index de991d6633a5..9a5f85d30701 100644
--- a/include/linux/irqchip/arm-gic-v3.h
+++ b/include/linux/irqchip/arm-gic-v3.h
@@ -234,6 +234,7 @@
#define GICR_TYPER_VLPIS (1U << 1)
#define GICR_TYPER_DirectLPIS (1U << 3)
#define GICR_TYPER_LAST (1U << 4)
+#define GICR_TYPER_RVPEID (1U << 7)

#define GIC_V3_REDIST_SIZE 0x20000

@@ -615,6 +616,7 @@ struct rdists {
u64 flags;
u32 gicd_typer;
bool has_vlpis;
+ bool has_rvpeid;
bool has_direct_lpi;
};

--
2.20.1