Re: [PATCH v2 05/12] irqchip/gic: Prepare for more than 16 PPIs

From: Julien
Date: Thu Aug 22 2019 - 12:11:31 EST

Hi Marc,

On 06/08/19 11:01, Marc Zyngier wrote:
GICv3.1 allows up to 80 PPIs (16 legaci PPIs and 64 Extended PPIs),
meaning we can't just leave the old 16 hardcoded everywhere.

We also need to add the infrastructure to discover the number of PPIs
on a per redistributor basis, although we still pretend there is only
16 of them for now.

No functional change.

Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
---
drivers/irqchip/irq-gic-common.c | 19 ++++++++++++-------
drivers/irqchip/irq-gic-common.h | 2 +-
drivers/irqchip/irq-gic-v3.c | 22 +++++++++++++++-------
drivers/irqchip/irq-gic.c | 2 +-
drivers/irqchip/irq-hip04.c | 2 +-
5 files changed, 30 insertions(+), 17 deletions(-)

diff --git a/drivers/irqchip/irq-gic-common.c b/drivers/irqchip/irq-gic-common.c
index 6900b6f0921c..14110db01c05 100644
--- a/drivers/irqchip/irq-gic-common.c
+++ b/drivers/irqchip/irq-gic-common.c
@@ -128,26 +128,31 @@ void gic_dist_config(void __iomem *base, int gic_irqs,
sync_access();
}
-void gic_cpu_config(void __iomem *base, void (*sync_access)(void))
+void gic_cpu_config(void __iomem *base, int nr, void (*sync_access)(void))
{
int i;
/*
* Deal with the banked PPI and SGI interrupts - disable all
- * PPI interrupts, ensure all SGI interrupts are enabled.
- * Make sure everything is deactivated.
+ * private interrupts. Make sure everything is deactivated.
*/
- writel_relaxed(GICD_INT_EN_CLR_X32, base + GIC_DIST_ACTIVE_CLEAR);
- writel_relaxed(GICD_INT_EN_CLR_PPI, base + GIC_DIST_ENABLE_CLEAR);
- writel_relaxed(GICD_INT_EN_SET_SGI, base + GIC_DIST_ENABLE_SET);
+ for (i = 0; i < nr; i += 32) {

You added "nr" as argument but if "nr" isn't a multiple of 32 weird things might happen, no?

It would be worth specifying that somewhere, and checking it with a WARN().

Maybe it might be worth reducing the granularity to manipulating 16 irqs since there are 16 SGI + 16 PPI + 64 EPPI, but that might not be very useful right now.

Cheers,

Julien

+ writel_relaxed(GICD_INT_EN_CLR_X32,
+ base + GIC_DIST_ACTIVE_CLEAR + i / 8);
+ writel_relaxed(GICD_INT_EN_CLR_X32,
+ base + GIC_DIST_ENABLE_CLEAR + i / 8);
+ }
/*
* Set priority on PPI and SGI interrupts
*/
- for (i = 0; i < 32; i += 4)
+ for (i = 0; i < nr; i += 4)
writel_relaxed(GICD_INT_DEF_PRI_X4,
base + GIC_DIST_PRI + i * 4 / 4);
+ /* Ensure all SGI interrupts are now enabled */
+ writel_relaxed(GICD_INT_EN_SET_SGI, base + GIC_DIST_ENABLE_SET);
+
if (sync_access)
sync_access();
}
diff --git a/drivers/irqchip/irq-gic-common.h b/drivers/irqchip/irq-gic-common.h
index 5a46b6b57750..ccba8b0fe0f5 100644
--- a/drivers/irqchip/irq-gic-common.h
+++ b/drivers/irqchip/irq-gic-common.h
@@ -22,7 +22,7 @@ int gic_configure_irq(unsigned int irq, unsigned int type,
void __iomem *base, void (*sync_access)(void));
void gic_dist_config(void __iomem *base, int gic_irqs,
void (*sync_access)(void));
-void gic_cpu_config(void __iomem *base, void (*sync_access)(void));
+void gic_cpu_config(void __iomem *base, int nr, void (*sync_access)(void));
void gic_enable_quirks(u32 iidr, const struct gic_quirk *quirks,
void *data);
void gic_enable_of_quirks(const struct device_node *np,
diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
index 1ca4dde32034..e03fb6d7c2ce 100644
--- a/drivers/irqchip/irq-gic-v3.c
+++ b/drivers/irqchip/irq-gic-v3.c
@@ -51,6 +51,7 @@ struct gic_chip_data {
u32 nr_redist_regions;
u64 flags;
bool has_rss;
+ unsigned int ppi_nr;
struct partition_desc *ppi_descs[16];
};
@@ -812,19 +813,24 @@ static int gic_populate_rdist(void)
return -ENODEV;
}
-static int __gic_update_vlpi_properties(struct redist_region *region,
- void __iomem *ptr)
+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);
+ gic_data.ppi_nr = 16;
return 1;
}
-static void gic_update_vlpi_properties(void)
+static void gic_update_rdist_properties(void)
{
- gic_iterate_rdists(__gic_update_vlpi_properties);
+ gic_data.ppi_nr = UINT_MAX;
+ gic_iterate_rdists(__gic_update_rdist_properties);
+ 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",
!gic_data.rdists.has_vlpis ? "no " : "",
!gic_data.rdists.has_direct_lpi ? "no " : "");
@@ -968,6 +974,7 @@ static int gic_dist_supports_lpis(void)
static void gic_cpu_init(void)
{
void __iomem *rbase;
+ int i;
/* Register ourselves with the rest of the world */
if (gic_populate_rdist())
@@ -978,9 +985,10 @@ static void gic_cpu_init(void)
rbase = gic_data_rdist_sgi_base();
/* Configure SGIs/PPIs as non-secure Group-1 */
- writel_relaxed(~0, rbase + GICR_IGROUPR0);
+ for (i = 0; i < gic_data.ppi_nr + 16; i += 32)
+ writel_relaxed(~0, rbase + GICR_IGROUPR0 + i / 8);
- gic_cpu_config(rbase, gic_redist_wait_for_rwp);
+ gic_cpu_config(rbase, gic_data.ppi_nr + 16, gic_redist_wait_for_rwp);
/* initialise system registers */
gic_cpu_sys_reg_init();
@@ -1449,7 +1457,7 @@ static int __init gic_init_bases(void __iomem *dist_base,
set_handle_irq(gic_handle_irq);
- gic_update_vlpi_properties();
+ gic_update_rdist_properties();
gic_smp_init();
gic_dist_init();
diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
index ab48760acabb..25c1ae69db30 100644
--- a/drivers/irqchip/irq-gic.c
+++ b/drivers/irqchip/irq-gic.c
@@ -543,7 +543,7 @@ static int gic_cpu_init(struct gic_chip_data *gic)
gic_cpu_map[i] &= ~cpu_mask;
}
- gic_cpu_config(dist_base, NULL);
+ gic_cpu_config(dist_base, 32, NULL);
writel_relaxed(GICC_INT_PRI_THRESHOLD, base + GIC_CPU_PRIMASK);
gic_cpu_if_up(gic);
diff --git a/drivers/irqchip/irq-hip04.c b/drivers/irqchip/irq-hip04.c
index 1626131834a6..130caa1c9d93 100644
--- a/drivers/irqchip/irq-hip04.c
+++ b/drivers/irqchip/irq-hip04.c
@@ -273,7 +273,7 @@ static void hip04_irq_cpu_init(struct hip04_irq_data *intc)
if (i != cpu)
hip04_cpu_map[i] &= ~cpu_mask;
- gic_cpu_config(dist_base, NULL);
+ gic_cpu_config(dist_base, 32, NULL);
writel_relaxed(0xf0, base + GIC_CPU_PRIMASK);
writel_relaxed(1, base + GIC_CPU_CTRL);


--
Julien Thierry