[PATCH] arm64: gic-v3: fix unexpected overwrite of spi/ppi/sgi prio

[PATCH] arm64: gic-v3: fix unexpected overwrite of spi/ppi/sgi prio

[Wei Li]

The priority config will be restored to the default value in the
notifiers of gic suspend. While the arm64 nmi-like interrupt has been
implemented by using priority since commit bc3c03ccb464 ("arm64: Enable
the support of pseudo-NMIs"), we need to do the save and restore exactly.

Signed-off-by: Wei Li <liwei391@huawei.com>
---
 drivers/irqchip/irq-gic.c | 22 +++++++++++++++++++---
 1 file changed, 19 insertions(+), 3 deletions(-)

diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
index fd3110c171ba..5928c4338b28 100644
--- a/drivers/irqchip/irq-gic.c
+++ b/drivers/irqchip/irq-gic.c
@@ -79,10 +79,12 @@ struct gic_chip_data {
 	u32 saved_spi_enable[DIV_ROUND_UP(1020, 32)];
 	u32 saved_spi_active[DIV_ROUND_UP(1020, 32)];
 	u32 saved_spi_conf[DIV_ROUND_UP(1020, 16)];
+	u32 saved_spi_prio[DIV_ROUND_UP(1020, 4)];
 	u32 saved_spi_target[DIV_ROUND_UP(1020, 4)];
 	u32 __percpu *saved_ppi_enable;
 	u32 __percpu *saved_ppi_active;
 	u32 __percpu *saved_ppi_conf;
+	u32 __percpu *saved_ppi_prio;
 #endif
 	struct irq_domain *domain;
 	unsigned int gic_irqs;
@@ -599,6 +601,10 @@ void gic_dist_save(struct gic_chip_data *gic)
 	for (i = 0; i < DIV_ROUND_UP(gic_irqs, 32); i++)
 		gic->saved_spi_active[i] =
 			readl_relaxed(dist_base + GIC_DIST_ACTIVE_SET + i * 4);
+
+	for (i = 0; i < DIV_ROUND_UP(gic_irqs, 4); i++)
+		gic->saved_spi_prio[i] =
+			readl_relaxed(dist_base + GIC_DIST_PRI + i * 4);
 }
 
 /*
@@ -630,7 +636,7 @@ void gic_dist_restore(struct gic_chip_data *gic)
 			dist_base + GIC_DIST_CONFIG + i * 4);
 
 	for (i = 0; i < DIV_ROUND_UP(gic_irqs, 4); i++)
-		writel_relaxed(GICD_INT_DEF_PRI_X4,
+		writel_relaxed(gic->saved_spi_prio[i],
 			dist_base + GIC_DIST_PRI + i * 4);
 
 	for (i = 0; i < DIV_ROUND_UP(gic_irqs, 4); i++)
@@ -682,6 +688,9 @@ void gic_cpu_save(struct gic_chip_data *gic)
 	for (i = 0; i < DIV_ROUND_UP(32, 16); i++)
 		ptr[i] = readl_relaxed(dist_base + GIC_DIST_CONFIG + i * 4);
 
+	ptr = raw_cpu_ptr(gic->saved_ppi_prio);
+	for (i = 0; i < DIV_ROUND_UP(32, 4); i++)
+		ptr[i] = readl_relaxed(dist_base + GIC_DIST_PRI + i * 4);
 }
 
 void gic_cpu_restore(struct gic_chip_data *gic)
@@ -718,9 +727,9 @@ void gic_cpu_restore(struct gic_chip_data *gic)
 	for (i = 0; i < DIV_ROUND_UP(32, 16); i++)
 		writel_relaxed(ptr[i], dist_base + GIC_DIST_CONFIG + i * 4);
 
+	ptr = raw_cpu_ptr(gic->saved_ppi_prio);
 	for (i = 0; i < DIV_ROUND_UP(32, 4); i++)
-		writel_relaxed(GICD_INT_DEF_PRI_X4,
-					dist_base + GIC_DIST_PRI + i * 4);
+		writel_relaxed(ptr[i], dist_base + GIC_DIST_PRI + i * 4);
 
 	writel_relaxed(GICC_INT_PRI_THRESHOLD, cpu_base + GIC_CPU_PRIMASK);
 	gic_cpu_if_up(gic);
@@ -778,11 +787,18 @@ static int gic_pm_init(struct gic_chip_data *gic)
 	if (WARN_ON(!gic->saved_ppi_conf))
 		goto free_ppi_active;
 
+	gic->saved_ppi_prio = __alloc_percpu(DIV_ROUND_UP(32, 4) * 4,
+		sizeof(u32));
+	if (WARN_ON(!gic->saved_ppi_prio))
+		goto free_ppi_prio;
+
 	if (gic == &gic_data[0])
 		cpu_pm_register_notifier(&gic_notifier_block);
 
 	return 0;
 
+free_ppi_prio:
+	free_percpu(gic->saved_ppi_conf);
 free_ppi_active:
 	free_percpu(gic->saved_ppi_active);
 free_ppi_enable:
-- 
2.17.1

Re: [PATCH] arm64: gic-v3: fix unexpected overwrite of spi/ppi/sgi prio

[Marc Zyngier]

On 26/03/2019 08:16, Wei Li wrote:
> The priority config will be restored to the default value in the
> notifiers of gic suspend. While the arm64 nmi-like interrupt has been
> implemented by using priority since commit bc3c03ccb464 ("arm64: Enable
> the support of pseudo-NMIs"), we need to do the save and restore exactly.
> 
> Signed-off-by: Wei Li <liwei391@huawei.com>
> ---
>  drivers/irqchip/irq-gic.c | 22 +++++++++++++++++++---
>  1 file changed, 19 insertions(+), 3 deletions(-)

You're complaining about an alleged bug in the GICv3 driver (which is
always possible), and yet you're submitting a change to the GICv{1,2}
driver, for which we don't support variable priorities.

How does this fix anything? How have you tested this patch? What is the
actual problem you're trying to paper over?

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...