diff options
| -rw-r--r-- | drivers/irqchip/irq-gic-v3-its.c | 56 | ||||
| -rw-r--r-- | include/linux/irqchip/arm-gic-v4.h | 5 |
2 files changed, 53 insertions, 8 deletions
diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c index da883a691028..1af713990123 100644 --- a/drivers/irqchip/irq-gic-v3-its.c +++ b/drivers/irqchip/irq-gic-v3-its.c @@ -239,15 +239,41 @@ static struct its_vlpi_map *get_vlpi_map(struct irq_data *d) return NULL; } -static int irq_to_cpuid(struct irq_data *d) +static int vpe_to_cpuid_lock(struct its_vpe *vpe, unsigned long *flags) +{ + raw_spin_lock_irqsave(&vpe->vpe_lock, *flags); + return vpe->col_idx; +} + +static void vpe_to_cpuid_unlock(struct its_vpe *vpe, unsigned long flags) +{ + raw_spin_unlock_irqrestore(&vpe->vpe_lock, flags); +} + +static int irq_to_cpuid_lock(struct irq_data *d, unsigned long *flags) { - struct its_device *its_dev = irq_data_get_irq_chip_data(d); struct its_vlpi_map *map = get_vlpi_map(d); + int cpu; - if (map) - return map->vpe->col_idx; + if (map) { + cpu = vpe_to_cpuid_lock(map->vpe, flags); + } else { + /* Physical LPIs are already locked via the irq_desc lock */ + struct its_device *its_dev = irq_data_get_irq_chip_data(d); + cpu = its_dev->event_map.col_map[its_get_event_id(d)]; + /* Keep GCC quiet... */ + *flags = 0; + } - return its_dev->event_map.col_map[its_get_event_id(d)]; + return cpu; +} + +static void irq_to_cpuid_unlock(struct irq_data *d, unsigned long flags) +{ + struct its_vlpi_map *map = get_vlpi_map(d); + + if (map) + vpe_to_cpuid_unlock(map->vpe, flags); } static struct its_collection *valid_col(struct its_collection *col) @@ -1329,7 +1355,9 @@ static void direct_lpi_inv(struct irq_data *d) { struct its_vlpi_map *map = get_vlpi_map(d); void __iomem *rdbase; + unsigned long flags; u64 val; + int cpu; if (map) { struct its_device *its_dev = irq_data_get_irq_chip_data(d); @@ -1344,10 +1372,12 @@ static void direct_lpi_inv(struct irq_data *d) } /* Target the redistributor this LPI is currently routed to */ - rdbase = per_cpu_ptr(gic_rdists->rdist, irq_to_cpuid(d))->rd_base; + cpu = irq_to_cpuid_lock(d, &flags); + rdbase = per_cpu_ptr(gic_rdists->rdist, cpu)->rd_base; gic_write_lpir(val, rdbase + GICR_INVLPIR); wait_for_syncr(rdbase); + irq_to_cpuid_unlock(d, flags); } static void lpi_update_config(struct irq_data *d, u8 clr, u8 set) @@ -3486,17 +3516,25 @@ static int its_vpe_set_affinity(struct irq_data *d, { struct its_vpe *vpe = irq_data_get_irq_chip_data(d); int from, cpu = cpumask_first(mask_val); + unsigned long flags; /* * Changing affinity is mega expensive, so let's be as lazy as * we can and only do it if we really have to. Also, if mapped * into the proxy device, we need to move the doorbell * interrupt to its new location. + * + * Another thing is that changing the affinity of a vPE affects + * *other interrupts* such as all the vLPIs that are routed to + * this vPE. This means that the irq_desc lock is not enough to + * protect us, and that we must ensure nobody samples vpe->col_idx + * during the update, hence the lock below which must also be + * taken on any vLPI handling path that evaluates vpe->col_idx. */ - if (vpe->col_idx == cpu) + from = vpe_to_cpuid_lock(vpe, &flags); + if (from == cpu) goto out; - from = vpe->col_idx; vpe->col_idx = cpu; /* @@ -3512,6 +3550,7 @@ static int its_vpe_set_affinity(struct irq_data *d, out: irq_data_update_effective_affinity(d, cpumask_of(cpu)); + vpe_to_cpuid_unlock(vpe, flags); return IRQ_SET_MASK_OK_DONE; } @@ -3855,6 +3894,7 @@ static int its_vpe_init(struct its_vpe *vpe) return -ENOMEM; } + raw_spin_lock_init(&vpe->vpe_lock); vpe->vpe_id = vpe_id; vpe->vpt_page = vpt_page; if (gic_rdists->has_rvpeid) diff --git a/include/linux/irqchip/arm-gic-v4.h b/include/linux/irqchip/arm-gic-v4.h index d9c34968467a..439963f4c66a 100644 --- a/include/linux/irqchip/arm-gic-v4.h +++ b/include/linux/irqchip/arm-gic-v4.h @@ -54,6 +54,11 @@ struct its_vpe { }; /* + * Ensures mutual exclusion between affinity setting of the + * vPE and vLPI operations using vpe->col_idx. + */ + raw_spinlock_t vpe_lock; + /* * This collection ID is used to indirect the target * redistributor for this VPE. The ID itself isn't involved in * programming of the ITS. |