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irqchip/gic-v4.1: Ensure mutual exclusion betwen invalidations on the same RD

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The GICv4.1 spec says that it is CONTRAINED UNPREDICTABLE to write to
any of the GICR_INV{LPI,ALL}R registers if GICR_SYNCR.Busy == 1.

To deal with it, we must ensure that only a single invalidation can
happen at a time for a given redistributor. Add a per-RD lock to that
effect and take it around the invalidation/syncr-read to deal with this.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Link: https://lore.kernel.org/r/20200304203330.4967-6-maz@kernel.org
This commit is contained in:
Marc Zyngier 2020-03-04 20:33:12 +00:00
parent b978c25f6e
commit 9058a4e980
3 changed files with 8 additions and 0 deletions
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6
drivers/irqchip/irq-gic-v3-its.c
View file

@ -1373,10 +1373,12 @@ static void direct_lpi_inv(struct irq_data *d)
/* Target the redistributor this LPI is currently routed to */
cpu = irq_to_cpuid_lock(d, &flags);
raw_spin_lock(&gic_data_rdist_cpu(cpu)->rd_lock);
rdbase = per_cpu_ptr(gic_rdists->rdist, cpu)->rd_base;
gic_write_lpir(val, rdbase + GICR_INVLPIR);
wait_for_syncr(rdbase);
raw_spin_unlock(&gic_data_rdist_cpu(cpu)->rd_lock);
irq_to_cpuid_unlock(d, flags);
}
@ -3662,9 +3664,11 @@ static void its_vpe_send_inv(struct irq_data *d)
void __iomem *rdbase;
/* Target the redistributor this VPE is currently known on */
raw_spin_lock(&gic_data_rdist_cpu(vpe->col_idx)->rd_lock);
rdbase = per_cpu_ptr(gic_rdists->rdist, vpe->col_idx)->rd_base;
gic_write_lpir(d->parent_data->hwirq, rdbase + GICR_INVLPIR);
wait_for_syncr(rdbase);
raw_spin_unlock(&gic_data_rdist_cpu(vpe->col_idx)->rd_lock);
} else {
its_vpe_send_cmd(vpe, its_send_inv);
}
@ -3825,10 +3829,12 @@ static void its_vpe_4_1_invall(struct its_vpe *vpe)
val |= FIELD_PREP(GICR_INVALLR_VPEID, vpe->vpe_id);
/* Target the redistributor this vPE is currently known on */
raw_spin_lock(&gic_data_rdist_cpu(vpe->col_idx)->rd_lock);
rdbase = per_cpu_ptr(gic_rdists->rdist, vpe->col_idx)->rd_base;
gic_write_lpir(val, rdbase + GICR_INVALLR);
wait_for_syncr(rdbase);
raw_spin_unlock(&gic_data_rdist_cpu(vpe->col_idx)->rd_lock);
}
static int its_vpe_4_1_set_vcpu_affinity(struct irq_data *d, void *vcpu_info)

1
drivers/irqchip/irq-gic-v3.c
View file

@ -834,6 +834,7 @@ static int __gic_populate_rdist(struct redist_region *region, void __iomem *ptr)
typer = gic_read_typer(ptr + GICR_TYPER);
if ((typer >> 32) == aff) {
u64 offset = ptr - region->redist_base;
raw_spin_lock_init(&gic_data_rdist()->rd_lock);
gic_data_rdist_rd_base() = ptr;
gic_data_rdist()->phys_base = region->phys_base + offset;

1
include/linux/irqchip/arm-gic-v3.h
View file

@ -652,6 +652,7 @@
struct rdists {
struct {
raw_spinlock_t rd_lock;
void __iomem *rd_base;
struct page *pend_page;
phys_addr_t phys_base;