On 2020-02-20 03:11, Zenghui Yu wrote:
Hi Marc,
On 2020/2/18 23:31, Marc Zyngier wrote:
diff --git a/drivers/irqchip/irq-gic-v3-its.c
b/drivers/irqchip/irq-gic-v3-its.c
index 7656b353a95f..0ed286dba827 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -144,7 +144,7 @@ struct event_lpi_map {
u16 *col_map;
irq_hw_number_t lpi_base;
int nr_lpis;
- raw_spinlock_t vlpi_lock;
+ raw_spinlock_t map_lock;
So we use map_lock to protect both LPI's and VLPI's mapping affinity of
a device, and use vpe_lock to protect vPE's affinity, OK.
struct its_vm *vm;
struct its_vlpi_map *vlpi_maps;
int nr_vlpis;
@@ -240,15 +240,33 @@ 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 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) {
+ raw_spin_lock_irqsave(&map->vpe->vpe_lock, *flags);
+ cpu = map->vpe->col_idx;
+ } else {
+ struct its_device *its_dev = irq_data_get_irq_chip_data(d);
+ raw_spin_lock_irqsave(&its_dev->event_map.map_lock, *flags);
+ cpu = its_dev->event_map.col_map[its_get_event_id(d)];
+ }
- return its_dev->event_map.col_map[its_get_event_id(d)];
+ return cpu;
+}
This helper is correct for normal LPIs and VLPIs, but wrong for per-vPE
IRQ (doorbell) and vSGIs. irq_data_get_irq_chip_data() gets confused by
both of them.
Yes, I've fixed that in the current state of the tree last week. Do have
a
look if you can, but it seems to survive on both the model with v4.1 and
my D05.
[...]
- rdbase = per_cpu_ptr(gic_rdists->rdist,
vpe->col_idx)->rd_base;
+ cpu = irq_to_cpuid_lock(d, &flags);
+ rdbase = per_cpu_ptr(gic_rdists->rdist, cpu)->rd_base;
gic_write_lpir(d->parent_data->hwirq, rdbase +
GICR_INVLPIR);
wait_for_syncr(rdbase);
+ irq_to_cpuid_unlock(d, flags);
} else {
its_vpe_send_cmd(vpe, its_send_inv);
}
Do we really need to grab the vpe_lock for those which are belong to
the same irqchip with its_vpe_set_affinity()? The IRQ core code should
already ensure the mutual exclusion among them, wrong?
I've been trying to think about that, but jet-lag keeps getting in the
way.
I empirically think that you are right, but I need to go and check the
various
code paths to be sure. Hopefully I'll have a bit more brain space next
week.
For sure this patch tries to do too many things at once...
M.
--
Jazz is not dead. It just smells funny...
