Messages in this thread | | | Date | Wed, 22 Jan 2020 15:22:58 +0000 | From | Marc Zyngier <> | Subject | Re: [PATCH] irqchip/gic-v3-its: Don't confuse get_vlpi_map() by writing DB config |
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On 2020-01-22 11:29, Zenghui Yu wrote: > Hi Marc, > > On 2020/1/22 18:44, Marc Zyngier wrote: >> Hi Zenghui, >> >> Thanks for this. >> >> On 2020-01-22 08:56, Zenghui Yu wrote: >>> When we're writing config for the doorbell interrupt, get_vlpi_map() >>> will >>> get confused by doorbell's d->parent_data hack and find the wrong >>> its_dev >>> as chip data and the wrong event. >>> >>> Fix this issue by making sure no doorbells will be involved before >>> invoking >>> get_vlpi_map(), which restore some of the logic in >>> lpi_write_config(). >>> >>> Fixes: c1d4d5cd203c ("irqchip/gic-v3-its: Add its_vlpi_map helpers") >>> Signed-off-by: Zenghui Yu <yuzenghui@huawei.com> >>> --- >>> >>> This is based on mainline and can't be directly applied to the >>> current >>> irqchip-next. >>> >>> drivers/irqchip/irq-gic-v3-its.c | 5 +++-- >>> 1 file changed, 3 insertions(+), 2 deletions(-) >>> >>> diff --git a/drivers/irqchip/irq-gic-v3-its.c >>> b/drivers/irqchip/irq-gic-v3-its.c >>> index e05673bcd52b..cc8a4fcbd6d6 100644 >>> --- a/drivers/irqchip/irq-gic-v3-its.c >>> +++ b/drivers/irqchip/irq-gic-v3-its.c >>> @@ -1181,12 +1181,13 @@ static struct its_vlpi_map >>> *get_vlpi_map(struct irq_data *d) >>> >>> static void lpi_write_config(struct irq_data *d, u8 clr, u8 set) >>> { >>> - struct its_vlpi_map *map = get_vlpi_map(d); >>> irq_hw_number_t hwirq; >>> void *va; >>> u8 *cfg; >>> >>> - if (map) { >>> + if (irqd_is_forwarded_to_vcpu(d)) { >>> + struct its_vlpi_map *map = get_vlpi_map(d); >>> + >>> va = page_address(map->vm->vprop_page); >>> hwirq = map->vintid; >> >> Shouldn't we fix get_vlpi_map() instead? Something like (untested): >> >> diff --git a/drivers/irqchip/irq-gic-v3-its.c >> b/drivers/irqchip/irq-gic-v3-its.c >> index e05673bcd52b..b704214390c0 100644 >> --- a/drivers/irqchip/irq-gic-v3-its.c >> +++ b/drivers/irqchip/irq-gic-v3-its.c >> @@ -1170,13 +1170,14 @@ static void its_send_vclear(struct its_device >> *dev, u32 event_id) >> */ >> static struct its_vlpi_map *get_vlpi_map(struct irq_data *d) >> { >> - struct its_device *its_dev = irq_data_get_irq_chip_data(d); >> - u32 event = its_get_event_id(d); >> + if (irqd_is_forwarded_to_vcpu(d)) { >> + struct its_device *its_dev = irq_data_get_irq_chip_data(d); >> + u32 event = its_get_event_id(d); >> >> - if (!irqd_is_forwarded_to_vcpu(d)) >> - return NULL; >> + return dev_event_to_vlpi_map(its_dev, event); >> + } >> >> - return dev_event_to_vlpi_map(its_dev, event); >> + return NULL; >> } >> >> static void lpi_write_config(struct irq_data *d, u8 clr, u8 set) >> >> >> Or am I missing the actual problem? > > No. I also thought about fixing the issue by this way and I'm OK with > both approaches.
OK, thanks. I've added this to irqchip-next[1], and rebased the v4.1 series on top of it. That way, the fix will trickle down to stable without conflicts.
I've also given it a go on D05 with GICv4 enabled, and nothing caught fire.
M.
[1] https://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms.git/commit/?h=irq/irqchip-next&id=093bf439fee0d40ade7e309c1288b409cdc3b38f -- Jazz is not dead. It just smells funny...
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