4.20-stable review patch. If anyone has any objections, please let me know.
------------------
From: Marc Zyngier <marc.zyng...@arm.com>
commit 8208d1708b88b412ca97f50a6d951242c88cbbac upstream.
The way we allocate events works fine in most cases, except
when multiple PCI devices share an ITS-visible DevID, and that
one of them is trying to use MultiMSI allocation.
In that case, our allocation is not guaranteed to be zero-based
anymore, and we have to make sure we allocate it on a boundary
that is compatible with the PCI Multi-MSI constraints.
Fix this by allocating the full region upfront instead of iterating
over the number of MSIs. MSI-X are always allocated one by one,
so this shouldn't change anything on that front.
Fixes: b48ac83d6bbc2 ("irqchip: GICv3: ITS: MSI support")
Cc: sta...@vger.kernel.org
Reported-by: Ard Biesheuvel <ard.biesheu...@linaro.org>
Tested-by: Ard Biesheuvel <ard.biesheu...@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyng...@arm.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
drivers/irqchip/irq-gic-v3-its.c | 25 +++++++++++++------------
1 file changed, 13 insertions(+), 12 deletions(-)
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -2399,13 +2399,14 @@ static void its_free_device(struct its_d
kfree(its_dev);
}
-static int its_alloc_device_irq(struct its_device *dev, irq_hw_number_t *hwirq)
+static int its_alloc_device_irq(struct its_device *dev, int nvecs,
irq_hw_number_t *hwirq)
{
int idx;
- idx = find_first_zero_bit(dev->event_map.lpi_map,
- dev->event_map.nr_lpis);
- if (idx == dev->event_map.nr_lpis)
+ idx = bitmap_find_free_region(dev->event_map.lpi_map,
+ dev->event_map.nr_lpis,
+ get_count_order(nvecs));
+ if (idx < 0)
return -ENOSPC;
*hwirq = dev->event_map.lpi_base + idx;
@@ -2501,21 +2502,21 @@ static int its_irq_domain_alloc(struct i
int err;
int i;
- for (i = 0; i < nr_irqs; i++) {
- err = its_alloc_device_irq(its_dev, &hwirq);
- if (err)
- return err;
+ err = its_alloc_device_irq(its_dev, nr_irqs, &hwirq);
+ if (err)
+ return err;
- err = its_irq_gic_domain_alloc(domain, virq + i, hwirq);
+ for (i = 0; i < nr_irqs; i++) {
+ err = its_irq_gic_domain_alloc(domain, virq + i, hwirq + i);
if (err)
return err;
irq_domain_set_hwirq_and_chip(domain, virq + i,
- hwirq, &its_irq_chip, its_dev);
+ hwirq + i, &its_irq_chip,
its_dev);
irqd_set_single_target(irq_desc_get_irq_data(irq_to_desc(virq +
i)));
pr_debug("ID:%d pID:%d vID:%d\n",
- (int)(hwirq - its_dev->event_map.lpi_base),
- (int) hwirq, virq + i);
+ (int)(hwirq + i - its_dev->event_map.lpi_base),
+ (int)(hwirq + i), virq + i);
}
return 0;
