4.20-stable review patch. If anyone has any objections, please let me know.
------------------
From: Marc Zyngier marc.zyngier@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: stable@vger.kernel.org Reported-by: Ard Biesheuvel ard.biesheuvel@linaro.org Tested-by: Ard Biesheuvel ard.biesheuvel@linaro.org Signed-off-by: Marc Zyngier marc.zyngier@arm.com Signed-off-by: Greg Kroah-Hartman gregkh@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;