msi_doorbell_safe returns whether all the registered doorbells implement irq_remapping.
When assigning a PCIe device whose host controller is upstream to an IOMMU, we currently do not know whether the MSI controller is upstream or downstream to the IOMMU. Signed-off-by: Eric Auger <[email protected]> --- include/linux/msi-doorbell.h | 12 ++++++++++++ kernel/irq/msi-doorbell.c | 14 ++++++++++++++ 2 files changed, 26 insertions(+) diff --git a/include/linux/msi-doorbell.h b/include/linux/msi-doorbell.h index abdaaa0..648f239 100644 --- a/include/linux/msi-doorbell.h +++ b/include/linux/msi-doorbell.h @@ -65,6 +65,13 @@ msi_doorbell_lookup(void *chip_data); */ int msi_doorbell_pages(unsigned int order); +/** + * msi_doorbell_safe: return whether all registered doorbells + * do implement irq_remapping and are safe to assign (coarse safety + * assessment) + */ +bool msi_doorbell_safe(void); + #else static inline int @@ -88,6 +95,11 @@ msi_doorbell_pages(unsigned int order) return 0; } +static inline bool +msi_doorbell_safe(void) +{ + return true; +} #endif /* CONFIG_MSI_DOORBELL */ #endif diff --git a/kernel/irq/msi-doorbell.c b/kernel/irq/msi-doorbell.c index 65ca9292..69121c8 100644 --- a/kernel/irq/msi-doorbell.c +++ b/kernel/irq/msi-doorbell.c @@ -132,3 +132,17 @@ int msi_doorbell_pages(unsigned int order) } EXPORT_SYMBOL_GPL(msi_doorbell_pages); +bool msi_doorbell_safe(void) +{ + struct irqchip_doorbell *db; + bool irq_remapping = true; + + mutex_lock(&irqchip_doorbell_mutex); + list_for_each_entry(db, &irqchip_doorbell_list, next) { + irq_remapping &= db->info.irq_remapping; + } + mutex_unlock(&irqchip_doorbell_mutex); + + return irq_remapping; +} +EXPORT_SYMBOL_GPL(msi_doorbell_safe); -- 1.9.1 _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
