msi_doorbell_pages sum up the number of iommu pages of a given order requested to map all the registered doorbells. This function will allow to dimension the intermediate physical address (IPA) aperture requested to map the MSI doorbells.
Signed-off-by: Eric Auger <[email protected]> --- v10: creation --- include/linux/msi-doorbell.h | 14 ++++++++++++ kernel/irq/msi-doorbell.c | 52 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 66 insertions(+) diff --git a/include/linux/msi-doorbell.h b/include/linux/msi-doorbell.h index bbc7321..abdaaa0 100644 --- a/include/linux/msi-doorbell.h +++ b/include/linux/msi-doorbell.h @@ -57,6 +57,14 @@ void msi_doorbell_unregister(void *chip_data); struct irq_chip_msi_doorbell_info * msi_doorbell_lookup(void *chip_data); +/** + * msi_doorbell_pages: compute the number of iommu pages of size 1 << order + * requested to map all the registered doorbells + * + * @order: iommu page order + */ +int msi_doorbell_pages(unsigned int order); + #else static inline int @@ -74,6 +82,12 @@ msi_doorbell_lookup(void *chip_data) return NULL; } +static inline int +msi_doorbell_pages(unsigned int order) +{ + return 0; +} + #endif /* CONFIG_MSI_DOORBELL */ #endif diff --git a/kernel/irq/msi-doorbell.c b/kernel/irq/msi-doorbell.c index 84ecca1..65ca9292 100644 --- a/kernel/irq/msi-doorbell.c +++ b/kernel/irq/msi-doorbell.c @@ -80,3 +80,55 @@ msi_doorbell_lookup(void *chip_data) } EXPORT_SYMBOL_GPL(msi_doorbell_lookup); +static int compute_db_mapping_requirements(phys_addr_t addr, size_t size, + unsigned int order) +{ + phys_addr_t offset, granule; + unsigned int nb_pages; + + granule = (uint64_t)(1 << order); + offset = addr & (granule - 1); + size = ALIGN(size + offset, granule); + nb_pages = size >> order; + + return nb_pages; +} + +static int +compute_dbinfo_mapping_requirements(struct irq_chip_msi_doorbell_info *dbinfo, + unsigned int order) +{ + int ret = 0; + + if (!dbinfo->doorbell_is_percpu) { + ret = compute_db_mapping_requirements(dbinfo->global_doorbell, + dbinfo->size, order); + } else { + phys_addr_t __percpu *pbase; + int cpu; + + for_each_possible_cpu(cpu) { + pbase = per_cpu_ptr(dbinfo->percpu_doorbells, cpu); + ret += compute_db_mapping_requirements(*pbase, + dbinfo->size, + order); + } + } + return ret; +} + +int msi_doorbell_pages(unsigned int order) +{ + struct irqchip_doorbell *db; + int ret = 0; + + mutex_lock(&irqchip_doorbell_mutex); + list_for_each_entry(db, &irqchip_doorbell_list, next) { + ret += compute_dbinfo_mapping_requirements(&db->info, order); + } + mutex_unlock(&irqchip_doorbell_mutex); + + return ret; +} +EXPORT_SYMBOL_GPL(msi_doorbell_pages); + -- 1.9.1 _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
