From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Auger Subject: [PATCH v12 05/11] genirq/msi: msi_doorbell_calc_pages Date: Tue, 2 Aug 2016 17:23:31 +0000 Message-ID: <1470158617-7022-6-git-send-email-eric.auger@redhat.com> References: <1470158617-7022-1-git-send-email-eric.auger@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: drjones-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, kvm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Manish.Jaggi-M3mlKVOIwJVv6pq1l3V1OdBPR1lH4CV8@public.gmane.org, p.fedin-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, pranav.sawargaonkar-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, dennis.chen-5wv7dgnIgG8@public.gmane.org, robert.richter-M3mlKVOIwJVv6pq1l3V1OdBPR1lH4CV8@public.gmane.org, yehuday-eYqpPyKDWXRBDgjK7y7TUQ@public.gmane.org To: eric.auger-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, eric.auger.pro-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, christoffer.dall-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, marc.zyngier-5wv7dgnIgG8@public.gmane.org, robin.murphy-5wv7dgnIgG8@public.gmane.org, alex.williamson-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, will.deacon-5wv7dgnIgG8@public.gmane.org, joro-zLv9SwRftAIdnm+yROfE0A@public.gmane.org, tglx-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org, jason-NLaQJdtUoK4Be96aLqz0jA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org Return-path: In-Reply-To: <1470158617-7022-1-git-send-email-eric.auger-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org List-Id: kvm.vger.kernel.org msi_doorbell_calc_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 --- v11 -> v12: - fix style issues: remove useless line break, remove pointless braces, fix kernel-doc comments - reword commit message - rename msi_doorbell_pages into msi_doorbell_calc_pages - rename static compute* functions v10: creation --- include/linux/msi-doorbell.h | 14 ++++++++++ kernel/irq/msi-doorbell.c | 64 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 78 insertions(+) diff --git a/include/linux/msi-doorbell.h b/include/linux/msi-doorbell.h index a2a033b..bbedb3b 100644 --- a/include/linux/msi-doorbell.h +++ b/include/linux/msi-doorbell.h @@ -38,6 +38,15 @@ msi_doorbell_register_global(phys_addr_t base, size_t size, */ void msi_doorbell_unregister_global(struct msi_doorbell_info *db); +/** + * msi_doorbell_calc_pages - compute the number of pages + * requested to map all the registered doorbells + * @order: iommu page order + * + * Return: the number of requested pages + */ +int msi_doorbell_calc_pages(unsigned int order); + #else static inline struct msi_doorbell_info * @@ -50,6 +59,11 @@ msi_doorbell_register_global(phys_addr_t base, size_t size, static inline void msi_doorbell_unregister_global(struct msi_doorbell_info *db) {} +static inline int msi_doorbell_calc_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 e3e0d95..5c6c2aa 100644 --- a/kernel/irq/msi-doorbell.c +++ b/kernel/irq/msi-doorbell.c @@ -66,3 +66,67 @@ void msi_doorbell_unregister_global(struct msi_doorbell_info *dbinfo) kfree(db); } EXPORT_SYMBOL_GPL(msi_doorbell_unregister_global); + +/** + * calc_region_reqs - compute the number of pages requested to map a region + * + * @addr: physical base address of the region + * @size: size of the region + * @order: the page order + * + * Return: the number of requested pages to map this region + */ +static int calc_region_reqs(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; +} + +/** + * calc_dbinfo_reqs - compute the number of pages requested to map a given + * MSI doorbell + * + * @dbi: doorbell info descriptor + * @order: page order + * + * Return: the number of requested pages to map this doorbell + */ +static int calc_dbinfo_reqs(struct msi_doorbell_info *dbi, unsigned int order) +{ + int ret = 0; + + if (!dbi->doorbell_is_percpu) { + ret = calc_region_reqs(dbi->global_doorbell, dbi->size, order); + } else { + phys_addr_t __percpu *pbase; + int cpu; + + for_each_possible_cpu(cpu) { + pbase = per_cpu_ptr(dbi->percpu_doorbells, cpu); + ret += calc_region_reqs(*pbase, dbi->size, order); + } + } + return ret; +} + +int msi_doorbell_calc_pages(unsigned int order) +{ + struct msi_doorbell *db; + int ret = 0; + + mutex_lock(&msi_doorbell_mutex); + list_for_each_entry(db, &msi_doorbell_list, next) + ret += calc_dbinfo_reqs(&db->info, order); + + mutex_unlock(&msi_doorbell_mutex); + + return ret; +} +EXPORT_SYMBOL_GPL(msi_doorbell_calc_pages); -- 1.9.1