From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Auger Subject: [PATCH v10 8/9] genirq/msi: map/unmap the MSI doorbells on msi_domain_alloc/free_irqs Date: Tue, 7 Jun 2016 16:01:27 +0000 Message-ID: <1465315288-5931-9-git-send-email-eric.auger@redhat.com> References: <1465315288-5931-1-git-send-email-eric.auger@redhat.com> Return-path: In-Reply-To: <1465315288-5931-1-git-send-email-eric.auger@redhat.com> Sender: linux-kernel-owner@vger.kernel.org To: eric.auger@redhat.com, eric.auger.pro@gmail.com, robin.murphy@arm.com, alex.williamson@redhat.com, will.deacon@arm.com, joro@8bytes.org, tglx@linutronix.de, jason@lakedaemon.net, marc.zyngier@arm.com, christoffer.dall@linaro.org, linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org, Bharat.Bhushan@freescale.com, pranav.sawargaonkar@gmail.com, p.fedin@samsung.com, iommu@lists.linux-foundation.org, Jean-Philippe.Brucker@arm.com, julien.grall@arm.com, yehuday@marvell.com List-Id: iommu@lists.linux-foundation.org This patch handles the iommu mapping of MSI doorbells that require to be mapped in an iommu domain. This happens on msi_domain_alloc/free_irqs since this is called in code that can sleep (pci_enable/disable_msi): iommu_map/unmap is not stated as atomic. On msi_domain_(de)activate and msi_domain_set_affinity, which must be atomic, we just lookup for this pre-allocated/mapped IOVA. Signed-off-by: Eric Auger --- v9 -> v10: - use irqchip API to lookup for the chip_data's doorbell v8 -> v9: - decouple irq_data parsing from the actual mapping/unmapping v7 -> v8: - new percpu pointer type - exit from the irq domain hierarchy parsing on first map/unmap success - reset desc->irq to 0 on mapping failure v7: creation --- kernel/irq/msi.c | 106 ++++++++++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 98 insertions(+), 8 deletions(-) diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c index 72bf4d6..a78db5f 100644 --- a/kernel/irq/msi.c +++ b/kernel/irq/msi.c @@ -14,6 +14,9 @@ #include #include #include +#include +#include +#include /* Temparory solution for building, will be removed later */ #include @@ -322,6 +325,71 @@ int msi_domain_populate_irqs(struct irq_domain *domain, struct device *dev, } /** + * msi_handle_doorbell_mappings: in case the irq data corresponds to an + * MSI that requires iommu mapping, traverse the irq domain hierarchy + * to retrieve the doorbells to handle and iommu_map/unmap them according + * to @map boolean. + * + * @data: irq data handle + * @map: mapping if true, unmapping if false + */ +static int msi_handle_doorbell_mappings(struct irq_data *data, bool map) +{ + const struct irq_chip_msi_doorbell_info *dbinfo; + struct iommu_domain *domain; + struct device *dev; + dma_addr_t iova; + void *chip_data; + int ret = 0, cpu; + + while (data) { + dev = msi_desc_to_dev(irq_data_get_msi_desc(data)); + domain = iommu_msi_domain(dev); + if (domain) { + chip_data = irq_data_get_irq_chip_data(data); + dbinfo = msi_doorbell_lookup(chip_data); + if (dbinfo) + break; + } + data = data->parent_data; + } + + if (!data) + return 0; + + if (!dbinfo->doorbell_is_percpu) { + if (!map) { + iommu_msi_put_doorbell_iova(domain, + dbinfo->global_doorbell); + return 0; + } + return iommu_msi_get_doorbell_iova(domain, + dbinfo->global_doorbell, + dbinfo->size, dbinfo->prot, + &iova); + } + + /* percpu doorbells */ + for_each_possible_cpu(cpu) { + phys_addr_t __percpu *db_addr = + per_cpu_ptr(dbinfo->percpu_doorbells, cpu); + + if (!map) { + iommu_msi_put_doorbell_iova(domain, *db_addr); + } else { + + ret = iommu_msi_get_doorbell_iova(domain, *db_addr, + dbinfo->size, + dbinfo->prot, &iova); + if (ret) + return ret; + } + } + + return 0; +} + +/** * msi_domain_alloc_irqs - Allocate interrupts from a MSI interrupt domain * @domain: The domain to allocate from * @dev: Pointer to device struct of the device for which the interrupts @@ -352,17 +420,29 @@ int msi_domain_alloc_irqs(struct irq_domain *domain, struct device *dev, virq = __irq_domain_alloc_irqs(domain, virq, desc->nvec_used, dev_to_node(dev), &arg, false); - if (virq < 0) { - ret = -ENOSPC; - if (ops->handle_error) - ret = ops->handle_error(domain, desc, ret); - if (ops->msi_finish) - ops->msi_finish(&arg, ret); - return ret; - } + if (virq < 0) + goto error; for (i = 0; i < desc->nvec_used; i++) irq_set_msi_desc_off(virq, i, desc); + + for (i = 0; i < desc->nvec_used; i++) { + struct irq_data *d = irq_get_irq_data(virq + i); + + ret = msi_handle_doorbell_mappings(d, true); + if (ret) + break; + } + if (ret) { + for (; i >= 0; i--) { + struct irq_data *d = irq_get_irq_data(virq + i); + + msi_handle_doorbell_mappings(d, false); + } + irq_domain_free_irqs(virq, desc->nvec_used); + desc->irq = 0; + goto error; + } } if (ops->msi_finish) @@ -377,6 +457,13 @@ int msi_domain_alloc_irqs(struct irq_domain *domain, struct device *dev, } return 0; +error: + ret = -ENOSPC; + if (ops->handle_error) + ret = ops->handle_error(domain, desc, ret); + if (ops->msi_finish) + ops->msi_finish(&arg, ret); + return ret; } /** @@ -396,6 +483,9 @@ void msi_domain_free_irqs(struct irq_domain *domain, struct device *dev) * entry. If that's the case, don't do anything. */ if (desc->irq) { + msi_handle_doorbell_mappings( + irq_get_irq_data(desc->irq), + false); irq_domain_free_irqs(desc->irq, desc->nvec_used); desc->irq = 0; } -- 1.9.1