| Message ID | 1461831730-5575-8-git-send-email-eric.auger@linaro.org |
|---|---|
| State | New |
| Headers | show |
Hi Marc, On 05/04/2016 03:21 PM, Marc Zyngier wrote: > On 28/04/16 09:22, Eric Auger wrote: >> 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 <eric.auger@linaro.org> >> >> --- >> 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 | 87 ++++++++++++++++++++++++++++++++++++++++++++++++++------ >> 1 file changed, 79 insertions(+), 8 deletions(-) >> >> diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c >> index 72bf4d6..d5f95e6 100644 >> --- a/kernel/irq/msi.c >> +++ b/kernel/irq/msi.c >> @@ -14,6 +14,8 @@ >> #include <linux/irq.h> >> #include <linux/irqdomain.h> >> #include <linux/msi.h> >> +#include <linux/msi-iommu.h> >> +#include <linux/iommu.h> >> >> /* Temparory solution for building, will be removed later */ >> #include <linux/pci.h> >> @@ -322,6 +324,56 @@ 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) >> +{ >> + for (; data; data = data->parent_data) { >> + struct device *dev = >> + msi_desc_to_dev(irq_data_get_msi_desc(data)); >> + struct irq_chip *chip = irq_data_get_irq_chip(data); >> + const struct irq_chip_msi_doorbell_info *dbinfo; >> + struct iommu_domain *domain; >> + phys_addr_t __percpu *db_addr; >> + dma_addr_t iova; >> + int ret = 0, i; >> + >> + domain = iommu_msi_domain(dev); >> + if (!domain) >> + continue; >> + >> + if (!chip->msi_doorbell_info) >> + continue; >> + >> + dbinfo = chip->msi_doorbell_info(data); >> + if (!dbinfo) >> + return -EINVAL; >> + >> + for (i = 0; i < dbinfo->nb_doorbells; i++) { >> + db_addr = per_cpu_ptr(dbinfo->percpu_doorbells, i); >> + if (map) { >> + ret = iommu_msi_get_doorbell_iova(domain, >> + *db_addr, >> + dbinfo->size, >> + dbinfo->prot, >> + &iova); >> + if (ret) >> + return ret; >> + } else >> + iommu_msi_put_doorbell_iova(domain, *db_addr); >> + } >> + break; >> + } >> + return 0; >> +} > > I'm really not fond of this whole loop. Could you try to decouple the > irq_data parsing (looking for a msi_doorbell_info method) from the > actual mapping/unmapping? This would make it a lot more readable. > Something along the lines of: Just sent v9 where I addressed all your comments. Please let me know whether this looks better. > > struct device *dev; > struct irq_chip *chip; > struct iommu_domain *domain; > const struct irq_chip_msi_doorbell_info *dbinfo; > > while (data) { > dev = msi_desc_to_dev(irq_data_get_msi_desc(data)); > domain = iommu_msi_domain(dev); > if (!domain) > continue; > > chip = irq_data_get_irq_chip(data); > if (chip->msi_doorbell_info) > break; > > data = data->parent; > } > > if (!data) > return 0; > > dbinfo = chip->msi_doorbell_info(data); > if (!dbinfo) > return -EINVAL; > > [... handle mapping/unmapping here ...] > >> + >> +/** >> * 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 +404,26 @@ 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++) { >> + ret = msi_handle_doorbell_mappings( >> + irq_get_irq_data(virq + i), true); > > Do not be afraid of longer lines. Or if you are, create an intermediate > variable. But this kind of construct makes my brain work harder, and I > hate the feeling... ;-) Yes I am afraid of checkpatch and I do my utmost to abide by its law ;-) Well, let me know if the v9 is of any relief for your brain ;-) Thanks for your time! Eric > >> + if (ret) >> + break; >> + } >> + if (ret) { >> + for (; i >= 0; i--) >> + msi_handle_doorbell_mappings( >> + irq_get_irq_data(virq + i), false); >> + irq_domain_free_irqs(virq, desc->nvec_used); >> + desc->irq = 0; >> + goto error; >> + } >> } >> >> if (ops->msi_finish) >> @@ -377,6 +438,13 @@ 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 +464,9 @@ 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; >> } >> > > Thanks, > > M. >
diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c index 72bf4d6..d5f95e6 100644 --- a/kernel/irq/msi.c +++ b/kernel/irq/msi.c @@ -14,6 +14,8 @@ #include <linux/irq.h> #include <linux/irqdomain.h> #include <linux/msi.h> +#include <linux/msi-iommu.h> +#include <linux/iommu.h> /* Temparory solution for building, will be removed later */ #include <linux/pci.h> @@ -322,6 +324,56 @@ 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) +{ + for (; data; data = data->parent_data) { + struct device *dev = + msi_desc_to_dev(irq_data_get_msi_desc(data)); + struct irq_chip *chip = irq_data_get_irq_chip(data); + const struct irq_chip_msi_doorbell_info *dbinfo; + struct iommu_domain *domain; + phys_addr_t __percpu *db_addr; + dma_addr_t iova; + int ret = 0, i; + + domain = iommu_msi_domain(dev); + if (!domain) + continue; + + if (!chip->msi_doorbell_info) + continue; + + dbinfo = chip->msi_doorbell_info(data); + if (!dbinfo) + return -EINVAL; + + for (i = 0; i < dbinfo->nb_doorbells; i++) { + db_addr = per_cpu_ptr(dbinfo->percpu_doorbells, i); + if (map) { + ret = iommu_msi_get_doorbell_iova(domain, + *db_addr, + dbinfo->size, + dbinfo->prot, + &iova); + if (ret) + return ret; + } else + iommu_msi_put_doorbell_iova(domain, *db_addr); + } + break; + } + 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 +404,26 @@ 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++) { + ret = msi_handle_doorbell_mappings( + irq_get_irq_data(virq + i), true); + if (ret) + break; + } + if (ret) { + for (; i >= 0; i--) + msi_handle_doorbell_mappings( + irq_get_irq_data(virq + i), false); + irq_domain_free_irqs(virq, desc->nvec_used); + desc->irq = 0; + goto error; + } } if (ops->msi_finish) @@ -377,6 +438,13 @@ 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 +464,9 @@ 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; }
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 <eric.auger@linaro.org> --- 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 | 87 ++++++++++++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 79 insertions(+), 8 deletions(-) -- 1.9.1