| Message ID | 1415991397-9618-9-git-send-email-will.deacon@arm.com |
|---|---|
| State | Accepted |
| Commit | 4bb25789ed28228a52c030bf28edb2fcdb214be8 |
| Headers | show |
Hi Will, On 14/11/14 18:56, Will Deacon wrote: > This patch plumbs the existing ARM IOMMU DMA infrastructure (which isn't > actually called outside of a few drivers) into arch_setup_dma_ops, so > that we can use IOMMUs for DMA transfers in a more generic fashion. > > Since this significantly complicates the arch_setup_dma_ops function, > it is moved out of line into dma-mapping.c. If CONFIG_ARM_DMA_USE_IOMMU > is not set, the iommu parameter is ignored and the normal ops are used > instead. > > Signed-off-by: Will Deacon <will.deacon@arm.com> [...] > +static bool arm_setup_iommu_dma_ops(struct device *dev, u64 dma_base, u64 size, > + struct iommu_ops *iommu) > +{ > + struct dma_iommu_mapping *mapping; > + > + mapping = arm_iommu_create_mapping(dev->bus, dma_base, size); > + if (IS_ERR(mapping)) { > + pr_warn("Failed to create %llu-byte IOMMU mapping for device %s\n", > + size, dev_name(dev)); > + return false; > + } > + > + if (arm_iommu_attach_device(dev, mapping)) { > + pr_warn("Failed to attached device %s to IOMMU_mapping\n", > + dev_name(dev)); > + arm_iommu_release_mapping(mapping); > + return false; > + } > + > + return true; > +} > + > +static void arm_teardown_iommu_dma_ops(struct device *dev) > +{ > + struct dma_iommu_mapping *mapping = dev->archdata.mapping; > + > + arm_iommu_detach_device(dev); > + arm_iommu_release_mapping(mapping); > +} > + > +#else > + > +static bool arm_setup_iommu_dma_ops(struct device *dev, u64 dma_base, u64 size, > + struct iommu_ops *iommu) > +{ > + return false; > +} > + > +static void arm_teardown_iommu_dma_ops(struct device *dev) { } > + > +#define arm_get_iommu_dma_map_ops arm_get_dma_map_ops > + > +#endif /* CONFIG_ARM_DMA_USE_IOMMU */ > + > +static struct dma_map_ops *arm_get_dma_map_ops(bool coherent) > +{ > + return coherent ? &arm_coherent_dma_ops : &arm_dma_ops; > +} > + > +void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size, > + struct iommu_ops *iommu, bool coherent) > +{ > + struct dma_map_ops *dma_ops; > + > + if (arm_setup_iommu_dma_ops(dev, dma_base, size, iommu)) Is the loss of a null check on iommu (compared to previous versions) intentional? It looks like you're always going to call arm_setup_iommu_dma_ops here for everything regardless, and given that that doesn't even look at the iommu parameter, relying on it to somehow fail correctly smells a bit off. Robin. > + dma_ops = arm_get_iommu_dma_map_ops(coherent); > + else > + dma_ops = arm_get_dma_map_ops(coherent); > + > + set_dma_ops(dev, dma_ops); > +} > + > +void arch_teardown_dma_ops(struct device *dev) > +{ > + arm_teardown_iommu_dma_ops(dev); > +} >
On Mon, Nov 17, 2014 at 11:29:23AM +0000, Robin Murphy wrote: > On 14/11/14 18:56, Will Deacon wrote: > > This patch plumbs the existing ARM IOMMU DMA infrastructure (which isn't > > actually called outside of a few drivers) into arch_setup_dma_ops, so > > that we can use IOMMUs for DMA transfers in a more generic fashion. > > > > Since this significantly complicates the arch_setup_dma_ops function, > > it is moved out of line into dma-mapping.c. If CONFIG_ARM_DMA_USE_IOMMU > > is not set, the iommu parameter is ignored and the normal ops are used > > instead. > > > > Signed-off-by: Will Deacon <will.deacon@arm.com> > > [...] > > > +static bool arm_setup_iommu_dma_ops(struct device *dev, u64 dma_base, u64 size, > > + struct iommu_ops *iommu) > > +{ > > + struct dma_iommu_mapping *mapping; > > + > > + mapping = arm_iommu_create_mapping(dev->bus, dma_base, size); > > + if (IS_ERR(mapping)) { > > + pr_warn("Failed to create %llu-byte IOMMU mapping for device %s\n", > > + size, dev_name(dev)); > > + return false; > > + } > > + > > + if (arm_iommu_attach_device(dev, mapping)) { > > + pr_warn("Failed to attached device %s to IOMMU_mapping\n", > > + dev_name(dev)); > > + arm_iommu_release_mapping(mapping); > > + return false; > > + } > > + > > + return true; > > +} > > + > > +static void arm_teardown_iommu_dma_ops(struct device *dev) > > +{ > > + struct dma_iommu_mapping *mapping = dev->archdata.mapping; > > + > > + arm_iommu_detach_device(dev); > > + arm_iommu_release_mapping(mapping); > > +} > > + > > +#else > > + > > +static bool arm_setup_iommu_dma_ops(struct device *dev, u64 dma_base, u64 size, > > + struct iommu_ops *iommu) > > +{ > > + return false; > > +} > > + > > +static void arm_teardown_iommu_dma_ops(struct device *dev) { } > > + > > +#define arm_get_iommu_dma_map_ops arm_get_dma_map_ops > > + > > +#endif /* CONFIG_ARM_DMA_USE_IOMMU */ > > + > > +static struct dma_map_ops *arm_get_dma_map_ops(bool coherent) > > +{ > > + return coherent ? &arm_coherent_dma_ops : &arm_dma_ops; > > +} > > + > > +void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size, > > + struct iommu_ops *iommu, bool coherent) > > +{ > > + struct dma_map_ops *dma_ops; > > + > > + if (arm_setup_iommu_dma_ops(dev, dma_base, size, iommu)) > > Is the loss of a null check on iommu (compared to previous versions) > intentional? It looks like you're always going to call > arm_setup_iommu_dma_ops here for everything regardless, and given that > that doesn't even look at the iommu parameter, relying on it to somehow > fail correctly smells a bit off. Thanks, I'll fix that. I started writing a full implementation based off a hypothetical ->get_default_domain callback (as suggested by Joerg), so this is a hangover from that experiment. Will
diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h index f3c0d953f6a2..9410b7e548fc 100644 --- a/arch/arm/include/asm/dma-mapping.h +++ b/arch/arm/include/asm/dma-mapping.h @@ -121,14 +121,12 @@ static inline unsigned long dma_max_pfn(struct device *dev) } #define dma_max_pfn(dev) dma_max_pfn(dev) -static inline void arch_setup_dma_ops(struct device *dev, u64 dma_base, - u64 size, struct iommu_ops *iommu, - bool coherent) -{ - if (coherent) - set_dma_ops(dev, &arm_coherent_dma_ops); -} #define arch_setup_dma_ops arch_setup_dma_ops +extern void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size, + struct iommu_ops *iommu, bool coherent); + +#define arch_teardown_dma_ops arch_teardown_dma_ops +extern void arch_teardown_dma_ops(struct device *dev); static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr) { diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index e8907117861e..f15eae5e0513 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -1947,9 +1947,8 @@ EXPORT_SYMBOL_GPL(arm_iommu_release_mapping); * arm_iommu_create_mapping) * * Attaches specified io address space mapping to the provided device, - * this replaces the dma operations (dma_map_ops pointer) with the - * IOMMU aware version. More than one client might be attached to - * the same io address space mapping. + * More than one client might be attached to the same io address space + * mapping. */ int arm_iommu_attach_device(struct device *dev, struct dma_iommu_mapping *mapping) @@ -1962,7 +1961,6 @@ int arm_iommu_attach_device(struct device *dev, kref_get(&mapping->kref); dev->archdata.mapping = mapping; - set_dma_ops(dev, &iommu_ops); pr_debug("Attached IOMMU controller to %s device.\n", dev_name(dev)); return 0; @@ -1974,7 +1972,6 @@ EXPORT_SYMBOL_GPL(arm_iommu_attach_device); * @dev: valid struct device pointer * * Detaches the provided device from a previously attached map. - * This voids the dma operations (dma_map_ops pointer) */ void arm_iommu_detach_device(struct device *dev) { @@ -1989,10 +1986,79 @@ void arm_iommu_detach_device(struct device *dev) iommu_detach_device(mapping->domain, dev); kref_put(&mapping->kref, release_iommu_mapping); dev->archdata.mapping = NULL; - set_dma_ops(dev, NULL); pr_debug("Detached IOMMU controller from %s device.\n", dev_name(dev)); } EXPORT_SYMBOL_GPL(arm_iommu_detach_device); -#endif +static struct dma_map_ops *arm_get_iommu_dma_map_ops(bool coherent) +{ + return coherent ? &iommu_coherent_ops : &iommu_ops; +} + +static bool arm_setup_iommu_dma_ops(struct device *dev, u64 dma_base, u64 size, + struct iommu_ops *iommu) +{ + struct dma_iommu_mapping *mapping; + + mapping = arm_iommu_create_mapping(dev->bus, dma_base, size); + if (IS_ERR(mapping)) { + pr_warn("Failed to create %llu-byte IOMMU mapping for device %s\n", + size, dev_name(dev)); + return false; + } + + if (arm_iommu_attach_device(dev, mapping)) { + pr_warn("Failed to attached device %s to IOMMU_mapping\n", + dev_name(dev)); + arm_iommu_release_mapping(mapping); + return false; + } + + return true; +} + +static void arm_teardown_iommu_dma_ops(struct device *dev) +{ + struct dma_iommu_mapping *mapping = dev->archdata.mapping; + + arm_iommu_detach_device(dev); + arm_iommu_release_mapping(mapping); +} + +#else + +static bool arm_setup_iommu_dma_ops(struct device *dev, u64 dma_base, u64 size, + struct iommu_ops *iommu) +{ + return false; +} + +static void arm_teardown_iommu_dma_ops(struct device *dev) { } + +#define arm_get_iommu_dma_map_ops arm_get_dma_map_ops + +#endif /* CONFIG_ARM_DMA_USE_IOMMU */ + +static struct dma_map_ops *arm_get_dma_map_ops(bool coherent) +{ + return coherent ? &arm_coherent_dma_ops : &arm_dma_ops; +} + +void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size, + struct iommu_ops *iommu, bool coherent) +{ + struct dma_map_ops *dma_ops; + + if (arm_setup_iommu_dma_ops(dev, dma_base, size, iommu)) + dma_ops = arm_get_iommu_dma_map_ops(coherent); + else + dma_ops = arm_get_dma_map_ops(coherent); + + set_dma_ops(dev, dma_ops); +} + +void arch_teardown_dma_ops(struct device *dev) +{ + arm_teardown_iommu_dma_ops(dev); +}
This patch plumbs the existing ARM IOMMU DMA infrastructure (which isn't actually called outside of a few drivers) into arch_setup_dma_ops, so that we can use IOMMUs for DMA transfers in a more generic fashion. Since this significantly complicates the arch_setup_dma_ops function, it is moved out of line into dma-mapping.c. If CONFIG_ARM_DMA_USE_IOMMU is not set, the iommu parameter is ignored and the normal ops are used instead. Signed-off-by: Will Deacon <will.deacon@arm.com> --- arch/arm/include/asm/dma-mapping.h | 12 +++--- arch/arm/mm/dma-mapping.c | 80 ++++++++++++++++++++++++++++++++++---- 2 files changed, 78 insertions(+), 14 deletions(-)