From 4f3f8d9db359bbc780d482849f2a9c8b12f910b6 Mon Sep 17 00:00:00 2001 From: Ohad Ben-Cohen Date: Tue, 13 Sep 2011 15:25:23 -0400 Subject: iommu/core: Add fault reporting mechanism Add iommu fault report mechanism to the IOMMU API, so implementations could report about mmu faults (translation errors, hardware errors, etc..). Fault reports can be used in several ways: - mere logging - reset the device that accessed the faulting address (may be necessary in case the device is a remote processor for example) - implement dynamic PTE/TLB loading A dedicated iommu_set_fault_handler() API has been added to allow users, who are interested to receive such reports, to provide their handler. Signed-off-by: Ohad Ben-Cohen Signed-off-by: Joerg Roedel --- include/linux/iommu.h | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 51 insertions(+) (limited to 'include') diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 9940319d6f9..d084e8777e0 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -26,9 +26,18 @@ #define IOMMU_CACHE (4) /* DMA cache coherency */ struct device; +struct iommu_domain; + +/* iommu fault flags */ +#define IOMMU_FAULT_READ 0x0 +#define IOMMU_FAULT_WRITE 0x1 + +typedef int (*iommu_fault_handler_t)(struct iommu_domain *, + struct device *, unsigned long, int); struct iommu_domain { void *priv; + iommu_fault_handler_t handler; }; #define IOMMU_CAP_CACHE_COHERENCY 0x1 @@ -67,6 +76,43 @@ extern phys_addr_t iommu_iova_to_phys(struct iommu_domain *domain, unsigned long iova); extern int iommu_domain_has_cap(struct iommu_domain *domain, unsigned long cap); +extern void iommu_set_fault_handler(struct iommu_domain *domain, + iommu_fault_handler_t handler); + +/** + * report_iommu_fault() - report about an IOMMU fault to the IOMMU framework + * @domain: the iommu domain where the fault has happened + * @dev: the device where the fault has happened + * @iova: the faulting address + * @flags: mmu fault flags (e.g. IOMMU_FAULT_READ/IOMMU_FAULT_WRITE/...) + * + * This function should be called by the low-level IOMMU implementations + * whenever IOMMU faults happen, to allow high-level users, that are + * interested in such events, to know about them. + * + * This event may be useful for several possible use cases: + * - mere logging of the event + * - dynamic TLB/PTE loading + * - if restarting of the faulting device is required + * + * Returns 0 on success and an appropriate error code otherwise (if dynamic + * PTE/TLB loading will one day be supported, implementations will be able + * to tell whether it succeeded or not according to this return value). + */ +static inline int report_iommu_fault(struct iommu_domain *domain, + struct device *dev, unsigned long iova, int flags) +{ + int ret = 0; + + /* + * if upper layers showed interest and installed a fault handler, + * invoke it. + */ + if (domain->handler) + ret = domain->handler(domain, dev, iova, flags); + + return ret; +} #else /* CONFIG_IOMMU_API */ @@ -123,6 +169,11 @@ static inline int domain_has_cap(struct iommu_domain *domain, return 0; } +static inline void iommu_set_fault_handler(struct iommu_domain *domain, + iommu_fault_handler_t handler) +{ +} + #endif /* CONFIG_IOMMU_API */ #endif /* __LINUX_IOMMU_H */ -- cgit v1.2.3 From 0ed6d2d27bcc2ace454a8c55446e1bc3efd2d529 Mon Sep 17 00:00:00 2001 From: Ohad Ben-Cohen Date: Tue, 27 Sep 2011 07:36:40 -0400 Subject: iommu/core: let drivers know if an iommu fault handler isn't installed Make report_iommu_fault() return -ENOSYS whenever an iommu fault handler isn't installed, so IOMMU drivers can then do their own platform-specific default behavior if they wanted. Fault handlers can still return -ENOSYS in case they want to elicit the default behavior of the IOMMU drivers. Signed-off-by: Ohad Ben-Cohen Signed-off-by: Joerg Roedel --- include/linux/iommu.h | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/iommu.h b/include/linux/iommu.h index d084e8777e0..ddad0ae0a43 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -98,11 +98,15 @@ extern void iommu_set_fault_handler(struct iommu_domain *domain, * Returns 0 on success and an appropriate error code otherwise (if dynamic * PTE/TLB loading will one day be supported, implementations will be able * to tell whether it succeeded or not according to this return value). + * + * Specifically, -ENOSYS is returned if a fault handler isn't installed + * (though fault handlers can also return -ENOSYS, in case they want to + * elicit the default behavior of the IOMMU drivers). */ static inline int report_iommu_fault(struct iommu_domain *domain, struct device *dev, unsigned long iova, int flags) { - int ret = 0; + int ret = -ENOSYS; /* * if upper layers showed interest and installed a fault handler, -- cgit v1.2.3 From 39d4ebb95925046863dc0ef2698dfcf2c1f1dcbe Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Tue, 6 Sep 2011 16:48:40 +0200 Subject: iommu/core: Define iommu_ops and register_iommu only with CONFIG_IOMMU_API This makes it impossible to compile an iommu driver into the kernel without selecting CONFIG_IOMMU_API. Signed-off-by: Joerg Roedel --- include/linux/iommu.h | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) (limited to 'include') diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 9940319d6f9..6470cd87b4e 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -34,6 +34,8 @@ struct iommu_domain { #define IOMMU_CAP_CACHE_COHERENCY 0x1 #define IOMMU_CAP_INTR_REMAP 0x2 /* isolates device intrs */ +#ifdef CONFIG_IOMMU_API + struct iommu_ops { int (*domain_init)(struct iommu_domain *domain); void (*domain_destroy)(struct iommu_domain *domain); @@ -49,8 +51,6 @@ struct iommu_ops { unsigned long cap); }; -#ifdef CONFIG_IOMMU_API - extern void register_iommu(struct iommu_ops *ops); extern bool iommu_found(void); extern struct iommu_domain *iommu_domain_alloc(void); @@ -70,9 +70,7 @@ extern int iommu_domain_has_cap(struct iommu_domain *domain, #else /* CONFIG_IOMMU_API */ -static inline void register_iommu(struct iommu_ops *ops) -{ -} +struct iommu_ops {}; static inline bool iommu_found(void) { -- cgit v1.2.3 From ff21776d12ff7993a6b236b8273ef62777d25dfb Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Fri, 26 Aug 2011 16:48:26 +0200 Subject: Driver core: Add iommu_ops to bus_type This is the starting point to make the iommu_ops used for the iommu-api a per-bus-type structure. It is required to easily implement bus-specific setup in the iommu-layer. The first user will be the iommu-group attribute in sysfs. Acked-by: Greg Kroah-Hartman Signed-off-by: Joerg Roedel --- include/linux/device.h | 6 ++++++ include/linux/iommu.h | 2 ++ 2 files changed, 8 insertions(+) (limited to 'include') diff --git a/include/linux/device.h b/include/linux/device.h index c20dfbfc49b..e838e143baa 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -33,6 +33,7 @@ struct class; struct subsys_private; struct bus_type; struct device_node; +struct iommu_ops; struct bus_attribute { struct attribute attr; @@ -67,6 +68,9 @@ extern void bus_remove_file(struct bus_type *, struct bus_attribute *); * @resume: Called to bring a device on this bus out of sleep mode. * @pm: Power management operations of this bus, callback the specific * device driver's pm-ops. + * @iommu_ops IOMMU specific operations for this bus, used to attach IOMMU + * driver implementations to a bus and allow the driver to do + * bus-specific setup * @p: The private data of the driver core, only the driver core can * touch this. * @@ -96,6 +100,8 @@ struct bus_type { const struct dev_pm_ops *pm; + struct iommu_ops *iommu_ops; + struct subsys_private *p; }; diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 6470cd87b4e..dca83d3405b 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -25,6 +25,7 @@ #define IOMMU_WRITE (2) #define IOMMU_CACHE (4) /* DMA cache coherency */ +struct bus_type; struct device; struct iommu_domain { @@ -52,6 +53,7 @@ struct iommu_ops { }; extern void register_iommu(struct iommu_ops *ops); +extern int bus_set_iommu(struct bus_type *bus, struct iommu_ops *ops); extern bool iommu_found(void); extern struct iommu_domain *iommu_domain_alloc(void); extern void iommu_domain_free(struct iommu_domain *domain); -- cgit v1.2.3 From 905d66c1e5dc8149e111f04a32bb193f25da1d53 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Tue, 6 Sep 2011 16:03:26 +0200 Subject: iommu/core: Add bus_type parameter to iommu_domain_alloc This is necessary to store a pointer to the bus-specific iommu_ops in the iommu-domain structure. It will be used later to call into bus-specific iommu-ops. Signed-off-by: Joerg Roedel --- include/linux/iommu.h | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/include/linux/iommu.h b/include/linux/iommu.h index dca83d3405b..c78d068930b 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -25,10 +25,12 @@ #define IOMMU_WRITE (2) #define IOMMU_CACHE (4) /* DMA cache coherency */ +struct iommu_ops; struct bus_type; struct device; struct iommu_domain { + struct iommu_ops *ops; void *priv; }; @@ -55,7 +57,7 @@ struct iommu_ops { extern void register_iommu(struct iommu_ops *ops); extern int bus_set_iommu(struct bus_type *bus, struct iommu_ops *ops); extern bool iommu_found(void); -extern struct iommu_domain *iommu_domain_alloc(void); +extern struct iommu_domain *iommu_domain_alloc(struct bus_type *bus); extern void iommu_domain_free(struct iommu_domain *domain); extern int iommu_attach_device(struct iommu_domain *domain, struct device *dev); @@ -79,7 +81,7 @@ static inline bool iommu_found(void) return false; } -static inline struct iommu_domain *iommu_domain_alloc(void) +static inline struct iommu_domain *iommu_domain_alloc(struct bus_type *bus) { return NULL; } -- cgit v1.2.3 From a1b60c1cd913c5ccfb38c717ba0bd22622425fa7 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Tue, 6 Sep 2011 18:46:34 +0200 Subject: iommu/core: Convert iommu_found to iommu_present With per-bus iommu_ops the iommu_found function needs to work on a bus_type too. This patch adds a bus_type parameter to that function and converts all call-places. The function is also renamed to iommu_present because the function now checks if an iommu is present for a given bus and does not check for a global iommu anymore. Signed-off-by: Joerg Roedel --- include/linux/iommu.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/include/linux/iommu.h b/include/linux/iommu.h index c78d068930b..f56e559442a 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -56,7 +56,7 @@ struct iommu_ops { extern void register_iommu(struct iommu_ops *ops); extern int bus_set_iommu(struct bus_type *bus, struct iommu_ops *ops); -extern bool iommu_found(void); +extern bool iommu_present(struct bus_type *bus); extern struct iommu_domain *iommu_domain_alloc(struct bus_type *bus); extern void iommu_domain_free(struct iommu_domain *domain); extern int iommu_attach_device(struct iommu_domain *domain, @@ -76,7 +76,7 @@ extern int iommu_domain_has_cap(struct iommu_domain *domain, struct iommu_ops {}; -static inline bool iommu_found(void) +static inline bool iommu_present(struct bus_type *bus) { return false; } -- cgit v1.2.3 From 94441c3bd99287b9d84f148a08cc9a44675ec749 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Tue, 6 Sep 2011 18:58:54 +0200 Subject: iommu/core: Remove global iommu_ops and register_iommu With all IOMMU drivers being converted to bus_set_iommu the global iommu_ops are no longer required. The same is true for the deprecated register_iommu function. Signed-off-by: Joerg Roedel --- include/linux/iommu.h | 1 - 1 file changed, 1 deletion(-) (limited to 'include') diff --git a/include/linux/iommu.h b/include/linux/iommu.h index f56e559442a..609ebf6bbe0 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -54,7 +54,6 @@ struct iommu_ops { unsigned long cap); }; -extern void register_iommu(struct iommu_ops *ops); extern int bus_set_iommu(struct bus_type *bus, struct iommu_ops *ops); extern bool iommu_present(struct bus_type *bus); extern struct iommu_domain *iommu_domain_alloc(struct bus_type *bus); -- cgit v1.2.3