Merge branches 'amd/fixes', 'debug/dma-api', 'arm/omap', 'arm/msm', 'core', 'iommu...

[linux-block.git] / include / linux / iommu.h

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 9940319d6f9d3ab0d1442a5fa31a7db9be6dafa3..432acc4c054df1134dddb9be501de5c27d84d926 100644 (file)
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -25,15 +25,29 @@
 #define IOMMU_WRITE    (2)
 #define IOMMU_CACHE    (4) /* DMA cache coherency */
 
+struct iommu_ops;
+struct bus_type;
 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 {
+       struct iommu_ops *ops;
        void *priv;
+       iommu_fault_handler_t handler;
 };
 
 #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);
@@ -49,11 +63,9 @@ 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);
+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);
 extern void iommu_domain_free(struct iommu_domain *domain);
 extern int iommu_attach_device(struct iommu_domain *domain,
                               struct device *dev);
@@ -67,19 +79,58 @@ 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).
+ *
+ * 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 = -ENOSYS;
 
-#else /* CONFIG_IOMMU_API */
+       /*
+        * if upper layers showed interest and installed a fault handler,
+        * invoke it.
+        */
+       if (domain->handler)
+               ret = domain->handler(domain, dev, iova, flags);
 
-static inline void register_iommu(struct iommu_ops *ops)
-{
+       return ret;
 }
 
-static inline bool iommu_found(void)
+#else /* CONFIG_IOMMU_API */
+
+struct iommu_ops {};
+
+static inline bool iommu_present(struct bus_type *bus)
 {
        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;
 }
@@ -123,6 +174,11 @@ 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 */