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 <ohad@wizery.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
This commit is contained in:
Ohad Ben-Cohen 2011-09-27 07:36:40 -04:00 committed by Joerg Roedel
parent 30bd918c71
commit 0ed6d2d27b
2 changed files with 11 additions and 1 deletions

View File

@ -43,6 +43,12 @@ EXPORT_SYMBOL_GPL(iommu_found);
* iommu_set_fault_handler() - set a fault handler for an iommu domain
* @domain: iommu domain
* @handler: fault handler
*
* This function should be used by IOMMU users which want to be notified
* whenever an IOMMU fault happens.
*
* The fault handler itself should return 0 on success, and an appropriate
* error code otherwise.
*/
void iommu_set_fault_handler(struct iommu_domain *domain,
iommu_fault_handler_t handler)

View File

@ -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,