DDI_FM_ACC_ERR_GET(9F) Kernel Functions for Drivers DDI_FM_ACC_ERR_GET(9F)

ddi_fm_acc_err_get, ddi_fm_dma_err_get - get the error status for an access or DMA handle

#include <sys/ddifm.h>
void ddi_fm_acc_err_get(ddi_acc_handle_t acc_handle,
     ddi_fm_error_t *error_status, int version);

void ddi_fm_dma_err_get(ddi_dma_handle_t dma_handle,
     ddi_fm_error_t *error_status, int version);

illumos DDI specific (illumos DDI)

Data access handle obtained from a previous call to ddi_regs_map_setup(9F), ddi_dma_mem_alloc(9F), or to a similar function.


DMA handle obtained from a previous call to ddi_dma_mem_alloc(9F) or one of its derivatives.


Pointer to where the error status for the access or DMA handle should be returned.


Version number of ddi_fm_error_t. The driver should always set this to DDI_FME_VERSION.

The ddi_fm_dma_err_get() and ddi_fm_acc_err_get() functions return the error status for a DMA or access handle respectively. If a fault has occurred that affects the resource mapped by the supplied handle, the supplied error_status structure is updated to reflect error information captured during error handling by a bus or other device driver in the I/O data path.

If an error is indicated for an access handle, the driver might no longer be able to access the mapped registers or memory using programmed I/O through the handle. Typically, this might occur after the device has failed to respond to an I/O access - in the case of a bus error, for instance, or a timeout. The effect of programmed I/O access made at the time of a fault is undefined. Read access via ddi_get8(9F), for example, can return random values, while write access via ddi_put8(9F) might or might not have an effect. It is possible, however, that the error might be transient. In that case, the driver can attempt to recover by calling ddi_fm_acc_err_clear(), resetting the device to return it to a known state, then retrying any potentially failed transactions.

If an error is indicated for a DMA handle, it implies that an error has been detected that has or will affect DMA transactions between the device and the memory currently bound to the handle - or the memory most recently bound, if the handle is currently unbound. Possible causes include the failure of a component in the DMA data path or an attempt by the device to make an invalid DMA access. The contents of any memory currently or previously bound to the handle should be considered indeterminate. The driver might be able to continue by freeing memory that is bound to the handle back to the system, resetting the device to return it to a known state, then retrying any potentially failed transactions.

If the driver is unable to recover, the operating state should be changed by a call to ddi_fm_service_impact() that specifies DDI_SERVICE_LOST for the impacted device instance. If the recovery and retry succeed, a call should still be made to ddi_fm_service_impact() but DDI_SERVICE_UNAFFECTED should be specified.

The ddi_fm_acc_err_get() and ddi_fm_dma_err_get() functions can be called from user, kernel, or high-level interrupt context.

See attributes(5) for descriptions of the following attributes:

Interface Stability Committed

attributes(5), ddi_dma_mem_alloc(9F), ddi_fm_acc_err_clear(9F), ddi_fm_service_impact(9F), ddi_get8(9F), ddi_put8(9F), ddi_regs_map_setup(9F), ddi_fm_error(9S),

Writing Device Drivers

March 27, 2016 OmniOS