NAME

pci_save_config_regs, pci_restore_config_regs - save and restore the PCI configuration registers

SYNOPSIS

#include <sys/ddi.h>
#include <sys/sunddi.h>
int pci_save_config_regs(dev_info_t *dip);

int pci_restore_config_regs(dev_info_t *dip);

INTERFACE LEVEL

illumos DDI-specific (illumos DDI).

ARGUMENTS

dip

Pointer to the device's dev_info structure.

DESCRIPTION

pci_save_config_regs() saves the current configuration registers on persistent system memory. pci_restore_config_regs() restores configuration registers previously saved by pci_save_config_regs().

pci_save_config_regs() should be called by the driver's power() entry point before powering a device off (to PCI state D3). Likewise, pci_restore_config_regs() should be called after powering a device on (from PCI state D3), but before accessing the device. See power(9E).

RETURN VALUES

pci_save_config_regs() and pci_restore_config_regs() return:

DDI_SUCCESS

Operation completed successfully.

DDI_FAILURE

Operation failed to complete successfully.

CONTEXT

Both these functions can be called from user or kernel context.

EXAMPLES

Example 1 Invoking the save and restore functions

static int
xx_power(dev_info_t *dip, int component, int level) {


   struct xx *xx;


   int rval = DDI_SUCCESS;


   xx = ddi_get_soft_state(xx_softstate, ddi_get_instance(dip));


   if (xx == NULL) {


       return (DDI_FAILURE);


   }


   mutex_enter(&xx−>x_mutex);


   switch (level) {


   case PM_LEVEL_D0:


       XX_POWER_ON(xx);


       if (pci_restore_config_regs(dip) == DDI_FAILURE) {


           /*


            * appropriate error path handling here


            */


           ...


           rval = DDI_FAILURE;


           }


       break;


   case PM_LEVEL_D3:


       if (pci_save_config_regs(dip) == DDI_FAILURE) {


            /*


             * appropriate error path handling here


             */


            ...


            rval = DDI_FAILURE;


            }


        else {


            XX_POWER_OFF(xx);


        }


        break;


    default:


          rval = DDI_FAILURE;


          break;


    }


    mutex_exit(&xx−>x_mutex);


    return (rval);
}

ATTRIBUTES

See attributes(7) for descriptions of the following attributes:

ATTRIBUTE TYPE	ATTRIBUTE VALUE
Interface Stability	Committed