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

Solaris DDI-specific (Solaris 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(5) for descriptions of the following attributes:

See Also

attributes(5), power(9E)

Writing Device Drivers

PCI Bus Power Management Interface Specification Version 1.1

PCI Bus Specification Revision 2.1