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pci_save_config_regs, pci_restore_config_regs - save and restore the PCI configuration registers

#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);

illumos DDI-specific (illumos DDI). dip 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).

pci_save_config_regs() and pci_restore_config_regs() return: DDI_SUCCESS DDI_FAILURE Both these functions can be called from user or kernel context. 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);
}

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

ATTRIBUTE TYPE ATTRIBUTE VALUE

Interface Stability Committed

attributes(5), power(9E)

Writing Device Drivers

PCI Bus Power Management Interface Specification Version 1.1

PCI Bus Specification Revision 2.1