xref: /illumos-gate/usr/src/man/man9f/pci_save_config_regs.9f (revision bbf215553c7233fbab8a0afdf1fac74c44781867)
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PCI_SAVE_CONFIG_REGS 9F "Jun 02, 2000"
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
SEE ALSO
attributes (7), power (9E)

Writing Device Drivers

PCI Bus Power Management Interface Specification Version 1.1

PCI Bus Specification Revision 2.1