xref: /openbmc/qemu/hw/pci/slotid_cap.c (revision d0bf492f)
1 #include "qemu/osdep.h"
2 #include "hw/pci/slotid_cap.h"
3 #include "hw/pci/pci_device.h"
4 #include "qemu/error-report.h"
5 #include "qapi/error.h"
6 
7 #define SLOTID_CAP_LENGTH 4
8 #define SLOTID_NSLOTS_SHIFT ctz32(PCI_SID_ESR_NSLOTS)
9 
10 int slotid_cap_init(PCIDevice *d, int nslots,
11                     uint8_t chassis,
12                     unsigned offset,
13                     Error **errp)
14 {
15     int cap;
16 
17     if (!chassis) {
18         error_setg(errp, "Bridge chassis not specified. Each bridge is required"
19                    " to be assigned a unique chassis id > 0.");
20         return -EINVAL;
21     }
22     if (nslots < 0 || nslots > (PCI_SID_ESR_NSLOTS >> SLOTID_NSLOTS_SHIFT)) {
23         /* TODO: error report? */
24         return -EINVAL;
25     }
26 
27     cap = pci_add_capability(d, PCI_CAP_ID_SLOTID, offset,
28                              SLOTID_CAP_LENGTH, errp);
29     if (cap < 0) {
30         return cap;
31     }
32     /* We make each chassis unique, this way each bridge is First in Chassis */
33     d->config[cap + PCI_SID_ESR] = PCI_SID_ESR_FIC |
34         (nslots << SLOTID_NSLOTS_SHIFT);
35     d->cmask[cap + PCI_SID_ESR] = 0xff;
36     d->config[cap + PCI_SID_CHASSIS_NR] = chassis;
37     /* Note: Chassis number register is non-volatile,
38        so we don't reset it. */
39     /* TODO: store in eeprom? */
40     d->wmask[cap + PCI_SID_CHASSIS_NR] = 0xff;
41 
42     d->cap_present |= QEMU_PCI_CAP_SLOTID;
43     return 0;
44 }
45 
46 void slotid_cap_cleanup(PCIDevice *d)
47 {
48     /* TODO: cleanup config space? */
49     d->cap_present &= ~QEMU_PCI_CAP_SLOTID;
50 }
51