xref: /openbmc/qemu/hw/pci/slotid_cap.c (revision a9ded601)
1 #include "qemu/osdep.h"
2 #include "hw/pci/slotid_cap.h"
3 #include "hw/pci/pci.h"
4 #include "qemu/error-report.h"
5 
6 #define SLOTID_CAP_LENGTH 4
7 #define SLOTID_NSLOTS_SHIFT ctz32(PCI_SID_ESR_NSLOTS)
8 
9 int slotid_cap_init(PCIDevice *d, int nslots,
10                     uint8_t chassis,
11                     unsigned offset)
12 {
13     int cap;
14     if (!chassis) {
15         error_report("Bridge chassis not specified. Each bridge is required "
16                      "to be assigned a unique chassis id > 0.");
17         return -EINVAL;
18     }
19     if (nslots < 0 || nslots > (PCI_SID_ESR_NSLOTS >> SLOTID_NSLOTS_SHIFT)) {
20         /* TODO: error report? */
21         return -EINVAL;
22     }
23 
24     cap = pci_add_capability(d, PCI_CAP_ID_SLOTID, offset, SLOTID_CAP_LENGTH);
25     if (cap < 0) {
26         return cap;
27     }
28     /* We make each chassis unique, this way each bridge is First in Chassis */
29     d->config[cap + PCI_SID_ESR] = PCI_SID_ESR_FIC |
30         (nslots << SLOTID_NSLOTS_SHIFT);
31     d->cmask[cap + PCI_SID_ESR] = 0xff;
32     d->config[cap + PCI_SID_CHASSIS_NR] = chassis;
33     /* Note: Chassis number register is non-volatile,
34        so we don't reset it. */
35     /* TODO: store in eeprom? */
36     d->wmask[cap + PCI_SID_CHASSIS_NR] = 0xff;
37 
38     d->cap_present |= QEMU_PCI_CAP_SLOTID;
39     return 0;
40 }
41 
42 void slotid_cap_cleanup(PCIDevice *d)
43 {
44     /* TODO: cleanup config space? */
45     d->cap_present &= ~QEMU_PCI_CAP_SLOTID;
46 }
47