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| author | Kornel Duleba <mindal@semihalf.com> | 2021-11-23 08:13:56 +0000 |
|---|---|---|
| committer | Wojciech Macek <wma@FreeBSD.org> | 2021-11-25 08:53:40 +0000 |
| commit | 68cbe189fdd3c572476f8af9219a5d335f05b51a (patch) | |
| tree | 8a1565b5572e9625baff8cd8d6698f054727c1e2 | |
| parent | 37c03d4de3d2104336adbb67a9aa2aa681b6d042 (diff) | |
| download | src-68cbe189fdd3c572476f8af9219a5d335f05b51a.tar.gz src-68cbe189fdd3c572476f8af9219a5d335f05b51a.zip | |
pci: Don't try to read cfg registers of non-existing devices
Instead of returning 0xffs some controllers, such as Layerscape generate
an external exception when someone attempts to read any register
of config space of a non-existing device other than PCIR_VENDOR.
This causes a kernel panic.
Fix it by bailing during device enumeration if a device vendor register
returns invalid value. (0xffff)
Use this opportunity to replace some hardcoded values with a macro.
I believe that this change won't have any unintended side-effects since
it is safe to assume that vendor == 0xffff -> hdr_type == 0xffff.
Sponsored by: Alstom
Obtained from: Semihalf
Reviewed by: jhb
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D33059
| -rw-r--r-- | sys/dev/pci/pci.c | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/sys/dev/pci/pci.c b/sys/dev/pci/pci.c index 7493ae1727fb..ecef65477137 100644 --- a/sys/dev/pci/pci.c +++ b/sys/dev/pci/pci.c @@ -683,11 +683,12 @@ pci_read_device(device_t pcib, device_t bus, int d, int b, int s, int f) uint16_t vid, did; vid = REG(PCIR_VENDOR, 2); + if (vid == PCIV_INVALID) + return (NULL); + did = REG(PCIR_DEVICE, 2); - if (vid != 0xffff) - return (pci_fill_devinfo(pcib, bus, d, b, s, f, vid, did)); - return (NULL); + return (pci_fill_devinfo(pcib, bus, d, b, s, f, vid, did)); } struct pci_devinfo * @@ -4141,6 +4142,10 @@ pci_add_children(device_t dev, int domain, int busno) pcifunchigh = 0; f = 0; DELAY(1); + + /* If function 0 is not present, skip to the next slot. */ + if (REG(PCIR_VENDOR, 2) == PCIV_INVALID) + continue; hdrtype = REG(PCIR_HDRTYPE, 1); if ((hdrtype & PCIM_HDRTYPE) > PCI_MAXHDRTYPE) continue; @@ -4182,7 +4187,7 @@ pci_rescan_method(device_t dev) for (s = 0; s <= maxslots; s++) { /* If function 0 is not present, skip to the next slot. */ f = 0; - if (REG(PCIR_VENDOR, 2) == 0xffff) + if (REG(PCIR_VENDOR, 2) == PCIV_INVALID) continue; pcifunchigh = 0; hdrtype = REG(PCIR_HDRTYPE, 1); @@ -4191,7 +4196,7 @@ pci_rescan_method(device_t dev) if (hdrtype & PCIM_MFDEV) pcifunchigh = PCIB_MAXFUNCS(pcib); for (f = 0; f <= pcifunchigh; f++) { - if (REG(PCIR_VENDOR, 2) == 0xffff) + if (REG(PCIR_VENDOR, 2) == PCIV_INVALID) continue; /* |