diff options
author | jhb <jhb@FreeBSD.org> | 2009-06-09 13:44:17 +0000 |
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committer | jhb <jhb@FreeBSD.org> | 2009-06-09 13:44:17 +0000 |
commit | 7e92c698d93e930bd9f98da57fa435a205f23986 (patch) | |
tree | 41880645f901f36627ecfbabd535150c412541f5 | |
parent | 4270aed4c5c82e67773d38568f637558031d3e7b (diff) | |
download | FreeBSD-src-7e92c698d93e930bd9f98da57fa435a205f23986.zip FreeBSD-src-7e92c698d93e930bd9f98da57fa435a205f23986.tar.gz |
Rework the _BBN handling for Host-PCI bridges. Previously we only trusted
a _BBN value of 0 if it was for the first bridge encountered since some
older systems returned _BBN of 0 for all bridges. However, some newer
systems enumerate bridges with non-zero _BBN before bus 0 which is
perfectly valid. Handle both cases by trusting the first bridge that has
a _BBN of 0 and falling back to reading from non-standard config registers
only for subsequent bridges with a _BBN of 0. We also only perform this
check for segment (domain) 0. We assume that _BBN is always correct
for segments other than 0.
Tested by: Josef Moellers josef.moellers at fujitsu
MFC after: 1 week
-rw-r--r-- | sys/dev/acpica/acpi_pcib_acpi.c | 43 |
1 files changed, 25 insertions, 18 deletions
diff --git a/sys/dev/acpica/acpi_pcib_acpi.c b/sys/dev/acpica/acpi_pcib_acpi.c index d9827ab..7f5b8b7 100644 --- a/sys/dev/acpica/acpi_pcib_acpi.c +++ b/sys/dev/acpica/acpi_pcib_acpi.c @@ -148,6 +148,7 @@ acpi_pcib_acpi_attach(device_t dev) { struct acpi_hpcib_softc *sc; ACPI_STATUS status; + static int bus0_seen = 0; u_int addr, slot, func, busok; uint8_t busno; @@ -158,6 +159,21 @@ acpi_pcib_acpi_attach(device_t dev) sc->ap_handle = acpi_get_handle(dev); /* + * Get our segment number by evaluating _SEG + * It's OK for this to not exist. + */ + status = acpi_GetInteger(sc->ap_handle, "_SEG", &sc->ap_segment); + if (ACPI_FAILURE(status)) { + if (status != AE_NOT_FOUND) { + device_printf(dev, "could not evaluate _SEG - %s\n", + AcpiFormatException(status)); + return_VALUE (ENXIO); + } + /* If it's not found, assume 0. */ + sc->ap_segment = 0; + } + + /* * Get our base bus number by evaluating _BBN. * If this doesn't work, we assume we're bus number 0. * @@ -171,8 +187,10 @@ acpi_pcib_acpi_attach(device_t dev) * XXX invoke _REG on this for the PCI config space address space? * XXX It seems many BIOS's with multiple Host-PCI bridges do not set * _BBN correctly. They set _BBN to zero for all bridges. Thus, - * if _BBN is zero and pcib0 already exists, we try to read our + * if _BBN is zero and PCI bus 0 already exists, we try to read our * bus number from the configuration registers at address _ADR. + * We only do this for domain/segment 0 in the hopes that this is + * only needed for old single-domain machines. */ status = acpi_GetInteger(sc->ap_handle, "_BBN", &sc->ap_bus); if (ACPI_FAILURE(status)) { @@ -187,11 +205,11 @@ acpi_pcib_acpi_attach(device_t dev) } /* - * If the bus is zero and pcib0 already exists, read the bus number - * via PCI config space. + * If this is segment 0, the bus is zero, and PCI bus 0 already + * exists, read the bus number via PCI config space. */ busok = 1; - if (sc->ap_bus == 0 && devclass_get_device(pcib_devclass, 0) != dev) { + if (sc->ap_segment == 0 && sc->ap_bus == 0 && bus0_seen) { busok = 0; status = acpi_GetInteger(sc->ap_handle, "_ADR", &addr); if (ACPI_FAILURE(status)) { @@ -228,20 +246,9 @@ acpi_pcib_acpi_attach(device_t dev) device_printf(dev, "trying bus number %d\n", sc->ap_bus); } - /* - * Get our segment number by evaluating _SEG - * It's OK for this to not exist. - */ - status = acpi_GetInteger(sc->ap_handle, "_SEG", &sc->ap_segment); - if (ACPI_FAILURE(status)) { - if (status != AE_NOT_FOUND) { - device_printf(dev, "could not evaluate _SEG - %s\n", - AcpiFormatException(status)); - return_VALUE (ENXIO); - } - /* If it's not found, assume 0. */ - sc->ap_segment = 0; - } + /* If this is bus 0 on segment 0, note that it has been seen already. */ + if (sc->ap_segment == 0 && sc->ap_bus == 0) + bus0_seen = 1; return (acpi_pcib_attach(dev, &sc->ap_prt, sc->ap_bus)); } |