Date: Fri, 01 May 2026 00:08:25 +0000 From: Adrian Chadd <adrian@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: 6a0610cb5018 - main - powerpc/pic: fix the openpic CPU logic to work on powermac Message-ID: <69f3eef9.32696.499d8cb1@gitrepo.freebsd.org>
index | next in thread | raw e-mail
The branch main has been updated by adrian: URL: https://cgit.FreeBSD.org/src/commit/?id=6a0610cb50181d1797d1a8c5d60ad76c666a625e commit 6a0610cb50181d1797d1a8c5d60ad76c666a625e Author: Adrian Chadd <adrian@FreeBSD.org> AuthorDate: 2026-05-01 00:07:48 +0000 Commit: Adrian Chadd <adrian@FreeBSD.org> CommitDate: 2026-05-01 00:07:48 +0000 powerpc/pic: fix the openpic CPU logic to work on powermac Earlier work (40bcad56f - powerpc/pic: Add a PIC_AP_INIT() to set up AP PIC info) broke booting my dual G5 powermac. After much digging, jhibbits@ and I discovered that the openpic implementation for the memory/bus controller used in the G5 CPUs doesn't implement /all/ of the openpic specification. Notably it sticks the WHOAMI register in a different location. This is reading 0x0 back for all the PICs which is .. very not great. So to restore the previous behaviour, use a quick for now that jhibbits@ can set appropriately to trust WHOAMI. I've tested this on my dual G5 PPC and it boots/runs fine. Fixes: 40bcad56f Reviewed by: jhibbits Differential Revision: https://reviews.freebsd.org/D56751 --- sys/powerpc/include/openpicvar.h | 1 + sys/powerpc/ofw/openpic_ofw.c | 1 + sys/powerpc/powerpc/openpic.c | 17 ++++++++++++++++- 3 files changed, 18 insertions(+), 1 deletion(-) diff --git a/sys/powerpc/include/openpicvar.h b/sys/powerpc/include/openpicvar.h index 4f086f809f08..2aca4b38e845 100644 --- a/sys/powerpc/include/openpicvar.h +++ b/sys/powerpc/include/openpicvar.h @@ -36,6 +36,7 @@ #define OPENPIC_QUIRK_SINGLE_BIND 1 /* Bind interrupts to only 1 CPU */ #define OPENPIC_QUIRK_HIDDEN_IRQS 2 /* May have IRQs beyond FRR[NIRQ] */ +#define OPENPIC_QUIRK_WHOAMI_WORKS 4 /* WHOAMI register is present */ /* Names match the macros in openpicreg.h. */ struct openpic_timer { diff --git a/sys/powerpc/ofw/openpic_ofw.c b/sys/powerpc/ofw/openpic_ofw.c index 4083e9eba749..48e2038f2f53 100644 --- a/sys/powerpc/ofw/openpic_ofw.c +++ b/sys/powerpc/ofw/openpic_ofw.c @@ -125,6 +125,7 @@ openpic_ofw_attach(device_t dev) if (ofw_bus_is_compatible(dev, "fsl,mpic")) { sc->sc_quirks = OPENPIC_QUIRK_SINGLE_BIND; sc->sc_quirks |= OPENPIC_QUIRK_HIDDEN_IRQS; + sc->sc_quirks |= OPENPIC_QUIRK_WHOAMI_WORKS; } return (openpic_common_attach(dev, xref)); diff --git a/sys/powerpc/powerpc/openpic.c b/sys/powerpc/powerpc/openpic.c index 3cb4c544a91a..d0c0cc59afe5 100644 --- a/sys/powerpc/powerpc/openpic.c +++ b/sys/powerpc/powerpc/openpic.c @@ -469,8 +469,23 @@ openpic_ap_init(device_t dev) if (dev != root_pic) return; + /* + * Not everything implements the full OpenPIC specification. + * + * Notably the CPC945 Bridge and Memory Controller User Manual, which + * is in the PPC 970 (ie Apple G5) CPUs, calls out a set of + * deviations from the specification. Thus we can't just assume + * WHOAMI is available everywhere. + * + * See 9.5.3.3 - Deviations from the OpenPIC specification. + * Notably - the WhoAmI register is actually 0xF8000050 for all CPUs. + */ + sc = device_get_softc(dev); - PCPU_SET(pic, bus_read_4(sc->sc_memr, OPENPIC_WHOAMI)); + if (sc->sc_quirks & OPENPIC_QUIRK_WHOAMI_WORKS) + PCPU_SET(pic, bus_read_4(sc->sc_memr, OPENPIC_WHOAMI)); + else + PCPU_SET(pic, PCPU_GET(cpuid)); } static device_method_t openpic_methods[] = {home | help
Want to link to this message? Use this
URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?69f3eef9.32696.499d8cb1>