Date: Thu, 8 Dec 2022 20:03:55 GMT From: Tom Jones <thj@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org Subject: git: 308d3d6be6da - stable/13 - acpi: Tell SMM we will handle CPPC notifications Message-ID: <202212082003.2B8K3tb2000457@gitrepo.freebsd.org>
next in thread | raw e-mail | index | archive | help
The branch stable/13 has been updated by thj: URL: https://cgit.FreeBSD.org/src/commit/?id=308d3d6be6da1df4a47e641b5e0cedeccea7b09f commit 308d3d6be6da1df4a47e641b5e0cedeccea7b09f Author: Tom Jones <thj@FreeBSD.org> AuthorDate: 2022-10-10 13:46:25 +0000 Commit: Tom Jones <thj@FreeBSD.org> CommitDate: 2022-12-08 20:02:39 +0000 acpi: Tell SMM we will handle CPPC notifications Buggy SMM implementations can hang while processing CPPC notifications. This leads to some laptops (notably Thinkpads) hanging when the hwpstate_intel driver is loaded. Tell the SMM that we will handle CPPC notifications as described in: - Intel® Processor Vendor-Specific ACPI - Intel® 64 and IA-32 Architectures Software Developer’s Manual CPPC events default to masked (disabled) so while we do not do any handling right now this does not seem to lead to any issues. This approach was found via this Linux Kernel patch: https://lkml.org/lkml/2016/3/17/563 PR: 253288 Reviewed by: imp, jhb Sponsored by: Modirum Sponsored by: Klara, Inc. Differential Revision: https://reviews.freebsd.org/D36699 (cherry picked from commit 67f2a563bfcad75c16536ca500b06ddc9306dfa0) (cherry picked from commit eee0f7aea42564fe005c74f004d63f8cc170ef59) (cherry picked from commit 15bd2f366d3e878f5a8bc1628368d59ef318af5f) --- sys/dev/acpica/acpi_cpu.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/sys/dev/acpica/acpi_cpu.c b/sys/dev/acpica/acpi_cpu.c index 3cff973ef212..3c160e1c5cdd 100644 --- a/sys/dev/acpica/acpi_cpu.c +++ b/sys/dev/acpica/acpi_cpu.c @@ -153,6 +153,9 @@ static struct sysctl_ctx_list cpu_sysctl_ctx; static struct sysctl_oid *cpu_sysctl_tree; static int cpu_cx_generic; static int cpu_cx_lowest_lim; +#if defined(__i386__) || defined(__amd64__) +static bool cppc_notify; +#endif static struct acpi_cpu_softc **cpu_softc; ACPI_SERIAL_DECL(cpu, "ACPI CPU"); @@ -379,6 +382,14 @@ acpi_cpu_attach(device_t dev) cpu_sysctl_tree = SYSCTL_ADD_NODE(&cpu_sysctl_ctx, SYSCTL_CHILDREN(acpi_sc->acpi_sysctl_tree), OID_AUTO, "cpu", CTLFLAG_RD | CTLFLAG_MPSAFE, 0, "node for CPU children"); + +#if defined(__i386__) || defined(__amd64__) + /* Add sysctl handler to control registering for CPPC notifications */ + cppc_notify = 1; + SYSCTL_ADD_BOOL(&cpu_sysctl_ctx, SYSCTL_CHILDREN(cpu_sysctl_tree), + OID_AUTO, "cppc_notify", CTLFLAG_RDTUN | CTLFLAG_MPSAFE, + &cppc_notify, 0, "Register for CPPC Notifications"); +#endif } /* @@ -397,6 +408,13 @@ acpi_cpu_attach(device_t dev) */ if (!acpi_disabled("mwait") && cpu_mwait_usable()) sc->cpu_features |= ACPI_CAP_SMP_C1_NATIVE | ACPI_CAP_SMP_C3_NATIVE; + + /* + * Work around a lingering SMM bug which leads to freezes when handling + * CPPC notifications. Tell the SMM we will handle any CPPC notifications. + */ + if ((cpu_power_eax & CPUTPM1_HWP_NOTIFICATION) && cppc_notify) + sc->cpu_features |= ACPI_CAP_INTR_CPPC; #endif if (devclass_get_drivers(acpi_cpu_devclass, &drivers, &drv_count) == 0) {
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?202212082003.2B8K3tb2000457>