x86/msr: Drop 32-bit MSR interfaces
| From: | Juergen Gross <jgross-AT-suse.com> | |
| To: | linux-kernel-AT-vger.kernel.org, linux-pm-AT-vger.kernel.org, linux-edac-AT-vger.kernel.org, x86-AT-kernel.org, linux-acpi-AT-vger.kernel.org, kvm-AT-vger.kernel.org, linux-coco-AT-lists.linux.dev, linux-pci-AT-vger.kernel.org, virtualization-AT-lists.linux.dev, linux-ide-AT-vger.kernel.org, dri-devel-AT-lists.freedesktop.org, linux-fbdev-AT-vger.kernel.org, linux-crypto-AT-vger.kernel.org, linux-gpio-AT-vger.kernel.org, linux-hyperv-AT-vger.kernel.org, linux-hwmon-AT-vger.kernel.org, linux-perf-users-AT-vger.kernel.org, linux-mtd-AT-lists.infradead.org, platform-driver-x86-AT-vger.kernel.org | |
| Subject: | [PATCH 00/32] x86/msr: Drop 32-bit MSR interfaces | |
| Date: | Mon, 29 Jun 2026 08:04:51 +0200 | |
| Message-ID: | <20260629060526.3638272-1-jgross@suse.com> | |
| Cc: | Juergen Gross <jgross-AT-suse.com>, "Rafael J. Wysocki" <rafael-AT-kernel.org>, Daniel Lezcano <daniel.lezcano-AT-kernel.org>, Zhang Rui <rui.zhang-AT-intel.com>, Lukasz Luba <lukasz.luba-AT-arm.com>, Jason Baron <jbaron-AT-akamai.com>, Borislav Petkov <bp-AT-alien8.de>, Tony Luck <tony.luck-AT-intel.com>, Yazen Ghannam <yazen.ghannam-AT-amd.com>, Len Brown <lenb-AT-kernel.org>, Pavel Machek <pavel-AT-kernel.org>, Thomas Gleixner <tglx-AT-kernel.org>, Ingo Molnar <mingo-AT-redhat.com>, Dave Hansen <dave.hansen-AT-linux.intel.com>, "H. Peter Anvin" <hpa-AT-zytor.com>, Sean Christopherson <seanjc-AT-google.com>, Paolo Bonzini <pbonzini-AT-redhat.com>, Kiryl Shutsemau <kas-AT-kernel.org>, Rick Edgecombe <rick.p.edgecombe-AT-intel.com>, Pu Wen <puwen-AT-hygon.cn>, Bjorn Helgaas <bhelgaas-AT-google.com>, Ajay Kaher <ajay.kaher-AT-broadcom.com>, Alexey Makhalov <alexey.makhalov-AT-broadcom.com>, Broadcom internal kernel review list <bcm-kernel-feedback-list-AT-broadcom.com>, Viresh Kumar <viresh.kumar-AT-linaro.org>, Reinette Chatre <reinette.chatre-AT-intel.com>, Dave Martin <Dave.Martin-AT-arm.com>, James Morse <james.morse-AT-arm.com>, Babu Moger <babu.moger-AT-amd.com>, Tony W Wang-oc <TonyWWang-oc-AT-zhaoxin.com>, Damien Le Moal <dlemoal-AT-kernel.org>, Niklas Cassel <cassel-AT-kernel.org>, David Airlie <airlied-AT-redhat.com>, Helge Deller <deller-AT-gmx.de>, linux-geode-AT-lists.infradead.org, Olivia Mackall <olivia-AT-selenic.com>, Herbert Xu <herbert-AT-gondor.apana.org.au>, Linus Walleij <linusw-AT-kernel.org>, Bartosz Golaszewski <brgl-AT-kernel.org>, Arnd Bergmann <arnd-AT-arndb.de>, Greg Kroah-Hartman <gregkh-AT-linuxfoundation.org>, "K. Y. Srinivasan" <kys-AT-microsoft.com>, Haiyang Zhang <haiyangz-AT-microsoft.com>, Wei Liu <wei.liu-AT-kernel.org>, Dexuan Cui <decui-AT-microsoft.com>, Long Li <longli-AT-microsoft.com>, Guenter Roeck <linux-AT-roeck-us.net>, Peter Zijlstra <peterz-AT-infradead.org>, Arnaldo Carvalho de Melo <acme-AT-kernel.org>, Namhyung Kim <namhyung-AT-kernel.org>, Mark Rutland <mark.rutland-AT-arm.com>, Alexander Shishkin <alexander.shishkin-AT-linux.intel.com>, Jiri Olsa <jolsa-AT-kernel.org>, Ian Rogers <irogers-AT-google.com>, Adrian Hunter <adrian.hunter-AT-intel.com>, James Clark <james.clark-AT-linaro.org>, Josh Poimboeuf <jpoimboe-AT-kernel.org>, Pawan Gupta <pawan.kumar.gupta-AT-linux.intel.com>, Vitaly Kuznetsov <vkuznets-AT-redhat.com>, Andy Lutomirski <luto-AT-kernel.org>, Boris Ostrovsky <boris.ostrovsky-AT-oracle.com>, Huang Rui <ray.huang-AT-amd.com>, Mario Limonciello <mario.limonciello-AT-amd.com>, Perry Yuan <perry.yuan-AT-amd.com>, K Prateek Nayak <kprateek.nayak-AT-amd.com>, Srinivas Pandruvada <srinivas.pandruvada-AT-linux.intel.com>, Artem Bityutskiy <artem.bityutskiy-AT-linux.intel.com>, Artem Bityutskiy <dedekind1-AT-gmail.com>, Miquel Raynal <miquel.raynal-AT-bootlin.com>, Richard Weinberger <richard-AT-nod.at>, Vignesh Raghavendra <vigneshr-AT-ti.com>, Ashok Raj <ashok.raj.linux-AT-gmail.com>, Hans de Goede <hansg-AT-kernel.org>, Ilpo Järvinen <ilpo.jarvinen-AT-linux.intel.com>, Rajneesh Bhardwaj <irenic.rajneesh-AT-gmail.com>, David E Box <david.e.box-AT-intel.com>, xen-devel-AT-lists.xenproject.org | |
| Archive-link: | Article |
For accessing the MSR registers on the local CPU, there are 2 types of interfaces: the "modern" 64-bit ones (rdmsrq() etc.) and the 32-bit ones (rdmsr() etc.) which are using the upper and lower 32-bit halves of the 64-bit wide MSR register values. The 32-bit interfaces are not optimal for 3 reasons: - They are based on primitives using 64-bit sized values anyway. - Modern x86 CPUs have added support for MSR access instructions using an immediate value instead of a register for addressing the MSR, while the value is in a 64-bit register. - rdmsr() is a macro storing the upper and lower 32-bit halves in variables specified as macro parameters. This is obscuring variable assignment through a macro. Additionally rdmsrq() is mimicking this pattern by being a macro, too, with the target variable specified as a parameter as well. For those reasons drop the 32-bit interfaces for accessing the x86 MSR registers completely and only use the 64-bit variants. This allows to switch all "high-level" MSR access macros to inline functions in the end. This series will be used as the base for further reorganisation of the MSR access functions, especially for completely inlining the MSR access instructions even with paravirtualization being active. Note that most patches of this series are independent from each other. Only the patches removing a specific interface (patches 7, 15, 26 and 30) and the last two patches of the series depend on all previous patches. Based on kernel 7.2-rc1, tested with and without parvirtualization active, compile tested for x86 with 64- and 32-bit allyes and allno configs. Juergen Gross (32): thermal/intel: Stop using 32-bit MSR interfaces powercap: Stop using 32-bit MSR interfaces edac: Stop using 32-bit MSR interfaces acpi: Stop using 32-bit MSR interfaces x86/mtrr: Stop using 32-bit MSR interfaces x86/msr: Stop using 32-bit MSR interfaces in lib/msr-smp.c x86/msr: Remove wrmsr_safe() x86/mce: Stop using 32-bit MSR interfaces KVM/x86: Stop using 32-bit MSR interfaces x86/hygon: Stop using 32-bit MSR interfaces x86/pci: Stop using 32-bit MSR interfaces x86/amd: Stop using 32-bit MSR interfaces x86/featctl: Stop using 32-bit MSR interfaces x86/tsc: Stop using 32-bit MSR interfaces x86/msr: Remove rdmsr_safe() cpufreq: Stop using 32-bit MSR interfaces x86/resctrl: Stop using 32-bit MSR interfaces x86/apic: Stop using 32-bit MSR interfaces x86/cpu: Stop using 32-bit MSR interfaces drivers/ata: Stop using 32-bit MSR interfaces agp/nvidia: Stop using 32-bit MSR interfaces fbdev/geode: Stop using 32-bit MSR interfaces hw_random/via-rng: Stop using 32-bit MSR interfaces drivers/gpio: Stop using 32-bit MSR interfaces drivers/misc: Stop using 32-bit MSR interfaces x86/msr: Remove wrmsr() x86/hyperv: Stop using 32-bit MSR interfaces x86/olpc: Stop using 32-bit MSR interfaces hwmon: Stop using 32-bit MSR interfaces x86/msr: Remove rdmsr() treewide: convert rdmsrq() from a macro to an inline function x86/msr: Simplify some rdmsrq() use cases arch/x86/coco/sev/core.c | 2 +- arch/x86/events/amd/brs.c | 4 +- arch/x86/events/amd/core.c | 8 +- arch/x86/events/amd/ibs.c | 18 ++-- arch/x86/events/amd/lbr.c | 16 +-- arch/x86/events/amd/power.c | 8 +- arch/x86/events/amd/uncore.c | 4 +- arch/x86/events/core.c | 20 ++-- arch/x86/events/intel/core.c | 14 +-- arch/x86/events/intel/cstate.c | 5 +- arch/x86/events/intel/ds.c | 2 +- arch/x86/events/intel/knc.c | 10 +- arch/x86/events/intel/lbr.c | 25 ++--- arch/x86/events/intel/p4.c | 6 +- arch/x86/events/intel/p6.c | 4 +- arch/x86/events/intel/pt.c | 12 +-- arch/x86/events/intel/uncore.c | 6 +- arch/x86/events/intel/uncore_nhmex.c | 4 +- arch/x86/events/intel/uncore_snb.c | 2 +- arch/x86/events/intel/uncore_snbep.c | 6 +- arch/x86/events/msr.c | 2 +- arch/x86/events/perf_event.h | 6 +- arch/x86/events/rapl.c | 6 +- arch/x86/events/zhaoxin/core.c | 10 +- arch/x86/hyperv/hv_apic.c | 17 ++-- arch/x86/hyperv/hv_init.c | 26 ++--- arch/x86/hyperv/hv_spinlock.c | 2 +- arch/x86/include/asm/apic.h | 7 +- arch/x86/include/asm/debugreg.h | 6 +- arch/x86/include/asm/fsgsbase.h | 2 +- arch/x86/include/asm/kvm_host.h | 5 +- arch/x86/include/asm/msr.h | 39 +------- arch/x86/include/asm/paravirt.h | 26 +---- arch/x86/include/asm/resctrl.h | 5 +- arch/x86/kernel/acpi/sleep.c | 20 ++-- arch/x86/kernel/apic/apic.c | 45 ++++----- arch/x86/kernel/apic/apic_numachip.c | 6 +- arch/x86/kernel/cet.c | 2 +- arch/x86/kernel/cpu/amd.c | 42 ++++---- arch/x86/kernel/cpu/aperfmperf.c | 8 +- arch/x86/kernel/cpu/bugs.c | 12 +-- arch/x86/kernel/cpu/bus_lock.c | 8 +- arch/x86/kernel/cpu/centaur.c | 35 +++---- arch/x86/kernel/cpu/common.c | 22 +++-- arch/x86/kernel/cpu/feat_ctl.c | 27 +++--- arch/x86/kernel/cpu/hygon.c | 9 +- arch/x86/kernel/cpu/intel.c | 12 +-- arch/x86/kernel/cpu/intel_epb.c | 4 +- arch/x86/kernel/cpu/mce/amd.c | 89 ++++++++--------- arch/x86/kernel/cpu/mce/core.c | 10 +- arch/x86/kernel/cpu/mce/inject.c | 2 +- arch/x86/kernel/cpu/mce/intel.c | 18 ++-- arch/x86/kernel/cpu/mce/p5.c | 16 +-- arch/x86/kernel/cpu/mce/winchip.c | 10 +- arch/x86/kernel/cpu/microcode/intel.c | 2 +- arch/x86/kernel/cpu/mshyperv.c | 6 +- arch/x86/kernel/cpu/mtrr/amd.c | 36 ++++--- arch/x86/kernel/cpu/mtrr/centaur.c | 18 ++-- arch/x86/kernel/cpu/mtrr/cleanup.c | 18 ++-- arch/x86/kernel/cpu/mtrr/generic.c | 97 ++++++++++--------- arch/x86/kernel/cpu/mtrr/mtrr.c | 4 +- arch/x86/kernel/cpu/resctrl/core.c | 9 +- arch/x86/kernel/cpu/resctrl/monitor.c | 27 +++--- arch/x86/kernel/cpu/resctrl/pseudo_lock.c | 12 +-- arch/x86/kernel/cpu/resctrl/rdtgroup.c | 2 +- arch/x86/kernel/cpu/topology.c | 2 +- arch/x86/kernel/cpu/topology_amd.c | 4 +- arch/x86/kernel/cpu/transmeta.c | 9 +- arch/x86/kernel/cpu/tsx.c | 10 +- arch/x86/kernel/cpu/umwait.c | 2 +- arch/x86/kernel/cpu/zhaoxin.c | 12 +-- arch/x86/kernel/fpu/core.c | 2 +- arch/x86/kernel/hpet.c | 2 +- arch/x86/kernel/kvm.c | 2 +- arch/x86/kernel/mmconf-fam10h_64.c | 6 +- arch/x86/kernel/process.c | 4 +- arch/x86/kernel/process_64.c | 14 +-- arch/x86/kernel/shstk.c | 8 +- arch/x86/kernel/traps.c | 4 +- arch/x86/kernel/tsc.c | 8 +- arch/x86/kernel/tsc_msr.c | 15 +-- arch/x86/kernel/tsc_sync.c | 6 +- arch/x86/kvm/svm/pmu.c | 4 +- arch/x86/kvm/svm/svm.c | 4 +- arch/x86/kvm/vmx/nested.c | 4 +- arch/x86/kvm/vmx/pmu_intel.c | 8 +- arch/x86/kvm/vmx/sgx.c | 6 +- arch/x86/kvm/vmx/vmx.c | 54 ++++++----- arch/x86/kvm/x86.c | 12 +-- arch/x86/lib/insn-eval.c | 6 +- arch/x86/lib/msr-smp.c | 8 +- arch/x86/mm/pat/memtype.c | 2 +- arch/x86/pci/amd_bus.c | 8 +- arch/x86/pci/mmconfig-shared.c | 8 +- arch/x86/platform/olpc/olpc-xo1-rtc.c | 6 +- arch/x86/platform/olpc/olpc-xo1-sci.c | 11 ++- arch/x86/power/cpu.c | 10 +- arch/x86/realmode/init.c | 2 +- arch/x86/virt/hw.c | 8 +- arch/x86/virt/svm/sev.c | 18 ++-- arch/x86/virt/vmx/tdx/tdx.c | 8 +- arch/x86/xen/suspend.c | 2 +- drivers/acpi/processor_perflib.c | 11 ++- drivers/acpi/processor_throttling.c | 14 +-- drivers/ata/pata_cs5535.c | 20 ++-- drivers/ata/pata_cs5536.c | 17 ++-- drivers/char/agp/nvidia-agp.c | 32 +++--- drivers/char/hw_random/via-rng.c | 29 +++--- drivers/cpufreq/acpi-cpufreq.c | 24 ++--- drivers/cpufreq/amd-pstate.c | 4 +- drivers/cpufreq/e_powersaver.c | 52 +++++----- drivers/cpufreq/intel_pstate.c | 30 +++--- drivers/cpufreq/longhaul.c | 23 ++--- drivers/cpufreq/longrun.c | 78 ++++++++------- drivers/cpufreq/powernow-k6.c | 12 +-- drivers/cpufreq/powernow-k7.c | 10 +- drivers/cpufreq/powernow-k8.c | 67 ++++++------- drivers/cpufreq/speedstep-centrino.c | 16 +-- drivers/cpufreq/speedstep-lib.c | 63 ++++++------ drivers/edac/amd64_edac.c | 6 +- drivers/edac/ie31200_edac.c | 10 +- drivers/edac/mce_amd.c | 8 +- drivers/gpio/gpio-cs5535.c | 10 +- drivers/hv/mshv_vtl_main.c | 2 +- drivers/hwmon/hwmon-vid.c | 11 ++- drivers/idle/intel_idle.c | 26 ++--- drivers/misc/cs5535-mfgpt.c | 33 +++---- drivers/mtd/nand/raw/cs553x_nand.c | 6 +- drivers/platform/x86/intel/ifs/load.c | 10 +- drivers/platform/x86/intel/ifs/runtest.c | 8 +- drivers/platform/x86/intel/pmc/cnp.c | 2 +- .../intel/speed_select_if/isst_if_mbox_msr.c | 6 +- .../intel/speed_select_if/isst_tpmi_core.c | 2 +- drivers/platform/x86/intel_ips.c | 20 ++-- drivers/powercap/intel_rapl_common.c | 20 ++-- drivers/powercap/intel_rapl_msr.c | 2 +- drivers/thermal/intel/intel_hfi.c | 8 +- drivers/thermal/intel/intel_tcc.c | 10 +- drivers/thermal/intel/therm_throt.c | 74 +++++++------- drivers/thermal/intel/x86_pkg_temp_thermal.c | 32 +++--- drivers/video/fbdev/geode/display_gx.c | 8 +- drivers/video/fbdev/geode/gxfb_core.c | 2 +- drivers/video/fbdev/geode/lxfb_ops.c | 50 +++++----- drivers/video/fbdev/geode/suspend_gx.c | 24 ++--- drivers/video/fbdev/geode/video_gx.c | 8 +- include/linux/cs5535.h | 10 +- 146 files changed, 1044 insertions(+), 1128 deletions(-) -- 2.54.0