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author | 2023-10-30 17:37:47 -1000 | |
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committer | 2023-10-30 17:37:47 -1000 | |
commit | eb55307e6716b1a02f7db05e27d60e8ca2289c03 (patch) | |
tree | 030b84b0a3286926f21cdc91f6f8a053516bd76c /kernel | |
parent | Merge tag 'x86-apic-2023-10-29-v2' of git://git.kernel.org/pub/scm/linux/kern... (diff) | |
parent | x86/apic, x86/hyperv: Use u32 in hv_snp_boot_ap() too (diff) | |
download | linux-eb55307e6716b1a02f7db05e27d60e8ca2289c03.tar.gz linux-eb55307e6716b1a02f7db05e27d60e8ca2289c03.tar.bz2 linux-eb55307e6716b1a02f7db05e27d60e8ca2289c03.zip |
Merge tag 'x86-core-2023-10-29-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 core updates from Thomas Gleixner:
- Limit the hardcoded topology quirk for Hygon CPUs to those which have
a model ID less than 4.
The newer models have the topology CPUID leaf 0xB correctly
implemented and are not affected.
- Make SMT control more robust against enumeration failures
SMT control was added to allow controlling SMT at boottime or
runtime. The primary purpose was to provide a simple mechanism to
disable SMT in the light of speculation attack vectors.
It turned out that the code is sensible to enumeration failures and
worked only by chance for XEN/PV. XEN/PV has no real APIC enumeration
which means the primary thread mask is not set up correctly. By
chance a XEN/PV boot ends up with smp_num_siblings == 2, which makes
the hotplug control stay at its default value "enabled". So the mask
is never evaluated.
The ongoing rework of the topology evaluation caused XEN/PV to end up
with smp_num_siblings == 1, which sets the SMT control to "not
supported" and the empty primary thread mask causes the hotplug core
to deny the bringup of the APS.
Make the decision logic more robust and take 'not supported' and 'not
implemented' into account for the decision whether a CPU should be
booted or not.
- Fake primary thread mask for XEN/PV
Pretend that all XEN/PV vCPUs are primary threads, which makes the
usage of the primary thread mask valid on XEN/PV. That is consistent
with because all of the topology information on XEN/PV is fake or
even non-existent.
- Encapsulate topology information in cpuinfo_x86
Move the randomly scattered topology data into a separate data
structure for readability and as a preparatory step for the topology
evaluation overhaul.
- Consolidate APIC ID data type to u32
It's fixed width hardware data and not randomly u16, int, unsigned
long or whatever developers decided to use.
- Cure the abuse of cpuinfo for persisting logical IDs.
Per CPU cpuinfo is used to persist the logical package and die IDs.
That's really not the right place simply because cpuinfo is subject
to be reinitialized when a CPU goes through an offline/online cycle.
Use separate per CPU data for the persisting to enable the further
topology management rework. It will be removed once the new topology
management is in place.
- Provide a debug interface for inspecting topology information
Useful in general and extremly helpful for validating the topology
management rework in terms of correctness or "bug" compatibility.
* tag 'x86-core-2023-10-29-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
x86/apic, x86/hyperv: Use u32 in hv_snp_boot_ap() too
x86/cpu: Provide debug interface
x86/cpu/topology: Cure the abuse of cpuinfo for persisting logical ids
x86/apic: Use u32 for wakeup_secondary_cpu[_64]()
x86/apic: Use u32 for [gs]et_apic_id()
x86/apic: Use u32 for phys_pkg_id()
x86/apic: Use u32 for cpu_present_to_apicid()
x86/apic: Use u32 for check_apicid_used()
x86/apic: Use u32 for APIC IDs in global data
x86/apic: Use BAD_APICID consistently
x86/cpu: Move cpu_l[l2]c_id into topology info
x86/cpu: Move logical package and die IDs into topology info
x86/cpu: Remove pointless evaluation of x86_coreid_bits
x86/cpu: Move cu_id into topology info
x86/cpu: Move cpu_core_id into topology info
hwmon: (fam15h_power) Use topology_core_id()
scsi: lpfc: Use topology_core_id()
x86/cpu: Move cpu_die_id into topology info
x86/cpu: Move phys_proc_id into topology info
x86/cpu: Encapsulate topology information in cpuinfo_x86
...
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/cpu.c | 18 |
1 files changed, 13 insertions, 5 deletions
diff --git a/kernel/cpu.c b/kernel/cpu.c index 94430ea8b4a5..303cb0591b4b 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -659,11 +659,19 @@ static inline bool cpu_smt_thread_allowed(unsigned int cpu) #endif } -static inline bool cpu_smt_allowed(unsigned int cpu) +static inline bool cpu_bootable(unsigned int cpu) { if (cpu_smt_control == CPU_SMT_ENABLED && cpu_smt_thread_allowed(cpu)) return true; + /* All CPUs are bootable if controls are not configured */ + if (cpu_smt_control == CPU_SMT_NOT_IMPLEMENTED) + return true; + + /* All CPUs are bootable if CPU is not SMT capable */ + if (cpu_smt_control == CPU_SMT_NOT_SUPPORTED) + return true; + if (topology_is_primary_thread(cpu)) return true; @@ -685,7 +693,7 @@ bool cpu_smt_possible(void) EXPORT_SYMBOL_GPL(cpu_smt_possible); #else -static inline bool cpu_smt_allowed(unsigned int cpu) { return true; } +static inline bool cpu_bootable(unsigned int cpu) { return true; } #endif static inline enum cpuhp_state @@ -788,10 +796,10 @@ static int bringup_wait_for_ap_online(unsigned int cpu) * SMT soft disabling on X86 requires to bring the CPU out of the * BIOS 'wait for SIPI' state in order to set the CR4.MCE bit. The * CPU marked itself as booted_once in notify_cpu_starting() so the - * cpu_smt_allowed() check will now return false if this is not the + * cpu_bootable() check will now return false if this is not the * primary sibling. */ - if (!cpu_smt_allowed(cpu)) + if (!cpu_bootable(cpu)) return -ECANCELED; return 0; } @@ -1744,7 +1752,7 @@ static int cpu_up(unsigned int cpu, enum cpuhp_state target) err = -EBUSY; goto out; } - if (!cpu_smt_allowed(cpu)) { + if (!cpu_bootable(cpu)) { err = -EPERM; goto out; } |