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
  ...

1 files changed, 38 insertions, 15 deletions

diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 621ff0803b04..ae81a7191c1c 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -75,11 +75,36 @@ extern u16 __read_mostly tlb_lld_4m[NR_INFO];
 extern u16 __read_mostly tlb_lld_1g[NR_INFO];
 
 /*
- *  CPU type and hardware bug flags. Kept separately for each CPU.
- *  Members of this structure are referenced in head_32.S, so think twice
- *  before touching them. [mj]
+ * CPU type and hardware bug flags. Kept separately for each CPU.
  */
 
+struct cpuinfo_topology {
+	// Real APIC ID read from the local APIC
+	u32			apicid;
+	// The initial APIC ID provided by CPUID
+	u32			initial_apicid;
+
+	// Physical package ID
+	u32			pkg_id;
+
+	// Physical die ID on AMD, Relative on Intel
+	u32			die_id;
+
+	// Compute unit ID - AMD specific
+	u32			cu_id;
+
+	// Core ID relative to the package
+	u32			core_id;
+
+	// Logical ID mappings
+	u32			logical_pkg_id;
+	u32			logical_die_id;
+
+	// Cache level topology IDs
+	u32			llc_id;
+	u32			l2c_id;
+};
+
 struct cpuinfo_x86 {
 	__u8			x86;		/* CPU family */
 	__u8			x86_vendor;	/* CPU vendor */
@@ -96,7 +121,6 @@ struct cpuinfo_x86 {
 	__u8			x86_phys_bits;
 	/* CPUID returned core id bits: */
 	__u8			x86_coreid_bits;
-	__u8			cu_id;
 	/* Max extended CPUID function supported: */
 	__u32			extended_cpuid_level;
 	/* Maximum supported CPUID level, -1=no CPUID: */
@@ -112,6 +136,7 @@ struct cpuinfo_x86 {
 	};
 	char			x86_vendor_id[16];
 	char			x86_model_id[64];
+	struct cpuinfo_topology	topo;
 	/* in KB - valid for CPUS which support this call: */
 	unsigned int		x86_cache_size;
 	int			x86_cache_alignment;	/* In bytes */
@@ -125,19 +150,9 @@ struct cpuinfo_x86 {
 	u64			ppin;
 	/* cpuid returned max cores value: */
 	u16			x86_max_cores;
-	u16			apicid;
-	u16			initial_apicid;
 	u16			x86_clflush_size;
 	/* number of cores as seen by the OS: */
 	u16			booted_cores;
-	/* Physical processor id: */
-	u16			phys_proc_id;
-	/* Logical processor id: */
-	u16			logical_proc_id;
-	/* Core id: */
-	u16			cpu_core_id;
-	u16			cpu_die_id;
-	u16			logical_die_id;
 	/* Index into per_cpu list: */
 	u16			cpu_index;
 	/*  Is SMT active on this core? */
@@ -678,7 +693,15 @@ extern int set_tsc_mode(unsigned int val);
 
 DECLARE_PER_CPU(u64, msr_misc_features_shadow);
 
-extern u16 get_llc_id(unsigned int cpu);
+static inline u32 per_cpu_llc_id(unsigned int cpu)
+{
+	return per_cpu(cpu_info.topo.llc_id, cpu);
+}
+
+static inline u32 per_cpu_l2c_id(unsigned int cpu)
+{
+	return per_cpu(cpu_info.topo.l2c_id, cpu);
+}
 
 #ifdef CONFIG_CPU_SUP_AMD
 extern u32 amd_get_nodes_per_socket(void);