From f193ea20eddc6cef84cba54cf1a647204ee6a86b Mon Sep 17 00:00:00 2001 From: Noah Goldstein Date: Wed, 7 Jun 2023 13:18:02 -0500 Subject: [PATCH] x86: Refactor Intel `init_cpu_features` Content-type: text/plain; charset=UTF-8 This patch should have no affect on existing functionality. The current code, which has a single switch for model detection and setting prefered features, is difficult to follow/extend. The cases use magic numbers and many microarchitectures are missing. This makes it difficult to reason about what is implemented so far and/or how/where to add support for new features. This patch splits the model detection and preference setting stages so that CPU preferences can be set based on a complete list of available microarchitectures, rather than based on model magic numbers. Reviewed-by: DJ Delorie --- sysdeps/x86/cpu-features.c | 390 +++++++++++++++++++++++++++++-------- 1 file changed, 309 insertions(+), 81 deletions(-) diff --git a/sysdeps/x86/cpu-features.c b/sysdeps/x86/cpu-features.c index 0a99efdb28..d52a718e92 100644 --- a/sysdeps/x86/cpu-features.c +++ b/sysdeps/x86/cpu-features.c @@ -417,6 +417,216 @@ _Static_assert (((index_arch_Fast_Unaligned_Load == index_arch_Fast_Copy_Backward)), "Incorrect index_arch_Fast_Unaligned_Load"); + +/* Intel Family-6 microarch list. */ +enum +{ + /* Atom processors. */ + INTEL_ATOM_BONNELL, + INTEL_ATOM_SILVERMONT, + INTEL_ATOM_AIRMONT, + INTEL_ATOM_GOLDMONT, + INTEL_ATOM_GOLDMONT_PLUS, + INTEL_ATOM_SIERRAFOREST, + INTEL_ATOM_GRANDRIDGE, + INTEL_ATOM_TREMONT, + + /* Bigcore processors. */ + INTEL_BIGCORE_MEROM, + INTEL_BIGCORE_PENRYN, + INTEL_BIGCORE_DUNNINGTON, + INTEL_BIGCORE_NEHALEM, + INTEL_BIGCORE_WESTMERE, + INTEL_BIGCORE_SANDYBRIDGE, + INTEL_BIGCORE_IVYBRIDGE, + INTEL_BIGCORE_HASWELL, + INTEL_BIGCORE_BROADWELL, + INTEL_BIGCORE_SKYLAKE, + INTEL_BIGCORE_KABYLAKE, + INTEL_BIGCORE_COMETLAKE, + INTEL_BIGCORE_SKYLAKE_AVX512, + INTEL_BIGCORE_CANNONLAKE, + INTEL_BIGCORE_ICELAKE, + INTEL_BIGCORE_TIGERLAKE, + INTEL_BIGCORE_ROCKETLAKE, + INTEL_BIGCORE_SAPPHIRERAPIDS, + INTEL_BIGCORE_RAPTORLAKE, + INTEL_BIGCORE_EMERALDRAPIDS, + INTEL_BIGCORE_METEORLAKE, + INTEL_BIGCORE_LUNARLAKE, + INTEL_BIGCORE_ARROWLAKE, + INTEL_BIGCORE_GRANITERAPIDS, + + /* Mixed (bigcore + atom SOC). */ + INTEL_MIXED_LAKEFIELD, + INTEL_MIXED_ALDERLAKE, + + /* KNL. */ + INTEL_KNIGHTS_MILL, + INTEL_KNIGHTS_LANDING, + + /* Unknown. */ + INTEL_UNKNOWN, +}; + +static unsigned int +intel_get_fam6_microarch (unsigned int model, + __attribute__ ((unused)) unsigned int stepping) +{ + switch (model) + { + case 0x1C: + case 0x26: + return INTEL_ATOM_BONNELL; + case 0x27: + case 0x35: + case 0x36: + /* Really Saltwell, but Saltwell is just a die shrink of Bonnell + (microarchitecturally identical). */ + return INTEL_ATOM_BONNELL; + case 0x37: + case 0x4A: + case 0x4D: + case 0x5D: + return INTEL_ATOM_SILVERMONT; + case 0x4C: + case 0x5A: + case 0x75: + return INTEL_ATOM_AIRMONT; + case 0x5C: + case 0x5F: + return INTEL_ATOM_GOLDMONT; + case 0x7A: + return INTEL_ATOM_GOLDMONT_PLUS; + case 0xAF: + return INTEL_ATOM_SIERRAFOREST; + case 0xB6: + return INTEL_ATOM_GRANDRIDGE; + case 0x86: + case 0x96: + case 0x9C: + return INTEL_ATOM_TREMONT; + case 0x0F: + case 0x16: + return INTEL_BIGCORE_MEROM; + case 0x17: + return INTEL_BIGCORE_PENRYN; + case 0x1D: + return INTEL_BIGCORE_DUNNINGTON; + case 0x1A: + case 0x1E: + case 0x1F: + case 0x2E: + return INTEL_BIGCORE_NEHALEM; + case 0x25: + case 0x2C: + case 0x2F: + return INTEL_BIGCORE_WESTMERE; + case 0x2A: + case 0x2D: + return INTEL_BIGCORE_SANDYBRIDGE; + case 0x3A: + case 0x3E: + return INTEL_BIGCORE_IVYBRIDGE; + case 0x3C: + case 0x3F: + case 0x45: + case 0x46: + return INTEL_BIGCORE_HASWELL; + case 0x3D: + case 0x47: + case 0x4F: + case 0x56: + return INTEL_BIGCORE_BROADWELL; + case 0x4E: + case 0x5E: + return INTEL_BIGCORE_SKYLAKE; + case 0x8E: + /* + Stepping = {9} + -> Amberlake + Stepping = {10} + -> Coffeelake + Stepping = {11, 12} + -> Whiskeylake + else + -> Kabylake + + All of these are derivatives of Kabylake (Skylake client). + */ + return INTEL_BIGCORE_KABYLAKE; + case 0x9E: + /* + Stepping = {10, 11, 12, 13} + -> Coffeelake + else + -> Kabylake + + Coffeelake is a derivatives of Kabylake (Skylake client). + */ + return INTEL_BIGCORE_KABYLAKE; + case 0xA5: + case 0xA6: + return INTEL_BIGCORE_COMETLAKE; + case 0x66: + return INTEL_BIGCORE_CANNONLAKE; + case 0x55: + /* + Stepping = {6, 7} + -> Cascadelake + Stepping = {11} + -> Cooperlake + else + -> Skylake-avx512 + + These are all microarchitecturally indentical, so use + Skylake-avx512 for all of them. + */ + return INTEL_BIGCORE_SKYLAKE_AVX512; + case 0x6A: + case 0x6C: + case 0x7D: + case 0x7E: + case 0x9D: + return INTEL_BIGCORE_ICELAKE; + case 0x8C: + case 0x8D: + return INTEL_BIGCORE_TIGERLAKE; + case 0xA7: + return INTEL_BIGCORE_ROCKETLAKE; + case 0x8F: + return INTEL_BIGCORE_SAPPHIRERAPIDS; + case 0xB7: + case 0xBA: + case 0xBF: + return INTEL_BIGCORE_RAPTORLAKE; + case 0xCF: + return INTEL_BIGCORE_EMERALDRAPIDS; + case 0xAA: + case 0xAC: + return INTEL_BIGCORE_METEORLAKE; + case 0xbd: + return INTEL_BIGCORE_LUNARLAKE; + case 0xc6: + return INTEL_BIGCORE_ARROWLAKE; + case 0xAD: + case 0xAE: + return INTEL_BIGCORE_GRANITERAPIDS; + case 0x8A: + return INTEL_MIXED_LAKEFIELD; + case 0x97: + case 0x9A: + case 0xBE: + return INTEL_MIXED_ALDERLAKE; + case 0x85: + return INTEL_KNIGHTS_MILL; + case 0x57: + return INTEL_KNIGHTS_LANDING; + default: + return INTEL_UNKNOWN; + } +} + static inline void init_cpu_features (struct cpu_features *cpu_features) { @@ -453,129 +663,147 @@ init_cpu_features (struct cpu_features *cpu_features) if (family == 0x06) { model += extended_model; - switch (model) + unsigned int microarch + = intel_get_fam6_microarch (model, stepping); + + switch (microarch) { - case 0x1c: - case 0x26: - /* BSF is slow on Atom. */ + /* Atom / KNL tuning. */ + case INTEL_ATOM_BONNELL: + /* BSF is slow on Bonnell. */ cpu_features->preferred[index_arch_Slow_BSF] - |= bit_arch_Slow_BSF; + |= bit_arch_Slow_BSF; break; - case 0x57: - /* Knights Landing. Enable Silvermont optimizations. */ - - case 0x7a: - /* Unaligned load versions are faster than SSSE3 - on Goldmont Plus. */ - - case 0x5c: - case 0x5f: /* Unaligned load versions are faster than SSSE3 - on Goldmont. */ + on Airmont, Silvermont, Goldmont, and Goldmont Plus. */ + case INTEL_ATOM_AIRMONT: + case INTEL_ATOM_SILVERMONT: + case INTEL_ATOM_GOLDMONT: + case INTEL_ATOM_GOLDMONT_PLUS: - case 0x4c: - case 0x5a: - case 0x75: - /* Airmont is a die shrink of Silvermont. */ + /* Knights Landing. Enable Silvermont optimizations. */ + case INTEL_KNIGHTS_LANDING: - case 0x37: - case 0x4a: - case 0x4d: - case 0x5d: - /* Unaligned load versions are faster than SSSE3 - on Silvermont. */ cpu_features->preferred[index_arch_Fast_Unaligned_Load] - |= (bit_arch_Fast_Unaligned_Load - | bit_arch_Fast_Unaligned_Copy - | bit_arch_Prefer_PMINUB_for_stringop - | bit_arch_Slow_SSE4_2); + |= (bit_arch_Fast_Unaligned_Load + | bit_arch_Fast_Unaligned_Copy + | bit_arch_Prefer_PMINUB_for_stringop + | bit_arch_Slow_SSE4_2); break; - case 0x86: - case 0x96: - case 0x9c: + case INTEL_ATOM_TREMONT: /* Enable rep string instructions, unaligned load, unaligned - copy, pminub and avoid SSE 4.2 on Tremont. */ + copy, pminub and avoid SSE 4.2 on Tremont. */ cpu_features->preferred[index_arch_Fast_Rep_String] - |= (bit_arch_Fast_Rep_String - | bit_arch_Fast_Unaligned_Load - | bit_arch_Fast_Unaligned_Copy - | bit_arch_Prefer_PMINUB_for_stringop - | bit_arch_Slow_SSE4_2); + |= (bit_arch_Fast_Rep_String + | bit_arch_Fast_Unaligned_Load + | bit_arch_Fast_Unaligned_Copy + | bit_arch_Prefer_PMINUB_for_stringop + | bit_arch_Slow_SSE4_2); break; + /* + Default tuned Knights microarch. + case INTEL_KNIGHTS_MILL: + */ + + /* + Default tuned atom microarch. + case INTEL_ATOM_SIERRAFOREST: + case INTEL_ATOM_GRANDRIDGE: + */ + + /* Bigcore/Default Tuning. */ default: /* Unknown family 0x06 processors. Assuming this is one of Core i3/i5/i7 processors if AVX is available. */ if (!CPU_FEATURES_CPU_P (cpu_features, AVX)) break; /* Fall through. */ - - case 0x1a: - case 0x1e: - case 0x1f: - case 0x25: - case 0x2c: - case 0x2e: - case 0x2f: + case INTEL_BIGCORE_NEHALEM: + case INTEL_BIGCORE_WESTMERE: /* Rep string instructions, unaligned load, unaligned copy, and pminub are fast on Intel Core i3, i5 and i7. */ cpu_features->preferred[index_arch_Fast_Rep_String] - |= (bit_arch_Fast_Rep_String - | bit_arch_Fast_Unaligned_Load - | bit_arch_Fast_Unaligned_Copy - | bit_arch_Prefer_PMINUB_for_stringop); + |= (bit_arch_Fast_Rep_String + | bit_arch_Fast_Unaligned_Load + | bit_arch_Fast_Unaligned_Copy + | bit_arch_Prefer_PMINUB_for_stringop); break; + + /* + Default tuned Bigcore microarch. + case INTEL_BIGCORE_SANDYBRIDGE: + case INTEL_BIGCORE_IVYBRIDGE: + case INTEL_BIGCORE_HASWELL: + case INTEL_BIGCORE_BROADWELL: + case INTEL_BIGCORE_SKYLAKE: + case INTEL_BIGCORE_KABYLAKE: + case INTEL_BIGCORE_COMETLAKE: + case INTEL_BIGCORE_SKYLAKE_AVX512: + case INTEL_BIGCORE_CANNONLAKE: + case INTEL_BIGCORE_ICELAKE: + case INTEL_BIGCORE_TIGERLAKE: + case INTEL_BIGCORE_ROCKETLAKE: + case INTEL_BIGCORE_RAPTORLAKE: + case INTEL_BIGCORE_METEORLAKE: + case INTEL_BIGCORE_LUNARLAKE: + case INTEL_BIGCORE_ARROWLAKE: + case INTEL_BIGCORE_SAPPHIRERAPIDS: + case INTEL_BIGCORE_EMERALDRAPIDS: + case INTEL_BIGCORE_GRANITERAPIDS: + */ + + /* + Default tuned Mixed (bigcore + atom SOC). + case INTEL_MIXED_LAKEFIELD: + case INTEL_MIXED_ALDERLAKE: + */ } - /* Disable TSX on some processors to avoid TSX on kernels that - weren't updated with the latest microcode package (which - disables broken feature by default). */ - switch (model) + /* Disable TSX on some processors to avoid TSX on kernels that + weren't updated with the latest microcode package (which + disables broken feature by default). */ + switch (microarch) { - case 0x55: + case INTEL_BIGCORE_SKYLAKE_AVX512: + /* 0x55 (Skylake-avx512) && stepping <= 5 disable TSX. */ if (stepping <= 5) goto disable_tsx; break; - case 0x8e: - /* NB: Although the errata documents that for model == 0x8e, - only 0xb stepping or lower are impacted, the intention of - the errata was to disable TSX on all client processors on - all steppings. Include 0xc stepping which is an Intel - Core i7-8665U, a client mobile processor. */ - case 0x9e: + + case INTEL_BIGCORE_KABYLAKE: + /* NB: Although the errata documents that for model == 0x8e + (kabylake skylake client), only 0xb stepping or lower are + impacted, the intention of the errata was to disable TSX on + all client processors on all steppings. Include 0xc + stepping which is an Intel Core i7-8665U, a client mobile + processor. */ if (stepping > 0xc) break; /* Fall through. */ - case 0x4e: - case 0x5e: - { + case INTEL_BIGCORE_SKYLAKE: /* Disable Intel TSX and enable RTM_ALWAYS_ABORT for processors listed in: https://www.intel.com/content/www/us/en/support/articles/000059422/processors.html */ -disable_tsx: + disable_tsx: CPU_FEATURE_UNSET (cpu_features, HLE); CPU_FEATURE_UNSET (cpu_features, RTM); CPU_FEATURE_SET (cpu_features, RTM_ALWAYS_ABORT); - } - break; - case 0x3f: - /* Xeon E7 v3 with stepping >= 4 has working TSX. */ - if (stepping >= 4) break; - /* Fall through. */ - case 0x3c: - case 0x45: - case 0x46: - /* Disable Intel TSX on Haswell processors (except Xeon E7 v3 - with stepping >= 4) to avoid TSX on kernels that weren't - updated with the latest microcode package (which disables - broken feature by default). */ - CPU_FEATURE_UNSET (cpu_features, RTM); - break; + + case INTEL_BIGCORE_HASWELL: + /* Xeon E7 v3 (model == 0x3f) with stepping >= 4 has working + TSX. Haswell also include other model numbers that have + working TSX. */ + if (model == 0x3f && stepping >= 4) + break; + + CPU_FEATURE_UNSET (cpu_features, RTM); + break; } } -- 2.39.3