cpu_loong64.go

     1  // Copyright 2022 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  //go:build loong64
     6  
     7  package cpu
     8  
     9  const cacheLineSize = 64
    10  
    11  // Bit fields for CPUCFG registers, Related reference documents:
    12  // https://loongson.github.io/LoongArch-Documentation/LoongArch-Vol1-EN.html#_cpucfg
    13  const (
    14  	// CPUCFG1 bits
    15  	cpucfg1_CRC32 = 1 << 25
    16  
    17  	// CPUCFG2 bits
    18  	cpucfg2_LAM_BH      = 1 << 27
    19  	cpucfg2_LAMCAS      = 1 << 28
    20  	cpucfg2_LLACQ_SCREL = 1 << 29
    21  	cpucfg2_SCQ         = 1 << 30
    22  
    23  	// CPUCFG3 bits
    24  	cpucfg3_DBAR_HINTS = 1 << 17
    25  )
    26  
    27  func initOptions() {
    28  	options = []option{
    29  		{Name: "lsx", Feature: &Loong64.HasLSX},
    30  		{Name: "lasx", Feature: &Loong64.HasLASX},
    31  		{Name: "crc32", Feature: &Loong64.HasCRC32},
    32  		{Name: "lam_bh", Feature: &Loong64.HasLAM_BH},
    33  		{Name: "lamcas", Feature: &Loong64.HasLAMCAS},
    34  		{Name: "llacq_screl", Feature: &Loong64.HasLLACQ_SCREL},
    35  		{Name: "scq", Feature: &Loong64.HasSCQ},
    36  		{Name: "dbar_hints", Feature: &Loong64.HasDBAR_HINTS},
    37  	}
    38  
    39  	// The CPUCFG data on Loong64 only reflects the hardware capabilities,
    40  	// not the kernel support status, so features such as LSX and LASX that
    41  	// require kernel support cannot be obtained from the CPUCFG data.
    42  	//
    43  	// These features only require hardware capability support and do not
    44  	// require kernel specific support, so they can be obtained directly
    45  	// through CPUCFG
    46  	cfg1 := get_cpucfg(1)
    47  	cfg2 := get_cpucfg(2)
    48  	cfg3 := get_cpucfg(3)
    49  
    50  	Loong64.HasCRC32 = cfgIsSet(cfg1, cpucfg1_CRC32)
    51  	Loong64.HasLAMCAS = cfgIsSet(cfg2, cpucfg2_LAMCAS)
    52  	Loong64.HasLAM_BH = cfgIsSet(cfg2, cpucfg2_LAM_BH)
    53  	Loong64.HasLLACQ_SCREL = cfgIsSet(cfg2, cpucfg2_LLACQ_SCREL)
    54  	Loong64.HasSCQ = cfgIsSet(cfg2, cpucfg2_SCQ)
    55  	Loong64.HasDBAR_HINTS = cfgIsSet(cfg3, cpucfg3_DBAR_HINTS)
    56  }
    57  
    58  func get_cpucfg(reg uint32) uint32
    59  
    60  func cfgIsSet(cfg uint32, val uint32) bool {
    61  	return cfg&val != 0
    62  }
    63
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