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  )
    21  
    22  func initOptions() {
    23  	options = []option{
    24  		{Name: "lsx", Feature: &Loong64.HasLSX},
    25  		{Name: "lasx", Feature: &Loong64.HasLASX},
    26  		{Name: "crc32", Feature: &Loong64.HasCRC32},
    27  		{Name: "lam_bh", Feature: &Loong64.HasLAM_BH},
    28  		{Name: "lamcas", Feature: &Loong64.HasLAMCAS},
    29  	}
    30  
    31  	// The CPUCFG data on Loong64 only reflects the hardware capabilities,
    32  	// not the kernel support status, so features such as LSX and LASX that
    33  	// require kernel support cannot be obtained from the CPUCFG data.
    34  	//
    35  	// These features only require hardware capability support and do not
    36  	// require kernel specific support, so they can be obtained directly
    37  	// through CPUCFG
    38  	cfg1 := get_cpucfg(1)
    39  	cfg2 := get_cpucfg(2)
    40  
    41  	Loong64.HasCRC32 = cfgIsSet(cfg1, cpucfg1_CRC32)
    42  	Loong64.HasLAMCAS = cfgIsSet(cfg2, cpucfg2_LAMCAS)
    43  	Loong64.HasLAM_BH = cfgIsSet(cfg2, cpucfg2_LAM_BH)
    44  }
    45  
    46  func get_cpucfg(reg uint32) uint32
    47  
    48  func cfgIsSet(cfg uint32, val uint32) bool {
    49  	return cfg&val != 0
    50  }
    51
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