target/linux/generic-2.6/patches-2.6.27/023-mips_delay_gcc4.4.0.patch

   1 From: Wu Zhangjin <wuzj@lemote.com>
   2
   3 the gcc 4.4 support for MIPS mostly refer to this PATCH:
   4 http://www.nabble.com/-PATCH--MIPS:-Handle-removal-of-%27h%27-constraint-in-GCC-4.4-td22192768.html
   5 but have been tuned a little.
   6
   7 because only gcc 4.4 have loongson-specific support, so, we need to
   8 choose the suitable -march argument for gcc <= 4.3 and gcc >= 4.4, and
   9 we also need to consider use -march=loongson2e and -march=loongson2f for
  10 loongson2e and loongson2f respectively. this is handled by adding two
  11 new kernel options: CPU_LOONGSON2E and CPU_LOONGSON2F(thanks for the
  12 solutin provided by ZhangLe).
  13
  14 I have tested it on FuLoong(2f) in 32bit and 64bit with gcc-4.4 and
  15 gcc-4.3. so, basically, it works.
  16
  17 Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
  18 ---
  19  arch/mips/Makefile               |    9 +++++-
  20  arch/mips/include/asm/compiler.h |   10 ++++++
  21  arch/mips/include/asm/delay.h    |   58 +++++++++++++++++++++++++------------
  22  3 files changed, 57 insertions(+), 20 deletions(-)
  23
  24 diff --git a/arch/mips/Makefile b/arch/mips/Makefile
  25 index a25c2e5..1ee5504 100644
  26 --- a/arch/mips/Makefile
  27 +++ b/arch/mips/Makefile
  28 @@ -120,7 +120,14 @@ cflags-$(CONFIG_CPU_R4300) += -march=r4300 -Wa,--trap
  29  cflags-$(CONFIG_CPU_VR41XX)    += -march=r4100 -Wa,--trap
  30  cflags-$(CONFIG_CPU_R4X00)     += -march=r4600 -Wa,--trap
  31  cflags-$(CONFIG_CPU_TX49XX)    += -march=r4600 -Wa,--trap
  32 -cflags-$(CONFIG_CPU_LOONGSON2) += -march=r4600 -Wa,--trap
  33 +
  34 +# only gcc >= 4.4 have the loongson-specific support
  35 +cflags-$(CONFIG_CPU_LOONGSON2) += -Wa,--trap
  36 +cflags-$(CONFIG_CPU_LOONGSON2E)        += $(shell if [ $(call cc-version) -lt 0440 ] ; then \
  37 +       echo $(call cc-option,-march=r4600); else echo $(call cc-option,-march=loongson2e); fi ;)
  38 +cflags-$(CONFIG_CPU_LOONGSON2F)        += $(shell if [ $(call cc-version) -lt 0440 ] ; then \
  39 +       echo $(call cc-option,-march=r4600); else echo $(call cc-option,-march=loongson2f); fi ;)
  40 +
  41  cflags-$(CONFIG_CPU_MIPS32_R1) += $(call cc-option,-march=mips32,-mips32 -U_MIPS_ISA -D_MIPS_ISA=_MIPS_ISA_MIPS32) \
  42                         -Wa,-mips32 -Wa,--trap
  43  cflags-$(CONFIG_CPU_MIPS32_R2) += $(call cc-option,-march=mips32r2,-mips32r2 -U_MIPS_ISA -D_MIPS_ISA=_MIPS_ISA_MIPS32) \
  44 diff --git a/include/asm-mips/compiler.h b/include/asm-mips/compiler.h
  45 index 71f5c5c..95256a8 100644
  46 --- a/include/asm-mips/compiler.h
  47 +++ b/include/asm-mips/compiler.h
  48 @@ -1,5 +1,6 @@
  49  /*
  50   * Copyright (C) 2004, 2007  Maciej W. Rozycki
  51 + * Copyright (C) 2009  Wu Zhangjin, wuzj@lemote.com
  52   *
  53   * This file is subject to the terms and conditions of the GNU General Public
  54   * License.  See the file "COPYING" in the main directory of this archive
  55 @@ -16,4 +17,13 @@
  56  #define GCC_REG_ACCUM "accum"
  57  #endif
  58
  59 +#if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 4)
  60 +#define GCC_NO_H_CONSTRAINT
  61 +#ifdef CONFIG_64BIT
  62 +typedef unsigned int uintx_t __attribute__((mode(TI)));
  63 +#else
  64 +typedef u64 uintx_t;
  65 +#endif
  66 +#endif
  67 +
  68  #endif /* _ASM_COMPILER_H */
  69 diff --git a/include/asm-mips/delay.h b/include/asm-mips/delay.h
  70 index b0bccd2..00d7969 100644
  71 --- a/include/asm-mips/delay.h
  72 +++ b/include/asm-mips/delay.h
  73 @@ -7,6 +7,7 @@
  74   * Copyright (C) 1995 - 2000, 01, 03 by Ralf Baechle
  75   * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
  76   * Copyright (C) 2007  Maciej W. Rozycki
  77 + * Copyright (C) 2009  Wu Zhangjin, wuzj@lemote.com
  78   */
  79  #ifndef _ASM_DELAY_H
  80  #define _ASM_DELAY_H
  81 @@ -48,6 +49,43 @@ static inline void __delay(unsigned long loops)
  82                 : "0" (loops), "r" (1));
  83  }
  84
  85 +/*
  86 + * convert usecs to loops
  87 + *
  88 + * handle removal of 'h' constraint in GCC 4.4
  89 + */
  90 +
  91 +#ifndef GCC_NO_H_CONSTRAINT    /* gcc <= 4.3 */
  92 +static inline unsigned long __usecs_to_loops(unsigned long usecs,
  93 +               unsigned long lpj)
  94 +{
  95 +       unsigned long hi, lo;
  96 +
  97 +       if (sizeof(long) == 4)
  98 +               __asm__("multu\t%2, %3"
  99 +               : "=h" (usecs), "=l" (lo)
 100 +               : "r" (usecs), "r" (lpj)
 101 +               : GCC_REG_ACCUM);
 102 +       else if (sizeof(long) == 8 && !R4000_WAR)
 103 +               __asm__("dmultu\t%2, %3"
 104 +               : "=h" (usecs), "=l" (lo)
 105 +               : "r" (usecs), "r" (lpj)
 106 +               : GCC_REG_ACCUM);
 107 +       else if (sizeof(long) == 8 && R4000_WAR)
 108 +               __asm__("dmultu\t%3, %4\n\tmfhi\t%0"
 109 +               : "=r" (usecs), "=h" (hi), "=l" (lo)
 110 +               : "r" (usecs), "r" (lpj)
 111 +               : GCC_REG_ACCUM);
 112 +
 113 +       return usecs;
 114 +}
 115 +#else  /* GCC_NO_H_CONSTRAINT, gcc >= 4.4 */
 116 +static inline unsigned long __usecs_to_loops(unsigned long usecs,
 117 +               unsigned long lpj)
 118 +{
 119 +       return ((uintx_t)usecs * lpj) >> BITS_PER_LONG;
 120 +}
 121 +#endif
 122
 123  /*
 124   * Division by multiplication: you don't have to worry about
 125 @@ -62,8 +100,6 @@ static inline void __delay(unsigned long loops)
 126
 127  static inline void __udelay(unsigned long usecs, unsigned long lpj)
 128  {
 129 -       unsigned long hi, lo;
 130 -
 131         /*
 132          * The rates of 128 is rounded wrongly by the catchall case
 133          * for 64-bit.  Excessive precission?  Probably ...
 134 @@ -77,23 +113,7 @@ static inline void __udelay(unsigned long usecs, unsigned long lpj)
 135                                    0x80000000ULL) >> 32);
 136  #endif
 137
 138 -       if (sizeof(long) == 4)
 139 -               __asm__("multu\t%2, %3"
 140 -               : "=h" (usecs), "=l" (lo)
 141 -               : "r" (usecs), "r" (lpj)
 142 -               : GCC_REG_ACCUM);
 143 -       else if (sizeof(long) == 8 && !R4000_WAR)
 144 -               __asm__("dmultu\t%2, %3"
 145 -               : "=h" (usecs), "=l" (lo)
 146 -               : "r" (usecs), "r" (lpj)
 147 -               : GCC_REG_ACCUM);
 148 -       else if (sizeof(long) == 8 && R4000_WAR)
 149 -               __asm__("dmultu\t%3, %4\n\tmfhi\t%0"
 150 -               : "=r" (usecs), "=h" (hi), "=l" (lo)
 151 -               : "r" (usecs), "r" (lpj)
 152 -               : GCC_REG_ACCUM);
 153 -
 154 -       __delay(usecs);
 155 +       __delay(__usecs_to_loops(usecs, lpj));
 156  }
 157
 158  #define __udelay_val cpu_data[raw_smp_processor_id()].udelay_val
 159 --
 160 1.6.0.4
 161
 162
 163