target-mips: Fix incorrect reads and writes to DSPControl register

From: Petar Jovanovic <petarj@mips.com>

Upper 4 bits of ccond (bits 31..28 ) of DSPControl register are not used in
the MIPS32 architecture. They are used in the MIPS64 architecture. For MIPS32
these bits must be written as zero, and return zero on read.

The change fixes writes (WRDSP) and reads (RDDSP) to the register. It also fixes
the tests that use these instructions, and makes them smaller and simpler.

Signed-off-by: Petar Jovanovic <petarj@mips.com>
---
 target-mips/dsp_helper.c          |    8 ++++++++
 tests/tcg/mips/mips32-dsp/rddsp.c |   32 ++++++++++++--------------------
 tests/tcg/mips/mips32-dsp/wrdsp.c |   32 ++++++++++++--------------------
 3 files changed, 32 insertions(+), 40 deletions(-)

On Thu, Dec 06, 2012 at 08:30:35PM +0100, Petar Jovanovic wrote:
> From: Petar Jovanovic <petarj@mips.com>
> 
> Upper 4 bits of ccond (bits 31..28 ) of DSPControl register are not used in
> the MIPS32 architecture. They are used in the MIPS64 architecture. For MIPS32
> these bits must be written as zero, and return zero on read.
> 
> The change fixes writes (WRDSP) and reads (RDDSP) to the register. It also fixes
> the tests that use these instructions, and makes them smaller and simpler.
> 
> Signed-off-by: Petar Jovanovic <petarj@mips.com>
> ---
>  target-mips/dsp_helper.c          |    8 ++++++++
>  tests/tcg/mips/mips32-dsp/rddsp.c |   32 ++++++++++++--------------------
>  tests/tcg/mips/mips32-dsp/wrdsp.c |   32 ++++++++++++--------------------
>  3 files changed, 32 insertions(+), 40 deletions(-)
> 
> diff --git a/target-mips/dsp_helper.c b/target-mips/dsp_helper.c
> index 14daf91..acf7ceb 100644
> --- a/target-mips/dsp_helper.c
> +++ b/target-mips/dsp_helper.c
> @@ -3948,7 +3948,11 @@ void helper_wrdsp(target_ulong rs, target_ulong mask_num, CPUMIPSState *env)
>      if (mask[4] == 1) {
>          overwrite &= 0x00FFFFFF;
>          newbits   &= 0x00FFFFFF;
> +#if defined(TARGET_MIPS64)
>          newbits   |= 0xFF000000 & rs;
> +#else
> +        newbits   |= 0x0F000000 & rs;
> +#endif
>      }
>  
>      if (mask[5] == 1) {
> @@ -3999,7 +4003,11 @@ target_ulong helper_rddsp(target_ulong masknum, CPUMIPSState *env)
>      }
>  
>      if (mask[4] == 1) {
> +#if defined(TARGET_MIPS64)
>          temp |= dsp & 0xFF000000;
> +#else
> +        temp |= dsp & 0x0F000000;
> +#endif
>      }
>  
>      if (mask[5] == 1) {
> diff --git a/tests/tcg/mips/mips32-dsp/rddsp.c b/tests/tcg/mips/mips32-dsp/rddsp.c
> index e8948ec..2f30285 100644
> --- a/tests/tcg/mips/mips32-dsp/rddsp.c
> +++ b/tests/tcg/mips/mips32-dsp/rddsp.c
> @@ -6,14 +6,13 @@ int main()
>      int dsp_i, dsp_o;
>      int ccond_i, outflag_i, efi_i, c_i, scount_i, pos_i;
>      int ccond_o, outflag_o, efi_o, c_o, scount_o, pos_o;
> -    int ccond_r, outflag_r, efi_r, c_r, scount_r, pos_r;
>  
> -    ccond_i   = 0x000000BC;/* 4 */
> -    outflag_i = 0x0000001B;/* 3 */
> -    efi_i     = 0x00000001;/* 5 */
> -    c_i       = 0x00000001;/* 2 */
> -    scount_i  = 0x0000000F;/* 1 */
> -    pos_i     = 0x0000000C;/* 0 */
> +    ccond_i   = 0x0000000C;  /* 4 */
> +    outflag_i = 0x0000001B;  /* 3 */
> +    efi_i     = 0x00000001;  /* 5 */
> +    c_i       = 0x00000001;  /* 2 */
> +    scount_i  = 0x0000000F;  /* 1 */
> +    pos_i     = 0x0000000C;  /* 0 */
>  
>      dsp_i = (ccond_i   << 24) | \
>              (outflag_i << 16) | \
> @@ -22,13 +21,6 @@ int main()
>              (scount_i  <<  7) | \
>              pos_i;
>  
> -    ccond_r   = ccond_i;
> -    outflag_r = outflag_i;
> -    efi_r     = efi_i;
> -    c_r       = c_i;
> -    scount_r  = scount_i;
> -    pos_r     = pos_i;
> -
>      __asm
>          ("wrdsp %1, 0x3F\n\t"
>           "rddsp %0, 0x3F\n\t"
> @@ -43,12 +35,12 @@ int main()
>      scount_o  = (dsp_o >>  7) & 0x3F;
>      pos_o     =  dsp_o & 0x1F;
>  
> -    assert(ccond_o   == ccond_r);
> -    assert(outflag_o == outflag_r);
> -    assert(efi_o     == efi_r);
> -    assert(c_o       == c_r);
> -    assert(scount_o  == scount_r);
> -    assert(pos_o     == pos_r);
> +    assert(ccond_o   == ccond_i);
> +    assert(outflag_o == outflag_i);
> +    assert(efi_o     == efi_i);
> +    assert(c_o       == c_i);
> +    assert(scount_o  == scount_i);
> +    assert(pos_o     == pos_i);
>  
>      return 0;
>  }
> diff --git a/tests/tcg/mips/mips32-dsp/wrdsp.c b/tests/tcg/mips/mips32-dsp/wrdsp.c
> index e8948ec..dc54943 100644
> --- a/tests/tcg/mips/mips32-dsp/wrdsp.c
> +++ b/tests/tcg/mips/mips32-dsp/wrdsp.c
> @@ -6,14 +6,13 @@ int main()
>      int dsp_i, dsp_o;
>      int ccond_i, outflag_i, efi_i, c_i, scount_i, pos_i;
>      int ccond_o, outflag_o, efi_o, c_o, scount_o, pos_o;
> -    int ccond_r, outflag_r, efi_r, c_r, scount_r, pos_r;
>  
> -    ccond_i   = 0x000000BC;/* 4 */
> -    outflag_i = 0x0000001B;/* 3 */
> -    efi_i     = 0x00000001;/* 5 */
> -    c_i       = 0x00000001;/* 2 */
> -    scount_i  = 0x0000000F;/* 1 */
> -    pos_i     = 0x0000000C;/* 0 */
> +    ccond_i   = 0x000000BC;  /* 4 */
> +    outflag_i = 0x0000001B;  /* 3 */
> +    efi_i     = 0x00000001;  /* 5 */
> +    c_i       = 0x00000001;  /* 2 */
> +    scount_i  = 0x0000000F;  /* 1 */
> +    pos_i     = 0x0000000C;  /* 0 */
>  
>      dsp_i = (ccond_i   << 24) | \
>              (outflag_i << 16) | \
> @@ -22,13 +21,6 @@ int main()
>              (scount_i  <<  7) | \
>              pos_i;
>  
> -    ccond_r   = ccond_i;
> -    outflag_r = outflag_i;
> -    efi_r     = efi_i;
> -    c_r       = c_i;
> -    scount_r  = scount_i;
> -    pos_r     = pos_i;
> -
>      __asm
>          ("wrdsp %1, 0x3F\n\t"
>           "rddsp %0, 0x3F\n\t"
> @@ -43,12 +35,12 @@ int main()
>      scount_o  = (dsp_o >>  7) & 0x3F;
>      pos_o     =  dsp_o & 0x1F;
>  
> -    assert(ccond_o   == ccond_r);
> -    assert(outflag_o == outflag_r);
> -    assert(efi_o     == efi_r);
> -    assert(c_o       == c_r);
> -    assert(scount_o  == scount_r);
> -    assert(pos_o     == pos_r);
> +    assert(ccond_o   == (ccond_i & 0x0F));
> +    assert(outflag_o == outflag_i);
> +    assert(efi_o     == efi_i);
> +    assert(c_o       == c_i);
> +    assert(scount_o  == scount_i);
> +    assert(pos_o     == pos_i);
>  
>      return 0;
>  }

Thanks, applied.