Thanks Peter.

On Tue, Dec 01, 2015 at 02:49:11PM -0800, H. Peter Anvin wrote:
> On 12/01/15 14:18, Sinclair Yeh wrote:
> > These macros will be used by multiple VMWare modules for handling
> > host communication.
> 
> > +   __asm__ __volatile__ ("inl %%dx" :                              \
> 
> This is odd at best; the standard assembly form of this instruction is:
> 
>       inl (%dx),%eax

Ok, I'm not sure why this worked and compiled before.  Fixed.

> 
> Also, we don't need the underscored forms of asm and volatile for kernel
> code.
> 
> > +   __asm__ __volatile__ ("movq %13, %%rbp;"        \
> > +           "cld; rep outsb; "                      \
> > +           "movq %%rbp, %6" :                      \
> 
> cld shouldn't be necessary here, DF=0 is part of the normal ABI environment.
> 
> You also don't save/restore %rbp here, but you do below?  Seems very odd.

Good catch.  Fixed.

> 
> It might be better do so something like:
> 
> +#define VMW_PORT_HB_OUT(in1, in2, port_num, magic,     \
> +                     eax, ebx, ecx, edx, si, di, bp) \
> +({                                                     \
> +     __asm__ __volatile__ ("xchgq %6, %%rbp;"        \
> +             "cld; rep outsb; "                      \
> +             "xchgq %%rbp, %6" :                     \
> +             "=a"(eax),                              \
> +             "=b"(ebx),                              \
> +             "=c"(ecx),                              \
> +             "=d"(edx),                              \
> +             "+S"(si),                               \
> +             "+D"(di),                               \
> +             "+r"(bp) :                              \
> +             "a"(magic),                             \
> +             "b"(in1),                               \
> +             "c"(in2),                               \
> +             "d"(port_num) :                         \
> +             "memory", "cc");                        \
> +})

This is great.  Changed.

Updated patch set incoming.

Sinclair

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