On Friday, May 20, 2016 6:49 AM, Ian Abbott wrote:
> Rename the macros for the PLX PCI 9080 LAS0RR and LAS1RR registers in
> "plx9080.h", using the prefix `PLX_LASRR_`.  Make use of the `BIT(x)`
> and `GENMASK(h,l)` macros to define the values.
>
> Define a macro `PLX_LASRR_PREFETCH` for the "prefetchable memory" bit in
> this register, and define a macro `PLX_LASRR_MLOC_MASK` to mask the PCI
> memory location control bits.
>
> Signed-off-by: Ian Abbott <abbo...@mev.co.uk>
> ---

[snip]

> diff --git a/drivers/staging/comedi/drivers/plx9080.h 
> b/drivers/staging/comedi/drivers/plx9080.h
> index 92d2480..8788117 100644
> --- a/drivers/staging/comedi/drivers/plx9080.h
> +++ b/drivers/staging/comedi/drivers/plx9080.h
> @@ -54,14 +54,16 @@ struct plx_dma_desc {
>  /* Local Address Space 1 Range Register */
>  #define PLX_REG_LAS1RR               0x00f0
>  
> -#define  LRNG_IO           0x00000001        /* Map to: 1=I/O, 0=Mem */
> -#define  LRNG_ANY32        0x00000000        /* Locate anywhere in 32 bit */
> -#define  LRNG_LT1MB        0x00000002        /* Locate in 1st meg */
> -#define  LRNG_ANY64        0x00000004        /* Locate anywhere in 64 bit */
> -/*  bits that specify range for memory io */
> -#define  LRNG_MEM_MASK     0xfffffff0
> -/*  bits that specify range for normal io */
> -#define  LRNG_IO_MASK     0xfffffffc
> +#define PLX_LASRR_IO         BIT(0)          /* Map to: 1=I/O, 0=Mem */
> +#define PLX_LASRR_ANY32              (BIT(1) * 0)    /* Locate anywhere in 
> 32 bit */
> +#define PLX_LASRR_LT1MB              (BIT(1) * 1)    /* Locate in 1st meg */
> +#define PLX_LASRR_ANY64              (BIT(1) * 2)    /* Locate anywhere in 
> 64 bit */

The (BIT(n) * x) looks ugly.

These bit define the memory space encoding. I would prefer something
like this:

#define PLX_LASSR_MLOC(x)               (((x) & 0x3) << 1)
#define PLX_LASSR_MLOC_ANY32    PLX_LASSR_MLOC(0)
#define PLX_LASSR_MLOC_LT1MB    PLX_LASSR_MLOC(1)
#define PLX_LASSR_MLOC_ANY64    PLX_LASSR_MLOC(2)

> +#define PLX_LASRR_MLOC_MASK  GENMASK(2, 1)   /* Memory location bits */

I guess the GENMASK() macro is common but it's currently
not used by any of the comedi code.

Using the macro above, the 'mask' would be:

#define PLX_LASSR_MLOC_MASK     PLX_LASSR_MLOC(3)

> +#define PLX_LASRR_PREFETCH   BIT(3)          /* Memory is prefetchable */
> +/* bits that specify range for memory space decode bits */
> +#define PLX_LASRR_MEM_MASK   GENMASK(31, 4)
> +/* bits that specify range for i/o space decode bits */
> +#define PLX_LASRR_IO_MASK    GENMASK(31, 2)
 
I suppose the GENMASK() use makes sense for these.

Regards,
Hartley

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