[SLOF] [PATCH slof] pci-phb: Reimplement dma-map-in/out

[Segher Boessenkool]

Hi!

On Thu, Nov 14, 2019 at 02:33:41PM +1100, Alexey Kardashevskiy wrote:
> +: align-4k
> +    fff not and
> +;

This is aligning down.  "align" means "align upwards" normally.  The word
"align" aligns the data space, while "aligned" aligns a pointer.  SLOF also
has a utility word "#aligned" to align to some certain boundary.  So you
would do

: align-4k  ( a - a ) 1000 #aligned ;

but that sligns *upwards*.

: trunc-4k  ( a - a ) -1000 and ;

if you want a lower address, instead (less often useful, btw).

(OF always is two's complement, you can write -1000 instead of fff invert).

> +\ grub does not align allocated addresses to the size
> +\ so when mapping in dma-map-in, sometime we call H_PUT_TCE more than
> +\ bm-alloc allocated
> +: dma-align ( virt size -- virt aligned-size )
> +    over fff and + fff + fff not and
> +;

: dma-align  ( virt size -- virt a-size )  over fff and +  1000 @aligned ;

fff + fff not and   is just  1000 #aligned  .

I don't understand why you are adding the low twelve bits of the address
to the size as well?


Segher