[U-Boot] [PATCH 7/9][v2] net: tsec: Use portable types and accessors for BDs

Scott Wood
2013-10-04T15:50:46Z

On Fri, 2013-10-04 at 11:27 +0300, Claudiu Manoil wrote:
> On 10/3/2013 9:37 PM, Scott Wood wrote:
> > On Thu, 2013-10-03 at 14:48 +0300, Claudiu Manoil wrote:
> >> +static inline u16 read_txbd_stat(uint idx)
> >> +{
> >> + return in_be16((u16 __iomem *)&txbd[idx].status);
> >> +}
> >> +
> >> +static inline void write_txbd_stat(uint idx, u16 status)
> >> +{
> >> + out_be16((u16 __iomem *)&txbd[idx].status, status);
> >> +}
> >> +
> >> +static inline u16 read_rxbd_stat(uint idx)
> >> +{
> >> + return in_be16((u16 __iomem *)&rxbd[idx].status);
> >> +}
> >> +
> >> +static inline void write_rxbd_stat(uint idx, u16 status)
> >> +{
> >> + out_be16((u16 __iomem *)&rxbd[idx].status, status);
> >> +}
> >
> > Do you need __force on these to make sparse happy?
> >
> No, we don't need __force in this case, in_be/out_be are less
> restrictive and take plain unsigned pointers (not __beNN pointers).
> On the other hand, they require the __iomem address space marker, to
> make sparse happy.

I thought you'd need __force to convert a non-iomem pointer to an
__iomem pointer.

> > I'd rather see these declared as __iomem than use casts (at which point,
> > you probably don't need per-field accessor functions).
> >
> Me too, but I wasn't sure how to do that. I thought __iomem works with
> pointer declarations only. But it turns out it works this way too:

Even if that were the case, you could put it on the pointers, which is
how it's usually used.

>
> -static struct txbd8 txbd[TX_BUF_CNT] __aligned(8);
> -static struct rxbd8 rxbd[PKTBUFSRX] __aligned(8);
> [...]
> +static struct txbd8 __iomem txbd[TX_BUF_CNT] __aligned(8);
> +static struct rxbd8 __iomem rxbd[PKTBUFSRX] __aligned(8);
>
> [...]
> - for (i = 0; read_txbd_stat(tx_idx) & TXBD_READY; i++) {
> + for (i = 0; in_be16(&txbd[tx_idx].status) & TXBD_READY; i++) {
> [...]
>
> And sparse doesn't complain about it. In this case I'll drop the
> read_txbd_stat() and friends. Is this acceptable?

Yes.

-Scott