[PATCH/v2] powerpc/5200: make BestComm gen_bd microcode exchangeable

[Grant Likely]

On Mon, Oct 5, 2009 at 11:41 AM, Albrecht Dreß <albrecht.dress at arcor.de> wrote:
> This patch adds a method for defining different microcodes than the pe-defined ones for the MPC52xx's BestComm General Buffer Descriptor (gen_db) tasks.  The default microcode is still the one from bcom_gen_bd_[rt]x_task, but it can be replaced by calling bcom_gen_bd_set_microcode() which is more efficient than explicitly loading it via bcom_load_image() after each bcom_gen_bd_[rt]x_reset().
>
> Except for a fixed tab vs. space formatting and the transfer format, there are no diffierences to the initial attempt.

Hmmm.  I've not been comfortable with this change, but it took me a
while to put my finger on exactly why.  In principle, I think it is a
good idea.  However, I don't want to merge it without any in-tree
users.

The other concern is that I don't like that the patch is only
applicable to gen_bd tasks.  I've been thinking about this for a
while, and I'm not exactly thrilled with the bestcomm layout which
keeps the bestcomm firmware separate from the only driver that
actually uses it (ie FEC firmware & support code is separate from the
FEC driver.  Same for ATA).  I don't like the fact that code which is
only ever used by the ATA driver is maintained completely separate
from it.  But I may be splitting hairs here and maybe I shouldn't be
too concerned about it.  Regardless, I'd think I'd rather see
something that isn't totally gen_bd specific.  Perhaps *microcode
should be part of the bcom_task structure?

Thoughts?

g.

>
> Signed-off-by: Albrecht Dreß <albrecht.dress at arcor.de>
>
>
> ---
>
>
> diff -uprN -X linux-2.6.32-rc3/Documentation/dontdiff linux-2.6.32-rc3-orig/arch/powerpc/sysdev/bestcomm/gen_bd.c linux-2.6.32-rc3/arch/powerpc/sysdev/bestcomm/gen_bd.c
> --- linux-2.6.32-rc3-orig/arch/powerpc/sysdev/bestcomm/gen_bd.c 2009-10-05 02:12:30.000000000 +0200
> +++ linux-2.6.32-rc3/arch/powerpc/sysdev/bestcomm/gen_bd.c      2009-10-05 14:52:31.000000000 +0200
> @@ -78,6 +78,7 @@ struct bcom_gen_bd_priv {
>        int             initiator;
>        int             ipr;
>        int             maxbufsize;
> +       u32             *microcode;
>  };
>
>
> @@ -104,6 +105,7 @@ bcom_gen_bd_rx_init(int queue_len, phys_
>        priv->initiator = initiator;
>        priv->ipr       = ipr;
>        priv->maxbufsize = maxbufsize;
> +       priv->microcode = bcom_gen_bd_rx_task;
>
>        if (bcom_gen_bd_rx_reset(tsk)) {
>                bcom_task_free(tsk);
> @@ -128,7 +130,7 @@ bcom_gen_bd_rx_reset(struct bcom_task *t
>        var = (struct bcom_gen_bd_rx_var *) bcom_task_var(tsk->tasknum);
>        inc = (struct bcom_gen_bd_rx_inc *) bcom_task_inc(tsk->tasknum);
>
> -       if (bcom_load_image(tsk->tasknum, bcom_gen_bd_rx_task))
> +       if (bcom_load_image(tsk->tasknum, priv->microcode))
>                return -1;
>
>        var->enable     = bcom_eng->regs_base +
> @@ -188,6 +190,7 @@ bcom_gen_bd_tx_init(int queue_len, phys_
>        priv->fifo      = fifo;
>        priv->initiator = initiator;
>        priv->ipr       = ipr;
> +       priv->microcode = bcom_gen_bd_tx_task;
>
>        if (bcom_gen_bd_tx_reset(tsk)) {
>                bcom_task_free(tsk);
> @@ -212,7 +215,7 @@ bcom_gen_bd_tx_reset(struct bcom_task *t
>        var = (struct bcom_gen_bd_tx_var *) bcom_task_var(tsk->tasknum);
>        inc = (struct bcom_gen_bd_tx_inc *) bcom_task_inc(tsk->tasknum);
>
> -       if (bcom_load_image(tsk->tasknum, bcom_gen_bd_tx_task))
> +       if (bcom_load_image(tsk->tasknum, priv->microcode))
>                return -1;
>
>        var->enable     = bcom_eng->regs_base +
> @@ -253,6 +256,15 @@ bcom_gen_bd_tx_release(struct bcom_task
>  }
>  EXPORT_SYMBOL_GPL(bcom_gen_bd_tx_release);
>
> +void
> +bcom_gen_bd_set_microcode(struct bcom_task *tsk, u32 *microcode)
> +{
> +       struct bcom_gen_bd_priv *priv = tsk->priv;
> +
> +       priv->microcode = microcode;
> +}
> +EXPORT_SYMBOL_GPL(bcom_gen_bd_set_microcode);
> +
>  /* ---------------------------------------------------------------------
>  * PSC support code
>  */
> diff -uprN -X linux-2.6.32-rc3/Documentation/dontdiff linux-2.6.32-rc3-orig/arch/powerpc/sysdev/bestcomm/gen_bd.h linux-2.6.32-rc3/arch/powerpc/sysdev/bestcomm/gen_bd.h
> --- linux-2.6.32-rc3-orig/arch/powerpc/sysdev/bestcomm/gen_bd.h 2009-10-05 02:12:30.000000000 +0200
> +++ linux-2.6.32-rc3/arch/powerpc/sysdev/bestcomm/gen_bd.h      2009-10-05 14:52:31.000000000 +0200
> @@ -43,6 +43,9 @@ bcom_gen_bd_tx_reset(struct bcom_task *t
>  extern void
>  bcom_gen_bd_tx_release(struct bcom_task *tsk);
>
> +extern void
> +bcom_gen_bd_set_microcode(struct bcom_task *tsk, u32 *microcode);
> +
>
>  /* PSC support utility wrappers */
>  struct bcom_task * bcom_psc_gen_bd_rx_init(unsigned psc_num, int queue_len,
>



-- 
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.