On Wed, 26 Jun 2013, Geert Uytterhoeven wrote:
> arch/m68k/mac/iop.c has:
>
> static struct iop_msg iop_msg_pool[NUM_IOP_MSGS];
>
> As iop_msg_pool consumes 4928 bytes, it should be allocated dynamically,
> especially for multi-platform kernels not running on Mac.
I agree. Though I don't care much for multi-platform kernels: bloat in
portable code is easily excused when most users of that code run it on
recent hardware. We don't have that excuse.
>
> Furthermore:
>
> /*
> * Initialize the IOPs, if present.
> */
>
> void __init iop_init(void)
> {
> int i;
>
> if (iop_scc_present) {
> printk("IOP: detected SCC IOP at %p\n",
> iop_base[IOP_NUM_SCC]);
> }
> if (iop_ism_present) {
> printk("IOP: detected ISM IOP at %p\n",
> iop_base[IOP_NUM_ISM]);
> iop_start(iop_base[IOP_NUM_ISM]);
> iop_alive(iop_base[IOP_NUM_ISM]); /* clears the alive flag */
> }
Maybe use kcalloc() to allocate iop_msg_pool, iop_send_queue and
iop_listeners and remove all of the following initialisation. I don't see
a convenient way to call kfree() though.
>
> /* Make the whole pool available and empty the queues */
>
> for (i = 0 ; i < NUM_IOP_MSGS ; i++) {
> iop_msg_pool[i].status = IOP_MSGSTATUS_UNUSED;
> }
>
> for (i = 0 ; i < NUM_IOP_CHAN ; i++) {
> iop_send_queue[IOP_NUM_SCC][i] = NULL;
> iop_send_queue[IOP_NUM_ISM][i] = NULL;
> iop_listeners[IOP_NUM_SCC][i].devname = NULL;
> iop_listeners[IOP_NUM_SCC][i].handler = NULL;
> iop_listeners[IOP_NUM_ISM][i].devname = NULL;
> iop_listeners[IOP_NUM_ISM][i].handler = NULL;
> }
> }
>
> However, despite the comment at the top, all of the above is done
> unconditionally?
Seems so. And it is pointless AFAICS with grep.
> Do all Macs use the IOP functionality?
No. iop_scc_present and iop_ism_present are accurate.
So far, the only driver to make use of this functionality is
drivers/macintosh/adb-iop.c:
int adb_iop_probe(void)
{
if (!iop_ism_present) return -ENODEV;
return 0;
}
Finn
>
> P.S. Before anyone mentions zorro_autocon: yes, it's on my list ;-)
>
> Gr{oetje,eeting}s,
>
> Geert
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