On Mon, 2017-11-06 at 20:41 +1100, Michael Ellerman wrote:
> Cyril Bur <cyril...@gmail.com> writes:
>
> > diff --git a/arch/powerpc/platforms/powernv/opal-async.c
> > b/arch/powerpc/platforms/powernv/opal-async.c
> > index c43421ab2d2f..fbae8a37ce2c 100644
> > --- a/arch/powerpc/platforms/powernv/opal-async.c
> > +++ b/arch/powerpc/platforms/powernv/opal-async.c
> > @@ -23,40 +23,45 @@
> > #include <asm/machdep.h>
> > #include <asm/opal.h>
> >
> > -#define N_ASYNC_COMPLETIONS 64
> > +enum opal_async_token_state {
> > + ASYNC_TOKEN_UNALLOCATED = 0,
> > + ASYNC_TOKEN_ALLOCATED,
> > + ASYNC_TOKEN_COMPLETED
> > +};
> > +
> > +struct opal_async_token {
> > + enum opal_async_token_state state;
> > + struct opal_msg response;
> > +};
> >
> > -static DECLARE_BITMAP(opal_async_complete_map, N_ASYNC_COMPLETIONS) =
> > {~0UL};
> > -static DECLARE_BITMAP(opal_async_token_map, N_ASYNC_COMPLETIONS);
> > static DECLARE_WAIT_QUEUE_HEAD(opal_async_wait);
> > static DEFINE_SPINLOCK(opal_async_comp_lock);
> > static struct semaphore opal_async_sem;
> > -static struct opal_msg *opal_async_responses;
> > static unsigned int opal_max_async_tokens;
> > +static struct opal_async_token *opal_async_tokens;
> >
> > static int __opal_async_get_token(void)
> > {
> > unsigned long flags;
> > - int token;
> > + int token = -EBUSY;
> >
> > spin_lock_irqsave(&opal_async_comp_lock, flags);
> > - token = find_first_bit(opal_async_complete_map, opal_max_async_tokens);
> > - if (token >= opal_max_async_tokens) {
> > - token = -EBUSY;
> > - goto out;
> > + for (token = 0; token < opal_max_async_tokens; token++) {
> > + if (opal_async_tokens[token].state == ASYNC_TOKEN_UNALLOCATED) {
> > + opal_async_tokens[token].state = ASYNC_TOKEN_ALLOCATED;
> > + goto out;
> > + }
> > }
> > -
> > - if (__test_and_set_bit(token, opal_async_token_map)) {
> > - token = -EBUSY;
> > - goto out;
> > - }
> > -
> > - __clear_bit(token, opal_async_complete_map);
> > -
> > out:
> > spin_unlock_irqrestore(&opal_async_comp_lock, flags);
> > return token;
> > }
>
> Resulting in:
>
> static int __opal_async_get_token(void)
> {
> unsigned long flags;
> + int token = -EBUSY;
>
> spin_lock_irqsave(&opal_async_comp_lock, flags);
> + for (token = 0; token < opal_max_async_tokens; token++) {
> + if (opal_async_tokens[token].state == ASYNC_TOKEN_UNALLOCATED) {
> + opal_async_tokens[token].state = ASYNC_TOKEN_ALLOCATED;
> + goto out;
> + }
> }
> out:
> spin_unlock_irqrestore(&opal_async_comp_lock, flags);
> return token;
> }
>
> So when no unallocated token is found we return opal_max_async_tokens :(
>
> I changed it to:
>
> static int __opal_async_get_token(void)
> {
> unsigned long flags;
> int i, token = -EBUSY;
>
> spin_lock_irqsave(&opal_async_comp_lock, flags);
>
> for (i = 0; i < opal_max_async_tokens; i++) {
> if (opal_async_tokens[i].state == ASYNC_TOKEN_UNALLOCATED) {
> opal_async_tokens[i].state = ASYNC_TOKEN_ALLOCATED;
> token = i;
> break;
> }
> }
>
> spin_unlock_irqrestore(&opal_async_comp_lock, flags);
> return token;
> }
>
>
Thanks!!
> >
> > +/*
> > + * Note: If the returned token is used in an opal call and opal returns
> > + * OPAL_ASYNC_COMPLETION you MUST opal_async_wait_response() before
>
> ^
> call
>
>
> cheers
