Re: [PATCH 4/8] mailbox: tegra-hsp: Refactor in preparation of mailboxes

[Mikko Perttunen <cyndis@xxxxxxxx>]

On 22.05.2018 18:36, Jon Hunter wrote:
> On 08/05/18 12:43, Mikko Perttunen wrote:
> > The HSP driver is currently in many places written with the assumption
> > of only supporting doorbells. Prepare for the addition of shared
> > mailbox support by removing these assumptions and cleaning up the code.
> >
> > Signed-off-by: Mikko Perttunen <mperttunen@xxxxxxxxxx>
> > ---
> >   drivers/mailbox/tegra-hsp.c | 124 
> > +++++++++++++++++++++++++++++---------------
> >   1 file changed, 82 insertions(+), 42 deletions(-)
> >
> > diff --git a/drivers/mailbox/tegra-hsp.c b/drivers/mailbox/tegra-hsp.c
> > index 0cde356c11ab..16eb970f2c9f 100644
> > --- a/drivers/mailbox/tegra-hsp.c
> > +++ b/drivers/mailbox/tegra-hsp.c
> > @@ -1,5 +1,5 @@
> >   /*
> > - * Copyright (c) 2016, NVIDIA CORPORATION.  All rights reserved.
> > + * Copyright (c) 2016-2018, NVIDIA CORPORATION.  All rights reserved.
> >    *
> >    * This program is free software; you can redistribute it and/or 
> > modify it
> >    * under the terms and conditions of the GNU General Public License,
> > @@ -42,6 +42,7 @@ struct tegra_hsp_channel;
> >   struct tegra_hsp;
> >   struct tegra_hsp_channel {
> > +    unsigned int type;
> >       struct tegra_hsp *hsp;
> >       struct mbox_chan *chan;
> >       void __iomem *regs;
> > @@ -55,6 +56,12 @@ struct tegra_hsp_doorbell {
> >       unsigned int index;
> >   };
> > +static inline struct tegra_hsp_doorbell *
> > +channel_to_doorbell(struct tegra_hsp_channel *channel)
> > +{
> > +    return container_of(channel, struct tegra_hsp_doorbell, channel);
> > +}
> > +
> >   struct tegra_hsp_db_map {
> >       const char *name;
> >       unsigned int master;
> > @@ -69,7 +76,7 @@ struct tegra_hsp {
> >       const struct tegra_hsp_soc *soc;
> >       struct mbox_controller mbox;
> >       void __iomem *regs;
> > -    unsigned int irq;
> > +    unsigned int doorbell_irq;
> >       unsigned int num_sm;
> >       unsigned int num_as;
> >       unsigned int num_ss;
> > @@ -194,7 +201,7 @@ tegra_hsp_doorbell_create(struct tegra_hsp *hsp, 
> > const char *name,
> >       if (!db)
> >           return ERR_PTR(-ENOMEM);
> > -    offset = (1 + (hsp->num_sm / 2) + hsp->num_ss + hsp->num_as) << 16;
> > +    offset = (1 + (hsp->num_sm / 2) + hsp->num_ss + hsp->num_as) * 
> > SZ_64K;
> >       offset += index * 0x100;
> >       db->channel.regs = hsp->regs + offset;
> > @@ -218,18 +225,8 @@ static void __tegra_hsp_doorbell_destroy(struct 
> > tegra_hsp_doorbell *db)
> >       kfree(db);
> >   }
> > -static int tegra_hsp_doorbell_send_data(struct mbox_chan *chan, void 
> > *data)
> > -{
> > -    struct tegra_hsp_doorbell *db = chan->con_priv;
> > -
> > -    tegra_hsp_channel_writel(&db->channel, 1, HSP_DB_TRIGGER);
> > -
> > -    return 0;
> > -}
> > -
> > -static int tegra_hsp_doorbell_startup(struct mbox_chan *chan)
> > +static int tegra_hsp_doorbell_startup(struct tegra_hsp_doorbell *db)
> >   {
> > -    struct tegra_hsp_doorbell *db = chan->con_priv;
> >       struct tegra_hsp *hsp = db->channel.hsp;
> >       struct tegra_hsp_doorbell *ccplex;
> >       unsigned long flags;
> > @@ -260,9 +257,8 @@ static int tegra_hsp_doorbell_startup(struct 
> > mbox_chan *chan)
> >       return 0;
> >   }
> > -static void tegra_hsp_doorbell_shutdown(struct mbox_chan *chan)
> > +static void tegra_hsp_doorbell_shutdown(struct tegra_hsp_doorbell *db)
> >   {
> > -    struct tegra_hsp_doorbell *db = chan->con_priv;
> >       struct tegra_hsp *hsp = db->channel.hsp;
> >       struct tegra_hsp_doorbell *ccplex;
> >       unsigned long flags;
> > @@ -281,35 +277,61 @@ static void tegra_hsp_doorbell_shutdown(struct 
> > mbox_chan *chan)
> >       spin_unlock_irqrestore(&hsp->lock, flags);
> >   }
> > -static const struct mbox_chan_ops tegra_hsp_doorbell_ops = {
> > -    .send_data = tegra_hsp_doorbell_send_data,
> > -    .startup = tegra_hsp_doorbell_startup,
> > -    .shutdown = tegra_hsp_doorbell_shutdown,
> > +static int tegra_hsp_send_data(struct mbox_chan *chan, void *data)
> > +{
> > +    struct tegra_hsp_channel *channel = chan->con_priv;
> > +    struct tegra_hsp_doorbell *db;
> > +
> > +    switch (channel->type) {
> > +    case TEGRA_HSP_MBOX_TYPE_DB:
> > +        db = channel_to_doorbell(channel);
> > +        tegra_hsp_channel_writel(&db->channel, 1, HSP_DB_TRIGGER);
>
> The above appears to be redundant. We go from channel to db and then end 
> up passing channels. Do we really need the 'db' struct above?

Fixed.

> > +    }
> > +
> > +    return -EINVAL;
>
> Does this function always return -EINVAL?

Fixed.

> > +}
> > +
> > +static int tegra_hsp_startup(struct mbox_chan *chan)
> > +{
> > +    struct tegra_hsp_channel *channel = chan->con_priv;
> > +
> > +    switch (channel->type) {
> > +    case TEGRA_HSP_MBOX_TYPE_DB:
> > +        return tegra_hsp_doorbell_startup(channel_to_doorbell(channel));
> > +    }
> > +
> > +    return -EINVAL;
> > +}
> > +
> > +static void tegra_hsp_shutdown(struct mbox_chan *chan)
> > +{
> > +    struct tegra_hsp_channel *channel = chan->con_priv;
> > +
> > +    switch (channel->type) {
> > +    case TEGRA_HSP_MBOX_TYPE_DB:
> > +        tegra_hsp_doorbell_shutdown(channel_to_doorbell(channel));
> > +        break;
> > +    }
> > +}
> > +
> > +static const struct mbox_chan_ops tegra_hsp_ops = {
> > +    .send_data = tegra_hsp_send_data,
> > +    .startup = tegra_hsp_startup,
> > +    .shutdown = tegra_hsp_shutdown,
> >   };
> > -static struct mbox_chan *of_tegra_hsp_xlate(struct mbox_controller 
> > *mbox,
> > -                        const struct of_phandle_args *args)
> > +static struct mbox_chan *tegra_hsp_doorbell_xlate(struct tegra_hsp *hsp,
> > +                          unsigned int master)
> >   {
> >       struct tegra_hsp_channel *channel = ERR_PTR(-ENODEV);
> > -    struct tegra_hsp *hsp = to_tegra_hsp(mbox);
> > -    unsigned int type = args->args[0];
> > -    unsigned int master = args->args[1];
> >       struct tegra_hsp_doorbell *db;
> >       struct mbox_chan *chan;
> >       unsigned long flags;
> >       unsigned int i;
> > -    switch (type) {
> > -    case TEGRA_HSP_MBOX_TYPE_DB:
> > -        db = tegra_hsp_doorbell_get(hsp, master);
> > -        if (db)
> > -            channel = &db->channel;
> > -
> > -        break;
> > -
> > -    default:
> > -        break;
> > -    }
> > +    db = tegra_hsp_doorbell_get(hsp, master);
> > +    if (db)
> > +        channel = &db->channel;
> >       if (IS_ERR(channel))
> >           return ERR_CAST(channel);
> > @@ -321,6 +343,7 @@ static struct mbox_chan *of_tegra_hsp_xlate(struct 
> > mbox_controller *mbox,
> >           if (!chan->con_priv) {
> >               chan->con_priv = channel;
> >               channel->chan = chan;
> > +            channel->type = TEGRA_HSP_MBOX_TYPE_DB;
> >               break;
>
> I see that you are making the above only used for doorbells, but don't 
> we still need to set the chan->con_priv for shared mailboxes as well?

That's done elsewhere in the next patch that actually adds the shared 
mailbox support.

> Cheers
> Jon

Thanks,
Mikko
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