Re: [PATCH 1/4] gpu: host1x: Enable Tegra186 syncpoint protection

[Mikko Perttunen]

On 08/19/2017 01:36 AM, Dmitry Osipenko wrote:
> On 18.08.2017 19:15, Mikko Perttunen wrote:
> > Since Tegra186 the Host1x hardware allows syncpoints to be assigned to
> > specific channels, preventing any other channels from incrementing
> > them.
> >
> > Enable this feature where available and assign syncpoints to channels
> > when submitting a job. Syncpoints are currently never unassigned from
> > channels since that would require extra work and is unnecessary with
> > the current channel allocation model.
> >
> > Signed-off-by: Mikko Perttunen <mperttunen@xxxxxxxxxx>
> > ---
> >   drivers/gpu/host1x/dev.h           | 16 ++++++++++++++++
> >   drivers/gpu/host1x/hw/channel_hw.c |  3 +++
> >   drivers/gpu/host1x/hw/syncpt_hw.c  | 26 ++++++++++++++++++++++++++
> >   drivers/gpu/host1x/syncpt.c        |  3 +++
> >   4 files changed, 48 insertions(+)
> >
> > diff --git a/drivers/gpu/host1x/dev.h b/drivers/gpu/host1x/dev.h
> > index def802c0a6bf..2432a30ff6e2 100644
> > --- a/drivers/gpu/host1x/dev.h
> > +++ b/drivers/gpu/host1x/dev.h
> > @@ -79,6 +79,9 @@ struct host1x_syncpt_ops {
> >   	u32 (*load)(struct host1x_syncpt *syncpt);
> >   	int (*cpu_incr)(struct host1x_syncpt *syncpt);
> >   	int (*patch_wait)(struct host1x_syncpt *syncpt, void *patch_addr);
> > +	void (*assign_channel)(struct host1x_syncpt *syncpt,
> > +	                       struct host1x_channel *channel);
> > +	void (*set_protection)(struct host1x *host, bool enabled);
> >   };
> >   
> >   struct host1x_intr_ops {
> > @@ -186,6 +189,19 @@ static inline int host1x_hw_syncpt_patch_wait(struct host1x *host,
> >   	return host->syncpt_op->patch_wait(sp, patch_addr);
> >   }
> >   
> > +static inline void host1x_hw_syncpt_assign_channel(struct host1x *host,
> > +						   struct host1x_syncpt *sp,
> > +						   struct host1x_channel *ch)
> > +{
> > +	return host->syncpt_op->assign_channel(sp, ch);
> > +}
> > +
> > +static inline void host1x_hw_syncpt_set_protection(struct host1x *host,
> > +						   bool enabled)
> > +{
> > +	return host->syncpt_op->set_protection(host, enabled);
> > +}
> > +
> >   static inline int host1x_hw_intr_init_host_sync(struct host1x *host, u32 cpm,
> >   			void (*syncpt_thresh_work)(struct work_struct *))
> >   {
> > diff --git a/drivers/gpu/host1x/hw/channel_hw.c b/drivers/gpu/host1x/hw/channel_hw.c
> > index 8447a56c41ca..0161da331702 100644
> > --- a/drivers/gpu/host1x/hw/channel_hw.c
> > +++ b/drivers/gpu/host1x/hw/channel_hw.c
> > @@ -147,6 +147,9 @@ static int channel_submit(struct host1x_job *job)
> >   
> >   	syncval = host1x_syncpt_incr_max(sp, user_syncpt_incrs);
> >   
> > +	/* assign syncpoint to channel */
> > +	host1x_hw_syncpt_assign_channel(host, sp, ch);
> > +
> >   	job->syncpt_end = syncval;
> >   
> >   	/* add a setclass for modules that require it */
> > diff --git a/drivers/gpu/host1x/hw/syncpt_hw.c b/drivers/gpu/host1x/hw/syncpt_hw.c
> > index 7b0270d60742..5d117ab1699e 100644
> > --- a/drivers/gpu/host1x/hw/syncpt_hw.c
> > +++ b/drivers/gpu/host1x/hw/syncpt_hw.c
> > @@ -106,6 +106,30 @@ static int syncpt_patch_wait(struct host1x_syncpt *sp, void *patch_addr)
> >   	return 0;
> >   }
> >   
> > +static void syncpt_assign_channel(struct host1x_syncpt *sp,
> > +				  struct host1x_channel *ch)
> > +{
> > +#if HOST1X_HW >= 6
> > +	struct host1x *host = sp->host;
> > +
> > +	if (!host->hv_regs)
> > +		return;
> > +
> > +	host1x_sync_writel(host,
> > +			   HOST1X_SYNC_SYNCPT_CH_APP_CH(ch ? ch->id : 0xff),
> > +			   HOST1X_SYNC_SYNCPT_CH_APP(sp->id));
> > +#endif
> > +}
> > +
> > +static void syncpt_set_protection(struct host1x *host, bool enabled)
> > +{
> > +#if HOST1X_HW >= 6
> > +	host1x_hypervisor_writel(host,
> > +				 enabled ? HOST1X_HV_SYNCPT_PROT_EN_CH_EN : 0,
> > +				 HOST1X_HV_SYNCPT_PROT_EN);
> > +#endif
> > +}
> > +
> >   static const struct host1x_syncpt_ops host1x_syncpt_ops = {
> >   	.restore = syncpt_restore,
> >   	.restore_wait_base = syncpt_restore_wait_base,
> > @@ -113,4 +137,6 @@ static const struct host1x_syncpt_ops host1x_syncpt_ops = {
> >   	.load = syncpt_load,
> >   	.cpu_incr = syncpt_cpu_incr,
> >   	.patch_wait = syncpt_patch_wait,
> > +	.assign_channel = syncpt_assign_channel,
> > +	.set_protection = syncpt_set_protection,
> >   };
> > diff --git a/drivers/gpu/host1x/syncpt.c b/drivers/gpu/host1x/syncpt.c
> > index 048ac9e344ce..fe4d963b3e2a 100644
> > --- a/drivers/gpu/host1x/syncpt.c
> > +++ b/drivers/gpu/host1x/syncpt.c
> > @@ -398,6 +398,8 @@ int host1x_syncpt_init(struct host1x *host)
> >   	for (i = 0; i < host->info->nb_pts; i++) {
> >   		syncpt[i].id = i;
> >   		syncpt[i].host = host;
> > +
> > +		host1x_hw_syncpt_assign_channel(host, &syncpt[i], NULL);
> >   	}
> >   
> >   	for (i = 0; i < host->info->nb_bases; i++)
> > @@ -408,6 +410,7 @@ int host1x_syncpt_init(struct host1x *host)
> >   	host->bases = bases;
> >   
> >   	host1x_syncpt_restore(host);
> > +	host1x_hw_syncpt_set_protection(host, true);
>
> Is it really okay to force the protection? Maybe protection should be enabled
> with a respect to CONFIG_TEGRA_HOST1X_FIREWALL? In that case we would have to
> avoid software jobs validation for Tegra124+.

I don't quite get your comment. The hardware syncpt protection layer 
being enabled should never hurt - it doesn't mess with any valid jobs. 
It's also only on Tegra186 so I'm not sure where the Tegra124 comes from.

Cheers,
Mikko

> >   
> >   	/* Allocate sync point to use for clearing waits for expired fences */
> >   	host->nop_sp = host1x_syncpt_alloc(host, NULL, 0);