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

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Message-ID: <7db4c129-81aa-6f41-1b98-c301d057facf@gmail.com>
Date:   Sun, 20 Aug 2017 19:18:22 +0300
From:   Dmitry Osipenko <digetx@...il.com>
To:     Mikko Perttunen <mperttunen@...dia.com>, thierry.reding@...il.com,
        jonathanh@...dia.com
Cc:     dri-devel@...ts.freedesktop.org, linux-tegra@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/4] gpu: host1x: Enable Tegra186 syncpoint protection

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@...dia.com>
> ---
>  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);

Since protection is never disabled maybe something like
host1x_hw_syncpt_enable_protection() would fit a bit better.

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


-- 
Dmitry