diff mbox series

[RESEND,4/5] soc: mediatek: mtk-cmdq: Add cmdq_pkt_acquire_event() function

Message ID 20240301144403.2977-5-jason-jh.lin@mediatek.com
State New
Headers
Series Add CMDQ API for upcoming ISP feature |

Commit Message

Jason-JH Lin (林睿祥) March 1, 2024, 2:44 p.m. UTC 
  Add cmdq_pkt_acquire_event() function to support CMDQ user making
an instruction for acquiring event.

CMDQ users can use cmdq_pkt_acquire_event() and cmdq_pkt_clear_event()
to acquire GCE event and release GCE event and achieve the MUTEX_LOCK
protection between GCE threads.

Signed-off-by: Jason-JH.Lin <jason-jh.lin@mediatek.com>
---
 drivers/soc/mediatek/mtk-cmdq-helper.c | 15 +++++++++++++++
 include/linux/soc/mediatek/mtk-cmdq.h  |  9 +++++++++
 2 files changed, 24 insertions(+)

Comments

CK Hu (胡俊光) March 4, 2024, 2:11 a.m. UTC | #1 
Hi, Jason:

On Fri, 2024-03-01 at 22:44 +0800, Jason-JH.Lin wrote:
> Add cmdq_pkt_acquire_event() function to support CMDQ user making
> an instruction for acquiring event.
> 
> CMDQ users can use cmdq_pkt_acquire_event() and
> cmdq_pkt_clear_event()
> to acquire GCE event and release GCE event and achieve the MUTEX_LOCK
> protection between GCE threads.

I'm not clear what acquire do in detail. This is what I guess:

cmdq_pkt_acquire_event() would wait for event to be cleared. After
event is cleared, cmdq_pkt_acquire_event() would set event and keep
executing next command. So the mutex would work like this

cmdq_pkt_acquire_event() /* mutex lock */

/* critical secton */

cmdq_pkt_clear_event() /* mutex unlock */

If it's so, describe as detail as this. If not, describe how it do.

As I know, GCE is single core, so multiple thread is served by single
GCE, why need mutex lock?

Regards,
CK

> 
> Signed-off-by: Jason-JH.Lin <jason-jh.lin@mediatek.com>
> ---
>  drivers/soc/mediatek/mtk-cmdq-helper.c | 15 +++++++++++++++
>  include/linux/soc/mediatek/mtk-cmdq.h  |  9 +++++++++
>  2 files changed, 24 insertions(+)
> 
> diff --git a/drivers/soc/mediatek/mtk-cmdq-helper.c
> b/drivers/soc/mediatek/mtk-cmdq-helper.c
> index 2e9fc9bb1183..0183b40a0eff 100644
> --- a/drivers/soc/mediatek/mtk-cmdq-helper.c
> +++ b/drivers/soc/mediatek/mtk-cmdq-helper.c
> @@ -342,6 +342,21 @@ int cmdq_pkt_wfe(struct cmdq_pkt *pkt, u16
> event, bool clear)
>  }
>  EXPORT_SYMBOL(cmdq_pkt_wfe);
>  
> +int cmdq_pkt_acquire_event(struct cmdq_pkt *pkt, u16 event)
> +{
> +	struct cmdq_instruction inst = {};
> +
> +	if (event >= CMDQ_MAX_EVENT)
> +		return -EINVAL;
> +
> +	inst.op = CMDQ_CODE_WFE;
> +	inst.value = CMDQ_WFE_UPDATE | CMDQ_WFE_UPDATE_VALUE |
> CMDQ_WFE_WAIT;
> +	inst.event = event;
> +
> +	return cmdq_pkt_append_command(pkt, inst);
> +}
> +EXPORT_SYMBOL(cmdq_pkt_acquire_event);
> +
>  int cmdq_pkt_clear_event(struct cmdq_pkt *pkt, u16 event)
>  {
>  	struct cmdq_instruction inst = { {0} };
> diff --git a/include/linux/soc/mediatek/mtk-cmdq.h
> b/include/linux/soc/mediatek/mtk-cmdq.h
> index 2fe9be240fbc..de93c0a8e8a9 100644
> --- a/include/linux/soc/mediatek/mtk-cmdq.h
> +++ b/include/linux/soc/mediatek/mtk-cmdq.h
> @@ -202,6 +202,15 @@ int cmdq_pkt_mem_move(struct cmdq_pkt *pkt,
> dma_addr_t src_addr, dma_addr_t dst_
>   */
>  int cmdq_pkt_wfe(struct cmdq_pkt *pkt, u16 event, bool clear);
>  
> +/**
> + * cmdq_pkt_acquire_event() - append acquire event command to the
> CMDQ packet
> + * @pkt:	the CMDQ packet
> + * @event:	the desired event to be acquired
> + *
> + * Return: 0 for success; else the error code is returned
> + */
> +int cmdq_pkt_acquire_event(struct cmdq_pkt *pkt, u16 event);
> +
>  /**
>   * cmdq_pkt_clear_event() - append clear event command to the CMDQ
> packet
>   * @pkt:	the CMDQ packet
Jason-JH Lin (林睿祥) March 4, 2024, 3:39 p.m. UTC | #2 
Hi CK,

Thanks for the reviews.

On Mon, 2024-03-04 at 02:11 +0000, CK Hu (胡俊光) wrote:
> Hi, Jason:
> 
> On Fri, 2024-03-01 at 22:44 +0800, Jason-JH.Lin wrote:
> > Add cmdq_pkt_acquire_event() function to support CMDQ user making
> > an instruction for acquiring event.
> > 
> > CMDQ users can use cmdq_pkt_acquire_event() and
> > cmdq_pkt_clear_event()
> > to acquire GCE event and release GCE event and achieve the
> > MUTEX_LOCK
> > protection between GCE threads.
> 
> I'm not clear what acquire do in detail. This is what I guess:
> 
> cmdq_pkt_acquire_event() would wait for event to be cleared. After
> event is cleared, cmdq_pkt_acquire_event() would set event and keep
> executing next command. So the mutex would work like this
> 
> cmdq_pkt_acquire_event() /* mutex lock */
> 
> /* critical secton */
> 
> cmdq_pkt_clear_event() /* mutex unlock */
> 
> If it's so, describe as detail as this. If not, describe how it do.
> 
Yes, they should be used like this.
I'll add more description in commit message.

> As I know, GCE is single core, so multiple thread is served by single
> GCE, why need mutex lock?
> 
Although GCE is single core, it will context switch to other GCE
threads with the same priority. The context switch time is set to
GCE_THR_SLOT_CYCLES during GCE initialization.

So we have to use event_lock to protect HW resource if each cmdq_pkt in
different thread may execute more than the context switch time.

Regards,
Jason-JH.Lin

> Regards,
> CK
> 
> > 
> > Signed-off-by: Jason-JH.Lin <jason-jh.lin@mediatek.com>
> > ---
> >  drivers/soc/mediatek/mtk-cmdq-helper.c | 15 +++++++++++++++
> >  include/linux/soc/mediatek/mtk-cmdq.h  |  9 +++++++++
> >  2 files changed, 24 insertions(+)
> > 
> > diff --git a/drivers/soc/mediatek/mtk-cmdq-helper.c
> > b/drivers/soc/mediatek/mtk-cmdq-helper.c
> > index 2e9fc9bb1183..0183b40a0eff 100644
> > --- a/drivers/soc/mediatek/mtk-cmdq-helper.c
> > +++ b/drivers/soc/mediatek/mtk-cmdq-helper.c
> > @@ -342,6 +342,21 @@ int cmdq_pkt_wfe(struct cmdq_pkt *pkt, u16
> > event, bool clear)
> >  }
> >  EXPORT_SYMBOL(cmdq_pkt_wfe);
> >  
> > +int cmdq_pkt_acquire_event(struct cmdq_pkt *pkt, u16 event)
> > +{
> > +	struct cmdq_instruction inst = {};
> > +
> > +	if (event >= CMDQ_MAX_EVENT)
> > +		return -EINVAL;
> > +
> > +	inst.op = CMDQ_CODE_WFE;
> > +	inst.value = CMDQ_WFE_UPDATE | CMDQ_WFE_UPDATE_VALUE |
> > CMDQ_WFE_WAIT;
> > +	inst.event = event;
> > +
> > +	return cmdq_pkt_append_command(pkt, inst);
> > +}
> > +EXPORT_SYMBOL(cmdq_pkt_acquire_event);
> > +
> >  int cmdq_pkt_clear_event(struct cmdq_pkt *pkt, u16 event)
> >  {
> >  	struct cmdq_instruction inst = { {0} };
> > diff --git a/include/linux/soc/mediatek/mtk-cmdq.h
> > b/include/linux/soc/mediatek/mtk-cmdq.h
> > index 2fe9be240fbc..de93c0a8e8a9 100644
> > --- a/include/linux/soc/mediatek/mtk-cmdq.h
> > +++ b/include/linux/soc/mediatek/mtk-cmdq.h
> > @@ -202,6 +202,15 @@ int cmdq_pkt_mem_move(struct cmdq_pkt *pkt,
> > dma_addr_t src_addr, dma_addr_t dst_
> >   */
> >  int cmdq_pkt_wfe(struct cmdq_pkt *pkt, u16 event, bool clear);
> >  
> > +/**
> > + * cmdq_pkt_acquire_event() - append acquire event command to the
> > CMDQ packet
> > + * @pkt:	the CMDQ packet
> > + * @event:	the desired event to be acquired
> > + *
> > + * Return: 0 for success; else the error code is returned
> > + */
> > +int cmdq_pkt_acquire_event(struct cmdq_pkt *pkt, u16 event);
> > +
> >  /**
> >   * cmdq_pkt_clear_event() - append clear event command to the CMDQ
> > packet
> >   * @pkt:	the CMDQ packet
diff mbox series

Patch

diff --git a/drivers/soc/mediatek/mtk-cmdq-helper.c b/drivers/soc/mediatek/mtk-cmdq-helper.c
index 2e9fc9bb1183..0183b40a0eff 100644
--- a/drivers/soc/mediatek/mtk-cmdq-helper.c
+++ b/drivers/soc/mediatek/mtk-cmdq-helper.c
@@ -342,6 +342,21 @@  int cmdq_pkt_wfe(struct cmdq_pkt *pkt, u16 event, bool clear)
 }
 EXPORT_SYMBOL(cmdq_pkt_wfe);
 
+int cmdq_pkt_acquire_event(struct cmdq_pkt *pkt, u16 event)
+{
+	struct cmdq_instruction inst = {};
+
+	if (event >= CMDQ_MAX_EVENT)
+		return -EINVAL;
+
+	inst.op = CMDQ_CODE_WFE;
+	inst.value = CMDQ_WFE_UPDATE | CMDQ_WFE_UPDATE_VALUE | CMDQ_WFE_WAIT;
+	inst.event = event;
+
+	return cmdq_pkt_append_command(pkt, inst);
+}
+EXPORT_SYMBOL(cmdq_pkt_acquire_event);
+
 int cmdq_pkt_clear_event(struct cmdq_pkt *pkt, u16 event)
 {
 	struct cmdq_instruction inst = { {0} };
diff --git a/include/linux/soc/mediatek/mtk-cmdq.h b/include/linux/soc/mediatek/mtk-cmdq.h
index 2fe9be240fbc..de93c0a8e8a9 100644
--- a/include/linux/soc/mediatek/mtk-cmdq.h
+++ b/include/linux/soc/mediatek/mtk-cmdq.h
@@ -202,6 +202,15 @@  int cmdq_pkt_mem_move(struct cmdq_pkt *pkt, dma_addr_t src_addr, dma_addr_t dst_
  */
 int cmdq_pkt_wfe(struct cmdq_pkt *pkt, u16 event, bool clear);
 
+/**
+ * cmdq_pkt_acquire_event() - append acquire event command to the CMDQ packet
+ * @pkt:	the CMDQ packet
+ * @event:	the desired event to be acquired
+ *
+ * Return: 0 for success; else the error code is returned
+ */
+int cmdq_pkt_acquire_event(struct cmdq_pkt *pkt, u16 event);
+
 /**
  * cmdq_pkt_clear_event() - append clear event command to the CMDQ packet
  * @pkt:	the CMDQ packet