Re: [PATCH v7 05/10] drivers: qcom: rpmh-rsc: write sleep/wake requests to TCS

[ilina]

On 2018-05-03 15:35, Matthias Kaehlcke wrote:
> Hi Lina,
>
> On Wed, May 02, 2018 at 01:37:44PM -0600, Lina Iyer wrote:
> > Sleep and wake requests are sent when the application processor
> > subsystem of the SoC is entering deep sleep states like in suspend.
> > These requests help lower the system power requirements when the
> > resources are not in use.
> >
> > Sleep and wake requests are written to the TCS slots but are not
> > triggered at the time of writing. The TCS are triggered by the 
> > firmware
> > after the last of the CPUs has executed its WFI. Since these requests
> > may come in different batches of requests, it is the job of this
> > controller driver to find and arrange the requests into the available
> > TCSes.
> >
> > Signed-off-by: Lina Iyer <ilina@xxxxxxxxxxxxxx>
> > Reviewed-by: Evan Green <evgreen@xxxxxxxxxxxx>
> >
> > ---
> >
> > Changes in v7:
> > 	- Bug fix in find_match()
> > ---
> >  drivers/soc/qcom/rpmh-internal.h |   8 +++
> >  drivers/soc/qcom/rpmh-rsc.c      | 118 
> > +++++++++++++++++++++++++++++++
> >  2 files changed, 126 insertions(+)
> >
> > diff --git a/drivers/soc/qcom/rpmh-internal.h 
> > b/drivers/soc/qcom/rpmh-internal.h
> > index d9a21726e568..6e19fe458c31 100644
> > --- a/drivers/soc/qcom/rpmh-internal.h
> > +++ b/drivers/soc/qcom/rpmh-internal.h
> > @@ -14,6 +14,7 @@
> >  #define MAX_CMDS_PER_TCS		16
> >  #define MAX_TCS_PER_TYPE		3
> >  #define MAX_TCS_NR			(MAX_TCS_PER_TYPE * TCS_TYPE_NR)
> > +#define MAX_TCS_SLOTS			(MAX_CMDS_PER_TCS * MAX_TCS_PER_TYPE)
> >  #define RPMH_MAX_CTRLR			2
> >
> >  struct rsc_drv;
> > @@ -30,6 +31,8 @@ struct rsc_drv;
> >   * @ncpt:      number of commands in each TCS
> >   * @lock:      lock for synchronizing this TCS writes
> >   * @req:       requests that are sent from the TCS
> > + * @cmd_cache: flattened cache of cmds in sleep/wake TCS
> > + * @slots:     indicates which of @cmd_addr are occupied
> >   */
> >  struct tcs_group {
> >  	struct rsc_drv *drv;
> > @@ -40,6 +43,8 @@ struct tcs_group {
> >  	int ncpt;
> >  	spinlock_t lock;
> >  	const struct tcs_request *req[MAX_TCS_PER_TYPE];
> > +	u32 *cmd_cache;
> > +	DECLARE_BITMAP(slots, MAX_TCS_SLOTS);
> >  };
> >
> >  /**
> > @@ -69,6 +74,9 @@ struct rsc_drv {
> >  extern struct list_head rsc_drv_list;
> >
> >  int rpmh_rsc_send_data(struct rsc_drv *drv, const struct tcs_request 
> > *msg);
> > +int rpmh_rsc_write_ctrl_data(struct rsc_drv *drv,
> > +			     const struct tcs_request *msg);
> > +int rpmh_rsc_invalidate(struct rsc_drv *drv);
> >
> >  void rpmh_tx_done(const struct tcs_request *msg, int r);
> >
> > diff --git a/drivers/soc/qcom/rpmh-rsc.c b/drivers/soc/qcom/rpmh-rsc.c
> > index 33270b1d5991..4e2144a14c31 100644
> > --- a/drivers/soc/qcom/rpmh-rsc.c
> > +++ b/drivers/soc/qcom/rpmh-rsc.c
> > @@ -113,6 +113,12 @@ static struct tcs_group *get_tcs_for_msg(struct 
> > rsc_drv *drv,
> >  	case RPMH_ACTIVE_ONLY_STATE:
> >  		type = ACTIVE_TCS;
> >  		break;
> > +	case RPMH_WAKE_ONLY_STATE:
> > +		type = WAKE_TCS;
> > +		break;
> > +	case RPMH_SLEEP_STATE:
> > +		type = SLEEP_TCS;
> > +		break;
> >  	default:
> >  		return ERR_PTR(-EINVAL);
> >  	}
> > @@ -353,6 +359,105 @@ int rpmh_rsc_send_data(struct rsc_drv *drv, 
> > const struct tcs_request *msg)
> >  }
> >  EXPORT_SYMBOL(rpmh_rsc_send_data);
> >
> > +static int find_match(const struct tcs_group *tcs, const struct 
> > tcs_cmd *cmd,
> > +		      int len)
> > +{
> > +	int i, j;
> > +
> > +	/* Check for already cached commands */
> > +	for_each_set_bit(i, tcs->slots, MAX_TCS_SLOTS) {
> > +		if (tcs->cmd_cache[i] != cmd[0].addr)
> > +			continue;
> > +		for (j = 0; j < len; j++) {
> > +			if (tcs->cmd_cache[i + j] != cmd[j].addr) {
>
> As mentioned in the review of v6, the code could read memory beyond
> tcs->cmd_cache if 'i + len > ARRAY_SIZE(tcs->cmd_cache)'
Ok. Will add it.

> > +				WARN(1, "Message does not match previous sequence.\n");
> > +				return -EINVAL;
> > +			}
> > +		}
> > +		return i;
> > +	}
> > +
> > +	return -ENODATA;
> > +}
> > +
> > +static int find_slots(struct tcs_group *tcs, const struct tcs_request 
> > *msg,
> > +		      int *tcs_id, int *cmd_id)
>
> The change from m/n => tcs_id/cmd_id in v7 greatly improves
> readability, thanks!
>
> Matthias
>
> PS: Please remember to include reviewers of earlier revisions to cc:
Sure.

Thanks,
Lina