Messages in this thread | | | From | Peng Fan <> | Subject | RE: [PATCH V1] firmware: arm_scmi: clock: support clock denied flags | Date | Tue, 31 Oct 2023 13:33:17 +0000 |
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> Subject: Re: [PATCH V1] firmware: arm_scmi: clock: support clock denied > flags > > On Tue, Oct 31, 2023 at 08:27:34PM +0800, Peng Fan (OSS) wrote: > > From: Peng Fan <peng.fan@nxp.com> > > > > The firmware may export flags to indicate whether the clock is allowed > > to set rate, set parent, enable/disable from the Agent. > > > > If Agent is not allowed to enable/disable, directly return success. > > ... even though, this success on deny built-in policy could be > controversial.. Yeah.
.Have you tried the different approach of not registerig the > enable/prepare callbacks in clk-scmi instead ?
Not yet, I could give a look. But not have much time in the following week.
> From the Clk framework code it seems could be handled gracefully. > (I have not tried though...)
If there is no enable/disable/prepare/unprepared hooks, the enable counter or prepare counter would be used.
Thanks, Peng. > > Thanks, > Cristian > > > If Agent is not allowed to set rate/parent, directly return -EACCES to > > avoid SCMI RPC calls. > > > > Signed-off-by: Peng Fan <peng.fan@nxp.com> > > --- > > > > V1: > > drop the changes in clock.c, add an attribute entry in clock info > > which may be easy for extending new flag. > > > > SPEC still not have such support, this is for discussion > > > > drivers/firmware/arm_scmi/clock.c | 19 +++++++++++++++++++ > > include/linux/scmi_protocol.h | 1 + > > 2 files changed, 20 insertions(+) > > > > diff --git a/drivers/firmware/arm_scmi/clock.c > > b/drivers/firmware/arm_scmi/clock.c > > index 42b81c181d68..fad4329a21fc 100644 > > --- a/drivers/firmware/arm_scmi/clock.c > > +++ b/drivers/firmware/arm_scmi/clock.c > > @@ -46,6 +46,9 @@ struct scmi_msg_resp_clock_attributes { > > #define SUPPORTS_RATE_CHANGE_REQUESTED_NOTIF(x) ((x) & > BIT(30)) > > #define SUPPORTS_EXTENDED_NAMES(x) ((x) & BIT(29)) > > #define SUPPORTS_PARENT_CLOCK(x) ((x) & BIT(28)) > > +#define SCMI_CLOCK_SET_ENABLE_DENIED BIT(15) > > +#define SCMI_CLOCK_SET_RATE_DENIED BIT(14) > > +#define SCMI_CLOCK_SET_PARENT_DENIED BIT(13) > > u8 name[SCMI_SHORT_NAME_MAX_SIZE]; > > __le32 clock_enable_latency; > > }; > > @@ -307,6 +310,7 @@ static int scmi_clock_attributes_get(const struct > scmi_protocol_handle *ph, > > if (PROTOCOL_REV_MAJOR(version) >= 0x2) > > latency = le32_to_cpu(attr->clock_enable_latency); > > clk->enable_latency = latency ? : U32_MAX; > > + clk->attributes = attributes; > > } > > > > ph->xops->xfer_put(ph, t); > > @@ -499,6 +503,10 @@ static int scmi_clock_rate_set(const struct > scmi_protocol_handle *ph, > > struct scmi_xfer *t; > > struct scmi_clock_set_rate *cfg; > > struct clock_info *ci = ph->get_priv(ph); > > + struct scmi_clock_info *clk = ci->clk + clk_id; > > + > > + if (clk->attributes & SCMI_CLOCK_SET_RATE_DENIED) > > + return -EACCES; > > > > ret = ph->xops->xfer_get_init(ph, CLOCK_RATE_SET, sizeof(*cfg), 0, > &t); > > if (ret) > > @@ -585,6 +593,9 @@ scmi_clock_set_parent(const struct > scmi_protocol_handle *ph, u32 clk_id, > > if (parent_id >= clk->num_parents) > > return -EINVAL; > > > > + if (clk->attributes & SCMI_CLOCK_SET_PARENT_DENIED) > > + return -EACCES; > > + > > ret = ph->xops->xfer_get_init(ph, CLOCK_PARENT_SET, > > sizeof(*cfg), 0, &t); > > if (ret) > > @@ -668,6 +679,10 @@ static int scmi_clock_enable(const struct > scmi_protocol_handle *ph, u32 clk_id, > > bool atomic) > > { > > struct clock_info *ci = ph->get_priv(ph); > > + struct scmi_clock_info *clk = ci->clk + clk_id; > > + > > + if (clk->attributes & SCMI_CLOCK_SET_ENABLE_DENIED) > > + return 0; > > > > return ci->clock_config_set(ph, clk_id, CLK_STATE_ENABLE, > > NULL_OEM_TYPE, 0, atomic); > > @@ -677,6 +692,10 @@ static int scmi_clock_disable(const struct > scmi_protocol_handle *ph, u32 clk_id, > > bool atomic) > > { > > struct clock_info *ci = ph->get_priv(ph); > > + struct scmi_clock_info *clk = ci->clk + clk_id; > > + > > + if (clk->attributes & SCMI_CLOCK_SET_ENABLE_DENIED) > > + return 0; > > > > return ci->clock_config_set(ph, clk_id, CLK_STATE_DISABLE, > > NULL_OEM_TYPE, 0, atomic); > > diff --git a/include/linux/scmi_protocol.h > > b/include/linux/scmi_protocol.h index f2f05fb42d28..ddf5363c8cfd > > 100644 > > --- a/include/linux/scmi_protocol.h > > +++ b/include/linux/scmi_protocol.h > > @@ -58,6 +58,7 @@ struct scmi_clock_info { > > u64 step_size; > > } range; > > }; > > + u32 attributes; > > int num_parents; > > u32 *parents; > > }; > > -- > > 2.37.1 > >
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