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Message-ID: <20201009123753.GA32363@e119603-lin.cambridge.arm.com>
Date: Fri, 9 Oct 2020 13:37:53 +0100
From: Cristian Marussi <cristian.marussi@....com>
To: Etienne Carriere <etienne.carriere@...aro.org>
Cc: linux-kernel@...r.kernel.org,
"moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE"
<linux-arm-kernel@...ts.infradead.org>,
Sudeep Holla <sudeep.holla@....com>, lukasz.luba@....com,
Jim Quinlan <james.quinlan@...adcom.com>,
Jonathan.Cameron@...wei.com, broonie@...nel.org,
Rob Herring <robh@...nel.org>, satyakim@....qualcomm.com
Subject: Re: [PATCH 1/4] firmware: arm_scmi: Add Voltage Domain Support
On Thu, Oct 08, 2020 at 12:10:25PM +0200, Etienne Carriere wrote:
> Hello Christian,
>
> I faced an issue with this change, see below.
>
Hi Etienne,
thanks for the review.
[snip]
> > +
> > +static int scmi_voltage_descriptors_get(const struct scmi_handle *handle,
> > + struct voltage_info *vinfo)
> > +{
> > + int ret, dom;
> > + struct scmi_xfer *td, *tl;
> > + struct device *dev = handle->dev;
> > + struct scmi_msg_resp_domain_attributes *resp_dom;
> > + struct scmi_msg_resp_describe_levels *resp_levels;
> > +
> > + ret = scmi_xfer_get_init(handle, VOLTAGE_DOMAIN_ATTRIBUTES,
> > + SCMI_PROTOCOL_VOLTAGE, sizeof(__le32),
> > + sizeof(*resp_dom), &td);
> > + if (ret)
> > + return ret;
> > + resp_dom = td->rx.buf;
> > +
> > + ret = scmi_xfer_get_init(handle, VOLTAGE_DESCRIBE_LEVELS,
> > + SCMI_PROTOCOL_VOLTAGE, sizeof(__le64), 0, &tl);
> > + if (ret)
> > + goto outd;
> > + resp_levels = tl->rx.buf;
> > +
> > + for (dom = 0; dom < vinfo->num_domains; dom++) {
> > + u32 desc_index = 0;
> > + u16 num_returned = 0, num_remaining = 0;
> > + struct scmi_msg_cmd_describe_levels *cmd;
> > + struct scmi_voltage_info *v;
> > +
> > + /* Retrieve domain attributes at first ... */
> > + put_unaligned_le32(dom, td->tx.buf);
> > + ret = scmi_do_xfer(handle, td);
> > + if (ret)
> > + continue;
> > +
> > + v = devm_kzalloc(dev, sizeof(*v), GFP_KERNEL);
> > + if (!v) {
> > + ret = -ENOMEM;
> > + break;
> > + }
> > +
> > + v->id = dom;
> > + v->attributes = le32_to_cpu(resp_dom->attr);
> > + strlcpy(v->name, resp_dom->name, SCMI_MAX_STR_SIZE);
> > +
> > + cmd = tl->tx.buf;
> > + cmd->domain_id = cpu_to_le32(v->id);
> > + /* ...then retrieve domain levels descriptions */
> > + do {
> > + u32 flags;
> > + int cnt;
> > +
>
> Here domain_id must be reloaded in the message payload.
>
> + cmd->domain_id = cpu_to_le32(v->id);
>
> When the SCMI shared memory is used as a unique buffer for
> tx and rx messages, cmd refers to the memory storing previous
> message sent on the SCMI channel.
> In the loop we're in, the previous response has scratched
> previous outgoing message including domain_id value hence
> the full message sent to the SCMI server should be reloaded
> before scmi_do_xfer() is called.
>
Ah right.. I forgot you already pointed out this on another thread.
My bad, I'll fix in v2.
Thanks
Cristian
> Regards,
> etienne
>
> > + cmd->level_index = desc_index;
> > + ret = scmi_do_xfer(handle, tl);
> > + if (ret)
> > + break;
> > +
> > + flags = le32_to_cpu(resp_levels->flags);
> > + num_returned = NUM_RETURNED_LEVELS(flags);
> > + num_remaining = NUM_REMAINING_LEVELS(flags);
> > +
> > + /* Allocate space for num_levels if not already done */
> > + if (!v->num_levels) {
> > + ret = scmi_init_voltage_levels(dev, v, flags,
> > + num_returned +
> > + num_remaining);
> > + if (ret)
> > + break;
> > + }
> > +
> > + if (desc_index + num_returned > v->num_levels) {
> > + dev_err(handle->dev,
> > + "No. of voltage levels can't exceed %d",
> > + v->num_levels);
> > + ret = -EINVAL;
> > + break;
> > + }
> > +
> > + for (cnt = 0; cnt < num_returned; cnt++) {
> > + s32 val;
> > +
> > + val =
> > + (s32)le32_to_cpu(resp_levels->voltage[cnt]);
> > + v->levels_uv[desc_index + cnt] = val;
> > + if (!v->negative_volts_allowed && val < 0)
> > + v->negative_volts_allowed = true;
> > + }
> > +
> > + desc_index += num_returned;
> > + /* check both to avoid infinite loop due to buggy fw */
> > + } while (num_returned && num_remaining);
> > +
> > + /*
> > + * Bail out on memory errors, just skip domain on any
> > + * other error.
> > + */
> > + if (!ret)
> > + vinfo->domains[dom] = v;
> > + else if (ret == -ENOMEM)
> > + break;
> > + }
> > +
> > + scmi_xfer_put(handle, tl);
> > +outd:
> > + scmi_xfer_put(handle, td);
> > +
> > + return ret;
> > +}
> > +
> > +static inline int __scmi_voltage_get_u32(const struct scmi_handle *handle,
> > + u8 cmd_id, u32 domain_id, u32 *value)
> > +{
> > + int ret;
> > + struct scmi_xfer *t;
> > + struct voltage_info *vinfo = handle->voltage_priv;
> > +
> > + if (domain_id >= vinfo->num_domains)
> > + return -EINVAL;
> > +
> > + ret = scmi_xfer_get_init(handle, cmd_id,
> > + SCMI_PROTOCOL_VOLTAGE,
> > + sizeof(__le32), 0, &t);
> > + if (ret)
> > + return ret;
> > +
> > + put_unaligned_le32(domain_id, t->tx.buf);
> > + ret = scmi_do_xfer(handle, t);
> > + if (!ret)
> > + *value = get_unaligned_le32(t->rx.buf);
> > +
> > + scmi_xfer_put(handle, t);
> > + return ret;
> > +}
> > +
> > +static int scmi_voltage_config_set(const struct scmi_handle *handle,
> > + u32 domain_id, u32 config)
> > +{
> > + int ret;
> > + struct scmi_xfer *t;
> > + struct voltage_info *vinfo = handle->voltage_priv;
> > + struct scmi_msg_cmd_config_set *cmd;
> > +
> > + if (domain_id >= vinfo->num_domains)
> > + return -EINVAL;
> > +
> > + ret = scmi_xfer_get_init(handle, VOLTAGE_CONFIG_SET,
> > + SCMI_PROTOCOL_VOLTAGE,
> > + sizeof(*cmd), 0, &t);
> > + if (ret)
> > + return ret;
> > +
> > + cmd = t->tx.buf;
> > + cmd->domain_id = cpu_to_le32(domain_id);
> > + cmd->config = cpu_to_le32(config & GENMASK(3, 0));
> > +
> > + ret = scmi_do_xfer(handle, t);
> > +
> > + scmi_xfer_put(handle, t);
> > + return ret;
> > +}
> > +
> > +static int scmi_voltage_config_get(const struct scmi_handle *handle,
> > + u32 domain_id, u32 *config)
> > +{
> > + return __scmi_voltage_get_u32(handle, VOLTAGE_CONFIG_GET,
> > + domain_id, config);
> > +}
> > +
> > +static int scmi_voltage_level_set(const struct scmi_handle *handle,
> > + u32 domain_id, u32 flags, s32 volt_uV)
> > +{
> > + int ret;
> > + struct scmi_xfer *t;
> > + struct voltage_info *vinfo = handle->voltage_priv;
> > + struct scmi_msg_cmd_level_set *cmd;
> > +
> > + if (domain_id >= vinfo->num_domains)
> > + return -EINVAL;
> > +
> > + ret = scmi_xfer_get_init(handle, VOLTAGE_LEVEL_SET,
> > + SCMI_PROTOCOL_VOLTAGE,
> > + sizeof(*cmd), 0, &t);
> > + if (ret)
> > + return ret;
> > +
> > + cmd = t->tx.buf;
> > + cmd->domain_id = cpu_to_le32(domain_id);
> > + cmd->flags = cpu_to_le32(flags);
> > + cmd->voltage_level = cpu_to_le32(volt_uV);
> > +
> > + ret = scmi_do_xfer(handle, t);
> > +
> > + scmi_xfer_put(handle, t);
> > + return ret;
> > +}
> > +
> > +static int scmi_voltage_level_get(const struct scmi_handle *handle,
> > + u32 domain_id, s32 *volt_uV)
> > +{
> > + return __scmi_voltage_get_u32(handle, VOLTAGE_LEVEL_GET,
> > + domain_id, (u32 *)volt_uV);
> > +}
> > +
> > +static const struct scmi_voltage_info *
> > +scmi_voltage_info_get(const struct scmi_handle *handle, u32 domain_id)
> > +{
> > + struct voltage_info *vinfo = handle->voltage_priv;
> > +
> > + if (domain_id >= vinfo->num_domains)
> > + return NULL;
> > +
> > + return vinfo->domains[domain_id];
> > +}
> > +
> > +static int scmi_voltage_domains_num_get(const struct scmi_handle *handle)
> > +{
> > + struct voltage_info *vinfo = handle->voltage_priv;
> > +
> > + return vinfo->num_domains;
> > +}
> > +
> > +static struct scmi_voltage_ops voltage_ops = {
> > + .num_domains_get = scmi_voltage_domains_num_get,
> > + .info_get = scmi_voltage_info_get,
> > + .config_set = scmi_voltage_config_set,
> > + .config_get = scmi_voltage_config_get,
> > + .level_set = scmi_voltage_level_set,
> > + .level_get = scmi_voltage_level_get,
> > +};
> > +
> > +static int scmi_voltage_protocol_init(struct scmi_handle *handle)
> > +{
> > + int ret;
> > + u32 version;
> > + struct voltage_info *vinfo;
> > +
> > + ret = scmi_version_get(handle, SCMI_PROTOCOL_VOLTAGE, &version);
> > + if (ret)
> > + return ret;
> > +
> > + dev_dbg(handle->dev, "Voltage Version %d.%d\n",
> > + PROTOCOL_REV_MAJOR(version), PROTOCOL_REV_MINOR(version));
> > +
> > + vinfo = devm_kzalloc(handle->dev, sizeof(*vinfo), GFP_KERNEL);
> > + if (!vinfo)
> > + return -ENOMEM;
> > + vinfo->version = version;
> > +
> > + ret = scmi_protocol_attributes_get(handle, vinfo);
> > + if (ret)
> > + return ret;
> > +
> > + if (vinfo->num_domains) {
> > + vinfo->domains = devm_kcalloc(handle->dev, vinfo->num_domains,
> > + sizeof(vinfo->domains),
> > + GFP_KERNEL);
> > + if (!vinfo->domains)
> > + return -ENOMEM;
> > + ret = scmi_voltage_descriptors_get(handle, vinfo);
> > + if (ret)
> > + return ret;
> > + } else {
> > + dev_warn(handle->dev, "No Voltage domains found.\n");
> > + }
> > +
> > + handle->voltage_ops = &voltage_ops;
> > + handle->voltage_priv = vinfo;
> > +
> > + return 0;
> > +}
> > +
> > +DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(SCMI_PROTOCOL_VOLTAGE, voltage)
> > diff --git a/include/linux/scmi_protocol.h b/include/linux/scmi_protocol.h
> > index 9cd312a1ff92..032ad9bb2a53 100644
> > --- a/include/linux/scmi_protocol.h
> > +++ b/include/linux/scmi_protocol.h
> > @@ -209,6 +209,64 @@ struct scmi_reset_ops {
> > int (*deassert)(const struct scmi_handle *handle, u32 domain);
> > };
> >
> > +/**
> > + * struct scmi_voltage_info - describe one available SCMI Voltage Domain
> > + *
> > + * @id: the domain ID as advertised by the platform
> > + * @segmented: defines the layout of the entries of array @levels_uv.
> > + * - when True the entries are to be interpreted as triplets,
> > + * each defining a segment representing a range of equally
> > + * space voltages: <lowest_volts>, <highest_volt>, <step_uV>
> > + * - when False the entries simply represent a single discrete
> > + * supported voltage level
> > + * @negative_volts_allowed: True if any of the entries of @levels_uv represent
> > + * a negative voltage.
> > + * @attributes: represents Voltage Domain advertised attributes
> > + * @name: name assigned to the Voltage Domain by platform
> > + * @num_levels: number of total entries in @levels_uv.
> > + * @levels_uv: array of entries describing the available voltage levels for
> > + * this domain.
> > + */
> > +struct scmi_voltage_info {
> > + u32 id;
> > + bool segmented;
> > +#define SCMI_VOLTAGE_SEGMENT_LOW 0
> > +#define SCMI_VOLTAGE_SEGMENT_HIGH 1
> > +#define SCMI_VOLTAGE_SEGMENT_STEP 2
> > + bool negative_volts_allowed;
> > + u32 attributes;
> > + char name[SCMI_MAX_STR_SIZE];
> > + u16 num_levels;
> > + s32 *levels_uv;
> > +};
> > +
> > +/**
> > + * struct scmi_voltage_ops - represents the various operations provided
> > + * by SCMI Voltage Protocol
> > + *
> > + * @num_domains_get: get the count of voltage domains provided by SCMI
> > + * @info_get: get the information of the specified domain
> > + * @config_set: set the config for the specified domain
> > + * @config_get: get the config of the specified domain
> > + * @level_set: set the voltage level for the specified domain
> > + * @level_get: get the voltage level of the specified domain
> > + */
> > +struct scmi_voltage_ops {
> > + int (*num_domains_get)(const struct scmi_handle *handle);
> > + const struct scmi_voltage_info *(*info_get)
> > + (const struct scmi_handle *handle, u32 domain_id);
> > + int (*config_set)(const struct scmi_handle *handle, u32 domain_id,
> > + u32 config);
> > +#define SCMI_VOLTAGE_ARCH_STATE_OFF 0x0
> > +#define SCMI_VOLTAGE_ARCH_STATE_ON 0x7
> > + int (*config_get)(const struct scmi_handle *handle, u32 domain_id,
> > + u32 *config);
> > + int (*level_set)(const struct scmi_handle *handle, u32 domain_id,
> > + u32 flags, s32 volt_uV);
> > + int (*level_get)(const struct scmi_handle *handle, u32 domain_id,
> > + s32 *volt_uV);
> > +};
> > +
> > /**
> > * struct scmi_notify_ops - represents notifications' operations provided by
> > * SCMI core
> > @@ -262,6 +320,7 @@ struct scmi_notify_ops {
> > * @clk_ops: pointer to set of clock protocol operations
> > * @sensor_ops: pointer to set of sensor protocol operations
> > * @reset_ops: pointer to set of reset protocol operations
> > + * @voltage_ops: pointer to set of voltage protocol operations
> > * @notify_ops: pointer to set of notifications related operations
> > * @perf_priv: pointer to private data structure specific to performance
> > * protocol(for internal use only)
> > @@ -273,6 +332,8 @@ struct scmi_notify_ops {
> > * protocol(for internal use only)
> > * @reset_priv: pointer to private data structure specific to reset
> > * protocol(for internal use only)
> > + * @voltage_priv: pointer to private data structure specific to voltage
> > + * protocol(for internal use only)
> > * @notify_priv: pointer to private data structure specific to notifications
> > * (for internal use only)
> > */
> > @@ -284,6 +345,7 @@ struct scmi_handle {
> > const struct scmi_power_ops *power_ops;
> > const struct scmi_sensor_ops *sensor_ops;
> > const struct scmi_reset_ops *reset_ops;
> > + const struct scmi_voltage_ops *voltage_ops;
> > const struct scmi_notify_ops *notify_ops;
> > /* for protocol internal use */
> > void *perf_priv;
> > @@ -291,6 +353,7 @@ struct scmi_handle {
> > void *power_priv;
> > void *sensor_priv;
> > void *reset_priv;
> > + void *voltage_priv;
> > void *notify_priv;
> > void *system_priv;
> > };
> > @@ -303,6 +366,7 @@ enum scmi_std_protocol {
> > SCMI_PROTOCOL_CLOCK = 0x14,
> > SCMI_PROTOCOL_SENSOR = 0x15,
> > SCMI_PROTOCOL_RESET = 0x16,
> > + SCMI_PROTOCOL_VOLTAGE = 0x17,
> > };
> >
> > enum scmi_system_events {
> > --
> > 2.17.1
> >
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