diff options
| -rw-r--r-- | drivers/firmware/arm_scmi/driver.c | 109 | ||||
| -rw-r--r-- | drivers/firmware/arm_scmi/protocols.h | 54 |
2 files changed, 163 insertions, 0 deletions
diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c index ae2fed4af133..c4960fd3df75 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -1148,8 +1148,117 @@ out: return ret; } +/** + * struct scmi_iterator - Iterator descriptor + * @msg: A reference to the message TX buffer; filled by @prepare_message with + * a proper custom command payload for each multi-part command request. + * @resp: A reference to the response RX buffer; used by @update_state and + * @process_response to parse the multi-part replies. + * @t: A reference to the underlying xfer initialized and used transparently by + * the iterator internal routines. + * @ph: A reference to the associated protocol handle to be used. + * @ops: A reference to the custom provided iterator operations. + * @state: The current iterator state; used and updated in turn by the iterators + * internal routines and by the caller-provided @scmi_iterator_ops. + * @priv: A reference to optional private data as provided by the caller and + * passed back to the @@scmi_iterator_ops. + */ +struct scmi_iterator { + void *msg; + void *resp; + struct scmi_xfer *t; + const struct scmi_protocol_handle *ph; + struct scmi_iterator_ops *ops; + struct scmi_iterator_state state; + void *priv; +}; + +static void *scmi_iterator_init(const struct scmi_protocol_handle *ph, + struct scmi_iterator_ops *ops, + unsigned int max_resources, u8 msg_id, + size_t tx_size, void *priv) +{ + int ret; + struct scmi_iterator *i; + + i = devm_kzalloc(ph->dev, sizeof(*i), GFP_KERNEL); + if (!i) + return ERR_PTR(-ENOMEM); + + i->ph = ph; + i->ops = ops; + i->priv = priv; + + ret = ph->xops->xfer_get_init(ph, msg_id, tx_size, 0, &i->t); + if (ret) { + devm_kfree(ph->dev, i); + return ERR_PTR(ret); + } + + i->state.max_resources = max_resources; + i->msg = i->t->tx.buf; + i->resp = i->t->rx.buf; + + return i; +} + +static int scmi_iterator_run(void *iter) +{ + int ret = -EINVAL; + struct scmi_iterator *i = iter; + struct scmi_iterator_state *st = &i->state; + struct scmi_iterator_ops *iops = i->ops; + const struct scmi_protocol_handle *ph = i->ph; + const struct scmi_xfer_ops *xops = ph->xops; + + if (!i) + return ret; + + do { + iops->prepare_message(i->msg, st->desc_index, i->priv); + ret = xops->do_xfer(ph, i->t); + if (ret) + break; + + ret = iops->update_state(st, i->resp, i->priv); + if (ret) + break; + + if (st->num_returned > st->max_resources - st->desc_index) { + dev_err(ph->dev, + "No. of resources can't exceed %d\n", + st->max_resources); + ret = -EINVAL; + break; + } + + for (st->loop_idx = 0; st->loop_idx < st->num_returned; + st->loop_idx++) { + ret = iops->process_response(ph, i->resp, st, i->priv); + if (ret) + goto out; + } + + st->desc_index += st->num_returned; + xops->reset_rx_to_maxsz(ph, i->t); + /* + * check for both returned and remaining to avoid infinite + * loop due to buggy firmware + */ + } while (st->num_returned && st->num_remaining); + +out: + /* Finalize and destroy iterator */ + xops->xfer_put(ph, i->t); + devm_kfree(ph->dev, i); + + return ret; +} + static const struct scmi_proto_helpers_ops helpers_ops = { .extended_name_get = scmi_common_extended_name_get, + .iter_response_init = scmi_iterator_init, + .iter_response_run = scmi_iterator_run, }; /** diff --git a/drivers/firmware/arm_scmi/protocols.h b/drivers/firmware/arm_scmi/protocols.h index 60ea880b3855..73304af5ec4a 100644 --- a/drivers/firmware/arm_scmi/protocols.h +++ b/drivers/firmware/arm_scmi/protocols.h @@ -174,16 +174,70 @@ struct scmi_protocol_handle { }; /** + * struct scmi_iterator_state - Iterator current state descriptor + * @desc_index: Starting index for the current mulit-part request. + * @num_returned: Number of returned items in the last multi-part reply. + * @num_remaining: Number of remaining items in the multi-part message. + * @max_resources: Maximum acceptable number of items, configured by the caller + * depending on the underlying resources that it is querying. + * @loop_idx: The iterator loop index in the current multi-part reply. + * @priv: Optional pointer to some additional state-related private data setup + * by the caller during the iterations. + */ +struct scmi_iterator_state { + unsigned int desc_index; + unsigned int num_returned; + unsigned int num_remaining; + unsigned int max_resources; + unsigned int loop_idx; + void *priv; +}; + +/** + * struct scmi_iterator_ops - Custom iterator operations + * @prepare_message: An operation to provide the custom logic to fill in the + * SCMI command request pointed by @message. @desc_index is + * a reference to the next index to use in the multi-part + * request. + * @update_state: An operation to provide the custom logic to update the + * iterator state from the actual message response. + * @process_response: An operation to provide the custom logic needed to process + * each chunk of the multi-part message. + */ +struct scmi_iterator_ops { + void (*prepare_message)(void *message, unsigned int desc_index, + const void *priv); + int (*update_state)(struct scmi_iterator_state *st, + const void *response, void *priv); + int (*process_response)(const struct scmi_protocol_handle *ph, + const void *response, + struct scmi_iterator_state *st, void *priv); +}; + +/** * struct scmi_proto_helpers_ops - References to common protocol helpers * @extended_name_get: A common helper function to retrieve extended naming * for the specified resource using the specified command. * Result is returned as a NULL terminated string in the * pre-allocated area pointed to by @name with maximum * capacity of @len bytes. + * @iter_response_init: A common helper to initialize a generic iterator to + * parse multi-message responses: when run the iterator + * will take care to send the initial command request as + * specified by @msg_id and @tx_size and then to parse the + * multi-part responses using the custom operations + * provided in @ops. + * @iter_response_run: A common helper to trigger the run of a previously + * initialized iterator. */ struct scmi_proto_helpers_ops { int (*extended_name_get)(const struct scmi_protocol_handle *ph, u8 cmd_id, u32 res_id, char *name, size_t len); + void *(*iter_response_init)(const struct scmi_protocol_handle *ph, + struct scmi_iterator_ops *ops, + unsigned int max_resources, u8 msg_id, + size_t tx_size, void *priv); + int (*iter_response_run)(void *iter); }; /** |