[Skiboot] [PATCH V6 09/21] core/pldm: Implement PLDM requester
Abhishek SIngh Tomar
abhishek at linux.ibm.com
Fri Sep 30 00:37:47 AEST 2022
On Tue, Sep 13, 2022 at 12:26:53PM +0200, Christophe Lombard wrote:
> Implement a way for sending PLDM requests for specific PLDM commands.
>
> Send a PLDM request message. Wait for corresponding response message,
> which once received, is returned to the caller.
>
> If there's data available, return success only if data is a PLDM response
> message that matches instance, pldm_type and command code.
>
> Signed-off-by: Christophe Lombard <clombard at linux.vnet.ibm.com>
Reviewed-by: Abhishek Singh Tomar <abhishek at linux.ibm.com>
> ---
> core/pldm/Makefile.inc | 2 +-
> core/pldm/pldm-mctp.c | 9 +-
> core/pldm/pldm-requester.c | 331 +++++++++++++++++++++++++++++++++++++
> core/pldm/pldm.h | 9 +
> 4 files changed, 349 insertions(+), 2 deletions(-)
> create mode 100644 core/pldm/pldm-requester.c
>
> diff --git a/core/pldm/Makefile.inc b/core/pldm/Makefile.inc
> index dbca102a..a9b3b7e6 100644
> --- a/core/pldm/Makefile.inc
> +++ b/core/pldm/Makefile.inc
> @@ -7,7 +7,7 @@ SUBDIRS += $(PLDM_DIR)
> CPPFLAGS += -I$(SRC)/pldm/libpldm/
> CPPFLAGS += -I$(SRC)/pldm/ibm/libpldm/
>
> -PLDM_OBJS = pldm-mctp.o pldm-responder.o
> +PLDM_OBJS = pldm-mctp.o pldm-responder.o pldm-requester.o
>
> PLDM = $(PLDM_DIR)/built-in.a
> $(PLDM): $(PLDM_OBJS:%=$(PLDM_DIR)/%)
> diff --git a/core/pldm/pldm-mctp.c b/core/pldm/pldm-mctp.c
> index 51dbad0a..c7d7bb3b 100644
> --- a/core/pldm/pldm-mctp.c
> +++ b/core/pldm/pldm-mctp.c
> @@ -76,6 +76,8 @@ static int handle_message_rx(uint8_t eid, const uint8_t *buf, int len)
> }
>
> switch (rx.hdrinf.msg_type) {
> + case PLDM_RESPONSE:
> + return pldm_requester_handle_response(&rx);
> case PLDM_REQUEST:
> return pldm_responder_handle_request(&rx);
> break;
> @@ -120,8 +122,13 @@ int pldm_mctp_init(uint8_t mode)
>
> /* Register mandatory commands we'll respond to */
> rc = pldm_responder_init();
> - if (rc)
> + if (rc) {
> prlog(PR_ERR, "Failed to register mandatory commands\n");
> + goto out;
> + }
> +
> + /* Requester implementation */
> + pldm_requester_init();
>
> out:
> prlog(PR_NOTICE, "%s - done, rc: %d\n", __func__, rc);
> diff --git a/core/pldm/pldm-requester.c b/core/pldm/pldm-requester.c
> new file mode 100644
> index 00000000..412d495a
> --- /dev/null
> +++ b/core/pldm/pldm-requester.c
> @@ -0,0 +1,331 @@
> +// SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
> +// Copyright 2022 IBM Corp.
> +
> +#define pr_fmt(fmt) "PLDM: " fmt
> +
> +#include <cpu.h>
> +#include <stdio.h>
> +#include <string.h>
> +#include <timebase.h>
> +#include <ast.h>
> +#include <pldm/libpldm/utils.h>
> +#include "pldm.h"
> +
> +struct pldm_request {
> + struct list_node link;
> +
> + /* originating request params */
> + int dest;
> + int instance;
> + int cmd_code;
> + int type;
> +
> + /* messages requested */
> + void *request_msg;
> + int request_len;
> +
> + /* timeout handling */
> + struct timer timeout;
> + uint64_t timeout_ms;
> + uint64_t start_time;
> +
> + /* completion callback */
> + void (*complete)(struct pldm_rx_data *rx, void *data);
> + void *complete_data;
> +};
> +
> +struct pldm_response {
> + void **response_msg;
> + size_t *response_len;
> + bool done;
> + int rc;
> +};
> +
> +/* pldm requests queue */
> +static LIST_HEAD(list_pldm_requests);
> +struct lock list_lock;
> +struct timer requests_timer;
> +
> +static struct pldm_request *active_request;
> +
> +static bool matches_request(const struct pldm_rx_data *rx,
> + const struct pldm_request *req)
> +{
> + if (req->instance != rx->hdrinf.instance)
> + return false;
> + if (req->type != rx->hdrinf.pldm_type)
> + return false;
> + if (req->cmd_code != rx->hdrinf.command)
> + return false;
> +
> + return true;
> +}
> +
> +static void send_and_wait_complete(struct pldm_rx_data *rx, void *data)
> +{
> + struct pldm_response *resp = (struct pldm_response *)data;
> + int len;
> +
> + if (rx != NULL) {
> + len = rx->msg_len;
> + *resp->response_len = len;
> + *resp->response_msg = zalloc(len);
> + memcpy(*resp->response_msg, rx->msg, len);
> +
> + resp->rc = OPAL_SUCCESS;
> + } else {
> + *resp->response_len = 0;
> + *resp->response_msg = NULL;
> + resp->rc = OPAL_TIMEOUT;
> + }
> +
> + resp->done = true;
> +}
> +
> +static void handle_response(struct pldm_rx_data *rx)
> +{
> + uint64_t now;
> +
> + if (active_request == NULL) {
> + prlog(PR_ERR, "%s: No active request\n", __func__);
> + return;
> + }
> +
> + /* unactivate the timer */
> + if (rx != NULL)
> + cancel_timer(&active_request->timeout);
> +
> + if (active_request->complete)
> + active_request->complete(rx, active_request->complete_data);
> +
> + now = mftb();
> + prlog(PR_TRACE, "%s: Finished after %ldms, t:%d c:%d i:%d \n",
> + __func__,
> + tb_to_msecs(now - active_request->start_time),
> + active_request->type,
> + active_request->cmd_code,
> + active_request->instance);
> +
> + free(active_request->request_msg);
> + free(active_request);
> + active_request = NULL;
> +}
> +
> +/*
> + * Timeout :(
> + */
> +static void expiry(struct timer *t __unused, void *data, uint64_t now __unused)
> +{
> + struct pldm_request *req = (struct pldm_request *)data;
> +
> + if (active_request == NULL) {
> + prlog(PR_ERR, "request timedout! (active request NULL)\n");
> + return;
> + }
> +
> + prlog(PR_ERR, "request timedout! (active request: t:%d c:%d i:%d)\n",
> + active_request->type,
> + active_request->cmd_code,
> + active_request->instance);
> +
> + prlog(PR_TRACE, "%s: Original request t:%d c:%d i:%d -----\n",
> + __func__, req->type, req->cmd_code, req->instance);
> +
> + /* no data received. Finish the procedure */
> + handle_response(NULL);
> +}
> +
> +/*
> + * Handle PLDM message received from the PLDM terminus over MCTP
> + */
> +int pldm_requester_handle_response(struct pldm_rx_data *rx)
> +{
> + /* check the message received */
> + if (active_request == NULL) {
> + prlog(PR_ERR, "%s: No active request. "
> + "Response received t:%d c:%d i:%d\n",
> + __func__,
> + rx->hdrinf.pldm_type,
> + rx->hdrinf.command,
> + rx->hdrinf.instance);
> + return OPAL_WRONG_STATE;
> + }
> +
> + if (!matches_request(rx, active_request)) {
> + prlog(PR_ERR, "%s: Unexpected response! t:%d c:%d i:%d want %d,%d,%d\n",
> + __func__,
> + rx->hdrinf.pldm_type,
> + rx->hdrinf.command,
> + rx->hdrinf.instance,
> + active_request->type,
> + active_request->cmd_code,
> + active_request->instance
> + );
> + return OPAL_WRONG_STATE;
> + }
> +
> + /* The expected message seems correct */
> + handle_response(rx);
> +
> + return OPAL_SUCCESS;
> +}
> +
> +/*
> + * Send the PLDM request
> + */
> +static void requests_poller(struct timer *t __unused,
> + void *data __unused,
> + uint64_t now __unused)
> +{
> + int rc = OPAL_SUCCESS;
> +
> + lock(&list_lock);
> +
> + /* no new request to handle */
> + if (list_empty(&list_pldm_requests))
> + goto out;
> +
> + /* wait for the end of the processing of the current request */
> + if (active_request)
> + goto out;
> +
> + /* remove the first entry in a list */
> + active_request = list_pop(&list_pldm_requests,
> + struct pldm_request,
> + link);
> +
> + /* Start timer to control a timeout from the PLDM terminus */
> + init_timer(&active_request->timeout, expiry, active_request);
> + schedule_timer(&active_request->timeout,
> + msecs_to_tb(active_request->timeout_ms));
> + active_request->start_time = mftb();
> +
> + /* Send PLDM message over MCTP */
> + prlog(PR_TRACE, "%s: Sending request to BMC t:%d c:%d i:%d -----\n",
> + __func__,
> + active_request->type,
> + active_request->cmd_code,
> + active_request->instance);
> +
> + rc = pldm_mctp_message_tx(active_request->dest,
> + active_request->request_msg,
> + active_request->request_len);
> + if (rc)
> + prlog(PR_ERR, "%s: Error %d while sending request\n",
> + __func__, rc);
> +
> +out:
> + unlock(&list_lock);
> + schedule_timer(&requests_timer, msecs_to_tb(5));
> +}
> +
> +/*
> + * Add PLDM request in the queue
> + */
> +static int queue_request(void *request_msg, int request_len,
> + uint64_t timeout_ms,
> + void (*complete)(struct pldm_rx_data *rx, void *data),
> + void *complete_data)
> +{
> + struct pldm_header_info hdrinf;
> + struct pldm_request *pending;
> +
> + if (unpack_pldm_header(request_msg, &hdrinf)) {
> + prlog(PR_ERR, "%s: error parsing pldm header\n",
> + __func__);
> + return OPAL_PARAMETER;
> + }
> +
> + pending = zalloc(sizeof(struct pldm_request));
> +
> + pending->dest = BMC_EID;
> + pending->instance = hdrinf.instance;
> + pending->type = hdrinf.pldm_type;
> + pending->cmd_code = hdrinf.command;
> + pending->timeout_ms = timeout_ms;
> + pending->request_msg = zalloc(request_len);
> + memcpy(pending->request_msg, request_msg, request_len);
> +
> + pending->request_len = request_len;
> + pending->complete = complete;
> + pending->complete_data = complete_data;
> +
> + /* add an entry at the end of a linked list */
> + lock(&list_lock);
> + prlog(PR_TRACE, "%s: Add request t:%d c:%d i:%d -----\n",
> + __func__,
> + pending->type,
> + pending->cmd_code,
> + pending->instance);
> + list_add_tail(&list_pldm_requests, &pending->link);
> + unlock(&list_lock);
> +
> + return OPAL_SUCCESS;
> +}
> +
> +#define TIMEOUT_MS 8000
> +
> +/*
> + * Queue a PLDM request and don't wait.
> + * When a response is received, call the associated callback.
> + */
> +int pldm_requester_queue(void *request_msg, size_t request_len,
> + void (*complete)(struct pldm_rx_data *rx, void *data),
> + void *complete_data)
> +{
> + int rc = OPAL_SUCCESS;
> +
> + rc = ast_mctp_ready();
> + if (rc) {
> + prlog(PR_ERR, "%s: BMC is not listening (rc: %d)\n",
> + __func__, rc);
> + return rc;
> + }
> +
> + /* Queue PLDM request */
> + rc = queue_request(request_msg, request_len,
> + TIMEOUT_MS, complete,
> + complete_data);
> + if (rc) {
> + prlog(PR_ERR, "%s: Error %d while queuing request\n",
> + __func__, rc);
> + return rc;
> + }
> +
> + return rc;
> +}
> +
> +/*
> + * Queue a PLDM request and spin until we get a response.
> + */
> +int pldm_requester_queue_and_wait(void *request_msg, size_t request_len,
> + void **response_msg, size_t *response_len)
> +{
> + struct pldm_response resp;
> + int rc;
> +
> + memset(&resp, 0, sizeof(resp));
> + resp.response_msg = response_msg;
> + resp.response_len = response_len;
> +
> + rc = pldm_requester_queue(request_msg, request_len,
> + send_and_wait_complete, &resp);
> + if (rc)
> + return rc;
> +
> + /* wait for a response from the BMC */
> + do {
> + time_wait_ms(5);
> + } while (!resp.done);
> +
> + return resp.rc;
> +}
> +
> +void pldm_requester_init(void)
> +{
> + /* lock used to queue and unqueue pldm requests */
> + init_lock(&list_lock);
> +
> + init_timer(&requests_timer, requests_poller, NULL);
> + schedule_timer(&requests_timer, msecs_to_tb(5));
> +}
> diff --git a/core/pldm/pldm.h b/core/pldm/pldm.h
> index 7df413da..fa7a80de 100644
> --- a/core/pldm/pldm.h
> +++ b/core/pldm/pldm.h
> @@ -42,4 +42,13 @@ int pldm_mctp_message_tx(uint8_t dest_id, uint8_t *buf, int len);
> int pldm_responder_handle_request(struct pldm_rx_data *rx);
> int pldm_responder_init(void);
>
> +/* Requester support */
> +int pldm_requester_handle_response(struct pldm_rx_data *rx);
> +int pldm_requester_queue(void *request_msg, size_t request_len,
> + void (*complete)(struct pldm_rx_data *rx, void *data),
> + void *complete_data);
> +int pldm_requester_queue_and_wait(void *request_msg, size_t request_len,
> + void **response_msg, size_t *response_len);
> +void pldm_requester_init(void);
> +
> #endif /* __COREPLDM_H__ */
> --
> 2.37.3
>
> _______________________________________________
> Skiboot mailing list
> Skiboot at lists.ozlabs.org
> https://lists.ozlabs.org/listinfo/skiboot
More information about the Skiboot
mailing list