[Skiboot] [PATCH V2 09/21] core/pldm: Implement PLDM requester

Abhishek SIngh Tomar abhishek at linux.ibm.com
Wed Mar 16 20:28:16 AEDT 2022


Hello Christophe

In function queue_request()  we pass eid as argument.

function calling as follows:
queue_request() -> start_req() -> pldm_send() -> ast_mctp_message_tx()

In ast_mctp_message_tx() we pass BMC_EID forcefully but not taking into
consideration queue_request() passed EID. Are both eid corresponds to 
destination?

Regards
Abhishek Singh Tomar

On Fri, Mar 04, 2022 at 02:11:42PM +0100, 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>
> ---
>  core/pldm/Makefile.inc     |   2 +-
>  core/pldm/pldm-common.c    |   2 +
>  core/pldm/pldm-requester.c | 268 +++++++++++++++++++++++++++++++++++++
>  core/pldm/pldm.h           |   6 +
>  4 files changed, 277 insertions(+), 1 deletion(-)
>  create mode 100644 core/pldm/pldm-requester.c
> 
> diff --git a/core/pldm/Makefile.inc b/core/pldm/Makefile.inc
> index 3909c86f..c431288f 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-common.o pldm-responder.o
> +PLDM_OBJS = pldm-common.o pldm-responder.o pldm-requester.o
>  
>  PLDM = $(PLDM_DIR)/built-in.a
>  $(PLDM): $(PLDM_OBJS:%=$(PLDM_DIR)/%)
> diff --git a/core/pldm/pldm-common.c b/core/pldm/pldm-common.c
> index 76cb1aa5..15ee2af9 100644
> --- a/core/pldm/pldm-common.c
> +++ b/core/pldm/pldm-common.c
> @@ -76,6 +76,8 @@ static int pldm_handle(uint8_t eid, const uint8_t *buf, int len)
>  	}
>  
>  	switch (rx.hdrinf.msg_type) {
> +	case PLDM_RESPONSE:
> +		return pldm_rx_handle_response(&rx);
>  	case PLDM_REQUEST:
>  		return pldm_rx_handle_request(&rx);
>  	break;
> diff --git a/core/pldm/pldm-requester.c b/core/pldm/pldm-requester.c
> new file mode 100644
> index 00000000..58d01f80
> --- /dev/null
> +++ b/core/pldm/pldm-requester.c
> @@ -0,0 +1,268 @@
> +// 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 <pldm/libpldm/utils.h>
> +#include "pldm.h"
> +
> +struct pldm_request {
> +	/* originating request params */
> +	int dest;
> +	int instance;
> +	int cmd_code;
> +	int type;
> +
> +	uint64_t timeout_ms;
> +	uint64_t start_time;
> +
> +	void *buf;
> +	int len;
> +
> +	/* completion callback */
> +	void (*complete)(struct pldm_request *req,
> +			 struct pldm_rx_data *resp);
> +	void *cb_data;
> +	int rc;
> +
> +	struct list_node link;
> +};
> +
> +/*
> + * Sent out and waiting on a response.
> + */
> +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;
> +}
> +
> +/*
> + * Requests that are ready to send.
> + */
> +LIST_HEAD(pldm_request_queue);
> +
> +static bool request_timed_out(struct pldm_request *req)
> +{
> +	uint64_t deadline = req->start_time + msecs_to_tb(req->timeout_ms);
> +
> +	return tb_compare(mftb(), deadline) == TB_AAFTERB;
> +}
> +
> +/*
> + * Send the PLDM request.
> + */
> +static void start_req(struct pldm_request *r)
> +{
> +	if (active_request) {
> +		prlog(PR_ERR, "%s: request already active?\n",
> +			      __func__);
> +		return;
> +	}
> +
> +	r->start_time = mftb();
> +	active_request = r;
> +
> +	pldm_send(r->buf, r->len);
> +}
> +
> +static void complete_request(struct pldm_rx_data *rx)
> +{
> +	struct pldm_request *req = active_request;
> +
> +	if (req->complete)
> +		req->complete(req, rx);
> +
> +	active_request = NULL;
> +}
> +
> +/*
> + * Add PLDM request in the queue/
> + */
> +static int queue_request(int dest_eid, void *buf, int len,
> +			 uint64_t timeout_ms,
> +			 void (*complete)(struct pldm_request *,
> +					  struct pldm_rx_data *),
> +			 void *cb_data)
> +{
> +	struct pldm_header_info hdrinf;
> +	struct pldm_request *pending;
> +
> +	if (active_request)
> +		return OPAL_BUSY;
> +
> +	if (unpack_pldm_header(buf, &hdrinf)) {
> +		prlog(PR_ERR, "%s: error parsing pldm header\n",
> +			      __func__);
> +		return OPAL_PARAMETER;
> +	}
> +
> +	pending = zalloc(sizeof(struct pldm_request));
> +
> +	pending->dest		= dest_eid;
> +	pending->instance	= hdrinf.instance;
> +	pending->type		= hdrinf.pldm_type;
> +	pending->cmd_code	= hdrinf.command;
> +	pending->timeout_ms	= timeout_ms;
> +
> +	pending->buf		= buf;
> +	pending->len		= len;
> +
> +	pending->complete	= complete;
> +	pending->cb_data	= cb_data;
> +
> +	start_req(pending);
> +
> +	return OPAL_SUCCESS;
> +}
> +
> +/*
> + * Synchronus request handling.
> + */
> +struct pldm_do_request_data {
> +	void **buf;
> +	size_t *len;
> +	bool done;
> +	int rc;
> +};
> +
> +static void do_request_cb(struct pldm_request *req,
> +			  struct pldm_rx_data *resp)
> +{
> +	struct pldm_do_request_data *cb_data = req->cb_data;
> +	int len = resp->msg_len;
> +
> +	if (resp && !request_timed_out(req)) {
> +		*cb_data->len = len;
> +		*cb_data->buf = malloc(len);
> +		memcpy(*cb_data->buf, resp->msg, len);
> +
> +		cb_data->rc = OPAL_SUCCESS;
> +	} else {
> +		*cb_data->len = 0;
> +		*cb_data->buf = NULL;
> +		cb_data->rc = OPAL_TIMEOUT;
> +	}
> +
> +	cb_data->done = true;
> +
> +	free(req);
> +}
> +
> +/*
> + * Timeout :(
> + */
> +static void pldm_timeout_cb(struct timer *t __unused, void *data,
> +			    uint64_t now __unused)
> +{
> +	struct pldm_do_request_data *cb_data = data;
> +
> +	if (cb_data->done)
> +		return;
> +
> +	prlog(PR_ERR, "%s, request timedout!\n", __func__);
> +	complete_request(NULL);
> +}
> +
> +/*
> + * Send a PLDM request and spin until we get a reply.
> + */
> +int pldm_do_request(uint8_t dest_eid,
> +		    void *request_msg, size_t request_len,
> +		    void **response_msg, size_t *response_len)
> +{
> +	uint64_t now, queue_start, resp_start;
> +	struct pldm_do_request_data cb_data;
> +	struct timer pldm_timeout;
> +	uint64_t timeout_ms;
> +	int retries = 10;
> +	int rc;
> +
> +	/* Start timer ton control a timeout from the PLDM terminus */
> +	init_timer(&pldm_timeout, pldm_timeout_cb, &cb_data);
> +	timeout_ms = 8000;
> +
> +	memset(&cb_data, 0, sizeof(cb_data));
> +	cb_data.buf = response_msg;
> +	cb_data.len = response_len;
> +
> +	/* Send PLDM request */
> +	queue_start = mftb();
> +	do {
> +		rc = queue_request(dest_eid,
> +				   request_msg, request_len,
> +				   timeout_ms, do_request_cb,
> +				   &cb_data);
> +		if (rc == OPAL_BUSY) {
> +			time_wait_ms(10);
> +			retries--;
> +		}
> +		if (!retries) {
> +			prlog(PR_ERR, "%s, timed out trying to queue "
> +				      "PLDM request\n", __func__);
> +			return OPAL_BUSY;
> +		}
> +	} while (rc == OPAL_BUSY);
> +
> +	if (rc) {
> +		prlog(PR_ERR, "%s: Error %d while queuing request\n",
> +			      __func__, rc);
> +		return rc;
> +	}
> +
> +	/* Wait for answer from the PLDM terminus */
> +	schedule_timer(&pldm_timeout, msecs_to_tb(timeout_ms));
> +	resp_start = mftb();
> +	do {
> +		time_wait_ms(5);
> +	} while (!cb_data.done);
> +
> +	cancel_timer(&pldm_timeout);
> +	now = mftb();
> +
> +	prlog(PR_TRACE, "%s: Finished after %ldms, length: %ld "
> +			"(queuing: %ldms, resp: %ldms)\n",
> +			__func__,
> +			tb_to_msecs(now        - queue_start),
> +			*cb_data.len,
> +			tb_to_msecs(resp_start - queue_start),
> +			tb_to_msecs(now        - resp_start));
> +
> +	return cb_data.rc;
> +}
> +
> +/*
> + * Handle PLDM message received from the PLDM terminus over MCTP.
> + */
> +int pldm_rx_handle_response(struct pldm_rx_data *rx)
> +{
> +	/* check the message received */
> +	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;
> +	}
> +
> +	complete_request(rx);
> +	return OPAL_SUCCESS;
> +}
> diff --git a/core/pldm/pldm.h b/core/pldm/pldm.h
> index 74f883d6..fd677742 100644
> --- a/core/pldm/pldm.h
> +++ b/core/pldm/pldm.h
> @@ -46,4 +46,10 @@ void pldm_rx_message(uint8_t eid, void *data __unused, void *vmsg,
>  int pldm_rx_handle_request(struct pldm_rx_data *rx);
>  int pldm_mctp_responder_init(void);
>  
> +/* Requester support */
> +int pldm_do_request(uint8_t dest_eid,
> +		    void *request_msg, size_t request_len,
> +		    void **response_msg, size_t *response_len);
> +int pldm_rx_handle_response(struct pldm_rx_data *rx);
> +
>  #endif /* __COREPLDM_H__ */
> -- 
> 2.35.1
> 
> _______________________________________________
> Skiboot mailing list
> Skiboot at lists.ozlabs.org
> https://lists.ozlabs.org/listinfo/skiboot


More information about the Skiboot mailing list