Thread (61 messages) 61 messages, 8 authors, 2022-12-05
STALE1285d

[RFC PATCH net-next 05/19] pds_core: Add adminq processing and commands

From: Shannon Nelson <hidden>
Date: 2022-11-18 23:13:49
Subsystem: amd pds core driver, networking drivers, pensando ethernet drivers, the rest · Maintainers: Brett Creeley, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds

Add the service routines for submitting and processing
the adminq messages and for handling notifyq events.

Signed-off-by: Shannon Nelson <redacted>
---
 .../net/ethernet/pensando/pds_core/Makefile   |   1 +
 .../net/ethernet/pensando/pds_core/adminq.c   | 282 ++++++++++++++++++
 drivers/net/ethernet/pensando/pds_core/core.c |  11 -
 drivers/net/ethernet/pensando/pds_core/core.h |   6 +
 include/linux/pds/pds_adminq.h                |   2 +
 5 files changed, 291 insertions(+), 11 deletions(-)
 create mode 100644 drivers/net/ethernet/pensando/pds_core/adminq.c
diff --git a/drivers/net/ethernet/pensando/pds_core/Makefile b/drivers/net/ethernet/pensando/pds_core/Makefile
index 446054206b6a..c7a722f7d9b8 100644
--- a/drivers/net/ethernet/pensando/pds_core/Makefile
+++ b/drivers/net/ethernet/pensando/pds_core/Makefile
@@ -6,6 +6,7 @@ obj-$(CONFIG_PDS_CORE) := pds_core.o
 pds_core-y := main.o \
 	      devlink.o \
 	      dev.o \
+	      adminq.o \
 	      core.o
 
 pds_core-$(CONFIG_DEBUG_FS) += debugfs.o
diff --git a/drivers/net/ethernet/pensando/pds_core/adminq.c b/drivers/net/ethernet/pensando/pds_core/adminq.c
new file mode 100644
index 000000000000..ba9e84a7ca92
--- /dev/null
+++ b/drivers/net/ethernet/pensando/pds_core/adminq.c
@@ -0,0 +1,282 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright(c) 2022 Pensando Systems, Inc */
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/pci.h>
+
+#include "core.h"
+
+#include <linux/pds/pds_adminq.h>
+
+struct pdsc_wait_context {
+	struct pdsc_qcq *qcq;
+	struct completion wait_completion;
+};
+
+static int pdsc_process_notifyq(struct pdsc_qcq *qcq)
+{
+	union pds_core_notifyq_comp *comp;
+	struct pdsc *pdsc = qcq->pdsc;
+	struct pdsc_cq *cq = &qcq->cq;
+	struct pdsc_cq_info *cq_info;
+	int nq_work = 0;
+	u64 eid;
+
+	cq_info = &cq->info[cq->tail_idx];
+	comp = cq_info->comp;
+	eid = le64_to_cpu(comp->event.eid);
+	while (eid > pdsc->last_eid) {
+		u16 ecode = le16_to_cpu(comp->event.ecode);
+
+		switch (ecode) {
+		case PDS_EVENT_LINK_CHANGE:
+			dev_info(pdsc->dev, "NotifyQ LINK_CHANGE ecode %d eid %lld\n",
+				 ecode, eid);
+			break;
+
+		case PDS_EVENT_RESET:
+			dev_info(pdsc->dev, "NotifyQ RESET ecode %d eid %lld\n",
+				 ecode, eid);
+			break;
+
+		case PDS_EVENT_XCVR:
+			dev_info(pdsc->dev, "NotifyQ XCVR ecode %d eid %lld\n",
+				 ecode, eid);
+			break;
+
+		default:
+			dev_info(pdsc->dev, "NotifyQ ecode %d eid %lld\n",
+				 ecode, eid);
+			break;
+		}
+
+		pdsc->last_eid = eid;
+		cq->tail_idx = (cq->tail_idx + 1) & (cq->num_descs - 1);
+		cq_info = &cq->info[cq->tail_idx];
+		comp = cq_info->comp;
+		eid = le64_to_cpu(comp->event.eid);
+
+		nq_work++;
+	}
+
+	qcq->accum_work += nq_work;
+
+	return nq_work;
+}
+
+void pdsc_process_adminq(struct pdsc_qcq *qcq)
+{
+	union pds_core_adminq_comp *comp;
+	struct pdsc_queue *q = &qcq->q;
+	struct pdsc *pdsc = qcq->pdsc;
+	struct pdsc_cq *cq = &qcq->cq;
+	struct pdsc_q_info *q_info;
+	unsigned long irqflags;
+	int nq_work = 0;
+	int aq_work = 0;
+	int credits;
+	u32 index;
+
+	/* Check for NotifyQ event */
+	nq_work = pdsc_process_notifyq(&pdsc->notifyqcq);
+
+	/* Check for empty queue, which can happen if the interrupt was
+	 * for a NotifyQ event and there are no new AdminQ completions.
+	 */
+	if (q->tail_idx == q->head_idx)
+		goto credits;
+
+	/* Find the first completion to clean,
+	 * run the callback in the related q_info,
+	 * and continue while we still match done color
+	 */
+	spin_lock_irqsave(&pdsc->adminq_lock, irqflags);
+	comp = cq->info[cq->tail_idx].comp;
+	while (pdsc_color_match(comp->color, cq->done_color)) {
+		q_info = &q->info[q->tail_idx];
+		index = q->tail_idx;
+		q->tail_idx = (q->tail_idx + 1) & (q->num_descs - 1);
+
+		/* Copy out the completion data */
+		memcpy(q_info->dest, comp, sizeof(*comp));
+
+		complete_all(&q_info->wc->wait_completion);
+
+		if (cq->tail_idx == cq->num_descs - 1)
+			cq->done_color = !cq->done_color;
+		cq->tail_idx = (cq->tail_idx + 1) & (cq->num_descs - 1);
+		comp = cq->info[cq->tail_idx].comp;
+
+		aq_work++;
+	}
+	spin_unlock_irqrestore(&pdsc->adminq_lock, irqflags);
+
+	qcq->accum_work += aq_work;
+
+credits:
+	/* Return the interrupt credits, one for each completion */
+	credits = nq_work + aq_work;
+	if (credits)
+		pds_core_intr_credits(&pdsc->intr_ctrl[qcq->intx],
+				      credits,
+				      PDS_CORE_INTR_CRED_REARM);
+}
+
+void pdsc_work_thread(struct work_struct *work)
+{
+	struct pdsc_qcq *qcq = container_of(work, struct pdsc_qcq, work);
+
+	pdsc_process_adminq(qcq);
+}
+
+irqreturn_t pdsc_adminq_isr(int irq, void *data)
+{
+	struct pdsc_qcq *qcq = data;
+	struct pdsc *pdsc = qcq->pdsc;
+
+	/* Don't process AdminQ when shutting down */
+	if (pdsc->state & BIT_ULL(PDSC_S_STOPPING_DRIVER)) {
+		pr_err("%s: called while PDSC_S_STOPPING_DRIVER\n", __func__);
+		return IRQ_HANDLED;
+	}
+
+	queue_work(pdsc->wq, &qcq->work);
+	pds_core_intr_mask(&pdsc->intr_ctrl[irq], PDS_CORE_INTR_MASK_CLEAR);
+
+	return IRQ_HANDLED;
+}
+
+static int __pdsc_adminq_post(struct pdsc *pdsc,
+			      struct pdsc_qcq *qcq,
+			      union pds_core_adminq_cmd *cmd,
+			      union pds_core_adminq_comp *comp,
+			      struct pdsc_wait_context *wc)
+{
+	struct pdsc_queue *q = &qcq->q;
+	struct pdsc_q_info *q_info;
+	unsigned long irqflags;
+	unsigned int avail;
+	int ret = 0;
+	int index;
+
+	spin_lock_irqsave(&pdsc->adminq_lock, irqflags);
+
+	/* Check for space in the queue */
+	avail = q->tail_idx;
+	if (q->head_idx >= avail)
+		avail += q->num_descs - q->head_idx - 1;
+	else
+		avail -= q->head_idx + 1;
+	if (!avail) {
+		ret = -ENOSPC;
+		goto err_out;
+	}
+
+	/* Check that the FW is running */
+	if (!pdsc_is_fw_running(pdsc)) {
+		u8 fw_status = ioread8(&pdsc->info_regs->fw_status);
+
+		dev_info(pdsc->dev, "%s: post failed - fw not running %#02x:\n",
+			 __func__, fw_status);
+		ret = -ENXIO;
+
+		goto err_out;
+	}
+
+	/* Post the request */
+	index = q->head_idx;
+	q_info = &q->info[index];
+	q_info->wc = wc;
+	q_info->dest = comp;
+	memcpy(q_info->desc, cmd, sizeof(*cmd));
+
+	dev_dbg(pdsc->dev, "head_idx %d tail_idx %d\n", q->head_idx, q->tail_idx);
+	dev_dbg(pdsc->dev, "post admin queue command:\n");
+	dynamic_hex_dump("cmd ", DUMP_PREFIX_OFFSET, 16, 1,
+			 cmd, sizeof(*cmd), true);
+
+	q->head_idx = (q->head_idx + 1) & (q->num_descs - 1);
+
+	pds_core_dbell_ring(pdsc->kern_dbpage, q->hw_type, q->dbval | q->head_idx);
+	ret = index;
+
+err_out:
+	spin_unlock_irqrestore(&pdsc->adminq_lock, irqflags);
+	return ret;
+}
+
+int pdsc_adminq_post(struct pdsc *pdsc,
+		     struct pdsc_qcq *qcq,
+		     union pds_core_adminq_cmd *cmd,
+		     union pds_core_adminq_comp *comp,
+		     bool fast_poll)
+{
+	struct pdsc_wait_context wc = {
+		.wait_completion = COMPLETION_INITIALIZER_ONSTACK(wc.wait_completion),
+		.qcq = qcq,
+	};
+	unsigned long poll_interval = 1;
+	unsigned long time_limit;
+	unsigned long time_start;
+	unsigned long time_done;
+	unsigned long remaining;
+	int err = 0;
+	int index;
+
+	index = __pdsc_adminq_post(pdsc, qcq, cmd, comp, &wc);
+	if (index < 0) {
+		err = index;
+		goto out;
+	}
+
+	time_start = jiffies;
+	time_limit = time_start + HZ * pdsc->devcmd_timeout;
+	do {
+		/* Timeslice the actual wait to catch IO errors etc early */
+		remaining = wait_for_completion_timeout(&wc.wait_completion,
+							msecs_to_jiffies(poll_interval));
+		if (remaining)
+			break;
+
+		if (!pdsc_is_fw_running(pdsc)) {
+			u8 fw_status = ioread8(&pdsc->info_regs->fw_status);
+
+			dev_dbg(pdsc->dev, "%s: post wait failed - fw not running %#02x:\n",
+				__func__, fw_status);
+			err = -ENXIO;
+			break;
+		}
+
+		/* When fast_poll is not requested, prevent aggressive polling
+		 * on failures due to timeouts by doing exponential back off.
+		 */
+		if (!fast_poll && poll_interval < PDSC_ADMINQ_MAX_POLL_INTERVAL)
+			poll_interval <<= 1;
+	} while (time_before(jiffies, time_limit));
+	time_done = jiffies;
+	dev_dbg(pdsc->dev, "%s: elapsed %d msecs\n",
+		__func__, jiffies_to_msecs(time_done - time_start));
+
+	/* Check the results */
+	if (time_after_eq(time_done, time_limit))
+		err = -ETIMEDOUT;
+
+	dev_dbg(pdsc->dev, "read admin queue completion idx %d:\n", index);
+	dynamic_hex_dump("comp ", DUMP_PREFIX_OFFSET, 16, 1,
+			 comp, sizeof(*comp), true);
+
+	if (remaining && comp->status)
+		err = pdsc_err_to_errno(comp->status);
+
+out:
+	if (err) {
+		dev_dbg(pdsc->dev, "%s: opcode %d status %d err %pe\n",
+			__func__, cmd->opcode, comp->status, ERR_PTR(err));
+		if (err == -ENXIO || err == -ETIMEDOUT)
+			pdsc_queue_health_check(pdsc);
+	}
+
+	return err;
+}
diff --git a/drivers/net/ethernet/pensando/pds_core/core.c b/drivers/net/ethernet/pensando/pds_core/core.c
index 507f718bc8ab..e2017cee8284 100644
--- a/drivers/net/ethernet/pensando/pds_core/core.c
+++ b/drivers/net/ethernet/pensando/pds_core/core.c
@@ -12,17 +12,6 @@
 
 #include <linux/pds/pds_adminq.h>
 
-void pdsc_work_thread(struct work_struct *work)
-{
-	/* stub */
-}
-
-irqreturn_t pdsc_adminq_isr(int irq, void *data)
-{
-	/* stub */
-	return IRQ_HANDLED;
-}
-
 void pdsc_intr_free(struct pdsc *pdsc, int index)
 {
 	struct pdsc_intr_info *intr_info;
diff --git a/drivers/net/ethernet/pensando/pds_core/core.h b/drivers/net/ethernet/pensando/pds_core/core.h
index 6b816b7fb193..87b221aa7b44 100644
--- a/drivers/net/ethernet/pensando/pds_core/core.h
+++ b/drivers/net/ethernet/pensando/pds_core/core.h
@@ -263,6 +263,12 @@ int pds_devcmd_vf_start(struct pdsc *pdsc);
 int pdsc_dev_reinit(struct pdsc *pdsc);
 int pdsc_dev_init(struct pdsc *pdsc);
 
+int pdsc_adminq_post(struct pdsc *pdsc,
+		     struct pdsc_qcq *qcq,
+		     union pds_core_adminq_cmd *cmd,
+		     union pds_core_adminq_comp *comp,
+		     bool fast_poll);
+
 int pdsc_intr_alloc(struct pdsc *pdsc, char *name,
 		    irq_handler_t handler, void *data);
 void pdsc_intr_free(struct pdsc *pdsc, int index);
diff --git a/include/linux/pds/pds_adminq.h b/include/linux/pds/pds_adminq.h
index b06d28d0f906..19070099eb35 100644
--- a/include/linux/pds/pds_adminq.h
+++ b/include/linux/pds/pds_adminq.h
@@ -4,6 +4,8 @@
 #ifndef _PDS_CORE_ADMINQ_H_
 #define _PDS_CORE_ADMINQ_H_
 
+#define PDSC_ADMINQ_MAX_POLL_INTERVAL	256
+
 enum pds_core_adminq_flags {
 	PDS_AQ_FLAG_FASTPOLL	= BIT(1),	/* poll for completion at 1ms intervals */
 };
-- 
2.17.1
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