[GitHub] [incubator-nuttx] gustavonihei commented on a change in pull request #2916: arm/rp2040: Raspberry Pi Pico SMP support

[GitBox <gi...@apache.org>]

gustavonihei commented on a change in pull request #2916:
URL: https://github.com/apache/incubator-nuttx/pull/2916#discussion_r582134246



##########
File path: arch/arm/src/rp2040/rp2040_cpupause.c
##########
@@ -0,0 +1,437 @@
+/****************************************************************************
+ * arch/arm/src/rp2040/rp2040_cpupause.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <stdint.h>
+#include <assert.h>
+#include <debug.h>
+#include <string.h>
+#include <stdio.h>
+
+#include <nuttx/arch.h>
+#include <nuttx/spinlock.h>
+#include <nuttx/sched_note.h>
+
+#include "arm_arch.h"
+#include "sched/sched.h"
+#include "arm_internal.h"
+#include "hardware/rp2040_sio.h"
+
+#ifdef CONFIG_SMP
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#if 0
+#define DPRINTF(fmt, args...) llinfo(fmt, ##args)
+#else
+#define DPRINTF(fmt, args...) do {} while (0)
+#endif
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* These spinlocks are used in the SMP configuration in order to implement
+ * up_cpu_pause().  The protocol for CPUn to pause CPUm is as follows
+ *
+ * 1. The up_cpu_pause() implementation on CPUn locks both g_cpu_wait[m]
+ *    and g_cpu_paused[m].  CPUn then waits spinning on g_cpu_paused[m].
+ * 2. CPUm receives the interrupt it (1) unlocks g_cpu_paused[m] and
+ *    (2) locks g_cpu_wait[m].  The first unblocks CPUn and the second
+ *    blocks CPUm in the interrupt handler.
+ *
+ * When CPUm resumes, CPUn unlocks g_cpu_wait[m] and the interrupt handler
+ * on CPUm continues.  CPUm must, of course, also then unlock g_cpu_wait[m]
+ * so that it will be ready for the next pause operation.
+ */
+
+static volatile spinlock_t g_cpu_wait[CONFIG_SMP_NCPUS];
+static volatile spinlock_t g_cpu_paused[CONFIG_SMP_NCPUS];
+
+/****************************************************************************
+ * Name: rp2040_handle_irqreq
+ *
+ * Description:
+ *   If an irq handling request is found on cpu, call up_enable_irq() or
+ *   up_disable_irq().
+ *
+ * Input Parameters:
+ *   irqreq - The IRQ number to be handled (>0 : enable / <0 : disable)
+ *
+ ****************************************************************************/
+
+static void rp2040_handle_irqreq(int irqreq)

Review comment:
       If `irqreq == 0` is not an acceptable parameter, we should guard it with an assertion.
   Otherwise, `up_disable_irq` will the invoked with a `-0` argument.




----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

For queries about this service, please contact Infrastructure at:
users@infra.apache.org