From 0169a51220a68d8d3bed0c20b6d606f43497a9e9 Mon Sep 17 00:00:00 2001
From: ligd <liguiding1@xiaomi.com>
Date: Mon, 14 Feb 2022 16:47:42 +0800
Subject: [PATCH] mm: handle take mm sem in IRQ

Signed-off-by: ligd <liguiding1@xiaomi.com>
---
 mm/mm_heap/mm_foreach.c |  5 ++++-
 mm/mm_heap/mm_sem.c     | 25 +++++++++++++++++++++++--
 2 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/mm/mm_heap/mm_foreach.c b/mm/mm_heap/mm_foreach.c
index 25cec561f1..f2ad78bc26 100644
--- a/mm/mm_heap/mm_foreach.c
+++ b/mm/mm_heap/mm_foreach.c
@@ -68,7 +68,10 @@ void mm_foreach(FAR struct mm_heap_s *heap, mmchunk_handler_t handler,
        * Retake the semaphore for each region to reduce latencies
        */
 
-      DEBUGVERIFY(mm_takesemaphore(heap));
+      if (!mm_takesemaphore(heap))
+        {
+          return;
+        }
 
       for (node = heap->mm_heapstart[region];
            node < heap->mm_heapend[region];
diff --git a/mm/mm_heap/mm_sem.c b/mm/mm_heap/mm_sem.c
index a4d4e869c7..b26a0dec97 100644
--- a/mm/mm_heap/mm_sem.c
+++ b/mm/mm_heap/mm_sem.c
@@ -104,9 +104,23 @@ bool mm_takesemaphore(FAR struct mm_heap_s *heap)
 #if defined(CONFIG_BUILD_FLAT) || defined(__KERNEL__)
   else if (sched_idletask())
     {
-      /* Try to take the semaphore */
+      return false;
+    }
+  else if (up_interrupt_context())
+    {
+#ifdef CONFIG_SMP
+      return false;
+#else
+      int val;
 
-      return _SEM_TRYWAIT(&heap->mm_semaphore) >= 0;
+      /* Check the semaphore value, if held by someone, then return false.
+       * Else, we can take it, return true.
+       */
+
+      _SEM_GETVALUE(&heap->mm_semaphore, &val);
+
+      return val > 0;
+#endif
     }
 #endif
   else
@@ -145,5 +159,12 @@ bool mm_takesemaphore(FAR struct mm_heap_s *heap)
 
 void mm_givesemaphore(FAR struct mm_heap_s *heap)
 {
+#if defined(CONFIG_BUILD_FLAT) || defined(__KERNEL__)
+  if (up_interrupt_context())
+    {
+      return;
+    }
+#endif
+
   DEBUGVERIFY(_SEM_POST(&heap->mm_semaphore));
 }