stm32f7: stm32_allocateheap: allow use DTCM memory for heap

STM32F7 has up to 128KiB of DTCM memory that is currently left unused.

This patch adds DTCM to main heap if CONFIG_STM32F7_DTCMEXCLUDE is not enabled.

arch/arm/src/stm32f7/stm32_allocateheap.c

@@ -1,7 +1,7 @@
 /****************************************************************************
  * arch/arm/src/stm32f7/up_allocateheap.c
  *
- *   Copyright (C) 2015 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2015, 2017 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -57,10 +57,12 @@
 #include "up_arch.h"
 #include "up_internal.h"
 #include "stm32_mpuinit.h"
+#include "stm32_dtcm.h"
 
 /****************************************************************************
  * Pre-processor Definitions
  ****************************************************************************/
+
 /* Internal SRAM is available in all members of the STM32 family. The
  * following definitions must be provided to specify the size and
  * location of internal(system) SRAM:
@@ -92,6 +94,20 @@
 #define SRAM2_START  STM32_SRAM2_BASE
 #define SRAM2_END    (SRAM2_START + STM32F7_SRAM2_SIZE)
 
+/* The STM32 F7 has DTCM memory */
+
+#undef HAVE_DTCM
+#define HAVE_DTCM 1
+#if !defined(DTCM_START) || !defined(DTCM_END)
+#  undef HAVE_DTCM
+#endif
+
+/* DTCM to be excluded from the main heap. */
+
+#ifdef CONFIG_STM32F7_DTCMEXCLUDE
+#  undef HAVE_DTCM
+#endif
+
 /* We can't possibly have FSMC SRAM if the FSMC is not enabled */
 
 #ifndef CONFIG_STM32F7_FSMC
@@ -110,7 +126,7 @@
 #  endif
 #endif
 
-/* There are 3 possible heap configurations:
+/* There are 4 possible heap configurations:
  *
  * Configuration 1. System SRAM1 (only)
  *                  CONFIG_MM_REGIONS == 1
@@ -118,9 +134,18 @@
  * Configuration 2. System SRAM1 and SRAM2
  *                  CONFIG_MM_REGIONS == 2
  *                  CONFIG_STM32F7_FSMC_SRAM NOT defined
- * Configuration 3. System SRAM1 and SRAM2 and FSMC SRAM
+ * Configuration 3. System SRAM1 and SRAM2 and DTCM
+ *                  CONFIG_MM_REGIONS == 3
+ *                  CONFIG_STM32F7_FSMC_SRAM undefined
+ *                  HAVE_DTCM defined
+ * Configuration 4. System SRAM1 and SRAM2 and FSMC SRAM
  *                  CONFIG_MM_REGIONS == 3
  *                  CONFIG_STM32F7_FSMC_SRAM defined
+ *                  HAVE_DTCM undefined
+ * Configuration 5. System SRAM1 and SRAM2 and DTCM and FSMC SRAM
+ *                  CONFIG_MM_REGIONS == 4
+ *                  CONFIG_STM32F7_FSMC_SRAM defined
+ *                  HAVE_DTCM defined
  *
  * Let's make sure that all definitions are consistent before doing
  * anything else
@@ -128,24 +153,48 @@
 
 #if CONFIG_MM_REGIONS < 2
 #  ifdef CONFIG_STM32F7_FSMC_SRAM
-#    warning FSMC SRAM and SRAM2 excluded from the heap
+#    warning "FSMC SRAM excluded from the heap"
-#  else
+#    undef CONFIG_STM32F7_FSMC_SRAM
-#    warning "SRAM2 excluded from the heap"
 #  endif
+#  ifdef HAVE_DTCM
+#    warning "DTCM excluded from the heap"
+#    undef HAVE_DTCM
+#  endif
+#  warning "SRAM2 excluded from the heap"
 #elif CONFIG_MM_REGIONS < 3
 #  ifdef CONFIG_STM32F7_FSMC_SRAM
-#    warning FSMC SRAM excluded from the heap
+#    warning "FSMC SRAM excluded from the heap"
+#    undef CONFIG_STM32F7_FSMC_SRAM
+#  endif
+#  ifdef HAVE_DTCM
+#    warning "DTCM excluded from the heap"
+#    undef HAVE_DTCM
 #  endif
 #elif CONFIG_MM_REGIONS < 4
-#  ifndef CONFIG_STM32F7_FSMC_SRAM
+#  if defined(CONFIG_STM32F7_FSMC_SRAM) && defined(HAVE_DTCM)
-#    error  CONFIG_MM_REGIONS > 2 but I do not know what some of the region(s) are
+#    warning "CONFIG_MM_REGIONS == 3 but have both FSMC SRAM and DTCM. DTCM excluded from the heap."
+#    undef  HAVE_DTCM
+#  elif !defined(CONFIG_STM32F7_FSMC_SRAM) && !defined(HAVE_DTCM)
+#    error  "CONFIG_MM_REGIONS == 3 but I do not know what some of the region(s) are"
 #    undef  CONFIG_MM_REGIONS
 #    define CONFIG_MM_REGIONS 2
 #  endif
+#elif CONFIG_MM_REGIONS < 5
+#  if !defined(CONFIG_STM32F7_FSMC_SRAM) && !defined(HAVE_DTCM)
+#    error  "CONFIG_MM_REGIONS == 4 but I do not know what some of the region(s) are"
+#    undef  CONFIG_MM_REGIONS
+#    define CONFIG_MM_REGIONS 2
+#  elif !defined(CONFIG_STM32F7_FSMC_SRAM) || !defined(HAVE_DTCM)
+#    error  "CONFIG_MM_REGIONS == 4 but I do not know what some of the region(s) are"
+#    undef  CONFIG_MM_REGIONS
+#    define CONFIG_MM_REGIONS 3
+#  endif
 #else
-#  error CONFIG_MM_REGIONS > 3 but I do not know what some of the region(s) are
+#  error "CONFIG_MM_REGIONS > 4 but I do not know what some of the region(s) are"
 #  undef CONFIG_MM_REGIONS
-#  ifdef CONFIG_STM32F7_FSMC_SRAM
+#  if defined(CONFIG_STM32F7_FSMC_SRAM) && defined(HAVE_DTCM)
+#    define CONFIG_MM_REGIONS 4
+#  elif defined(CONFIG_STM32F7_FSMC_SRAM) || defined(HAVE_DTCM)
 #    define CONFIG_MM_REGIONS 3
 #  else
 #    define CONFIG_MM_REGIONS 2
@@ -338,6 +387,24 @@ void up_addregion(void)
 
   kumm_addregion((FAR void *)SRAM2_START, SRAM2_END-SRAM2_START);
 
+#ifdef HAVE_DTCM
+#if defined(CONFIG_BUILD_PROTECTED) && defined(CONFIG_MM_KERNEL_HEAP)
+
+  /* Allow user-mode access to the DTCM heap */
+
+  stm32_mpu_uheap((uintptr_t)DTCM_START, DTCM_END-DTCM_START);
+
+#endif
+
+  /* Colorize the heap for debug */
+
+  up_heap_color((FAR void *)DTCM_START, DTCM_END-DTCM_START);
+
+  /* Add the DTCM user heap region. */
+
+  kumm_addregion((FAR void *)DTCM_START, DTCM_END-DTCM_START);
+#endif
+
 #ifdef CONFIG_STM32F7_FSMC_SRAM
 #if defined(CONFIG_BUILD_PROTECTED) && defined(CONFIG_MM_KERNEL_HEAP)
 

configs/nucleo-144/f767-evalos/defconfig

@@ -747,7 +747,7 @@ CONFIG_FS_MQUEUE_MPATH="/var/mqueue"
 # Memory Management
 #
 # CONFIG_MM_SMALL is not set
-CONFIG_MM_REGIONS=2
+CONFIG_MM_REGIONS=3
 # CONFIG_ARCH_HAVE_HEAP2 is not set
 # CONFIG_GRAN is not set
 

configs/nucleo-144/f767-nsh/defconfig

@@ -734,7 +734,7 @@ CONFIG_FS_MQUEUE_MPATH="/var/mqueue"
 # Memory Management
 #
 # CONFIG_MM_SMALL is not set
-CONFIG_MM_REGIONS=2
+CONFIG_MM_REGIONS=3
 # CONFIG_ARCH_HAVE_HEAP2 is not set
 # CONFIG_GRAN is not set
 

configs/stm32f746-ws/nsh/defconfig

@@ -862,7 +862,7 @@ CONFIG_FAT_DIRECT_RETRY=y
 # Memory Management
 #
 # CONFIG_MM_SMALL is not set
-CONFIG_MM_REGIONS=2
+CONFIG_MM_REGIONS=3
 # CONFIG_ARCH_HAVE_HEAP2 is not set
 CONFIG_GRAN=y
 # CONFIG_GRAN_SINGLE is not set

configs/stm32f746g-disco/nsh/defconfig

@@ -732,7 +732,7 @@ CONFIG_FS_MQUEUE_MPATH="/var/mqueue"
 # Memory Management
 #
 # CONFIG_MM_SMALL is not set
-CONFIG_MM_REGIONS=2
+CONFIG_MM_REGIONS=3
 # CONFIG_ARCH_HAVE_HEAP2 is not set
 # CONFIG_GRAN is not set