SAMV7 QSPI: When QSPI is enabled, make the QSPI memory strongly ordered

arch/arm/src/armv7-m/cache.h

@@ -76,9 +76,11 @@
 
 #define arm_isb(n) __asm__ __volatile__ ("isb " #n : : : "memory")
 #define arm_dsb(n) __asm__ __volatile__ ("dsb " #n : : : "memory")
+#define arm_dmb(n) __asm__ __volatile__ ("dmb " #n : : : "memory")
 
 #define ARM_DSB()  arm_dsb(15)
 #define ARM_ISB()  arm_isb(15)
+#define ARM_DMB()  arm_dmb(15)
 
 /****************************************************************************
  * Inline Functions

arch/arm/src/samv7/chip/samv71_memorymap.h

@@ -159,6 +159,10 @@
 #  define SAM_EXTCS3_BASE      0x63000000 /* 0x63000000-0x6fffffff:   EBI Chip select 3 */
 #define SAM_SDRAMCS_BASE       0x70000000 /* 0x70000000-0x7fffffff: SDRAM chip select */
 
+/* QSPI memory region */
+
+#define SAM_QSPIMEM_SIZE       0x20000000 /* 0x80000000-0x9fffffff: QSPI memory */
+
 /* System memory region */
 
 #define SAM_PRIVPERIPH_BASE    0xe0000000 /* 0xe0000000-0xe00fffff: Private peripheral bus */

arch/arm/src/samv7/sam_mpuinit.c

@@ -44,6 +44,9 @@
 #include <nuttx/userspace.h>
 
 #include "mpu.h"
+#include "cache.h"
+#include "chip/sam_memorymap.h"
+
 #include "sam_mpuinit.h"
 
 #ifdef CONFIG_ARMV7M_MPU
@@ -84,23 +87,40 @@
 void sam_mpu_initialize(void)
 {
 #ifdef CONFIG_BUILD_PROTECTED
-  uintptr_t datastart = MIN(USERSPACE->us_datastart, USERSPACE->us_bssstart);
-  uintptr_t dataend   = MAX(USERSPACE->us_dataend,   USERSPACE->us_bssend);
-
-  DEBUGASSERT(USERSPACE->us_textend >= USERSPACE->us_textstart &&
-              dataend >= datastart);
+  uintptr_t datastart;
+  uintptr_t dataend;
 #endif
 
   /* Show MPU information */
 
   mpu_showtype();
 
+#ifdef CONFIG_ARMV7M_DCACHE
+  /* Memory barrier */
+
+  ARM_DMB();
+
+#ifdef CONFIG_SAMV7_QSPI
+  /* Make QSPI memory region strongly ordered */
+
+  mpu_priv_stronglyordered(SAM_QSPIMEM_BASE, SAM_QSPIMEM_SIZE);
+
+#endif
+#endif
+
 #ifdef CONFIG_BUILD_PROTECTED
   /* Configure user flash and SRAM space */
 
+  DEBUGASSERT(USERSPACE->us_textend >= USERSPACE->us_textstart);
+
   mpu_user_flash(USERSPACE->us_textstart,
                  USERSPACE->us_textend - USERSPACE->us_textstart);
 
+  datastart = MIN(USERSPACE->us_datastart, USERSPACE->us_bssstart);
+  dataend   = MAX(USERSPACE->us_dataend,   USERSPACE->us_bssend);
+
+  DEBUGASSERT(dataend >= datastart);
+
   mpu_user_intsram(datastart, dataend - datastart);
 #endif
 

arch/arm/src/samv7/sam_start.c

@@ -55,6 +55,7 @@
 #endif
 
 #include "sam_clockconfig.h"
+#include "sam_mpuinit.h"
 #include "sam_userspace.h"
 #include "sam_start.h"