target/xtensa: use MPU background map from core configuration

Configuration overlay may define MPU background map. Import
core-matmap.h from the overlay and use XCHAL_MPU_BACKGROUND_MAP macro
if it's defined.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

target/xtensa/import_core.sh

@@ -20,7 +20,8 @@ exit
 [ $# -ge 3 ] && FREQ="$3"
 mkdir -p "$TARGET"
 tar -xf "$OVERLAY" -C "$TARGET" --strip-components=2 \
-    xtensa/config/core-isa.h
+    xtensa/config/core-isa.h \
+    xtensa/config/core-matmap.h
 tar -xf "$OVERLAY" -O gdb/xtensa-config.c | \
     sed -n '1,/*\//p;/XTREG/,/XTREG_END/p' > "$TARGET"/gdb-config.inc.c
 #
@@ -44,6 +45,7 @@ cat <<EOF > "${TARGET}.c"
 #include "qemu/host-utils.h"
 
 #include "core-$NAME/core-isa.h"
+#include "core-$NAME/core-matmap.h"
 #include "overlay_tool.h"
 
 #define xtensa_modules xtensa_modules_$NAME

target/xtensa/overlay_tool.h

@@ -373,15 +373,28 @@
 #elif XCHAL_HAVE_MPU
 
 #ifndef XTENSA_MPU_BG_MAP
+#ifdef XCHAL_MPU_BACKGROUND_MAP
+#define XCHAL_MPU_BGMAP(s, vaddr_start, vaddr_last, rights, memtype, x...) \
+    { .vaddr = (vaddr_start), .attr = ((rights) << 8) | ((memtype) << 12), },
+
+#define XTENSA_MPU_BG_MAP (xtensa_mpu_entry []){\
+    XCHAL_MPU_BACKGROUND_MAP(0) \
+}
+
+#define XTENSA_MPU_BG_MAP_ENTRIES XCHAL_MPU_BACKGROUND_ENTRIES
+#else
 #define XTENSA_MPU_BG_MAP (xtensa_mpu_entry []){\
     { .vaddr = 0, .attr = 0x00006700, }, \
 }
+
+#define XTENSA_MPU_BG_MAP_ENTRIES 1
+#endif
 #endif
 
 #define TLB_SECTION \
     .mpu_align = XCHAL_MPU_ALIGN, \
     .n_mpu_fg_segments = XCHAL_MPU_ENTRIES, \
-    .n_mpu_bg_segments = 1, \
+    .n_mpu_bg_segments = XTENSA_MPU_BG_MAP_ENTRIES, \
     .mpu_bg = XTENSA_MPU_BG_MAP
 
 #ifndef XCHAL_SYSROM0_PADDR