arch/risc-v/qemu-rv: Configure PMP before booting secondary harts.

Export qemu_rv_configure_mpu() and invoke it on the secondary-hart
boot path before riscv_cpu_boot().

This keeps protected SMP builds from faulting on !CPU0 when userspace
work is first scheduled there.

Signed-off-by: Shunchao Hu <ankohuu@gmail.com>

arch/risc-v/src/qemu-rv/qemu_rv_start.c

@@ -227,6 +227,9 @@ void qemu_rv_start(int mhartid, const char *dtb)
 cpux:
 
 #ifdef CONFIG_SMP
+#  ifdef CONFIG_BUILD_PROTECTED
+  qemu_rv_configure_mpu();
+#  endif
   riscv_cpu_boot(mhartid);
 #endif
 

arch/risc-v/src/qemu-rv/qemu_rv_userspace.c

@@ -55,7 +55,7 @@
  ****************************************************************************/
 
 /****************************************************************************
- * Name: configure_mpu
+ * Name: qemu_rv_configure_mpu
  *
  * Description:
  *   This function configures the MPU for for kernel- / userspace separation.
@@ -63,7 +63,7 @@
  *
  ****************************************************************************/
 
-static void configure_mpu(void)
+void qemu_rv_configure_mpu(void)
 {
   int ret;
   ret = riscv_append_pmp_region(UFLASH_F, UFLASH_START, UFLASH_SIZE);
@@ -123,7 +123,7 @@ void qemu_rv_userspace(void)
 
   /* Configure MPU / PMP to grant access to the userspace */
 
-  configure_mpu();
+  qemu_rv_configure_mpu();
 }
 
 #endif /* CONFIG_BUILD_PROTECTED */

arch/risc-v/src/qemu-rv/qemu_rv_userspace.h

@@ -45,6 +45,7 @@
  ****************************************************************************/
 
 #ifdef CONFIG_BUILD_PROTECTED
+void qemu_rv_configure_mpu(void);
 void qemu_rv_userspace(void);
 #endif