bsps/powerpc: Add PPC_EXC_CONFIG_USE_FIXED_HANDLER

In case a BSP enables this option, then fixed high level exception
handler will be used.  For normal asynchronous exceptions this is
bsp_interrupt_dispatch() and for other exceptions this is the handler
from the read-only ppc_exc_handler_table.  The global handler is
C_exception_handler().  This avoids some dependencies on valid
read-write data.

1 files changed, 39 insertions, 16 deletions

diff --git a/c/src/lib/libcpu/powerpc/new-exceptions/bspsupport/vectors.h b/c/src/lib/libcpu/powerpc/new-exceptions/bspsupport/vectors.h
index 2f1ec37290..bcb3b9a114 100644
--- a/c/src/lib/libcpu/powerpc/new-exceptions/bspsupport/vectors.h
+++ b/c/src/lib/libcpu/powerpc/new-exceptions/bspsupport/vectors.h
@@ -35,6 +35,8 @@
 #ifndef LIBCPU_VECTORS_H
 #define LIBCPU_VECTORS_H
 
+#include <bspopts.h>
+
 #include <libcpu/powerpc-utility.h>
 
 #ifdef __cplusplus
@@ -262,11 +264,6 @@ typedef CPU_Exception_frame BSP_Exception_frame;
 typedef void (*exception_handler_t)(BSP_Exception_frame*);
 
 /**
- * @brief Global exception handler.
- */
-extern exception_handler_t globalExceptHdl;
-
-/**
  * @brief Default global exception handler.
  */
 void C_exception_handler(BSP_Exception_frame* excPtr);
@@ -399,17 +396,21 @@ void ppc_exc_initialize(
 /**
  * @brief High-level exception handler type.
  *
- * Exception handlers should return zero if the exception was handled and
- * normal execution may resume.
- *
- * They should return minus one to reject the exception resulting in the
- * globalExcHdl() being called.
- *
- * Other return values are reserved.
+ * @retval 0 The exception was handled and normal execution may resume.
+ * @retval -1 Reject the exception resulting in a call of the global exception
+ * handler.
+ * @retval other Reserved, do not use.
  */
 typedef int (*ppc_exc_handler_t)(BSP_Exception_frame *f, unsigned vector);
 
 /**
+ * @brief Default high-level exception handler.
+ *
+ * @retval -1 Always.
+ */
+int ppc_exc_handler_default(BSP_Exception_frame *f, unsigned int vector);
+
+/**
  * @brief Bits for MSR update.
  *
  * Bits in MSR that are enabled during execution of exception handlers / ISRs
@@ -436,10 +437,27 @@ extern uint32_t ppc_exc_msr_bits;
  */
 extern uint32_t ppc_exc_cache_wb_check;
 
-/**
- * @brief High-level exception handler table.
- */
-extern ppc_exc_handler_t ppc_exc_handler_table [LAST_VALID_EXC + 1];
+#ifndef PPC_EXC_CONFIG_USE_FIXED_HANDLER
+  /**
+   * @brief High-level exception handler table.
+   */
+  extern ppc_exc_handler_t ppc_exc_handler_table [LAST_VALID_EXC + 1];
+
+  /**
+   * @brief Global exception handler.
+   */
+  extern exception_handler_t globalExceptHdl;
+#else /* PPC_EXC_CONFIG_USE_FIXED_HANDLER */
+  /**
+   * @brief High-level exception handler table.
+   */
+  extern const ppc_exc_handler_t ppc_exc_handler_table [LAST_VALID_EXC + 1];
+
+  /**
+   * @brief Interrupt dispatch routine provided by BSP.
+   */
+  void bsp_interrupt_dispatch(void);
+#endif /* PPC_EXC_CONFIG_USE_FIXED_HANDLER */
 
 /**
  * @brief Set high-level exception handler.
@@ -457,6 +475,11 @@ extern ppc_exc_handler_t ppc_exc_handler_table [LAST_VALID_EXC + 1];
  *
  * It is legal to set a NULL handler. This leads to the globalExcHdl
  * being called if an exception for 'vector' occurs.
+ *
+ * @retval RTEMS_SUCCESSFUL Successful operation.
+ * @retval RTEMS_INVALID_ID Invalid vector number.
+ * @retval RTEMS_RESOURCE_IN_USE Handler table is read-only and handler does
+ * not match.
  */
 rtems_status_code ppc_exc_set_handler(unsigned vector, ppc_exc_handler_t hdl);