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/* PowerPC exception handling middleware; consult README for more
* information.
*
* Author: Till Straumann <strauman@slac.stanford.edu>, 2007
*
* The license and distribution terms for this file may be
* found in found in the file LICENSE in this distribution or at
* http://www.rtems.com/license/LICENSE.
*
* $Id$
*/
#ifndef PPC_EXC_SHARED_H
#define PPC_EXC_SHARED_H
#include <stdint.h>
#include "vectors.h"
#ifdef __cplusplus
extern "C" {
#endif
/********* C-Exception Handlers *********************/
/* API to be used by middleware, */
/* BSP and application code (if necessary) */
/****************************************************/
/*
* Exception handlers should return 0 if the exception
* was handled and normal execution may resume.
*
* They should return (-1) to 'rethrow' the exception
* resulting in the globalExcHdl() being called.
*
* Other return values are reserved.
*/
typedef int (*ppc_exc_handler_t)(BSP_Exception_frame *f, unsigned int vector);
/*
* Bits in MSR that are enabled during execution of exception handlers / ISRs
* (on classic PPC these are DR/IR/RI [default], on bookE-style CPUs they should
* be set to 0 during initialization)
*
* By default, the setting of these bits that is in effect when exception
* handling is initialized is used.
*/
extern uint32_t ppc_exc_msr_bits;
/* (See README under CAVEATS). During initialization
* a check is performed to assert that write-back
* caching is enabled for memory accesses. If a BSP
* runs entirely without any caching then it should
* set this variable to zero prior to initializing
* exceptions in order to skip the test.
* NOTE: The code does NOT support mapping memory
* with cache-attributes other than write-back
* (unless the entire cache is physically disabled)
*/
extern uint32_t ppc_exc_cache_wb_check;
/*
* Hook C exception handlers.
* - handlers for asynchronous exceptions run on the ISR stack
* with thread-dispatching disabled.
* - handlers for synchronous exceptions run on the task stack
* with thread-dispatching enabled.
*
* If a particular slot is NULL then the traditional 'globalExcHdl' is used.
*
* ppc_exc_set_handler() registers a handler (returning 0 on success,
* -1 if the vector argument is too big).
*
* It is legal to set a NULL handler. This leads to the globalExcHdl
* being called if an exception for 'vector' occurs.
*/
int
ppc_exc_set_handler(unsigned vector, ppc_exc_handler_t hdl);
/* ppc_exc_get_handler() retrieves the currently active handler.
*/
ppc_exc_handler_t
ppc_exc_get_handler(unsigned vector);
/********* Low-level Exception Handlers *************/
/* This part of the API is used by middleware code */
/****************************************************/
typedef uint32_t ppc_exc_min_prolog_t[4];
/* Templates are ppc_raw_except_func BUT they must be exactly 16 bytes */
typedef rtems_raw_except_func ppc_exc_min_prolog_template_t;
/*
* Expand a prolog template into 'buf' using vector 'vec'
*/
void
ppc_exc_min_prolog_expand(ppc_exc_min_prolog_t buf, ppc_exc_min_prolog_template_t templ, uint16_t vec);
extern unsigned ppc_exc_min_prolog_size[];
/* Symbols are defined by the linker; declare as an array so
* that gcc doesn't attempt to emit a relocation looking for
* it in the SDA section
*/
extern unsigned ppc_exc_tgpr_clr_prolog_size[];
/* Templates for ppc_exc_min_prolog_expand() which fills-in the vector information */
extern void ppc_exc_min_prolog_async_tmpl_std(void);
extern void ppc_exc_min_prolog_sync_tmpl_std(void);
extern void ppc_exc_min_prolog_async_tmpl_p405_crit(void);
extern void ppc_exc_min_prolog_sync_tmpl_p405_crit(void);
extern void ppc_exc_min_prolog_async_tmpl_bookE_crit(void);
extern void ppc_exc_min_prolog_sync_tmpl_bookE_crit(void);
extern void ppc_exc_min_prolog_sync_tmpl_e500_mchk(void);
extern void ppc_exc_min_prolog_async_tmpl_e500_mchk(void);
extern void ppc_exc_min_prolog_tmpl_naked(void);
/* Special prologue for handling register shadowing on 603-style CPUs */
extern void ppc_exc_tgpr_clr_prolog(void);
/* Classic prologue which determines the vector dynamically from
* the offset address. This must only be used for classic, synchronous
* exceptions with a vector offset aligned on a 256-byte boundary.
*/
extern void ppc_exc_min_prolog_auto(void);
extern void ppc_exc_min_prolog_auto_packed(void);
/* CPU support may store the address of a function here
* that can be used by the default exception handler to
* obtain fault-address info which is helpful. Unfortunately,
* the SPR holding this information is not uniform
* across PPC families so we need assistance from
* CPU support
*/
extern uint32_t (*ppc_exc_get_DAR)(void);
#ifdef __cplusplus
};
#endif
#endif
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