/*
* (c) 1999, Eric Valette valette@crf.canon.fr
*
* Modified and partially rewritten by Till Straumann, 2007
*
* Modified by Sebastian Huber <sebastian.huber@embedded-brains.de>, 2008.
*
* Low-level assembly code for PPC exceptions.
*
* This file was written with the goal to eliminate
* ALL #ifdef <cpu_flavor> conditionals -- please do not
* reintroduce such statements.
*/
/* Load macro definitions */
#include <rtems/asm.h>
#include <rtems/system.h>
#include <rtems/score/percpu.h>
#include "ppc_exc_asm_macros.h"
/******************************************************/
/* PROLOGUES */
/******************************************************/
/*
* Expand prologue snippets for classic, ppc405-critical, bookE-critical
* and E500 machine-check, synchronous and asynchronous exceptions
*/
PPC_EXC_MIN_PROLOG_SYNC _NAME=tmpl_std _VEC=0 _PRI=std _FLVR=std
PPC_EXC_MIN_PROLOG_SYNC _NAME=tmpl_p405_crit _VEC=0 _PRI=crit _FLVR=p405_crit
PPC_EXC_MIN_PROLOG_SYNC _NAME=tmpl_bookE_crit _VEC=0 _PRI=crit _FLVR=bookE_crit
PPC_EXC_MIN_PROLOG_SYNC _NAME=tmpl_e500_mchk _VEC=0 _PRI=mchk _FLVR=e500_mchk
PPC_EXC_MIN_PROLOG_ASYNC _NAME=tmpl_std _VEC=0 _PRI=std _FLVR=std
PPC_EXC_MIN_PROLOG_ASYNC _NAME=tmpl_p405_crit _VEC=0 _PRI=crit _FLVR=p405_crit
PPC_EXC_MIN_PROLOG_ASYNC _NAME=tmpl_bookE_crit _VEC=0 _PRI=crit _FLVR=bookE_crit
PPC_EXC_MIN_PROLOG_ASYNC _NAME=tmpl_e500_mchk _VEC=0 _PRI=mchk _FLVR=e500_mchk
.global ppc_exc_min_prolog_size
ppc_exc_min_prolog_size = 4 * 4
/* Special prologue for 603e-style CPUs.
*
* 603e shadows GPR0..GPR3 for certain exceptions. We must switch
* that off before we can use the stack pointer. Note that this is
* ONLY safe if the shadowing is actually active -- otherwise, r1
* is destroyed. We deliberately use r1 so problems become obvious
* if this is misused!
*/
.global ppc_exc_tgpr_clr_prolog
ppc_exc_tgpr_clr_prolog:
mfmsr r1
rlwinm r1,r1,0,15,13
mtmsr r1
isync
/* FALL THRU TO 'auto' PROLOG */
/* Determine vector dynamically/automatically
*
* BUT: - only standard exceptions (no critical ones)
* - vector offset must be on 256 Byte boundary.
*/
.global ppc_exc_min_prolog_auto
ppc_exc_min_prolog_auto:
stwu r1, -EXCEPTION_FRAME_END(r1)
stw VECTOR_REGISTER, VECTOR_OFFSET(r1)
mflr VECTOR_REGISTER
/*
* We store the absolute branch target address here. It will be used
* to generate the branch operation in ppc_exc_make_prologue().
*
* We add one to request the link in the generated branch instruction.
*/
.int ppc_exc_wrap_auto + 1
.global ppc_exc_tgpr_clr_prolog_size
ppc_exc_tgpr_clr_prolog_size = . - ppc_exc_tgpr_clr_prolog
/*
* Automatic vector, asynchronous exception; however,
* automatic vector calculation is less efficient than
* using an explicit vector in a minimal prolog snippet.
* The latter method is preferable since there usually
* are few asynchronous exceptions.
*
* For generic exceptions (which are the bulk) using
* the 'auto' prologue is OK since performance is not
* really an issue.
*/
.global ppc_exc_min_prolog_auto_async
ppc_exc_min_prolog_auto_async:
stw r1, ppc_exc_lock_std@sdarel(r13)
stw VECTOR_REGISTER, ppc_exc_vector_register_std@sdarel(r13)
mflr VECTOR_REGISTER
/*
* We store the absolute branch target address here. It will be used
* to generate the branch operation in ppc_exc_make_prologue().
*
* We add one to request the link in the generated branch instruction.
*/
.int ppc_exc_wrap_auto_async + 1
/******************************************************/
/* WRAPPERS */
/******************************************************/
/* Tag start and end of the wrappers.
* If exceptions are installed farther removed
* from the text area than 32M then the wrappers
* must be moved to an area that is reachable
* from where the prologues reside. Branches into
* C-code are far.
*/
.global __ppc_exc_wrappers_start
__ppc_exc_wrappers_start = .
/* Expand wrappers for different exception flavors */
/* Standard/classic powerpc */
WRAP _FLVR=std _PRI=std _SRR0=srr0 _SRR1=srr1 _RFI=rfi
/* ppc405 has a critical exception using srr2/srr3 */
WRAP _FLVR=p405_crit _PRI=crit _SRR0=srr2 _SRR1=srr3 _RFI=rfci
/* bookE has critical exception using csrr0 cssr1 */
WRAP _FLVR=bookE_crit _PRI=crit _SRR0=csrr0 _SRR1=csrr1 _RFI=rfci
/* e500 has machine-check exception using mcsrr0 mcssr1 */
WRAP _FLVR=e500_mchk _PRI=mchk _SRR0=mcsrr0 _SRR1=mcsrr1 _RFI=rfmci
/* LR holds vector, VECTOR_REGISTER holds orig. LR */
.global ppc_exc_wrap_auto
ppc_exc_wrap_auto:
stw FRAME_REGISTER, FRAME_OFFSET(r1)
/* Find address where we jumped from */
mflr FRAME_REGISTER
/* Restore LR */
mtlr VECTOR_REGISTER
/* Compute vector into R3 */
rlwinm VECTOR_REGISTER, FRAME_REGISTER, 24, 26, 31
/*
* We're now in almost the same state as if called by
* min_prolog_std but we must skip saving FRAME_REGISTER
* since that's done already
*/
b wrap_no_save_frame_register_std
.global ppc_exc_wrap_auto_async
ppc_exc_wrap_auto_async:
stwu r1, -EXCEPTION_FRAME_END(r1)
stw FRAME_REGISTER, FRAME_OFFSET(r1)
/* find address where we jumped from */
mflr FRAME_REGISTER
/* restore LR */
mtlr VECTOR_REGISTER
/* set upper bits to indicate that non-volatile
* registers should not be saved/restored.
*/
li VECTOR_REGISTER, 0xffff8000
/* compute vector into R3 */
rlwimi VECTOR_REGISTER, FRAME_REGISTER, 24, 26, 31
/* we're now in almost the same state as if called by
* min_prolog_std but we must skip saving FRAME_REGISTER
* since that's done already
*/
b wrap_no_save_frame_register_std
.global __ppc_exc_wrappers_end
__ppc_exc_wrappers_end = .
