forked from Imagelibrary/rtems
a51b3526ea
The SPARC ABI is a bit special with respect to the floating point context. The complete floating point context is volatile. Thus from an ABI point of view nothing needs to be saved and restored during a context switch. Instead the floating point context must be saved and restored during interrupt processing. Historically the deferred floating point switch is used for SPARC and the complete floating point context is saved and restored during a context switch to the new floating point unit owner. This is a bit dangerous since post-switch actions (e.g. signal handlers) and context switch extensions may silently corrupt the floating point context. The floating point unit is disabled for interrupt handlers. Thus in case an interrupt handler uses the floating point unit then this will result in a trap. On SMP configurations the deferred floating point switch is not supported in principle. So use here a safe floating point support. Safe means that the volatile floating point context is saved and restored around a thread dispatch issued during interrupt processing. Thus post-switch actions and context switch extensions may safely use the floating point unit. Update #2270.
106 lines
3.4 KiB
ArmAsm
106 lines
3.4 KiB
ArmAsm
/* cpu_asm.s
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*
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* This file contains the basic algorithms for all assembly code used
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* in an specific CPU port of RTEMS. These algorithms must be implemented
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* in assembly language.
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*
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* COPYRIGHT (c) 1989-2011.
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* On-Line Applications Research Corporation (OAR).
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*
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* The license and distribution terms for this file may be
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* found in the file LICENSE in this distribution or at
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* http://www.rtems.org/license/LICENSE.
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*
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* Ported to ERC32 implementation of the SPARC by On-Line Applications
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* Research Corporation (OAR) under contract to the European Space
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* Agency (ESA).
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*
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* ERC32 modifications of respective RTEMS file: COPYRIGHT (c) 1995.
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* European Space Agency.
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*/
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#ifdef HAVE_CONFIG_H
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#include "config.h"
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#endif
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#include <rtems/asm.h>
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#include <rtems/system.h>
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#if (SPARC_HAS_FPU == 1) && !defined(SPARC_USE_SAFE_FP_SUPPORT)
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/*
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* void _CPU_Context_save_fp(
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* void **fp_context_ptr
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* )
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*
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* This routine is responsible for saving the FP context
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* at *fp_context_ptr. If the point to load the FP context
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* from is changed then the pointer is modified by this routine.
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*
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* NOTE: See the README in this directory for information on the
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* management of the "EF" bit in the PSR.
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*/
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.align 4
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PUBLIC(_CPU_Context_save_fp)
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SYM(_CPU_Context_save_fp):
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ld [%o0], %o1
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std %f0, [%o1 + FO_F1_OFFSET]
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std %f2, [%o1 + F2_F3_OFFSET]
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std %f4, [%o1 + F4_F5_OFFSET]
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std %f6, [%o1 + F6_F7_OFFSET]
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std %f8, [%o1 + F8_F9_OFFSET]
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std %f10, [%o1 + F1O_F11_OFFSET]
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std %f12, [%o1 + F12_F13_OFFSET]
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std %f14, [%o1 + F14_F15_OFFSET]
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std %f16, [%o1 + F16_F17_OFFSET]
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std %f18, [%o1 + F18_F19_OFFSET]
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std %f20, [%o1 + F2O_F21_OFFSET]
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std %f22, [%o1 + F22_F23_OFFSET]
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std %f24, [%o1 + F24_F25_OFFSET]
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std %f26, [%o1 + F26_F27_OFFSET]
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std %f28, [%o1 + F28_F29_OFFSET]
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std %f30, [%o1 + F3O_F31_OFFSET]
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jmp %o7 + 8
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st %fsr, [%o1 + FSR_OFFSET]
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/*
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* void _CPU_Context_restore_fp(
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* void **fp_context_ptr
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* )
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*
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* This routine is responsible for restoring the FP context
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* at *fp_context_ptr. If the point to load the FP context
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* from is changed then the pointer is modified by this routine.
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*
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* NOTE: See the README in this directory for information on the
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* management of the "EF" bit in the PSR.
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*/
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.align 4
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PUBLIC(_CPU_Context_restore_fp)
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SYM(_CPU_Context_restore_fp):
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ld [%o0], %o1
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ldd [%o1 + FO_F1_OFFSET], %f0
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ldd [%o1 + F2_F3_OFFSET], %f2
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ldd [%o1 + F4_F5_OFFSET], %f4
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ldd [%o1 + F6_F7_OFFSET], %f6
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ldd [%o1 + F8_F9_OFFSET], %f8
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ldd [%o1 + F1O_F11_OFFSET], %f10
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ldd [%o1 + F12_F13_OFFSET], %f12
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ldd [%o1 + F14_F15_OFFSET], %f14
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ldd [%o1 + F16_F17_OFFSET], %f16
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ldd [%o1 + F18_F19_OFFSET], %f18
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ldd [%o1 + F2O_F21_OFFSET], %f20
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ldd [%o1 + F22_F23_OFFSET], %f22
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ldd [%o1 + F24_F25_OFFSET], %f24
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ldd [%o1 + F26_F27_OFFSET], %f26
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ldd [%o1 + F28_F29_OFFSET], %f28
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ldd [%o1 + F3O_F31_OFFSET], %f30
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jmp %o7 + 8
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ld [%o1 + FSR_OFFSET], %fsr
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#endif /* SPARC_HAS_FPU */
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/* end of file */
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