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/* |
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* Copyright (C) 2005-2008 by Pieter Palmers |
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* |
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* This file is part of FFADO |
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* FFADO = Free Firewire (pro-)audio drivers for linux |
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* |
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* FFADO is based upon FreeBoB. |
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* |
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* This program is free software: you can redistribute it and/or modify |
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* it under the terms of the GNU General Public License as published by |
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* the Free Software Foundation, either version 2 of the License, or |
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* (at your option) version 3 of the License. |
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* |
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* This program is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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* GNU General Public License for more details. |
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* |
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* You should have received a copy of the GNU General Public License |
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* along with this program. If not, see <http://www.gnu.org/licenses/>. |
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* |
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*/ |
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/* cycles.h |
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* Based upon cycles.h from the jackdmp package. |
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* Original Copyright: |
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* |
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* Copyright (C) 2001 Paul Davis |
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* Code derived from various headers from the Linux kernel |
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* |
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* This program is free software; you can redistribute it and/or modify |
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* it under the terms of the GNU General Public License as published by |
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* the Free Software Foundation; either version 2 of the License, or |
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* (at your option) version 3 of the License. |
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* |
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* This program is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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* GNU General Public License for more details. |
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* |
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* You should have received a copy of the GNU General Public License |
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* along with this program; if not, write to the Free Software |
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
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* |
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*/ |
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#ifndef __FFADO_CYCLES_H__ |
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#define __FFADO_CYCLES_H__ |
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/* |
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* Standard way to access the cycle timer on i586+ CPUs. |
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* Currently only used on SMP. |
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* |
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* If you really have a SMP machine with i486 chips or older, |
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* compile for that, and this will just always return zero. |
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* That's ok, it just means that the nicer scheduling heuristics |
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* won't work for you. |
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* |
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* We only use the low 32 bits, and we'd simply better make sure |
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* that we reschedule before that wraps. Scheduling at least every |
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* four billion cycles just basically sounds like a good idea, |
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* regardless of how fast the machine is. |
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*/ |
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#ifdef __linux__ |
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#ifdef __PPC__ |
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/* PowerPC */ |
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#define CPU_FTR_601 0x00000100 |
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typedef unsigned long cycles_t; |
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/* For the "cycle" counter we use the timebase lower half. */ |
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extern cycles_t cacheflush_time; |
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static inline cycles_t get_cycles(void) |
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{ |
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cycles_t ret = 0; |
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__asm__ __volatile__( |
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"98: mftb %0\n" |
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"99:\n" |
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".section __ftr_fixup,\"a\"\n" |
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" .long %1\n" |
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" .long 0\n" |
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" .long 98b\n" |
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" .long 99b\n" |
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".previous" |
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: "=r" (ret) : "i" (CPU_FTR_601)); |
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return ret; |
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} |
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#endif |
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#ifdef __i386__ |
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typedef unsigned long long cycles_t; |
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extern cycles_t cacheflush_time; |
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#define rdtscll(val) \ |
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__asm__ __volatile__("rdtsc" : "=A" (val)) |
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static inline cycles_t get_cycles (void) |
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{ |
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unsigned long long ret; |
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rdtscll(ret); |
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return ret; |
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} |
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#endif |
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#endif |
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#endif // __FFADO_CYCLES_H__ |
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