[444] | 1 | /* |
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| 2 | (C) Copyright IBM Corp. 2008 |
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| 3 | |
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| 4 | All rights reserved. |
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| 5 | |
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| 6 | Redistribution and use in source and binary forms, with or without |
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| 7 | modification, are permitted provided that the following conditions are met: |
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| 8 | |
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| 9 | * Redistributions of source code must retain the above copyright notice, |
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| 10 | this list of conditions and the following disclaimer. |
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| 11 | * Redistributions in binary form must reproduce the above copyright |
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| 12 | notice, this list of conditions and the following disclaimer in the |
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| 13 | documentation and/or other materials provided with the distribution. |
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| 14 | * Neither the name of IBM nor the names of its contributors may be |
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| 15 | used to endorse or promote products derived from this software without |
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| 16 | specific prior written permission. |
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| 17 | |
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| 18 | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
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| 19 | AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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| 20 | IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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| 21 | ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE |
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| 22 | LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
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| 23 | CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
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| 24 | SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
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| 25 | INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
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| 26 | CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
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| 27 | ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
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| 28 | POSSIBILITY OF SUCH DAMAGE. |
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| 29 | */ |
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| 30 | |
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| 31 | /* SPU clock start and read library services. */ |
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| 32 | #include <spu_timer.h> |
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| 33 | #include "spu_timer_internal.h" |
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| 34 | |
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| 35 | /* The software managed timebase value. */ |
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| 36 | volatile uint64_t __spu_tb_val __attribute__ ((aligned (16))); |
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| 37 | |
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| 38 | /* Timeout value of the current interval. */ |
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| 39 | volatile int __spu_tb_timeout __attribute__ ((aligned (16))); |
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| 40 | |
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| 41 | /* Clock start count (clock is running if >0). */ |
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| 42 | volatile unsigned __spu_clock_startcnt __attribute__ ((aligned (16))); |
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| 43 | |
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| 44 | /* Saved interrupt state from clock_start. */ |
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| 45 | volatile unsigned __spu_clock_state_was_enabled; |
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| 46 | |
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| 47 | /* Initializes the software managed timebase, enables the decrementer event, |
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| 48 | starts the decrementer and enables interrupts. Must be called before |
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| 49 | clock or timer services can be used. Should only be called by base app/lib |
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| 50 | code (not from an interrupt/timer handler). |
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| 51 | Returns with interrupts ENABLED. */ |
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| 52 | void |
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| 53 | spu_clock_start (void) |
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| 54 | { |
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| 55 | /* Increment clock start and return if it was already running. */ |
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| 56 | if (++__spu_clock_startcnt > 1) |
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| 57 | return; |
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| 58 | |
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| 59 | __spu_clock_state_was_enabled = spu_readch (SPU_RdMachStat) & 0x1; |
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| 60 | |
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| 61 | spu_idisable (); |
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| 62 | __spu_tb_timeout = CLOCK_START_VALUE; |
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| 63 | __spu_tb_val = 0; |
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| 64 | |
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| 65 | /* Disable, write, enable the decrementer. */ |
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| 66 | __enable_spu_decr (__spu_tb_timeout, __disable_spu_decr ()); |
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| 67 | |
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| 68 | spu_ienable (); |
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| 69 | |
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| 70 | return; |
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| 71 | } |
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| 72 | |
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| 73 | /* Returns a monotonically increasing, 64-bit counter, in timebase units, |
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| 74 | relative to the last call to spu_clock_start(). */ |
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| 75 | uint64_t |
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| 76 | spu_clock_read (void) |
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| 77 | { |
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| 78 | int64_t time; |
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| 79 | unsigned was_enabled; |
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| 80 | |
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| 81 | /* Return 0 if clock is off. */ |
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| 82 | if (__spu_clock_startcnt == 0) |
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| 83 | return 0LL; |
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| 84 | |
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| 85 | was_enabled = spu_readch (SPU_RdMachStat) & 0x1; |
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| 86 | spu_idisable (); |
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| 87 | |
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| 88 | time = __spu_tb_val + (__spu_tb_timeout - spu_readch (SPU_RdDec)); |
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| 89 | |
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| 90 | if (__likely (was_enabled)) |
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| 91 | spu_ienable (); |
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| 92 | return time; |
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| 93 | } |
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