| /* |
| (C) Copyright IBM Corp. 2008 |
| |
| All rights reserved. |
| |
| Redistribution and use in source and binary forms, with or without |
| modification, are permitted provided that the following conditions are met: |
| |
| * Redistributions of source code must retain the above copyright notice, |
| this list of conditions and the following disclaimer. |
| * Redistributions in binary form must reproduce the above copyright |
| notice, this list of conditions and the following disclaimer in the |
| documentation and/or other materials provided with the distribution. |
| * Neither the name of IBM nor the names of its contributors may be |
| used to endorse or promote products derived from this software without |
| specific prior written permission. |
| |
| THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
| AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE |
| LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| /* SPU clock start and read library services. */ |
| #include <spu_timer.h> |
| #include "spu_timer_internal.h" |
| |
| /* The software managed timebase value. */ |
| volatile uint64_t __spu_tb_val __attribute__ ((aligned (16))); |
| |
| /* Timeout value of the current interval. */ |
| volatile int __spu_tb_timeout __attribute__ ((aligned (16))); |
| |
| /* Clock start count (clock is running if >0). */ |
| volatile unsigned __spu_clock_startcnt __attribute__ ((aligned (16))); |
| |
| /* Saved interrupt state from clock_start. */ |
| volatile unsigned __spu_clock_state_was_enabled; |
| |
| /* Initializes the software managed timebase, enables the decrementer event, |
| starts the decrementer and enables interrupts. Must be called before |
| clock or timer services can be used. Should only be called by base app/lib |
| code (not from an interrupt/timer handler). |
| Returns with interrupts ENABLED. */ |
| void |
| spu_clock_start (void) |
| { |
| /* Increment clock start and return if it was already running. */ |
| if (++__spu_clock_startcnt > 1) |
| return; |
| |
| __spu_clock_state_was_enabled = spu_readch (SPU_RdMachStat) & 0x1; |
| |
| spu_idisable (); |
| __spu_tb_timeout = CLOCK_START_VALUE; |
| __spu_tb_val = 0; |
| |
| /* Disable, write, enable the decrementer. */ |
| __enable_spu_decr (__spu_tb_timeout, __disable_spu_decr ()); |
| |
| spu_ienable (); |
| |
| return; |
| } |
| |
| /* Returns a monotonically increasing, 64-bit counter, in timebase units, |
| relative to the last call to spu_clock_start(). */ |
| uint64_t |
| spu_clock_read (void) |
| { |
| int64_t time; |
| unsigned was_enabled; |
| |
| /* Return 0 if clock is off. */ |
| if (__spu_clock_startcnt == 0) |
| return 0LL; |
| |
| was_enabled = spu_readch (SPU_RdMachStat) & 0x1; |
| spu_idisable (); |
| |
| time = __spu_tb_val + (__spu_tb_timeout - spu_readch (SPU_RdDec)); |
| |
| if (__likely (was_enabled)) |
| spu_ienable (); |
| return time; |
| } |