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| author | Thomas Doerfler <Thomas.Doerfler@embedded-brains.de> | 2009-03-05 13:45:06 +0000 |
|---|---|---|
| committer | Thomas Doerfler <Thomas.Doerfler@embedded-brains.de> | 2009-03-05 13:45:06 +0000 |
| commit | 21ae805dc16ec6b78f2eb493bd2c4a2f830e9073 (patch) | |
| tree | 54c340829b88700cac85c89a1c027b1d65558fc8 | |
| parent | 2009-03-05 Sebastian Huber <sebastian.huber@embedded-brains.de> (diff) | |
| download | rtems-21ae805dc16ec6b78f2eb493bd2c4a2f830e9073.tar.bz2 | |
* shared/clock/clock.c: Standard decrementer exception is now more
robust against erroneous external exception disable times.
| -rw-r--r-- | c/src/lib/libbsp/powerpc/ChangeLog | 5 | ||||
| -rw-r--r-- | c/src/lib/libbsp/powerpc/shared/clock/clock.c | 61 |
2 files changed, 39 insertions, 27 deletions
diff --git a/c/src/lib/libbsp/powerpc/ChangeLog b/c/src/lib/libbsp/powerpc/ChangeLog index eaa508b0da..0a0696c5dd 100644 --- a/c/src/lib/libbsp/powerpc/ChangeLog +++ b/c/src/lib/libbsp/powerpc/ChangeLog @@ -1,3 +1,8 @@ +2009-03-05 Sebastian Huber <sebastian.huber@embedded-brains.de> + + * shared/clock/clock.c: Standard decrementer exception is now more + robust against erroneous external exception disable times. + 2009-02-27 Joel Sherrill <joel.sherrill@OARcorp.com> * shared/startup/bspgetworkarea.c: Add check to determine if current diff --git a/c/src/lib/libbsp/powerpc/shared/clock/clock.c b/c/src/lib/libbsp/powerpc/shared/clock/clock.c index 0baa9508d9..090c4d0f5c 100644 --- a/c/src/lib/libbsp/powerpc/shared/clock/clock.c +++ b/c/src/lib/libbsp/powerpc/shared/clock/clock.c @@ -7,15 +7,16 @@ */ /* - * Copyright (c) 2008 + * Copyright (c) 2008, 2009 * Embedded Brains GmbH * Obere Lagerstr. 30 * D-82178 Puchheim * Germany * rtems@embedded-brains.de * - * The license and distribution terms for this file may be found in the file - * LICENSE in this distribution or at http://www.rtems.com/license/LICENSE. + * The license and distribution terms for this file may be + * found in the file LICENSE in this distribution or at + * http://www.rtems.com/license/LICENSE. */ #include <rtems.h> @@ -57,34 +58,40 @@ static void (*ppc_clock_tick)(void) = ppc_clock_no_tick; static int ppc_clock_exception_handler( BSP_Exception_frame *frame, unsigned number) { - uint32_t reg1; - uint32_t reg2; - uint32_t reg3; - uint32_t msr; + uint32_t delta = ppc_clock_decrementer_value; + uint32_t next = ppc_clock_next_time_base; + uint32_t dec = 0; + uint32_t now = 0; + uint32_t msr = 0; - /* Set new decrementer value according to a reference time base */ - asm volatile ( - "lwz %0, ppc_clock_next_time_base@sdarel(13);" - "lwz %1, ppc_clock_decrementer_value@sdarel(13);" - "mftb %2;" - "add %0, %0, %1;" - "subf %1, %2, %0;" - "stw %0, ppc_clock_next_time_base@sdarel(13);" - "mtdec %1;" - : "=r" (reg1), "=r" (reg2), "=r" (reg3) - ); + do { + /* Increment clock ticks */ + Clock_driver_ticks += 1; - /* Increment clock ticks */ - Clock_driver_ticks += 1; + /* Enable external exceptions */ + msr = ppc_external_exceptions_enable(); - /* Enable external exceptions */ - msr = ppc_external_exceptions_enable(); + /* Call clock ticker */ + ppc_clock_tick(); - /* Call clock ticker */ - ppc_clock_tick(); + /* Restore machine state */ + ppc_external_exceptions_disable( msr); - /* Restore machine state */ - ppc_external_exceptions_disable( msr); + /* Next time base */ + next += delta; + + /* Current time */ + now = ppc_time_base(); + + /* New decrementer value */ + dec = next - now; + } while (dec > delta); + + /* Set decrementer */ + ppc_set_decrementer_register( dec); + + /* Expected next time base */ + ppc_clock_next_time_base = next; return 0; } @@ -201,7 +208,7 @@ rtems_device_driver Clock_initialize( rtems_device_major_number major, rtems_dev /* Check decrementer value */ if (ppc_clock_decrementer_value == 0) { ppc_clock_decrementer_value = PPC_CLOCK_DECREMENTER_MAX; - RTEMS_SYSLOG_ERROR( "Decrementer value would be zero, will be set to maximum value instead\n"); + RTEMS_SYSLOG_ERROR( "decrementer value would be zero, will be set to maximum value instead\n"); } /* Set the nanoseconds since last tick handler */ |