diff options
Diffstat (limited to 'qemu/roms/ipxe/src/arch/i386/core/rdtsc_timer.c')
-rw-r--r-- | qemu/roms/ipxe/src/arch/i386/core/rdtsc_timer.c | 94 |
1 files changed, 0 insertions, 94 deletions
diff --git a/qemu/roms/ipxe/src/arch/i386/core/rdtsc_timer.c b/qemu/roms/ipxe/src/arch/i386/core/rdtsc_timer.c deleted file mode 100644 index e720a239c..000000000 --- a/qemu/roms/ipxe/src/arch/i386/core/rdtsc_timer.c +++ /dev/null @@ -1,94 +0,0 @@ -/* - * Copyright (C) 2008 Michael Brown <mbrown@fensystems.co.uk>. - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License as - * published by the Free Software Foundation; either version 2 of the - * License, or any later version. - * - * This program is distributed in the hope that it will be useful, but - * WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA - * 02110-1301, USA. - * - * You can also choose to distribute this program under the terms of - * the Unmodified Binary Distribution Licence (as given in the file - * COPYING.UBDL), provided that you have satisfied its requirements. - */ - -FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL ); - -/** @file - * - * RDTSC timer - * - */ - -#include <assert.h> -#include <ipxe/timer.h> -#include <ipxe/pit8254.h> - -/** - * Number of TSC ticks per microsecond - * - * This is calibrated on the first use of the timer. - */ -static unsigned long rdtsc_ticks_per_usec; - -/** - * Delay for a fixed number of microseconds - * - * @v usecs Number of microseconds for which to delay - */ -static void rdtsc_udelay ( unsigned long usecs ) { - unsigned long start; - unsigned long elapsed; - - /* Sanity guard, since we may divide by this */ - if ( ! usecs ) - usecs = 1; - - start = currticks(); - if ( rdtsc_ticks_per_usec ) { - /* Already calibrated; busy-wait until done */ - do { - elapsed = ( currticks() - start ); - } while ( elapsed < ( usecs * rdtsc_ticks_per_usec ) ); - } else { - /* Not yet calibrated; use 8254 PIT and calibrate - * based on result. - */ - pit8254_udelay ( usecs ); - elapsed = ( currticks() - start ); - rdtsc_ticks_per_usec = ( elapsed / usecs ); - DBG ( "RDTSC timer calibrated: %ld ticks in %ld usecs " - "(%ld MHz)\n", elapsed, usecs, - ( rdtsc_ticks_per_usec << TSC_SHIFT ) ); - } -} - -/** - * Get number of ticks per second - * - * @ret ticks_per_sec Number of ticks per second - */ -static unsigned long rdtsc_ticks_per_sec ( void ) { - - /* Calibrate timer, if not already done */ - if ( ! rdtsc_ticks_per_usec ) - udelay ( 1 ); - - /* Sanity check */ - assert ( rdtsc_ticks_per_usec != 0 ); - - return ( rdtsc_ticks_per_usec * 1000 * 1000 ); -} - -PROVIDE_TIMER ( rdtsc, udelay, rdtsc_udelay ); -PROVIDE_TIMER_INLINE ( rdtsc, currticks ); -PROVIDE_TIMER ( rdtsc, ticks_per_sec, rdtsc_ticks_per_sec ); |