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author | 2015-08-28 09:58:54 +0800 | |
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committer | 2015-09-01 12:44:00 +0800 | |
commit | e44e3482bdb4d0ebde2d8b41830ac2cdb07948fb (patch) | |
tree | 66b09f592c55df2878107a468a91d21506104d3f /qemu/roms/ipxe/src/interface/efi/efi_timer.c | |
parent | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (diff) |
Add qemu 2.4.0
Change-Id: Ic99cbad4b61f8b127b7dc74d04576c0bcbaaf4f5
Signed-off-by: Yang Zhang <yang.z.zhang@intel.com>
Diffstat (limited to 'qemu/roms/ipxe/src/interface/efi/efi_timer.c')
-rw-r--r-- | qemu/roms/ipxe/src/interface/efi/efi_timer.c | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/qemu/roms/ipxe/src/interface/efi/efi_timer.c b/qemu/roms/ipxe/src/interface/efi/efi_timer.c new file mode 100644 index 000000000..7a1ff7869 --- /dev/null +++ b/qemu/roms/ipxe/src/interface/efi/efi_timer.c @@ -0,0 +1,124 @@ +/* + * 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. + */ + +FILE_LICENCE ( GPL2_OR_LATER ); + +#include <string.h> +#include <errno.h> +#include <limits.h> +#include <assert.h> +#include <unistd.h> +#include <ipxe/timer.h> +#include <ipxe/efi/efi.h> +#include <ipxe/efi/Protocol/Cpu.h> + +/** @file + * + * iPXE timer API for EFI + * + */ + +/** Scale factor to apply to CPU timer 0 + * + * The timer is scaled down in order to ensure that reasonable values + * for "number of ticks" don't exceed the size of an unsigned long. + */ +#define EFI_TIMER0_SHIFT 12 + +/** Calibration time */ +#define EFI_CALIBRATE_DELAY_MS 1 + +/** CPU protocol */ +static EFI_CPU_ARCH_PROTOCOL *cpu_arch; +EFI_REQUIRE_PROTOCOL ( EFI_CPU_ARCH_PROTOCOL, &cpu_arch ); + +/** + * Delay for a fixed number of microseconds + * + * @v usecs Number of microseconds for which to delay + */ +static void efi_udelay ( unsigned long usecs ) { + EFI_BOOT_SERVICES *bs = efi_systab->BootServices; + EFI_STATUS efirc; + int rc; + + if ( ( efirc = bs->Stall ( usecs ) ) != 0 ) { + rc = -EEFI ( efirc ); + DBG ( "EFI could not delay for %ldus: %s\n", + usecs, strerror ( rc ) ); + /* Probably screwed */ + } +} + +/** + * Get current system time in ticks + * + * @ret ticks Current time, in ticks + */ +static unsigned long efi_currticks ( void ) { + UINT64 time; + EFI_STATUS efirc; + int rc; + + /* Read CPU timer 0 (TSC) */ + if ( ( efirc = cpu_arch->GetTimerValue ( cpu_arch, 0, &time, + NULL ) ) != 0 ) { + rc = -EEFI ( efirc ); + DBG ( "EFI could not read CPU timer: %s\n", strerror ( rc ) ); + /* Probably screwed */ + return -1UL; + } + + return ( time >> EFI_TIMER0_SHIFT ); +} + +/** + * Get number of ticks per second + * + * @ret ticks_per_sec Number of ticks per second + */ +static unsigned long efi_ticks_per_sec ( void ) { + static unsigned long ticks_per_sec = 0; + + /* Calibrate timer, if necessary. EFI does nominally provide + * the timer speed via the (optional) TimerPeriod parameter to + * the GetTimerValue() call, but it gets the speed slightly + * wrong. By up to three orders of magnitude. Not helpful. + */ + if ( ! ticks_per_sec ) { + unsigned long start; + unsigned long elapsed; + + DBG ( "Calibrating EFI timer with a %d ms delay\n", + EFI_CALIBRATE_DELAY_MS ); + start = currticks(); + mdelay ( EFI_CALIBRATE_DELAY_MS ); + elapsed = ( currticks() - start ); + ticks_per_sec = ( elapsed * ( 1000 / EFI_CALIBRATE_DELAY_MS )); + DBG ( "EFI CPU timer calibrated at %ld ticks in %d ms (%ld " + "ticks/sec)\n", elapsed, EFI_CALIBRATE_DELAY_MS, + ticks_per_sec ); + } + + return ticks_per_sec; +} + +PROVIDE_TIMER ( efi, udelay, efi_udelay ); +PROVIDE_TIMER ( efi, currticks, efi_currticks ); +PROVIDE_TIMER ( efi, ticks_per_sec, efi_ticks_per_sec ); |