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- /*
- * Copyright (C) 2014 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
- *
- * Real mode transition self-tests
- *
- * This file allows for easy measurement of the time taken to perform
- * real mode transitions, which may have a substantial overhead when
- * running under a hypervisor.
- *
- */
-
- /* Forcibly enable assertions */
- #undef NDEBUG
-
- #include <ipxe/test.h>
- #include <ipxe/profile.h>
- #include <realmode.h>
-
- /** Number of sample iterations for profiling */
- #define PROFILE_COUNT 4096
-
- /** Protected-to-real mode transition profiler */
- static struct profiler p2r_profiler __profiler = { .name = "p2r" };
-
- /** Real-to-protected mode transition profiler */
- static struct profiler r2p_profiler __profiler = { .name = "r2p" };
-
- /** Real-mode call profiler */
- static struct profiler real_call_profiler __profiler = { .name = "real_call" };
-
- /** Virtual call profiler */
- static struct profiler virt_call_profiler __profiler = { .name = "virt_call" };
-
- /**
- * Dummy function for profiling tests
- */
- static __asmcall void librm_test_call ( struct i386_all_regs *ix86 __unused ) {
- /* Do nothing */
- }
-
- /**
- * Perform real mode transition self-tests
- *
- */
- static void librm_test_exec ( void ) {
- unsigned int i;
- unsigned long timestamp;
- uint32_t timestamp_lo;
- uint32_t timestamp_hi;
- uint32_t started;
- uint32_t stopped;
- uint32_t discard_d;
-
- /* Profile mode transitions. We want to profile each
- * direction of the transition separately, so perform an RDTSC
- * while in real mode and tweak the profilers' start/stop
- * times appropriately.
- */
- for ( i = 0 ; i < PROFILE_COUNT ; i++ ) {
- profile_start ( &p2r_profiler );
- __asm__ __volatile__ ( REAL_CODE ( "rdtsc\n\t" )
- : "=a" ( timestamp_lo ),
- "=d" ( timestamp_hi )
- : );
- timestamp = timestamp_lo;
- if ( sizeof ( timestamp ) > sizeof ( timestamp_lo ) )
- timestamp |= ( ( ( uint64_t ) timestamp_hi ) << 32 );
- profile_start_at ( &r2p_profiler, timestamp );
- profile_stop ( &r2p_profiler );
- profile_stop_at ( &p2r_profiler, timestamp );
- }
-
- /* Profile complete real-mode call cycle */
- for ( i = 0 ; i < PROFILE_COUNT ; i++ ) {
- profile_start ( &real_call_profiler );
- __asm__ __volatile__ ( REAL_CODE ( "" ) );
- profile_stop ( &real_call_profiler );
- }
-
- /* Profile complete virtual call cycle */
- for ( i = 0 ; i < PROFILE_COUNT ; i++ ) {
- __asm__ __volatile__ ( REAL_CODE ( "rdtsc\n\t"
- "movl %k0, %k2\n\t"
- VIRT_CALL ( librm_test_call )
- "rdtsc\n\t" )
- : "=a" ( stopped ), "=d" ( discard_d ),
- "=R" ( started ) : );
- profile_start_at ( &virt_call_profiler, started );
- profile_stop_at ( &virt_call_profiler, stopped );
- }
- }
-
- /** Real mode transition self-test */
- struct self_test librm_test __self_test = {
- .name = "librm",
- .exec = librm_test_exec,
- };
-
- REQUIRING_SYMBOL ( librm_test );
- REQUIRE_OBJECT ( test );
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