96 lines
		
	
	
	
		
			2.1 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
		
		
			
		
	
	
			96 lines
		
	
	
	
		
			2.1 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
|   | /*
 | ||
|  |  * POWER Data Stream Control Register (DSCR) fork test | ||
|  |  * | ||
|  |  * This testcase modifies the DSCR using mtspr, forks and then | ||
|  |  * verifies that the child process has the correct changed DSCR | ||
|  |  * value using mfspr. | ||
|  |  * | ||
|  |  * When using the privilege state SPR, the instructions such as | ||
|  |  * mfspr or mtspr are priviledged and the kernel emulates them | ||
|  |  * for us. Instructions using problem state SPR can be exuecuted | ||
|  |  * directly without any emulation if the HW supports them. Else | ||
|  |  * they also get emulated by the kernel. | ||
|  |  * | ||
|  |  * Copyright 2012, Anton Blanchard, IBM Corporation. | ||
|  |  * Copyright 2015, Anshuman Khandual, IBM Corporation. | ||
|  |  * | ||
|  |  * This program is free software; you can redistribute it and/or modify it | ||
|  |  * under the terms of the GNU General Public License version 2 as published | ||
|  |  * by the Free Software Foundation. | ||
|  |  */ | ||
|  | #include "dscr.h"
 | ||
|  | 
 | ||
|  | int dscr_inherit(void) | ||
|  | { | ||
|  | 	unsigned long i, dscr = 0; | ||
|  | 	pid_t pid; | ||
|  | 
 | ||
|  | 	srand(getpid()); | ||
|  | 	set_dscr(dscr); | ||
|  | 
 | ||
|  | 	for (i = 0; i < COUNT; i++) { | ||
|  | 		unsigned long cur_dscr, cur_dscr_usr; | ||
|  | 
 | ||
|  | 		dscr++; | ||
|  | 		if (dscr > DSCR_MAX) | ||
|  | 			dscr = 0; | ||
|  | 
 | ||
|  | 		if (i % 2 == 0) | ||
|  | 			set_dscr_usr(dscr); | ||
|  | 		else | ||
|  | 			set_dscr(dscr); | ||
|  | 
 | ||
|  | 		/*
 | ||
|  | 		 * XXX: Force a context switch out so that DSCR | ||
|  | 		 * current value is copied into the thread struct | ||
|  | 		 * which is required for the child to inherit the | ||
|  | 		 * changed value. | ||
|  | 		 */ | ||
|  | 		sleep(1); | ||
|  | 
 | ||
|  | 		pid = fork(); | ||
|  | 		if (pid == -1) { | ||
|  | 			perror("fork() failed"); | ||
|  | 			exit(1); | ||
|  | 		} else if (pid) { | ||
|  | 			int status; | ||
|  | 
 | ||
|  | 			if (waitpid(pid, &status, 0) == -1) { | ||
|  | 				perror("waitpid() failed"); | ||
|  | 				exit(1); | ||
|  | 			} | ||
|  | 
 | ||
|  | 			if (!WIFEXITED(status)) { | ||
|  | 				fprintf(stderr, "Child didn't exit cleanly\n"); | ||
|  | 				exit(1); | ||
|  | 			} | ||
|  | 
 | ||
|  | 			if (WEXITSTATUS(status) != 0) { | ||
|  | 				fprintf(stderr, "Child didn't exit cleanly\n"); | ||
|  | 				return 1; | ||
|  | 			} | ||
|  | 		} else { | ||
|  | 			cur_dscr = get_dscr(); | ||
|  | 			if (cur_dscr != dscr) { | ||
|  | 				fprintf(stderr, "Kernel DSCR should be %ld " | ||
|  | 					"but is %ld\n", dscr, cur_dscr); | ||
|  | 				exit(1); | ||
|  | 			} | ||
|  | 
 | ||
|  | 			cur_dscr_usr = get_dscr_usr(); | ||
|  | 			if (cur_dscr_usr != dscr) { | ||
|  | 				fprintf(stderr, "User DSCR should be %ld " | ||
|  | 					"but is %ld\n", dscr, cur_dscr_usr); | ||
|  | 				exit(1); | ||
|  | 			} | ||
|  | 			exit(0); | ||
|  | 		} | ||
|  | 	} | ||
|  | 	return 0; | ||
|  | } | ||
|  | 
 | ||
|  | int main(int argc, char *argv[]) | ||
|  | { | ||
|  | 	return test_harness(dscr_inherit, "dscr_inherit_test"); | ||
|  | } |