From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lists.s-osg.org (lists.s-osg.org [54.187.51.154]) by lists.ozlabs.org (Postfix) with ESMTP id 636131A0723 for ; Wed, 14 Jan 2015 02:22:59 +1100 (AEDT) Message-ID: <54B5384F.9010805@osg.samsung.com> Date: Tue, 13 Jan 2015 08:22:55 -0700 From: Shuah Khan MIME-Version: 1.0 To: Anshuman Khandual , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH V2 06/12] selftests, powerpc: Add test for system wide DSCR default References: <1421144560-15901-1-git-send-email-khandual@linux.vnet.ibm.com> <1421144560-15901-7-git-send-email-khandual@linux.vnet.ibm.com> In-Reply-To: <1421144560-15901-7-git-send-email-khandual@linux.vnet.ibm.com> Content-Type: text/plain; charset=windows-1252 Cc: mikey@neuling.org, anton@samba.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 01/13/2015 03:22 AM, Anshuman Khandual wrote: > This patch adds a test case for the system wide DSCR default > value, which when changed through it's sysfs interface must > be visible to all threads reading DSCR either through the > privilege state SPR or the problem state SPR. The DSCR value > change should be immediate as well. > > Signed-off-by: Anshuman Khandual > --- > tools/testing/selftests/powerpc/Makefile | 2 +- > tools/testing/selftests/powerpc/dscr/Makefile | 17 +++ > tools/testing/selftests/powerpc/dscr/dscr.h | 120 ++++++++++++++++++++ > .../selftests/powerpc/dscr/dscr_default_test.c | 121 +++++++++++++++++++++ > 4 files changed, 259 insertions(+), 1 deletion(-) > create mode 100644 tools/testing/selftests/powerpc/dscr/Makefile > create mode 100644 tools/testing/selftests/powerpc/dscr/dscr.h > create mode 100644 tools/testing/selftests/powerpc/dscr/dscr_default_test.c > > diff --git a/tools/testing/selftests/powerpc/Makefile b/tools/testing/selftests/powerpc/Makefile > index f6ff90a..1318883 100644 > --- a/tools/testing/selftests/powerpc/Makefile > +++ b/tools/testing/selftests/powerpc/Makefile > @@ -13,7 +13,7 @@ CFLAGS := -Wall -O2 -flto -Wall -Werror -DGIT_VERSION='"$(GIT_VERSION)"' -I$(CUR > > export CC CFLAGS > > -TARGETS = pmu copyloops mm tm primitives > +TARGETS = pmu copyloops mm tm primitives dscr > > endif > > diff --git a/tools/testing/selftests/powerpc/dscr/Makefile b/tools/testing/selftests/powerpc/dscr/Makefile > new file mode 100644 > index 0000000..0aa90ab > --- /dev/null > +++ b/tools/testing/selftests/powerpc/dscr/Makefile > @@ -0,0 +1,17 @@ > +PROGS := dscr_default_test > + > +CFLAGS := $(CFLAGS) -lpthread > + > +all: $(PROGS) > + > +$(PROGS): ../harness.c > + > +run_tests: all > + @-for PROG in $(PROGS); do \ > + ./$$PROG; \ > + done; > + > +clean: > + rm -f $(PROGS) *.o > + > +.PHONY: all run_tests clean > diff --git a/tools/testing/selftests/powerpc/dscr/dscr.h b/tools/testing/selftests/powerpc/dscr/dscr.h > new file mode 100644 > index 0000000..2e6535b > --- /dev/null > +++ b/tools/testing/selftests/powerpc/dscr/dscr.h > @@ -0,0 +1,120 @@ > +/* > + * POWER Data Stream Control Register (DSCR) > + * > + * This header file contains helper functions and macros > + * required for all the DSCR related test cases. > + * > + * Copyright (C) 2012 Anton Blanchard , IBM > + * Copyright (C) 2015 Anshuman Khandual , IBM > + * > + * 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 (at your option) any later version. > + */ > +#ifndef _SELFTESTS_POWERPC_DSCR_DSCR_H > +#define _SELFTESTS_POWERPC_DSCR_DSCR_H > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#include "utils.h" > + > +#define SPRN_DSCR 0x11 /* Privilege state SPR */ > +#define SPRN_DSCR_USR 0x03 /* Problem state SPR */ > +#define THREADS 100 /* Max threads */ > +#define COUNT 100 /* Max iterations */ > +#define DSCR_MAX 16 /* Max DSCR value */ > +#define LEN_MAX 100 /* Max name length */ > + > +#define DSCR_DEFAULT "/sys/devices/system/cpu/dscr_default" > +#define CPU_PATH "/sys/devices/system/cpu/" > + > +#define rmb() asm volatile("lwsync":::"memory") > +#define wmb() asm volatile("lwsync":::"memory") > + > +#define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x)) > + > +/* Prilvilege state DSCR access */ > +inline unsigned long get_dscr(void) > +{ > + unsigned long ret; > + > + asm volatile("mfspr %0,%1" : "=r" (ret): "i" (SPRN_DSCR)); > + > + return ret; > +} > + > +inline void set_dscr(unsigned long val) > +{ > + asm volatile("mtspr %1,%0" : : "r" (val), "i" (SPRN_DSCR)); > +} > + > +/* Problem state DSCR access */ > +inline unsigned long get_dscr_usr(void) > +{ > + unsigned long ret; > + > + asm volatile("mfspr %0,%1" : "=r" (ret): "i" (SPRN_DSCR_USR)); > + > + return ret; > +} > + > +inline void set_dscr_usr(unsigned long val) > +{ > + asm volatile("mtspr %1,%0" : : "r" (val), "i" (SPRN_DSCR_USR)); > +} > + > +/* Default DSCR access */ > +unsigned long get_default_dscr(void) > +{ > + int fd = -1; > + char buf[16]; > + unsigned long val; > + > + if (fd == -1) { > + fd = open(DSCR_DEFAULT, O_RDONLY); > + if (fd == -1) { > + perror("open() failed\n"); > + exit(1); > + } > + } > + memset(buf, 0, sizeof(buf)); > + lseek(fd, 0, SEEK_SET); > + read(fd, buf, sizeof(buf)); > + sscanf(buf, "%lx", &val); > + close(fd); > + return val; > +} > + > +void set_default_dscr(unsigned long val) > +{ > + int fd = -1; > + char buf[16]; > + > + if (fd == -1) { > + fd = open(DSCR_DEFAULT, O_RDWR); > + if (fd == -1) { > + perror("open() failed\n"); > + exit(1); > + } > + } > + sprintf(buf, "%lx\n", val); > + write(fd, buf, strlen(buf)); > + close(fd); > +} > + > +double uniform_deviate(int seed) > +{ > + return seed * (1.0 / (RAND_MAX + 1.0)); > +} > +#endif /* _SELFTESTS_POWERPC_DSCR_DSCR_H */ > diff --git a/tools/testing/selftests/powerpc/dscr/dscr_default_test.c b/tools/testing/selftests/powerpc/dscr/dscr_default_test.c > new file mode 100644 > index 0000000..fd8b7b9 > --- /dev/null > +++ b/tools/testing/selftests/powerpc/dscr/dscr_default_test.c > @@ -0,0 +1,121 @@ > +/* > + * POWER Data Stream Control Register (DSCR) default test > + * > + * This test modifies the system wide default DSCR through > + * it's sysfs interface and then verifies that all threads > + * see the correct changed DSCR value immediately. > + * > + * Copyright (C) 2012 Anton Blanchard , IBM > + * Copyright (C) 2015 Anshuman Khandual , IBM > + * > + * 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 (at your option) any later version. > + */ > +#include "dscr.h" > + > +static unsigned long dscr; /* System DSCR default */ > +static unsigned long sequence; > +static unsigned long result[THREADS]; > + > +static void *do_test(void *in) > +{ > + unsigned long thread = (unsigned long)in; > + unsigned long i; > + > + for (i = 0; i < COUNT; i++) { > + unsigned long d, cur_dscr, cur_dscr_usr; > + unsigned long s1, s2; > + > + s1 = ACCESS_ONCE(sequence); > + if (s1 & 1) > + continue; > + rmb(); > + > + d = dscr; > + cur_dscr = get_dscr(); > + cur_dscr_usr = get_dscr_usr(); > + > + rmb(); > + s2 = sequence; > + > + if (s1 != s2) > + continue; > + > + if (cur_dscr != d) { > + fprintf(stderr, "thread %ld kernel DSCR should be %ld " > + "but is %ld\n", thread, d, cur_dscr); > + result[thread] = 1; > + pthread_exit(&result[thread]); > + } > + > + if (cur_dscr_usr != d) { > + fprintf(stderr, "thread %ld user DSCR should be %ld " > + "but is %ld\n", thread, d, cur_dscr_usr); > + result[thread] = 1; > + pthread_exit(&result[thread]); > + } > + } > + result[thread] = 0; > + pthread_exit(&result[thread]); > +} > + > +int test_body(void) > +{ > + pthread_t threads[THREADS]; > + unsigned long i, *status[THREADS]; > + > + /* Initial DSCR default */ > + dscr = 1; > + set_default_dscr(dscr); > + > + /* Spawn all testing threads */ > + for (i = 0; i < THREADS; i++) { > + if (pthread_create(&threads[i], NULL, do_test, (void *)i)) { > + perror("pthread_create() failed\n"); > + exit(1); > + } > + } > + > + srand(getpid()); > + > + /* Keep changing the DSCR default */ > + for (i = 0; i < COUNT; i++) { > + double ret = uniform_deviate(rand()); > + > + if (ret < 0.0001) { > + sequence++; > + wmb(); > + > + dscr++; > + if (dscr > DSCR_MAX) > + dscr = 0; > + > + set_default_dscr(dscr); > + > + wmb(); > + sequence++; > + } > + } > + > + /* Individual testing thread exit status */ > + for (i = 0; i < THREADS; i++) { > + if (pthread_join(threads[i], (void **)&(status[i]))) { > + perror("pthread_join() failed\n"); > + exit(1); > + } > + > + if (*status[i]) { > + printf("%ldth thread failed to join with %ld status\n", > + i, *status[i]); > + return 1; > + } > + } > + return 0; > +} > + > +int main(int argc, char *argv[]) > +{ > + return test_harness(test_body, "dscr_default_test"); > +} > Could you please add a .gitignore for powerpc targets as we discussed earlier. It can be separate patch. Also, I would like to see the test results reports using kselftest.h - it can be separate patch in the interest of getting tests in. Acked-by: Shuah Khan Please take this through powerpc maintainer git. thanks, -- Shuah -- Shuah Khan Sr. Linux Kernel Developer Open Source Innovation Group Samsung Research America (Silicon Valley) shuahkh@osg.samsung.com | (970) 217-8978