From e5ab8be68e4421d7f8d4e69e2a8ddb3d69508d2a Mon Sep 17 00:00:00 2001 From: Cyril Bur Date: Mon, 29 Feb 2016 17:53:44 +1100 Subject: [PATCH] selftests/powerpc: Test preservation of FPU and VMX regs across preemption Loop in assembly checking the registers with many threads. Signed-off-by: Cyril Bur Signed-off-by: Michael Ellerman --- .../testing/selftests/powerpc/math/.gitignore | 2 + tools/testing/selftests/powerpc/math/Makefile | 5 +- .../testing/selftests/powerpc/math/fpu_asm.S | 37 ++++++ .../selftests/powerpc/math/fpu_preempt.c | 113 ++++++++++++++++++ .../testing/selftests/powerpc/math/vmx_asm.S | 44 ++++++- .../selftests/powerpc/math/vmx_preempt.c | 112 +++++++++++++++++ 6 files changed, 310 insertions(+), 3 deletions(-) create mode 100644 tools/testing/selftests/powerpc/math/fpu_preempt.c create mode 100644 tools/testing/selftests/powerpc/math/vmx_preempt.c diff --git a/tools/testing/selftests/powerpc/math/.gitignore b/tools/testing/selftests/powerpc/math/.gitignore index b19b2694bd00..1a6f09ee85be 100644 --- a/tools/testing/selftests/powerpc/math/.gitignore +++ b/tools/testing/selftests/powerpc/math/.gitignore @@ -1,2 +1,4 @@ fpu_syscall vmx_syscall +fpu_preempt +vmx_preempt diff --git a/tools/testing/selftests/powerpc/math/Makefile b/tools/testing/selftests/powerpc/math/Makefile index 418bef192eab..b6f415805701 100644 --- a/tools/testing/selftests/powerpc/math/Makefile +++ b/tools/testing/selftests/powerpc/math/Makefile @@ -1,4 +1,4 @@ -TEST_PROGS := fpu_syscall vmx_syscall +TEST_PROGS := fpu_syscall fpu_preempt vmx_syscall vmx_preempt all: $(TEST_PROGS) @@ -6,7 +6,10 @@ $(TEST_PROGS): ../harness.c $(TEST_PROGS): CFLAGS += -O2 -g -pthread -m64 -maltivec fpu_syscall: fpu_asm.S +fpu_preempt: fpu_asm.S + vmx_syscall: vmx_asm.S +vmx_preempt: vmx_asm.S include ../../lib.mk diff --git a/tools/testing/selftests/powerpc/math/fpu_asm.S b/tools/testing/selftests/powerpc/math/fpu_asm.S index 7617da3117ba..f3711d80e709 100644 --- a/tools/testing/selftests/powerpc/math/fpu_asm.S +++ b/tools/testing/selftests/powerpc/math/fpu_asm.S @@ -159,3 +159,40 @@ FUNC_START(test_fpu) POP_BASIC_STACK(256) blr FUNC_END(test_fpu) + +# int preempt_fpu(double *darray, int *threads_running, int *running) +# On starting will (atomically) decrement not_ready as a signal that the FPU +# has been loaded with darray. Will proceed to check the validity of the FPU +# registers while running is not zero. +FUNC_START(preempt_fpu) + PUSH_BASIC_STACK(256) + std r3,STACK_FRAME_PARAM(0)(sp) # double *darray + std r4,STACK_FRAME_PARAM(1)(sp) # int *threads_starting + std r5,STACK_FRAME_PARAM(2)(sp) # int *running + PUSH_FPU(STACK_FRAME_LOCAL(3,0)) + + bl load_fpu + nop + + sync + # Atomic DEC + ld r3,STACK_FRAME_PARAM(1)(sp) +1: lwarx r4,0,r3 + addi r4,r4,-1 + stwcx. r4,0,r3 + bne- 1b + +2: ld r3,STACK_FRAME_PARAM(0)(sp) + bl check_fpu + nop + cmpdi r3,0 + bne 3f + ld r4,STACK_FRAME_PARAM(2)(sp) + ld r5,0(r4) + cmpwi r5,0 + bne 2b + +3: POP_FPU(STACK_FRAME_LOCAL(3,0)) + POP_BASIC_STACK(256) + blr +FUNC_END(preempt_fpu) diff --git a/tools/testing/selftests/powerpc/math/fpu_preempt.c b/tools/testing/selftests/powerpc/math/fpu_preempt.c new file mode 100644 index 000000000000..0f85b79d883d --- /dev/null +++ b/tools/testing/selftests/powerpc/math/fpu_preempt.c @@ -0,0 +1,113 @@ +/* + * Copyright 2015, Cyril Bur, IBM Corp. + * + * 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. + * + * This test attempts to see if the FPU registers change across preemption. + * Two things should be noted here a) The check_fpu function in asm only checks + * the non volatile registers as it is reused from the syscall test b) There is + * no way to be sure preemption happened so this test just uses many threads + * and a long wait. As such, a successful test doesn't mean much but a failure + * is bad. + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#include "utils.h" + +/* Time to wait for workers to get preempted (seconds) */ +#define PREEMPT_TIME 20 +/* + * Factor by which to multiply number of online CPUs for total number of + * worker threads + */ +#define THREAD_FACTOR 8 + + +__thread double darray[] = {0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, + 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, + 2.1}; + +int threads_starting; +int running; + +extern void preempt_fpu(double *darray, int *threads_starting, int *running); + +void *preempt_fpu_c(void *p) +{ + int i; + srand(pthread_self()); + for (i = 0; i < 21; i++) + darray[i] = rand(); + + /* Test failed if it ever returns */ + preempt_fpu(darray, &threads_starting, &running); + + return p; +} + +int test_preempt_fpu(void) +{ + int i, rc, threads; + pthread_t *tids; + + threads = sysconf(_SC_NPROCESSORS_ONLN) * THREAD_FACTOR; + tids = malloc((threads) * sizeof(pthread_t)); + FAIL_IF(!tids); + + running = true; + threads_starting = threads; + for (i = 0; i < threads; i++) { + rc = pthread_create(&tids[i], NULL, preempt_fpu_c, NULL); + FAIL_IF(rc); + } + + setbuf(stdout, NULL); + /* Not really necessary but nice to wait for every thread to start */ + printf("\tWaiting for all workers to start..."); + while(threads_starting) + asm volatile("": : :"memory"); + printf("done\n"); + + printf("\tWaiting for %d seconds to let some workers get preempted...", PREEMPT_TIME); + sleep(PREEMPT_TIME); + printf("done\n"); + + printf("\tStopping workers..."); + /* + * Working are checking this value every loop. In preempt_fpu 'cmpwi r5,0; bne 2b'. + * r5 will have loaded the value of running. + */ + running = 0; + for (i = 0; i < threads; i++) { + void *rc_p; + pthread_join(tids[i], &rc_p); + + /* + * Harness will say the fail was here, look at why preempt_fpu + * returned + */ + if ((long) rc_p) + printf("oops\n"); + FAIL_IF((long) rc_p); + } + printf("done\n"); + + free(tids); + return 0; +} + +int main(int argc, char *argv[]) +{ + return test_harness(test_preempt_fpu, "fpu_preempt"); +} diff --git a/tools/testing/selftests/powerpc/math/vmx_asm.S b/tools/testing/selftests/powerpc/math/vmx_asm.S index 4ce64212d5e0..1b8c248b3ac1 100644 --- a/tools/testing/selftests/powerpc/math/vmx_asm.S +++ b/tools/testing/selftests/powerpc/math/vmx_asm.S @@ -9,6 +9,7 @@ #include "../basic_asm.h" +# POS MUST BE 16 ALIGNED! #define PUSH_VMX(pos,reg) \ li reg,pos; \ stvx v20,reg,sp; \ @@ -35,6 +36,7 @@ addi reg,reg,16; \ stvx v31,reg,sp; +# POS MUST BE 16 ALIGNED! #define POP_VMX(pos,reg) \ li reg,pos; \ lvx v20,reg,sp; \ @@ -93,7 +95,7 @@ FUNC_END(load_vmx) # Should be safe from C, only touches r4, r5 and v0,v1,v2 FUNC_START(check_vmx) - PUSH_BASIC_STACK(16) + PUSH_BASIC_STACK(32) mr r4,r3 li r3,1 # assume a bad result li r5,0 @@ -162,7 +164,7 @@ FUNC_START(check_vmx) cmpdi r0,0xffffffffffffffff bne 1f li r3,0 -1: POP_BASIC_STACK(16) +1: POP_BASIC_STACK(32) blr FUNC_END(check_vmx) @@ -193,3 +195,41 @@ FUNC_START(test_vmx) POP_BASIC_STACK(512) blr FUNC_END(test_vmx) + +# int preempt_vmx(vector int *varray, int *threads_starting, int *running) +# On starting will (atomically) decrement threads_starting as a signal that +# the VMX have been loaded with varray. Will proceed to check the validity of +# the VMX registers while running is not zero. +FUNC_START(preempt_vmx) + PUSH_BASIC_STACK(512) + std r3,STACK_FRAME_PARAM(0)(sp) # vector int *varray + std r4,STACK_FRAME_PARAM(1)(sp) # int *threads_starting + std r5,STACK_FRAME_PARAM(2)(sp) # int *running + # VMX need to write to 16 byte aligned addresses, skip STACK_FRAME_LOCAL(3,0) + PUSH_VMX(STACK_FRAME_LOCAL(4,0),r4) + + bl load_vmx + nop + + sync + # Atomic DEC + ld r3,STACK_FRAME_PARAM(1)(sp) +1: lwarx r4,0,r3 + addi r4,r4,-1 + stwcx. r4,0,r3 + bne- 1b + +2: ld r3,STACK_FRAME_PARAM(0)(sp) + bl check_vmx + nop + cmpdi r3,0 + bne 3f + ld r4,STACK_FRAME_PARAM(2)(sp) + ld r5,0(r4) + cmpwi r5,0 + bne 2b + +3: POP_VMX(STACK_FRAME_LOCAL(4,0),r4) + POP_BASIC_STACK(512) + blr +FUNC_END(preempt_vmx) diff --git a/tools/testing/selftests/powerpc/math/vmx_preempt.c b/tools/testing/selftests/powerpc/math/vmx_preempt.c new file mode 100644 index 000000000000..9ef376c55b13 --- /dev/null +++ b/tools/testing/selftests/powerpc/math/vmx_preempt.c @@ -0,0 +1,112 @@ +/* + * Copyright 2015, Cyril Bur, IBM Corp. + * + * 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. + * + * This test attempts to see if the VMX registers change across preemption. + * Two things should be noted here a) The check_vmx function in asm only checks + * the non volatile registers as it is reused from the syscall test b) There is + * no way to be sure preemption happened so this test just uses many threads + * and a long wait. As such, a successful test doesn't mean much but a failure + * is bad. + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#include "utils.h" + +/* Time to wait for workers to get preempted (seconds) */ +#define PREEMPT_TIME 20 +/* + * Factor by which to multiply number of online CPUs for total number of + * worker threads + */ +#define THREAD_FACTOR 8 + +__thread vector int varray[] = {{1, 2, 3, 4}, {5, 6, 7, 8}, {9, 10,11,12}, + {13,14,15,16},{17,18,19,20},{21,22,23,24}, + {25,26,27,28},{29,30,31,32},{33,34,35,36}, + {37,38,39,40},{41,42,43,44},{45,46,47,48}}; + +int threads_starting; +int running; + +extern void preempt_vmx(vector int *varray, int *threads_starting, int *running); + +void *preempt_vmx_c(void *p) +{ + int i, j; + srand(pthread_self()); + for (i = 0; i < 12; i++) + for (j = 0; j < 4; j++) + varray[i][j] = rand(); + + /* Test fails if it ever returns */ + preempt_vmx(varray, &threads_starting, &running); + return p; +} + +int test_preempt_vmx(void) +{ + int i, rc, threads; + pthread_t *tids; + + threads = sysconf(_SC_NPROCESSORS_ONLN) * THREAD_FACTOR; + tids = malloc(threads * sizeof(pthread_t)); + FAIL_IF(!tids); + + running = true; + threads_starting = threads; + for (i = 0; i < threads; i++) { + rc = pthread_create(&tids[i], NULL, preempt_vmx_c, NULL); + FAIL_IF(rc); + } + + setbuf(stdout, NULL); + /* Not really nessesary but nice to wait for every thread to start */ + printf("\tWaiting for all workers to start..."); + while(threads_starting) + asm volatile("": : :"memory"); + printf("done\n"); + + printf("\tWaiting for %d seconds to let some workers get preempted...", PREEMPT_TIME); + sleep(PREEMPT_TIME); + printf("done\n"); + + printf("\tStopping workers..."); + /* + * Working are checking this value every loop. In preempt_vmx 'cmpwi r5,0; bne 2b'. + * r5 will have loaded the value of running. + */ + running = 0; + for (i = 0; i < threads; i++) { + void *rc_p; + pthread_join(tids[i], &rc_p); + + /* + * Harness will say the fail was here, look at why preempt_vmx + * returned + */ + if ((long) rc_p) + printf("oops\n"); + FAIL_IF((long) rc_p); + } + printf("done\n"); + + return 0; +} + +int main(int argc, char *argv[]) +{ + return test_harness(test_preempt_vmx, "vmx_preempt"); +}