diff options
Diffstat (limited to 'kernel/tools/testing/selftests/powerpc/tm')
5 files changed, 261 insertions, 0 deletions
diff --git a/kernel/tools/testing/selftests/powerpc/tm/.gitignore b/kernel/tools/testing/selftests/powerpc/tm/.gitignore new file mode 100644 index 000000000..2699635d2 --- /dev/null +++ b/kernel/tools/testing/selftests/powerpc/tm/.gitignore @@ -0,0 +1,2 @@ +tm-resched-dscr +tm-syscall diff --git a/kernel/tools/testing/selftests/powerpc/tm/Makefile b/kernel/tools/testing/selftests/powerpc/tm/Makefile new file mode 100644 index 000000000..6bff955e1 --- /dev/null +++ b/kernel/tools/testing/selftests/powerpc/tm/Makefile @@ -0,0 +1,13 @@ +TEST_PROGS := tm-resched-dscr + +all: $(TEST_PROGS) + +$(TEST_PROGS): ../harness.c + +tm-syscall: tm-syscall-asm.S +tm-syscall: CFLAGS += -mhtm + +include ../../lib.mk + +clean: + rm -f $(TEST_PROGS) *.o diff --git a/kernel/tools/testing/selftests/powerpc/tm/tm-resched-dscr.c b/kernel/tools/testing/selftests/powerpc/tm/tm-resched-dscr.c new file mode 100644 index 000000000..42d4c8caa --- /dev/null +++ b/kernel/tools/testing/selftests/powerpc/tm/tm-resched-dscr.c @@ -0,0 +1,98 @@ +/* Test context switching to see if the DSCR SPR is correctly preserved + * when within a transaction. + * + * Note: We assume that the DSCR has been left at the default value (0) + * for all CPUs. + * + * Method: + * + * Set a value into the DSCR. + * + * Start a transaction, and suspend it (*). + * + * Hard loop checking to see if the transaction has become doomed. + * + * Now that we *may* have been preempted, record the DSCR and TEXASR SPRS. + * + * If the abort was because of a context switch, check the DSCR value. + * Otherwise, try again. + * + * (*) If the transaction is not suspended we can't see the problem because + * the transaction abort handler will restore the DSCR to it's checkpointed + * value before we regain control. + */ + +#include <inttypes.h> +#include <stdio.h> +#include <stdlib.h> +#include <assert.h> +#include <asm/tm.h> + +#include "utils.h" + +#define TBEGIN ".long 0x7C00051D ;" +#define TEND ".long 0x7C00055D ;" +#define TCHECK ".long 0x7C00059C ;" +#define TSUSPEND ".long 0x7C0005DD ;" +#define TRESUME ".long 0x7C2005DD ;" +#define SPRN_TEXASR 0x82 +#define SPRN_DSCR 0x03 + +int test_body(void) +{ + uint64_t rv, dscr1 = 1, dscr2, texasr; + + printf("Check DSCR TM context switch: "); + fflush(stdout); + for (;;) { + rv = 1; + asm __volatile__ ( + /* set a known value into the DSCR */ + "ld 3, %[dscr1];" + "mtspr %[sprn_dscr], 3;" + + /* start and suspend a transaction */ + TBEGIN + "beq 1f;" + TSUSPEND + + /* hard loop until the transaction becomes doomed */ + "2: ;" + TCHECK + "bc 4, 0, 2b;" + + /* record DSCR and TEXASR */ + "mfspr 3, %[sprn_dscr];" + "std 3, %[dscr2];" + "mfspr 3, %[sprn_texasr];" + "std 3, %[texasr];" + + TRESUME + TEND + "li %[rv], 0;" + "1: ;" + : [rv]"=r"(rv), [dscr2]"=m"(dscr2), [texasr]"=m"(texasr) + : [dscr1]"m"(dscr1) + , [sprn_dscr]"i"(SPRN_DSCR), [sprn_texasr]"i"(SPRN_TEXASR) + : "memory", "r3" + ); + assert(rv); /* make sure the transaction aborted */ + if ((texasr >> 56) != TM_CAUSE_RESCHED) { + putchar('.'); + fflush(stdout); + continue; + } + if (dscr2 != dscr1) { + printf(" FAIL\n"); + return 1; + } else { + printf(" OK\n"); + return 0; + } + } +} + +int main(void) +{ + return test_harness(test_body, "tm_resched_dscr"); +} diff --git a/kernel/tools/testing/selftests/powerpc/tm/tm-syscall-asm.S b/kernel/tools/testing/selftests/powerpc/tm/tm-syscall-asm.S new file mode 100644 index 000000000..431f61ae2 --- /dev/null +++ b/kernel/tools/testing/selftests/powerpc/tm/tm-syscall-asm.S @@ -0,0 +1,27 @@ +#include <ppc-asm.h> +#include <asm/unistd.h> + + .text +FUNC_START(getppid_tm_active) + tbegin. + beq 1f + li r0, __NR_getppid + sc + tend. + blr +1: + li r3, -1 + blr + +FUNC_START(getppid_tm_suspended) + tbegin. + beq 1f + li r0, __NR_getppid + tsuspend. + sc + tresume. + tend. + blr +1: + li r3, -1 + blr diff --git a/kernel/tools/testing/selftests/powerpc/tm/tm-syscall.c b/kernel/tools/testing/selftests/powerpc/tm/tm-syscall.c new file mode 100644 index 000000000..3ed8d4b25 --- /dev/null +++ b/kernel/tools/testing/selftests/powerpc/tm/tm-syscall.c @@ -0,0 +1,121 @@ +/* + * Copyright 2015, Sam Bobroff, IBM Corp. + * Licensed under GPLv2. + * + * Test the kernel's system call code to ensure that a system call + * made from within an active HTM transaction is aborted with the + * correct failure code. + * Conversely, ensure that a system call made from within a + * suspended transaction can succeed. + */ + +#include <stdio.h> +#include <unistd.h> +#include <sys/syscall.h> +#include <asm/tm.h> +#include <asm/cputable.h> +#include <linux/auxvec.h> +#include <sys/time.h> +#include <stdlib.h> + +#include "utils.h" + +extern int getppid_tm_active(void); +extern int getppid_tm_suspended(void); + +unsigned retries = 0; + +#define TEST_DURATION 10 /* seconds */ +#define TM_RETRIES 100 + +long failure_code(void) +{ + return __builtin_get_texasru() >> 24; +} + +bool failure_is_persistent(void) +{ + return (failure_code() & TM_CAUSE_PERSISTENT) == TM_CAUSE_PERSISTENT; +} + +bool failure_is_syscall(void) +{ + return (failure_code() & TM_CAUSE_SYSCALL) == TM_CAUSE_SYSCALL; +} + +pid_t getppid_tm(bool suspend) +{ + int i; + pid_t pid; + + for (i = 0; i < TM_RETRIES; i++) { + if (suspend) + pid = getppid_tm_suspended(); + else + pid = getppid_tm_active(); + + if (pid >= 0) + return pid; + + if (failure_is_persistent()) { + if (failure_is_syscall()) + return -1; + + printf("Unexpected persistent transaction failure.\n"); + printf("TEXASR 0x%016lx, TFIAR 0x%016lx.\n", + __builtin_get_texasr(), __builtin_get_tfiar()); + exit(-1); + } + + retries++; + } + + printf("Exceeded limit of %d temporary transaction failures.\n", TM_RETRIES); + printf("TEXASR 0x%016lx, TFIAR 0x%016lx.\n", + __builtin_get_texasr(), __builtin_get_tfiar()); + + exit(-1); +} + +int tm_syscall(void) +{ + unsigned count = 0; + struct timeval end, now; + + SKIP_IF(!((long)get_auxv_entry(AT_HWCAP2) & PPC_FEATURE2_HTM)); + setbuf(stdout, NULL); + + printf("Testing transactional syscalls for %d seconds...\n", TEST_DURATION); + + gettimeofday(&end, NULL); + now.tv_sec = TEST_DURATION; + now.tv_usec = 0; + timeradd(&end, &now, &end); + + for (count = 0; timercmp(&now, &end, <); count++) { + /* + * Test a syscall within a suspended transaction and verify + * that it succeeds. + */ + FAIL_IF(getppid_tm(true) == -1); /* Should succeed. */ + + /* + * Test a syscall within an active transaction and verify that + * it fails with the correct failure code. + */ + FAIL_IF(getppid_tm(false) != -1); /* Should fail... */ + FAIL_IF(!failure_is_persistent()); /* ...persistently... */ + FAIL_IF(!failure_is_syscall()); /* ...with code syscall. */ + gettimeofday(&now, 0); + } + + printf("%d active and suspended transactions behaved correctly.\n", count); + printf("(There were %d transaction retries.)\n", retries); + + return 0; +} + +int main(void) +{ + return test_harness(tm_syscall, "tm_syscall"); +} |