From 86a8938078a8bb518c5376de493e348c7490d506 Mon Sep 17 00:00:00 2001 From: Luca Barbieri Date: Wed, 24 Feb 2010 10:54:24 +0100 Subject: lib: Add self-test for atomic64_t This patch adds self-test on boot code for atomic64_t. This has been used to test the later changes in this patchset. Signed-off-by: Luca Barbieri LKML-Reference: <1267005265-27958-4-git-send-email-luca@luca-barbieri.com> Signed-off-by: H. Peter Anvin --- lib/Kconfig.debug | 7 +++ lib/Makefile | 2 + lib/atomic64_test.c | 158 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 167 insertions(+) create mode 100644 lib/atomic64_test.c (limited to 'lib') diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 25c3ed594c54..3676c517a073 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1054,6 +1054,13 @@ config DMA_API_DEBUG This option causes a performance degredation. Use only if you want to debug device drivers. If unsure, say N. +config ATOMIC64_SELFTEST + bool "Perform an atomic64_t self-test at boot" + help + Enable this option to test the atomic64_t functions at boot. + + If unsure, say N. + source "samples/Kconfig" source "lib/Kconfig.kgdb" diff --git a/lib/Makefile b/lib/Makefile index 347ad8db29d3..4af4786fe281 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -99,6 +99,8 @@ obj-$(CONFIG_GENERIC_CSUM) += checksum.o obj-$(CONFIG_GENERIC_ATOMIC64) += atomic64.o +obj-$(CONFIG_ATOMIC64_SELFTEST) += atomic64_test.o + hostprogs-y := gen_crc32table clean-files := crc32table.h diff --git a/lib/atomic64_test.c b/lib/atomic64_test.c new file mode 100644 index 000000000000..4ff649e46bad --- /dev/null +++ b/lib/atomic64_test.c @@ -0,0 +1,158 @@ +/* + * Testsuite for atomic64_t functions + * + * Copyright © 2010 Luca Barbieri + * + * 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 +#include + +#define INIT(c) do { atomic64_set(&v, c); r = c; } while (0) +static __init int test_atomic64(void) +{ + long long v0 = 0xaaa31337c001d00dLL; + long long v1 = 0xdeadbeefdeafcafeLL; + long long v2 = 0xfaceabadf00df001LL; + long long onestwos = 0x1111111122222222LL; + long long one = 1LL; + + atomic64_t v = ATOMIC64_INIT(v0); + long long r = v0; + BUG_ON(v.counter != r); + + atomic64_set(&v, v1); + r = v1; + BUG_ON(v.counter != r); + BUG_ON(atomic64_read(&v) != r); + + INIT(v0); + atomic64_add(onestwos, &v); + r += onestwos; + BUG_ON(v.counter != r); + + INIT(v0); + atomic64_add(-one, &v); + r += -one; + BUG_ON(v.counter != r); + + INIT(v0); + r += onestwos; + BUG_ON(atomic64_add_return(onestwos, &v) != r); + BUG_ON(v.counter != r); + + INIT(v0); + r += -one; + BUG_ON(atomic64_add_return(-one, &v) != r); + BUG_ON(v.counter != r); + + INIT(v0); + atomic64_sub(onestwos, &v); + r -= onestwos; + BUG_ON(v.counter != r); + + INIT(v0); + atomic64_sub(-one, &v); + r -= -one; + BUG_ON(v.counter != r); + + INIT(v0); + r -= onestwos; + BUG_ON(atomic64_sub_return(onestwos, &v) != r); + BUG_ON(v.counter != r); + + INIT(v0); + r -= -one; + BUG_ON(atomic64_sub_return(-one, &v) != r); + BUG_ON(v.counter != r); + + INIT(v0); + atomic64_inc(&v); + r += one; + BUG_ON(v.counter != r); + + INIT(v0); + r += one; + BUG_ON(atomic64_inc_return(&v) != r); + BUG_ON(v.counter != r); + + INIT(v0); + atomic64_dec(&v); + r -= one; + BUG_ON(v.counter != r); + + INIT(v0); + r -= one; + BUG_ON(atomic64_dec_return(&v) != r); + BUG_ON(v.counter != r); + + INIT(v0); + BUG_ON(atomic64_xchg(&v, v1) != v0); + r = v1; + BUG_ON(v.counter != r); + + INIT(v0); + BUG_ON(atomic64_cmpxchg(&v, v0, v1) != v0); + r = v1; + BUG_ON(v.counter != r); + + INIT(v0); + BUG_ON(atomic64_cmpxchg(&v, v2, v1) != v0); + BUG_ON(v.counter != r); + + INIT(v0); + BUG_ON(!atomic64_add_unless(&v, one, v0)); + BUG_ON(v.counter != r); + + INIT(v0); + BUG_ON(atomic64_add_unless(&v, one, v1)); + r += one; + BUG_ON(v.counter != r); + + INIT(onestwos); + BUG_ON(atomic64_dec_if_positive(&v) != (onestwos - 1)); + r -= one; + BUG_ON(v.counter != r); + + INIT(0); + BUG_ON(atomic64_dec_if_positive(&v) != -one); + BUG_ON(v.counter != r); + + INIT(-one); + BUG_ON(atomic64_dec_if_positive(&v) != (-one - one)); + BUG_ON(v.counter != r); + + INIT(onestwos); + BUG_ON(atomic64_inc_not_zero(&v)); + r += one; + BUG_ON(v.counter != r); + + INIT(0); + BUG_ON(!atomic64_inc_not_zero(&v)); + BUG_ON(v.counter != r); + + INIT(-one); + BUG_ON(atomic64_inc_not_zero(&v)); + r += one; + BUG_ON(v.counter != r); + +#ifdef CONFIG_X86 + printk(KERN_INFO "atomic64 test passed for %s+ platform %s CX8 and %s SSE\n", +#ifdef CONFIG_X86_CMPXCHG64 + "586", +#else + "386", +#endif + boot_cpu_has(X86_FEATURE_CX8) ? "with" : "without", + boot_cpu_has(X86_FEATURE_XMM) ? "with" : "without"); +#else + printk(KERN_INFO "atomic64 test passed\n"); +#endif + + return 0; +} + +core_initcall(test_atomic64); -- cgit v1.2.3 From 8f4f202b335144bf5be5c9e5b1bc9477ecdae958 Mon Sep 17 00:00:00 2001 From: Luca Barbieri Date: Fri, 26 Feb 2010 12:22:40 +0100 Subject: lib: Only test atomic64_dec_if_positive on archs having it Currently atomic64_dec_if_positive() is only supported by PowerPC, MIPS and x86-32. Signed-off-by: Luca Barbieri LKML-Reference: <1267183361-20775-1-git-send-email-luca@luca-barbieri.com> Signed-off-by: H. Peter Anvin --- lib/atomic64_test.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'lib') diff --git a/lib/atomic64_test.c b/lib/atomic64_test.c index 4ff649e46bad..0effcacbebda 100644 --- a/lib/atomic64_test.c +++ b/lib/atomic64_test.c @@ -112,6 +112,7 @@ static __init int test_atomic64(void) r += one; BUG_ON(v.counter != r); +#if defined(CONFIG_X86_32) || defined(CONFIG_MIPS) || defined(CONFIG_PPC) || defined(_ASM_GENERIC_ATOMIC64_H) INIT(onestwos); BUG_ON(atomic64_dec_if_positive(&v) != (onestwos - 1)); r -= one; @@ -124,6 +125,9 @@ static __init int test_atomic64(void) INIT(-one); BUG_ON(atomic64_dec_if_positive(&v) != (-one - one)); BUG_ON(v.counter != r); +#else +#warning Please implement atomic64_dec_if_positive for your architecture, and add it to the IF above +#endif INIT(onestwos); BUG_ON(atomic64_inc_not_zero(&v)); -- cgit v1.2.3 From d7f6de1e9c4a12e11ba7186c70f0f40caa76f590 Mon Sep 17 00:00:00 2001 From: Luca Barbieri Date: Fri, 26 Feb 2010 12:22:41 +0100 Subject: x86: Implement atomic[64]_dec_if_positive() Add support for atomic_dec_if_positive(), and atomic64_dec_if_positive() for x86-64. atomic64_dec_if_positive() for x86-32 was already implemented in a previous patch. Signed-off-by: Luca Barbieri LKML-Reference: <1267183361-20775-2-git-send-email-luca@luca-barbieri.com> Signed-off-by: H. Peter Anvin --- arch/x86/include/asm/atomic.h | 23 +++++++++++++++++++++++ arch/x86/include/asm/atomic64_64.h | 23 +++++++++++++++++++++++ lib/atomic64_test.c | 2 +- 3 files changed, 47 insertions(+), 1 deletion(-) (limited to 'lib') diff --git a/arch/x86/include/asm/atomic.h b/arch/x86/include/asm/atomic.h index 8f8217b9bdac..706c69492c14 100644 --- a/arch/x86/include/asm/atomic.h +++ b/arch/x86/include/asm/atomic.h @@ -246,6 +246,29 @@ static inline int atomic_add_unless(atomic_t *v, int a, int u) #define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) +/* + * atomic_dec_if_positive - decrement by 1 if old value positive + * @v: pointer of type atomic_t + * + * The function returns the old value of *v minus 1, even if + * the atomic variable, v, was not decremented. + */ +static inline int atomic_dec_if_positive(atomic_t *v) +{ + int c, old, dec; + c = atomic_read(v); + for (;;) { + dec = c - 1; + if (unlikely(dec < 0)) + break; + old = atomic_cmpxchg((v), c, dec); + if (likely(old == c)) + break; + c = old; + } + return dec; +} + /** * atomic_inc_short - increment of a short integer * @v: pointer to type int diff --git a/arch/x86/include/asm/atomic64_64.h b/arch/x86/include/asm/atomic64_64.h index 51c5b4056929..4d6e2cd6c88c 100644 --- a/arch/x86/include/asm/atomic64_64.h +++ b/arch/x86/include/asm/atomic64_64.h @@ -221,4 +221,27 @@ static inline int atomic64_add_unless(atomic64_t *v, long a, long u) #define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0) +/* + * atomic64_dec_if_positive - decrement by 1 if old value positive + * @v: pointer of type atomic_t + * + * The function returns the old value of *v minus 1, even if + * the atomic variable, v, was not decremented. + */ +static inline long atomic64_dec_if_positive(atomic64_t *v) +{ + long c, old, dec; + c = atomic64_read(v); + for (;;) { + dec = c - 1; + if (unlikely(dec < 0)) + break; + old = atomic64_cmpxchg((v), c, dec); + if (likely(old == c)) + break; + c = old; + } + return dec; +} + #endif /* _ASM_X86_ATOMIC64_64_H */ diff --git a/lib/atomic64_test.c b/lib/atomic64_test.c index 0effcacbebda..58efdabb3845 100644 --- a/lib/atomic64_test.c +++ b/lib/atomic64_test.c @@ -112,7 +112,7 @@ static __init int test_atomic64(void) r += one; BUG_ON(v.counter != r); -#if defined(CONFIG_X86_32) || defined(CONFIG_MIPS) || defined(CONFIG_PPC) || defined(_ASM_GENERIC_ATOMIC64_H) +#if defined(CONFIG_X86) || defined(CONFIG_MIPS) || defined(CONFIG_PPC) || defined(_ASM_GENERIC_ATOMIC64_H) INIT(onestwos); BUG_ON(atomic64_dec_if_positive(&v) != (onestwos - 1)); r -= one; -- cgit v1.2.3 From 9efbcd590243045111670c171a951923b877b57d Mon Sep 17 00:00:00 2001 From: Luca Barbieri Date: Mon, 1 Mar 2010 19:55:45 +0100 Subject: lib: Fix atomic64_add_unless test atomic64_add_unless must return 1 if it perfomed the add and 0 otherwise. The test assumed the opposite convention. Reported-by: H. Peter Anvin Signed-off-by: Luca Barbieri LKML-Reference: <1267469749-11878-2-git-send-email-luca@luca-barbieri.com> Signed-off-by: H. Peter Anvin --- lib/atomic64_test.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'lib') diff --git a/lib/atomic64_test.c b/lib/atomic64_test.c index 58efdabb3845..ee8e6de8b413 100644 --- a/lib/atomic64_test.c +++ b/lib/atomic64_test.c @@ -104,11 +104,11 @@ static __init int test_atomic64(void) BUG_ON(v.counter != r); INIT(v0); - BUG_ON(!atomic64_add_unless(&v, one, v0)); + BUG_ON(atomic64_add_unless(&v, one, v0)); BUG_ON(v.counter != r); INIT(v0); - BUG_ON(atomic64_add_unless(&v, one, v1)); + BUG_ON(!atomic64_add_unless(&v, one, v1)); r += one; BUG_ON(v.counter != r); -- cgit v1.2.3 From 97577896f6b9c056fa0a5e9f6a608110cb3dcd33 Mon Sep 17 00:00:00 2001 From: Luca Barbieri Date: Mon, 1 Mar 2010 19:55:47 +0100 Subject: lib: Fix atomic64_add_unless return value convention atomic64_add_unless must return 1 if it perfomed the add and 0 otherwise. The generic implementation did the opposite thing. Reported-by: H. Peter Anvin Confirmed-by: Paul Mackerras Signed-off-by: Luca Barbieri LKML-Reference: <1267469749-11878-4-git-send-email-luca@luca-barbieri.com> Signed-off-by: H. Peter Anvin --- lib/atomic64.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'lib') diff --git a/lib/atomic64.c b/lib/atomic64.c index 8bee16ec7524..a21c12bc727c 100644 --- a/lib/atomic64.c +++ b/lib/atomic64.c @@ -162,12 +162,12 @@ int atomic64_add_unless(atomic64_t *v, long long a, long long u) { unsigned long flags; spinlock_t *lock = lock_addr(v); - int ret = 1; + int ret = 0; spin_lock_irqsave(lock, flags); if (v->counter != u) { v->counter += a; - ret = 0; + ret = 1; } spin_unlock_irqrestore(lock, flags); return ret; -- cgit v1.2.3 From 25a304f277ad70166eeae25a4958d2049005c33a Mon Sep 17 00:00:00 2001 From: Luca Barbieri Date: Mon, 1 Mar 2010 19:55:48 +0100 Subject: lib: Fix atomic64_inc_not_zero test atomic64_inc_not_zero must return 1 if it perfomed the add and 0 otherwise. The test assumed the opposite convention. Signed-off-by: Luca Barbieri LKML-Reference: <1267469749-11878-5-git-send-email-luca@luca-barbieri.com> Signed-off-by: H. Peter Anvin --- lib/atomic64_test.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'lib') diff --git a/lib/atomic64_test.c b/lib/atomic64_test.c index ee8e6de8b413..f7bb706c9c3a 100644 --- a/lib/atomic64_test.c +++ b/lib/atomic64_test.c @@ -130,16 +130,16 @@ static __init int test_atomic64(void) #endif INIT(onestwos); - BUG_ON(atomic64_inc_not_zero(&v)); + BUG_ON(!atomic64_inc_not_zero(&v)); r += one; BUG_ON(v.counter != r); INIT(0); - BUG_ON(!atomic64_inc_not_zero(&v)); + BUG_ON(atomic64_inc_not_zero(&v)); BUG_ON(v.counter != r); INIT(-one); - BUG_ON(atomic64_inc_not_zero(&v)); + BUG_ON(!atomic64_inc_not_zero(&v)); r += one; BUG_ON(v.counter != r); -- cgit v1.2.3 From a5c9161f27c3e1ae6c0094d262f03a7e98262181 Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Mon, 1 Mar 2010 11:49:23 -0800 Subject: x86, atomic64: In selftest, distinguish x86-64 from 586+ The x86-64 implementation of the atomics is totally different from the i586+ implementation, which makes it quite confusing to call it "586+". Also fix indentation, and add "i" for "i386" and "i586" as used elsewhere in the kernel. Signed-off-by: H. Peter Anvin Cc: Luca Barbieri LKML-Reference: <1267005265-27958-4-git-send-email-luca@luca-barbieri.com> --- lib/atomic64_test.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) (limited to 'lib') diff --git a/lib/atomic64_test.c b/lib/atomic64_test.c index f7bb706c9c3a..65e482caf5e9 100644 --- a/lib/atomic64_test.c +++ b/lib/atomic64_test.c @@ -144,14 +144,16 @@ static __init int test_atomic64(void) BUG_ON(v.counter != r); #ifdef CONFIG_X86 - printk(KERN_INFO "atomic64 test passed for %s+ platform %s CX8 and %s SSE\n", -#ifdef CONFIG_X86_CMPXCHG64 - "586", + printk(KERN_INFO "atomic64 test passed for %s platform %s CX8 and %s SSE\n", +#ifdef CONFIG_X86_64 + "x86-64", +#elif defined(CONFIG_X86_CMPXCHG64) + "i586+", #else - "386", + "i386+", #endif - boot_cpu_has(X86_FEATURE_CX8) ? "with" : "without", - boot_cpu_has(X86_FEATURE_XMM) ? "with" : "without"); + boot_cpu_has(X86_FEATURE_CX8) ? "with" : "without", + boot_cpu_has(X86_FEATURE_XMM) ? "with" : "without"); #else printk(KERN_INFO "atomic64 test passed\n"); #endif -- cgit v1.2.3