From: Glauber Costa <glommer@redhat.com> Date: Mon, 24 May 2010 20:08:05 -0400 Subject: [x86] grab atomic64 types from upstream Message-id: <1274731689-21363-2-git-send-email-glommer@redhat.com> Patchwork-id: 25794 O-Subject: [PATCH RHEL5.6/5.5.z v2 1/5] grab atomic64 types from upstream Bugzilla: 570824 RH-Acked-by: Rik van Riel <riel@redhat.com> RH-Acked-by: Zachary Amsden <zamsden@redhat.com> RH-Acked-by: Jes Sorensen <Jes.Sorensen@redhat.com> RH-Author: Glauber Costa <glommer@redhat.com> RH-Bugzilla: 570824 and many, many others RH-Upstream-status: N/A Our kernel lacks support for atomic 64 bit operations in 32-bit platforms. This patch is a verbatim copy of the related files from upstream kernels Signed-off-by: Glauber Costa <glommer@redhat.com> [ v2: don't make atomic64 include global. breaks rds.ko ] diff --git a/arch/i386/kernel/pvclock.c b/arch/i386/kernel/pvclock.c index 3b08ff5..94280dd 100644 --- a/arch/i386/kernel/pvclock.c +++ b/arch/i386/kernel/pvclock.c @@ -19,6 +19,10 @@ #include <linux/percpu.h> #include <asm/pvclock.h> +#ifdef CONFIG_X86_32 +#include <asm/atomic64_32.h> +#endif + /* * These are perodically updated * xen: magic shared_info page diff --git a/arch/i386/lib/Makefile b/arch/i386/lib/Makefile index 920f0af..c6e74e1 100644 --- a/arch/i386/lib/Makefile +++ b/arch/i386/lib/Makefile @@ -4,7 +4,7 @@ lib-y = checksum.o delay.o usercopy.o getuser.o putuser.o memcpy.o strstr.o \ - bitops.o + bitops.o atomic64_32.o lib-$(CONFIG_X86_USE_3DNOW) += mmx.o diff --git a/arch/i386/lib/atomic64_32.c b/arch/i386/lib/atomic64_32.c new file mode 100644 index 0000000..e226c27 --- /dev/null +++ b/arch/i386/lib/atomic64_32.c @@ -0,0 +1,230 @@ +#include <linux/compiler.h> +#include <linux/module.h> +#include <linux/types.h> + +#include <asm/processor.h> +#include <asm/atomic.h> +#include <asm/atomic64_32.h> + +static noinline u64 cmpxchg8b(u64 *ptr, u64 old, u64 new) +{ + u32 low = new; + u32 high = new >> 32; + + asm volatile( + LOCK_PREFIX "cmpxchg8b %1\n" + : "+A" (old), "+m" (*ptr) + : "b" (low), "c" (high) + ); + return old; +} + +u64 atomic64_cmpxchg(atomic64_t *ptr, u64 old_val, u64 new_val) +{ + return cmpxchg8b(&ptr->counter, old_val, new_val); +} +EXPORT_SYMBOL(atomic64_cmpxchg); + +/** + * atomic64_xchg - xchg atomic64 variable + * @ptr: pointer to type atomic64_t + * @new_val: value to assign + * + * Atomically xchgs the value of @ptr to @new_val and returns + * the old value. + */ +u64 atomic64_xchg(atomic64_t *ptr, u64 new_val) +{ + /* + * Try first with a (possibly incorrect) assumption about + * what we have there. We'll do two loops most likely, + * but we'll get an ownership MESI transaction straight away + * instead of a read transaction followed by a + * flush-for-ownership transaction: + */ + u64 old_val, real_val = 0; + + do { + old_val = real_val; + + real_val = atomic64_cmpxchg(ptr, old_val, new_val); + + } while (real_val != old_val); + + return old_val; +} +EXPORT_SYMBOL(atomic64_xchg); + +/** + * atomic64_set - set atomic64 variable + * @ptr: pointer to type atomic64_t + * @new_val: value to assign + * + * Atomically sets the value of @ptr to @new_val. + */ +void atomic64_set(atomic64_t *ptr, u64 new_val) +{ + atomic64_xchg(ptr, new_val); +} +EXPORT_SYMBOL(atomic64_set); + +/** +EXPORT_SYMBOL(atomic64_read); + * atomic64_add_return - add and return + * @delta: integer value to add + * @ptr: pointer to type atomic64_t + * + * Atomically adds @delta to @ptr and returns @delta + *@ptr + */ +noinline u64 atomic64_add_return(u64 delta, atomic64_t *ptr) +{ + /* + * Try first with a (possibly incorrect) assumption about + * what we have there. We'll do two loops most likely, + * but we'll get an ownership MESI transaction straight away + * instead of a read transaction followed by a + * flush-for-ownership transaction: + */ + u64 old_val, new_val, real_val = 0; + + do { + old_val = real_val; + new_val = old_val + delta; + + real_val = atomic64_cmpxchg(ptr, old_val, new_val); + + } while (real_val != old_val); + + return new_val; +} +EXPORT_SYMBOL(atomic64_add_return); + +u64 atomic64_sub_return(u64 delta, atomic64_t *ptr) +{ + return atomic64_add_return(-delta, ptr); +} +EXPORT_SYMBOL(atomic64_sub_return); + +u64 atomic64_inc_return(atomic64_t *ptr) +{ + return atomic64_add_return(1, ptr); +} +EXPORT_SYMBOL(atomic64_inc_return); + +u64 atomic64_dec_return(atomic64_t *ptr) +{ + return atomic64_sub_return(1, ptr); +} +EXPORT_SYMBOL(atomic64_dec_return); + +/** + * atomic64_add - add integer to atomic64 variable + * @delta: integer value to add + * @ptr: pointer to type atomic64_t + * + * Atomically adds @delta to @ptr. + */ +void atomic64_add(u64 delta, atomic64_t *ptr) +{ + atomic64_add_return(delta, ptr); +} +EXPORT_SYMBOL(atomic64_add); + +/** + * atomic64_sub - subtract the atomic64 variable + * @delta: integer value to subtract + * @ptr: pointer to type atomic64_t + * + * Atomically subtracts @delta from @ptr. + */ +void atomic64_sub(u64 delta, atomic64_t *ptr) +{ + atomic64_add(-delta, ptr); +} +EXPORT_SYMBOL(atomic64_sub); + +/** + * atomic64_sub_and_test - subtract value from variable and test result + * @delta: integer value to subtract + * @ptr: pointer to type atomic64_t + * + * Atomically subtracts @delta from @ptr and returns + * true if the result is zero, or false for all + * other cases. + */ +int atomic64_sub_and_test(u64 delta, atomic64_t *ptr) +{ + u64 new_val = atomic64_sub_return(delta, ptr); + + return new_val == 0; +} +EXPORT_SYMBOL(atomic64_sub_and_test); + +/** + * atomic64_inc - increment atomic64 variable + * @ptr: pointer to type atomic64_t + * + * Atomically increments @ptr by 1. + */ +void atomic64_inc(atomic64_t *ptr) +{ + atomic64_add(1, ptr); +} +EXPORT_SYMBOL(atomic64_inc); + +/** + * atomic64_dec - decrement atomic64 variable + * @ptr: pointer to type atomic64_t + * + * Atomically decrements @ptr by 1. + */ +void atomic64_dec(atomic64_t *ptr) +{ + atomic64_sub(1, ptr); +} +EXPORT_SYMBOL(atomic64_dec); + +/** + * atomic64_dec_and_test - decrement and test + * @ptr: pointer to type atomic64_t + * + * Atomically decrements @ptr by 1 and + * returns true if the result is 0, or false for all other + * cases. + */ +int atomic64_dec_and_test(atomic64_t *ptr) +{ + return atomic64_sub_and_test(1, ptr); +} +EXPORT_SYMBOL(atomic64_dec_and_test); + +/** + * atomic64_inc_and_test - increment and test + * @ptr: pointer to type atomic64_t + * + * Atomically increments @ptr by 1 + * and returns true if the result is zero, or false for all + * other cases. + */ +int atomic64_inc_and_test(atomic64_t *ptr) +{ + return atomic64_sub_and_test(-1, ptr); +} +EXPORT_SYMBOL(atomic64_inc_and_test); + +/** + * atomic64_add_negative - add and test if negative + * @delta: integer value to add + * @ptr: pointer to type atomic64_t + * + * Atomically adds @delta to @ptr and returns true + * if the result is negative, or false when + * result is greater than or equal to zero. + */ +int atomic64_add_negative(u64 delta, atomic64_t *ptr) +{ + s64 new_val = atomic64_add_return(delta, ptr); + + return new_val < 0; +} +EXPORT_SYMBOL(atomic64_add_negative); diff --git a/include/asm-i386/atomic64_32.h b/include/asm-i386/atomic64_32.h new file mode 100644 index 0000000..03027bf --- /dev/null +++ b/include/asm-i386/atomic64_32.h @@ -0,0 +1,160 @@ +#ifndef _ASM_X86_ATOMIC64_32_H +#define _ASM_X86_ATOMIC64_32_H + +#include <linux/compiler.h> +#include <linux/types.h> +#include <asm/processor.h> +//#include <asm/cmpxchg.h> + +/* An 64bit atomic type */ + +typedef struct { + u64 __aligned(8) counter; +} atomic64_t; + +#define ATOMIC64_INIT(val) { (val) } + +extern u64 atomic64_cmpxchg(atomic64_t *ptr, u64 old_val, u64 new_val); + +/** + * atomic64_xchg - xchg atomic64 variable + * @ptr: pointer to type atomic64_t + * @new_val: value to assign + * + * Atomically xchgs the value of @ptr to @new_val and returns + * the old value. + */ +extern u64 atomic64_xchg(atomic64_t *ptr, u64 new_val); + +/** + * atomic64_set - set atomic64 variable + * @ptr: pointer to type atomic64_t + * @new_val: value to assign + * + * Atomically sets the value of @ptr to @new_val. + */ +extern void atomic64_set(atomic64_t *ptr, u64 new_val); + +/** + * atomic64_read - read atomic64 variable + * @ptr: pointer to type atomic64_t + * + * Atomically reads the value of @ptr and returns it. + */ +static inline u64 atomic64_read(atomic64_t *ptr) +{ + u64 res; + + /* + * Note, we inline this atomic64_t primitive because + * it only clobbers EAX/EDX and leaves the others + * untouched. We also (somewhat subtly) rely on the + * fact that cmpxchg8b returns the current 64-bit value + * of the memory location we are touching: + */ + asm volatile( + "mov %%ebx, %%eax\n\t" + "mov %%ecx, %%edx\n\t" + LOCK_PREFIX "cmpxchg8b %1\n" + : "=&A" (res) + : "m" (*ptr) + ); + + return res; +} + +extern u64 atomic64_read(atomic64_t *ptr); + +/** + * atomic64_add_return - add and return + * @delta: integer value to add + * @ptr: pointer to type atomic64_t + * + * Atomically adds @delta to @ptr and returns @delta + *@ptr + */ +extern u64 atomic64_add_return(u64 delta, atomic64_t *ptr); + +/* + * Other variants with different arithmetic operators: + */ +extern u64 atomic64_sub_return(u64 delta, atomic64_t *ptr); +extern u64 atomic64_inc_return(atomic64_t *ptr); +extern u64 atomic64_dec_return(atomic64_t *ptr); + +/** + * atomic64_add - add integer to atomic64 variable + * @delta: integer value to add + * @ptr: pointer to type atomic64_t + * + * Atomically adds @delta to @ptr. + */ +extern void atomic64_add(u64 delta, atomic64_t *ptr); + +/** + * atomic64_sub - subtract the atomic64 variable + * @delta: integer value to subtract + * @ptr: pointer to type atomic64_t + * + * Atomically subtracts @delta from @ptr. + */ +extern void atomic64_sub(u64 delta, atomic64_t *ptr); + +/** + * atomic64_sub_and_test - subtract value from variable and test result + * @delta: integer value to subtract + * @ptr: pointer to type atomic64_t + * + * Atomically subtracts @delta from @ptr and returns + * true if the result is zero, or false for all + * other cases. + */ +extern int atomic64_sub_and_test(u64 delta, atomic64_t *ptr); + +/** + * atomic64_inc - increment atomic64 variable + * @ptr: pointer to type atomic64_t + * + * Atomically increments @ptr by 1. + */ +extern void atomic64_inc(atomic64_t *ptr); + +/** + * atomic64_dec - decrement atomic64 variable + * @ptr: pointer to type atomic64_t + * + * Atomically decrements @ptr by 1. + */ +extern void atomic64_dec(atomic64_t *ptr); + +/** + * atomic64_dec_and_test - decrement and test + * @ptr: pointer to type atomic64_t + * + * Atomically decrements @ptr by 1 and + * returns true if the result is 0, or false for all other + * cases. + */ +extern int atomic64_dec_and_test(atomic64_t *ptr); + +/** + * atomic64_inc_and_test - increment and test + * @ptr: pointer to type atomic64_t + * + * Atomically increments @ptr by 1 + * and returns true if the result is zero, or false for all + * other cases. + */ +extern int atomic64_inc_and_test(atomic64_t *ptr); + +/** + * atomic64_add_negative - add and test if negative + * @delta: integer value to add + * @ptr: pointer to type atomic64_t + * + * Atomically adds @delta to @ptr and returns true + * if the result is negative, or false when + * result is greater than or equal to zero. + */ +extern int atomic64_add_negative(u64 delta, atomic64_t *ptr); + +#endif /* _ASM_X86_ATOMIC64_32_H */