[tip:x86/nuke386] x86, 386 removal: Remove CONFIG_XADD

From: tip-bot for H. Peter Anvin
Date: Fri Nov 30 2012 - 19:36:44 EST


Commit-ID: 7ac468b1300f35143a9b5b100e3970ca7ae1d9b8
Gitweb: http://git.kernel.org/tip/7ac468b1300f35143a9b5b100e3970ca7ae1d9b8
Author: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx>
AuthorDate: Wed, 28 Nov 2012 11:50:25 -0800
Committer: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx>
CommitDate: Thu, 29 Nov 2012 13:23:02 -0800

x86, 386 removal: Remove CONFIG_XADD

All 486+ CPUs support XADD, so remove the fallback 386 support
code.

Signed-off-by: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/1354132230-21854-4-git-send-email-hpa@xxxxxxxxxxxxxxx
---
arch/x86/Kconfig | 5 -----
arch/x86/Kconfig.cpu | 3 ---
arch/x86/include/asm/atomic.h | 16 ----------------
arch/x86/include/asm/local.h | 18 +-----------------
arch/x86/um/Kconfig | 2 +-
5 files changed, 2 insertions(+), 42 deletions(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index a1a6627..631b298 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -171,13 +171,8 @@ config ARCH_MAY_HAVE_PC_FDC
def_bool y
depends on ISA_DMA_API

-config RWSEM_GENERIC_SPINLOCK
- def_bool y
- depends on !X86_XADD
-
config RWSEM_XCHGADD_ALGORITHM
def_bool y
- depends on X86_XADD

config GENERIC_CALIBRATE_DELAY
def_bool y
diff --git a/arch/x86/Kconfig.cpu b/arch/x86/Kconfig.cpu
index 1290a69..52955ee 100644
--- a/arch/x86/Kconfig.cpu
+++ b/arch/x86/Kconfig.cpu
@@ -304,9 +304,6 @@ config X86_L1_CACHE_SHIFT
default "4" if MELAN || M486 || MGEODEGX1
default "5" if MWINCHIP3D || MWINCHIPC6 || MCRUSOE || MEFFICEON || MCYRIXIII || MK6 || MPENTIUMIII || MPENTIUMII || M686 || M586MMX || M586TSC || M586 || MVIAC3_2 || MGEODE_LX

-config X86_XADD
- def_bool y
-
config X86_PPRO_FENCE
bool "PentiumPro memory ordering errata workaround"
depends on M686 || M586MMX || M586TSC || M586 || M486 || MGEODEGX1
diff --git a/arch/x86/include/asm/atomic.h b/arch/x86/include/asm/atomic.h
index b6c3b82..722aa3b 100644
--- a/arch/x86/include/asm/atomic.h
+++ b/arch/x86/include/asm/atomic.h
@@ -172,23 +172,7 @@ static inline int atomic_add_negative(int i, atomic_t *v)
*/
static inline int atomic_add_return(int i, atomic_t *v)
{
-#ifdef CONFIG_M386
- int __i;
- unsigned long flags;
- if (unlikely(boot_cpu_data.x86 <= 3))
- goto no_xadd;
-#endif
- /* Modern 486+ processor */
return i + xadd(&v->counter, i);
-
-#ifdef CONFIG_M386
-no_xadd: /* Legacy 386 processor */
- raw_local_irq_save(flags);
- __i = atomic_read(v);
- atomic_set(v, i + __i);
- raw_local_irq_restore(flags);
- return i + __i;
-#endif
}

/**
diff --git a/arch/x86/include/asm/local.h b/arch/x86/include/asm/local.h
index c8bed0d..2d89e39 100644
--- a/arch/x86/include/asm/local.h
+++ b/arch/x86/include/asm/local.h
@@ -124,27 +124,11 @@ static inline int local_add_negative(long i, local_t *l)
*/
static inline long local_add_return(long i, local_t *l)
{
- long __i;
-#ifdef CONFIG_M386
- unsigned long flags;
- if (unlikely(boot_cpu_data.x86 <= 3))
- goto no_xadd;
-#endif
- /* Modern 486+ processor */
- __i = i;
+ long __i = i;
asm volatile(_ASM_XADD "%0, %1;"
: "+r" (i), "+m" (l->a.counter)
: : "memory");
return i + __i;
-
-#ifdef CONFIG_M386
-no_xadd: /* Legacy 386 processor */
- local_irq_save(flags);
- __i = local_read(l);
- local_set(l, i + __i);
- local_irq_restore(flags);
- return i + __i;
-#endif
}

static inline long local_sub_return(long i, local_t *l)
diff --git a/arch/x86/um/Kconfig b/arch/x86/um/Kconfig
index 0761175..b0c30da 100644
--- a/arch/x86/um/Kconfig
+++ b/arch/x86/um/Kconfig
@@ -31,7 +31,7 @@ config X86_64
select MODULES_USE_ELF_RELA

config RWSEM_XCHGADD_ALGORITHM
- def_bool X86_XADD && 64BIT
+ def_bool 64BIT

config RWSEM_GENERIC_SPINLOCK
def_bool !RWSEM_XCHGADD_ALGORITHM
--
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