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From: "H. Peter Anvin" <hpa@linux.intel.com>
To: "H. Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Linus Torvalds <torvalds@linux-foundation.org>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Mario Gzuk <mariogzuk@technikz.de>,
	"H. Peter Anvin" <hpa@linux.intel.com>
Subject: [PATCH 3/8] x86, 386 removal: Remove CONFIG_XADD
Date: Wed, 28 Nov 2012 11:50:25 -0800
Message-ID: <1354132230-21854-4-git-send-email-hpa@linux.intel.com> (raw)
In-Reply-To: <1354132230-21854-1-git-send-email-hpa@linux.intel.com>

From: "H. Peter Anvin" <hpa@linux.intel.com>

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

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
---
 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
-- 
1.7.11.7


  parent reply index

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-11-28 19:50 [PATCH 0/8] RFC: Remove 386 support H. Peter Anvin
2012-11-28 19:50 ` [PATCH 1/8] x86, 386 removal: Remove CONFIG_M386 from Kconfig H. Peter Anvin
2012-12-01  0:34   ` [tip:x86/nuke386] " tip-bot for H. Peter Anvin
2012-11-28 19:50 ` [PATCH 2/8] x86, 386 removal: Remove CONFIG_CMPXCHG H. Peter Anvin
2012-12-01  0:35   ` [tip:x86/nuke386] " tip-bot for H. Peter Anvin
2012-11-28 19:50 ` H. Peter Anvin [this message]
2012-11-28 20:30   ` [PATCH 3/8] x86, 386 removal: Remove CONFIG_XADD Borislav Petkov
2012-12-01  0:36   ` [tip:x86/nuke386] " tip-bot for H. Peter Anvin
2012-11-28 19:50 ` [PATCH 4/8] x86, 386 removal: Remove CONFIG_BSWAP H. Peter Anvin
2012-12-01  0:37   ` [tip:x86/nuke386] " tip-bot for H. Peter Anvin
2012-11-28 19:50 ` [PATCH 5/8] x86, 386 removal: Remove CONFIG_INVLPG H. Peter Anvin
2012-12-01  0:38   ` [tip:x86/nuke386] " tip-bot for H. Peter Anvin
2012-11-28 19:50 ` [PATCH 6/8] x86, 386 removal: Remove CONFIG_X86_WP_WORKS_OK H. Peter Anvin
2012-11-28 20:52   ` Alan Cox
2012-11-28 23:11     ` H. Peter Anvin
2012-12-01  0:42     ` [tip:x86/nuke386] x86, 386 removal: Document Nx586 as a 386 and thus unsupported tip-bot for H. Peter Anvin
2012-12-01  0:39   ` [tip:x86/nuke386] x86, 386 removal: Remove CONFIG_X86_WP_WORKS_OK tip-bot for H. Peter Anvin
2012-11-28 19:50 ` [PATCH 7/8] x86, 386 removal: Remove CONFIG_X86_POPAD_OK H. Peter Anvin
2012-12-01  0:40   ` [tip:x86/nuke386] " tip-bot for H. Peter Anvin
2012-11-28 19:50 ` [PATCH 8/8] x86, cleanups: Simplify sync_core() in the case of no CPUID H. Peter Anvin
2012-11-28 20:41   ` Borislav Petkov
2012-11-29  0:14     ` H. Peter Anvin
2012-11-29  9:13       ` Borislav Petkov
2012-11-29 21:06         ` H. Peter Anvin
2012-11-29 21:18           ` Borislav Petkov
2012-11-29 21:20             ` H. Peter Anvin
2012-11-29 21:31               ` Borislav Petkov
2012-11-29 21:24     ` H. Peter Anvin
2012-11-29 21:34       ` Borislav Petkov
2012-11-30 17:01       ` Linus Torvalds
2012-11-30 17:28         ` Borislav Petkov
2012-11-30 18:03         ` H. Peter Anvin
2012-11-30 18:10           ` Borislav Petkov
2012-11-30 18:40             ` H. Peter Anvin
2012-12-01  0:41   ` [tip:x86/nuke386] " tip-bot for H. Peter Anvin

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