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Date: Wed, 28 Nov 2012 11:50:26 -0800
From: "H. Peter Anvin" <hpa@...ux.intel.com>
To: "H. Peter Anvin" <hpa@...or.com>, Ingo Molnar <mingo@...nel.org>,
Thomas Gleixner <tglx@...utronix.de>,
Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
Mario Gzuk <mariogzuk@...hnikz.de>,
"H. Peter Anvin" <hpa@...ux.intel.com>
Subject: [PATCH 4/8] x86, 386 removal: Remove CONFIG_BSWAP
From: "H. Peter Anvin" <hpa@...ux.intel.com>
All 486+ CPUs support BSWAP, so remove the fallback 386 support
code.
Signed-off-by: H. Peter Anvin <hpa@...ux.intel.com>
---
arch/x86/Kconfig.cpu | 4 ----
arch/x86/include/asm/futex.h | 12 ------------
arch/x86/include/asm/swab.h | 29 ++---------------------------
arch/x86/kernel/cpu/bugs.c | 13 ++-----------
4 files changed, 4 insertions(+), 54 deletions(-)
diff --git a/arch/x86/Kconfig.cpu b/arch/x86/Kconfig.cpu
index 52955ee..8e5867c 100644
--- a/arch/x86/Kconfig.cpu
+++ b/arch/x86/Kconfig.cpu
@@ -332,10 +332,6 @@ config X86_INVLPG
def_bool y
depends on X86_32
-config X86_BSWAP
- def_bool y
- depends on X86_32
-
config X86_POPAD_OK
def_bool y
depends on X86_32
diff --git a/arch/x86/include/asm/futex.h b/arch/x86/include/asm/futex.h
index f373046..be27ba1 100644
--- a/arch/x86/include/asm/futex.h
+++ b/arch/x86/include/asm/futex.h
@@ -55,12 +55,6 @@ static inline int futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr)
if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
return -EFAULT;
-#if defined(CONFIG_X86_32) && !defined(CONFIG_X86_BSWAP)
- /* Real i386 machines can only support FUTEX_OP_SET */
- if (op != FUTEX_OP_SET && boot_cpu_data.x86 == 3)
- return -ENOSYS;
-#endif
-
pagefault_disable();
switch (op) {
@@ -118,12 +112,6 @@ static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
{
int ret = 0;
-#if defined(CONFIG_X86_32) && !defined(CONFIG_X86_BSWAP)
- /* Real i386 machines have no cmpxchg instruction */
- if (boot_cpu_data.x86 == 3)
- return -ENOSYS;
-#endif
-
if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
return -EFAULT;
diff --git a/arch/x86/include/asm/swab.h b/arch/x86/include/asm/swab.h
index 557cd9f..7f235c7 100644
--- a/arch/x86/include/asm/swab.h
+++ b/arch/x86/include/asm/swab.h
@@ -6,22 +6,7 @@
static inline __attribute_const__ __u32 __arch_swab32(__u32 val)
{
-#ifdef __i386__
-# ifdef CONFIG_X86_BSWAP
- asm("bswap %0" : "=r" (val) : "0" (val));
-# else
- asm("xchgb %b0,%h0\n\t" /* swap lower bytes */
- "rorl $16,%0\n\t" /* swap words */
- "xchgb %b0,%h0" /* swap higher bytes */
- : "=q" (val)
- : "0" (val));
-# endif
-
-#else /* __i386__ */
- asm("bswapl %0"
- : "=r" (val)
- : "0" (val));
-#endif
+ asm("bswapl %0" : "=r" (val) : "0" (val));
return val;
}
#define __arch_swab32 __arch_swab32
@@ -37,22 +22,12 @@ static inline __attribute_const__ __u64 __arch_swab64(__u64 val)
__u64 u;
} v;
v.u = val;
-# ifdef CONFIG_X86_BSWAP
asm("bswapl %0 ; bswapl %1 ; xchgl %0,%1"
: "=r" (v.s.a), "=r" (v.s.b)
: "0" (v.s.a), "1" (v.s.b));
-# else
- v.s.a = __arch_swab32(v.s.a);
- v.s.b = __arch_swab32(v.s.b);
- asm("xchgl %0,%1"
- : "=r" (v.s.a), "=r" (v.s.b)
- : "0" (v.s.a), "1" (v.s.b));
-# endif
return v.u;
#else /* __i386__ */
- asm("bswapq %0"
- : "=r" (val)
- : "0" (val));
+ asm("bswapq %0" : "=r" (val) : "0" (val));
return val;
#endif
}
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index d0e910d..0cd07cc 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -136,24 +136,15 @@ static void __init check_popad(void)
/*
* Check whether we are able to run this kernel safely on SMP.
*
- * - In order to run on a i386, we need to be compiled for i386
- * (for due to lack of "invlpg" and working WP on a i386)
+ * - i386 is no longer supported.
* - In order to run on anything without a TSC, we need to be
* compiled for a i486.
*/
static void __init check_config(void)
{
-/*
- * We'd better not be a i386 if we're configured to use some
- * i486+ only features! (WP works in supervisor mode and the
- * new "invlpg" and "bswap" instructions)
- */
-#if defined(CONFIG_X86_WP_WORKS_OK) || defined(CONFIG_X86_INVLPG) || \
- defined(CONFIG_X86_BSWAP)
- if (boot_cpu_data.x86 == 3)
+ if (boot_cpu_data.x86 < 4)
panic("Kernel requires i486+ for 'invlpg' and other features");
-#endif
}
--
1.7.11.7
--
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