linux-kernel - [tip:x86/urgent] x86/kconfig: Disable CONFIG_GENERIC_HWEIGHT and remove __HAVE_ARCH_SW

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Date:   Mon, 13 May 2019 02:10:27 -0700
From:   tip-bot for Masahiro Yamada <tipbot@...or.com>
To:     linux-tip-commits@...r.kernel.org
Cc:     mingo@...nel.org, linux-kernel@...r.kernel.org, bp@...en8.de,
        yamada.masahiro@...ionext.com, tglx@...utronix.de,
        torvalds@...ux-foundation.org, hpa@...or.com, peterz@...radead.org,
        ubizjak@...il.com
Subject: [tip:x86/urgent] x86/kconfig: Disable CONFIG_GENERIC_HWEIGHT and
 remove __HAVE_ARCH_SW_HWEIGHT

Commit-ID:  409ca45526a428620d8efb362ccfd4b1e6b80642
Gitweb:     https://git.kernel.org/tip/409ca45526a428620d8efb362ccfd4b1e6b80642
Author:     Masahiro Yamada <yamada.masahiro@...ionext.com>
AuthorDate: Sun, 12 May 2019 21:52:01 +0900
Committer:  Ingo Molnar <mingo@...nel.org>
CommitDate: Mon, 13 May 2019 11:07:33 +0200

x86/kconfig: Disable CONFIG_GENERIC_HWEIGHT and remove __HAVE_ARCH_SW_HWEIGHT

Remove an unnecessary arch complication:

arch/x86/include/asm/arch_hweight.h uses __sw_hweight{32,64} as
alternatives, and they are implemented in arch/x86/lib/hweight.S

x86 does not rely on the generic C implementation lib/hweight.c
at all, so CONFIG_GENERIC_HWEIGHT should be disabled.

__HAVE_ARCH_SW_HWEIGHT is not necessary either.

No change in functionality intended.

Signed-off-by: Masahiro Yamada <yamada.masahiro@...ionext.com>
Cc: Borislav Petkov <bp@...en8.de>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: Uros Bizjak <ubizjak@...il.com>
Link: http://lkml.kernel.org/r/1557665521-17570-1-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Ingo Molnar <mingo@...nel.org>
---
 arch/x86/Kconfig                    | 3 ---
 arch/x86/include/asm/arch_hweight.h | 2 --
 lib/hweight.c                       | 4 ----
 3 files changed, 9 deletions(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 0a3cc347143f..de071d7e67b6 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -261,9 +261,6 @@ config GENERIC_BUG
 config GENERIC_BUG_RELATIVE_POINTERS
 	bool
 
-config GENERIC_HWEIGHT
-	def_bool y
-
 config ARCH_MAY_HAVE_PC_FDC
 	def_bool y
 	depends on ISA_DMA_API
diff --git a/arch/x86/include/asm/arch_hweight.h b/arch/x86/include/asm/arch_hweight.h
index fc0693569f7a..ba88edd0d58b 100644
--- a/arch/x86/include/asm/arch_hweight.h
+++ b/arch/x86/include/asm/arch_hweight.h
@@ -12,8 +12,6 @@
 #define REG_OUT "a"
 #endif
 
-#define __HAVE_ARCH_SW_HWEIGHT
-
 static __always_inline unsigned int __arch_hweight32(unsigned int w)
 {
 	unsigned int res;
diff --git a/lib/hweight.c b/lib/hweight.c
index 7660d88fd496..c94586b62551 100644
--- a/lib/hweight.c
+++ b/lib/hweight.c
@@ -10,7 +10,6 @@
  * The Hamming Weight of a number is the total number of bits set in it.
  */
 
-#ifndef __HAVE_ARCH_SW_HWEIGHT
 unsigned int __sw_hweight32(unsigned int w)
 {
 #ifdef CONFIG_ARCH_HAS_FAST_MULTIPLIER
@@ -27,7 +26,6 @@ unsigned int __sw_hweight32(unsigned int w)
 #endif
 }
 EXPORT_SYMBOL(__sw_hweight32);
-#endif
 
 unsigned int __sw_hweight16(unsigned int w)
 {
@@ -46,7 +44,6 @@ unsigned int __sw_hweight8(unsigned int w)
 }
 EXPORT_SYMBOL(__sw_hweight8);
 
-#ifndef __HAVE_ARCH_SW_HWEIGHT
 unsigned long __sw_hweight64(__u64 w)
 {
 #if BITS_PER_LONG == 32
@@ -69,4 +66,3 @@ unsigned long __sw_hweight64(__u64 w)
 #endif
 }
 EXPORT_SYMBOL(__sw_hweight64);
-#endif