From: Peter Zijlstra <peterz@infradead.org>
To: x86@kernel.org, peterz@infradead.org, linux-kernel@vger.kernel.org
Cc: Josh Poimboeuf <jpoimboe@redhat.com>,
Steven Rostedt <rostedt@goodmis.org>,
Masami Hiramatsu <mhiramat@kernel.org>,
Daniel Bristot de Oliveira <bristot@redhat.com>,
Jason Baron <jbaron@akamai.com>, Nadav Amit <namit@vmware.com>,
Andy Lutomirski <luto@kernel.org>,
Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>,
Vineet Gupta <Vineet.Gupta1@synopsys.com>
Subject: [RFC][PATCH 3/8] jump_label, x86: Factor out the __jump_table generation
Date: Fri, 28 Jun 2019 12:21:16 +0200 [thread overview]
Message-ID: <20190628103224.602848654@infradead.org> (raw)
In-Reply-To: 20190628102113.360432762@infradead.org
Both arch_static_branch() and arch_static_branch_jump() have the same
blurb to generate the __jump_table entry, share it.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
arch/x86/include/asm/jump_label.h | 24 ++++++++++++------------
1 file changed, 12 insertions(+), 12 deletions(-)
--- a/arch/x86/include/asm/jump_label.h
+++ b/arch/x86/include/asm/jump_label.h
@@ -20,15 +20,19 @@
#include <linux/stringify.h>
#include <linux/types.h>
+#define JUMP_TABLE_ENTRY \
+ ".pushsection __jump_table, \"aw\" \n\t" \
+ _ASM_ALIGN "\n\t" \
+ ".long 1b - . \n\t" \
+ ".long %l[l_yes] - . \n\t" \
+ _ASM_PTR "%c0 + %c1 - .\n\t" \
+ ".popsection \n\t"
+
static __always_inline bool arch_static_branch(struct static_key *key, bool branch)
{
asm_volatile_goto("1:"
".byte " __stringify(STATIC_KEY_INIT_NOP) "\n\t"
- ".pushsection __jump_table, \"aw\" \n\t"
- _ASM_ALIGN "\n\t"
- ".long 1b - ., %l[l_yes] - . \n\t"
- _ASM_PTR "%c0 + %c1 - .\n\t"
- ".popsection \n\t"
+ JUMP_TABLE_ENTRY
: : "i" (key), "i" (branch) : : l_yes);
return false;
@@ -39,13 +43,9 @@ static __always_inline bool arch_static_
static __always_inline bool arch_static_branch_jump(struct static_key *key, bool branch)
{
asm_volatile_goto("1:"
- ".byte 0xe9\n\t .long %l[l_yes] - 2f\n\t"
- "2:\n\t"
- ".pushsection __jump_table, \"aw\" \n\t"
- _ASM_ALIGN "\n\t"
- ".long 1b - ., %l[l_yes] - . \n\t"
- _ASM_PTR "%c0 + %c1 - .\n\t"
- ".popsection \n\t"
+ ".byte 0xe9 \n\t"
+ ".long %l[l_yes] - (. + 4) \n\t"
+ JUMP_TABLE_ENTRY
: : "i" (key), "i" (branch) : : l_yes);
return false;
next prev parent reply other threads:[~2019-06-28 13:36 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-28 10:21 [RFC][PATCH 0/8] jump_label, x86: Support variable sized JMP instructions Peter Zijlstra
2019-06-28 10:21 ` [RFC][PATCH 1/8] x86/alternatives: Teach text_poke_bp() to emulate instructions Peter Zijlstra
2019-06-28 10:21 ` [RFC][PATCH 2/8] jump_label, x86: Strip ASM jump_label support Peter Zijlstra
2019-06-28 10:21 ` Peter Zijlstra [this message]
2019-06-28 10:21 ` [RFC][PATCH 4/8] jump_label, x86: Remove init NOP optimization Peter Zijlstra
2019-06-28 10:21 ` [RFC][PATCH 5/8] jump_label, x86: Improve error when we fail expected text Peter Zijlstra
2019-06-28 10:21 ` [RFC][PATCH 6/8] jump_label, x86: Add variable length patching support Peter Zijlstra
2019-06-28 10:21 ` [RFC][PATCH 7/8] jump_label, x86: Introduce jump_entry_size() Peter Zijlstra
2019-06-28 10:21 ` [RFC][PATCH 8/8] jump_label, x86: Enable JMP8/NOP2 support Peter Zijlstra
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