From aecaf181651c91b8c89058708b065da9312a0ccd Mon Sep 17 00:00:00 2001
From: Alice Ryhl <aliceryhl@google.com>
Date: Wed, 30 Oct 2024 16:04:27 +0000
Subject: jump_label: adjust inline asm to be consistent

To avoid duplication of inline asm between C and Rust, we need to
import the inline asm from the relevant `jump_label.h` header into Rust.
To make that easier, this patch updates the header files to expose the
inline asm via a new ARCH_STATIC_BRANCH_ASM macro.

The header files are all updated to define a ARCH_STATIC_BRANCH_ASM that
takes the same arguments in a consistent order so that Rust can use the
same logic for every architecture.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Alex Gaynor <alex.gaynor@gmail.com>
Cc: Wedson Almeida Filho <wedsonaf@gmail.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Gary Guo <gary@garyguo.net>
Cc: " =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= " <bjorn3_gh@protonmail.com>
Cc: Benno Lossin <benno.lossin@proton.me>
Cc: Andreas Hindborg <a.hindborg@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Uros Bizjak <ubizjak@gmail.com>
Cc: Will Deacon <will@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Fuad Tabba <tabba@google.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Anup Patel <apatel@ventanamicro.com>
Cc: Andrew Jones <ajones@ventanamicro.com>
Cc: Alexandre Ghiti <alexghiti@rivosinc.com>
Cc: Conor Dooley <conor.dooley@microchip.com>
Cc: Samuel Holland <samuel.holland@sifive.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Bibo Mao <maobibo@loongson.cn>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tianrui Zhao <zhaotianrui@loongson.cn>
Cc: Palmer Dabbelt <palmer@rivosinc.com>
Link: https://lore.kernel.org/20241030-tracepoint-v12-4-eec7f0f8ad22@google.com
Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Co-developed-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com> # RISC-V
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 arch/loongarch/include/asm/jump_label.h | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

(limited to 'arch/loongarch')

diff --git a/arch/loongarch/include/asm/jump_label.h b/arch/loongarch/include/asm/jump_label.h
index 29acfe3de3fa..8a924bd69d19 100644
--- a/arch/loongarch/include/asm/jump_label.h
+++ b/arch/loongarch/include/asm/jump_label.h
@@ -13,18 +13,22 @@
 
 #define JUMP_LABEL_NOP_SIZE	4
 
-#define JUMP_TABLE_ENTRY				\
+/* This macro is also expanded on the Rust side. */
+#define JUMP_TABLE_ENTRY(key, label)			\
 	 ".pushsection	__jump_table, \"aw\"	\n\t"	\
 	 ".align	3			\n\t"	\
-	 ".long		1b - ., %l[l_yes] - .	\n\t"	\
-	 ".quad		%0 - .			\n\t"	\
+	 ".long		1b - ., " label " - .	\n\t"	\
+	 ".quad		" key " - .		\n\t"	\
 	 ".popsection				\n\t"
 
+#define ARCH_STATIC_BRANCH_ASM(key, label)		\
+	"1:	nop				\n\t"	\
+	JUMP_TABLE_ENTRY(key, label)
+
 static __always_inline bool arch_static_branch(struct static_key * const key, const bool branch)
 {
 	asm goto(
-		"1:	nop			\n\t"
-		JUMP_TABLE_ENTRY
+		ARCH_STATIC_BRANCH_ASM("%0", "%l[l_yes]")
 		:  :  "i"(&((char *)key)[branch]) :  : l_yes);
 
 	return false;
@@ -37,7 +41,7 @@ static __always_inline bool arch_static_branch_jump(struct static_key * const ke
 {
 	asm goto(
 		"1:	b	%l[l_yes]	\n\t"
-		JUMP_TABLE_ENTRY
+		JUMP_TABLE_ENTRY("%0", "%l[l_yes]")
 		:  :  "i"(&((char *)key)[branch]) :  : l_yes);
 
 	return false;
-- 
cgit