Commit a6b3eb30 authored by Will Deacon's avatar Will Deacon
Browse files

Revert "arm64: jump_label: use constraints "Si" instead of "i"" 



This reverts commit f9daab0a.

Geert reports that his particular GCC 5.5 vintage toolchain fails to
build an arm64 defconfig because of this change:

 |    arch/arm64/include/asm/jump_label.h:25:2: error: invalid 'asm':
 | invalid operand
 |     asm goto(
      ^
Aopparently, this is something we claim to support, so let's revert back
to the old jump label constraint for now while discussions about raising
the minimum GCC version are ongoing.

Reported-by: default avatarGeert Uytterhoeven <geert@linux-m68k.org>
Link: https://lore.kernel.org/r/CAMuHMdX+6fnAf8Hm6EqYJPAjrrLO9T7c=Gu3S8V_pqjSDowJ6g@mail.gmail.com


Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent 802379b8

arch/arm64/include/asm/jump_label.h

+4 −8
Original line number Diff line number Diff line
@@ -15,10 +15,6 @@ 


#define JUMP_LABEL_NOP_SIZE		AARCH64_INSN_SIZE



/*

 * Prefer the constraint "S" to support PIC with GCC. Clang before 19 does not

 * support "S" on a symbol with a constant offset, so we use "i" as a fallback.

 */

static __always_inline bool arch_static_branch(struct static_key * const key,

					       const bool branch)

{
@@ -27,9 +23,9 @@ static __always_inline bool arch_static_branch(struct static_key * const key, 
		 "	.pushsection	__jump_table, \"aw\"	\n\t"

		 "	.align		3			\n\t"

		 "	.long		1b - ., %l[l_yes] - .	\n\t"

		 "	.quad		(%[key] - .) + %[bit0]  \n\t"

		 "	.quad		%c0 - .			\n\t"

		 "	.popsection				\n\t"

		 :  :  [key]"Si"(key), [bit0]"i"(branch) :  : l_yes);

		 :  :  "i"(&((char *)key)[branch]) :  : l_yes);



	return false;

l_yes:
@@ -44,9 +40,9 @@ static __always_inline bool arch_static_branch_jump(struct static_key * const ke 
		 "	.pushsection	__jump_table, \"aw\"	\n\t"

		 "	.align		3			\n\t"

		 "	.long		1b - ., %l[l_yes] - .	\n\t"

		 "	.quad		(%[key] - .) + %[bit0]  \n\t"

		 "	.quad		%c0 - .			\n\t"

		 "	.popsection				\n\t"

		 :  :  [key]"Si"(key), [bit0]"i"(branch) :  : l_yes);

		 :  :  "i"(&((char *)key)[branch]) :  : l_yes);



	return false;

l_yes: