Commit e9666d10 authored by Masahiro Yamada's avatar Masahiro Yamada
Browse files

jump_label: move 'asm goto' support test to Kconfig



Currently, CONFIG_JUMP_LABEL just means "I _want_ to use jump label".

The jump label is controlled by HAVE_JUMP_LABEL, which is defined
like this:

  #if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL)
  # define HAVE_JUMP_LABEL
  #endif

We can improve this by testing 'asm goto' support in Kconfig, then
make JUMP_LABEL depend on CC_HAS_ASM_GOTO.

Ugly #ifdef HAVE_JUMP_LABEL will go away, and CONFIG_JUMP_LABEL will
match to the real kernel capability.
Signed-off-by: default avatarMasahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Tested-by: default avatarSedat Dilek <sedat.dilek@gmail.com>
parent 72d3ebb9
......@@ -514,13 +514,6 @@ RETPOLINE_VDSO_CFLAGS := $(call cc-option,$(RETPOLINE_VDSO_CFLAGS_GCC),$(call cc
export RETPOLINE_CFLAGS
export RETPOLINE_VDSO_CFLAGS
# check for 'asm goto'
ifeq ($(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-goto.sh $(CC) $(KBUILD_CFLAGS)), y)
CC_HAVE_ASM_GOTO := 1
KBUILD_CFLAGS += -DCC_HAVE_ASM_GOTO
KBUILD_AFLAGS += -DCC_HAVE_ASM_GOTO
endif
# The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
# Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
# CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
......
......@@ -71,6 +71,7 @@ config KPROBES
config JUMP_LABEL
bool "Optimize very unlikely/likely branches"
depends on HAVE_ARCH_JUMP_LABEL
depends on CC_HAS_ASM_GOTO
help
This option enables a transparent branch optimization that
makes certain almost-always-true or almost-always-false branch
......
......@@ -4,8 +4,6 @@
#include <asm/patch.h>
#include <asm/insn.h>
#ifdef HAVE_JUMP_LABEL
static void __arch_jump_label_transform(struct jump_entry *entry,
enum jump_label_type type,
bool is_static)
......@@ -35,5 +33,3 @@ void arch_jump_label_transform_static(struct jump_entry *entry,
{
__arch_jump_label_transform(entry, type, true);
}
#endif
......@@ -20,8 +20,6 @@
#include <linux/jump_label.h>
#include <asm/insn.h>
#ifdef HAVE_JUMP_LABEL
void arch_jump_label_transform(struct jump_entry *entry,
enum jump_label_type type)
{
......@@ -49,5 +47,3 @@ void arch_jump_label_transform_static(struct jump_entry *entry,
* NOP needs to be replaced by a branch.
*/
}
#endif /* HAVE_JUMP_LABEL */
......@@ -16,8 +16,6 @@
#include <asm/cacheflush.h>
#include <asm/inst.h>
#ifdef HAVE_JUMP_LABEL
/*
* Define parameters for the standard MIPS and the microMIPS jump
* instruction encoding respectively:
......@@ -70,5 +68,3 @@ void arch_jump_label_transform(struct jump_entry *e,
mutex_unlock(&text_mutex);
}
#endif /* HAVE_JUMP_LABEL */
......@@ -38,7 +38,7 @@ extern struct static_key hcall_tracepoint_key;
void __trace_hcall_entry(unsigned long opcode, unsigned long *args);
void __trace_hcall_exit(long opcode, long retval, unsigned long *retbuf);
/* OPAL tracing */
#ifdef HAVE_JUMP_LABEL
#ifdef CONFIG_JUMP_LABEL
extern struct static_key opal_tracepoint_key;
#endif
......
......@@ -11,7 +11,6 @@
#include <linux/jump_label.h>
#include <asm/code-patching.h>
#ifdef HAVE_JUMP_LABEL
void arch_jump_label_transform(struct jump_entry *entry,
enum jump_label_type type)
{
......@@ -22,4 +21,3 @@ void arch_jump_label_transform(struct jump_entry *entry,
else
patch_instruction(addr, PPC_INST_NOP);
}
#endif
......@@ -4,7 +4,7 @@
#include <asm/trace.h>
#include <asm/asm-prototypes.h>
#ifdef HAVE_JUMP_LABEL
#ifdef CONFIG_JUMP_LABEL
struct static_key opal_tracepoint_key = STATIC_KEY_INIT;
int opal_tracepoint_regfunc(void)
......
......@@ -20,7 +20,7 @@
.section ".text"
#ifdef CONFIG_TRACEPOINTS
#ifdef HAVE_JUMP_LABEL
#ifdef CONFIG_JUMP_LABEL
#define OPAL_BRANCH(LABEL) \
ARCH_STATIC_BRANCH(LABEL, opal_tracepoint_key)
#else
......
......@@ -19,7 +19,7 @@
#ifdef CONFIG_TRACEPOINTS
#ifndef HAVE_JUMP_LABEL
#ifndef CONFIG_JUMP_LABEL
.section ".toc","aw"
.globl hcall_tracepoint_refcount
......@@ -79,7 +79,7 @@ hcall_tracepoint_refcount:
mr r5,BUFREG; \
__HCALL_INST_POSTCALL
#ifdef HAVE_JUMP_LABEL
#ifdef CONFIG_JUMP_LABEL
#define HCALL_BRANCH(LABEL) \
ARCH_STATIC_BRANCH(LABEL, hcall_tracepoint_key)
#else
......
......@@ -1040,7 +1040,7 @@ EXPORT_SYMBOL(arch_free_page);
#endif /* CONFIG_PPC_BOOK3S_64 */
#ifdef CONFIG_TRACEPOINTS
#ifdef HAVE_JUMP_LABEL
#ifdef CONFIG_JUMP_LABEL
struct static_key hcall_tracepoint_key = STATIC_KEY_INIT;
int hcall_tracepoint_regfunc(void)
......
......@@ -48,7 +48,7 @@ CFLAGS_ptrace.o += -DUTS_MACHINE='"$(UTS_MACHINE)"'
obj-y := traps.o time.o process.o base.o early.o setup.o idle.o vtime.o
obj-y += processor.o sys_s390.o ptrace.o signal.o cpcmd.o ebcdic.o nmi.o
obj-y += debug.o irq.o ipl.o dis.o diag.o vdso.o early_nobss.o
obj-y += sysinfo.o jump_label.o lgr.o os_info.o machine_kexec.o pgm_check.o
obj-y += sysinfo.o lgr.o os_info.o machine_kexec.o pgm_check.o
obj-y += runtime_instr.o cache.o fpu.o dumpstack.o guarded_storage.o sthyi.o
obj-y += entry.o reipl.o relocate_kernel.o kdebugfs.o alternative.o
obj-y += nospec-branch.o ipl_vmparm.o
......@@ -72,6 +72,7 @@ obj-$(CONFIG_KPROBES) += kprobes.o
obj-$(CONFIG_FUNCTION_TRACER) += mcount.o ftrace.o
obj-$(CONFIG_CRASH_DUMP) += crash_dump.o
obj-$(CONFIG_UPROBES) += uprobes.o
obj-$(CONFIG_JUMP_LABEL) += jump_label.o
obj-$(CONFIG_KEXEC_FILE) += machine_kexec_file.o kexec_image.o
obj-$(CONFIG_KEXEC_FILE) += kexec_elf.o
......
......@@ -10,8 +10,6 @@
#include <linux/jump_label.h>
#include <asm/ipl.h>
#ifdef HAVE_JUMP_LABEL
struct insn {
u16 opcode;
s32 offset;
......@@ -103,5 +101,3 @@ void arch_jump_label_transform_static(struct jump_entry *entry,
{
__jump_label_transform(entry, type, 1);
}
#endif
......@@ -118,4 +118,4 @@ pc--$(CONFIG_PERF_EVENTS) := perf_event.o
obj-$(CONFIG_SPARC64) += $(pc--y)
obj-$(CONFIG_UPROBES) += uprobes.o
obj-$(CONFIG_SPARC64) += jump_label.o
obj-$(CONFIG_JUMP_LABEL) += jump_label.o
......@@ -9,8 +9,6 @@
#include <asm/cacheflush.h>
#ifdef HAVE_JUMP_LABEL
void arch_jump_label_transform(struct jump_entry *entry,
enum jump_label_type type)
{
......@@ -47,5 +45,3 @@ void arch_jump_label_transform(struct jump_entry *entry,
flushi(insn);
mutex_unlock(&text_mutex);
}
#endif
......@@ -289,7 +289,7 @@ vdso_install:
archprepare: checkbin
checkbin:
ifndef CC_HAVE_ASM_GOTO
ifndef CONFIG_CC_HAS_ASM_GOTO
@echo Compiler lacks asm-goto support.
@exit 1
endif
......
......@@ -351,7 +351,7 @@ For 32-bit we have the following conventions - kernel is built with
*/
.macro CALL_enter_from_user_mode
#ifdef CONFIG_CONTEXT_TRACKING
#ifdef HAVE_JUMP_LABEL
#ifdef CONFIG_JUMP_LABEL
STATIC_JUMP_IF_FALSE .Lafter_call_\@, context_tracking_enabled, def=0
#endif
call enter_from_user_mode
......
......@@ -140,7 +140,7 @@ extern void clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int bit);
#define setup_force_cpu_bug(bit) setup_force_cpu_cap(bit)
#if defined(__clang__) && !defined(CC_HAVE_ASM_GOTO)
#if defined(__clang__) && !defined(CONFIG_CC_HAS_ASM_GOTO)
/*
* Workaround for the sake of BPF compilation which utilizes kernel
......
......@@ -2,19 +2,6 @@
#ifndef _ASM_X86_JUMP_LABEL_H
#define _ASM_X86_JUMP_LABEL_H
#ifndef HAVE_JUMP_LABEL
/*
* For better or for worse, if jump labels (the gcc extension) are missing,
* then the entire static branch patching infrastructure is compiled out.
* If that happens, the code in here will malfunction. Raise a compiler
* error instead.
*
* In theory, jump labels and the static branch patching infrastructure
* could be decoupled to fix this.
*/
#error asm/jump_label.h included on a non-jump-label kernel
#endif
#define JUMP_LABEL_NOP_SIZE 5
#ifdef CONFIG_X86_64
......
......@@ -11,7 +11,7 @@
#define __CLOBBERS_MEM(clb...) "memory", ## clb
#if !defined(__GCC_ASM_FLAG_OUTPUTS__) && defined(CC_HAVE_ASM_GOTO)
#if !defined(__GCC_ASM_FLAG_OUTPUTS__) && defined(CONFIG_CC_HAS_ASM_GOTO)
/* Use asm goto */
......@@ -27,7 +27,7 @@ cc_label: c = true; \
c; \
})
#else /* defined(__GCC_ASM_FLAG_OUTPUTS__) || !defined(CC_HAVE_ASM_GOTO) */
#else /* defined(__GCC_ASM_FLAG_OUTPUTS__) || !defined(CONFIG_CC_HAS_ASM_GOTO) */
/* Use flags output or a set instruction */
......@@ -40,7 +40,7 @@ cc_label: c = true; \
c; \
})
#endif /* defined(__GCC_ASM_FLAG_OUTPUTS__) || !defined(CC_HAVE_ASM_GOTO) */
#endif /* defined(__GCC_ASM_FLAG_OUTPUTS__) || !defined(CONFIG_CC_HAS_ASM_GOTO) */
#define GEN_UNARY_RMWcc_4(op, var, cc, arg0) \
__GEN_RMWcc(op " " arg0, var, cc, __CLOBBERS_MEM())
......
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