summaryrefslogtreecommitdiff
path: root/arch/powerpc/lib
diff options
context:
space:
mode:
authorChristophe Leroy <christophe.leroy@csgroup.eu>2022-03-22 18:40:20 +0300
committerMichael Ellerman <mpe@ellerman.id.au>2022-05-11 16:06:39 +0300
commitb033767848c4115e486b1a51946de3bee2ac0fa6 (patch)
tree92673a5723ab58269ac2e7d458fa8f4e45643796 /arch/powerpc/lib
parentcb3ac45214c03852430979a43180371a44b74596 (diff)
downloadlinux-b033767848c4115e486b1a51946de3bee2ac0fa6.tar.xz
powerpc/code-patching: Use jump_label for testing freed initmem
Once init is done, initmem is freed forever so no need to test system_state at every call to patch_instruction(). Use jump_label. This reduces by 2% the time needed to activate ftrace on an 8xx. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/0aee964721cab7316cffde21a2ca223cee14d373.1647962456.git.christophe.leroy@csgroup.eu
Diffstat (limited to 'arch/powerpc/lib')
-rw-r--r--arch/powerpc/lib/code-patching.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code-patching.c
index f970f189875b..1ecd166091c9 100644
--- a/arch/powerpc/lib/code-patching.c
+++ b/arch/powerpc/lib/code-patching.c
@@ -8,6 +8,7 @@
#include <linux/init.h>
#include <linux/cpuhotplug.h>
#include <linux/uaccess.h>
+#include <linux/jump_label.h>
#include <asm/tlbflush.h>
#include <asm/page.h>
@@ -188,10 +189,12 @@ static int do_patch_instruction(u32 *addr, ppc_inst_t instr)
#endif /* CONFIG_STRICT_KERNEL_RWX */
+__ro_after_init DEFINE_STATIC_KEY_FALSE(init_mem_is_free);
+
int patch_instruction(u32 *addr, ppc_inst_t instr)
{
/* Make sure we aren't patching a freed init section */
- if (system_state >= SYSTEM_FREEING_INITMEM && init_section_contains(addr, 4))
+ if (static_branch_likely(&init_mem_is_free) && init_section_contains(addr, 4))
return 0;
return do_patch_instruction(addr, instr);