[PATCH RFC V4 07/10] s390/jump-label: add arch_jump_label_transform_static()

Jeremy Fitzhardinge
2011-10-13T00:09:00Z

From: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

This allows jump-label entries to be cheaply updated on code which is
not yet live.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: Jason Baron <jbaron@redhat.com>
Cc: Jan Glauber <jang@linux.vnet.ibm.com>
---
arch/s390/kernel/jump_label.c | 51 +++++++++++++++++++++++++----------------
1 files changed, 31 insertions(+), 20 deletions(-)

diff --git a/arch/s390/kernel/jump_label.c b/arch/s390/kernel/jump_label.c
index 44cc06b..b987ab2 100644
--- a/arch/s390/kernel/jump_label.c
+++ b/arch/s390/kernel/jump_label.c
@@ -18,26 +18,15 @@ struct insn {
} __packed;

struct insn_args {
- unsigned long *target;
- struct insn *insn;
- ssize_t size;
+ struct jump_entry *entry;
+ enum jump_label_type type;
};

-static int __arch_jump_label_transform(void *data)
+static void __jump_label_transform(struct jump_entry *entry,
+ enum jump_label_type type)
{
- struct insn_args *args = data;
- int rc;
-
- rc = probe_kernel_write(args->target, args->insn, args->size);
- WARN_ON_ONCE(rc < 0);
- return 0;
-}
-
-void arch_jump_label_transform(struct jump_entry *entry,
- enum jump_label_type type)
-{
- struct insn_args args;
struct insn insn;
+ int rc;

if (type == JUMP_LABEL_ENABLE) {
/* brcl 15,offset */
@@ -49,11 +38,33 @@ void arch_jump_label_transform(struct jump_entry *entry,
insn.offset = 0;
}

- args.target = (void *) entry->code;
- args.insn = &insn;
- args.size = JUMP_LABEL_NOP_SIZE;
+ rc = probe_kernel_write((void *)entry->code, &insn, JUMP_LABEL_NOP_SIZE);
+ WARN_ON_ONCE(rc < 0);
+}

- stop_machine(__arch_jump_label_transform, &args, NULL);
+static int __sm_arch_jump_label_transform(void *data)
+{
+ struct insn_args *args = data;
+
+ __jump_label_transform(args->entry, args->type);
+ return 0;
+}
+
+void arch_jump_label_transform(struct jump_entry *entry,
+ enum jump_label_type type)
+{
+ struct insn_args args;
+
+ args.entry = entry;
+ args.type = type;
+
+ stop_machine(__sm_arch_jump_label_transform, &args, NULL);
+}
+
+void arch_jump_label_transform_static(struct jump_entry *entry,
+ enum jump_label_type type)
+{
+ __jump_label_transform(entry, type);
}

#endif
--
1.7.6.4