[Xen-devel] [PATCH RFC 5/8] mips/jump_label: add arch_jump_label_transform_early()

[Jeremy Fitzhardinge <jeremy@xxxxxxxx>]

From: Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>

This allows jump-label entries to be modified early, in a pre-SMP
environment.

XXX TODO: make sure idling CPUs flush their icaches before continuing
in case this modifies something that's adjacent to their init-idle loops.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>
Cc: David Daney <david.daney@xxxxxxxxxx>
---
 arch/mips/kernel/jump_label.c |   21 +++++++++++++++++----
 1 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/arch/mips/kernel/jump_label.c b/arch/mips/kernel/jump_label.c
index 6001610..ddc9a65 100644
--- a/arch/mips/kernel/jump_label.c
+++ b/arch/mips/kernel/jump_label.c
@@ -20,8 +20,8 @@
 
 #define J_RANGE_MASK ((1ul << 28) - 1)
 
-void arch_jump_label_transform(struct jump_entry *e,
-                              enum jump_label_type type)
+static void __jump_label_transform(struct jump_entry *e,
+                                  enum jump_label_type type)
 {
        union mips_instruction insn;
        union mips_instruction *insn_p =
@@ -40,15 +40,28 @@ void arch_jump_label_transform(struct jump_entry *e,
                insn.word = 0; /* nop */
        }
 
-       get_online_cpus();
-       mutex_lock(&text_mutex);
        *insn_p = insn;
 
        flush_icache_range((unsigned long)insn_p,
                           (unsigned long)insn_p + sizeof(*insn_p));
+}
+
+void arch_jump_label_transform(struct jump_entry *e,
+                              enum jump_label_type type)
+{
+       get_online_cpus();
+       mutex_lock(&text_mutex);
+
+       __jump_label_tranform(e, type);
 
        mutex_unlock(&text_mutex);
        put_online_cpus();
 }
 
+void __init arch_jump_label_transform_early(struct jump_entry *e,
+                                           enum jump_label_type type)
+{
+       __jump_label_tranform(e, type);
+}
+
 #endif /* HAVE_JUMP_LABEL */
-- 
1.7.6.2


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