powerpc/mm: Catch usage of cpu/mmu_has_feature() before jump label init
This allows us to catch incorrect usage of cpu_has_feature() and
mmu_has_feature() prior to jump labels being initialised.
mpe: Use printk() and dump_stack() rather than WARN_ON(), because
WARN_ON() may not work this early in boot. Rename the Kconfig.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/arch/powerpc/include/asm/mmu.h b/arch/powerpc/include/asm/mmu.h
index 1bf919a..e2fb408 100644
--- a/arch/powerpc/include/asm/mmu.h
+++ b/arch/powerpc/include/asm/mmu.h
@@ -156,6 +156,14 @@
BUILD_BUG_ON(!__builtin_constant_p(feature));
+#ifdef CONFIG_JUMP_LABEL_FEATURE_CHECK_DEBUG
+ if (!static_key_initialized) {
+ printk("Warning! mmu_has_feature() used prior to jump label init!\n");
+ dump_stack();
+ return early_mmu_has_feature(feature);
+ }
+#endif
+
if (!(MMU_FTRS_POSSIBLE & feature))
return false;