fix(cpufeat): make stub enable functions "static inline"
For builds where we don't have a certain feature enabled, we provide
empty stub xxx_enable() functions in a header file. This way we
avoid #ifdef's in the code, and can call the enable function
unconditionally. When compiling with -O1 or higher, the compiler will
even optimise out the whole call, so the symbol will never make it into
any object file.
When compiling with optimisations turned off, the function stub will
survive, and could make it into multiple object files, which would lead
to a multiple definitons error.
Avoid this by defining those stub functions as "static inline". The
"static" will avoid the multiple definitions problems, the "inline" will
avoid a potential compiler warning about unused functions.
This patterns is used extensively in the Linux kernel.
Change-Id: Iad07bb946aab372587c83f2423b4983bf3817990
Reported-by: Chris Kay <chris.kay@arm.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
diff --git a/include/lib/extensions/brbe.h b/include/lib/extensions/brbe.h
index aee208d..9ee2444 100644
--- a/include/lib/extensions/brbe.h
+++ b/include/lib/extensions/brbe.h
@@ -10,7 +10,7 @@
#if ENABLE_BRBE_FOR_NS
void brbe_enable(void);
#else
-void brbe_enable(void)
+static inline void brbe_enable(void)
{
}
#endif /* ENABLE_BRBE_FOR_NS */
diff --git a/include/lib/extensions/mpam.h b/include/lib/extensions/mpam.h
index 120a921..4327278 100644
--- a/include/lib/extensions/mpam.h
+++ b/include/lib/extensions/mpam.h
@@ -12,7 +12,7 @@
#if ENABLE_MPAM_FOR_LOWER_ELS
void mpam_enable(bool el2_unused);
#else
-void mpam_enable(bool el2_unused)
+static inline void mpam_enable(bool el2_unused)
{
}
#endif
diff --git a/include/lib/extensions/spe.h b/include/lib/extensions/spe.h
index d443f18..02fccae 100644
--- a/include/lib/extensions/spe.h
+++ b/include/lib/extensions/spe.h
@@ -13,10 +13,10 @@
void spe_enable(bool el2_unused);
void spe_disable(void);
#else
-void spe_enable(bool el2_unused)
+static inline void spe_enable(bool el2_unused)
{
}
-void spe_disable(void)
+static inline void spe_disable(void)
{
}
#endif
diff --git a/include/lib/extensions/trbe.h b/include/lib/extensions/trbe.h
index 0eff7c4..861a4ad 100644
--- a/include/lib/extensions/trbe.h
+++ b/include/lib/extensions/trbe.h
@@ -10,7 +10,7 @@
#if ENABLE_TRBE_FOR_NS
void trbe_enable(void);
#else
-void trbe_enable(void)
+static inline void trbe_enable(void)
{
}
#endif /* ENABLE_TRBE_FOR_NS */
diff --git a/include/lib/extensions/trf.h b/include/lib/extensions/trf.h
index a440abd..91a9615 100644
--- a/include/lib/extensions/trf.h
+++ b/include/lib/extensions/trf.h
@@ -10,7 +10,7 @@
#if ENABLE_TRF_FOR_NS
void trf_enable(void);
#else
-void trf_enable(void)
+static inline void trf_enable(void)
{
}
#endif /* ENABLE_TRF_FOR_NS */