Re: [PATCH v2] powerpc32: memcpy/memset: only use dcbz once cache is enabled

On Thu, 2015-09-10 at 08:41 +0200, Christophe Leroy wrote:

 
+/* Cache related sections */
+#define BEGIN_CACHE_SECTION_NESTED(label)    START_FTR_SECTION(label)
+#define BEGIN_CACHE_SECTION                  START_FTR_SECTION(97)
+
+#define END_CACHE_SECTION_NESTED(msk, val, label)            \
+     FTR_SECTION_ELSE_NESTED(label)                          \
+     MAKE_FTR_SECTION_ENTRY(msk, val, label, __cache_fixup)
+
+#define END_CACHE_SECTION(msk, val)          \
+     END_CACHE_SECTION_NESTED(msk, val, 97)
+
+#define END_CACHE_SECTION_IFSET(msk) END_CACHE_SECTION((msk), (msk))
+#define END_CACHE_SECTION_IFCLR(msk) END_CACHE_SECTION((msk), 0)
+
+/* CACHE feature sections with alternatives, use BEGIN_FTR_SECTION to 
start */
+#define CACHE_SECTION_ELSE_NESTED(label)     FTR_SECTION_ELSE_NESTED(label)
+#define CACHE_SECTION_ELSE   CACHE_SECTION_ELSE_NESTED(97)
+#define ALT_CACHE_SECTION_END_NESTED(msk, val, label)        \
+     MAKE_FTR_SECTION_ENTRY(msk, val, label, __cache_fixup)
+#define ALT_CACHE_SECTION_END_NESTED_IFSET(msk, label)       \
+     ALT_CACHE_SECTION_END_NESTED(msk, msk, label)
+#define ALT_CACHE_SECTION_END_NESTED_IFCLR(msk, label)       \
+     ALT_CACHE_SECTION_END_NESTED(msk, 0, label)
+#define ALT_CACHE_SECTION_END(msk, val)      \
+     ALT_CACHE_SECTION_END_NESTED(msk, val, 97)
+#define ALT_CACHE_SECTION_END_IFSET(msk)     \
+     ALT_CACHE_SECTION_END_NESTED_IFSET(msk, 97)
+#define ALT_CACHE_SECTION_END_IFCLR(msk)     \
+     ALT_CACHE_SECTION_END_NESTED_IFCLR(msk, 97)

I don't think this duplication is what Michael meant by "the normal cpu 
feature sections".  What else is going to use this very specific 
infrastructure?

-Scott