I found this when compiling a kbuild random config with GCC 11. The
config enables CONFIG_DEBUG_SECTION_MISMATCH, which sets CFLAGS
-fno-inline-functions-called-once. This causes the call to cache_loop in
cache.c to not be inlined causing the below compile error.
In file included from arch/openrisc/mm/cache.c:13:
arch/openrisc/mm/cache.c: In function 'cache_loop':
./arch/openrisc/include/asm/spr.h:16:27: warning: 'asm' operand 0 probably
does not match constraints
16 | #define mtspr(_spr, _val) __asm__ __volatile__ ( \
| ^~~~~~~
arch/openrisc/mm/cache.c:25:3: note: in expansion of macro 'mtspr'
25 | mtspr(reg, line);
| ^~~~~
./arch/openrisc/include/asm/spr.h:16:27: error: impossible constraint in
'asm'
16 | #define mtspr(_spr, _val) __asm__ __volatile__ ( \
| ^~~~~~~
arch/openrisc/mm/cache.c:25:3: note: in expansion of macro 'mtspr'
25 | mtspr(reg, line);
| ^~~~~
make[1]: *** [scripts/Makefile.build:283: arch/openrisc/mm/cache.o] Error 1
The asm constraint "K" requires a immediate constant argument to mtspr,
however because of no inlining a register argument is passed causing a
failure. Fix this by using __always_inline.
Link: https://lore.kernel.org/lkml/202008200453.ohnhqkjq%25...@intel.com/
Signed-off-by: Stafford Horne <sho...@gmail.com>
---
arch/openrisc/mm/cache.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/openrisc/mm/cache.c b/arch/openrisc/mm/cache.c
index 08f56af387ac..534a52ec5e66 100644
--- a/arch/openrisc/mm/cache.c
+++ b/arch/openrisc/mm/cache.c
@@ -16,7 +16,7 @@
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
-static void cache_loop(struct page *page, const unsigned int reg)
+static __always_inline void cache_loop(struct page *page, const unsigned int
reg)
{
unsigned long paddr = page_to_pfn(page) << PAGE_SHIFT;
unsigned long line = paddr & ~(L1_CACHE_BYTES - 1);
--
2.26.2
