From: Nathan Lynch <nath...@linux.ibm.com>

machine_is() can't provide correct results before probe_machine() has
run. Warn when it's used too early in boot.

Signed-off-by: Nathan Lynch <nath...@linux.ibm.com>
---
Prompted by my attempts to do some pseries-specific setup during
rtas_initialize() and being puzzled for a while that it wasn't
working.
---
 arch/powerpc/include/asm/machdep.h | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/include/asm/machdep.h 
b/arch/powerpc/include/asm/machdep.h
index 378b8d5836a7..8c0a799d18cd 100644
--- a/arch/powerpc/include/asm/machdep.h
+++ b/arch/powerpc/include/asm/machdep.h
@@ -220,11 +220,13 @@ extern struct machdep_calls *machine_id;
        EXPORT_SYMBOL(mach_##name);                             \
        struct machdep_calls mach_##name __machine_desc =
 
-#define machine_is(name) \
-       ({ \
-               extern struct machdep_calls mach_##name \
-                       __attribute__((weak));           \
-               machine_id == &mach_##name; \
+#define machine_is(name)                                            \
+       ({                                                          \
+               extern struct machdep_calls mach_##name             \
+                       __attribute__((weak));                      \
+               WARN(!machine_id,                                   \
+                    "machine_is() called before probe_machine()"); \
+               machine_id == &mach_##name;                         \
        })
 
 static inline void log_error(char *buf, unsigned int err_type, int fatal)

---
base-commit: 0bfb97203f5f300777624a2ad6f8f84aea3e8658
change-id: 20230210-warn-on-machine-is-before-probe-machine-37515b1f43bb

Best regards,
-- 
Nathan Lynch <nath...@linux.ibm.com>

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