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, placing the WARN_ON() in a helper function so the reported file:line indicates exactly what went wrong.
checkpatch complains about __attribute__((weak)) in the patch, so change that to __weak, and align the line continuations as well. 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. Changes in v2: - Use WARN_ON(), not WARN(). - Introduce __machine_is() helper function so the line reported is accurate. - Update __attribute__((weak)) to __weak for checkpatch's sake. - Link to v1: https://lore.kernel.org/r/20230210-warn-on-machine-is-before-probe-machine-v1-1-f0cba5712...@linux.ibm.com --- arch/powerpc/include/asm/machdep.h | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/arch/powerpc/include/asm/machdep.h b/arch/powerpc/include/asm/machdep.h index 378b8d5836a7..459736d5e511 100644 --- a/arch/powerpc/include/asm/machdep.h +++ b/arch/powerpc/include/asm/machdep.h @@ -3,6 +3,7 @@ #define _ASM_POWERPC_MACHDEP_H #ifdef __KERNEL__ +#include <linux/compiler.h> #include <linux/seq_file.h> #include <linux/init.h> #include <linux/dma-mapping.h> @@ -220,11 +221,16 @@ 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; \ +static inline bool __machine_is(const struct machdep_calls *md) +{ + WARN_ON(!machine_id); // complain if used before probe_machine() + return machine_id == md; +} + +#define machine_is(name) \ + ({ \ + extern struct machdep_calls mach_##name __weak; \ + __machine_is(&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>
