Re: [PATCH v2] of/fdt: Fix #ifdef dependency of early flattree declarations
From: Rob Herring
Date: Fri Jan 05 2018 - 15:26:53 EST
On Thu, Jan 4, 2018 at 3:08 AM, Geert Uytterhoeven
<geert+renesas@xxxxxxxxx> wrote:
> If OF_FLATTREE=y, but OF_EARLY_FLATTREE=n:
>
> drivers/tty/serial/earlycon.o: In function `param_setup_earlycon':
> earlycon.c:(.init.text+0x3a4): undefined reference to `early_init_dt_scan_chosen_stdout'
>
> Fix this by moving the early flattree forward declarations and dummy
> implementations inside an #ifdef CONFIG_OF_EARLY_FLATTREE block.
>
> Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> ---
> Seen after forcing OF_FLATTREE=y on sparc64 allmodconfig
> (Hi, out-of-tree OF_CONFIGFS!).
>
> v2:
> - Move "#ifdef CONFIG_OF_EARLY_FLATTREE" section outside "#ifdef
> CONFIG_OF_FLATTREE" section to provide dummies if !OF_FLATTREE,
> - Move architecture-specific early_init_devtree() and
> early_get_first_memblock_info() inside "#ifdef
> CONFIG_OF_EARLY_FLATTREE" section.
> ---
> include/linux/of_fdt.h | 12 ++++++++----
> 1 file changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h
> index 013c5418aeecfdbd..444e6e283828a27e 100644
> --- a/include/linux/of_fdt.h
> +++ b/include/linux/of_fdt.h
> @@ -47,6 +47,12 @@ extern void *initial_boot_params;
> extern char __dtb_start[];
> extern char __dtb_end[];
>
> +/* Other Prototypes */
> +extern u64 of_flat_dt_translate_address(unsigned long node);
> +extern void of_fdt_limit_memory(int limit);
> +#endif /* CONFIG_OF_FLATTREE */
> +
> +#ifdef CONFIG_OF_EARLY_FLATTREE
> /* For scanning the flat device-tree at boot time */
> extern int of_scan_flat_dt(int (*it)(unsigned long node, const char *uname,
> int depth, void *data),
> @@ -97,16 +103,14 @@ extern void unflatten_device_tree(void);
> extern void unflatten_and_copy_device_tree(void);
> extern void early_init_devtree(void *);
> extern void early_get_first_memblock_info(void *, phys_addr_t *);
> -extern u64 of_flat_dt_translate_address(unsigned long node);
> -extern void of_fdt_limit_memory(int limit);
> -#else /* CONFIG_OF_FLATTREE */
> +#else /* CONFIG_OF_EARLY_FLATTREE */
> static inline int early_init_dt_scan_chosen_stdout(void) { return -ENODEV; }
> static inline void early_init_fdt_scan_reserved_mem(void) {}
> static inline void early_init_fdt_reserve_self(void) {}
> static inline const char *of_flat_dt_get_machine_name(void) { return NULL; }
> static inline void unflatten_device_tree(void) {}
> static inline void unflatten_and_copy_device_tree(void) {}
> -#endif /* CONFIG_OF_FLATTREE */
> +#endif /* CONFIG_OF_EARLY_FLATTREE */
Really, I think most of these shouldn't need dummy versions as they
are called from DT only code, but I guess we had some need to have
them. Ideally, we'd also remove some of these and avoid any arch
specific code, but looks like most do get used. I do see some further
memblock/bootmem clean-up we can do.
Anyway, it better than it was with your change, so I've applied it.
Rob