From: Christophe Leroy <christophe.leroy@xxxxxxxxxx> Subject: mm/ioremap: fix iomap_max_page_shift iomap_max_page_shift is expected to contain a page shift, so it can't be a 'bool', has to be an 'unsigned int' And fix the default values: P4D_SHIFT is when huge iomap is allowed. However, on some architectures (eg: powerpc book3s/64), P4D_SHIFT is not a constant so it can't be used to initialise a static variable. So, initialise iomap_max_page_shift with a maximum shift supported by the architecture, it is gated by P4D_SHIFT in vmap_try_huge_p4d() anyway. Link: https://lkml.kernel.org/r/ad2d366015794a9f21320dcbdd0a8eb98979e9df.1620898113.git.christophe.leroy@xxxxxxxxxx Fixes: bbc180a5adb0 ("mm: HUGE_VMAP arch support cleanup") Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx> Reviewed-by: Nicholas Piggin <npiggin@xxxxxxxxx> Reviewed-by: Anshuman Khandual <anshuman.khandual@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/ioremap.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/mm/ioremap.c~mm-ioremap-fix-iomap_max_page_shift +++ a/mm/ioremap.c @@ -16,16 +16,16 @@ #include "pgalloc-track.h" #ifdef CONFIG_HAVE_ARCH_HUGE_VMAP -static bool __ro_after_init iomap_max_page_shift = PAGE_SHIFT; +static unsigned int __ro_after_init iomap_max_page_shift = BITS_PER_LONG - 1; static int __init set_nohugeiomap(char *str) { - iomap_max_page_shift = P4D_SHIFT; + iomap_max_page_shift = PAGE_SHIFT; return 0; } early_param("nohugeiomap", set_nohugeiomap); #else /* CONFIG_HAVE_ARCH_HUGE_VMAP */ -static const bool iomap_max_page_shift = PAGE_SHIFT; +static const unsigned int iomap_max_page_shift = PAGE_SHIFT; #endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */ int ioremap_page_range(unsigned long addr, _
