Commit 86d0c164 authored by Christophe Leroy's avatar Christophe Leroy Committed by Linus Torvalds

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@csgroup.eu
Fixes: bbc180a5 ("mm: HUGE_VMAP arch support cleanup")
Signed-off-by: default avatarChristophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: default avatarNicholas Piggin <npiggin@gmail.com>
Reviewed-by: default avatarAnshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent f4d3f25a
...@@ -16,16 +16,16 @@ ...@@ -16,16 +16,16 @@
#include "pgalloc-track.h" #include "pgalloc-track.h"
#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP #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) static int __init set_nohugeiomap(char *str)
{ {
iomap_max_page_shift = P4D_SHIFT; iomap_max_page_shift = PAGE_SHIFT;
return 0; return 0;
} }
early_param("nohugeiomap", set_nohugeiomap); early_param("nohugeiomap", set_nohugeiomap);
#else /* CONFIG_HAVE_ARCH_HUGE_VMAP */ #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 */ #endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */
int ioremap_page_range(unsigned long addr, int ioremap_page_range(unsigned long addr,
......
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