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authorAnshuman Khandual <anshuman.khandual@arm.com>2019-07-16 16:27:33 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-07-16 19:23:22 -0700
commit0f472d04f59ff89d15b2a1c4eafde7317ddd67a2 (patch)
tree20786684171109ec50859a88c6a354e12e2a8390 /lib
parent6b95ab4218bfa59bc315105127ffe03aef3b5742 (diff)
downloadlinux-0f472d04f59ff89d15b2a1c4eafde7317ddd67a2.tar.gz
mm/ioremap: probe platform for p4d huge map support
Finish up what commit c2febafc6773 ("mm: convert generic code to 5-level
paging") started while levelling up P4D huge mapping support at par with
PUD and PMD.  A new arch call back arch_ioremap_p4d_supported() is added
which just maintains status quo (P4D huge map not supported) on x86,
arm64 and powerpc.

When HAVE_ARCH_HUGE_VMAP is enabled its just a simple check from the
arch about the support, hence runtime effects are minimal.

Link: http://lkml.kernel.org/r/1561699231-20991-1-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib')
-rw-r--r--lib/ioremap.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/lib/ioremap.c b/lib/ioremap.c
index a95161d9c883..0a2ffadc6d71 100644
--- a/lib/ioremap.c
+++ b/lib/ioremap.c
@@ -30,6 +30,8 @@ early_param("nohugeiomap", set_nohugeiomap);
 void __init ioremap_huge_init(void)
 {
 	if (!ioremap_huge_disabled) {
+		if (arch_ioremap_p4d_supported())
+			ioremap_p4d_capable = 1;
 		if (arch_ioremap_pud_supported())
 			ioremap_pud_capable = 1;
 		if (arch_ioremap_pmd_supported())