mm/ioremap: probe platform for p4d huge map support (0f472d04) · Commits · 戴 / test

Finish up what commit ("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>

arch/arm64/mm/mmu.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -942,6 +942,11 @@ void *__init fixmap_remap_fdt(phys_addr_t dt_phys)
		return dt_virt;
		}

		int __init arch_ioremap_p4d_supported(void)
		{
		return 0;
		}

		int __init arch_ioremap_pud_supported(void)
		{
		/*

arch/powerpc/mm/book3s64/radix_pgtable.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -1237,3 +1237,8 @@ int radix__ioremap_range(unsigned long ea, phys_addr_t pa, unsigned long size,
		return 0;
		}
		}

		int __init arch_ioremap_p4d_supported(void)
		{
		return 0;
		}

arch/x86/mm/ioremap.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -459,6 +459,11 @@ void iounmap(volatile void __iomem *addr)
		}
		EXPORT_SYMBOL(iounmap);

		int __init arch_ioremap_p4d_supported(void)
		{
		return 0;
		}

		int __init arch_ioremap_pud_supported(void)
		{
		#ifdef CONFIG_X86_64

include/linux/io.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -33,6 +33,7 @@ static inline int ioremap_page_range(unsigned long addr, unsigned long end,

		#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
		void __init ioremap_huge_init(void);
		int arch_ioremap_p4d_supported(void);
		int arch_ioremap_pud_supported(void);
		int arch_ioremap_pmd_supported(void);
		#else

lib/ioremap.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -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())

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