ppc64: SPARSEMEM_VMEMMAP support (d29eff7b) · Commits · 戴 / test

arch/powerpc/Kconfig

+1 −0

Original line number	Diff line number	Diff line
		@@ -295,6 +295,7 @@ config ARCH_FLATMEM_ENABLE
		config ARCH_SPARSEMEM_ENABLE
		def_bool y
		depends on PPC64
		select SPARSEMEM_VMEMMAP_ENABLE

		config ARCH_SPARSEMEM_DEFAULT
		def_bool y

arch/powerpc/mm/init_64.c

+67 −0

Original line number	Diff line number	Diff line
		@@ -183,3 +183,70 @@ void pgtable_cache_init(void)
		zero_ctor);
		}
		}

		#ifdef CONFIG_SPARSEMEM_VMEMMAP
		/*
		* Given an address within the vmemmap, determine the pfn of the page that
		* represents the start of the section it is within. Note that we have to
		* do this by hand as the proffered address may not be correctly aligned.
		* Subtraction of non-aligned pointers produces undefined results.
		*/
		unsigned long __meminit vmemmap_section_start(unsigned long page)
		{
		unsigned long offset = page - ((unsigned long)(vmemmap));

		/* Return the pfn of the start of the section. */
		return (offset / sizeof(struct page)) & PAGE_SECTION_MASK;
		}

		/*
		* Check if this vmemmap page is already initialised. If any section
		* which overlaps this vmemmap page is initialised then this page is
		* initialised already.
		*/
		int __meminit vmemmap_populated(unsigned long start, int page_size)
		{
		unsigned long end = start + page_size;

		for (; start < end; start += (PAGES_PER_SECTION * sizeof(struct page)))
		if (pfn_valid(vmemmap_section_start(start)))
		return 1;

		return 0;
		}

		int __meminit vmemmap_populate(struct page *start_page,
		unsigned long nr_pages, int node)
		{
		unsigned long mode_rw;
		unsigned long start = (unsigned long)start_page;
		unsigned long end = (unsigned long)(start_page + nr_pages);
		unsigned long page_size = 1 << mmu_psize_defs[mmu_linear_psize].shift;

		mode_rw = _PAGE_ACCESSED \| _PAGE_DIRTY \| _PAGE_COHERENT \| PP_RWXX;

		/* Align to the page size of the linear mapping. */
		start = _ALIGN_DOWN(start, page_size);

		for (; start < end; start += page_size) {
		int mapped;
		void *p;

		if (vmemmap_populated(start, page_size))
		continue;

		p = vmemmap_alloc_block(page_size, node);
		if (!p)
		return -ENOMEM;

		printk(KERN_WARNING "vmemmap %08lx allocated at %p, "
		"physical %p.\n", start, p, __pa(p));

		mapped = htab_bolt_mapping(start, start + page_size,
		__pa(p), mode_rw, mmu_linear_psize);
		BUG_ON(mapped < 0);
		}

		return 0;
		}
		#endif

include/asm-powerpc/pgtable-ppc64.h

+8 −0

Original line number	Diff line number	Diff line
		@@ -67,6 +67,14 @@
		#define KERNEL_REGION_ID (REGION_ID(PAGE_OFFSET))
		#define USER_REGION_ID (0UL)

		/*
		* Defines the address of the vmemap area, in the top 16th of the
		* kernel region.
		*/
		#define VMEMMAP_BASE (ASM_CONST(CONFIG_KERNEL_START) + \
		(0xfUL << (REGION_SHIFT - 4)))
		#define vmemmap ((struct page *)VMEMMAP_BASE)

		/*
		* Common bits in a linux-style PTE. These match the bits in the
		* (hardware-defined) PowerPC PTE as closely as possible. Additional

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