C++ slab_is_available函数代码示例

static int __init_refok init_section_page_cgroup(unsigned long pfn, int nid)
{
	struct page_cgroup *base, *pc;
	struct mem_section *section;
	unsigned long table_size;
	unsigned long nr;
	int index;

	nr = pfn_to_section_nr(pfn);
	section = __nr_to_section(nr);

	if (section->page_cgroup)
		return 0;

	table_size = sizeof(struct page_cgroup) * PAGES_PER_SECTION;
	VM_BUG_ON(!slab_is_available());
	base = alloc_page_cgroup(table_size, nid);
	if (!base) {
		printk(KERN_ERR "page cgroup allocation failure\n");
		return -ENOMEM;
	}

	for (index = 0; index < PAGES_PER_SECTION; index++) {
		pc = base + index;
		init_page_cgroup(pc, nr);
	}
	/*
	 * The passed "pfn" may not be aligned to SECTION.  For the calculation
	 * we need to apply a mask.
	 */
	pfn &= PAGE_SECTION_MASK;
	section->page_cgroup = base - pfn;
	total_usage += table_size;
	return 0;
}

static void * __ref alloc_p2m_page(void)
{
	if (unlikely(!slab_is_available()))
		return alloc_bootmem_align(PAGE_SIZE, PAGE_SIZE);

	return (void *)__get_free_page(GFP_KERNEL | __GFP_REPEAT);
}

/**
 * __alloc_bootmem_node - allocate boot memory from a specific node
 * @pgdat: node to allocate from
 * @size: size of the request in bytes
 * @align: alignment of the region
 * @goal: preferred starting address of the region
 *
 * The goal is dropped if it can not be satisfied and the allocation will
 * fall back to memory below @goal.
 *
 * Allocation may fall back to any node in the system if the specified node
 * can not hold the requested memory.
 *
 * The function panics if the request can not be satisfied.
 */
void * __init __alloc_bootmem_node(pg_data_t *pgdat, unsigned long size,
				   unsigned long align, unsigned long goal)
{
	BUG_ON(slab_is_available());

	return ___alloc_bootmem_node(pgdat, size, align, goal, 0);
}

int __ref msi_bitmap_alloc(struct msi_bitmap *bmp, unsigned int irq_count,
		     struct device_node *of_node)
{
	int size;

	if (!irq_count)
		return -EINVAL;

	size = BITS_TO_LONGS(irq_count) * sizeof(long);
	pr_debug("msi_bitmap: allocator bitmap size is 0x%x bytes\n", size);

	bmp->bitmap_from_slab = slab_is_available();
	if (bmp->bitmap_from_slab)
		bmp->bitmap = kzalloc(size, GFP_KERNEL);
	else {
		bmp->bitmap = memblock_virt_alloc(size, 0);
		/* the bitmap won't be freed from memblock allocator */
		kmemleak_not_leak(bmp->bitmap);
	}

	if (!bmp->bitmap) {
		pr_debug("msi_bitmap: ENOMEM allocating allocator bitmap!\n");
		return -ENOMEM;
	}

	/* We zalloc'ed the bitmap, so all irqs are free by default */
	spin_lock_init(&bmp->lock);
	bmp->of_node = of_node_get(of_node);
	bmp->irq_count = irq_count;

	return 0;
}

/**
 * __alloc_bootmem_node - allocate boot memory from a specific node
 * @pgdat: node to allocate from
 * @size: size of the request in bytes
 * @align: alignment of the region
 * @goal: preferred starting address of the region
 *
 * The goal is dropped if it can not be satisfied and the allocation will
 * fall back to memory below @goal.
 *
 * Allocation may fall back to any node in the system if the specified node
 * can not hold the requested memory.
 *
 * The function panics if the request can not be satisfied.
 */
void * __init __alloc_bootmem_node(pg_data_t *pgdat, unsigned long size,
				   unsigned long align, unsigned long goal)
{
	if (WARN_ON_ONCE(slab_is_available()))
		return kzalloc_node(size, GFP_NOWAIT, pgdat->node_id);

	return ___alloc_bootmem_node(pgdat, size, align, goal, 0);
}

void __mf_check(void *ptr, unsigned int sz, int type, const char *location)
{
	if (!slab_is_available())
		return;
	if (verify_ptr((unsigned long)ptr))
		return;
	if (type) /* write */
		slab_check_write(ptr, sz, location);
}

static void __ref free_p2m_page(void *p)
{
	if (unlikely(!slab_is_available())) {
		free_bootmem((unsigned long)p, PAGE_SIZE);
		return;
	}

	free_page((unsigned long)p);
}

static void alloc_init_pmd(pud_t *pud, unsigned long addr, unsigned long end,
				  phys_addr_t phys, pgprot_t prot,
				  phys_addr_t (*pgtable_alloc)(void))
{
	pmd_t *pmd;
	unsigned long next;

	/*
	 * Check for initial section mappings in the pgd/pud and remove them.
	 */
	if (pud_none(*pud) || pud_sect(*pud)) {
		phys_addr_t pmd_phys;
		BUG_ON(!pgtable_alloc);
		pmd_phys = pgtable_alloc();
		pmd = pmd_set_fixmap(pmd_phys);
		if (pud_sect(*pud)) {
			/*
			 * need to have the 1G of mappings continue to be
			 * present
			 */
			split_pud(pud, pmd);
		}
		__pud_populate(pud, pmd_phys, PUD_TYPE_TABLE);
		flush_tlb_all();
		pmd_clear_fixmap();
	}
	BUG_ON(pud_bad(*pud));

	pmd = pmd_set_fixmap_offset(pud, addr);
	do {
		next = pmd_addr_end(addr, end);
		/* try section mapping first */
		if (((addr | next | phys) & ~SECTION_MASK) == 0 &&
		      block_mappings_allowed(pgtable_alloc)) {
			pmd_t old_pmd =*pmd;
			pmd_set_huge(pmd, phys, prot);
			/*
			 * Check for previous table entries created during
			 * boot (__create_page_tables) and flush them.
			 */
			if (!pmd_none(old_pmd)) {
				flush_tlb_all();
				if (pmd_table(old_pmd)) {
					phys_addr_t table = pmd_page_paddr(old_pmd);
					if (!WARN_ON_ONCE(slab_is_available()))
						memblock_free(table, PAGE_SIZE);
				}
			}
		} else {
			alloc_init_pte(pmd, addr, next, __phys_to_pfn(phys),
				       prot, pgtable_alloc);
		}
		phys += next - addr;
	} while (pmd++, addr = next, addr != end);

	pmd_clear_fixmap();
}

void * __ref zalloc_maybe_bootmem(size_t size, gfp_t mask)
{
	void *p;

	if (slab_is_available())
		p = kzalloc(size, mask);
	else {
		p = memblock_virt_alloc(size, 0);
	}
	return p;
}

static void alloc_init_pmd(struct mm_struct *mm, pud_t *pud,
				  unsigned long addr, unsigned long end,
				  phys_addr_t phys, pgprot_t prot,
				  void *(*alloc)(unsigned long size))
{
	pmd_t *pmd;
	unsigned long next;

	/*
	 * Check for initial section mappings in the pgd/pud and remove them.
	 */
	if (pud_none(*pud) || pud_sect(*pud)) {
		pmd = alloc(PTRS_PER_PMD * sizeof(pmd_t));
		if (pud_sect(*pud)) {
			/*
			 * need to have the 1G of mappings continue to be
			 * present
			 */
			split_pud(pud, pmd);
		}
		pud_populate(mm, pud, pmd);
		flush_tlb_all();
	}
	BUG_ON(pud_bad(*pud));

	pmd = pmd_offset(pud, addr);
	do {
		next = pmd_addr_end(addr, end);
		/* try section mapping first */
		if (((addr | next | phys) & ~SECTION_MASK) == 0) {
			pmd_t old_pmd =*pmd;
			set_pmd(pmd, __pmd(phys |
					   pgprot_val(mk_sect_prot(prot))));
			/*
			 * Check for previous table entries created during
			 * boot (__create_page_tables) and flush them.
			 */
			if (!pmd_none(old_pmd)) {
				flush_tlb_all();
				if (pmd_table(old_pmd)) {
					phys_addr_t table = __pa(pte_offset_map(&old_pmd, 0));
					if (!WARN_ON_ONCE(slab_is_available()))
						memblock_free(table, PAGE_SIZE);
				}
			}
		} else {
			alloc_init_pte(pmd, addr, next, __phys_to_pfn(phys),
				       prot, alloc);
		}
		phys += next - addr;
	} while (pmd++, addr = next, addr != end);
}

void * __meminit vmemmap_alloc_block(unsigned long size, int node)
{
	/* If the main allocator is up use that, fallback to bootmem. */
	if (slab_is_available()) {
		struct page *page = alloc_pages_node(node,
				GFP_KERNEL | __GFP_ZERO, get_order(size));
		if (page)
			return page_address(page);
		return NULL;
	} else
		return __earlyonly_bootmem_alloc(node, size, size,
				__pa(MAX_DMA_ADDRESS));
}

__ref pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
{
	pte_t *pte;

	if (slab_is_available()) {
		pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_ZERO);
	} else {
		pte = __va(memblock_alloc(PAGE_SIZE, PAGE_SIZE));
		if (pte)
			clear_page(pte);
	}
	return pte;
}

static void alloc_init_pud(pgd_t *pgd, unsigned long addr, unsigned long end,
				  phys_addr_t phys, pgprot_t prot,
				  phys_addr_t (*pgtable_alloc)(void))
{
	pud_t *pud;
	unsigned long next;

	if (pgd_none(*pgd)) {
		phys_addr_t pud_phys;
		BUG_ON(!pgtable_alloc);
		pud_phys = pgtable_alloc();
		__pgd_populate(pgd, pud_phys, PUD_TYPE_TABLE);
	}
	BUG_ON(pgd_bad(*pgd));

	pud = pud_set_fixmap_offset(pgd, addr);
	do {
		next = pud_addr_end(addr, end);

		/*
		 * For 4K granule only, attempt to put down a 1GB block
		 */
		if (use_1G_block(addr, next, phys) &&
		    block_mappings_allowed(pgtable_alloc)) {
			pud_t old_pud = *pud;
			pud_set_huge(pud, phys, prot);

			/*
			 * If we have an old value for a pud, it will
			 * be pointing to a pmd table that we no longer
			 * need (from swapper_pg_dir).
			 *
			 * Look up the old pmd table and free it.
			 */
			if (!pud_none(old_pud)) {
				flush_tlb_all();
				if (pud_table(old_pud)) {
					phys_addr_t table = pud_page_paddr(old_pud);
					if (!WARN_ON_ONCE(slab_is_available()))
						memblock_free(table, PAGE_SIZE);
				}
			}
		} else {
			alloc_init_pmd(pud, addr, next, phys, prot,
				       pgtable_alloc);
		}
		phys += next - addr;
	} while (pud++, addr = next, addr != end);

	pud_clear_fixmap();
}

static __init_refok void *sh64_get_page(void)
{
	void *page;

	if (slab_is_available())
		page = (void *)get_zeroed_page(GFP_KERNEL);
	else
		page = alloc_bootmem_pages(PAGE_SIZE);

	if (!page || ((unsigned long)page & ~PAGE_MASK))
		panic("sh64_get_page: Out of memory already?\n");

	return page;
}

static pte_t __ref *vmem_pte_alloc(void)
{
	pte_t *pte;

	if (slab_is_available())
		pte = (pte_t *) page_table_alloc(&init_mm);
	else
		pte = alloc_bootmem(PTRS_PER_PTE * sizeof(pte_t));
	if (!pte)
		return NULL;
	clear_table((unsigned long *) pte, _PAGE_TYPE_EMPTY,
		    PTRS_PER_PTE * sizeof(pte_t));
	return pte;
}