C++ PageHighMem函数代码示例

void __flush_icache_page(struct vm_area_struct *vma, struct page *page)
{
	unsigned long addr;

	if (PageHighMem(page))
		return;

	addr = (unsigned long) page_address(page);
	flush_data_cache_page(addr);
}

void show_mem(unsigned int filter)
{
	pg_data_t *pgdat;
	unsigned long total = 0, reserved = 0, shared = 0,
		nonshared = 0, highmem = 0;

	printk("Mem-Info:\n");
	show_free_areas(filter);

	if (filter & SHOW_MEM_FILTER_PAGE_COUNT)
		return;

	for_each_online_pgdat(pgdat) {
		unsigned long i, flags;

		pgdat_resize_lock(pgdat, &flags);
		for (i = 0; i < pgdat->node_spanned_pages; i++) {
			struct page *page;
			unsigned long pfn = pgdat->node_start_pfn + i;

			if (unlikely(!(i % MAX_ORDER_NR_PAGES)))
				touch_nmi_watchdog();

			if (!pfn_valid(pfn))
				continue;

			page = pfn_to_page(pfn);

			if (PageHighMem(page))
				highmem++;

			if (PageReserved(page))
				reserved++;
			else if (page_count(page) == 1)
				nonshared++;
			else if (page_count(page) > 1)
				shared += page_count(page) - 1;

			total++;
		}
		pgdat_resize_unlock(pgdat, &flags);
	}

	printk("%lu pages RAM\n", total);
#ifdef CONFIG_HIGHMEM
	printk("%lu pages HighMem\n", highmem);
#endif
	printk("%lu pages reserved\n", reserved);
	printk("%lu pages shared\n", shared);
	printk("%lu pages non-shared\n", nonshared);
#ifdef CONFIG_QUICKLIST
	printk("%lu pages in pagetable cache\n",
		quicklist_total_size());
#endif
}

static inline void pgd_walk_set_prot(void *pt, pgprot_t flags)
{
	struct page *page = virt_to_page(pt);
	unsigned long pfn = page_to_pfn(page);

	if (PageHighMem(page))
		return;
	BUG_ON(HYPERVISOR_update_va_mapping(
		(unsigned long)__va(pfn << PAGE_SHIFT),
		pfn_pte(pfn, flags), 0));
}

static void dma_cache_maint_page(struct page *page, unsigned long offset,
	size_t size, enum dma_data_direction dir,
	void (*op)(const void *, size_t, int))
{
	/*
	 * A single sg entry may refer to multiple physically contiguous
	 * pages.  But we still need to process highmem pages individually.
	 * If highmem is not configured then the bulk of this loop gets
	 * optimized out.
	 */

	size_t left = size;
	do {
		size_t len = left;
		void *vaddr;

		if (PageHighMem(page)) {
			if (len + offset > PAGE_SIZE) {
				if (offset >= PAGE_SIZE) {
					page += offset / PAGE_SIZE;
					offset %= PAGE_SIZE;
				}
				len = PAGE_SIZE - offset;
			}
			vaddr = kmap_high_get(page);
			if (vaddr) {
				vaddr += offset;
				op(vaddr, len, dir);
				kunmap_high(page);
			} else if (cache_is_vipt()) {
				pte_t saved_pte;
				vaddr = kmap_high_l1_vipt(page, &saved_pte);
				if(vaddr) //TI
				{ //TI
				op(vaddr + offset, len, dir);
				kunmap_high_l1_vipt(page, saved_pte);
				}else //TI
					printk(KERN_ERR "SSN: 1 vaddr is NULL\n");//TI
			}
			else //TI
					printk(KERN_ERR "SSN: 2 vaddr is NULL\n"); //TI

		} else {
			vaddr = page_address(page) + offset;
			if(vaddr) //TI
				op(vaddr, len, dir);
			else //TI
				printk(KERN_ERR "SSN: 3 vaddr is NULL\n"); //TI
		}
		offset = 0;
		page++;
		left -= len;
	} while (left);
}

/* balloon_append: add the given page to the balloon. */
static void __balloon_append(struct page *page)
{
	/* Lowmem is re-populated first, so highmem pages go at list tail. */
	if (PageHighMem(page)) {
		list_add_tail(&page->lru, &ballooned_pages);
		balloon_stats.balloon_high++;
	} else {
		list_add(&page->lru, &ballooned_pages);
		balloon_stats.balloon_low++;
	}
}

static inline void *coherent_kvaddr(struct page *page, unsigned long base,
				    unsigned long vaddr, unsigned long *paddr)
{
	if (PageHighMem(page) || !DCACHE_ALIAS_EQ(page_to_phys(page), vaddr)) {
		*paddr = page_to_phys(page);
		return (void *)(base + (vaddr & DCACHE_ALIAS_MASK));
	} else {
		*paddr = 0;
		return page_to_virt(page);
	}
}

void __flush_dcache_page(struct page *page)
{
#ifdef CONFIG_RALINK_SOC
	void *addr;

	if (page_mapping(page) && !page_mapped(page)) {
		SetPageDcacheDirty(page);
		return;
	}
#else
	struct address_space *mapping = page_mapping(page);
	unsigned long addr;

	if (PageHighMem(page))
		return;
	if (mapping && !mapping_mapped(mapping)) {
		SetPageDcacheDirty(page);
		return;
	}
#endif

	/*
	 * We could delay the flush for the !page_mapping case too.  But that
	 * case is for exec env/arg pages and those are %99 certainly going to
	 * get faulted into the tlb (and thus flushed) anyways.
	 */
#ifdef CONFIG_RALINK_SOC
	if (PageHighMem(page)) {
		addr = kmap_atomic(page, KM_PTE1);
		flush_data_cache_page((unsigned long)addr);
		kunmap_atomic(addr, KM_PTE1);
	} else {
		addr = (void *) page_address(page);
		flush_data_cache_page((unsigned long)addr);
	}
	ClearPageDcacheDirty(page);
#else
	addr = (unsigned long) page_address(page);
	flush_data_cache_page(addr);
#endif
}

struct scatterlist*
videobuf_pages_to_sg(struct page **pages, int nr_pages, int offset)
{
	struct scatterlist *sglist;
	int i = 0;

	if (NULL == pages[0])
		return NULL;
	sglist = kmalloc(sizeof(*sglist) * nr_pages, GFP_KERNEL);
	if (NULL == sglist)
		return NULL;
	memset(sglist, 0, sizeof(*sglist) * nr_pages);

	if (NULL == pages[0])
		goto nopage;
	if (PageHighMem(pages[0]))
		/* DMA to highmem pages might not work */
		goto highmem;
	sglist[0].page   = pages[0];
	sglist[0].offset = offset;
	sglist[0].length = PAGE_SIZE - offset;
	for (i = 1; i < nr_pages; i++) {
		if (NULL == pages[i])
			goto nopage;
		if (PageHighMem(pages[i]))
			goto highmem;
		sglist[i].page   = pages[i];
		sglist[i].length = PAGE_SIZE;
	}
	return sglist;

 nopage:
	dprintk(2,"sgl: oops - no page\n");
	kfree(sglist);
	return NULL;

 highmem:
	dprintk(2,"sgl: oops - highmem page\n");
	kfree(sglist);
	return NULL;
}

void *__kmap(struct page *page)
{
	void *addr;

	might_sleep();
	if (!PageHighMem(page))
		return page_address(page);
	addr = kmap_high(page);
	flush_tlb_one((unsigned long)addr);

	return addr;
}

static void *try_ram_remap(resource_size_t offset, size_t size,
			   unsigned long flags)
{
	unsigned long pfn = PHYS_PFN(offset);

	/* In the simple case just return the existing linear address */
	if (pfn_valid(pfn) && !PageHighMem(pfn_to_page(pfn)) &&
	    arch_memremap_can_ram_remap(offset, size, flags))
		return __va(offset);

	return NULL; /* fallback to arch_memremap_wb */
}

static struct aead_request *crypto_rfc4543_crypt(struct aead_request *req,
						 int enc)
{
	struct crypto_aead *aead = crypto_aead_reqtfm(req);
	struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(aead);
	struct crypto_rfc4543_req_ctx *rctx = crypto_rfc4543_reqctx(req);
	struct aead_request *subreq = &rctx->subreq;
	struct scatterlist *dst = req->dst;
	struct scatterlist *cipher = rctx->cipher;
	struct scatterlist *payload = rctx->payload;
	struct scatterlist *assoc = rctx->assoc;
	unsigned int authsize = crypto_aead_authsize(aead);
	unsigned int assoclen = req->assoclen;
	struct page *dstp;
	u8 *vdst;
	u8 *iv = PTR_ALIGN((u8 *)(rctx + 1) + crypto_aead_reqsize(ctx->child),
			   crypto_aead_alignmask(ctx->child) + 1);

	memcpy(iv, ctx->nonce, 4);
	memcpy(iv + 4, req->iv, 8);

	/* construct cipher/plaintext */
	if (enc)
		memset(rctx->auth_tag, 0, authsize);
	else
		scatterwalk_map_and_copy(rctx->auth_tag, dst,
					 req->cryptlen - authsize,
					 authsize, 0);

	sg_init_one(cipher, rctx->auth_tag, authsize);

	/* construct the aad */
	dstp = sg_page(dst);
	vdst = PageHighMem(dstp) ? NULL : page_address(dstp) + dst->offset;

	sg_init_table(payload, 2);
	sg_set_buf(payload, req->iv, 8);
	scatterwalk_crypto_chain(payload, dst, vdst == req->iv + 8, 2);
	assoclen += 8 + req->cryptlen - (enc ? 0 : authsize);

	sg_init_table(assoc, 2);
	sg_set_page(assoc, sg_page(req->assoc), req->assoc->length,
		    req->assoc->offset);
	scatterwalk_crypto_chain(assoc, payload, 0, 2);

	aead_request_set_tfm(subreq, ctx->child);
	aead_request_set_callback(subreq, req->base.flags, req->base.complete,
				  req->base.data);
	aead_request_set_crypt(subreq, cipher, cipher, enc ? 0 : authsize, iv);
	aead_request_set_assoc(subreq, assoc, assoclen);

	return subreq;
}

void *os_kmap_sgptr(PSG psg)
{
	struct page * page = (struct page *)(HPT_UPTR)(psg->addr.bus>>32);

	if (page)
		return (PageHighMem(page)?
				(char *)kmap_atomic(page) :
				(char *)page_address(page))
			+ (psg->addr.bus & 0xffffffff);
	else
		return psg->addr._logical;
}

static void poison_page(struct page *page)
{
	void *addr;

	if (PageHighMem(page)) {
		poison_highpage(page);
		return;
	}
	set_page_poison(page);
	addr = page_address(page);
	memset(addr, PAGE_POISON, PAGE_SIZE);
}

static void __dma_remap(struct page *page, size_t size, pgprot_t prot)
{
	unsigned long start = (unsigned long) page_address(page);
	unsigned end = start + size;

	if (PageHighMem(page))
		return;
	apply_to_page_range(&init_mm, start,
		size, __dma_update_pte, &prot);
	dsb();
	flush_tlb_kernel_range(start, end);
}

void __flush_anon_page(struct page *page, unsigned long vmaddr)
{
#ifdef CONFIG_RALINK_SOC
	if (!PageHighMem(page)) {
		unsigned long addr = (unsigned long) page_address(page);

		if (pages_do_alias(addr, vmaddr & PAGE_MASK)) {
			if (page_mapped(page) && !Page_dcache_dirty(page)) {
				void *kaddr;

				kaddr = kmap_coherent(page, vmaddr);
				flush_data_cache_page((unsigned long)kaddr);
				kunmap_coherent();
			} else {
				flush_data_cache_page(addr);
				ClearPageDcacheDirty(page);
			}
		}
	} else {
		void *laddr = lowmem_page_address(page);

		if (pages_do_alias((unsigned long)laddr, vmaddr & PAGE_MASK)) {
			if (page_mapped(page) && !Page_dcache_dirty(page)) {
				void *kaddr;

				kaddr = kmap_coherent(page, vmaddr);
				flush_data_cache_page((unsigned long)kaddr);
				kunmap_coherent();
			} else {
				void *kaddr;

				kaddr = kmap_atomic(page, KM_PTE1);
				flush_data_cache_page((unsigned long)kaddr);
				kunmap_atomic(kaddr, KM_PTE1);
				ClearPageDcacheDirty(page);
			}
		}
	}
#else
	unsigned long addr = (unsigned long) page_address(page);

	if (pages_do_alias(addr, vmaddr)) {
		if (page_mapped(page) && !Page_dcache_dirty(page)) {
			void *kaddr;

			kaddr = kmap_coherent(page, vmaddr);
			flush_data_cache_page((unsigned long)kaddr);
			kunmap_coherent();
		} else
			flush_data_cache_page(addr);
	}
#endif
}