C++ ClearPageReserved函數代碼示例

static void vperfctr_free(struct vperfctr *perfctr)
{
	debug_free(perfctr);
	ClearPageReserved(virt_to_page(perfctr));
	free_page((unsigned long)perfctr);
	dec_nrctrs();
}

/**
 * Frees the physical pages allocated by the rtR0MemObjLinuxAllocPages() call.
 *
 * This method does NOT free the object.
 *
 * @param   pMemLnx     The object which physical pages should be freed.
 */
static void rtR0MemObjLinuxFreePages(PRTR0MEMOBJLNX pMemLnx)
{
    size_t iPage = pMemLnx->cPages;
    if (iPage > 0)
    {
        /*
         * Restore the page flags.
         */
        while (iPage-- > 0)
        {
            ClearPageReserved(pMemLnx->apPages[iPage]);
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 4, 22)
#else
            MY_SET_PAGES_NOEXEC(pMemLnx->apPages[iPage], 1);
#endif
        }

        /*
         * Free the pages.
         */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 4, 22)
        if (!pMemLnx->fContiguous)
        {
            iPage = pMemLnx->cPages;
            while (iPage-- > 0)
                __free_page(pMemLnx->apPages[iPage]);
        }
        else
#endif
            __free_pages(pMemLnx->apPages[0], rtR0MemObjLinuxOrder(pMemLnx->cPages));

        pMemLnx->cPages = 0;
    }
}

static int uninorth_free_gatt_table(void)
{
	int page_order;
	char *table, *table_end;
	void *temp;
	struct page *page;

	temp = agp_bridge->current_size;
	page_order = A_SIZE_32(temp)->page_order;

	/* Do not worry about freeing memory, because if this is
	 * called, then all agp memory is deallocated and removed
	 * from the table.
	 */

	table = (char *) agp_bridge->gatt_table_real;
	table_end = table + ((PAGE_SIZE * (1 << page_order)) - 1);

	for (page = virt_to_page(table); page <= virt_to_page(table_end); page++)
		ClearPageReserved(page);

	free_pages((unsigned long) agp_bridge->gatt_table_real, page_order);

	return 0;
}

void __init set_highmem_pages_init(void)
{
	struct zone *zone;
	int nid;

	for_each_zone(zone) {
		unsigned long zone_start_pfn, zone_end_pfn;

		if (!is_highmem(zone))
			continue;

		zone_start_pfn = zone->zone_start_pfn;
		zone_end_pfn = zone_start_pfn + zone->spanned_pages;

		nid = zone_to_nid(zone);
		printk(KERN_INFO "Initializing %s for node %d (%08lx:%08lx)\n",
				zone->name, nid, zone_start_pfn, zone_end_pfn);

		add_highpages_with_active_regions(nid, zone_start_pfn,
				 zone_end_pfn);

		/* XEN: init high-mem pages outside initial allocation. */
		if (zone_start_pfn < xen_start_info->nr_pages)
			zone_start_pfn = xen_start_info->nr_pages;
		for (; zone_start_pfn < zone_end_pfn; zone_start_pfn++) {
			ClearPageReserved(pfn_to_page(zone_start_pfn));
			init_page_count(pfn_to_page(zone_start_pfn));
		}
	}
	totalram_pages += totalhigh_pages;
}

void __init prom_free_prom_memory (void)
{
	unsigned long addr, end;

	/*
	 * Free everything below the kernel itself but leave
	 * the first page reserved for the exception handlers.
	 */

#if defined(CONFIG_DECLANCE) || defined(CONFIG_DECLANCE_MODULE)
	/*
	 * Leave 128 KB reserved for Lance memory for
	 * IOASIC DECstations.
	 *
	 * XXX: save this address for use in dec_lance.c?
	 */
	if (IOASIC)
		end = __pa(&_text) - 0x00020000;
	else
#endif
		end = __pa(&_text);

	addr = PAGE_SIZE;
	while (addr < end) {
		ClearPageReserved(virt_to_page(__va(addr)));
		set_page_count(virt_to_page(__va(addr)), 1);
		free_page((unsigned long)__va(addr));
		addr += PAGE_SIZE;
	}

	printk("Freeing unused PROM memory: %ldk freed\n",
	       (end - PAGE_SIZE) >> 10);
}

static int __init exemple_init (void)
{
	int err;
	struct page * pg = NULL;

	exemple_buffer = kmalloc(PAGE_SIZE, GFP_KERNEL);
	if (exemple_buffer == NULL)
		return -ENOMEM;

	exemple_buffer[0] = '\0';

	pg = virt_to_page(exemple_buffer);
	SetPageReserved(pg);

	err =  misc_register(& exemple_misc_driver);
	if (err != 0) {
		ClearPageReserved(pg);
		kfree(exemple_buffer);
		exemple_buffer = NULL;
		return err;
	}

#if LINUX_VERSION_CODE < KERNEL_VERSION(4,15,0)
	init_timer (& exemple_timer);
	exemple_timer.function = exemple_timer_function;
#else
	timer_setup (& exemple_timer, exemple_timer_function, 0);
#endif
	exemple_timer.expires = jiffies + HZ;
	add_timer(& exemple_timer);

	return 0;
}

static int device_release(struct inode *inode, struct file *filp){
    struct mmap_info *info=NULL;
    struct page *page=NULL;
	unsigned i=0;
	unsigned num_pages=0;

	pr_info("device_release: %d.%d\n", MAJOR (inode->i_rdev), MINOR (inode->i_rdev));

	IS_DONE_FLAG = 1;

	// Free RX buffer pointer queues
	info = filp->private_data;
	if (info->data ) {
		printk("[GNoM_km] on release: (%d) <%p>\n", info->reference_cnt, info->data);

		num_pages = (1<<K_PAGE_ORDER);

        for(i=0; i<num_pages; ++i){ // Unpin all of the the allocated pages
			page = virt_to_page((size_t)info->data + (i*CPU_PAGE_SIZE));
			if(PageReserved(page)){
                ClearPageReserved(page);
            }
		}

		free_pages((unsigned long)info->data, K_PAGE_ORDER); // Free 2^K_PAGE_ORDER pages
		kfree(info);
		filp->private_data = NULL;
    }

	printk("[GNoM_km]: %u mmaped Pages succesfully released\n", i);

	return 0;
}

void spu_free_lscsa(struct spu_state *csa)
{
	unsigned char *p;
	int i;

	if (!csa->use_big_pages) {
		spu_free_lscsa_std(csa);
		return;
	}
	csa->use_big_pages = 0;

	if (csa->lscsa == NULL)
		goto free_pages;

	for (p = csa->lscsa->ls; p < csa->lscsa->ls + LS_SIZE; p += PAGE_SIZE)
		ClearPageReserved(vmalloc_to_page(p));

	vunmap(csa->lscsa);
	csa->lscsa = NULL;

 free_pages:

	for (i = 0; i < SPU_LSCSA_NUM_BIG_PAGES; i++)
		if (csa->lscsa_pages[i])
			__free_pages(csa->lscsa_pages[i], SPU_64K_PAGE_ORDER);
}

static void ati_free_page_map(ati_page_map *page_map)
{
	unmap_page_from_agp(virt_to_page(page_map->real));
	iounmap(page_map->remapped);
	ClearPageReserved(virt_to_page(page_map->real));
	free_page((unsigned long) page_map->real);
}

/*
 * Free the memory-mapped buffer memory allocated for a
 * videobuf_buffer and the associated scatterlist.
 */
static void omap24xxcam_vbq_free_mmap_buffer(struct videobuf_buffer *vb)
{
	struct videobuf_dmabuf *dma = videobuf_to_dma(vb);
	size_t alloc_size;
	struct page *page;
	int i;

	if (dma->sglist == NULL)
		return;

	i = dma->sglen;
	while (i) {
		i--;
		alloc_size = sg_dma_len(&dma->sglist[i]);
		page = sg_page(&dma->sglist[i]);
		do {
			ClearPageReserved(page++);
		} while (alloc_size -= PAGE_SIZE);
		__free_pages(sg_page(&dma->sglist[i]),
			     get_order(sg_dma_len(&dma->sglist[i])));
	}

	kfree(dma->sglist);
	dma->sglist = NULL;
}

static void
dev_nvram_exit(void)
{
	int order = 0;
	struct page *page, *end;

	if (nvram_class) {
		class_device_destroy(nvram_class, MKDEV(nvram_major, 0));
		class_destroy(nvram_class);
	}

	if (nvram_major >= 0)
		unregister_chrdev(nvram_major, "nvram");

	if (nvram_mtd)
		put_mtd_device(nvram_mtd);

	while ((PAGE_SIZE << order) < nvram_space)
		order++;
	end = virt_to_page(nvram_buf + (PAGE_SIZE << order) - 1);
	for (page = virt_to_page(nvram_buf); page <= end; page++)
		ClearPageReserved(page);

	_nvram_exit();
}

/**
 * Frees memory allocated using RTMemContAlloc().
 *
 * @param   pv      Pointer to return from RTMemContAlloc().
 * @param   cb      The cb parameter passed to RTMemContAlloc().
 */
RTR0DECL(void) RTMemContFree(void *pv, size_t cb)
{
    if (pv)
    {
        int             cOrder;
        unsigned        cPages;
        unsigned        iPage;
        struct page    *paPages;

        /* validate */
        AssertMsg(!((uintptr_t)pv & PAGE_OFFSET_MASK), ("pv=%p\n", pv));
        Assert(cb > 0);

        /* calc order and get pages */
        cb = RT_ALIGN_Z(cb, PAGE_SIZE);
        cPages = cb >> PAGE_SHIFT;
        cOrder = CalcPowerOf2Order(cPages);
        paPages = virt_to_page(pv);

        /*
         * Restore page attributes freeing the pages.
         */
        for (iPage = 0; iPage < cPages; iPage++)
        {
            ClearPageReserved(&paPages[iPage]);
#if LINUX_VERSION_CODE > KERNEL_VERSION(2, 4, 20) /** @todo find the exact kernel where change_page_attr was introduced. */
            MY_SET_PAGES_NOEXEC(&paPages[iPage], 1);
#endif
        }
        __free_pages(paPages, cOrder);
    }
}

static int amd_create_page_map(struct amd_page_map *page_map)
{
	int i;

	page_map->real = (unsigned long *) __get_free_page(GFP_KERNEL);
	if (page_map->real == NULL)
		return -ENOMEM;

#ifndef CONFIG_X86
	SetPageReserved(virt_to_page(page_map->real));
	global_cache_flush();
	page_map->remapped = ioremap_nocache(virt_to_gart(page_map->real),
					    PAGE_SIZE);
	if (page_map->remapped == NULL) {
		ClearPageReserved(virt_to_page(page_map->real));
		free_page((unsigned long) page_map->real);
		page_map->real = NULL;
		return -ENOMEM;
	}
	global_cache_flush();
#else
	set_memory_uc((unsigned long)page_map->real, 1);
	page_map->remapped = page_map->real;
#endif

	for (i = 0; i < PAGE_SIZE / sizeof(unsigned long); i++) {
		writel(agp_bridge->scratch_page, page_map->remapped+i);
		readl(page_map->remapped+i);	/* PCI Posting. */
	}

	return 0;
}

static void Device1Exit(void)
{
  int i;
  UWORD *pTemp = (UWORD*)pUsbSpeed;

  dUsbExit();

  pUsbSpeed = &UsbSpeedDefault;

  for (i = 0; i < NPAGES * PAGE_SIZE; i+= PAGE_SIZE)
  {
    ClearPageReserved(virt_to_page(((unsigned long)pTemp) + i));

    //#define DEBUG
    #undef DEBUG
    #ifdef DEBUG
      printk("  %s memory page %d unmapped\n",DEVICE1_NAME,i);
    #endif
  }

  kfree(kmalloc_ptr);

  misc_deregister(&Device1);

  //#define DEBUG
  #undef DEBUG
  #ifdef DEBUG
    printk("  %s device unregistered\n",DEVICE1_NAME);
  #endif
}

static void
dev_nvram_exit(void)
{
	int order = 0;
	struct page *page, *end;

	if (nvram_class) {
#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 36)
		class_device_destroy(nvram_class, MKDEV(nvram_major, 0));
#else /* 2.6.36 and up */
		device_destroy(nvram_class, MKDEV(nvram_major, 0));
#endif
		class_destroy(nvram_class);
	}

	if (nvram_major >= 0)
		unregister_chrdev(nvram_major, "nvram");

	if (nvram_mtd)
		put_mtd_device(nvram_mtd);

	while ((PAGE_SIZE << order) < MAX_NVRAM_SPACE)
		order++;
	end = virt_to_page(nvram_buf + (PAGE_SIZE << order) - 1);
	for (page = virt_to_page(nvram_buf); page <= end; page++)
		ClearPageReserved(page);

	_nvram_exit();
}