arch/s390/mm/vmem.c - LeafOS-Devices/android_kernel_samsung_exynos9820 - Gitiles

 /*
  *  arch/s390/mm/vmem.c
  *
  *    Copyright IBM Corp. 2006
  *    Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
  */

 #include <linux/bootmem.h>
 #include <linux/pfn.h>
 #include <linux/mm.h>
 #include <linux/module.h>
 #include <linux/list.h>
 #include <asm/pgalloc.h>
 #include <asm/pgtable.h>
 #include <asm/setup.h>
 #include <asm/tlbflush.h>

 unsigned long vmalloc_end;
 EXPORT_SYMBOL(vmalloc_end);

 static struct page *vmem_map;
 static DEFINE_MUTEX(vmem_mutex);

 struct memory_segment {
 	struct list_head list;
 	unsigned long start;
 	unsigned long size;
 };

 static LIST_HEAD(mem_segs);

 void __meminit memmap_init(unsigned long size, int nid, unsigned long zone,
 			   unsigned long start_pfn)
 {
 	struct page *start, *end;
 	struct page *map_start, *map_end;
 	int i;

 	start = pfn_to_page(start_pfn);
 	end = start + size;

 	for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++) {
 		unsigned long cstart, cend;

 		cstart = PFN_DOWN(memory_chunk[i].addr);
 		cend = cstart + PFN_DOWN(memory_chunk[i].size);

 		map_start = mem_map + cstart;
 		map_end = mem_map + cend;

 		if (map_start < start)
 			map_start = start;
 		if (map_end > end)
 			map_end = end;

 		map_start -= ((unsigned long) map_start & (PAGE_SIZE - 1))
 			/ sizeof(struct page);
 		map_end += ((PFN_ALIGN((unsigned long) map_end)
 			     - (unsigned long) map_end)
 			    / sizeof(struct page));

 		if (map_start < map_end)
 			memmap_init_zone((unsigned long)(map_end - map_start),
 					 nid, zone, page_to_pfn(map_start),
 					 MEMMAP_EARLY);
 	}
 }

 static void __init_refok *vmem_alloc_pages(unsigned int order)
 {
 	if (slab_is_available())
 		return (void *)__get_free_pages(GFP_KERNEL, order);
 	return alloc_bootmem_pages((1 << order) * PAGE_SIZE);
 }

 static inline pmd_t *vmem_pmd_alloc(void)
 {
 	pmd_t *pmd;
 	int i;

 	pmd = vmem_alloc_pages(PMD_ALLOC_ORDER);
 	if (!pmd)
 		return NULL;
 	for (i = 0; i < PTRS_PER_PMD; i++)
 		pmd_clear_kernel(pmd + i);
 	return pmd;
 }

 static inline pte_t *vmem_pte_alloc(void)
 {
 	pte_t *pte;
 	pte_t empty_pte;
 	int i;

 	pte = vmem_alloc_pages(PTE_ALLOC_ORDER);
 	if (!pte)
 		return NULL;
 	pte_val(empty_pte) = _PAGE_TYPE_EMPTY;
 	for (i = 0; i < PTRS_PER_PTE; i++)
 		pte[i] = empty_pte;
 	return pte;
 }

 /*
  * Add a physical memory range to the 1:1 mapping.
  */
 static int vmem_add_range(unsigned long start, unsigned long size)
 {
 	unsigned long address;
 	pgd_t *pg_dir;
 	pmd_t *pm_dir;
 	pte_t *pt_dir;
 	pte_t  pte;
 	int ret = -ENOMEM;

 	for (address = start; address < start + size; address += PAGE_SIZE) {
 		pg_dir = pgd_offset_k(address);
 		if (pgd_none(*pg_dir)) {
 			pm_dir = vmem_pmd_alloc();
 			if (!pm_dir)
 				goto out;
 			pgd_populate_kernel(&init_mm, pg_dir, pm_dir);
 		}

 		pm_dir = pmd_offset(pg_dir, address);
 		if (pmd_none(*pm_dir)) {
 			pt_dir = vmem_pte_alloc();
 			if (!pt_dir)
 				goto out;
 			pmd_populate_kernel(&init_mm, pm_dir, pt_dir);
 		}

 		pt_dir = pte_offset_kernel(pm_dir, address);
 		pte = pfn_pte(address >> PAGE_SHIFT, PAGE_KERNEL);
 		*pt_dir = pte;
 	}
 	ret = 0;
 out:
 	flush_tlb_kernel_range(start, start + size);
 	return ret;
 }

 /*
  * Remove a physical memory range from the 1:1 mapping.
  * Currently only invalidates page table entries.
  */
 static void vmem_remove_range(unsigned long start, unsigned long size)
 {
 	unsigned long address;
 	pgd_t *pg_dir;
 	pmd_t *pm_dir;
 	pte_t *pt_dir;
 	pte_t  pte;

 	pte_val(pte) = _PAGE_TYPE_EMPTY;
 	for (address = start; address < start + size; address += PAGE_SIZE) {
 		pg_dir = pgd_offset_k(address);
 		if (pgd_none(*pg_dir))
 			continue;
 		pm_dir = pmd_offset(pg_dir, address);
 		if (pmd_none(*pm_dir))
 			continue;
 		pt_dir = pte_offset_kernel(pm_dir, address);
 		*pt_dir = pte;
 	}
 	flush_tlb_kernel_range(start, start + size);
 }

 /*
  * Add a backed mem_map array to the virtual mem_map array.
  */
 static int vmem_add_mem_map(unsigned long start, unsigned long size)
 {
 	unsigned long address, start_addr, end_addr;
 	struct page *map_start, *map_end;
 	pgd_t *pg_dir;
 	pmd_t *pm_dir;
 	pte_t *pt_dir;
 	pte_t  pte;
 	int ret = -ENOMEM;

 	map_start = vmem_map + PFN_DOWN(start);
 	map_end	= vmem_map + PFN_DOWN(start + size);

 	start_addr = (unsigned long) map_start & PAGE_MASK;
 	end_addr = PFN_ALIGN((unsigned long) map_end);

 	for (address = start_addr; address < end_addr; address += PAGE_SIZE) {
 		pg_dir = pgd_offset_k(address);
 		if (pgd_none(*pg_dir)) {
 			pm_dir = vmem_pmd_alloc();
 			if (!pm_dir)
 				goto out;
 			pgd_populate_kernel(&init_mm, pg_dir, pm_dir);
 		}

 		pm_dir = pmd_offset(pg_dir, address);
 		if (pmd_none(*pm_dir)) {
 			pt_dir = vmem_pte_alloc();
 			if (!pt_dir)
 				goto out;
 			pmd_populate_kernel(&init_mm, pm_dir, pt_dir);
 		}

 		pt_dir = pte_offset_kernel(pm_dir, address);
 		if (pte_none(*pt_dir)) {
 			unsigned long new_page;

 			new_page =__pa(vmem_alloc_pages(0));
 			if (!new_page)
 				goto out;
 			pte = pfn_pte(new_page >> PAGE_SHIFT, PAGE_KERNEL);
 			*pt_dir = pte;
 		}
 	}
 	ret = 0;
 out:
 	flush_tlb_kernel_range(start_addr, end_addr);
 	return ret;
 }

 static int vmem_add_mem(unsigned long start, unsigned long size)
 {
 	int ret;

 	ret = vmem_add_range(start, size);
 	if (ret)
 		return ret;
 	return vmem_add_mem_map(start, size);
 }

 /*
  * Add memory segment to the segment list if it doesn't overlap with
  * an already present segment.
  */
 static int insert_memory_segment(struct memory_segment *seg)
 {
 	struct memory_segment *tmp;

 	if (PFN_DOWN(seg->start + seg->size) > max_pfn ||
 	    seg->start + seg->size < seg->start)
 		return -ERANGE;

 	list_for_each_entry(tmp, &mem_segs, list) {
 		if (seg->start >= tmp->start + tmp->size)
 			continue;
 		if (seg->start + seg->size <= tmp->start)
 			continue;
 		return -ENOSPC;
 	}
 	list_add(&seg->list, &mem_segs);
 	return 0;
 }

 /*
  * Remove memory segment from the segment list.
  */
 static void remove_memory_segment(struct memory_segment *seg)
 {
 	list_del(&seg->list);
 }

 static void __remove_shared_memory(struct memory_segment *seg)
 {
 	remove_memory_segment(seg);
 	vmem_remove_range(seg->start, seg->size);
 }

 int remove_shared_memory(unsigned long start, unsigned long size)
 {
 	struct memory_segment *seg;
 	int ret;

 	mutex_lock(&vmem_mutex);

 	ret = -ENOENT;
 	list_for_each_entry(seg, &mem_segs, list) {
 		if (seg->start == start && seg->size == size)
 			break;
 	}

 	if (seg->start != start || seg->size != size)
 		goto out;

 	ret = 0;
 	__remove_shared_memory(seg);
 	kfree(seg);
 out:
 	mutex_unlock(&vmem_mutex);
 	return ret;
 }

 int add_shared_memory(unsigned long start, unsigned long size)
 {
 	struct memory_segment *seg;
 	struct page *page;
 	unsigned long pfn, num_pfn, end_pfn;
 	int ret;

 	mutex_lock(&vmem_mutex);
 	ret = -ENOMEM;
 	seg = kzalloc(sizeof(*seg), GFP_KERNEL);
 	if (!seg)
 		goto out;
 	seg->start = start;
 	seg->size = size;

 	ret = insert_memory_segment(seg);
 	if (ret)
 		goto out_free;

 	ret = vmem_add_mem(start, size);
 	if (ret)
 		goto out_remove;

 	pfn = PFN_DOWN(start);
 	num_pfn = PFN_DOWN(size);
 	end_pfn = pfn + num_pfn;

 	page = pfn_to_page(pfn);
 	memset(page, 0, num_pfn * sizeof(struct page));

 	for (; pfn < end_pfn; pfn++) {
 		page = pfn_to_page(pfn);
 		init_page_count(page);
 		reset_page_mapcount(page);
 		SetPageReserved(page);
 		INIT_LIST_HEAD(&page->lru);
 	}
 	goto out;

 out_remove:
 	__remove_shared_memory(seg);
 out_free:
 	kfree(seg);
 out:
 	mutex_unlock(&vmem_mutex);
 	return ret;
 }

 /*
  * map whole physical memory to virtual memory (identity mapping)
  */
 void __init vmem_map_init(void)
 {
 	unsigned long map_size;
 	int i;

 	map_size = ALIGN(max_low_pfn, MAX_ORDER_NR_PAGES) * sizeof(struct page);
 	vmalloc_end = PFN_ALIGN(VMALLOC_END_INIT) - PFN_ALIGN(map_size);
 	vmem_map = (struct page *) vmalloc_end;
 	NODE_DATA(0)->node_mem_map = vmem_map;

 	for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++)
 		vmem_add_mem(memory_chunk[i].addr, memory_chunk[i].size);
 }

 /*
  * Convert memory chunk array to a memory segment list so there is a single
  * list that contains both r/w memory and shared memory segments.
  */
 static int __init vmem_convert_memory_chunk(void)
 {
 	struct memory_segment *seg;
 	int i;

 	mutex_lock(&vmem_mutex);
 	for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++) {
 		if (!memory_chunk[i].size)
 			continue;
 		seg = kzalloc(sizeof(*seg), GFP_KERNEL);
 		if (!seg)
 			panic("Out of memory...\n");
 		seg->start = memory_chunk[i].addr;
 		seg->size = memory_chunk[i].size;
 		insert_memory_segment(seg);
 	}
 	mutex_unlock(&vmem_mutex);
 	return 0;
 }

 core_initcall(vmem_convert_memory_chunk);
	/*
	* arch/s390/mm/vmem.c
	*
	* Copyright IBM Corp. 2006
	* Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
	*/

	#include <linux/bootmem.h>
	#include <linux/pfn.h>
	#include <linux/mm.h>
	#include <linux/module.h>
	#include <linux/list.h>
	#include <asm/pgalloc.h>
	#include <asm/pgtable.h>
	#include <asm/setup.h>
	#include <asm/tlbflush.h>

	unsigned long vmalloc_end;
	EXPORT_SYMBOL(vmalloc_end);

	static struct page *vmem_map;
	static DEFINE_MUTEX(vmem_mutex);

	struct memory_segment {
	struct list_head list;
	unsigned long start;
	unsigned long size;
	};

	static LIST_HEAD(mem_segs);

	void __meminit memmap_init(unsigned long size, int nid, unsigned long zone,
	unsigned long start_pfn)
	{
	struct page start, end;
	struct page map_start, map_end;
	int i;

	start = pfn_to_page(start_pfn);
	end = start + size;

	for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++) {
	unsigned long cstart, cend;

	cstart = PFN_DOWN(memory_chunk[i].addr);
	cend = cstart + PFN_DOWN(memory_chunk[i].size);

	map_start = mem_map + cstart;
	map_end = mem_map + cend;

	if (map_start < start)
	map_start = start;
	if (map_end > end)
	map_end = end;

	map_start -= ((unsigned long) map_start & (PAGE_SIZE - 1))
	/ sizeof(struct page);
	map_end += ((PFN_ALIGN((unsigned long) map_end)
	- (unsigned long) map_end)
	/ sizeof(struct page));

	if (map_start < map_end)
	memmap_init_zone((unsigned long)(map_end - map_start),
	nid, zone, page_to_pfn(map_start),
	MEMMAP_EARLY);
	}
	}

	static void __init_refok *vmem_alloc_pages(unsigned int order)
	{
	if (slab_is_available())
	return (void *)__get_free_pages(GFP_KERNEL, order);
	return alloc_bootmem_pages((1 << order) * PAGE_SIZE);
	}

	static inline pmd_t *vmem_pmd_alloc(void)
	{
	pmd_t *pmd;
	int i;

	pmd = vmem_alloc_pages(PMD_ALLOC_ORDER);
	if (!pmd)
	return NULL;
	for (i = 0; i < PTRS_PER_PMD; i++)
	pmd_clear_kernel(pmd + i);
	return pmd;
	}

	static inline pte_t *vmem_pte_alloc(void)
	{
	pte_t *pte;
	pte_t empty_pte;
	int i;

	pte = vmem_alloc_pages(PTE_ALLOC_ORDER);
	if (!pte)
	return NULL;
	pte_val(empty_pte) = _PAGE_TYPE_EMPTY;
	for (i = 0; i < PTRS_PER_PTE; i++)
	pte[i] = empty_pte;
	return pte;
	}

	/*
	* Add a physical memory range to the 1:1 mapping.
	*/
	static int vmem_add_range(unsigned long start, unsigned long size)
	{
	unsigned long address;
	pgd_t *pg_dir;
	pmd_t *pm_dir;
	pte_t *pt_dir;
	pte_t pte;
	int ret = -ENOMEM;

	for (address = start; address < start + size; address += PAGE_SIZE) {
	pg_dir = pgd_offset_k(address);
	if (pgd_none(*pg_dir)) {
	pm_dir = vmem_pmd_alloc();
	if (!pm_dir)
	goto out;
	pgd_populate_kernel(&init_mm, pg_dir, pm_dir);
	}

	pm_dir = pmd_offset(pg_dir, address);
	if (pmd_none(*pm_dir)) {
	pt_dir = vmem_pte_alloc();
	if (!pt_dir)
	goto out;
	pmd_populate_kernel(&init_mm, pm_dir, pt_dir);
	}

	pt_dir = pte_offset_kernel(pm_dir, address);
	pte = pfn_pte(address >> PAGE_SHIFT, PAGE_KERNEL);
	*pt_dir = pte;
	}
	ret = 0;
	out:
	flush_tlb_kernel_range(start, start + size);
	return ret;
	}

	/*
	* Remove a physical memory range from the 1:1 mapping.
	* Currently only invalidates page table entries.
	*/
	static void vmem_remove_range(unsigned long start, unsigned long size)
	{
	unsigned long address;
	pgd_t *pg_dir;
	pmd_t *pm_dir;
	pte_t *pt_dir;
	pte_t pte;

	pte_val(pte) = _PAGE_TYPE_EMPTY;
	for (address = start; address < start + size; address += PAGE_SIZE) {
	pg_dir = pgd_offset_k(address);
	if (pgd_none(*pg_dir))
	continue;
	pm_dir = pmd_offset(pg_dir, address);
	if (pmd_none(*pm_dir))
	continue;
	pt_dir = pte_offset_kernel(pm_dir, address);
	*pt_dir = pte;
	}
	flush_tlb_kernel_range(start, start + size);
	}

	/*
	* Add a backed mem_map array to the virtual mem_map array.
	*/
	static int vmem_add_mem_map(unsigned long start, unsigned long size)
	{
	unsigned long address, start_addr, end_addr;
	struct page map_start, map_end;
	pgd_t *pg_dir;
	pmd_t *pm_dir;
	pte_t *pt_dir;
	pte_t pte;
	int ret = -ENOMEM;

	map_start = vmem_map + PFN_DOWN(start);
	map_end = vmem_map + PFN_DOWN(start + size);

	start_addr = (unsigned long) map_start & PAGE_MASK;
	end_addr = PFN_ALIGN((unsigned long) map_end);

	for (address = start_addr; address < end_addr; address += PAGE_SIZE) {
	pg_dir = pgd_offset_k(address);
	if (pgd_none(*pg_dir)) {
	pm_dir = vmem_pmd_alloc();
	if (!pm_dir)
	goto out;
	pgd_populate_kernel(&init_mm, pg_dir, pm_dir);
	}

	pm_dir = pmd_offset(pg_dir, address);
	if (pmd_none(*pm_dir)) {
	pt_dir = vmem_pte_alloc();
	if (!pt_dir)
	goto out;
	pmd_populate_kernel(&init_mm, pm_dir, pt_dir);
	}

	pt_dir = pte_offset_kernel(pm_dir, address);
	if (pte_none(*pt_dir)) {
	unsigned long new_page;

	new_page =__pa(vmem_alloc_pages(0));
	if (!new_page)
	goto out;
	pte = pfn_pte(new_page >> PAGE_SHIFT, PAGE_KERNEL);
	*pt_dir = pte;
	}
	}
	ret = 0;
	out:
	flush_tlb_kernel_range(start_addr, end_addr);
	return ret;
	}

	static int vmem_add_mem(unsigned long start, unsigned long size)
	{
	int ret;

	ret = vmem_add_range(start, size);
	if (ret)
	return ret;
	return vmem_add_mem_map(start, size);
	}

	/*
	* Add memory segment to the segment list if it doesn't overlap with
	* an already present segment.
	*/
	static int insert_memory_segment(struct memory_segment *seg)
	{
	struct memory_segment *tmp;

	if (PFN_DOWN(seg->start + seg->size) > max_pfn \|\|
	seg->start + seg->size < seg->start)
	return -ERANGE;

	list_for_each_entry(tmp, &mem_segs, list) {
	if (seg->start >= tmp->start + tmp->size)
	continue;
	if (seg->start + seg->size <= tmp->start)
	continue;
	return -ENOSPC;
	}
	list_add(&seg->list, &mem_segs);
	return 0;
	}

	/*
	* Remove memory segment from the segment list.
	*/
	static void remove_memory_segment(struct memory_segment *seg)
	{
	list_del(&seg->list);
	}

	static void __remove_shared_memory(struct memory_segment *seg)
	{
	remove_memory_segment(seg);
	vmem_remove_range(seg->start, seg->size);
	}

	int remove_shared_memory(unsigned long start, unsigned long size)
	{
	struct memory_segment *seg;
	int ret;

	mutex_lock(&vmem_mutex);

	ret = -ENOENT;
	list_for_each_entry(seg, &mem_segs, list) {
	if (seg->start == start && seg->size == size)
	break;
	}

	if (seg->start != start \|\| seg->size != size)
	goto out;

	ret = 0;
	__remove_shared_memory(seg);
	kfree(seg);
	out:
	mutex_unlock(&vmem_mutex);
	return ret;
	}

	int add_shared_memory(unsigned long start, unsigned long size)
	{
	struct memory_segment *seg;
	struct page *page;
	unsigned long pfn, num_pfn, end_pfn;
	int ret;

	mutex_lock(&vmem_mutex);
	ret = -ENOMEM;
	seg = kzalloc(sizeof(*seg), GFP_KERNEL);
	if (!seg)
	goto out;
	seg->start = start;
	seg->size = size;

	ret = insert_memory_segment(seg);
	if (ret)
	goto out_free;

	ret = vmem_add_mem(start, size);
	if (ret)
	goto out_remove;

	pfn = PFN_DOWN(start);
	num_pfn = PFN_DOWN(size);
	end_pfn = pfn + num_pfn;

	page = pfn_to_page(pfn);
	memset(page, 0, num_pfn * sizeof(struct page));

	for (; pfn < end_pfn; pfn++) {
	page = pfn_to_page(pfn);
	init_page_count(page);
	reset_page_mapcount(page);
	SetPageReserved(page);
	INIT_LIST_HEAD(&page->lru);
	}
	goto out;

	out_remove:
	__remove_shared_memory(seg);
	out_free:
	kfree(seg);
	out:
	mutex_unlock(&vmem_mutex);
	return ret;
	}

	/*
	* map whole physical memory to virtual memory (identity mapping)
	*/
	void __init vmem_map_init(void)
	{
	unsigned long map_size;
	int i;

	map_size = ALIGN(max_low_pfn, MAX_ORDER_NR_PAGES) * sizeof(struct page);
	vmalloc_end = PFN_ALIGN(VMALLOC_END_INIT) - PFN_ALIGN(map_size);
	vmem_map = (struct page *) vmalloc_end;
	NODE_DATA(0)->node_mem_map = vmem_map;

	for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++)
	vmem_add_mem(memory_chunk[i].addr, memory_chunk[i].size);
	}

	/*
	* Convert memory chunk array to a memory segment list so there is a single
	* list that contains both r/w memory and shared memory segments.
	*/
	static int __init vmem_convert_memory_chunk(void)
	{
	struct memory_segment *seg;
	int i;

	mutex_lock(&vmem_mutex);
	for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++) {
	if (!memory_chunk[i].size)
	continue;
	seg = kzalloc(sizeof(*seg), GFP_KERNEL);
	if (!seg)
	panic("Out of memory...\n");
	seg->start = memory_chunk[i].addr;
	seg->size = memory_chunk[i].size;
	insert_memory_segment(seg);
	}
	mutex_unlock(&vmem_mutex);
	return 0;
	}

	core_initcall(vmem_convert_memory_chunk);