arch/s390/mm/vmem.c - kernel/windcharger - Git at Google

 /*
  *  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 <linux/hugetlb.h>
 #include <asm/pgalloc.h>
 #include <asm/pgtable.h>
 #include <asm/setup.h>
 #include <asm/tlbflush.h>
 #include <asm/sections.h>

 static DEFINE_MUTEX(vmem_mutex);

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

 static LIST_HEAD(mem_segs);

 static void __ref *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 pud_t *vmem_pud_alloc(void)
 {
 	pud_t *pud = NULL;

 #ifdef CONFIG_64BIT
 	pud = vmem_alloc_pages(2);
 	if (!pud)
 		return NULL;
 	clear_table((unsigned long *) pud, _REGION3_ENTRY_EMPTY, PAGE_SIZE * 4);
 #endif
 	return pud;
 }

 static inline pmd_t *vmem_pmd_alloc(void)
 {
 	pmd_t *pmd = NULL;

 #ifdef CONFIG_64BIT
 	pmd = vmem_alloc_pages(2);
 	if (!pmd)
 		return NULL;
 	clear_table((unsigned long *) pmd, _SEGMENT_ENTRY_EMPTY, PAGE_SIZE * 4);
 #endif
 	return pmd;
 }

 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;
 }

 /*
  * Add a physical memory range to the 1:1 mapping.
  */
 static int vmem_add_mem(unsigned long start, unsigned long size, int ro)
 {
 	unsigned long address;
 	pgd_t *pg_dir;
 	pud_t *pu_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)) {
 			pu_dir = vmem_pud_alloc();
 			if (!pu_dir)
 				goto out;
 			pgd_populate_kernel(&init_mm, pg_dir, pu_dir);
 		}

 		pu_dir = pud_offset(pg_dir, address);
 		if (pud_none(*pu_dir)) {
 			pm_dir = vmem_pmd_alloc();
 			if (!pm_dir)
 				goto out;
 			pud_populate_kernel(&init_mm, pu_dir, pm_dir);
 		}

 		pte = mk_pte_phys(address, __pgprot(ro ? _PAGE_RO : 0));
 		pm_dir = pmd_offset(pu_dir, address);

 #ifdef __s390x__
 		if (MACHINE_HAS_HPAGE && !(address & ~HPAGE_MASK) &&
 		    (address + HPAGE_SIZE <= start + size) &&
 		    (address >= HPAGE_SIZE)) {
 			pte_val(pte) |= _SEGMENT_ENTRY_LARGE;
 			pmd_val(*pm_dir) = pte_val(pte);
 			address += HPAGE_SIZE - PAGE_SIZE;
 			continue;
 		}
 #endif
 		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);
 		*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;
 	pud_t *pu_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);
 		pu_dir = pud_offset(pg_dir, address);
 		if (pud_none(*pu_dir))
 			continue;
 		pm_dir = pmd_offset(pu_dir, address);
 		if (pmd_none(*pm_dir))
 			continue;

 		if (pmd_huge(*pm_dir)) {
 			pmd_clear_kernel(pm_dir);
 			address += HPAGE_SIZE - PAGE_SIZE;
 			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.
  */
 int __meminit vmemmap_populate(struct page *start, unsigned long nr, int node)
 {
 	unsigned long address, start_addr, end_addr;
 	pgd_t *pg_dir;
 	pud_t *pu_dir;
 	pmd_t *pm_dir;
 	pte_t *pt_dir;
 	pte_t  pte;
 	int ret = -ENOMEM;

 	start_addr = (unsigned long) start;
 	end_addr = (unsigned long) (start + nr);

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

 		pu_dir = pud_offset(pg_dir, address);
 		if (pud_none(*pu_dir)) {
 			pm_dir = vmem_pmd_alloc();
 			if (!pm_dir)
 				goto out;
 			pud_populate_kernel(&init_mm, pu_dir, pm_dir);
 		}

 		pm_dir = pmd_offset(pu_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;
 		}
 	}
 	memset(start, 0, nr * sizeof(struct page));
 	ret = 0;
 out:
 	flush_tlb_kernel_range(start_addr, end_addr);
 	return ret;
 }

 /*
  * 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 (seg->start + seg->size > VMEM_MAX_PHYS ||
 	    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 vmem_remove_mapping(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 vmem_add_mapping(unsigned long start, unsigned long size)
 {
 	struct memory_segment *seg;
 	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, 0);
 	if (ret)
 		goto out_remove;
 	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)
  * we reserve enough space in the vmalloc area for vmemmap to hotplug
  * additional memory segments.
  */
 void __init vmem_map_init(void)
 {
 	unsigned long ro_start, ro_end;
 	unsigned long start, end;
 	int i;

 	INIT_LIST_HEAD(&init_mm.context.crst_list);
 	INIT_LIST_HEAD(&init_mm.context.pgtable_list);
 	init_mm.context.noexec = 0;
 	ro_start = ((unsigned long)&_stext) & PAGE_MASK;
 	ro_end = PFN_ALIGN((unsigned long)&_eshared);
 	for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++) {
 		start = memory_chunk[i].addr;
 		end = memory_chunk[i].addr + memory_chunk[i].size;
 		if (start >= ro_end || end <= ro_start)
 			vmem_add_mem(start, end - start, 0);
 		else if (start >= ro_start && end <= ro_end)
 			vmem_add_mem(start, end - start, 1);
 		else if (start >= ro_start) {
 			vmem_add_mem(start, ro_end - start, 1);
 			vmem_add_mem(ro_end, end - ro_end, 0);
 		} else if (end < ro_end) {
 			vmem_add_mem(start, ro_start - start, 0);
 			vmem_add_mem(ro_start, end - ro_start, 1);
 		} else {
 			vmem_add_mem(start, ro_start - start, 0);
 			vmem_add_mem(ro_start, ro_end - ro_start, 1);
 			vmem_add_mem(ro_end, end - ro_end, 0);
 		}
 	}
 }

 /*
  * 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; 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 <linux/hugetlb.h>
	#include <asm/pgalloc.h>
	#include <asm/pgtable.h>
	#include <asm/setup.h>
	#include <asm/tlbflush.h>
	#include <asm/sections.h>

	static DEFINE_MUTEX(vmem_mutex);

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

	static LIST_HEAD(mem_segs);

	static void __ref *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 pud_t *vmem_pud_alloc(void)
	{
	pud_t *pud = NULL;

	#ifdef CONFIG_64BIT
	pud = vmem_alloc_pages(2);
	if (!pud)
	return NULL;
	clear_table((unsigned long ) pud, _REGION3_ENTRY_EMPTY, PAGE_SIZE 4);
	#endif
	return pud;
	}

	static inline pmd_t *vmem_pmd_alloc(void)
	{
	pmd_t *pmd = NULL;

	#ifdef CONFIG_64BIT
	pmd = vmem_alloc_pages(2);
	if (!pmd)
	return NULL;
	clear_table((unsigned long ) pmd, _SEGMENT_ENTRY_EMPTY, PAGE_SIZE 4);
	#endif
	return pmd;
	}

	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;
	}

	/*
	* Add a physical memory range to the 1:1 mapping.
	*/
	static int vmem_add_mem(unsigned long start, unsigned long size, int ro)
	{
	unsigned long address;
	pgd_t *pg_dir;
	pud_t *pu_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)) {
	pu_dir = vmem_pud_alloc();
	if (!pu_dir)
	goto out;
	pgd_populate_kernel(&init_mm, pg_dir, pu_dir);
	}

	pu_dir = pud_offset(pg_dir, address);
	if (pud_none(*pu_dir)) {
	pm_dir = vmem_pmd_alloc();
	if (!pm_dir)
	goto out;
	pud_populate_kernel(&init_mm, pu_dir, pm_dir);
	}

	pte = mk_pte_phys(address, __pgprot(ro ? _PAGE_RO : 0));
	pm_dir = pmd_offset(pu_dir, address);

	#ifdef __s390x__
	if (MACHINE_HAS_HPAGE && !(address & ~HPAGE_MASK) &&
	(address + HPAGE_SIZE <= start + size) &&
	(address >= HPAGE_SIZE)) {
	pte_val(pte) \|= _SEGMENT_ENTRY_LARGE;
	pmd_val(*pm_dir) = pte_val(pte);
	address += HPAGE_SIZE - PAGE_SIZE;
	continue;
	}
	#endif
	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);
	*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;
	pud_t *pu_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);
	pu_dir = pud_offset(pg_dir, address);
	if (pud_none(*pu_dir))
	continue;
	pm_dir = pmd_offset(pu_dir, address);
	if (pmd_none(*pm_dir))
	continue;

	if (pmd_huge(*pm_dir)) {
	pmd_clear_kernel(pm_dir);
	address += HPAGE_SIZE - PAGE_SIZE;
	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.
	*/
	int __meminit vmemmap_populate(struct page *start, unsigned long nr, int node)
	{
	unsigned long address, start_addr, end_addr;
	pgd_t *pg_dir;
	pud_t *pu_dir;
	pmd_t *pm_dir;
	pte_t *pt_dir;
	pte_t pte;
	int ret = -ENOMEM;

	start_addr = (unsigned long) start;
	end_addr = (unsigned long) (start + nr);

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

	pu_dir = pud_offset(pg_dir, address);
	if (pud_none(*pu_dir)) {
	pm_dir = vmem_pmd_alloc();
	if (!pm_dir)
	goto out;
	pud_populate_kernel(&init_mm, pu_dir, pm_dir);
	}

	pm_dir = pmd_offset(pu_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;
	}
	}
	memset(start, 0, nr * sizeof(struct page));
	ret = 0;
	out:
	flush_tlb_kernel_range(start_addr, end_addr);
	return ret;
	}

	/*
	* 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 (seg->start + seg->size > VMEM_MAX_PHYS \|\|
	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 vmem_remove_mapping(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 vmem_add_mapping(unsigned long start, unsigned long size)
	{
	struct memory_segment *seg;
	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, 0);
	if (ret)
	goto out_remove;
	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)
	* we reserve enough space in the vmalloc area for vmemmap to hotplug
	* additional memory segments.
	*/
	void __init vmem_map_init(void)
	{
	unsigned long ro_start, ro_end;
	unsigned long start, end;
	int i;

	INIT_LIST_HEAD(&init_mm.context.crst_list);
	INIT_LIST_HEAD(&init_mm.context.pgtable_list);
	init_mm.context.noexec = 0;
	ro_start = ((unsigned long)&_stext) & PAGE_MASK;
	ro_end = PFN_ALIGN((unsigned long)&_eshared);
	for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++) {
	start = memory_chunk[i].addr;
	end = memory_chunk[i].addr + memory_chunk[i].size;
	if (start >= ro_end \|\| end <= ro_start)
	vmem_add_mem(start, end - start, 0);
	else if (start >= ro_start && end <= ro_end)
	vmem_add_mem(start, end - start, 1);
	else if (start >= ro_start) {
	vmem_add_mem(start, ro_end - start, 1);
	vmem_add_mem(ro_end, end - ro_end, 0);
	} else if (end < ro_end) {
	vmem_add_mem(start, ro_start - start, 0);
	vmem_add_mem(ro_start, end - ro_start, 1);
	} else {
	vmem_add_mem(start, ro_start - start, 0);
	vmem_add_mem(ro_start, ro_end - ro_start, 1);
	vmem_add_mem(ro_end, end - ro_end, 0);
	}
	}
	}

	/*
	* 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; 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);