[GitHub/mt8127/android_kernel_alcatel_ttab.git] / arch / x86 / mm / pgtable_32.c

/*
 *  linux/arch/i386/mm/pgtable.c
 */

#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/mm.h>
#include <linux/nmi.h>
#include <linux/swap.h>
#include <linux/smp.h>
#include <linux/highmem.h>
#include <linux/slab.h>
#include <linux/pagemap.h>
#include <linux/spinlock.h>
#include <linux/module.h>
#include <linux/quicklist.h>

#include <asm/system.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/fixmap.h>
#include <asm/e820.h>
#include <asm/tlb.h>
#include <asm/tlbflush.h>

void show_mem(void)
{
	int total = 0, reserved = 0;
	int shared = 0, cached = 0;
	int highmem = 0;
	struct page *page;
	pg_data_t *pgdat;
	unsigned long i;
	unsigned long flags;

	printk(KERN_INFO "Mem-info:\n");
	show_free_areas();
	printk(KERN_INFO "Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
	for_each_online_pgdat(pgdat) {
		pgdat_resize_lock(pgdat, &flags);
		for (i = 0; i < pgdat->node_spanned_pages; ++i) {
			if (unlikely(i % MAX_ORDER_NR_PAGES == 0))
				touch_nmi_watchdog();
			page = pgdat_page_nr(pgdat, i);
			total++;
			if (PageHighMem(page))
				highmem++;
			if (PageReserved(page))
				reserved++;
			else if (PageSwapCache(page))
				cached++;
			else if (page_count(page))
				shared += page_count(page) - 1;
		}
		pgdat_resize_unlock(pgdat, &flags);
	}
	printk(KERN_INFO "%d pages of RAM\n", total);
	printk(KERN_INFO "%d pages of HIGHMEM\n", highmem);
	printk(KERN_INFO "%d reserved pages\n", reserved);
	printk(KERN_INFO "%d pages shared\n", shared);
	printk(KERN_INFO "%d pages swap cached\n", cached);

	printk(KERN_INFO "%lu pages dirty\n", global_page_state(NR_FILE_DIRTY));
	printk(KERN_INFO "%lu pages writeback\n",
					global_page_state(NR_WRITEBACK));
	printk(KERN_INFO "%lu pages mapped\n", global_page_state(NR_FILE_MAPPED));
	printk(KERN_INFO "%lu pages slab\n",
		global_page_state(NR_SLAB_RECLAIMABLE) +
		global_page_state(NR_SLAB_UNRECLAIMABLE));
	printk(KERN_INFO "%lu pages pagetables\n",
					global_page_state(NR_PAGETABLE));
}

/*
 * Associate a virtual page frame with a given physical page frame 
 * and protection flags for that frame.
 */ 
static void set_pte_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags)
{
	pgd_t *pgd;
	pud_t *pud;
	pmd_t *pmd;
	pte_t *pte;

	pgd = swapper_pg_dir + pgd_index(vaddr);
	if (pgd_none(*pgd)) {
		BUG();
		return;
	}
	pud = pud_offset(pgd, vaddr);
	if (pud_none(*pud)) {
		BUG();
		return;
	}
	pmd = pmd_offset(pud, vaddr);
	if (pmd_none(*pmd)) {
		BUG();
		return;
	}
	pte = pte_offset_kernel(pmd, vaddr);
	if (pgprot_val(flags))
		set_pte_present(&init_mm, vaddr, pte, pfn_pte(pfn, flags));
	else
		pte_clear(&init_mm, vaddr, pte);

	/*
	 * It's enough to flush this one mapping.
	 * (PGE mappings get flushed as well)
	 */
	__flush_tlb_one(vaddr);
}

/*
 * Associate a large virtual page frame with a given physical page frame 
 * and protection flags for that frame. pfn is for the base of the page,
 * vaddr is what the page gets mapped to - both must be properly aligned. 
 * The pmd must already be instantiated. Assumes PAE mode.
 */ 
void set_pmd_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags)
{
	pgd_t *pgd;
	pud_t *pud;
	pmd_t *pmd;

	if (vaddr & (PMD_SIZE-1)) {		/* vaddr is misaligned */
		printk(KERN_WARNING "set_pmd_pfn: vaddr misaligned\n");
		return; /* BUG(); */
	}
	if (pfn & (PTRS_PER_PTE-1)) {		/* pfn is misaligned */
		printk(KERN_WARNING "set_pmd_pfn: pfn misaligned\n");
		return; /* BUG(); */
	}
	pgd = swapper_pg_dir + pgd_index(vaddr);
	if (pgd_none(*pgd)) {
		printk(KERN_WARNING "set_pmd_pfn: pgd_none\n");
		return; /* BUG(); */
	}
	pud = pud_offset(pgd, vaddr);
	pmd = pmd_offset(pud, vaddr);
	set_pmd(pmd, pfn_pmd(pfn, flags));
	/*
	 * It's enough to flush this one mapping.
	 * (PGE mappings get flushed as well)
	 */
	__flush_tlb_one(vaddr);
}

static int fixmaps;
unsigned long __FIXADDR_TOP = 0xfffff000;
EXPORT_SYMBOL(__FIXADDR_TOP);

void __set_fixmap (enum fixed_addresses idx, unsigned long phys, pgprot_t flags)
{
	unsigned long address = __fix_to_virt(idx);

	if (idx >= __end_of_fixed_addresses) {
		BUG();
		return;
	}
	set_pte_pfn(address, phys >> PAGE_SHIFT, flags);
	fixmaps++;
}

/**
 * reserve_top_address - reserves a hole in the top of kernel address space
 * @reserve - size of hole to reserve
 *
 * Can be used to relocate the fixmap area and poke a hole in the top
 * of kernel address space to make room for a hypervisor.
 */
void reserve_top_address(unsigned long reserve)
{
	BUG_ON(fixmaps > 0);
	printk(KERN_INFO "Reserving virtual address space above 0x%08x\n",
	       (int)-reserve);
	__FIXADDR_TOP = -reserve - PAGE_SIZE;
	__VMALLOC_RESERVE += reserve;
}

pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
{
	return (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
}

pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long address)
{
	struct page *pte;

#ifdef CONFIG_HIGHPTE
	pte = alloc_pages(GFP_KERNEL|__GFP_HIGHMEM|__GFP_REPEAT|__GFP_ZERO, 0);
#else
	pte = alloc_pages(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO, 0);
#endif
	if (pte)
		pgtable_page_ctor(pte);
	return pte;
}

/*
 * List of all pgd's needed for non-PAE so it can invalidate entries
 * in both cached and uncached pgd's; not needed for PAE since the
 * kernel pmd is shared. If PAE were not to share the pmd a similar
 * tactic would be needed. This is essentially codepath-based locking
 * against pageattr.c; it is the unique case in which a valid change
 * of kernel pagetables can't be lazily synchronized by vmalloc faults.
 * vmalloc faults work because attached pagetables are never freed.
 * -- wli
 */
static inline void pgd_list_add(pgd_t *pgd)
{
	struct page *page = virt_to_page(pgd);

	list_add(&page->lru, &pgd_list);
}

static inline void pgd_list_del(pgd_t *pgd)
{
	struct page *page = virt_to_page(pgd);

	list_del(&page->lru);
}

#define UNSHARED_PTRS_PER_PGD				\
	(SHARED_KERNEL_PMD ? USER_PTRS_PER_PGD : PTRS_PER_PGD)

static void pgd_ctor(void *p)
{
	pgd_t *pgd = p;
	unsigned long flags;

	/* Clear usermode parts of PGD */
	memset(pgd, 0, USER_PTRS_PER_PGD*sizeof(pgd_t));

	spin_lock_irqsave(&pgd_lock, flags);

	/* If the pgd points to a shared pagetable level (either the
	   ptes in non-PAE, or shared PMD in PAE), then just copy the
	   references from swapper_pg_dir. */
	if (PAGETABLE_LEVELS == 2 ||
	    (PAGETABLE_LEVELS == 3 && SHARED_KERNEL_PMD)) {
		clone_pgd_range(pgd + USER_PTRS_PER_PGD,
				swapper_pg_dir + USER_PTRS_PER_PGD,
				KERNEL_PGD_PTRS);
		paravirt_alloc_pd_clone(__pa(pgd) >> PAGE_SHIFT,
					__pa(swapper_pg_dir) >> PAGE_SHIFT,
					USER_PTRS_PER_PGD,
					KERNEL_PGD_PTRS);
	}

	/* list required to sync kernel mapping updates */
	if (!SHARED_KERNEL_PMD)
		pgd_list_add(pgd);

	spin_unlock_irqrestore(&pgd_lock, flags);
}

static void pgd_dtor(void *pgd)
{
	unsigned long flags; /* can be called from interrupt context */

	if (SHARED_KERNEL_PMD)
		return;

	spin_lock_irqsave(&pgd_lock, flags);
	pgd_list_del(pgd);
	spin_unlock_irqrestore(&pgd_lock, flags);
}

#ifdef CONFIG_X86_PAE
/*
 * Mop up any pmd pages which may still be attached to the pgd.
 * Normally they will be freed by munmap/exit_mmap, but any pmd we
 * preallocate which never got a corresponding vma will need to be
 * freed manually.
 */
static void pgd_mop_up_pmds(struct mm_struct *mm, pgd_t *pgdp)
{
	int i;

	for(i = 0; i < UNSHARED_PTRS_PER_PGD; i++) {
		pgd_t pgd = pgdp[i];

		if (pgd_val(pgd) != 0) {
			pmd_t *pmd = (pmd_t *)pgd_page_vaddr(pgd);

			pgdp[i] = native_make_pgd(0);

			paravirt_release_pd(pgd_val(pgd) >> PAGE_SHIFT);
			pmd_free(mm, pmd);
		}
	}
}

/*
 * In PAE mode, we need to do a cr3 reload (=tlb flush) when
 * updating the top-level pagetable entries to guarantee the
 * processor notices the update.  Since this is expensive, and
 * all 4 top-level entries are used almost immediately in a
 * new process's life, we just pre-populate them here.
 *
 * Also, if we're in a paravirt environment where the kernel pmd is
 * not shared between pagetables (!SHARED_KERNEL_PMDS), we allocate
 * and initialize the kernel pmds here.
 */
static int pgd_prepopulate_pmd(struct mm_struct *mm, pgd_t *pgd)
{
	pud_t *pud;
	unsigned long addr;
	int i;

	pud = pud_offset(pgd, 0);
 	for (addr = i = 0; i < UNSHARED_PTRS_PER_PGD;
	     i++, pud++, addr += PUD_SIZE) {
		pmd_t *pmd = pmd_alloc_one(mm, addr);

		if (!pmd) {
			pgd_mop_up_pmds(mm, pgd);
			return 0;
		}

		if (i >= USER_PTRS_PER_PGD)
			memcpy(pmd, (pmd_t *)pgd_page_vaddr(swapper_pg_dir[i]),
			       sizeof(pmd_t) * PTRS_PER_PMD);

		pud_populate(mm, pud, pmd);
	}

	return 1;
}
#else  /* !CONFIG_X86_PAE */
/* No need to prepopulate any pagetable entries in non-PAE modes. */
static int pgd_prepopulate_pmd(struct mm_struct *mm, pgd_t *pgd)
{
	return 1;
}

static void pgd_mop_up_pmds(struct mm_struct *mm, pgd_t *pgdp)
{
}
#endif	/* CONFIG_X86_PAE */

pgd_t *pgd_alloc(struct mm_struct *mm)
{
	pgd_t *pgd = quicklist_alloc(0, GFP_KERNEL, pgd_ctor);

	mm->pgd = pgd;		/* so that alloc_pd can use it */

	if (pgd && !pgd_prepopulate_pmd(mm, pgd)) {
		quicklist_free(0, pgd_dtor, pgd);
		pgd = NULL;
	}

	return pgd;
}

void pgd_free(struct mm_struct *mm, pgd_t *pgd)
{
	pgd_mop_up_pmds(mm, pgd);
	quicklist_free(0, pgd_dtor, pgd);
}

void check_pgt_cache(void)
{
	quicklist_trim(0, pgd_dtor, 25, 16);
}

void __pte_free_tlb(struct mmu_gather *tlb, struct page *pte)
{
	pgtable_page_dtor(pte);
	paravirt_release_pt(page_to_pfn(pte));
	tlb_remove_page(tlb, pte);
}

#ifdef CONFIG_X86_PAE

void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd)
{
	paravirt_release_pd(__pa(pmd) >> PAGE_SHIFT);
	tlb_remove_page(tlb, virt_to_page(pmd));
}

#endif
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/arch/i386/mm/pgtable.c
	3	*/
	4
1da177e4 LT	5	#include <linux/sched.h>
	6	#include <linux/kernel.h>
	7	#include <linux/errno.h>
	8	#include <linux/mm.h>
27eb0b28	9	#include <linux/nmi.h>
1da177e4 LT	10	#include <linux/swap.h>
	11	#include <linux/smp.h>
	12	#include <linux/highmem.h>
	13	#include <linux/slab.h>
	14	#include <linux/pagemap.h>
	15	#include <linux/spinlock.h>
052e7994	16	#include <linux/module.h>
f1d1a842	17	#include <linux/quicklist.h>
1da177e4 LT	18
	19	#include <asm/system.h>
	20	#include <asm/pgtable.h>
	21	#include <asm/pgalloc.h>
	22	#include <asm/fixmap.h>
	23	#include <asm/e820.h>
	24	#include <asm/tlb.h>
	25	#include <asm/tlbflush.h>
	26
	27	void show_mem(void)
	28	{
	29	int total = 0, reserved = 0;
	30	int shared = 0, cached = 0;
	31	int highmem = 0;
	32	struct page *page;
	33	pg_data_t *pgdat;
	34	unsigned long i;
208d54e5	35	unsigned long flags;
1da177e4	36
f90e7185	37	printk(KERN_INFO "Mem-info:\n");
1da177e4	38	show_free_areas();
f90e7185	39	printk(KERN_INFO "Free swap: %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
ec936fc5	40	for_each_online_pgdat(pgdat) {
208d54e5	41	pgdat_resize_lock(pgdat, &flags);
1da177e4	42	for (i = 0; i < pgdat->node_spanned_pages; ++i) {
27eb0b28 PB	43	if (unlikely(i % MAX_ORDER_NR_PAGES == 0))
27eb0b28 PB	44	touch_nmi_watchdog();
408fde81	45	page = pgdat_page_nr(pgdat, i);
1da177e4 LT	46	total++;
	47	if (PageHighMem(page))
	48	highmem++;
	49	if (PageReserved(page))
	50	reserved++;
	51	else if (PageSwapCache(page))
	52	cached++;
	53	else if (page_count(page))
	54	shared += page_count(page) - 1;
	55	}
208d54e5	56	pgdat_resize_unlock(pgdat, &flags);
1da177e4	57	}
f90e7185 CL	58	printk(KERN_INFO "%d pages of RAM\n", total);
	59	printk(KERN_INFO "%d pages of HIGHMEM\n", highmem);
	60	printk(KERN_INFO "%d reserved pages\n", reserved);
	61	printk(KERN_INFO "%d pages shared\n", shared);
	62	printk(KERN_INFO "%d pages swap cached\n", cached);
6f4e1e50	63
b1e7a8fd	64	printk(KERN_INFO "%lu pages dirty\n", global_page_state(NR_FILE_DIRTY));
ce866b34 CL	65	printk(KERN_INFO "%lu pages writeback\n",
ce866b34 CL	66	global_page_state(NR_WRITEBACK));
65ba55f5	67	printk(KERN_INFO "%lu pages mapped\n", global_page_state(NR_FILE_MAPPED));
972d1a7b CL	68	printk(KERN_INFO "%lu pages slab\n",
	69	global_page_state(NR_SLAB_RECLAIMABLE) +
	70	global_page_state(NR_SLAB_UNRECLAIMABLE));
df849a15 CL	71	printk(KERN_INFO "%lu pages pagetables\n",
df849a15 CL	72	global_page_state(NR_PAGETABLE));
1da177e4 LT	73	}
	74
	75	/*
	76	* Associate a virtual page frame with a given physical page frame
	77	* and protection flags for that frame.
	78	*/
	79	static void set_pte_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags)
	80	{
	81	pgd_t *pgd;
	82	pud_t *pud;
	83	pmd_t *pmd;
	84	pte_t *pte;
	85
	86	pgd = swapper_pg_dir + pgd_index(vaddr);
	87	if (pgd_none(*pgd)) {
	88	BUG();
	89	return;
	90	}
	91	pud = pud_offset(pgd, vaddr);
	92	if (pud_none(*pud)) {
	93	BUG();
	94	return;
	95	}
	96	pmd = pmd_offset(pud, vaddr);
	97	if (pmd_none(*pmd)) {
	98	BUG();
	99	return;
	100	}
	101	pte = pte_offset_kernel(pmd, vaddr);
b0bfece4	102	if (pgprot_val(flags))
aa506dc7	103	set_pte_present(&init_mm, vaddr, pte, pfn_pte(pfn, flags));
b0bfece4 JB	104	else
b0bfece4 JB	105	pte_clear(&init_mm, vaddr, pte);
1da177e4 LT	106
	107	/*
	108	* It's enough to flush this one mapping.
	109	* (PGE mappings get flushed as well)
	110	*/
	111	__flush_tlb_one(vaddr);
	112	}
	113
	114	/*
	115	* Associate a large virtual page frame with a given physical page frame
	116	* and protection flags for that frame. pfn is for the base of the page,
	117	* vaddr is what the page gets mapped to - both must be properly aligned.
	118	* The pmd must already be instantiated. Assumes PAE mode.
	119	*/
	120	void set_pmd_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags)
	121	{
	122	pgd_t *pgd;
	123	pud_t *pud;
	124	pmd_t *pmd;
	125
	126	if (vaddr & (PMD_SIZE-1)) { /* vaddr is misaligned */
f90e7185	127	printk(KERN_WARNING "set_pmd_pfn: vaddr misaligned\n");
1da177e4 LT	128	return; /* BUG(); */
	129	}
	130	if (pfn & (PTRS_PER_PTE-1)) { /* pfn is misaligned */
f90e7185	131	printk(KERN_WARNING "set_pmd_pfn: pfn misaligned\n");
1da177e4 LT	132	return; /* BUG(); */
	133	}
	134	pgd = swapper_pg_dir + pgd_index(vaddr);
	135	if (pgd_none(*pgd)) {
f90e7185	136	printk(KERN_WARNING "set_pmd_pfn: pgd_none\n");
1da177e4 LT	137	return; /* BUG(); */
	138	}
	139	pud = pud_offset(pgd, vaddr);
	140	pmd = pmd_offset(pud, vaddr);
	141	set_pmd(pmd, pfn_pmd(pfn, flags));
	142	/*
	143	* It's enough to flush this one mapping.
	144	* (PGE mappings get flushed as well)
	145	*/
	146	__flush_tlb_one(vaddr);
	147	}
	148
052e7994	149	static int fixmaps;
052e7994 JF	150	unsigned long __FIXADDR_TOP = 0xfffff000;
052e7994 JF	151	EXPORT_SYMBOL(__FIXADDR_TOP);
052e7994	152
1da177e4 LT	153	void __set_fixmap (enum fixed_addresses idx, unsigned long phys, pgprot_t flags)
	154	{
	155	unsigned long address = __fix_to_virt(idx);
	156
	157	if (idx >= __end_of_fixed_addresses) {
	158	BUG();
	159	return;
	160	}
	161	set_pte_pfn(address, phys >> PAGE_SHIFT, flags);
052e7994 JF	162	fixmaps++;
	163	}
	164
	165	/**
	166	* reserve_top_address - reserves a hole in the top of kernel address space
	167	* @reserve - size of hole to reserve
	168	*
	169	* Can be used to relocate the fixmap area and poke a hole in the top
	170	* of kernel address space to make room for a hypervisor.
	171	*/
	172	void reserve_top_address(unsigned long reserve)
	173	{
	174	BUG_ON(fixmaps > 0);
7ce0bcfd ZA	175	printk(KERN_INFO "Reserving virtual address space above 0x%08x\n",
7ce0bcfd ZA	176	(int)-reserve);
052e7994 JF	177	__FIXADDR_TOP = -reserve - PAGE_SIZE;
052e7994 JF	178	__VMALLOC_RESERVE += reserve;
1da177e4 LT	179	}
	180
	181	pte_t pte_alloc_one_kernel(struct mm_struct mm, unsigned long address)
	182	{
	183	return (pte_t *)__get_free_page(GFP_KERNEL\|__GFP_REPEAT\|__GFP_ZERO);
	184	}
	185
2f569afd	186	pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long address)
1da177e4 LT	187	{
	188	struct page *pte;
	189
	190	#ifdef CONFIG_HIGHPTE
	191	pte = alloc_pages(GFP_KERNEL\|__GFP_HIGHMEM\|__GFP_REPEAT\|__GFP_ZERO, 0);
	192	#else
	193	pte = alloc_pages(GFP_KERNEL\|__GFP_REPEAT\|__GFP_ZERO, 0);
	194	#endif
2f569afd MS	195	if (pte)
2f569afd MS	196	pgtable_page_ctor(pte);
1da177e4 LT	197	return pte;
	198	}
	199
1da177e4 LT	200	/*
	201	* List of all pgd's needed for non-PAE so it can invalidate entries
	202	* in both cached and uncached pgd's; not needed for PAE since the
	203	* kernel pmd is shared. If PAE were not to share the pmd a similar
	204	* tactic would be needed. This is essentially codepath-based locking
	205	* against pageattr.c; it is the unique case in which a valid change
	206	* of kernel pagetables can't be lazily synchronized by vmalloc faults.
	207	* vmalloc faults work because attached pagetables are never freed.
1da177e4 LT	208	* -- wli
1da177e4 LT	209	*/
1da177e4 LT	210	static inline void pgd_list_add(pgd_t *pgd)
	211	{
	212	struct page *page = virt_to_page(pgd);
e3ed910d JF	213
e3ed910d JF	214	list_add(&page->lru, &pgd_list);
1da177e4 LT	215	}
	216
	217	static inline void pgd_list_del(pgd_t *pgd)
	218	{
e3ed910d JF	219	struct page *page = virt_to_page(pgd);
	220
	221	list_del(&page->lru);
1da177e4 LT	222	}
1da177e4 LT	223
e618c957 JF	224	#define UNSHARED_PTRS_PER_PGD \
e618c957 JF	225	(SHARED_KERNEL_PMD ? USER_PTRS_PER_PGD : PTRS_PER_PGD)
f1d1a842	226
e618c957	227	static void pgd_ctor(void *p)
1da177e4	228	{
e618c957	229	pgd_t *pgd = p;
1da177e4 LT	230	unsigned long flags;
1da177e4 LT	231
e618c957	232	/* Clear usermode parts of PGD */
5311ab62 JF	233	memset(pgd, 0, USER_PTRS_PER_PGD*sizeof(pgd_t));
	234
	235	spin_lock_irqsave(&pgd_lock, flags);
1da177e4	236
e618c957 JF	237	/* If the pgd points to a shared pagetable level (either the
	238	ptes in non-PAE, or shared PMD in PAE), then just copy the
	239	references from swapper_pg_dir. */
	240	if (PAGETABLE_LEVELS == 2 \|\|
	241	(PAGETABLE_LEVELS == 3 && SHARED_KERNEL_PMD)) {
	242	clone_pgd_range(pgd + USER_PTRS_PER_PGD,
5311ab62 JF	243	swapper_pg_dir + USER_PTRS_PER_PGD,
5311ab62 JF	244	KERNEL_PGD_PTRS);
e618c957 JF	245	paravirt_alloc_pd_clone(__pa(pgd) >> PAGE_SHIFT,
	246	__pa(swapper_pg_dir) >> PAGE_SHIFT,
	247	USER_PTRS_PER_PGD,
	248	KERNEL_PGD_PTRS);
	249	}
5311ab62	250
e618c957 JF	251	/* list required to sync kernel mapping updates */
e618c957 JF	252	if (!SHARED_KERNEL_PMD)
5311ab62	253	pgd_list_add(pgd);
e618c957 JF	254
e618c957 JF	255	spin_unlock_irqrestore(&pgd_lock, flags);
5311ab62	256	}
1da177e4	257
2378569d	258	static void pgd_dtor(void *pgd)
1da177e4 LT	259	{
	260	unsigned long flags; /* can be called from interrupt context */
	261
f1d1a842 CL	262	if (SHARED_KERNEL_PMD)
f1d1a842 CL	263	return;
5311ab62	264
1da177e4 LT	265	spin_lock_irqsave(&pgd_lock, flags);
	266	pgd_list_del(pgd);
	267	spin_unlock_irqrestore(&pgd_lock, flags);
	268	}
	269
8fe3deef JF	270	#ifdef CONFIG_X86_PAE
	271	/*
	272	* Mop up any pmd pages which may still be attached to the pgd.
	273	* Normally they will be freed by munmap/exit_mmap, but any pmd we
	274	* preallocate which never got a corresponding vma will need to be
	275	* freed manually.
	276	*/
5e541973	277	static void pgd_mop_up_pmds(struct mm_struct mm, pgd_t pgdp)
8fe3deef JF	278	{
	279	int i;
	280
508bebbb	281	for(i = 0; i < UNSHARED_PTRS_PER_PGD; i++) {
8fe3deef JF	282	pgd_t pgd = pgdp[i];
	283
	284	if (pgd_val(pgd) != 0) {
	285	pmd_t pmd = (pmd_t )pgd_page_vaddr(pgd);
	286
	287	pgdp[i] = native_make_pgd(0);
	288
	289	paravirt_release_pd(pgd_val(pgd) >> PAGE_SHIFT);
5e541973	290	pmd_free(mm, pmd);
8fe3deef JF	291	}
	292	}
	293	}
	294
	295	/*
	296	* In PAE mode, we need to do a cr3 reload (=tlb flush) when
	297	* updating the top-level pagetable entries to guarantee the
	298	* processor notices the update. Since this is expensive, and
	299	* all 4 top-level entries are used almost immediately in a
	300	* new process's life, we just pre-populate them here.
508bebbb JF	301	*
	302	* Also, if we're in a paravirt environment where the kernel pmd is
	303	* not shared between pagetables (!SHARED_KERNEL_PMDS), we allocate
	304	* and initialize the kernel pmds here.
8fe3deef JF	305	*/
	306	static int pgd_prepopulate_pmd(struct mm_struct mm, pgd_t pgd)
	307	{
	308	pud_t *pud;
	309	unsigned long addr;
	310	int i;
	311
	312	pud = pud_offset(pgd, 0);
508bebbb JF	313	for (addr = i = 0; i < UNSHARED_PTRS_PER_PGD;
508bebbb JF	314	i++, pud++, addr += PUD_SIZE) {
8fe3deef JF	315	pmd_t *pmd = pmd_alloc_one(mm, addr);
	316
	317	if (!pmd) {
5e541973	318	pgd_mop_up_pmds(mm, pgd);
8fe3deef JF	319	return 0;
	320	}
	321
508bebbb JF	322	if (i >= USER_PTRS_PER_PGD)
	323	memcpy(pmd, (pmd_t *)pgd_page_vaddr(swapper_pg_dir[i]),
	324	sizeof(pmd_t) * PTRS_PER_PMD);
	325
8fe3deef JF	326	pud_populate(mm, pud, pmd);
	327	}
	328
	329	return 1;
	330	}
	331	#else /* !CONFIG_X86_PAE */
	332	/* No need to prepopulate any pagetable entries in non-PAE modes. */
	333	static int pgd_prepopulate_pmd(struct mm_struct mm, pgd_t pgd)
	334	{
	335	return 1;
	336	}
	337
5e541973	338	static void pgd_mop_up_pmds(struct mm_struct mm, pgd_t pgdp)
8fe3deef JF	339	{
	340	}
	341	#endif /* CONFIG_X86_PAE */
	342
1da177e4 LT	343	pgd_t pgd_alloc(struct mm_struct mm)
1da177e4 LT	344	{
f1d1a842	345	pgd_t *pgd = quicklist_alloc(0, GFP_KERNEL, pgd_ctor);
1da177e4	346
6c435456 JF	347	mm->pgd = pgd; /* so that alloc_pd can use it */
6c435456 JF	348
8fe3deef JF	349	if (pgd && !pgd_prepopulate_pmd(mm, pgd)) {
	350	quicklist_free(0, pgd_dtor, pgd);
	351	pgd = NULL;
	352	}
	353
1da177e4	354	return pgd;
1da177e4 LT	355	}
1da177e4 LT	356
5e541973	357	void pgd_free(struct mm_struct mm, pgd_t pgd)
1da177e4	358	{
5e541973	359	pgd_mop_up_pmds(mm, pgd);
f1d1a842	360	quicklist_free(0, pgd_dtor, pgd);
1da177e4	361	}
f1d1a842 CL	362
	363	void check_pgt_cache(void)
	364	{
	365	quicklist_trim(0, pgd_dtor, 25, 16);
	366	}
5aa05085 IM	367
	368	void __pte_free_tlb(struct mmu_gather tlb, struct page pte)
	369	{
2f569afd	370	pgtable_page_dtor(pte);
5aa05085 IM	371	paravirt_release_pt(page_to_pfn(pte));
	372	tlb_remove_page(tlb, pte);
	373	}
	374
	375	#ifdef CONFIG_X86_PAE
	376
	377	void __pmd_free_tlb(struct mmu_gather tlb, pmd_t pmd)
	378	{
5aa05085 IM	379	paravirt_release_pd(__pa(pmd) >> PAGE_SHIFT);
	380	tlb_remove_page(tlb, virt_to_page(pmd));
	381	}
	382
	383	#endif