arch/sparc64/mm/hugetlbpage.c - maze/linux - Git at Google

 /*
  * SPARC64 Huge TLB page support.
  *
  * Copyright (C) 2002, 2003, 2006 David S. Miller (davem@davemloft.net)
  */

 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/fs.h>
 #include <linux/mm.h>
 #include <linux/hugetlb.h>
 #include <linux/pagemap.h>
 #include <linux/smp_lock.h>
 #include <linux/slab.h>
 #include <linux/sysctl.h>

 #include <asm/mman.h>
 #include <asm/pgalloc.h>
 #include <asm/tlb.h>
 #include <asm/tlbflush.h>
 #include <asm/cacheflush.h>
 #include <asm/mmu_context.h>

 /* Slightly simplified from the non-hugepage variant because by
  * definition we don't have to worry about any page coloring stuff
  */
 #define VA_EXCLUDE_START (0x0000080000000000UL - (1UL << 32UL))
 #define VA_EXCLUDE_END   (0xfffff80000000000UL + (1UL << 32UL))

 static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *filp,
 							unsigned long addr,
 							unsigned long len,
 							unsigned long pgoff,
 							unsigned long flags)
 {
 	struct mm_struct *mm = current->mm;
 	struct vm_area_struct * vma;
 	unsigned long task_size = TASK_SIZE;
 	unsigned long start_addr;

 	if (test_thread_flag(TIF_32BIT))
 		task_size = STACK_TOP32;
 	if (unlikely(len >= VA_EXCLUDE_START))
 		return -ENOMEM;

 	if (len > mm->cached_hole_size) {
 	        start_addr = addr = mm->free_area_cache;
 	} else {
 	        start_addr = addr = TASK_UNMAPPED_BASE;
 	        mm->cached_hole_size = 0;
 	}

 	task_size -= len;

 full_search:
 	addr = ALIGN(addr, HPAGE_SIZE);

 	for (vma = find_vma(mm, addr); ; vma = vma->vm_next) {
 		/* At this point:  (!vma || addr < vma->vm_end). */
 		if (addr < VA_EXCLUDE_START &&
 		    (addr + len) >= VA_EXCLUDE_START) {
 			addr = VA_EXCLUDE_END;
 			vma = find_vma(mm, VA_EXCLUDE_END);
 		}
 		if (unlikely(task_size < addr)) {
 			if (start_addr != TASK_UNMAPPED_BASE) {
 				start_addr = addr = TASK_UNMAPPED_BASE;
 				mm->cached_hole_size = 0;
 				goto full_search;
 			}
 			return -ENOMEM;
 		}
 		if (likely(!vma || addr + len <= vma->vm_start)) {
 			/*
 			 * Remember the place where we stopped the search:
 			 */
 			mm->free_area_cache = addr + len;
 			return addr;
 		}
 		if (addr + mm->cached_hole_size < vma->vm_start)
 		        mm->cached_hole_size = vma->vm_start - addr;

 		addr = ALIGN(vma->vm_end, HPAGE_SIZE);
 	}
 }

 static unsigned long
 hugetlb_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
 				  const unsigned long len,
 				  const unsigned long pgoff,
 				  const unsigned long flags)
 {
 	struct vm_area_struct *vma;
 	struct mm_struct *mm = current->mm;
 	unsigned long addr = addr0;

 	/* This should only ever run for 32-bit processes.  */
 	BUG_ON(!test_thread_flag(TIF_32BIT));

 	/* check if free_area_cache is useful for us */
 	if (len <= mm->cached_hole_size) {
  	        mm->cached_hole_size = 0;
  		mm->free_area_cache = mm->mmap_base;
  	}

 	/* either no address requested or can't fit in requested address hole */
 	addr = mm->free_area_cache & HPAGE_MASK;

 	/* make sure it can fit in the remaining address space */
 	if (likely(addr > len)) {
 		vma = find_vma(mm, addr-len);
 		if (!vma || addr <= vma->vm_start) {
 			/* remember the address as a hint for next time */
 			return (mm->free_area_cache = addr-len);
 		}
 	}

 	if (unlikely(mm->mmap_base < len))
 		goto bottomup;

 	addr = (mm->mmap_base-len) & HPAGE_MASK;

 	do {
 		/*
 		 * Lookup failure means no vma is above this address,
 		 * else if new region fits below vma->vm_start,
 		 * return with success:
 		 */
 		vma = find_vma(mm, addr);
 		if (likely(!vma || addr+len <= vma->vm_start)) {
 			/* remember the address as a hint for next time */
 			return (mm->free_area_cache = addr);
 		}

  		/* remember the largest hole we saw so far */
  		if (addr + mm->cached_hole_size < vma->vm_start)
  		        mm->cached_hole_size = vma->vm_start - addr;

 		/* try just below the current vma->vm_start */
 		addr = (vma->vm_start-len) & HPAGE_MASK;
 	} while (likely(len < vma->vm_start));

 bottomup:
 	/*
 	 * A failed mmap() very likely causes application failure,
 	 * so fall back to the bottom-up function here. This scenario
 	 * can happen with large stack limits and large mmap()
 	 * allocations.
 	 */
 	mm->cached_hole_size = ~0UL;
   	mm->free_area_cache = TASK_UNMAPPED_BASE;
 	addr = arch_get_unmapped_area(filp, addr0, len, pgoff, flags);
 	/*
 	 * Restore the topdown base:
 	 */
 	mm->free_area_cache = mm->mmap_base;
 	mm->cached_hole_size = ~0UL;

 	return addr;
 }

 unsigned long
 hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
 		unsigned long len, unsigned long pgoff, unsigned long flags)
 {
 	struct mm_struct *mm = current->mm;
 	struct vm_area_struct *vma;
 	unsigned long task_size = TASK_SIZE;

 	if (test_thread_flag(TIF_32BIT))
 		task_size = STACK_TOP32;

 	if (len & ~HPAGE_MASK)
 		return -EINVAL;
 	if (len > task_size)
 		return -ENOMEM;

 	if (addr) {
 		addr = ALIGN(addr, HPAGE_SIZE);
 		vma = find_vma(mm, addr);
 		if (task_size - len >= addr &&
 		    (!vma || addr + len <= vma->vm_start))
 			return addr;
 	}
 	if (mm->get_unmapped_area == arch_get_unmapped_area)
 		return hugetlb_get_unmapped_area_bottomup(file, addr, len,
 				pgoff, flags);
 	else
 		return hugetlb_get_unmapped_area_topdown(file, addr, len,
 				pgoff, flags);
 }

 pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr)
 {
 	pgd_t *pgd;
 	pud_t *pud;
 	pmd_t *pmd;
 	pte_t *pte = NULL;

 	/* We must align the address, because our caller will run
 	 * set_huge_pte_at() on whatever we return, which writes out
 	 * all of the sub-ptes for the hugepage range.  So we have
 	 * to give it the first such sub-pte.
 	 */
 	addr &= HPAGE_MASK;

 	pgd = pgd_offset(mm, addr);
 	pud = pud_alloc(mm, pgd, addr);
 	if (pud) {
 		pmd = pmd_alloc(mm, pud, addr);
 		if (pmd)
 			pte = pte_alloc_map(mm, pmd, addr);
 	}
 	return pte;
 }

 pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
 {
 	pgd_t *pgd;
 	pud_t *pud;
 	pmd_t *pmd;
 	pte_t *pte = NULL;

 	addr &= HPAGE_MASK;

 	pgd = pgd_offset(mm, addr);
 	if (!pgd_none(*pgd)) {
 		pud = pud_offset(pgd, addr);
 		if (!pud_none(*pud)) {
 			pmd = pmd_offset(pud, addr);
 			if (!pmd_none(*pmd))
 				pte = pte_offset_map(pmd, addr);
 		}
 	}
 	return pte;
 }

 int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep)
 {
 	return 0;
 }

 void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
 		     pte_t *ptep, pte_t entry)
 {
 	int i;

 	if (!pte_present(*ptep) && pte_present(entry))
 		mm->context.huge_pte_count++;

 	addr &= HPAGE_MASK;
 	for (i = 0; i < (1 << HUGETLB_PAGE_ORDER); i++) {
 		set_pte_at(mm, addr, ptep, entry);
 		ptep++;
 		addr += PAGE_SIZE;
 		pte_val(entry) += PAGE_SIZE;
 	}
 }

 pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
 			      pte_t *ptep)
 {
 	pte_t entry;
 	int i;

 	entry = *ptep;
 	if (pte_present(entry))
 		mm->context.huge_pte_count--;

 	addr &= HPAGE_MASK;

 	for (i = 0; i < (1 << HUGETLB_PAGE_ORDER); i++) {
 		pte_clear(mm, addr, ptep);
 		addr += PAGE_SIZE;
 		ptep++;
 	}

 	return entry;
 }

 struct page *follow_huge_addr(struct mm_struct *mm,
 			      unsigned long address, int write)
 {
 	return ERR_PTR(-EINVAL);
 }

 int pmd_huge(pmd_t pmd)
 {
 	return 0;
 }

 struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address,
 			     pmd_t *pmd, int write)
 {
 	return NULL;
 }

 static void context_reload(void *__data)
 {
 	struct mm_struct *mm = __data;

 	if (mm == current->mm)
 		load_secondary_context(mm);
 }

 void hugetlb_prefault_arch_hook(struct mm_struct *mm)
 {
 	struct tsb_config *tp = &mm->context.tsb_block[MM_TSB_HUGE];

 	if (likely(tp->tsb != NULL))
 		return;

 	tsb_grow(mm, MM_TSB_HUGE, 0);
 	tsb_context_switch(mm);
 	smp_tsb_sync(mm);

 	/* On UltraSPARC-III+ and later, configure the second half of
 	 * the Data-TLB for huge pages.
 	 */
 	if (tlb_type == cheetah_plus) {
 		unsigned long ctx;

 		spin_lock(&ctx_alloc_lock);
 		ctx = mm->context.sparc64_ctx_val;
 		ctx &= ~CTX_PGSZ_MASK;
 		ctx |= CTX_PGSZ_BASE << CTX_PGSZ0_SHIFT;
 		ctx |= CTX_PGSZ_HUGE << CTX_PGSZ1_SHIFT;

 		if (ctx != mm->context.sparc64_ctx_val) {
 			/* When changing the page size fields, we
 			 * must perform a context flush so that no
 			 * stale entries match.  This flush must
 			 * occur with the original context register
 			 * settings.
 			 */
 			do_flush_tlb_mm(mm);

 			/* Reload the context register of all processors
 			 * also executing in this address space.
 			 */
 			mm->context.sparc64_ctx_val = ctx;
 			on_each_cpu(context_reload, mm, 0, 0);
 		}
 		spin_unlock(&ctx_alloc_lock);
 	}
 }
	/*
	* SPARC64 Huge TLB page support.
	*
	* Copyright (C) 2002, 2003, 2006 David S. Miller (davem@davemloft.net)
	*/

	#include <linux/init.h>
	#include <linux/module.h>
	#include <linux/fs.h>
	#include <linux/mm.h>
	#include <linux/hugetlb.h>
	#include <linux/pagemap.h>
	#include <linux/smp_lock.h>
	#include <linux/slab.h>
	#include <linux/sysctl.h>

	#include <asm/mman.h>
	#include <asm/pgalloc.h>
	#include <asm/tlb.h>
	#include <asm/tlbflush.h>
	#include <asm/cacheflush.h>
	#include <asm/mmu_context.h>

	/* Slightly simplified from the non-hugepage variant because by
	* definition we don't have to worry about any page coloring stuff
	*/
	#define VA_EXCLUDE_START (0x0000080000000000UL - (1UL << 32UL))
	#define VA_EXCLUDE_END (0xfffff80000000000UL + (1UL << 32UL))

	static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *filp,
	unsigned long addr,
	unsigned long len,
	unsigned long pgoff,
	unsigned long flags)
	{
	struct mm_struct *mm = current->mm;
	struct vm_area_struct * vma;
	unsigned long task_size = TASK_SIZE;
	unsigned long start_addr;

	if (test_thread_flag(TIF_32BIT))
	task_size = STACK_TOP32;
	if (unlikely(len >= VA_EXCLUDE_START))
	return -ENOMEM;

	if (len > mm->cached_hole_size) {
	start_addr = addr = mm->free_area_cache;
	} else {
	start_addr = addr = TASK_UNMAPPED_BASE;
	mm->cached_hole_size = 0;
	}

	task_size -= len;

	full_search:
	addr = ALIGN(addr, HPAGE_SIZE);

	for (vma = find_vma(mm, addr); ; vma = vma->vm_next) {
	/* At this point: (!vma \|\| addr < vma->vm_end). */
	if (addr < VA_EXCLUDE_START &&
	(addr + len) >= VA_EXCLUDE_START) {
	addr = VA_EXCLUDE_END;
	vma = find_vma(mm, VA_EXCLUDE_END);
	}
	if (unlikely(task_size < addr)) {
	if (start_addr != TASK_UNMAPPED_BASE) {
	start_addr = addr = TASK_UNMAPPED_BASE;
	mm->cached_hole_size = 0;
	goto full_search;
	}
	return -ENOMEM;
	}
	if (likely(!vma \|\| addr + len <= vma->vm_start)) {
	/*
	* Remember the place where we stopped the search:
	*/
	mm->free_area_cache = addr + len;
	return addr;
	}
	if (addr + mm->cached_hole_size < vma->vm_start)
	mm->cached_hole_size = vma->vm_start - addr;

	addr = ALIGN(vma->vm_end, HPAGE_SIZE);
	}
	}

	static unsigned long
	hugetlb_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
	const unsigned long len,
	const unsigned long pgoff,
	const unsigned long flags)
	{
	struct vm_area_struct *vma;
	struct mm_struct *mm = current->mm;
	unsigned long addr = addr0;

	/* This should only ever run for 32-bit processes. */
	BUG_ON(!test_thread_flag(TIF_32BIT));

	/* check if free_area_cache is useful for us */
	if (len <= mm->cached_hole_size) {
	mm->cached_hole_size = 0;
	mm->free_area_cache = mm->mmap_base;
	}

	/* either no address requested or can't fit in requested address hole */
	addr = mm->free_area_cache & HPAGE_MASK;

	/* make sure it can fit in the remaining address space */
	if (likely(addr > len)) {
	vma = find_vma(mm, addr-len);
	if (!vma \|\| addr <= vma->vm_start) {
	/* remember the address as a hint for next time */
	return (mm->free_area_cache = addr-len);
	}
	}

	if (unlikely(mm->mmap_base < len))
	goto bottomup;

	addr = (mm->mmap_base-len) & HPAGE_MASK;

	do {
	/*
	* Lookup failure means no vma is above this address,
	* else if new region fits below vma->vm_start,
	* return with success:
	*/
	vma = find_vma(mm, addr);
	if (likely(!vma \|\| addr+len <= vma->vm_start)) {
	/* remember the address as a hint for next time */
	return (mm->free_area_cache = addr);
	}

	/* remember the largest hole we saw so far */
	if (addr + mm->cached_hole_size < vma->vm_start)
	mm->cached_hole_size = vma->vm_start - addr;

	/* try just below the current vma->vm_start */
	addr = (vma->vm_start-len) & HPAGE_MASK;
	} while (likely(len < vma->vm_start));

	bottomup:
	/*
	* A failed mmap() very likely causes application failure,
	* so fall back to the bottom-up function here. This scenario
	* can happen with large stack limits and large mmap()
	* allocations.
	*/
	mm->cached_hole_size = ~0UL;
	mm->free_area_cache = TASK_UNMAPPED_BASE;
	addr = arch_get_unmapped_area(filp, addr0, len, pgoff, flags);
	/*
	* Restore the topdown base:
	*/
	mm->free_area_cache = mm->mmap_base;
	mm->cached_hole_size = ~0UL;

	return addr;
	}

	unsigned long
	hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
	unsigned long len, unsigned long pgoff, unsigned long flags)
	{
	struct mm_struct *mm = current->mm;
	struct vm_area_struct *vma;
	unsigned long task_size = TASK_SIZE;

	if (test_thread_flag(TIF_32BIT))
	task_size = STACK_TOP32;

	if (len & ~HPAGE_MASK)
	return -EINVAL;
	if (len > task_size)
	return -ENOMEM;

	if (addr) {
	addr = ALIGN(addr, HPAGE_SIZE);
	vma = find_vma(mm, addr);
	if (task_size - len >= addr &&
	(!vma \|\| addr + len <= vma->vm_start))
	return addr;
	}
	if (mm->get_unmapped_area == arch_get_unmapped_area)
	return hugetlb_get_unmapped_area_bottomup(file, addr, len,
	pgoff, flags);
	else
	return hugetlb_get_unmapped_area_topdown(file, addr, len,
	pgoff, flags);
	}

	pte_t huge_pte_alloc(struct mm_struct mm, unsigned long addr)
	{
	pgd_t *pgd;
	pud_t *pud;
	pmd_t *pmd;
	pte_t *pte = NULL;

	/* We must align the address, because our caller will run
	* set_huge_pte_at() on whatever we return, which writes out
	* all of the sub-ptes for the hugepage range. So we have
	* to give it the first such sub-pte.
	*/
	addr &= HPAGE_MASK;

	pgd = pgd_offset(mm, addr);
	pud = pud_alloc(mm, pgd, addr);
	if (pud) {
	pmd = pmd_alloc(mm, pud, addr);
	if (pmd)
	pte = pte_alloc_map(mm, pmd, addr);
	}
	return pte;
	}

	pte_t huge_pte_offset(struct mm_struct mm, unsigned long addr)
	{
	pgd_t *pgd;
	pud_t *pud;
	pmd_t *pmd;
	pte_t *pte = NULL;

	addr &= HPAGE_MASK;

	pgd = pgd_offset(mm, addr);
	if (!pgd_none(*pgd)) {
	pud = pud_offset(pgd, addr);
	if (!pud_none(*pud)) {
	pmd = pmd_offset(pud, addr);
	if (!pmd_none(*pmd))
	pte = pte_offset_map(pmd, addr);
	}
	}
	return pte;
	}

	int huge_pmd_unshare(struct mm_struct mm, unsigned long addr, pte_t *ptep)
	{
	return 0;
	}

	void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
	pte_t *ptep, pte_t entry)
	{
	int i;

	if (!pte_present(*ptep) && pte_present(entry))
	mm->context.huge_pte_count++;

	addr &= HPAGE_MASK;
	for (i = 0; i < (1 << HUGETLB_PAGE_ORDER); i++) {
	set_pte_at(mm, addr, ptep, entry);
	ptep++;
	addr += PAGE_SIZE;
	pte_val(entry) += PAGE_SIZE;
	}
	}

	pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
	pte_t *ptep)
	{
	pte_t entry;
	int i;

	entry = *ptep;
	if (pte_present(entry))
	mm->context.huge_pte_count--;

	addr &= HPAGE_MASK;

	for (i = 0; i < (1 << HUGETLB_PAGE_ORDER); i++) {
	pte_clear(mm, addr, ptep);
	addr += PAGE_SIZE;
	ptep++;
	}

	return entry;
	}

	struct page follow_huge_addr(struct mm_struct mm,
	unsigned long address, int write)
	{
	return ERR_PTR(-EINVAL);
	}

	int pmd_huge(pmd_t pmd)
	{
	return 0;
	}

	struct page follow_huge_pmd(struct mm_struct mm, unsigned long address,
	pmd_t *pmd, int write)
	{
	return NULL;
	}

	static void context_reload(void *__data)
	{
	struct mm_struct *mm = __data;

	if (mm == current->mm)
	load_secondary_context(mm);
	}

	void hugetlb_prefault_arch_hook(struct mm_struct *mm)
	{
	struct tsb_config *tp = &mm->context.tsb_block[MM_TSB_HUGE];

	if (likely(tp->tsb != NULL))
	return;

	tsb_grow(mm, MM_TSB_HUGE, 0);
	tsb_context_switch(mm);
	smp_tsb_sync(mm);

	/* On UltraSPARC-III+ and later, configure the second half of
	* the Data-TLB for huge pages.
	*/
	if (tlb_type == cheetah_plus) {
	unsigned long ctx;

	spin_lock(&ctx_alloc_lock);
	ctx = mm->context.sparc64_ctx_val;
	ctx &= ~CTX_PGSZ_MASK;
	ctx \|= CTX_PGSZ_BASE << CTX_PGSZ0_SHIFT;
	ctx \|= CTX_PGSZ_HUGE << CTX_PGSZ1_SHIFT;

	if (ctx != mm->context.sparc64_ctx_val) {
	/* When changing the page size fields, we
	* must perform a context flush so that no
	* stale entries match. This flush must
	* occur with the original context register
	* settings.
	*/
	do_flush_tlb_mm(mm);

	/* Reload the context register of all processors
	* also executing in this address space.
	*/
	mm->context.sparc64_ctx_val = ctx;
	on_each_cpu(context_reload, mm, 0, 0);
	}
	spin_unlock(&ctx_alloc_lock);
	}
	}