[T106][ZXW-22]7520V3SCV2.01.01.02P42U09_VEC_V0.8_AP_VEC origin source commit
Change-Id: Ic6e05d89ecd62fc34f82b23dcf306c93764aec4b
diff --git a/ap/os/linux/linux-3.4.x/mm/fremap.c b/ap/os/linux/linux-3.4.x/mm/fremap.c
new file mode 100644
index 0000000..9ed4fd4
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/fremap.c
@@ -0,0 +1,262 @@
+/*
+ * linux/mm/fremap.c
+ *
+ * Explicit pagetable population and nonlinear (random) mappings support.
+ *
+ * started by Ingo Molnar, Copyright (C) 2002, 2003
+ */
+#include <linux/backing-dev.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/file.h>
+#include <linux/mman.h>
+#include <linux/pagemap.h>
+#include <linux/swapops.h>
+#include <linux/rmap.h>
+#include <linux/syscalls.h>
+#include <linux/mmu_notifier.h>
+
+#include <asm/mmu_context.h>
+#include <asm/cacheflush.h>
+#include <asm/tlbflush.h>
+
+#include "internal.h"
+
+static void zap_pte(struct mm_struct *mm, struct vm_area_struct *vma,
+ unsigned long addr, pte_t *ptep)
+{
+ pte_t pte = *ptep;
+
+ if (pte_present(pte)) {
+ struct page *page;
+
+ flush_cache_page(vma, addr, pte_pfn(pte));
+ pte = ptep_clear_flush(vma, addr, ptep);
+ page = vm_normal_page(vma, addr, pte);
+ if (page) {
+ if (pte_dirty(pte))
+ set_page_dirty(page);
+ page_remove_rmap(page);
+ page_cache_release(page);
+ update_hiwater_rss(mm);
+ dec_mm_counter(mm, MM_FILEPAGES);
+ }
+ } else {
+ if (!pte_file(pte))
+ free_swap_and_cache(pte_to_swp_entry(pte));
+ pte_clear_not_present_full(mm, addr, ptep, 0);
+ }
+}
+
+/*
+ * Install a file pte to a given virtual memory address, release any
+ * previously existing mapping.
+ */
+static int install_file_pte(struct mm_struct *mm, struct vm_area_struct *vma,
+ unsigned long addr, unsigned long pgoff, pgprot_t prot)
+{
+ int err = -ENOMEM;
+ pte_t *pte;
+ spinlock_t *ptl;
+
+ pte = get_locked_pte(mm, addr, &ptl);
+ if (!pte)
+ goto out;
+
+ if (!pte_none(*pte))
+ zap_pte(mm, vma, addr, pte);
+
+ set_pte_at(mm, addr, pte, pgoff_to_pte(pgoff));
+ /*
+ * We don't need to run update_mmu_cache() here because the "file pte"
+ * being installed by install_file_pte() is not a real pte - it's a
+ * non-present entry (like a swap entry), noting what file offset should
+ * be mapped there when there's a fault (in a non-linear vma where
+ * that's not obvious).
+ */
+ pte_unmap_unlock(pte, ptl);
+ err = 0;
+out:
+ return err;
+}
+
+static int populate_range(struct mm_struct *mm, struct vm_area_struct *vma,
+ unsigned long addr, unsigned long size, pgoff_t pgoff)
+{
+ int err;
+
+ do {
+ err = install_file_pte(mm, vma, addr, pgoff, vma->vm_page_prot);
+ if (err)
+ return err;
+
+ size -= PAGE_SIZE;
+ addr += PAGE_SIZE;
+ pgoff++;
+ } while (size);
+
+ return 0;
+
+}
+
+/**
+ * sys_remap_file_pages - remap arbitrary pages of an existing VM_SHARED vma
+ * @start: start of the remapped virtual memory range
+ * @size: size of the remapped virtual memory range
+ * @prot: new protection bits of the range (see NOTE)
+ * @pgoff: to-be-mapped page of the backing store file
+ * @flags: 0 or MAP_NONBLOCKED - the later will cause no IO.
+ *
+ * sys_remap_file_pages remaps arbitrary pages of an existing VM_SHARED vma
+ * (shared backing store file).
+ *
+ * This syscall works purely via pagetables, so it's the most efficient
+ * way to map the same (large) file into a given virtual window. Unlike
+ * mmap()/mremap() it does not create any new vmas. The new mappings are
+ * also safe across swapout.
+ *
+ * NOTE: the @prot parameter right now is ignored (but must be zero),
+ * and the vma's default protection is used. Arbitrary protections
+ * might be implemented in the future.
+ */
+SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
+ unsigned long, prot, unsigned long, pgoff, unsigned long, flags)
+{
+ struct mm_struct *mm = current->mm;
+ struct address_space *mapping;
+ struct vm_area_struct *vma;
+ int err = -EINVAL;
+ int has_write_lock = 0;
+
+ if (prot)
+ return err;
+ /*
+ * Sanitize the syscall parameters:
+ */
+ start = start & PAGE_MASK;
+ size = size & PAGE_MASK;
+
+ /* Does the address range wrap, or is the span zero-sized? */
+ if (start + size <= start)
+ return err;
+
+ /* Does pgoff wrap? */
+ if (pgoff + (size >> PAGE_SHIFT) < pgoff)
+ return err;
+
+ /* Can we represent this offset inside this architecture's pte's? */
+#if PTE_FILE_MAX_BITS < BITS_PER_LONG
+ if (pgoff + (size >> PAGE_SHIFT) >= (1UL << PTE_FILE_MAX_BITS))
+ return err;
+#endif
+
+ /* We need down_write() to change vma->vm_flags. */
+ down_read(&mm->mmap_sem);
+ retry:
+ vma = find_vma(mm, start);
+
+ /*
+ * Make sure the vma is shared, that it supports prefaulting,
+ * and that the remapped range is valid and fully within
+ * the single existing vma. vm_private_data is used as a
+ * swapout cursor in a VM_NONLINEAR vma.
+ */
+ if (!vma || !(vma->vm_flags & VM_SHARED))
+ goto out;
+
+ if (vma->vm_private_data && !(vma->vm_flags & VM_NONLINEAR))
+ goto out;
+
+ if (!(vma->vm_flags & VM_CAN_NONLINEAR))
+ goto out;
+
+ if (start < vma->vm_start || start + size > vma->vm_end)
+ goto out;
+
+ /* Must set VM_NONLINEAR before any pages are populated. */
+ if (!(vma->vm_flags & VM_NONLINEAR)) {
+ /* Don't need a nonlinear mapping, exit success */
+ if (pgoff == linear_page_index(vma, start)) {
+ err = 0;
+ goto out;
+ }
+
+ if (!has_write_lock) {
+ up_read(&mm->mmap_sem);
+ down_write(&mm->mmap_sem);
+ has_write_lock = 1;
+ goto retry;
+ }
+ mapping = vma->vm_file->f_mapping;
+ /*
+ * page_mkclean doesn't work on nonlinear vmas, so if
+ * dirty pages need to be accounted, emulate with linear
+ * vmas.
+ */
+ if (mapping_cap_account_dirty(mapping)) {
+ unsigned long addr;
+ struct file *file = vma->vm_file;
+
+ flags &= MAP_NONBLOCK;
+ get_file(file);
+ addr = mmap_region(file, start, size,
+ flags, vma->vm_flags, pgoff);
+ fput(file);
+ if (IS_ERR_VALUE(addr)) {
+ err = addr;
+ } else {
+ BUG_ON(addr != start);
+ err = 0;
+ }
+ goto out;
+ }
+ mutex_lock(&mapping->i_mmap_mutex);
+ flush_dcache_mmap_lock(mapping);
+ vma->vm_flags |= VM_NONLINEAR;
+ vma_prio_tree_remove(vma, &mapping->i_mmap);
+ vma_nonlinear_insert(vma, &mapping->i_mmap_nonlinear);
+ flush_dcache_mmap_unlock(mapping);
+ mutex_unlock(&mapping->i_mmap_mutex);
+ }
+
+ if (vma->vm_flags & VM_LOCKED) {
+ /*
+ * drop PG_Mlocked flag for over-mapped range
+ */
+ vm_flags_t saved_flags = vma->vm_flags;
+ munlock_vma_pages_range(vma, start, start + size);
+ vma->vm_flags = saved_flags;
+ }
+
+ mmu_notifier_invalidate_range_start(mm, start, start + size);
+ err = populate_range(mm, vma, start, size, pgoff);
+ mmu_notifier_invalidate_range_end(mm, start, start + size);
+ if (!err && !(flags & MAP_NONBLOCK)) {
+ if (vma->vm_flags & VM_LOCKED) {
+ /*
+ * might be mapping previously unmapped range of file
+ */
+ mlock_vma_pages_range(vma, start, start + size);
+ } else {
+ if (unlikely(has_write_lock)) {
+ downgrade_write(&mm->mmap_sem);
+ has_write_lock = 0;
+ }
+ make_pages_present(start, start+size);
+ }
+ }
+
+ /*
+ * We can't clear VM_NONLINEAR because we'd have to do
+ * it after ->populate completes, and that would prevent
+ * downgrading the lock. (Locks can't be upgraded).
+ */
+
+out:
+ if (likely(!has_write_lock))
+ up_read(&mm->mmap_sem);
+ else
+ up_write(&mm->mmap_sem);
+
+ return err;
+}