linux/mm/fremap.c
Linus Torvalds 988adfdffd Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux
Pull drm updates from Dave Airlie:
 "Highlights:

   - AMD KFD driver merge

     This is the AMD HSA interface for exposing a lowlevel interface for
     GPGPU use.  They have an open source userspace built on top of this
     interface, and the code looks as good as it was going to get out of
     tree.

   - Initial atomic modesetting work

     The need for an atomic modesetting interface to allow userspace to
     try and send a complete set of modesetting state to the driver has
     arisen, and been suffering from neglect this past year.  No more,
     the start of the common code and changes for msm driver to use it
     are in this tree.  Ongoing work to get the userspace ioctl finished
     and the code clean will probably wait until next kernel.

   - DisplayID 1.3 and tiled monitor exposed to userspace.

     Tiled monitor property is now exposed for userspace to make use of.

   - Rockchip drm driver merged.

   - imx gpu driver moved out of staging

  Other stuff:

   - core:
        panel - MIPI DSI + new panels.
        expose suggested x/y properties for virtual GPUs

   - i915:
        Initial Skylake (SKL) support
        gen3/4 reset work
        start of dri1/ums removal
        infoframe tracking
        fixes for lots of things.

   - nouveau:
        tegra k1 voltage support
        GM204 modesetting support
        GT21x memory reclocking work

   - radeon:
        CI dpm fixes
        GPUVM improvements
        Initial DPM fan control

   - rcar-du:
        HDMI support added
        removed some support for old boards
        slave encoder driver for Analog Devices adv7511

   - exynos:
        Exynos4415 SoC support

   - msm:
        a4xx gpu support
        atomic helper conversion

   - tegra:
        iommu support
        universal plane support
        ganged-mode DSI support

   - sti:
        HDMI i2c improvements

   - vmwgfx:
        some late fixes.

   - qxl:
        use suggested x/y properties"

* 'drm-next' of git://people.freedesktop.org/~airlied/linux: (969 commits)
  drm: sti: fix module compilation issue
  drm/i915: save/restore GMBUS freq across suspend/resume on gen4
  drm: sti: correctly cleanup CRTC and planes
  drm: sti: add HQVDP plane
  drm: sti: add cursor plane
  drm: sti: enable auxiliary CRTC
  drm: sti: fix delay in VTG programming
  drm: sti: prepare sti_tvout to support auxiliary crtc
  drm: sti: use drm_crtc_vblank_{on/off} instead of drm_vblank_{on/off}
  drm: sti: fix hdmi avi infoframe
  drm: sti: remove event lock while disabling vblank
  drm: sti: simplify gdp code
  drm: sti: clear all mixer control
  drm: sti: remove gpio for HDMI hot plug detection
  drm: sti: allow to change hdmi ddc i2c adapter
  drm/doc: Document drm_add_modes_noedid() usage
  drm/i915: Remove '& 0xffff' from the mask given to WA_REG()
  drm/i915: Invert the mask and val arguments in wa_add() and WA_REG()
  drm: Zero out DRM object memory upon cleanup
  drm/i915/bdw: Fix the write setting up the WIZ hashing mode
  ...
2014-12-15 15:52:01 -08:00

284 lines
7.3 KiB
C

/*
* linux/mm/fremap.c
*
* Explicit pagetable population and nonlinear (random) mappings support.
*
* started by Ingo Molnar, Copyright (C) 2002, 2003
*/
#include <linux/export.h>
#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 int mm_counter(struct page *page)
{
return PageAnon(page) ? MM_ANONPAGES : MM_FILEPAGES;
}
static void zap_pte(struct mm_struct *mm, struct vm_area_struct *vma,
unsigned long addr, pte_t *ptep)
{
pte_t pte = *ptep;
struct page *page;
swp_entry_t entry;
if (pte_present(pte)) {
flush_cache_page(vma, addr, pte_pfn(pte));
pte = ptep_clear_flush_notify(vma, addr, ptep);
page = vm_normal_page(vma, addr, pte);
if (page) {
if (pte_dirty(pte))
set_page_dirty(page);
update_hiwater_rss(mm);
dec_mm_counter(mm, mm_counter(page));
page_remove_rmap(page);
page_cache_release(page);
}
} else { /* zap_pte() is not called when pte_none() */
if (!pte_file(pte)) {
update_hiwater_rss(mm);
entry = pte_to_swp_entry(pte);
if (non_swap_entry(entry)) {
if (is_migration_entry(entry)) {
page = migration_entry_to_page(entry);
dec_mm_counter(mm, mm_counter(page));
}
} else {
free_swap_and_cache(entry);
dec_mm_counter(mm, MM_SWAPENTS);
}
}
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, ptfile;
spinlock_t *ptl;
pte = get_locked_pte(mm, addr, &ptl);
if (!pte)
goto out;
ptfile = pgoff_to_pte(pgoff);
if (!pte_none(*pte))
zap_pte(mm, vma, addr, pte);
set_pte_at(mm, addr, pte, pte_file_mksoft_dirty(ptfile));
/*
* 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;
}
int generic_file_remap_pages(struct vm_area_struct *vma, unsigned long addr,
unsigned long size, pgoff_t pgoff)
{
struct mm_struct *mm = vma->vm_mm;
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;
}
EXPORT_SYMBOL(generic_file_remap_pages);
/**
* 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;
vm_flags_t vm_flags = 0;
pr_warn_once("%s (%d) uses deprecated remap_file_pages() syscall. "
"See Documentation/vm/remap_file_pages.txt.\n",
current->comm, current->pid);
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.
*/
if (!vma || !(vma->vm_flags & VM_SHARED))
goto out;
if (!vma->vm_ops || !vma->vm_ops->remap_pages)
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)) {
/*
* vm_private_data is used as a swapout cursor
* in a VM_NONLINEAR vma.
*/
if (vma->vm_private_data)
goto out;
/* Don't need a nonlinear mapping, exit success */
if (pgoff == linear_page_index(vma, start)) {
err = 0;
goto out;
}
if (!has_write_lock) {
get_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 = get_file(vma->vm_file);
/* mmap_region may free vma; grab the info now */
vm_flags = vma->vm_flags;
addr = mmap_region(file, start, size, vm_flags, pgoff);
fput(file);
if (IS_ERR_VALUE(addr)) {
err = addr;
} else {
BUG_ON(addr != start);
err = 0;
}
goto out_freed;
}
i_mmap_lock_write(mapping);
flush_dcache_mmap_lock(mapping);
vma->vm_flags |= VM_NONLINEAR;
vma_interval_tree_remove(vma, &mapping->i_mmap);
vma_nonlinear_insert(vma, &mapping->i_mmap_nonlinear);
flush_dcache_mmap_unlock(mapping);
i_mmap_unlock_write(mapping);
}
if (vma->vm_flags & VM_LOCKED) {
/*
* drop PG_Mlocked flag for over-mapped range
*/
if (!has_write_lock)
goto get_write_lock;
vm_flags = vma->vm_flags;
munlock_vma_pages_range(vma, start, start + size);
vma->vm_flags = vm_flags;
}
mmu_notifier_invalidate_range_start(mm, start, start + size);
err = vma->vm_ops->remap_pages(vma, start, size, pgoff);
mmu_notifier_invalidate_range_end(mm, 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 (vma)
vm_flags = vma->vm_flags;
out_freed:
if (likely(!has_write_lock))
up_read(&mm->mmap_sem);
else
up_write(&mm->mmap_sem);
if (!err && ((vm_flags & VM_LOCKED) || !(flags & MAP_NONBLOCK)))
mm_populate(start, size);
return err;
}