72 lines
1.7 KiB
C
72 lines
1.7 KiB
C
|
// SPDX-License-Identifier: GPL-2.0
|
||
|
|
// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
|
||
|
|
|
||
|
|
#include <linux/fs.h>
|
||
|
|
#include <linux/mm.h>
|
||
|
|
#include <linux/mman.h>
|
||
|
|
#include <linux/shm.h>
|
||
|
|
#include <linux/sched.h>
|
||
|
|
#include <linux/random.h>
|
||
|
|
#include <linux/io.h>
|
||
|
|
|
||
|
|
#define COLOUR_ALIGN(addr,pgoff) \
|
||
|
|
((((addr)+SHMLBA-1)&~(SHMLBA-1)) + \
|
||
|
|
(((pgoff)<<PAGE_SHIFT) & (SHMLBA-1)))
|
||
|
|
|
||
|
|
/*
|
||
|
|
* We need to ensure that shared mappings are correctly aligned to
|
||
|
|
* avoid aliasing issues with VIPT caches. We need to ensure that
|
||
|
|
* a specific page of an object is always mapped at a multiple of
|
||
|
|
* SHMLBA bytes.
|
||
|
|
*
|
||
|
|
* We unconditionally provide this function for all cases.
|
||
|
|
*/
|
||
|
|
unsigned long
|
||
|
|
arch_get_unmapped_area(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;
|
||
|
|
int do_align = 0;
|
||
|
|
struct vm_unmapped_area_info info;
|
||
|
|
|
||
|
|
/*
|
||
|
|
* We only need to do colour alignment if either the I or D
|
||
|
|
* caches alias.
|
||
|
|
*/
|
||
|
|
do_align = filp || (flags & MAP_SHARED);
|
||
|
|
|
||
|
|
/*
|
||
|
|
* We enforce the MAP_FIXED case.
|
||
|
|
*/
|
||
|
|
if (flags & MAP_FIXED) {
|
||
|
|
if (flags & MAP_SHARED &&
|
||
|
|
(addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1))
|
||
|
|
return -EINVAL;
|
||
|
|
return addr;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (len > TASK_SIZE)
|
||
|
|
return -ENOMEM;
|
||
|
|
|
||
|
|
if (addr) {
|
||
|
|
if (do_align)
|
||
|
|
addr = COLOUR_ALIGN(addr, pgoff);
|
||
|
|
else
|
||
|
|
addr = PAGE_ALIGN(addr);
|
||
|
|
|
||
|
|
vma = find_vma(mm, addr);
|
||
|
|
if (TASK_SIZE - len >= addr &&
|
||
|
|
(!vma || addr + len <= vm_start_gap(vma)))
|
||
|
|
return addr;
|
||
|
|
}
|
||
|
|
|
||
|
|
info.flags = 0;
|
||
|
|
info.length = len;
|
||
|
|
info.low_limit = mm->mmap_base;
|
||
|
|
info.high_limit = TASK_SIZE;
|
||
|
|
info.align_mask = do_align ? (PAGE_MASK & (SHMLBA - 1)) : 0;
|
||
|
|
info.align_offset = pgoff << PAGE_SHIFT;
|
||
|
|
return vm_unmapped_area(&info);
|
||
|
|
}
|