Commit 5bba49f5 authored by Vineet Gupta's avatar Vineet Gupta

ARC: [mm] Aliasing VIPT dcache support 4/4

Enforce congruency of userspace shared mappings
Signed-off-by: default avatarVineet Gupta <vgupta@synopsys.com>
parent de2a852c
......@@ -32,7 +32,6 @@ generic-y += resource.h
generic-y += scatterlist.h
generic-y += sembuf.h
generic-y += shmbuf.h
generic-y += shmparam.h
generic-y += siginfo.h
generic-y += socket.h
generic-y += sockios.h
......
......@@ -55,9 +55,6 @@
: "r"(data), "r"(ptr)); \
})
/* used to give SHMLBA a value to avoid Cache Aliasing */
extern unsigned int ARC_shmlba;
#define ARCH_DMA_MINALIGN L1_CACHE_BYTES
/*
......
......@@ -19,6 +19,7 @@
#define _ASM_CACHEFLUSH_H
#include <linux/mm.h>
#include <asm/shmparam.h>
/*
* Semantically we need this because icache doesn't snoop dcache/dma.
......
......@@ -395,6 +395,9 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
#include <asm-generic/pgtable.h>
/* to cope with aliasing VIPT cache */
#define HAVE_ARCH_UNMAPPED_AREA
/*
* No page table caches to initialise
*/
......
/*
* Copyright (C) 2013 Synopsys, Inc. (www.synopsys.com)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#ifndef __ARC_ASM_SHMPARAM_H
#define __ARC_ASM_SHMPARAM_H
/* Handle upto 2 cache bins */
#define SHMLBA (2 * PAGE_SIZE)
/* Enforce SHMLBA in shmat */
#define __ARCH_FORCE_SHMLBA
#endif
......@@ -7,4 +7,4 @@
#
obj-y := extable.o ioremap.o dma.o fault.o init.o
obj-y += tlb.o tlbex.o cache_arc700.o
obj-y += tlb.o tlbex.o cache_arc700.o mmap.o
/*
* ARC700 mmap
*
* (started from arm version - for VIPT alias handling)
*
* Copyright (C) 2013 Synopsys, Inc. (www.synopsys.com)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/mman.h>
#include <linux/sched.h>
#include <asm/cacheflush.h>
#define COLOUR_ALIGN(addr, pgoff) \
((((addr) + SHMLBA - 1) & ~(SHMLBA - 1)) + \
(((pgoff) << PAGE_SHIFT) & (SHMLBA - 1)))
/*
* 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.
*/
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;
int aliasing = cache_is_vipt_aliasing();
struct vm_unmapped_area_info info;
/*
* We only need to do colour alignment if D cache aliases.
*/
if (aliasing)
do_align = filp || (flags & MAP_SHARED);
/*
* We enforce the MAP_FIXED case.
*/
if (flags & MAP_FIXED) {
if (aliasing && 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 <= vma->vm_start))
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);
}
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