linux/arch/csky/abiv1/mmap.c
Guo Ren 013de2d667 csky: MMU and page table management
This patch adds files related to memory management and here is our
memory-layout:

   Fixmap       : 0xffc02000 – 0xfffff000       (4 MB - 12KB)
   Pkmap        : 0xff800000 – 0xffc00000       (4 MB)
   Vmalloc      : 0xf0200000 – 0xff000000       (238 MB)
   Lowmem       : 0x80000000 – 0xc0000000       (1GB)

abiv1 CPU (CK610) is VIPT cache and it doesn't support highmem.
abiv2 CPUs are all PIPT cache and they could support highmem.

Lowmem is directly mapped by msa0 & msa1 reg, and we needn't setup
memory page table for it.

Link:https://lore.kernel.org/lkml/20180518215548.GH17671@n2100.armlinux.org.uk/
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Cc: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
2018-10-25 23:36:19 +08:00

67 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>
unsigned long shm_align_mask = (0x4000 >> 1) - 1; /* Sane caches */
#define COLOUR_ALIGN(addr, pgoff) \
((((addr) + shm_align_mask) & ~shm_align_mask) + \
(((pgoff) << PAGE_SHIFT) & shm_align_mask))
unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
unsigned long len, unsigned long pgoff, unsigned long flags)
{
struct vm_area_struct *vmm;
int do_color_align;
if (flags & MAP_FIXED) {
/*
* We do not accept a shared mapping if it would violate
* cache aliasing constraints.
*/
if ((flags & MAP_SHARED) &&
((addr - (pgoff << PAGE_SHIFT)) & shm_align_mask))
return -EINVAL;
return addr;
}
if (len > TASK_SIZE)
return -ENOMEM;
do_color_align = 0;
if (filp || (flags & MAP_SHARED))
do_color_align = 1;
if (addr) {
if (do_color_align)
addr = COLOUR_ALIGN(addr, pgoff);
else
addr = PAGE_ALIGN(addr);
vmm = find_vma(current->mm, addr);
if (TASK_SIZE - len >= addr &&
(!vmm || addr + len <= vmm->vm_start))
return addr;
}
addr = TASK_UNMAPPED_BASE;
if (do_color_align)
addr = COLOUR_ALIGN(addr, pgoff);
else
addr = PAGE_ALIGN(addr);
for (vmm = find_vma(current->mm, addr); ; vmm = vmm->vm_next) {
/* At this point: (!vmm || addr < vmm->vm_end). */
if (TASK_SIZE - len < addr)
return -ENOMEM;
if (!vmm || addr + len <= vmm->vm_start)
return addr;
addr = vmm->vm_end;
if (do_color_align)
addr = COLOUR_ALIGN(addr, pgoff);
}
}