mmu-context.c revision 492e675116003b99dfcf0fa70084027e86bc0161 
1/* MN10300 MMU context allocation and management
2 *
3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public Licence
8 * as published by the Free Software Foundation; either version
9 * 2 of the Licence, or (at your option) any later version.
10 */
11#include <linux/sched.h>
12#include <linux/mm.h>
13#include <asm/mmu_context.h>
14#include <asm/tlbflush.h>
15
16/*
17 * list of the MMU contexts last allocated on each CPU
18 */
19unsigned long mmu_context_cache[NR_CPUS] = {
20	[0 ... NR_CPUS - 1] = MMU_CONTEXT_FIRST_VERSION * 2 - 1,
21};
22
23/*
24 * flush the specified TLB entry
25 */
26void local_flush_tlb_page(struct mm_struct *mm, unsigned long addr)
27{
28	unsigned long pteu, cnx, flags;
29
30	addr &= PAGE_MASK;
31
32	/* make sure the context doesn't migrate and defend against
33	 * interference from vmalloc'd regions */
34	local_irq_save(flags);
35
36	cnx = mm_context(mm);
37
38	if (cnx != MMU_NO_CONTEXT) {
39		pteu = addr | (cnx & 0x000000ffUL);
40		IPTEU = pteu;
41		DPTEU = pteu;
42		if (IPTEL & xPTEL_V)
43			IPTEL = 0;
44		if (DPTEL & xPTEL_V)
45			DPTEL = 0;
46	}
47
48	local_irq_restore(flags);
49}
50
51/*
52 * preemptively set a TLB entry
53 */
54void update_mmu_cache(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
55{
56	unsigned long pteu, ptel, cnx, flags;
57	pte_t pte = *ptep;
58
59	addr &= PAGE_MASK;
60	ptel = pte_val(pte) & ~(xPTEL_UNUSED1 | xPTEL_UNUSED2);
61
62	/* make sure the context doesn't migrate and defend against
63	 * interference from vmalloc'd regions */
64	local_irq_save(flags);
65
66	cnx = mm_context(vma->vm_mm);
67
68	if (cnx != MMU_NO_CONTEXT) {
69		pteu = addr | (cnx & 0x000000ffUL);
70		if (!(pte_val(pte) & _PAGE_NX)) {
71			IPTEU = pteu;
72			if (IPTEL & xPTEL_V)
73				IPTEL = ptel;
74		}
75		DPTEU = pteu;
76		if (DPTEL & xPTEL_V)
77			DPTEL = ptel;
78	}
79
80	local_irq_restore(flags);
81}
82