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#ifdef CONFIG_MN10300_TLB_USE_PIDR
17/*
18 * list of the MMU contexts last allocated on each CPU
19 */
20unsigned long mmu_context_cache[NR_CPUS] = {
21	[0 ... NR_CPUS - 1] =
22	MMU_CONTEXT_FIRST_VERSION * 2 - (1 - MMU_CONTEXT_TLBPID_LOCK_NR),
23};
24#endif /* CONFIG_MN10300_TLB_USE_PIDR */
25
26/*
27 * preemptively set a TLB entry
28 */
29void update_mmu_cache(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
30{
31	unsigned long pteu, ptel, cnx, flags;
32	pte_t pte = *ptep;
33
34	addr &= PAGE_MASK;
35	ptel = pte_val(pte) & ~(xPTEL_UNUSED1 | xPTEL_UNUSED2);
36
37	/* make sure the context doesn't migrate and defend against
38	 * interference from vmalloc'd regions */
39	local_irq_save(flags);
40
41	cnx = ~MMU_NO_CONTEXT;
42#ifdef CONFIG_MN10300_TLB_USE_PIDR
43	cnx = mm_context(vma->vm_mm);
44#endif
45
46	if (cnx != MMU_NO_CONTEXT) {
47		pteu = addr;
48#ifdef CONFIG_MN10300_TLB_USE_PIDR
49		pteu |= cnx & MMU_CONTEXT_TLBPID_MASK;
50#endif
51		if (!(pte_val(pte) & _PAGE_NX)) {
52			IPTEU = pteu;
53			if (IPTEL & xPTEL_V)
54				IPTEL = ptel;
55		}
56		DPTEU = pteu;
57		if (DPTEL & xPTEL_V)
58			DPTEL = ptel;
59	}
60
61	local_irq_restore(flags);
62}
63