summaryrefslogtreecommitdiffstats
path: root/arch/sh/mm/tlb-sh4.c
blob: 4c62347433189d874fe0ed952e20d408c9fe4652 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
/*
 * arch/sh/mm/tlb-sh4.c
 *
 * SH-4 specific TLB operations
 *
 * Copyright (C) 1999  Niibe Yutaka
 * Copyright (C) 2002 - 2007 Paul Mundt
 *
 * Released under the terms of the GNU GPL v2.0.
 */
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/io.h>
#include <asm/system.h>
#include <asm/mmu_context.h>
#include <asm/cacheflush.h>

void __update_tlb(struct vm_area_struct *vma, unsigned long address, pte_t pte)
{
	unsigned long flags, pteval, vpn;

	/*
	 * Handle debugger faulting in for debugee.
	 */
	if (vma && current->active_mm != vma->vm_mm)
		return;

	local_irq_save(flags);

	/* Set PTEH register */
	vpn = (address & MMU_VPN_MASK) | get_asid();
	ctrl_outl(vpn, MMU_PTEH);

	pteval = pte.pte_low;

	/* Set PTEA register */
#ifdef CONFIG_X2TLB
	/*
	 * For the extended mode TLB this is trivial, only the ESZ and
	 * EPR bits need to be written out to PTEA, with the remainder of
	 * the protection bits (with the exception of the compat-mode SZ
	 * and PR bits, which are cleared) being written out in PTEL.
	 */
	ctrl_outl(pte.pte_high, MMU_PTEA);
#else
	if (cpu_data->flags & CPU_HAS_PTEA) {
		/* The last 3 bits and the first one of pteval contains
		 * the PTEA timing control and space attribute bits
		 */
		ctrl_outl(copy_ptea_attributes(pteval), MMU_PTEA);
	}
#endif

	/* Set PTEL register */
	pteval &= _PAGE_FLAGS_HARDWARE_MASK; /* drop software flags */
#ifdef CONFIG_CACHE_WRITETHROUGH
	pteval |= _PAGE_WT;
#endif
	/* conveniently, we want all the software flags to be 0 anyway */
	ctrl_outl(pteval, MMU_PTEL);

	/* Load the TLB */
	asm volatile("ldtlb": /* no output */ : /* no input */ : "memory");
	local_irq_restore(flags);
}

void __uses_jump_to_uncached local_flush_tlb_one(unsigned long asid,
						 unsigned long page)
{
	unsigned long addr, data;

	/*
	 * NOTE: PTEH.ASID should be set to this MM
	 *       _AND_ we need to write ASID to the array.
	 *
	 * It would be simple if we didn't need to set PTEH.ASID...
	 */
	addr = MMU_UTLB_ADDRESS_ARRAY | MMU_PAGE_ASSOC_BIT;
	data = page | asid; /* VALID bit is off */
	jump_to_uncached();
	ctrl_outl(data, addr);
	back_to_cached();
}

/*
 * Load the entry for 'addr' into the TLB and wire the entry.
 */
void tlb_wire_entry(struct vm_area_struct *vma, unsigned long addr, pte_t pte)
{
	unsigned long status, flags;
	int urb;

	local_irq_save(flags);

	/* Load the entry into the TLB */
	__update_tlb(vma, addr, pte);

	/* ... and wire it up. */
	status = ctrl_inl(MMUCR);
	urb = (status & MMUCR_URB) >> MMUCR_URB_SHIFT;
	status &= ~MMUCR_URB;

	/*
	 * Make sure we're not trying to wire the last TLB entry slot.
	 */
	BUG_ON(!--urb);

	urb = urb % MMUCR_URB_NENTRIES;

	status |= (urb << MMUCR_URB_SHIFT);
	ctrl_outl(status, MMUCR);
	ctrl_barrier();

	local_irq_restore(flags);
}

/*
 * Unwire the last wired TLB entry.
 *
 * It should also be noted that it is not possible to wire and unwire
 * TLB entries in an arbitrary order. If you wire TLB entry N, followed
 * by entry N+1, you must unwire entry N+1 first, then entry N. In this
 * respect, it works like a stack or LIFO queue.
 */
void tlb_unwire_entry(void)
{
	unsigned long status, flags;
	int urb;

	local_irq_save(flags);

	status = ctrl_inl(MMUCR);
	urb = (status & MMUCR_URB) >> MMUCR_URB_SHIFT;
	status &= ~MMUCR_URB;

	/*
	 * Make sure we're not trying to unwire a TLB entry when none
	 * have been wired.
	 */
	BUG_ON(urb++ == MMUCR_URB_NENTRIES);

	urb = urb % MMUCR_URB_NENTRIES;

	status |= (urb << MMUCR_URB_SHIFT);
	ctrl_outl(status, MMUCR);
	ctrl_barrier();

	local_irq_restore(flags);
}