summaryrefslogtreecommitdiffstats
path: root/arch/ia64/mm/tlb.c
blob: 464557e4ed8241f5755782730495a4e434446c59 (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
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
/*
 * TLB support routines.
 *
 * Copyright (C) 1998-2001, 2003 Hewlett-Packard Co
 *	David Mosberger-Tang <davidm@hpl.hp.com>
 *
 * 08/02/00 A. Mallick <asit.k.mallick@intel.com>
 *		Modified RID allocation for SMP
 *          Goutham Rao <goutham.rao@intel.com>
 *              IPI based ptc implementation and A-step IPI implementation.
 */
#include <linux/config.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/mm.h>

#include <asm/delay.h>
#include <asm/mmu_context.h>
#include <asm/pgalloc.h>
#include <asm/pal.h>
#include <asm/tlbflush.h>

static struct {
	unsigned long mask;	/* mask of supported purge page-sizes */
	unsigned long max_bits;	/* log2() of largest supported purge page-size */
} purge;

struct ia64_ctx ia64_ctx = {
	.lock =		SPIN_LOCK_UNLOCKED,
	.next =		1,
	.limit =	(1 << 15) - 1,		/* start out with the safe (architected) limit */
	.max_ctx =	~0U
};

DEFINE_PER_CPU(u8, ia64_need_tlb_flush);

/*
 * Acquire the ia64_ctx.lock before calling this function!
 */
void
wrap_mmu_context (struct mm_struct *mm)
{
	unsigned long tsk_context, max_ctx = ia64_ctx.max_ctx;
	struct task_struct *tsk;
	int i;

	if (ia64_ctx.next > max_ctx)
		ia64_ctx.next = 300;	/* skip daemons */
	ia64_ctx.limit = max_ctx + 1;

	/*
	 * Scan all the task's mm->context and set proper safe range
	 */

	read_lock(&tasklist_lock);
  repeat:
	for_each_process(tsk) {
		if (!tsk->mm)
			continue;
		tsk_context = tsk->mm->context;
		if (tsk_context == ia64_ctx.next) {
			if (++ia64_ctx.next >= ia64_ctx.limit) {
				/* empty range: reset the range limit and start over */
				if (ia64_ctx.next > max_ctx)
					ia64_ctx.next = 300;
				ia64_ctx.limit = max_ctx + 1;
				goto repeat;
			}
		}
		if ((tsk_context > ia64_ctx.next) && (tsk_context < ia64_ctx.limit))
			ia64_ctx.limit = tsk_context;
	}
	read_unlock(&tasklist_lock);
	/* can't call flush_tlb_all() here because of race condition with O(1) scheduler [EF] */
	{
		int cpu = get_cpu(); /* prevent preemption/migration */
		for (i = 0; i < NR_CPUS; ++i)
			if (cpu_online(i) && (i != cpu))
				per_cpu(ia64_need_tlb_flush, i) = 1;
		put_cpu();
	}
	local_flush_tlb_all();
}

void
ia64_global_tlb_purge (unsigned long start, unsigned long end, unsigned long nbits)
{
	static DEFINE_SPINLOCK(ptcg_lock);

	/* HW requires global serialization of ptc.ga.  */
	spin_lock(&ptcg_lock);
	{
		do {
			/*
			 * Flush ALAT entries also.
			 */
			ia64_ptcga(start, (nbits<<2));
			ia64_srlz_i();
			start += (1UL << nbits);
		} while (start < end);
	}
	spin_unlock(&ptcg_lock);
}

void
local_flush_tlb_all (void)
{
	unsigned long i, j, flags, count0, count1, stride0, stride1, addr;

	addr    = local_cpu_data->ptce_base;
	count0  = local_cpu_data->ptce_count[0];
	count1  = local_cpu_data->ptce_count[1];
	stride0 = local_cpu_data->ptce_stride[0];
	stride1 = local_cpu_data->ptce_stride[1];

	local_irq_save(flags);
	for (i = 0; i < count0; ++i) {
		for (j = 0; j < count1; ++j) {
			ia64_ptce(addr);
			addr += stride1;
		}
		addr += stride0;
	}
	local_irq_restore(flags);
	ia64_srlz_i();			/* srlz.i implies srlz.d */
}

void
flush_tlb_range (struct vm_area_struct *vma, unsigned long start, unsigned long end)
{
	struct mm_struct *mm = vma->vm_mm;
	unsigned long size = end - start;
	unsigned long nbits;

	if (mm != current->active_mm) {
		/* this does happen, but perhaps it's not worth optimizing for? */
#ifdef CONFIG_SMP
		flush_tlb_all();
#else
		mm->context = 0;
#endif
		return;
	}

	nbits = ia64_fls(size + 0xfff);
	while (unlikely (((1UL << nbits) & purge.mask) == 0) && (nbits < purge.max_bits))
		++nbits;
	if (nbits > purge.max_bits)
		nbits = purge.max_bits;
	start &= ~((1UL << nbits) - 1);

# ifdef CONFIG_SMP
	platform_global_tlb_purge(start, end, nbits);
# else
	do {
		ia64_ptcl(start, (nbits<<2));
		start += (1UL << nbits);
	} while (start < end);
# endif

	ia64_srlz_i();			/* srlz.i implies srlz.d */
}
EXPORT_SYMBOL(flush_tlb_range);

void __devinit
ia64_tlb_init (void)
{
	ia64_ptce_info_t ptce_info;
	unsigned long tr_pgbits;
	long status;

	if ((status = ia64_pal_vm_page_size(&tr_pgbits, &purge.mask)) != 0) {
		printk(KERN_ERR "PAL_VM_PAGE_SIZE failed with status=%ld;"
		       "defaulting to architected purge page-sizes.\n", status);
		purge.mask = 0x115557000UL;
	}
	purge.max_bits = ia64_fls(purge.mask);

	ia64_get_ptce(&ptce_info);
	local_cpu_data->ptce_base = ptce_info.base;
	local_cpu_data->ptce_count[0] = ptce_info.count[0];
	local_cpu_data->ptce_count[1] = ptce_info.count[1];
	local_cpu_data->ptce_stride[0] = ptce_info.stride[0];
	local_cpu_data->ptce_stride[1] = ptce_info.stride[1];

	local_flush_tlb_all();		/* nuke left overs from bootstrapping... */
}
OpenPOWER on IntegriCloud