aboutsummaryrefslogtreecommitdiffstats
path: root/arch/ia64/sn/pci/pcibr/pcibr_ate.c
blob: 1f0253bfe0a0473f1a8b83046a4ca317204d0bf4 (plain) (blame)
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
/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 2001-2006 Silicon Graphics, Inc. All rights reserved.
 */

#include <linux/types.h>
#include <asm/sn/sn_sal.h>
#include <asm/sn/pcibr_provider.h>
#include <asm/sn/pcibus_provider_defs.h>
#include <asm/sn/pcidev.h>

int pcibr_invalidate_ate;	/* by default don't invalidate ATE on free */

/*
 * mark_ate: Mark the ate as either free or inuse.
 */
static void mark_ate(struct ate_resource *ate_resource, int start, int number,
		     u64 value)
{
	u64 *ate = ate_resource->ate;
	int index;
	int length = 0;

	for (index = start; length < number; index++, length++)
		ate[index] = value;
}

/*
 * find_free_ate:  Find the first free ate index starting from the given
 *		   index for the desired consequtive count.
 */
static int find_free_ate(struct ate_resource *ate_resource, int start,
			 int count)
{
	u64 *ate = ate_resource->ate;
	int index;
	int start_free;

	for (index = start; index < ate_resource->num_ate;) {
		if (!ate[index]) {
			int i;
			int free;
			free = 0;
			start_free = index;	/* Found start free ate */
			for (i = start_free; i < ate_resource->num_ate; i++) {
				if (!ate[i]) {	/* This is free */
					if (++free == count)
						return start_free;
				} else {
					index = i + 1;
					break;
				}
			}
		} else
			index++;	/* Try next ate */
	}

	return -1;
}

/*
 * free_ate_resource:  Free the requested number of ATEs.
 */
static inline void free_ate_resource(struct ate_resource *ate_resource,
				     int start)
{
	mark_ate(ate_resource, start, ate_resource->ate[start], 0);
	if ((ate_resource->lowest_free_index > start) ||
	    (ate_resource->lowest_free_index < 0))
		ate_resource->lowest_free_index = start;
}

/*
 * alloc_ate_resource:  Allocate the requested number of ATEs.
 */
static inline int alloc_ate_resource(struct ate_resource *ate_resource,
				     int ate_needed)
{
	int start_index;

	/*
	 * Check for ate exhaustion.
	 */
	if (ate_resource->lowest_free_index < 0)
		return -1;

	/*
	 * Find the required number of free consequtive ates.
	 */
	start_index =
	    find_free_ate(ate_resource, ate_resource->lowest_free_index,
			  ate_needed);
	if (start_index >= 0)
		mark_ate(ate_resource, start_index, ate_needed, ate_needed);

	ate_resource->lowest_free_index =
	    find_free_ate(ate_resource, ate_resource->lowest_free_index, 1);

	return start_index;
}

/*
 * Allocate "count" contiguous Bridge Address Translation Entries
 * on the specified bridge to be used for PCI to XTALK mappings.
 * Indices in rm map range from 1..num_entries.  Indicies returned
 * to caller range from 0..num_entries-1.
 *
 * Return the start index on success, -1 on failure.
 */
int pcibr_ate_alloc(struct pcibus_info *pcibus_info, int count)
{
	int status;
	unsigned long flags;

	spin_lock_irqsave(&pcibus_info->pbi_lock, flags);
	status = alloc_ate_resource(&pcibus_info->pbi_int_ate_resource, count);
	spin_unlock_irqrestore(&pcibus_info->pbi_lock, flags);

	return status;
}

/*
 * Setup an Address Translation Entry as specified.  Use either the Bridge
 * internal maps or the external map RAM, as appropriate.
 */
static inline u64 *pcibr_ate_addr(struct pcibus_info *pcibus_info,
				       int ate_index)
{
	if (ate_index < pcibus_info->pbi_int_ate_size) {
		return pcireg_int_ate_addr(pcibus_info, ate_index);
	}
	panic("pcibr_ate_addr: invalid ate_index 0x%x", ate_index);
}

/*
 * Update the ate.
 */
void inline
ate_write(struct pcibus_info *pcibus_info, int ate_index, int count,
	  volatile u64 ate)
{
	while (count-- > 0) {
		if (ate_index < pcibus_info->pbi_int_ate_size) {
			pcireg_int_ate_set(pcibus_info, ate_index, ate);
		} else {
			panic("ate_write: invalid ate_index 0x%x", ate_index);
		}
		ate_index++;
		ate += IOPGSIZE;
	}

	pcireg_tflush_get(pcibus_info);	/* wait until Bridge PIO complete */
}

void pcibr_ate_free(struct pcibus_info *pcibus_info, int index)
{

	volatile u64 ate;
	int count;
	u64 flags;

	if (pcibr_invalidate_ate) {
		/* For debugging purposes, clear the valid bit in the ATE */
		ate = *pcibr_ate_addr(pcibus_info, index);
		count = pcibus_info->pbi_int_ate_resource.ate[index];
		ate_write(pcibus_info, index, count, (ate & ~PCI32_ATE_V));
	}

	spin_lock_irqsave(&pcibus_info->pbi_lock, flags);
	free_ate_resource(&pcibus_info->pbi_int_ate_resource, index);
	spin_unlock_irqrestore(&pcibus_info->pbi_lock, flags);
}