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
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
|
/*
* Intel I/OAT DMA Linux driver
* Copyright(c) 2007 Intel Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
*
* The full GNU General Public License is included in this distribution in
* the file called "COPYING".
*
*/
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/smp.h>
#include <linux/interrupt.h>
#include <linux/dca.h>
/* either a kernel change is needed, or we need something like this in kernel */
#ifndef CONFIG_SMP
#include <asm/smp.h>
#undef cpu_physical_id
#define cpu_physical_id(cpu) (cpuid_ebx(1) >> 24)
#endif
#include "ioatdma.h"
#include "ioatdma_registers.h"
/*
* Bit 16 of a tag map entry is the "valid" bit, if it is set then bits 0:15
* contain the bit number of the APIC ID to map into the DCA tag. If the valid
* bit is not set, then the value must be 0 or 1 and defines the bit in the tag.
*/
#define DCA_TAG_MAP_VALID 0x80
/*
* "Legacy" DCA systems do not implement the DCA register set in the
* I/OAT device. Software needs direct support for their tag mappings.
*/
#define APICID_BIT(x) (DCA_TAG_MAP_VALID | (x))
#define IOAT_TAG_MAP_LEN 8
static u8 ioat_tag_map_BNB[IOAT_TAG_MAP_LEN] = {
1, APICID_BIT(1), APICID_BIT(2), APICID_BIT(2), };
static u8 ioat_tag_map_SCNB[IOAT_TAG_MAP_LEN] = {
1, APICID_BIT(1), APICID_BIT(2), APICID_BIT(2), };
static u8 ioat_tag_map_CNB[IOAT_TAG_MAP_LEN] = {
1, APICID_BIT(1), APICID_BIT(3), APICID_BIT(4), APICID_BIT(2), };
static u8 ioat_tag_map_UNISYS[IOAT_TAG_MAP_LEN] = { 0 };
/* pack PCI B/D/F into a u16 */
static inline u16 dcaid_from_pcidev(struct pci_dev *pci)
{
return (pci->bus->number << 8) | pci->devfn;
}
static int dca_enabled_in_bios(struct pci_dev *pdev)
{
/* CPUID level 9 returns DCA configuration */
/* Bit 0 indicates DCA enabled by the BIOS */
unsigned long cpuid_level_9;
int res;
cpuid_level_9 = cpuid_eax(9);
res = test_bit(0, &cpuid_level_9);
if (!res)
dev_err(&pdev->dev, "DCA is disabled in BIOS\n");
return res;
}
static int system_has_dca_enabled(struct pci_dev *pdev)
{
if (boot_cpu_has(X86_FEATURE_DCA))
return dca_enabled_in_bios(pdev);
dev_err(&pdev->dev, "boot cpu doesn't have X86_FEATURE_DCA\n");
return 0;
}
struct ioat_dca_slot {
struct pci_dev *pdev; /* requester device */
u16 rid; /* requester id, as used by IOAT */
};
#define IOAT_DCA_MAX_REQ 6
struct ioat_dca_priv {
void __iomem *iobase;
void *dca_base;
int max_requesters;
int requester_count;
u8 tag_map[IOAT_TAG_MAP_LEN];
struct ioat_dca_slot req_slots[0];
};
/* 5000 series chipset DCA Port Requester ID Table Entry Format
* [15:8] PCI-Express Bus Number
* [7:3] PCI-Express Device Number
* [2:0] PCI-Express Function Number
*
* 5000 series chipset DCA control register format
* [7:1] Reserved (0)
* [0] Ignore Function Number
*/
static int ioat_dca_add_requester(struct dca_provider *dca, struct device *dev)
{
struct ioat_dca_priv *ioatdca = dca_priv(dca);
struct pci_dev *pdev;
int i;
u16 id;
/* This implementation only supports PCI-Express */
if (dev->bus != &pci_bus_type)
return -ENODEV;
pdev = to_pci_dev(dev);
id = dcaid_from_pcidev(pdev);
if (ioatdca->requester_count == ioatdca->max_requesters)
return -ENODEV;
for (i = 0; i < ioatdca->max_requesters; i++) {
if (ioatdca->req_slots[i].pdev == NULL) {
/* found an empty slot */
ioatdca->requester_count++;
ioatdca->req_slots[i].pdev = pdev;
ioatdca->req_slots[i].rid = id;
writew(id, ioatdca->dca_base + (i * 4));
/* make sure the ignore function bit is off */
writeb(0, ioatdca->dca_base + (i * 4) + 2);
return i;
}
}
/* Error, ioatdma->requester_count is out of whack */
return -EFAULT;
}
static int ioat_dca_remove_requester(struct dca_provider *dca,
struct device *dev)
{
struct ioat_dca_priv *ioatdca = dca_priv(dca);
struct pci_dev *pdev;
int i;
/* This implementation only supports PCI-Express */
if (dev->bus != &pci_bus_type)
return -ENODEV;
pdev = to_pci_dev(dev);
for (i = 0; i < ioatdca->max_requesters; i++) {
if (ioatdca->req_slots[i].pdev == pdev) {
writew(0, ioatdca->dca_base + (i * 4));
ioatdca->req_slots[i].pdev = NULL;
ioatdca->req_slots[i].rid = 0;
ioatdca->requester_count--;
return i;
}
}
return -ENODEV;
}
static u8 ioat_dca_get_tag(struct dca_provider *dca, int cpu)
{
struct ioat_dca_priv *ioatdca = dca_priv(dca);
int i, apic_id, bit, value;
u8 entry, tag;
tag = 0;
apic_id = cpu_physical_id(cpu);
for (i = 0; i < IOAT_TAG_MAP_LEN; i++) {
entry = ioatdca->tag_map[i];
if (entry & DCA_TAG_MAP_VALID) {
bit = entry & ~DCA_TAG_MAP_VALID;
value = (apic_id & (1 << bit)) ? 1 : 0;
} else {
value = entry ? 1 : 0;
}
tag |= (value << i);
}
return tag;
}
static struct dca_ops ioat_dca_ops = {
.add_requester = ioat_dca_add_requester,
.remove_requester = ioat_dca_remove_requester,
.get_tag = ioat_dca_get_tag,
};
struct dca_provider *ioat_dca_init(struct pci_dev *pdev, void __iomem *iobase)
{
struct dca_provider *dca;
struct ioat_dca_priv *ioatdca;
u8 *tag_map = NULL;
int i;
int err;
if (!system_has_dca_enabled(pdev))
return NULL;
/* I/OAT v1 systems must have a known tag_map to support DCA */
switch (pdev->vendor) {
case PCI_VENDOR_ID_INTEL:
switch (pdev->device) {
case PCI_DEVICE_ID_INTEL_IOAT:
tag_map = ioat_tag_map_BNB;
break;
case PCI_DEVICE_ID_INTEL_IOAT_CNB:
tag_map = ioat_tag_map_CNB;
break;
case PCI_DEVICE_ID_INTEL_IOAT_SCNB:
tag_map = ioat_tag_map_SCNB;
break;
}
break;
case PCI_VENDOR_ID_UNISYS:
switch (pdev->device) {
case PCI_DEVICE_ID_UNISYS_DMA_DIRECTOR:
tag_map = ioat_tag_map_UNISYS;
break;
}
break;
}
if (tag_map == NULL)
return NULL;
dca = alloc_dca_provider(&ioat_dca_ops,
sizeof(*ioatdca) +
(sizeof(struct ioat_dca_slot) * IOAT_DCA_MAX_REQ));
if (!dca)
return NULL;
ioatdca = dca_priv(dca);
ioatdca->max_requesters = IOAT_DCA_MAX_REQ;
ioatdca->dca_base = iobase + 0x54;
/* copy over the APIC ID to DCA tag mapping */
for (i = 0; i < IOAT_TAG_MAP_LEN; i++)
ioatdca->tag_map[i] = tag_map[i];
err = register_dca_provider(dca, &pdev->dev);
if (err) {
free_dca_provider(dca);
return NULL;
}
return dca;
}
|
