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2ed6dc34 SN |
1 | /* |
2 | * Intel I/OAT DMA Linux driver | |
211a22ce | 3 | * Copyright(c) 2007 - 2009 Intel Corporation. |
2ed6dc34 SN |
4 | * |
5 | * This program is free software; you can redistribute it and/or modify it | |
6 | * under the terms and conditions of the GNU General Public License, | |
7 | * version 2, as published by the Free Software Foundation. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, but WITHOUT | |
10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
12 | * more details. | |
13 | * | |
2ed6dc34 SN |
14 | * The full GNU General Public License is included in this distribution in |
15 | * the file called "COPYING". | |
16 | * | |
17 | */ | |
18 | ||
19 | #include <linux/kernel.h> | |
20 | #include <linux/pci.h> | |
21 | #include <linux/smp.h> | |
22 | #include <linux/interrupt.h> | |
23 | #include <linux/dca.h> | |
24 | ||
25 | /* either a kernel change is needed, or we need something like this in kernel */ | |
26 | #ifndef CONFIG_SMP | |
27 | #include <asm/smp.h> | |
28 | #undef cpu_physical_id | |
29 | #define cpu_physical_id(cpu) (cpuid_ebx(1) >> 24) | |
30 | #endif | |
31 | ||
584ec227 DW |
32 | #include "dma.h" |
33 | #include "registers.h" | |
2ed6dc34 SN |
34 | |
35 | /* | |
7f1b358a | 36 | * Bit 7 of a tag map entry is the "valid" bit, if it is set then bits 0:6 |
2ed6dc34 SN |
37 | * contain the bit number of the APIC ID to map into the DCA tag. If the valid |
38 | * bit is not set, then the value must be 0 or 1 and defines the bit in the tag. | |
39 | */ | |
40 | #define DCA_TAG_MAP_VALID 0x80 | |
41 | ||
7f1b358a MS |
42 | #define DCA3_TAG_MAP_BIT_TO_INV 0x80 |
43 | #define DCA3_TAG_MAP_BIT_TO_SEL 0x40 | |
44 | #define DCA3_TAG_MAP_LITERAL_VAL 0x1 | |
45 | ||
46 | #define DCA_TAG_MAP_MASK 0xDF | |
47 | ||
49bc4636 MS |
48 | /* expected tag map bytes for I/OAT ver.2 */ |
49 | #define DCA2_TAG_MAP_BYTE0 0x80 | |
50 | #define DCA2_TAG_MAP_BYTE1 0x0 | |
51 | #define DCA2_TAG_MAP_BYTE2 0x81 | |
52 | #define DCA2_TAG_MAP_BYTE3 0x82 | |
53 | #define DCA2_TAG_MAP_BYTE4 0x82 | |
54 | ||
55 | /* verify if tag map matches expected values */ | |
56 | static inline int dca2_tag_map_valid(u8 *tag_map) | |
57 | { | |
58 | return ((tag_map[0] == DCA2_TAG_MAP_BYTE0) && | |
59 | (tag_map[1] == DCA2_TAG_MAP_BYTE1) && | |
60 | (tag_map[2] == DCA2_TAG_MAP_BYTE2) && | |
61 | (tag_map[3] == DCA2_TAG_MAP_BYTE3) && | |
62 | (tag_map[4] == DCA2_TAG_MAP_BYTE4)); | |
63 | } | |
64 | ||
2ed6dc34 SN |
65 | /* |
66 | * "Legacy" DCA systems do not implement the DCA register set in the | |
67 | * I/OAT device. Software needs direct support for their tag mappings. | |
68 | */ | |
69 | ||
70 | #define APICID_BIT(x) (DCA_TAG_MAP_VALID | (x)) | |
71 | #define IOAT_TAG_MAP_LEN 8 | |
72 | ||
2ed6dc34 SN |
73 | /* pack PCI B/D/F into a u16 */ |
74 | static inline u16 dcaid_from_pcidev(struct pci_dev *pci) | |
75 | { | |
76 | return (pci->bus->number << 8) | pci->devfn; | |
77 | } | |
78 | ||
5149fd01 | 79 | static int dca_enabled_in_bios(struct pci_dev *pdev) |
2ed6dc34 SN |
80 | { |
81 | /* CPUID level 9 returns DCA configuration */ | |
82 | /* Bit 0 indicates DCA enabled by the BIOS */ | |
83 | unsigned long cpuid_level_9; | |
84 | int res; | |
85 | ||
86 | cpuid_level_9 = cpuid_eax(9); | |
87 | res = test_bit(0, &cpuid_level_9); | |
88 | if (!res) | |
e22dde99 | 89 | dev_dbg(&pdev->dev, "DCA is disabled in BIOS\n"); |
2ed6dc34 SN |
90 | |
91 | return res; | |
92 | } | |
93 | ||
228c4f5c | 94 | int system_has_dca_enabled(struct pci_dev *pdev) |
2ed6dc34 SN |
95 | { |
96 | if (boot_cpu_has(X86_FEATURE_DCA)) | |
5149fd01 | 97 | return dca_enabled_in_bios(pdev); |
2ed6dc34 | 98 | |
e22dde99 | 99 | dev_dbg(&pdev->dev, "boot cpu doesn't have X86_FEATURE_DCA\n"); |
2ed6dc34 SN |
100 | return 0; |
101 | } | |
102 | ||
103 | struct ioat_dca_slot { | |
104 | struct pci_dev *pdev; /* requester device */ | |
105 | u16 rid; /* requester id, as used by IOAT */ | |
106 | }; | |
107 | ||
108 | #define IOAT_DCA_MAX_REQ 6 | |
7f1b358a | 109 | #define IOAT3_DCA_MAX_REQ 2 |
2ed6dc34 SN |
110 | |
111 | struct ioat_dca_priv { | |
112 | void __iomem *iobase; | |
53a0c98e | 113 | void __iomem *dca_base; |
2ed6dc34 SN |
114 | int max_requesters; |
115 | int requester_count; | |
116 | u8 tag_map[IOAT_TAG_MAP_LEN]; | |
117 | struct ioat_dca_slot req_slots[0]; | |
118 | }; | |
119 | ||
7f1b358a MS |
120 | static int ioat_dca_dev_managed(struct dca_provider *dca, |
121 | struct device *dev) | |
122 | { | |
123 | struct ioat_dca_priv *ioatdca = dca_priv(dca); | |
124 | struct pci_dev *pdev; | |
125 | int i; | |
126 | ||
127 | pdev = to_pci_dev(dev); | |
128 | for (i = 0; i < ioatdca->max_requesters; i++) { | |
129 | if (ioatdca->req_slots[i].pdev == pdev) | |
130 | return 1; | |
131 | } | |
132 | return 0; | |
133 | } | |
134 | ||
3372de58 | 135 | static int ioat_dca_add_requester(struct dca_provider *dca, struct device *dev) |
7f1b358a MS |
136 | { |
137 | struct ioat_dca_priv *ioatdca = dca_priv(dca); | |
138 | struct pci_dev *pdev; | |
139 | int i; | |
140 | u16 id; | |
141 | u16 global_req_table; | |
142 | ||
143 | /* This implementation only supports PCI-Express */ | |
1fde2548 | 144 | if (!dev_is_pci(dev)) |
7f1b358a MS |
145 | return -ENODEV; |
146 | pdev = to_pci_dev(dev); | |
147 | id = dcaid_from_pcidev(pdev); | |
148 | ||
149 | if (ioatdca->requester_count == ioatdca->max_requesters) | |
150 | return -ENODEV; | |
151 | ||
152 | for (i = 0; i < ioatdca->max_requesters; i++) { | |
153 | if (ioatdca->req_slots[i].pdev == NULL) { | |
154 | /* found an empty slot */ | |
155 | ioatdca->requester_count++; | |
156 | ioatdca->req_slots[i].pdev = pdev; | |
157 | ioatdca->req_slots[i].rid = id; | |
158 | global_req_table = | |
159 | readw(ioatdca->dca_base + IOAT3_DCA_GREQID_OFFSET); | |
160 | writel(id | IOAT_DCA_GREQID_VALID, | |
161 | ioatdca->iobase + global_req_table + (i * 4)); | |
162 | return i; | |
163 | } | |
164 | } | |
165 | /* Error, ioatdma->requester_count is out of whack */ | |
166 | return -EFAULT; | |
167 | } | |
168 | ||
3372de58 | 169 | static int ioat_dca_remove_requester(struct dca_provider *dca, |
7f1b358a MS |
170 | struct device *dev) |
171 | { | |
172 | struct ioat_dca_priv *ioatdca = dca_priv(dca); | |
173 | struct pci_dev *pdev; | |
174 | int i; | |
175 | u16 global_req_table; | |
176 | ||
177 | /* This implementation only supports PCI-Express */ | |
1fde2548 | 178 | if (!dev_is_pci(dev)) |
7f1b358a MS |
179 | return -ENODEV; |
180 | pdev = to_pci_dev(dev); | |
181 | ||
182 | for (i = 0; i < ioatdca->max_requesters; i++) { | |
183 | if (ioatdca->req_slots[i].pdev == pdev) { | |
184 | global_req_table = | |
185 | readw(ioatdca->dca_base + IOAT3_DCA_GREQID_OFFSET); | |
186 | writel(0, ioatdca->iobase + global_req_table + (i * 4)); | |
187 | ioatdca->req_slots[i].pdev = NULL; | |
188 | ioatdca->req_slots[i].rid = 0; | |
189 | ioatdca->requester_count--; | |
190 | return i; | |
191 | } | |
192 | } | |
193 | return -ENODEV; | |
194 | } | |
195 | ||
3372de58 | 196 | static u8 ioat_dca_get_tag(struct dca_provider *dca, |
7f1b358a MS |
197 | struct device *dev, |
198 | int cpu) | |
199 | { | |
200 | u8 tag; | |
201 | ||
202 | struct ioat_dca_priv *ioatdca = dca_priv(dca); | |
203 | int i, apic_id, bit, value; | |
204 | u8 entry; | |
205 | ||
206 | tag = 0; | |
207 | apic_id = cpu_physical_id(cpu); | |
208 | ||
209 | for (i = 0; i < IOAT_TAG_MAP_LEN; i++) { | |
210 | entry = ioatdca->tag_map[i]; | |
211 | if (entry & DCA3_TAG_MAP_BIT_TO_SEL) { | |
212 | bit = entry & | |
213 | ~(DCA3_TAG_MAP_BIT_TO_SEL | DCA3_TAG_MAP_BIT_TO_INV); | |
214 | value = (apic_id & (1 << bit)) ? 1 : 0; | |
215 | } else if (entry & DCA3_TAG_MAP_BIT_TO_INV) { | |
216 | bit = entry & ~DCA3_TAG_MAP_BIT_TO_INV; | |
217 | value = (apic_id & (1 << bit)) ? 0 : 1; | |
218 | } else { | |
219 | value = (entry & DCA3_TAG_MAP_LITERAL_VAL) ? 1 : 0; | |
220 | } | |
221 | tag |= (value << i); | |
222 | } | |
223 | ||
224 | return tag; | |
225 | } | |
226 | ||
2bb129eb | 227 | static const struct dca_ops ioat_dca_ops = { |
3372de58 DJ |
228 | .add_requester = ioat_dca_add_requester, |
229 | .remove_requester = ioat_dca_remove_requester, | |
230 | .get_tag = ioat_dca_get_tag, | |
7f1b358a MS |
231 | .dev_managed = ioat_dca_dev_managed, |
232 | }; | |
233 | ||
3372de58 | 234 | static int ioat_dca_count_dca_slots(void *iobase, u16 dca_offset) |
7f1b358a MS |
235 | { |
236 | int slots = 0; | |
237 | u32 req; | |
238 | u16 global_req_table; | |
239 | ||
240 | global_req_table = readw(iobase + dca_offset + IOAT3_DCA_GREQID_OFFSET); | |
241 | if (global_req_table == 0) | |
242 | return 0; | |
243 | ||
244 | do { | |
245 | req = readl(iobase + global_req_table + (slots * sizeof(u32))); | |
246 | slots++; | |
247 | } while ((req & IOAT_DCA_GREQID_LASTID) == 0); | |
248 | ||
249 | return slots; | |
250 | } | |
251 | ||
07bd34db AD |
252 | static inline int dca3_tag_map_invalid(u8 *tag_map) |
253 | { | |
254 | /* | |
255 | * If the tag map is not programmed by the BIOS the default is: | |
256 | * 0x80 0x80 0x80 0x80 0x80 0x00 0x00 0x00 | |
257 | * | |
258 | * This an invalid map and will result in only 2 possible tags | |
259 | * 0x1F and 0x00. 0x00 is an invalid DCA tag so we know that | |
260 | * this entire definition is invalid. | |
261 | */ | |
262 | return ((tag_map[0] == DCA_TAG_MAP_VALID) && | |
263 | (tag_map[1] == DCA_TAG_MAP_VALID) && | |
264 | (tag_map[2] == DCA_TAG_MAP_VALID) && | |
265 | (tag_map[3] == DCA_TAG_MAP_VALID) && | |
266 | (tag_map[4] == DCA_TAG_MAP_VALID)); | |
267 | } | |
268 | ||
3372de58 | 269 | struct dca_provider *ioat_dca_init(struct pci_dev *pdev, void __iomem *iobase) |
7f1b358a MS |
270 | { |
271 | struct dca_provider *dca; | |
272 | struct ioat_dca_priv *ioatdca; | |
273 | int slots; | |
274 | int i; | |
275 | int err; | |
276 | u16 dca_offset; | |
277 | u16 csi_fsb_control; | |
278 | u16 pcie_control; | |
279 | u8 bit; | |
280 | ||
281 | union { | |
282 | u64 full; | |
283 | struct { | |
284 | u32 low; | |
285 | u32 high; | |
286 | }; | |
287 | } tag_map; | |
288 | ||
289 | if (!system_has_dca_enabled(pdev)) | |
290 | return NULL; | |
291 | ||
292 | dca_offset = readw(iobase + IOAT_DCAOFFSET_OFFSET); | |
293 | if (dca_offset == 0) | |
294 | return NULL; | |
295 | ||
3372de58 | 296 | slots = ioat_dca_count_dca_slots(iobase, dca_offset); |
7f1b358a MS |
297 | if (slots == 0) |
298 | return NULL; | |
299 | ||
3372de58 | 300 | dca = alloc_dca_provider(&ioat_dca_ops, |
7f1b358a MS |
301 | sizeof(*ioatdca) |
302 | + (sizeof(struct ioat_dca_slot) * slots)); | |
303 | if (!dca) | |
304 | return NULL; | |
305 | ||
306 | ioatdca = dca_priv(dca); | |
307 | ioatdca->iobase = iobase; | |
308 | ioatdca->dca_base = iobase + dca_offset; | |
309 | ioatdca->max_requesters = slots; | |
310 | ||
311 | /* some bios might not know to turn these on */ | |
312 | csi_fsb_control = readw(ioatdca->dca_base + IOAT3_CSI_CONTROL_OFFSET); | |
313 | if ((csi_fsb_control & IOAT3_CSI_CONTROL_PREFETCH) == 0) { | |
314 | csi_fsb_control |= IOAT3_CSI_CONTROL_PREFETCH; | |
315 | writew(csi_fsb_control, | |
316 | ioatdca->dca_base + IOAT3_CSI_CONTROL_OFFSET); | |
317 | } | |
318 | pcie_control = readw(ioatdca->dca_base + IOAT3_PCI_CONTROL_OFFSET); | |
319 | if ((pcie_control & IOAT3_PCI_CONTROL_MEMWR) == 0) { | |
320 | pcie_control |= IOAT3_PCI_CONTROL_MEMWR; | |
321 | writew(pcie_control, | |
322 | ioatdca->dca_base + IOAT3_PCI_CONTROL_OFFSET); | |
323 | } | |
324 | ||
325 | ||
326 | /* TODO version, compatibility and configuration checks */ | |
327 | ||
328 | /* copy out the APIC to DCA tag map */ | |
329 | tag_map.low = | |
330 | readl(ioatdca->dca_base + IOAT3_APICID_TAG_MAP_OFFSET_LOW); | |
331 | tag_map.high = | |
332 | readl(ioatdca->dca_base + IOAT3_APICID_TAG_MAP_OFFSET_HIGH); | |
333 | for (i = 0; i < 8; i++) { | |
334 | bit = tag_map.full >> (8 * i); | |
335 | ioatdca->tag_map[i] = bit & DCA_TAG_MAP_MASK; | |
336 | } | |
337 | ||
07bd34db | 338 | if (dca3_tag_map_invalid(ioatdca->tag_map)) { |
036e9ef8 PB |
339 | add_taint(TAINT_FIRMWARE_WORKAROUND, LOCKDEP_STILL_OK); |
340 | pr_warn_once("%s %s: APICID_TAG_MAP set incorrectly by BIOS, disabling DCA\n", | |
341 | dev_driver_string(&pdev->dev), | |
342 | dev_name(&pdev->dev)); | |
07bd34db AD |
343 | free_dca_provider(dca); |
344 | return NULL; | |
345 | } | |
346 | ||
7f1b358a MS |
347 | err = register_dca_provider(dca, &pdev->dev); |
348 | if (err) { | |
349 | free_dca_provider(dca); | |
350 | return NULL; | |
351 | } | |
352 | ||
353 | return dca; | |
354 | } |