Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | /* |
| 3 | * Data Object Exchange |
| 4 | * PCIe r6.0, sec 6.30 DOE |
| 5 | * |
| 6 | * Copyright (C) 2021 Huawei |
| 7 | * Jonathan Cameron <Jonathan.Cameron@huawei.com> |
| 8 | * |
| 9 | * Copyright (C) 2022 Intel Corporation |
| 10 | * Ira Weiny <ira.weiny@intel.com> |
| 11 | */ |
| 12 | |
| 13 | #define dev_fmt(fmt) "DOE: " fmt |
| 14 | |
| 15 | #include <linux/bitfield.h> |
| 16 | #include <linux/delay.h> |
| 17 | #include <linux/jiffies.h> |
| 18 | #include <linux/mutex.h> |
| 19 | #include <linux/pci.h> |
| 20 | #include <linux/pci-doe.h> |
| 21 | #include <linux/workqueue.h> |
| 22 | |
Lukas Wunner | ac04840 | 2023-03-11 15:40:12 +0100 | [diff] [blame] | 23 | #include "pci.h" |
| 24 | |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 25 | #define PCI_DOE_PROTOCOL_DISCOVERY 0 |
| 26 | |
| 27 | /* Timeout of 1 second from 6.30.2 Operation, PCI Spec r6.0 */ |
| 28 | #define PCI_DOE_TIMEOUT HZ |
| 29 | #define PCI_DOE_POLL_INTERVAL (PCI_DOE_TIMEOUT / 128) |
| 30 | |
| 31 | #define PCI_DOE_FLAG_CANCEL 0 |
| 32 | #define PCI_DOE_FLAG_DEAD 1 |
| 33 | |
Li Ming | a4ff8e7 | 2022-11-16 09:56:37 +0800 | [diff] [blame] | 34 | /* Max data object length is 2^18 dwords */ |
| 35 | #define PCI_DOE_MAX_LENGTH (1 << 18) |
| 36 | |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 37 | /** |
| 38 | * struct pci_doe_mb - State for a single DOE mailbox |
| 39 | * |
| 40 | * This state is used to manage a single DOE mailbox capability. All fields |
| 41 | * should be considered opaque to the consumers and the structure passed into |
Lukas Wunner | 022b66f | 2023-03-11 15:40:11 +0100 | [diff] [blame] | 42 | * the helpers below after being created by pci_doe_create_mb(). |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 43 | * |
| 44 | * @pdev: PCI device this mailbox belongs to |
| 45 | * @cap_offset: Capability offset |
| 46 | * @prots: Array of protocols supported (encoded as long values) |
| 47 | * @wq: Wait queue for work item |
| 48 | * @work_queue: Queue of pci_doe_work items |
| 49 | * @flags: Bit array of PCI_DOE_FLAG_* flags |
| 50 | */ |
| 51 | struct pci_doe_mb { |
| 52 | struct pci_dev *pdev; |
| 53 | u16 cap_offset; |
| 54 | struct xarray prots; |
| 55 | |
| 56 | wait_queue_head_t wq; |
| 57 | struct workqueue_struct *work_queue; |
| 58 | unsigned long flags; |
| 59 | }; |
| 60 | |
Lukas Wunner | 0821ff8 | 2023-03-11 15:40:09 +0100 | [diff] [blame] | 61 | struct pci_doe_protocol { |
| 62 | u16 vid; |
| 63 | u8 type; |
| 64 | }; |
| 65 | |
| 66 | /** |
| 67 | * struct pci_doe_task - represents a single query/response |
| 68 | * |
| 69 | * @prot: DOE Protocol |
| 70 | * @request_pl: The request payload |
| 71 | * @request_pl_sz: Size of the request payload (bytes) |
| 72 | * @response_pl: The response payload |
| 73 | * @response_pl_sz: Size of the response payload (bytes) |
| 74 | * @rv: Return value. Length of received response or error (bytes) |
| 75 | * @complete: Called when task is complete |
| 76 | * @private: Private data for the consumer |
| 77 | * @work: Used internally by the mailbox |
| 78 | * @doe_mb: Used internally by the mailbox |
Lukas Wunner | 0821ff8 | 2023-03-11 15:40:09 +0100 | [diff] [blame] | 79 | */ |
| 80 | struct pci_doe_task { |
| 81 | struct pci_doe_protocol prot; |
| 82 | const __le32 *request_pl; |
| 83 | size_t request_pl_sz; |
| 84 | __le32 *response_pl; |
| 85 | size_t response_pl_sz; |
| 86 | int rv; |
| 87 | void (*complete)(struct pci_doe_task *task); |
| 88 | void *private; |
| 89 | |
| 90 | /* initialized by pci_doe_submit_task() */ |
| 91 | struct work_struct work; |
| 92 | struct pci_doe_mb *doe_mb; |
| 93 | }; |
| 94 | |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 95 | static int pci_doe_wait(struct pci_doe_mb *doe_mb, unsigned long timeout) |
| 96 | { |
| 97 | if (wait_event_timeout(doe_mb->wq, |
| 98 | test_bit(PCI_DOE_FLAG_CANCEL, &doe_mb->flags), |
| 99 | timeout)) |
| 100 | return -EIO; |
| 101 | return 0; |
| 102 | } |
| 103 | |
| 104 | static void pci_doe_write_ctrl(struct pci_doe_mb *doe_mb, u32 val) |
| 105 | { |
| 106 | struct pci_dev *pdev = doe_mb->pdev; |
| 107 | int offset = doe_mb->cap_offset; |
| 108 | |
| 109 | pci_write_config_dword(pdev, offset + PCI_DOE_CTRL, val); |
| 110 | } |
| 111 | |
| 112 | static int pci_doe_abort(struct pci_doe_mb *doe_mb) |
| 113 | { |
| 114 | struct pci_dev *pdev = doe_mb->pdev; |
| 115 | int offset = doe_mb->cap_offset; |
| 116 | unsigned long timeout_jiffies; |
| 117 | |
| 118 | pci_dbg(pdev, "[%x] Issuing Abort\n", offset); |
| 119 | |
| 120 | timeout_jiffies = jiffies + PCI_DOE_TIMEOUT; |
| 121 | pci_doe_write_ctrl(doe_mb, PCI_DOE_CTRL_ABORT); |
| 122 | |
| 123 | do { |
| 124 | int rc; |
| 125 | u32 val; |
| 126 | |
| 127 | rc = pci_doe_wait(doe_mb, PCI_DOE_POLL_INTERVAL); |
| 128 | if (rc) |
| 129 | return rc; |
| 130 | pci_read_config_dword(pdev, offset + PCI_DOE_STATUS, &val); |
| 131 | |
| 132 | /* Abort success! */ |
| 133 | if (!FIELD_GET(PCI_DOE_STATUS_ERROR, val) && |
| 134 | !FIELD_GET(PCI_DOE_STATUS_BUSY, val)) |
| 135 | return 0; |
| 136 | |
| 137 | } while (!time_after(jiffies, timeout_jiffies)); |
| 138 | |
| 139 | /* Abort has timed out and the MB is dead */ |
| 140 | pci_err(pdev, "[%x] ABORT timed out\n", offset); |
| 141 | return -EIO; |
| 142 | } |
| 143 | |
| 144 | static int pci_doe_send_req(struct pci_doe_mb *doe_mb, |
| 145 | struct pci_doe_task *task) |
| 146 | { |
| 147 | struct pci_dev *pdev = doe_mb->pdev; |
| 148 | int offset = doe_mb->cap_offset; |
Lukas Wunner | cedf8d8 | 2023-03-11 15:40:15 +0100 | [diff] [blame] | 149 | size_t length, remainder; |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 150 | u32 val; |
| 151 | int i; |
| 152 | |
| 153 | /* |
| 154 | * Check the DOE busy bit is not set. If it is set, this could indicate |
| 155 | * someone other than Linux (e.g. firmware) is using the mailbox. Note |
| 156 | * it is expected that firmware and OS will negotiate access rights via |
| 157 | * an, as yet to be defined, method. |
| 158 | */ |
| 159 | pci_read_config_dword(pdev, offset + PCI_DOE_STATUS, &val); |
| 160 | if (FIELD_GET(PCI_DOE_STATUS_BUSY, val)) |
| 161 | return -EBUSY; |
| 162 | |
| 163 | if (FIELD_GET(PCI_DOE_STATUS_ERROR, val)) |
| 164 | return -EIO; |
| 165 | |
Li Ming | a4ff8e7 | 2022-11-16 09:56:37 +0800 | [diff] [blame] | 166 | /* Length is 2 DW of header + length of payload in DW */ |
Lukas Wunner | cedf8d8 | 2023-03-11 15:40:15 +0100 | [diff] [blame] | 167 | length = 2 + DIV_ROUND_UP(task->request_pl_sz, sizeof(__le32)); |
Li Ming | a4ff8e7 | 2022-11-16 09:56:37 +0800 | [diff] [blame] | 168 | if (length > PCI_DOE_MAX_LENGTH) |
| 169 | return -EIO; |
| 170 | if (length == PCI_DOE_MAX_LENGTH) |
| 171 | length = 0; |
| 172 | |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 173 | /* Write DOE Header */ |
| 174 | val = FIELD_PREP(PCI_DOE_DATA_OBJECT_HEADER_1_VID, task->prot.vid) | |
| 175 | FIELD_PREP(PCI_DOE_DATA_OBJECT_HEADER_1_TYPE, task->prot.type); |
| 176 | pci_write_config_dword(pdev, offset + PCI_DOE_WRITE, val); |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 177 | pci_write_config_dword(pdev, offset + PCI_DOE_WRITE, |
| 178 | FIELD_PREP(PCI_DOE_DATA_OBJECT_HEADER_2_LENGTH, |
Li Ming | a4ff8e7 | 2022-11-16 09:56:37 +0800 | [diff] [blame] | 179 | length)); |
Lukas Wunner | cedf8d8 | 2023-03-11 15:40:15 +0100 | [diff] [blame] | 180 | |
| 181 | /* Write payload */ |
Lukas Wunner | fbaa382 | 2023-03-11 15:40:01 +0100 | [diff] [blame] | 182 | for (i = 0; i < task->request_pl_sz / sizeof(__le32); i++) |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 183 | pci_write_config_dword(pdev, offset + PCI_DOE_WRITE, |
Lukas Wunner | fbaa382 | 2023-03-11 15:40:01 +0100 | [diff] [blame] | 184 | le32_to_cpu(task->request_pl[i])); |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 185 | |
Lukas Wunner | cedf8d8 | 2023-03-11 15:40:15 +0100 | [diff] [blame] | 186 | /* Write last payload dword */ |
| 187 | remainder = task->request_pl_sz % sizeof(__le32); |
| 188 | if (remainder) { |
| 189 | val = 0; |
| 190 | memcpy(&val, &task->request_pl[i], remainder); |
| 191 | le32_to_cpus(&val); |
| 192 | pci_write_config_dword(pdev, offset + PCI_DOE_WRITE, val); |
| 193 | } |
| 194 | |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 195 | pci_doe_write_ctrl(doe_mb, PCI_DOE_CTRL_GO); |
| 196 | |
| 197 | return 0; |
| 198 | } |
| 199 | |
| 200 | static bool pci_doe_data_obj_ready(struct pci_doe_mb *doe_mb) |
| 201 | { |
| 202 | struct pci_dev *pdev = doe_mb->pdev; |
| 203 | int offset = doe_mb->cap_offset; |
| 204 | u32 val; |
| 205 | |
| 206 | pci_read_config_dword(pdev, offset + PCI_DOE_STATUS, &val); |
| 207 | if (FIELD_GET(PCI_DOE_STATUS_DATA_OBJECT_READY, val)) |
| 208 | return true; |
| 209 | return false; |
| 210 | } |
| 211 | |
| 212 | static int pci_doe_recv_resp(struct pci_doe_mb *doe_mb, struct pci_doe_task *task) |
| 213 | { |
Lukas Wunner | cedf8d8 | 2023-03-11 15:40:15 +0100 | [diff] [blame] | 214 | size_t length, payload_length, remainder, received; |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 215 | struct pci_dev *pdev = doe_mb->pdev; |
| 216 | int offset = doe_mb->cap_offset; |
Lukas Wunner | cedf8d8 | 2023-03-11 15:40:15 +0100 | [diff] [blame] | 217 | int i = 0; |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 218 | u32 val; |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 219 | |
| 220 | /* Read the first dword to get the protocol */ |
| 221 | pci_read_config_dword(pdev, offset + PCI_DOE_READ, &val); |
| 222 | if ((FIELD_GET(PCI_DOE_DATA_OBJECT_HEADER_1_VID, val) != task->prot.vid) || |
| 223 | (FIELD_GET(PCI_DOE_DATA_OBJECT_HEADER_1_TYPE, val) != task->prot.type)) { |
| 224 | dev_err_ratelimited(&pdev->dev, "[%x] expected [VID, Protocol] = [%04x, %02x], got [%04x, %02x]\n", |
| 225 | doe_mb->cap_offset, task->prot.vid, task->prot.type, |
| 226 | FIELD_GET(PCI_DOE_DATA_OBJECT_HEADER_1_VID, val), |
| 227 | FIELD_GET(PCI_DOE_DATA_OBJECT_HEADER_1_TYPE, val)); |
| 228 | return -EIO; |
| 229 | } |
| 230 | |
| 231 | pci_write_config_dword(pdev, offset + PCI_DOE_READ, 0); |
| 232 | /* Read the second dword to get the length */ |
| 233 | pci_read_config_dword(pdev, offset + PCI_DOE_READ, &val); |
| 234 | pci_write_config_dword(pdev, offset + PCI_DOE_READ, 0); |
| 235 | |
| 236 | length = FIELD_GET(PCI_DOE_DATA_OBJECT_HEADER_2_LENGTH, val); |
Li Ming | a4ff8e7 | 2022-11-16 09:56:37 +0800 | [diff] [blame] | 237 | /* A value of 0x0 indicates max data object length */ |
| 238 | if (!length) |
| 239 | length = PCI_DOE_MAX_LENGTH; |
| 240 | if (length < 2) |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 241 | return -EIO; |
| 242 | |
| 243 | /* First 2 dwords have already been read */ |
| 244 | length -= 2; |
Lukas Wunner | cedf8d8 | 2023-03-11 15:40:15 +0100 | [diff] [blame] | 245 | received = task->response_pl_sz; |
| 246 | payload_length = DIV_ROUND_UP(task->response_pl_sz, sizeof(__le32)); |
| 247 | remainder = task->response_pl_sz % sizeof(__le32); |
| 248 | |
| 249 | /* remainder signifies number of data bytes in last payload dword */ |
| 250 | if (!remainder) |
| 251 | remainder = sizeof(__le32); |
| 252 | |
| 253 | if (length < payload_length) { |
| 254 | received = length * sizeof(__le32); |
| 255 | payload_length = length; |
| 256 | remainder = sizeof(__le32); |
| 257 | } |
| 258 | |
| 259 | if (payload_length) { |
| 260 | /* Read all payload dwords except the last */ |
| 261 | for (; i < payload_length - 1; i++) { |
| 262 | pci_read_config_dword(pdev, offset + PCI_DOE_READ, |
| 263 | &val); |
| 264 | task->response_pl[i] = cpu_to_le32(val); |
| 265 | pci_write_config_dword(pdev, offset + PCI_DOE_READ, 0); |
| 266 | } |
| 267 | |
| 268 | /* Read last payload dword */ |
Lukas Wunner | fbaa382 | 2023-03-11 15:40:01 +0100 | [diff] [blame] | 269 | pci_read_config_dword(pdev, offset + PCI_DOE_READ, &val); |
Lukas Wunner | cedf8d8 | 2023-03-11 15:40:15 +0100 | [diff] [blame] | 270 | cpu_to_le32s(&val); |
| 271 | memcpy(&task->response_pl[i], &val, remainder); |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 272 | /* Prior to the last ack, ensure Data Object Ready */ |
Lukas Wunner | cedf8d8 | 2023-03-11 15:40:15 +0100 | [diff] [blame] | 273 | if (!pci_doe_data_obj_ready(doe_mb)) |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 274 | return -EIO; |
| 275 | pci_write_config_dword(pdev, offset + PCI_DOE_READ, 0); |
Lukas Wunner | cedf8d8 | 2023-03-11 15:40:15 +0100 | [diff] [blame] | 276 | i++; |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 277 | } |
| 278 | |
| 279 | /* Flush excess length */ |
| 280 | for (; i < length; i++) { |
| 281 | pci_read_config_dword(pdev, offset + PCI_DOE_READ, &val); |
| 282 | pci_write_config_dword(pdev, offset + PCI_DOE_READ, 0); |
| 283 | } |
| 284 | |
| 285 | /* Final error check to pick up on any since Data Object Ready */ |
| 286 | pci_read_config_dword(pdev, offset + PCI_DOE_STATUS, &val); |
| 287 | if (FIELD_GET(PCI_DOE_STATUS_ERROR, val)) |
| 288 | return -EIO; |
| 289 | |
Lukas Wunner | cedf8d8 | 2023-03-11 15:40:15 +0100 | [diff] [blame] | 290 | return received; |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 291 | } |
| 292 | |
| 293 | static void signal_task_complete(struct pci_doe_task *task, int rv) |
| 294 | { |
| 295 | task->rv = rv; |
| 296 | task->complete(task); |
Lukas Wunner | abf04be | 2023-03-11 15:40:06 +0100 | [diff] [blame] | 297 | destroy_work_on_stack(&task->work); |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 298 | } |
| 299 | |
| 300 | static void signal_task_abort(struct pci_doe_task *task, int rv) |
| 301 | { |
| 302 | struct pci_doe_mb *doe_mb = task->doe_mb; |
| 303 | struct pci_dev *pdev = doe_mb->pdev; |
| 304 | |
| 305 | if (pci_doe_abort(doe_mb)) { |
| 306 | /* |
| 307 | * If the device can't process an abort; set the mailbox dead |
| 308 | * - no more submissions |
| 309 | */ |
| 310 | pci_err(pdev, "[%x] Abort failed marking mailbox dead\n", |
| 311 | doe_mb->cap_offset); |
| 312 | set_bit(PCI_DOE_FLAG_DEAD, &doe_mb->flags); |
| 313 | } |
| 314 | signal_task_complete(task, rv); |
| 315 | } |
| 316 | |
| 317 | static void doe_statemachine_work(struct work_struct *work) |
| 318 | { |
| 319 | struct pci_doe_task *task = container_of(work, struct pci_doe_task, |
| 320 | work); |
| 321 | struct pci_doe_mb *doe_mb = task->doe_mb; |
| 322 | struct pci_dev *pdev = doe_mb->pdev; |
| 323 | int offset = doe_mb->cap_offset; |
| 324 | unsigned long timeout_jiffies; |
| 325 | u32 val; |
| 326 | int rc; |
| 327 | |
| 328 | if (test_bit(PCI_DOE_FLAG_DEAD, &doe_mb->flags)) { |
| 329 | signal_task_complete(task, -EIO); |
| 330 | return; |
| 331 | } |
| 332 | |
| 333 | /* Send request */ |
| 334 | rc = pci_doe_send_req(doe_mb, task); |
| 335 | if (rc) { |
| 336 | /* |
| 337 | * The specification does not provide any guidance on how to |
| 338 | * resolve conflicting requests from other entities. |
| 339 | * Furthermore, it is likely that busy will not be detected |
| 340 | * most of the time. Flag any detection of status busy with an |
| 341 | * error. |
| 342 | */ |
| 343 | if (rc == -EBUSY) |
| 344 | dev_err_ratelimited(&pdev->dev, "[%x] busy detected; another entity is sending conflicting requests\n", |
| 345 | offset); |
| 346 | signal_task_abort(task, rc); |
| 347 | return; |
| 348 | } |
| 349 | |
| 350 | timeout_jiffies = jiffies + PCI_DOE_TIMEOUT; |
| 351 | /* Poll for response */ |
| 352 | retry_resp: |
| 353 | pci_read_config_dword(pdev, offset + PCI_DOE_STATUS, &val); |
| 354 | if (FIELD_GET(PCI_DOE_STATUS_ERROR, val)) { |
| 355 | signal_task_abort(task, -EIO); |
| 356 | return; |
| 357 | } |
| 358 | |
| 359 | if (!FIELD_GET(PCI_DOE_STATUS_DATA_OBJECT_READY, val)) { |
| 360 | if (time_after(jiffies, timeout_jiffies)) { |
| 361 | signal_task_abort(task, -EIO); |
| 362 | return; |
| 363 | } |
| 364 | rc = pci_doe_wait(doe_mb, PCI_DOE_POLL_INTERVAL); |
| 365 | if (rc) { |
| 366 | signal_task_abort(task, rc); |
| 367 | return; |
| 368 | } |
| 369 | goto retry_resp; |
| 370 | } |
| 371 | |
| 372 | rc = pci_doe_recv_resp(doe_mb, task); |
| 373 | if (rc < 0) { |
| 374 | signal_task_abort(task, rc); |
| 375 | return; |
| 376 | } |
| 377 | |
| 378 | signal_task_complete(task, rc); |
| 379 | } |
| 380 | |
| 381 | static void pci_doe_task_complete(struct pci_doe_task *task) |
| 382 | { |
| 383 | complete(task->private); |
| 384 | } |
| 385 | |
| 386 | static int pci_doe_discovery(struct pci_doe_mb *doe_mb, u8 *index, u16 *vid, |
| 387 | u8 *protocol) |
| 388 | { |
| 389 | u32 request_pl = FIELD_PREP(PCI_DOE_DATA_OBJECT_DISC_REQ_3_INDEX, |
| 390 | *index); |
Lukas Wunner | fbaa382 | 2023-03-11 15:40:01 +0100 | [diff] [blame] | 391 | __le32 request_pl_le = cpu_to_le32(request_pl); |
| 392 | __le32 response_pl_le; |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 393 | u32 response_pl; |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 394 | int rc; |
| 395 | |
Lukas Wunner | 62e8b17 | 2023-03-11 15:40:07 +0100 | [diff] [blame] | 396 | rc = pci_doe(doe_mb, PCI_VENDOR_ID_PCI_SIG, PCI_DOE_PROTOCOL_DISCOVERY, |
| 397 | &request_pl_le, sizeof(request_pl_le), |
| 398 | &response_pl_le, sizeof(response_pl_le)); |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 399 | if (rc < 0) |
| 400 | return rc; |
| 401 | |
Lukas Wunner | 62e8b17 | 2023-03-11 15:40:07 +0100 | [diff] [blame] | 402 | if (rc != sizeof(response_pl_le)) |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 403 | return -EIO; |
| 404 | |
Lukas Wunner | fbaa382 | 2023-03-11 15:40:01 +0100 | [diff] [blame] | 405 | response_pl = le32_to_cpu(response_pl_le); |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 406 | *vid = FIELD_GET(PCI_DOE_DATA_OBJECT_DISC_RSP_3_VID, response_pl); |
| 407 | *protocol = FIELD_GET(PCI_DOE_DATA_OBJECT_DISC_RSP_3_PROTOCOL, |
| 408 | response_pl); |
| 409 | *index = FIELD_GET(PCI_DOE_DATA_OBJECT_DISC_RSP_3_NEXT_INDEX, |
| 410 | response_pl); |
| 411 | |
| 412 | return 0; |
| 413 | } |
| 414 | |
| 415 | static void *pci_doe_xa_prot_entry(u16 vid, u8 prot) |
| 416 | { |
| 417 | return xa_mk_value((vid << 8) | prot); |
| 418 | } |
| 419 | |
| 420 | static int pci_doe_cache_protocols(struct pci_doe_mb *doe_mb) |
| 421 | { |
| 422 | u8 index = 0; |
| 423 | u8 xa_idx = 0; |
| 424 | |
| 425 | do { |
| 426 | int rc; |
| 427 | u16 vid; |
| 428 | u8 prot; |
| 429 | |
| 430 | rc = pci_doe_discovery(doe_mb, &index, &vid, &prot); |
| 431 | if (rc) |
| 432 | return rc; |
| 433 | |
| 434 | pci_dbg(doe_mb->pdev, |
| 435 | "[%x] Found protocol %d vid: %x prot: %x\n", |
| 436 | doe_mb->cap_offset, xa_idx, vid, prot); |
| 437 | |
| 438 | rc = xa_insert(&doe_mb->prots, xa_idx++, |
| 439 | pci_doe_xa_prot_entry(vid, prot), GFP_KERNEL); |
| 440 | if (rc) |
| 441 | return rc; |
| 442 | } while (index); |
| 443 | |
| 444 | return 0; |
| 445 | } |
| 446 | |
Lukas Wunner | 022b66f | 2023-03-11 15:40:11 +0100 | [diff] [blame] | 447 | static void pci_doe_cancel_tasks(struct pci_doe_mb *doe_mb) |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 448 | { |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 449 | /* Stop all pending work items from starting */ |
| 450 | set_bit(PCI_DOE_FLAG_DEAD, &doe_mb->flags); |
| 451 | |
| 452 | /* Cancel an in progress work item, if necessary */ |
| 453 | set_bit(PCI_DOE_FLAG_CANCEL, &doe_mb->flags); |
| 454 | wake_up(&doe_mb->wq); |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 455 | } |
| 456 | |
| 457 | /** |
Lukas Wunner | 022b66f | 2023-03-11 15:40:11 +0100 | [diff] [blame] | 458 | * pci_doe_create_mb() - Create a DOE mailbox object |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 459 | * |
| 460 | * @pdev: PCI device to create the DOE mailbox for |
| 461 | * @cap_offset: Offset of the DOE mailbox |
| 462 | * |
| 463 | * Create a single mailbox object to manage the mailbox protocol at the |
| 464 | * cap_offset specified. |
| 465 | * |
| 466 | * RETURNS: created mailbox object on success |
| 467 | * ERR_PTR(-errno) on failure |
| 468 | */ |
Lukas Wunner | 022b66f | 2023-03-11 15:40:11 +0100 | [diff] [blame] | 469 | static struct pci_doe_mb *pci_doe_create_mb(struct pci_dev *pdev, |
| 470 | u16 cap_offset) |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 471 | { |
| 472 | struct pci_doe_mb *doe_mb; |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 473 | int rc; |
| 474 | |
Lukas Wunner | 022b66f | 2023-03-11 15:40:11 +0100 | [diff] [blame] | 475 | doe_mb = kzalloc(sizeof(*doe_mb), GFP_KERNEL); |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 476 | if (!doe_mb) |
| 477 | return ERR_PTR(-ENOMEM); |
| 478 | |
| 479 | doe_mb->pdev = pdev; |
| 480 | doe_mb->cap_offset = cap_offset; |
| 481 | init_waitqueue_head(&doe_mb->wq); |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 482 | xa_init(&doe_mb->prots); |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 483 | |
| 484 | doe_mb->work_queue = alloc_ordered_workqueue("%s %s DOE [%x]", 0, |
Lukas Wunner | 74e491e | 2023-03-11 15:40:14 +0100 | [diff] [blame] | 485 | dev_bus_name(&pdev->dev), |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 486 | pci_name(pdev), |
| 487 | doe_mb->cap_offset); |
| 488 | if (!doe_mb->work_queue) { |
| 489 | pci_err(pdev, "[%x] failed to allocate work queue\n", |
| 490 | doe_mb->cap_offset); |
Lukas Wunner | 022b66f | 2023-03-11 15:40:11 +0100 | [diff] [blame] | 491 | rc = -ENOMEM; |
| 492 | goto err_free; |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 493 | } |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 494 | |
| 495 | /* Reset the mailbox by issuing an abort */ |
| 496 | rc = pci_doe_abort(doe_mb); |
| 497 | if (rc) { |
| 498 | pci_err(pdev, "[%x] failed to reset mailbox with abort command : %d\n", |
| 499 | doe_mb->cap_offset, rc); |
Lukas Wunner | 022b66f | 2023-03-11 15:40:11 +0100 | [diff] [blame] | 500 | goto err_destroy_wq; |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 501 | } |
| 502 | |
| 503 | /* |
| 504 | * The state machine and the mailbox should be in sync now; |
Lukas Wunner | 022b66f | 2023-03-11 15:40:11 +0100 | [diff] [blame] | 505 | * Use the mailbox to query protocols. |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 506 | */ |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 507 | rc = pci_doe_cache_protocols(doe_mb); |
| 508 | if (rc) { |
| 509 | pci_err(pdev, "[%x] failed to cache protocols : %d\n", |
| 510 | doe_mb->cap_offset, rc); |
Lukas Wunner | 022b66f | 2023-03-11 15:40:11 +0100 | [diff] [blame] | 511 | goto err_cancel; |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 512 | } |
| 513 | |
| 514 | return doe_mb; |
Lukas Wunner | 022b66f | 2023-03-11 15:40:11 +0100 | [diff] [blame] | 515 | |
| 516 | err_cancel: |
| 517 | pci_doe_cancel_tasks(doe_mb); |
| 518 | xa_destroy(&doe_mb->prots); |
| 519 | err_destroy_wq: |
| 520 | destroy_workqueue(doe_mb->work_queue); |
| 521 | err_free: |
| 522 | kfree(doe_mb); |
| 523 | return ERR_PTR(rc); |
| 524 | } |
| 525 | |
| 526 | /** |
| 527 | * pci_doe_destroy_mb() - Destroy a DOE mailbox object |
| 528 | * |
Lukas Wunner | 74e491e | 2023-03-11 15:40:14 +0100 | [diff] [blame] | 529 | * @doe_mb: DOE mailbox |
Lukas Wunner | 022b66f | 2023-03-11 15:40:11 +0100 | [diff] [blame] | 530 | * |
| 531 | * Destroy all internal data structures created for the DOE mailbox. |
| 532 | */ |
Lukas Wunner | 74e491e | 2023-03-11 15:40:14 +0100 | [diff] [blame] | 533 | static void pci_doe_destroy_mb(struct pci_doe_mb *doe_mb) |
Lukas Wunner | 022b66f | 2023-03-11 15:40:11 +0100 | [diff] [blame] | 534 | { |
Lukas Wunner | 022b66f | 2023-03-11 15:40:11 +0100 | [diff] [blame] | 535 | pci_doe_cancel_tasks(doe_mb); |
| 536 | xa_destroy(&doe_mb->prots); |
| 537 | destroy_workqueue(doe_mb->work_queue); |
| 538 | kfree(doe_mb); |
| 539 | } |
| 540 | |
| 541 | /** |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 542 | * pci_doe_supports_prot() - Return if the DOE instance supports the given |
| 543 | * protocol |
| 544 | * @doe_mb: DOE mailbox capability to query |
| 545 | * @vid: Protocol Vendor ID |
| 546 | * @type: Protocol type |
| 547 | * |
| 548 | * RETURNS: True if the DOE mailbox supports the protocol specified |
| 549 | */ |
Lukas Wunner | 74e491e | 2023-03-11 15:40:14 +0100 | [diff] [blame] | 550 | static bool pci_doe_supports_prot(struct pci_doe_mb *doe_mb, u16 vid, u8 type) |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 551 | { |
| 552 | unsigned long index; |
| 553 | void *entry; |
| 554 | |
| 555 | /* The discovery protocol must always be supported */ |
| 556 | if (vid == PCI_VENDOR_ID_PCI_SIG && type == PCI_DOE_PROTOCOL_DISCOVERY) |
| 557 | return true; |
| 558 | |
| 559 | xa_for_each(&doe_mb->prots, index, entry) |
| 560 | if (entry == pci_doe_xa_prot_entry(vid, type)) |
| 561 | return true; |
| 562 | |
| 563 | return false; |
| 564 | } |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 565 | |
| 566 | /** |
| 567 | * pci_doe_submit_task() - Submit a task to be processed by the state machine |
| 568 | * |
| 569 | * @doe_mb: DOE mailbox capability to submit to |
| 570 | * @task: task to be queued |
| 571 | * |
| 572 | * Submit a DOE task (request/response) to the DOE mailbox to be processed. |
| 573 | * Returns upon queueing the task object. If the queue is full this function |
| 574 | * will sleep until there is room in the queue. |
| 575 | * |
| 576 | * task->complete will be called when the state machine is done processing this |
| 577 | * task. |
| 578 | * |
Lukas Wunner | 92dc899 | 2023-03-11 15:40:05 +0100 | [diff] [blame] | 579 | * @task must be allocated on the stack. |
| 580 | * |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 581 | * Excess data will be discarded. |
| 582 | * |
| 583 | * RETURNS: 0 when task has been successfully queued, -ERRNO on error |
| 584 | */ |
Lukas Wunner | 0821ff8 | 2023-03-11 15:40:09 +0100 | [diff] [blame] | 585 | static int pci_doe_submit_task(struct pci_doe_mb *doe_mb, |
| 586 | struct pci_doe_task *task) |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 587 | { |
| 588 | if (!pci_doe_supports_prot(doe_mb, task->prot.vid, task->prot.type)) |
| 589 | return -EINVAL; |
| 590 | |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 591 | if (test_bit(PCI_DOE_FLAG_DEAD, &doe_mb->flags)) |
| 592 | return -EIO; |
| 593 | |
| 594 | task->doe_mb = doe_mb; |
Lukas Wunner | 92dc899 | 2023-03-11 15:40:05 +0100 | [diff] [blame] | 595 | INIT_WORK_ONSTACK(&task->work, doe_statemachine_work); |
Jonathan Cameron | 9d24322 | 2022-07-19 13:52:46 -0700 | [diff] [blame] | 596 | queue_work(doe_mb->work_queue, &task->work); |
| 597 | return 0; |
| 598 | } |
Lukas Wunner | 62e8b17 | 2023-03-11 15:40:07 +0100 | [diff] [blame] | 599 | |
| 600 | /** |
| 601 | * pci_doe() - Perform Data Object Exchange |
| 602 | * |
| 603 | * @doe_mb: DOE Mailbox |
| 604 | * @vendor: Vendor ID |
| 605 | * @type: Data Object Type |
| 606 | * @request: Request payload |
| 607 | * @request_sz: Size of request payload (bytes) |
| 608 | * @response: Response payload |
| 609 | * @response_sz: Size of response payload (bytes) |
| 610 | * |
| 611 | * Submit @request to @doe_mb and store the @response. |
| 612 | * The DOE exchange is performed synchronously and may therefore sleep. |
| 613 | * |
| 614 | * Payloads are treated as opaque byte streams which are transmitted verbatim, |
| 615 | * without byte-swapping. If payloads contain little-endian register values, |
| 616 | * the caller is responsible for conversion with cpu_to_le32() / le32_to_cpu(). |
| 617 | * |
Lukas Wunner | cedf8d8 | 2023-03-11 15:40:15 +0100 | [diff] [blame] | 618 | * For convenience, arbitrary payload sizes are allowed even though PCIe r6.0 |
| 619 | * sec 6.30.1 specifies the Data Object Header 2 "Length" in dwords. The last |
| 620 | * (partial) dword is copied with byte granularity and padded with zeroes if |
| 621 | * necessary. Callers are thus relieved of using dword-sized bounce buffers. |
| 622 | * |
Lukas Wunner | 62e8b17 | 2023-03-11 15:40:07 +0100 | [diff] [blame] | 623 | * RETURNS: Length of received response or negative errno. |
| 624 | * Received data in excess of @response_sz is discarded. |
| 625 | * The length may be smaller than @response_sz and the caller |
| 626 | * is responsible for checking that. |
| 627 | */ |
| 628 | int pci_doe(struct pci_doe_mb *doe_mb, u16 vendor, u8 type, |
| 629 | const void *request, size_t request_sz, |
| 630 | void *response, size_t response_sz) |
| 631 | { |
| 632 | DECLARE_COMPLETION_ONSTACK(c); |
| 633 | struct pci_doe_task task = { |
| 634 | .prot.vid = vendor, |
| 635 | .prot.type = type, |
| 636 | .request_pl = request, |
| 637 | .request_pl_sz = request_sz, |
| 638 | .response_pl = response, |
| 639 | .response_pl_sz = response_sz, |
| 640 | .complete = pci_doe_task_complete, |
| 641 | .private = &c, |
| 642 | }; |
| 643 | int rc; |
| 644 | |
| 645 | rc = pci_doe_submit_task(doe_mb, &task); |
| 646 | if (rc) |
| 647 | return rc; |
| 648 | |
| 649 | wait_for_completion(&c); |
| 650 | |
| 651 | return task.rv; |
| 652 | } |
| 653 | EXPORT_SYMBOL_GPL(pci_doe); |
Lukas Wunner | ac04840 | 2023-03-11 15:40:12 +0100 | [diff] [blame] | 654 | |
| 655 | /** |
| 656 | * pci_find_doe_mailbox() - Find Data Object Exchange mailbox |
| 657 | * |
| 658 | * @pdev: PCI device |
| 659 | * @vendor: Vendor ID |
| 660 | * @type: Data Object Type |
| 661 | * |
| 662 | * Find first DOE mailbox of a PCI device which supports the given protocol. |
| 663 | * |
| 664 | * RETURNS: Pointer to the DOE mailbox or NULL if none was found. |
| 665 | */ |
| 666 | struct pci_doe_mb *pci_find_doe_mailbox(struct pci_dev *pdev, u16 vendor, |
| 667 | u8 type) |
| 668 | { |
| 669 | struct pci_doe_mb *doe_mb; |
| 670 | unsigned long index; |
| 671 | |
| 672 | xa_for_each(&pdev->doe_mbs, index, doe_mb) |
| 673 | if (pci_doe_supports_prot(doe_mb, vendor, type)) |
| 674 | return doe_mb; |
| 675 | |
| 676 | return NULL; |
| 677 | } |
| 678 | EXPORT_SYMBOL_GPL(pci_find_doe_mailbox); |
| 679 | |
| 680 | void pci_doe_init(struct pci_dev *pdev) |
| 681 | { |
| 682 | struct pci_doe_mb *doe_mb; |
| 683 | u16 offset = 0; |
| 684 | int rc; |
| 685 | |
| 686 | xa_init(&pdev->doe_mbs); |
| 687 | |
| 688 | while ((offset = pci_find_next_ext_capability(pdev, offset, |
| 689 | PCI_EXT_CAP_ID_DOE))) { |
| 690 | doe_mb = pci_doe_create_mb(pdev, offset); |
| 691 | if (IS_ERR(doe_mb)) { |
| 692 | pci_err(pdev, "[%x] failed to create mailbox: %ld\n", |
| 693 | offset, PTR_ERR(doe_mb)); |
| 694 | continue; |
| 695 | } |
| 696 | |
| 697 | rc = xa_insert(&pdev->doe_mbs, offset, doe_mb, GFP_KERNEL); |
| 698 | if (rc) { |
| 699 | pci_err(pdev, "[%x] failed to insert mailbox: %d\n", |
| 700 | offset, rc); |
| 701 | pci_doe_destroy_mb(doe_mb); |
| 702 | } |
| 703 | } |
| 704 | } |
| 705 | |
| 706 | void pci_doe_destroy(struct pci_dev *pdev) |
| 707 | { |
| 708 | struct pci_doe_mb *doe_mb; |
| 709 | unsigned long index; |
| 710 | |
| 711 | xa_for_each(&pdev->doe_mbs, index, doe_mb) |
| 712 | pci_doe_destroy_mb(doe_mb); |
| 713 | |
| 714 | xa_destroy(&pdev->doe_mbs); |
| 715 | } |
| 716 | |
| 717 | void pci_doe_disconnected(struct pci_dev *pdev) |
| 718 | { |
| 719 | struct pci_doe_mb *doe_mb; |
| 720 | unsigned long index; |
| 721 | |
| 722 | xa_for_each(&pdev->doe_mbs, index, doe_mb) |
| 723 | pci_doe_cancel_tasks(doe_mb); |
| 724 | } |