Ashwin Chaugule | 86c22f8 | 2014-11-12 19:59:38 -0500 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2014 Linaro Ltd. |
| 3 | * Author: Ashwin Chaugule <ashwin.chaugule@linaro.org> |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU General Public License as published by |
| 7 | * the Free Software Foundation; either version 2 of the License, or |
| 8 | * (at your option) any later version. |
| 9 | * |
| 10 | * This program is distributed in the hope that it will be useful, |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | * GNU General Public License for more details. |
| 14 | * |
| 15 | * PCC (Platform Communication Channel) is defined in the ACPI 5.0+ |
| 16 | * specification. It is a mailbox like mechanism to allow clients |
| 17 | * such as CPPC (Collaborative Processor Performance Control), RAS |
| 18 | * (Reliability, Availability and Serviceability) and MPST (Memory |
| 19 | * Node Power State Table) to talk to the platform (e.g. BMC) through |
| 20 | * shared memory regions as defined in the PCC table entries. The PCC |
| 21 | * specification supports a Doorbell mechanism for the PCC clients |
| 22 | * to notify the platform about new data. This Doorbell information |
Ashwin Chaugule | 33350e6 | 2015-01-27 16:03:57 -0500 | [diff] [blame] | 23 | * is also specified in each PCC table entry. |
Ashwin Chaugule | 86c22f8 | 2014-11-12 19:59:38 -0500 | [diff] [blame] | 24 | * |
Ashwin Chaugule | 33350e6 | 2015-01-27 16:03:57 -0500 | [diff] [blame] | 25 | * Typical high level flow of operation is: |
| 26 | * |
| 27 | * PCC Reads: |
| 28 | * * Client tries to acquire a channel lock. |
| 29 | * * After it is acquired it writes READ cmd in communication region cmd |
| 30 | * address. |
| 31 | * * Client issues mbox_send_message() which rings the PCC doorbell |
| 32 | * for its PCC channel. |
| 33 | * * If command completes, then client has control over channel and |
| 34 | * it can proceed with its reads. |
| 35 | * * Client releases lock. |
| 36 | * |
| 37 | * PCC Writes: |
| 38 | * * Client tries to acquire channel lock. |
| 39 | * * Client writes to its communication region after it acquires a |
| 40 | * channel lock. |
| 41 | * * Client writes WRITE cmd in communication region cmd address. |
| 42 | * * Client issues mbox_send_message() which rings the PCC doorbell |
| 43 | * for its PCC channel. |
| 44 | * * If command completes, then writes have succeded and it can release |
| 45 | * the channel lock. |
| 46 | * |
| 47 | * There is a Nominal latency defined for each channel which indicates |
| 48 | * how long to wait until a command completes. If command is not complete |
| 49 | * the client needs to retry or assume failure. |
| 50 | * |
| 51 | * For more details about PCC, please see the ACPI specification from |
Ashwin Chaugule | 86c22f8 | 2014-11-12 19:59:38 -0500 | [diff] [blame] | 52 | * http://www.uefi.org/ACPIv5.1 Section 14. |
| 53 | * |
| 54 | * This file implements PCC as a Mailbox controller and allows for PCC |
| 55 | * clients to be implemented as its Mailbox Client Channels. |
| 56 | */ |
| 57 | |
| 58 | #include <linux/acpi.h> |
| 59 | #include <linux/delay.h> |
| 60 | #include <linux/io.h> |
| 61 | #include <linux/init.h> |
hotran | aca314e | 2016-08-15 17:14:05 -0700 | [diff] [blame] | 62 | #include <linux/interrupt.h> |
Ashwin Chaugule | 86c22f8 | 2014-11-12 19:59:38 -0500 | [diff] [blame] | 63 | #include <linux/list.h> |
| 64 | #include <linux/platform_device.h> |
| 65 | #include <linux/mailbox_controller.h> |
| 66 | #include <linux/mailbox_client.h> |
Prakash, Prashanth | 8b0f578 | 2016-02-17 13:21:01 -0700 | [diff] [blame] | 67 | #include <linux/io-64-nonatomic-lo-hi.h> |
Hoan Tran | 6ca595a | 2016-11-14 11:19:02 -0800 | [diff] [blame] | 68 | #include <acpi/pcc.h> |
Ashwin Chaugule | 86c22f8 | 2014-11-12 19:59:38 -0500 | [diff] [blame] | 69 | |
| 70 | #include "mailbox.h" |
| 71 | |
| 72 | #define MAX_PCC_SUBSPACES 256 |
hotran | aca314e | 2016-08-15 17:14:05 -0700 | [diff] [blame] | 73 | #define MBOX_IRQ_NAME "pcc-mbox" |
Ashwin Chaugule | 86c22f8 | 2014-11-12 19:59:38 -0500 | [diff] [blame] | 74 | |
| 75 | static struct mbox_chan *pcc_mbox_channels; |
| 76 | |
Prakash, Prashanth | 8b0f578 | 2016-02-17 13:21:01 -0700 | [diff] [blame] | 77 | /* Array of cached virtual address for doorbell registers */ |
| 78 | static void __iomem **pcc_doorbell_vaddr; |
hotran | aca314e | 2016-08-15 17:14:05 -0700 | [diff] [blame] | 79 | /* Array of cached virtual address for doorbell ack registers */ |
| 80 | static void __iomem **pcc_doorbell_ack_vaddr; |
| 81 | /* Array of doorbell interrupts */ |
| 82 | static int *pcc_doorbell_irq; |
Prakash, Prashanth | 8b0f578 | 2016-02-17 13:21:01 -0700 | [diff] [blame] | 83 | |
Ashwin Chaugule | 86c22f8 | 2014-11-12 19:59:38 -0500 | [diff] [blame] | 84 | static struct mbox_controller pcc_mbox_ctrl = {}; |
| 85 | /** |
| 86 | * get_pcc_channel - Given a PCC subspace idx, get |
| 87 | * the respective mbox_channel. |
| 88 | * @id: PCC subspace index. |
| 89 | * |
| 90 | * Return: ERR_PTR(errno) if error, else pointer |
| 91 | * to mbox channel. |
| 92 | */ |
| 93 | static struct mbox_chan *get_pcc_channel(int id) |
| 94 | { |
Hoan Tran | ecfc159 | 2017-07-21 15:09:29 -0700 | [diff] [blame] | 95 | if (id < 0 || id >= pcc_mbox_ctrl.num_chans) |
Ashwin Chaugule | 86c22f8 | 2014-11-12 19:59:38 -0500 | [diff] [blame] | 96 | return ERR_PTR(-ENOENT); |
| 97 | |
Alexey Klimov | e9c8dc8 | 2015-12-10 17:28:37 +0000 | [diff] [blame] | 98 | return &pcc_mbox_channels[id]; |
Ashwin Chaugule | 86c22f8 | 2014-11-12 19:59:38 -0500 | [diff] [blame] | 99 | } |
| 100 | |
Prakash, Prashanth | 8b0f578 | 2016-02-17 13:21:01 -0700 | [diff] [blame] | 101 | /* |
| 102 | * PCC can be used with perf critical drivers such as CPPC |
| 103 | * So it makes sense to locally cache the virtual address and |
| 104 | * use it to read/write to PCC registers such as doorbell register |
| 105 | * |
| 106 | * The below read_register and write_registers are used to read and |
| 107 | * write from perf critical registers such as PCC doorbell register |
| 108 | */ |
| 109 | static int read_register(void __iomem *vaddr, u64 *val, unsigned int bit_width) |
| 110 | { |
| 111 | int ret_val = 0; |
| 112 | |
| 113 | switch (bit_width) { |
| 114 | case 8: |
| 115 | *val = readb(vaddr); |
| 116 | break; |
| 117 | case 16: |
| 118 | *val = readw(vaddr); |
| 119 | break; |
| 120 | case 32: |
| 121 | *val = readl(vaddr); |
| 122 | break; |
| 123 | case 64: |
| 124 | *val = readq(vaddr); |
| 125 | break; |
| 126 | default: |
| 127 | pr_debug("Error: Cannot read register of %u bit width", |
| 128 | bit_width); |
| 129 | ret_val = -EFAULT; |
| 130 | break; |
| 131 | } |
| 132 | return ret_val; |
| 133 | } |
| 134 | |
| 135 | static int write_register(void __iomem *vaddr, u64 val, unsigned int bit_width) |
| 136 | { |
| 137 | int ret_val = 0; |
| 138 | |
| 139 | switch (bit_width) { |
| 140 | case 8: |
| 141 | writeb(val, vaddr); |
| 142 | break; |
| 143 | case 16: |
| 144 | writew(val, vaddr); |
| 145 | break; |
| 146 | case 32: |
| 147 | writel(val, vaddr); |
| 148 | break; |
| 149 | case 64: |
| 150 | writeq(val, vaddr); |
| 151 | break; |
| 152 | default: |
| 153 | pr_debug("Error: Cannot write register of %u bit width", |
| 154 | bit_width); |
| 155 | ret_val = -EFAULT; |
| 156 | break; |
| 157 | } |
| 158 | return ret_val; |
| 159 | } |
| 160 | |
Ashwin Chaugule | 86c22f8 | 2014-11-12 19:59:38 -0500 | [diff] [blame] | 161 | /** |
hotran | aca314e | 2016-08-15 17:14:05 -0700 | [diff] [blame] | 162 | * pcc_map_interrupt - Map a PCC subspace GSI to a linux IRQ number |
| 163 | * @interrupt: GSI number. |
| 164 | * @flags: interrupt flags |
| 165 | * |
| 166 | * Returns: a valid linux IRQ number on success |
| 167 | * 0 or -EINVAL on failure |
| 168 | */ |
| 169 | static int pcc_map_interrupt(u32 interrupt, u32 flags) |
| 170 | { |
| 171 | int trigger, polarity; |
| 172 | |
| 173 | if (!interrupt) |
| 174 | return 0; |
| 175 | |
| 176 | trigger = (flags & ACPI_PCCT_INTERRUPT_MODE) ? ACPI_EDGE_SENSITIVE |
| 177 | : ACPI_LEVEL_SENSITIVE; |
| 178 | |
| 179 | polarity = (flags & ACPI_PCCT_INTERRUPT_POLARITY) ? ACPI_ACTIVE_LOW |
| 180 | : ACPI_ACTIVE_HIGH; |
| 181 | |
| 182 | return acpi_register_gsi(NULL, interrupt, trigger, polarity); |
| 183 | } |
| 184 | |
| 185 | /** |
| 186 | * pcc_mbox_irq - PCC mailbox interrupt handler |
| 187 | */ |
| 188 | static irqreturn_t pcc_mbox_irq(int irq, void *p) |
| 189 | { |
| 190 | struct acpi_generic_address *doorbell_ack; |
| 191 | struct acpi_pcct_hw_reduced *pcct_ss; |
| 192 | struct mbox_chan *chan = p; |
| 193 | u64 doorbell_ack_preserve; |
| 194 | u64 doorbell_ack_write; |
| 195 | u64 doorbell_ack_val; |
| 196 | int ret; |
| 197 | |
| 198 | pcct_ss = chan->con_priv; |
| 199 | |
| 200 | mbox_chan_received_data(chan, NULL); |
| 201 | |
| 202 | if (pcct_ss->header.type == ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE_TYPE2) { |
| 203 | struct acpi_pcct_hw_reduced_type2 *pcct2_ss = chan->con_priv; |
| 204 | u32 id = chan - pcc_mbox_channels; |
| 205 | |
David E. Box | c7a1dfb | 2017-06-05 16:39:08 +0800 | [diff] [blame] | 206 | doorbell_ack = &pcct2_ss->platform_ack_register; |
hotran | aca314e | 2016-08-15 17:14:05 -0700 | [diff] [blame] | 207 | doorbell_ack_preserve = pcct2_ss->ack_preserve_mask; |
| 208 | doorbell_ack_write = pcct2_ss->ack_write_mask; |
| 209 | |
| 210 | ret = read_register(pcc_doorbell_ack_vaddr[id], |
| 211 | &doorbell_ack_val, |
| 212 | doorbell_ack->bit_width); |
| 213 | if (ret) |
| 214 | return IRQ_NONE; |
| 215 | |
| 216 | ret = write_register(pcc_doorbell_ack_vaddr[id], |
| 217 | (doorbell_ack_val & doorbell_ack_preserve) |
| 218 | | doorbell_ack_write, |
| 219 | doorbell_ack->bit_width); |
| 220 | if (ret) |
| 221 | return IRQ_NONE; |
| 222 | } |
| 223 | |
| 224 | return IRQ_HANDLED; |
| 225 | } |
| 226 | |
| 227 | /** |
| 228 | * pcc_mbox_request_channel - PCC clients call this function to |
| 229 | * request a pointer to their PCC subspace, from which they |
| 230 | * can get the details of communicating with the remote. |
| 231 | * @cl: Pointer to Mailbox client, so we know where to bind the |
| 232 | * Channel. |
| 233 | * @subspace_id: The PCC Subspace index as parsed in the PCC client |
| 234 | * ACPI package. This is used to lookup the array of PCC |
| 235 | * subspaces as parsed by the PCC Mailbox controller. |
| 236 | * |
| 237 | * Return: Pointer to the Mailbox Channel if successful or |
| 238 | * ERR_PTR. |
| 239 | */ |
| 240 | struct mbox_chan *pcc_mbox_request_channel(struct mbox_client *cl, |
| 241 | int subspace_id) |
| 242 | { |
| 243 | struct device *dev = pcc_mbox_ctrl.dev; |
| 244 | struct mbox_chan *chan; |
| 245 | unsigned long flags; |
| 246 | |
| 247 | /* |
| 248 | * Each PCC Subspace is a Mailbox Channel. |
| 249 | * The PCC Clients get their PCC Subspace ID |
| 250 | * from their own tables and pass it here. |
| 251 | * This returns a pointer to the PCC subspace |
| 252 | * for the Client to operate on. |
| 253 | */ |
| 254 | chan = get_pcc_channel(subspace_id); |
| 255 | |
| 256 | if (IS_ERR(chan) || chan->cl) { |
| 257 | dev_err(dev, "Channel not found for idx: %d\n", subspace_id); |
| 258 | return ERR_PTR(-EBUSY); |
| 259 | } |
| 260 | |
| 261 | spin_lock_irqsave(&chan->lock, flags); |
| 262 | chan->msg_free = 0; |
| 263 | chan->msg_count = 0; |
| 264 | chan->active_req = NULL; |
| 265 | chan->cl = cl; |
| 266 | init_completion(&chan->tx_complete); |
| 267 | |
| 268 | if (chan->txdone_method == TXDONE_BY_POLL && cl->knows_txdone) |
| 269 | chan->txdone_method |= TXDONE_BY_ACK; |
| 270 | |
Hoan Tran | 6ca595a | 2016-11-14 11:19:02 -0800 | [diff] [blame] | 271 | spin_unlock_irqrestore(&chan->lock, flags); |
| 272 | |
hotran | aca314e | 2016-08-15 17:14:05 -0700 | [diff] [blame] | 273 | if (pcc_doorbell_irq[subspace_id] > 0) { |
| 274 | int rc; |
| 275 | |
| 276 | rc = devm_request_irq(dev, pcc_doorbell_irq[subspace_id], |
| 277 | pcc_mbox_irq, 0, MBOX_IRQ_NAME, chan); |
| 278 | if (unlikely(rc)) { |
| 279 | dev_err(dev, "failed to register PCC interrupt %d\n", |
| 280 | pcc_doorbell_irq[subspace_id]); |
Hoan Tran | 6ca595a | 2016-11-14 11:19:02 -0800 | [diff] [blame] | 281 | pcc_mbox_free_channel(chan); |
hotran | aca314e | 2016-08-15 17:14:05 -0700 | [diff] [blame] | 282 | chan = ERR_PTR(rc); |
| 283 | } |
| 284 | } |
| 285 | |
hotran | aca314e | 2016-08-15 17:14:05 -0700 | [diff] [blame] | 286 | return chan; |
| 287 | } |
| 288 | EXPORT_SYMBOL_GPL(pcc_mbox_request_channel); |
| 289 | |
| 290 | /** |
| 291 | * pcc_mbox_free_channel - Clients call this to free their Channel. |
| 292 | * |
| 293 | * @chan: Pointer to the mailbox channel as returned by |
| 294 | * pcc_mbox_request_channel() |
| 295 | */ |
| 296 | void pcc_mbox_free_channel(struct mbox_chan *chan) |
| 297 | { |
| 298 | u32 id = chan - pcc_mbox_channels; |
| 299 | unsigned long flags; |
| 300 | |
| 301 | if (!chan || !chan->cl) |
| 302 | return; |
| 303 | |
| 304 | if (id >= pcc_mbox_ctrl.num_chans) { |
| 305 | pr_debug("pcc_mbox_free_channel: Invalid mbox_chan passed\n"); |
| 306 | return; |
| 307 | } |
| 308 | |
Hoan Tran | 6ca595a | 2016-11-14 11:19:02 -0800 | [diff] [blame] | 309 | if (pcc_doorbell_irq[id] > 0) |
| 310 | devm_free_irq(chan->mbox->dev, pcc_doorbell_irq[id], chan); |
| 311 | |
hotran | aca314e | 2016-08-15 17:14:05 -0700 | [diff] [blame] | 312 | spin_lock_irqsave(&chan->lock, flags); |
| 313 | chan->cl = NULL; |
| 314 | chan->active_req = NULL; |
| 315 | if (chan->txdone_method == (TXDONE_BY_POLL | TXDONE_BY_ACK)) |
| 316 | chan->txdone_method = TXDONE_BY_POLL; |
| 317 | |
hotran | aca314e | 2016-08-15 17:14:05 -0700 | [diff] [blame] | 318 | spin_unlock_irqrestore(&chan->lock, flags); |
| 319 | } |
| 320 | EXPORT_SYMBOL_GPL(pcc_mbox_free_channel); |
| 321 | |
hotran | aca314e | 2016-08-15 17:14:05 -0700 | [diff] [blame] | 322 | /** |
Ashwin Chaugule | 33350e6 | 2015-01-27 16:03:57 -0500 | [diff] [blame] | 323 | * pcc_send_data - Called from Mailbox Controller code. Used |
| 324 | * here only to ring the channel doorbell. The PCC client |
| 325 | * specific read/write is done in the client driver in |
| 326 | * order to maintain atomicity over PCC channel once |
| 327 | * OS has control over it. See above for flow of operations. |
Ashwin Chaugule | 86c22f8 | 2014-11-12 19:59:38 -0500 | [diff] [blame] | 328 | * @chan: Pointer to Mailbox channel over which to send data. |
Ashwin Chaugule | 33350e6 | 2015-01-27 16:03:57 -0500 | [diff] [blame] | 329 | * @data: Client specific data written over channel. Used here |
| 330 | * only for debug after PCC transaction completes. |
Ashwin Chaugule | 86c22f8 | 2014-11-12 19:59:38 -0500 | [diff] [blame] | 331 | * |
| 332 | * Return: Err if something failed else 0 for success. |
| 333 | */ |
| 334 | static int pcc_send_data(struct mbox_chan *chan, void *data) |
| 335 | { |
| 336 | struct acpi_pcct_hw_reduced *pcct_ss = chan->con_priv; |
Prakash, Prashanth | 8b0f578 | 2016-02-17 13:21:01 -0700 | [diff] [blame] | 337 | struct acpi_generic_address *doorbell; |
Ashwin Chaugule | 86c22f8 | 2014-11-12 19:59:38 -0500 | [diff] [blame] | 338 | u64 doorbell_preserve; |
| 339 | u64 doorbell_val; |
| 340 | u64 doorbell_write; |
Prakash, Prashanth | 8b0f578 | 2016-02-17 13:21:01 -0700 | [diff] [blame] | 341 | u32 id = chan - pcc_mbox_channels; |
| 342 | int ret = 0; |
Ashwin Chaugule | 86c22f8 | 2014-11-12 19:59:38 -0500 | [diff] [blame] | 343 | |
Prakash, Prashanth | 8b0f578 | 2016-02-17 13:21:01 -0700 | [diff] [blame] | 344 | if (id >= pcc_mbox_ctrl.num_chans) { |
| 345 | pr_debug("pcc_send_data: Invalid mbox_chan passed\n"); |
| 346 | return -ENOENT; |
| 347 | } |
| 348 | |
| 349 | doorbell = &pcct_ss->doorbell_register; |
Ashwin Chaugule | 86c22f8 | 2014-11-12 19:59:38 -0500 | [diff] [blame] | 350 | doorbell_preserve = pcct_ss->preserve_mask; |
| 351 | doorbell_write = pcct_ss->write_mask; |
| 352 | |
Ashwin Chaugule | 33350e6 | 2015-01-27 16:03:57 -0500 | [diff] [blame] | 353 | /* Sync notification from OS to Platform. */ |
Prakash, Prashanth | 8b0f578 | 2016-02-17 13:21:01 -0700 | [diff] [blame] | 354 | if (pcc_doorbell_vaddr[id]) { |
| 355 | ret = read_register(pcc_doorbell_vaddr[id], &doorbell_val, |
| 356 | doorbell->bit_width); |
| 357 | if (ret) |
| 358 | return ret; |
| 359 | ret = write_register(pcc_doorbell_vaddr[id], |
| 360 | (doorbell_val & doorbell_preserve) | doorbell_write, |
| 361 | doorbell->bit_width); |
| 362 | } else { |
| 363 | ret = acpi_read(&doorbell_val, doorbell); |
| 364 | if (ret) |
| 365 | return ret; |
| 366 | ret = acpi_write((doorbell_val & doorbell_preserve) | doorbell_write, |
| 367 | doorbell); |
| 368 | } |
| 369 | return ret; |
Ashwin Chaugule | 86c22f8 | 2014-11-12 19:59:38 -0500 | [diff] [blame] | 370 | } |
| 371 | |
Andrew Bresticker | 05ae797 | 2015-05-04 10:36:35 -0700 | [diff] [blame] | 372 | static const struct mbox_chan_ops pcc_chan_ops = { |
Ashwin Chaugule | 86c22f8 | 2014-11-12 19:59:38 -0500 | [diff] [blame] | 373 | .send_data = pcc_send_data, |
Ashwin Chaugule | 86c22f8 | 2014-11-12 19:59:38 -0500 | [diff] [blame] | 374 | }; |
| 375 | |
| 376 | /** |
| 377 | * parse_pcc_subspace - Parse the PCC table and verify PCC subspace |
| 378 | * entries. There should be one entry per PCC client. |
| 379 | * @header: Pointer to the ACPI subtable header under the PCCT. |
| 380 | * @end: End of subtable entry. |
| 381 | * |
| 382 | * Return: 0 for Success, else errno. |
| 383 | * |
| 384 | * This gets called for each entry in the PCC table. |
| 385 | */ |
| 386 | static int parse_pcc_subspace(struct acpi_subtable_header *header, |
| 387 | const unsigned long end) |
| 388 | { |
| 389 | struct acpi_pcct_hw_reduced *pcct_ss; |
| 390 | |
| 391 | if (pcc_mbox_ctrl.num_chans <= MAX_PCC_SUBSPACES) { |
| 392 | pcct_ss = (struct acpi_pcct_hw_reduced *) header; |
| 393 | |
hotran | aca314e | 2016-08-15 17:14:05 -0700 | [diff] [blame] | 394 | if ((pcct_ss->header.type != |
| 395 | ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE) |
| 396 | && (pcct_ss->header.type != |
| 397 | ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE_TYPE2)) { |
Ashwin Chaugule | 86c22f8 | 2014-11-12 19:59:38 -0500 | [diff] [blame] | 398 | pr_err("Incorrect PCC Subspace type detected\n"); |
| 399 | return -EINVAL; |
| 400 | } |
| 401 | } |
| 402 | |
| 403 | return 0; |
| 404 | } |
| 405 | |
| 406 | /** |
hotran | aca314e | 2016-08-15 17:14:05 -0700 | [diff] [blame] | 407 | * pcc_parse_subspace_irq - Parse the PCC IRQ and PCC ACK register |
| 408 | * There should be one entry per PCC client. |
| 409 | * @id: PCC subspace index. |
| 410 | * @pcct_ss: Pointer to the ACPI subtable header under the PCCT. |
| 411 | * |
| 412 | * Return: 0 for Success, else errno. |
| 413 | * |
| 414 | * This gets called for each entry in the PCC table. |
| 415 | */ |
| 416 | static int pcc_parse_subspace_irq(int id, |
| 417 | struct acpi_pcct_hw_reduced *pcct_ss) |
| 418 | { |
David E. Box | c7a1dfb | 2017-06-05 16:39:08 +0800 | [diff] [blame] | 419 | pcc_doorbell_irq[id] = pcc_map_interrupt(pcct_ss->platform_interrupt, |
hotran | aca314e | 2016-08-15 17:14:05 -0700 | [diff] [blame] | 420 | (u32)pcct_ss->flags); |
| 421 | if (pcc_doorbell_irq[id] <= 0) { |
| 422 | pr_err("PCC GSI %d not registered\n", |
David E. Box | c7a1dfb | 2017-06-05 16:39:08 +0800 | [diff] [blame] | 423 | pcct_ss->platform_interrupt); |
hotran | aca314e | 2016-08-15 17:14:05 -0700 | [diff] [blame] | 424 | return -EINVAL; |
| 425 | } |
| 426 | |
| 427 | if (pcct_ss->header.type |
| 428 | == ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE_TYPE2) { |
| 429 | struct acpi_pcct_hw_reduced_type2 *pcct2_ss = (void *)pcct_ss; |
| 430 | |
| 431 | pcc_doorbell_ack_vaddr[id] = acpi_os_ioremap( |
David E. Box | c7a1dfb | 2017-06-05 16:39:08 +0800 | [diff] [blame] | 432 | pcct2_ss->platform_ack_register.address, |
| 433 | pcct2_ss->platform_ack_register.bit_width / 8); |
hotran | aca314e | 2016-08-15 17:14:05 -0700 | [diff] [blame] | 434 | if (!pcc_doorbell_ack_vaddr[id]) { |
| 435 | pr_err("Failed to ioremap PCC ACK register\n"); |
| 436 | return -ENOMEM; |
| 437 | } |
| 438 | } |
| 439 | |
| 440 | return 0; |
| 441 | } |
| 442 | |
| 443 | /** |
Ashwin Chaugule | 86c22f8 | 2014-11-12 19:59:38 -0500 | [diff] [blame] | 444 | * acpi_pcc_probe - Parse the ACPI tree for the PCCT. |
| 445 | * |
| 446 | * Return: 0 for Success, else errno. |
| 447 | */ |
| 448 | static int __init acpi_pcc_probe(void) |
| 449 | { |
Ashwin Chaugule | 86c22f8 | 2014-11-12 19:59:38 -0500 | [diff] [blame] | 450 | struct acpi_table_header *pcct_tbl; |
| 451 | struct acpi_subtable_header *pcct_entry; |
hotran | aca314e | 2016-08-15 17:14:05 -0700 | [diff] [blame] | 452 | struct acpi_table_pcct *acpi_pcct_tbl; |
| 453 | int count, i, rc; |
| 454 | int sum = 0; |
Ashwin Chaugule | 86c22f8 | 2014-11-12 19:59:38 -0500 | [diff] [blame] | 455 | acpi_status status = AE_OK; |
| 456 | |
| 457 | /* Search for PCCT */ |
Lv Zheng | 6b11d1d | 2016-12-14 15:04:39 +0800 | [diff] [blame] | 458 | status = acpi_get_table(ACPI_SIG_PCCT, 0, &pcct_tbl); |
Ashwin Chaugule | 86c22f8 | 2014-11-12 19:59:38 -0500 | [diff] [blame] | 459 | |
| 460 | if (ACPI_FAILURE(status) || !pcct_tbl) { |
| 461 | pr_warn("PCCT header not found.\n"); |
| 462 | return -ENODEV; |
| 463 | } |
| 464 | |
| 465 | count = acpi_table_parse_entries(ACPI_SIG_PCCT, |
| 466 | sizeof(struct acpi_table_pcct), |
| 467 | ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE, |
| 468 | parse_pcc_subspace, MAX_PCC_SUBSPACES); |
hotran | aca314e | 2016-08-15 17:14:05 -0700 | [diff] [blame] | 469 | sum += (count > 0) ? count : 0; |
Ashwin Chaugule | 86c22f8 | 2014-11-12 19:59:38 -0500 | [diff] [blame] | 470 | |
hotran | aca314e | 2016-08-15 17:14:05 -0700 | [diff] [blame] | 471 | count = acpi_table_parse_entries(ACPI_SIG_PCCT, |
| 472 | sizeof(struct acpi_table_pcct), |
| 473 | ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE_TYPE2, |
| 474 | parse_pcc_subspace, MAX_PCC_SUBSPACES); |
| 475 | sum += (count > 0) ? count : 0; |
| 476 | |
| 477 | if (sum == 0 || sum >= MAX_PCC_SUBSPACES) { |
Ashwin Chaugule | 86c22f8 | 2014-11-12 19:59:38 -0500 | [diff] [blame] | 478 | pr_err("Error parsing PCC subspaces from PCCT\n"); |
| 479 | return -EINVAL; |
| 480 | } |
| 481 | |
| 482 | pcc_mbox_channels = kzalloc(sizeof(struct mbox_chan) * |
hotran | aca314e | 2016-08-15 17:14:05 -0700 | [diff] [blame] | 483 | sum, GFP_KERNEL); |
Ashwin Chaugule | 86c22f8 | 2014-11-12 19:59:38 -0500 | [diff] [blame] | 484 | if (!pcc_mbox_channels) { |
| 485 | pr_err("Could not allocate space for PCC mbox channels\n"); |
| 486 | return -ENOMEM; |
| 487 | } |
| 488 | |
hotran | aca314e | 2016-08-15 17:14:05 -0700 | [diff] [blame] | 489 | pcc_doorbell_vaddr = kcalloc(sum, sizeof(void *), GFP_KERNEL); |
Prakash, Prashanth | 8b0f578 | 2016-02-17 13:21:01 -0700 | [diff] [blame] | 490 | if (!pcc_doorbell_vaddr) { |
hotran | aca314e | 2016-08-15 17:14:05 -0700 | [diff] [blame] | 491 | rc = -ENOMEM; |
| 492 | goto err_free_mbox; |
| 493 | } |
| 494 | |
| 495 | pcc_doorbell_ack_vaddr = kcalloc(sum, sizeof(void *), GFP_KERNEL); |
| 496 | if (!pcc_doorbell_ack_vaddr) { |
| 497 | rc = -ENOMEM; |
| 498 | goto err_free_db_vaddr; |
| 499 | } |
| 500 | |
| 501 | pcc_doorbell_irq = kcalloc(sum, sizeof(int), GFP_KERNEL); |
| 502 | if (!pcc_doorbell_irq) { |
| 503 | rc = -ENOMEM; |
| 504 | goto err_free_db_ack_vaddr; |
Prakash, Prashanth | 8b0f578 | 2016-02-17 13:21:01 -0700 | [diff] [blame] | 505 | } |
| 506 | |
Ashwin Chaugule | 86c22f8 | 2014-11-12 19:59:38 -0500 | [diff] [blame] | 507 | /* Point to the first PCC subspace entry */ |
| 508 | pcct_entry = (struct acpi_subtable_header *) ( |
| 509 | (unsigned long) pcct_tbl + sizeof(struct acpi_table_pcct)); |
| 510 | |
hotran | aca314e | 2016-08-15 17:14:05 -0700 | [diff] [blame] | 511 | acpi_pcct_tbl = (struct acpi_table_pcct *) pcct_tbl; |
| 512 | if (acpi_pcct_tbl->flags & ACPI_PCCT_DOORBELL) |
| 513 | pcc_mbox_ctrl.txdone_irq = true; |
| 514 | |
| 515 | for (i = 0; i < sum; i++) { |
Prakash, Prashanth | 8b0f578 | 2016-02-17 13:21:01 -0700 | [diff] [blame] | 516 | struct acpi_generic_address *db_reg; |
| 517 | struct acpi_pcct_hw_reduced *pcct_ss; |
Ashwin Chaugule | 86c22f8 | 2014-11-12 19:59:38 -0500 | [diff] [blame] | 518 | pcc_mbox_channels[i].con_priv = pcct_entry; |
Prakash, Prashanth | 8b0f578 | 2016-02-17 13:21:01 -0700 | [diff] [blame] | 519 | |
hotran | aca314e | 2016-08-15 17:14:05 -0700 | [diff] [blame] | 520 | pcct_ss = (struct acpi_pcct_hw_reduced *) pcct_entry; |
| 521 | |
| 522 | if (pcc_mbox_ctrl.txdone_irq) { |
| 523 | rc = pcc_parse_subspace_irq(i, pcct_ss); |
| 524 | if (rc < 0) |
| 525 | goto err; |
| 526 | } |
| 527 | |
Prakash, Prashanth | 8b0f578 | 2016-02-17 13:21:01 -0700 | [diff] [blame] | 528 | /* If doorbell is in system memory cache the virt address */ |
Prakash, Prashanth | 8b0f578 | 2016-02-17 13:21:01 -0700 | [diff] [blame] | 529 | db_reg = &pcct_ss->doorbell_register; |
| 530 | if (db_reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) |
| 531 | pcc_doorbell_vaddr[i] = acpi_os_ioremap(db_reg->address, |
| 532 | db_reg->bit_width/8); |
Ashwin Chaugule | 86c22f8 | 2014-11-12 19:59:38 -0500 | [diff] [blame] | 533 | pcct_entry = (struct acpi_subtable_header *) |
| 534 | ((unsigned long) pcct_entry + pcct_entry->length); |
| 535 | } |
| 536 | |
hotran | aca314e | 2016-08-15 17:14:05 -0700 | [diff] [blame] | 537 | pcc_mbox_ctrl.num_chans = sum; |
Ashwin Chaugule | 86c22f8 | 2014-11-12 19:59:38 -0500 | [diff] [blame] | 538 | |
| 539 | pr_info("Detected %d PCC Subspaces\n", pcc_mbox_ctrl.num_chans); |
| 540 | |
| 541 | return 0; |
hotran | aca314e | 2016-08-15 17:14:05 -0700 | [diff] [blame] | 542 | |
| 543 | err: |
| 544 | kfree(pcc_doorbell_irq); |
| 545 | err_free_db_ack_vaddr: |
| 546 | kfree(pcc_doorbell_ack_vaddr); |
| 547 | err_free_db_vaddr: |
| 548 | kfree(pcc_doorbell_vaddr); |
| 549 | err_free_mbox: |
| 550 | kfree(pcc_mbox_channels); |
| 551 | return rc; |
Ashwin Chaugule | 86c22f8 | 2014-11-12 19:59:38 -0500 | [diff] [blame] | 552 | } |
| 553 | |
| 554 | /** |
| 555 | * pcc_mbox_probe - Called when we find a match for the |
| 556 | * PCCT platform device. This is purely used to represent |
| 557 | * the PCCT as a virtual device for registering with the |
| 558 | * generic Mailbox framework. |
| 559 | * |
| 560 | * @pdev: Pointer to platform device returned when a match |
| 561 | * is found. |
| 562 | * |
| 563 | * Return: 0 for Success, else errno. |
| 564 | */ |
| 565 | static int pcc_mbox_probe(struct platform_device *pdev) |
| 566 | { |
| 567 | int ret = 0; |
| 568 | |
| 569 | pcc_mbox_ctrl.chans = pcc_mbox_channels; |
| 570 | pcc_mbox_ctrl.ops = &pcc_chan_ops; |
Ashwin Chaugule | 86c22f8 | 2014-11-12 19:59:38 -0500 | [diff] [blame] | 571 | pcc_mbox_ctrl.dev = &pdev->dev; |
| 572 | |
| 573 | pr_info("Registering PCC driver as Mailbox controller\n"); |
| 574 | ret = mbox_controller_register(&pcc_mbox_ctrl); |
| 575 | |
| 576 | if (ret) { |
| 577 | pr_err("Err registering PCC as Mailbox controller: %d\n", ret); |
| 578 | ret = -ENODEV; |
| 579 | } |
| 580 | |
| 581 | return ret; |
| 582 | } |
| 583 | |
| 584 | struct platform_driver pcc_mbox_driver = { |
| 585 | .probe = pcc_mbox_probe, |
| 586 | .driver = { |
| 587 | .name = "PCCT", |
| 588 | .owner = THIS_MODULE, |
| 589 | }, |
| 590 | }; |
| 591 | |
| 592 | static int __init pcc_init(void) |
| 593 | { |
| 594 | int ret; |
| 595 | struct platform_device *pcc_pdev; |
| 596 | |
| 597 | if (acpi_disabled) |
| 598 | return -ENODEV; |
| 599 | |
| 600 | /* Check if PCC support is available. */ |
| 601 | ret = acpi_pcc_probe(); |
| 602 | |
| 603 | if (ret) { |
Rafael J. Wysocki | efd756d | 2015-02-05 00:40:08 +0100 | [diff] [blame] | 604 | pr_debug("ACPI PCC probe failed.\n"); |
Ashwin Chaugule | 86c22f8 | 2014-11-12 19:59:38 -0500 | [diff] [blame] | 605 | return -ENODEV; |
| 606 | } |
| 607 | |
| 608 | pcc_pdev = platform_create_bundle(&pcc_mbox_driver, |
| 609 | pcc_mbox_probe, NULL, 0, NULL, 0); |
| 610 | |
Wei Yongjun | 356d5d2 | 2015-01-14 09:10:56 +0800 | [diff] [blame] | 611 | if (IS_ERR(pcc_pdev)) { |
Rafael J. Wysocki | efd756d | 2015-02-05 00:40:08 +0100 | [diff] [blame] | 612 | pr_debug("Err creating PCC platform bundle\n"); |
Wei Yongjun | 356d5d2 | 2015-01-14 09:10:56 +0800 | [diff] [blame] | 613 | return PTR_ERR(pcc_pdev); |
Ashwin Chaugule | 86c22f8 | 2014-11-12 19:59:38 -0500 | [diff] [blame] | 614 | } |
| 615 | |
| 616 | return 0; |
| 617 | } |
Ashwin Chaugule | d3c68f2 | 2015-08-05 09:40:24 -0400 | [diff] [blame] | 618 | |
| 619 | /* |
| 620 | * Make PCC init postcore so that users of this mailbox |
| 621 | * such as the ACPI Processor driver have it available |
| 622 | * at their init. |
| 623 | */ |
| 624 | postcore_initcall(pcc_init); |