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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Copyright 2014 IBM Corp.4 */5 6#include <linux/spinlock.h>7#include <linux/module.h>8#include <linux/export.h>9#include <linux/kernel.h>10#include <linux/bitmap.h>11#include <linux/sched/signal.h>12#include <linux/poll.h>13#include <linux/pid.h>14#include <linux/fs.h>15#include <linux/mm.h>16#include <linux/slab.h>17#include <linux/sched/mm.h>18#include <linux/mmu_context.h>19#include <asm/cputable.h>20#include <asm/current.h>21#include <asm/copro.h>22 23#include "cxl.h"24#include "trace.h"25 26#define CXL_NUM_MINORS 256 /* Total to reserve */27 28#define CXL_AFU_MINOR_D(afu) (CXL_CARD_MINOR(afu->adapter) + 1 + (3 * afu->slice))29#define CXL_AFU_MINOR_M(afu) (CXL_AFU_MINOR_D(afu) + 1)30#define CXL_AFU_MINOR_S(afu) (CXL_AFU_MINOR_D(afu) + 2)31#define CXL_AFU_MKDEV_D(afu) MKDEV(MAJOR(cxl_dev), CXL_AFU_MINOR_D(afu))32#define CXL_AFU_MKDEV_M(afu) MKDEV(MAJOR(cxl_dev), CXL_AFU_MINOR_M(afu))33#define CXL_AFU_MKDEV_S(afu) MKDEV(MAJOR(cxl_dev), CXL_AFU_MINOR_S(afu))34 35#define CXL_DEVT_AFU(dev) ((MINOR(dev) % CXL_DEV_MINORS - 1) / 3)36 37#define CXL_DEVT_IS_CARD(dev) (MINOR(dev) % CXL_DEV_MINORS == 0)38 39static dev_t cxl_dev;40 41static int __afu_open(struct inode *inode, struct file *file, bool master)42{43 struct cxl *adapter;44 struct cxl_afu *afu;45 struct cxl_context *ctx;46 int adapter_num = CXL_DEVT_ADAPTER(inode->i_rdev);47 int slice = CXL_DEVT_AFU(inode->i_rdev);48 int rc = -ENODEV;49 50 pr_devel("afu_open afu%i.%i\n", slice, adapter_num);51 52 if (!(adapter = get_cxl_adapter(adapter_num)))53 return -ENODEV;54 55 if (slice > adapter->slices)56 goto err_put_adapter;57 58 spin_lock(&adapter->afu_list_lock);59 if (!(afu = adapter->afu[slice])) {60 spin_unlock(&adapter->afu_list_lock);61 goto err_put_adapter;62 }63 64 /*65 * taking a ref to the afu so that it doesn't go away66 * for rest of the function. This ref is released before67 * we return.68 */69 cxl_afu_get(afu);70 spin_unlock(&adapter->afu_list_lock);71 72 if (!afu->current_mode)73 goto err_put_afu;74 75 if (!cxl_ops->link_ok(adapter, afu)) {76 rc = -EIO;77 goto err_put_afu;78 }79 80 if (!(ctx = cxl_context_alloc())) {81 rc = -ENOMEM;82 goto err_put_afu;83 }84 85 rc = cxl_context_init(ctx, afu, master);86 if (rc)87 goto err_put_afu;88 89 cxl_context_set_mapping(ctx, inode->i_mapping);90 91 pr_devel("afu_open pe: %i\n", ctx->pe);92 file->private_data = ctx;93 94 /* indicate success */95 rc = 0;96 97err_put_afu:98 /* release the ref taken earlier */99 cxl_afu_put(afu);100err_put_adapter:101 put_device(&adapter->dev);102 return rc;103}104 105int afu_open(struct inode *inode, struct file *file)106{107 return __afu_open(inode, file, false);108}109 110static int afu_master_open(struct inode *inode, struct file *file)111{112 return __afu_open(inode, file, true);113}114 115int afu_release(struct inode *inode, struct file *file)116{117 struct cxl_context *ctx = file->private_data;118 119 pr_devel("%s: closing cxl file descriptor. pe: %i\n",120 __func__, ctx->pe);121 cxl_context_detach(ctx);122 123 124 /*125 * Delete the context's mapping pointer, unless it's created by the126 * kernel API, in which case leave it so it can be freed by reclaim_ctx()127 */128 if (!ctx->kernelapi) {129 mutex_lock(&ctx->mapping_lock);130 ctx->mapping = NULL;131 mutex_unlock(&ctx->mapping_lock);132 }133 134 /*135 * At this this point all bottom halfs have finished and we should be136 * getting no more IRQs from the hardware for this context. Once it's137 * removed from the IDR (and RCU synchronised) it's safe to free the138 * sstp and context.139 */140 cxl_context_free(ctx);141 142 return 0;143}144 145static long afu_ioctl_start_work(struct cxl_context *ctx,146 struct cxl_ioctl_start_work __user *uwork)147{148 struct cxl_ioctl_start_work work;149 u64 amr = 0;150 int rc;151 152 pr_devel("%s: pe: %i\n", __func__, ctx->pe);153 154 /* Do this outside the status_mutex to avoid a circular dependency with155 * the locking in cxl_mmap_fault() */156 if (copy_from_user(&work, uwork, sizeof(work)))157 return -EFAULT;158 159 mutex_lock(&ctx->status_mutex);160 if (ctx->status != OPENED) {161 rc = -EIO;162 goto out;163 }164 165 /*166 * if any of the reserved fields are set or any of the unused167 * flags are set it's invalid168 */169 if (work.reserved1 || work.reserved2 || work.reserved3 ||170 work.reserved4 || work.reserved5 ||171 (work.flags & ~CXL_START_WORK_ALL)) {172 rc = -EINVAL;173 goto out;174 }175 176 if (!(work.flags & CXL_START_WORK_NUM_IRQS))177 work.num_interrupts = ctx->afu->pp_irqs;178 else if ((work.num_interrupts < ctx->afu->pp_irqs) ||179 (work.num_interrupts > ctx->afu->irqs_max)) {180 rc = -EINVAL;181 goto out;182 }183 184 if ((rc = afu_register_irqs(ctx, work.num_interrupts)))185 goto out;186 187 if (work.flags & CXL_START_WORK_AMR)188 amr = work.amr & mfspr(SPRN_UAMOR);189 190 if (work.flags & CXL_START_WORK_TID)191 ctx->assign_tidr = true;192 193 ctx->mmio_err_ff = !!(work.flags & CXL_START_WORK_ERR_FF);194 195 /*196 * Increment the mapped context count for adapter. This also checks197 * if adapter_context_lock is taken.198 */199 rc = cxl_adapter_context_get(ctx->afu->adapter);200 if (rc) {201 afu_release_irqs(ctx, ctx);202 goto out;203 }204 205 /*206 * We grab the PID here and not in the file open to allow for the case207 * where a process (master, some daemon, etc) has opened the chardev on208 * behalf of another process, so the AFU's mm gets bound to the process209 * that performs this ioctl and not the process that opened the file.210 * Also we grab the PID of the group leader so that if the task that211 * has performed the attach operation exits the mm context of the212 * process is still accessible.213 */214 ctx->pid = get_task_pid(current, PIDTYPE_PID);215 216 /* acquire a reference to the task's mm */217 ctx->mm = get_task_mm(current);218 219 /* ensure this mm_struct can't be freed */220 cxl_context_mm_count_get(ctx);221 222 if (ctx->mm) {223 /* decrement the use count from above */224 mmput(ctx->mm);225 /* make TLBIs for this context global */226 mm_context_add_copro(ctx->mm);227 }228 229 /*230 * Increment driver use count. Enables global TLBIs for hash231 * and callbacks to handle the segment table232 */233 cxl_ctx_get();234 235 /*236 * A barrier is needed to make sure all TLBIs are global237 * before we attach and the context starts being used by the238 * adapter.239 *240 * Needed after mm_context_add_copro() for radix and241 * cxl_ctx_get() for hash/p8.242 *243 * The barrier should really be mb(), since it involves a244 * device. However, it's only useful when we have local245 * vs. global TLBIs, i.e SMP=y. So keep smp_mb().246 */247 smp_mb();248 249 trace_cxl_attach(ctx, work.work_element_descriptor, work.num_interrupts, amr);250 251 if ((rc = cxl_ops->attach_process(ctx, false, work.work_element_descriptor,252 amr))) {253 afu_release_irqs(ctx, ctx);254 cxl_adapter_context_put(ctx->afu->adapter);255 put_pid(ctx->pid);256 ctx->pid = NULL;257 cxl_ctx_put();258 cxl_context_mm_count_put(ctx);259 if (ctx->mm)260 mm_context_remove_copro(ctx->mm);261 goto out;262 }263 264 rc = 0;265 if (work.flags & CXL_START_WORK_TID) {266 work.tid = ctx->tidr;267 if (copy_to_user(uwork, &work, sizeof(work)))268 rc = -EFAULT;269 }270 271 ctx->status = STARTED;272 273out:274 mutex_unlock(&ctx->status_mutex);275 return rc;276}277 278static long afu_ioctl_process_element(struct cxl_context *ctx,279 int __user *upe)280{281 pr_devel("%s: pe: %i\n", __func__, ctx->pe);282 283 if (copy_to_user(upe, &ctx->external_pe, sizeof(__u32)))284 return -EFAULT;285 286 return 0;287}288 289static long afu_ioctl_get_afu_id(struct cxl_context *ctx,290 struct cxl_afu_id __user *upafuid)291{292 struct cxl_afu_id afuid = { 0 };293 294 afuid.card_id = ctx->afu->adapter->adapter_num;295 afuid.afu_offset = ctx->afu->slice;296 afuid.afu_mode = ctx->afu->current_mode;297 298 /* set the flag bit in case the afu is a slave */299 if (ctx->afu->current_mode == CXL_MODE_DIRECTED && !ctx->master)300 afuid.flags |= CXL_AFUID_FLAG_SLAVE;301 302 if (copy_to_user(upafuid, &afuid, sizeof(afuid)))303 return -EFAULT;304 305 return 0;306}307 308long afu_ioctl(struct file *file, unsigned int cmd, unsigned long arg)309{310 struct cxl_context *ctx = file->private_data;311 312 if (ctx->status == CLOSED)313 return -EIO;314 315 if (!cxl_ops->link_ok(ctx->afu->adapter, ctx->afu))316 return -EIO;317 318 pr_devel("afu_ioctl\n");319 switch (cmd) {320 case CXL_IOCTL_START_WORK:321 return afu_ioctl_start_work(ctx, (struct cxl_ioctl_start_work __user *)arg);322 case CXL_IOCTL_GET_PROCESS_ELEMENT:323 return afu_ioctl_process_element(ctx, (__u32 __user *)arg);324 case CXL_IOCTL_GET_AFU_ID:325 return afu_ioctl_get_afu_id(ctx, (struct cxl_afu_id __user *)326 arg);327 }328 return -EINVAL;329}330 331static long afu_compat_ioctl(struct file *file, unsigned int cmd,332 unsigned long arg)333{334 return afu_ioctl(file, cmd, arg);335}336 337int afu_mmap(struct file *file, struct vm_area_struct *vm)338{339 struct cxl_context *ctx = file->private_data;340 341 /* AFU must be started before we can MMIO */342 if (ctx->status != STARTED)343 return -EIO;344 345 if (!cxl_ops->link_ok(ctx->afu->adapter, ctx->afu))346 return -EIO;347 348 return cxl_context_iomap(ctx, vm);349}350 351static inline bool ctx_event_pending(struct cxl_context *ctx)352{353 if (ctx->pending_irq || ctx->pending_fault || ctx->pending_afu_err)354 return true;355 356 if (ctx->afu_driver_ops && atomic_read(&ctx->afu_driver_events))357 return true;358 359 return false;360}361 362__poll_t afu_poll(struct file *file, struct poll_table_struct *poll)363{364 struct cxl_context *ctx = file->private_data;365 __poll_t mask = 0;366 unsigned long flags;367 368 369 poll_wait(file, &ctx->wq, poll);370 371 pr_devel("afu_poll wait done pe: %i\n", ctx->pe);372 373 spin_lock_irqsave(&ctx->lock, flags);374 if (ctx_event_pending(ctx))375 mask |= EPOLLIN | EPOLLRDNORM;376 else if (ctx->status == CLOSED)377 /* Only error on closed when there are no futher events pending378 */379 mask |= EPOLLERR;380 spin_unlock_irqrestore(&ctx->lock, flags);381 382 pr_devel("afu_poll pe: %i returning %#x\n", ctx->pe, mask);383 384 return mask;385}386 387static ssize_t afu_driver_event_copy(struct cxl_context *ctx,388 char __user *buf,389 struct cxl_event *event,390 struct cxl_event_afu_driver_reserved *pl)391{392 /* Check event */393 if (!pl) {394 ctx->afu_driver_ops->event_delivered(ctx, pl, -EINVAL);395 return -EFAULT;396 }397 398 /* Check event size */399 event->header.size += pl->data_size;400 if (event->header.size > CXL_READ_MIN_SIZE) {401 ctx->afu_driver_ops->event_delivered(ctx, pl, -EINVAL);402 return -EFAULT;403 }404 405 /* Copy event header */406 if (copy_to_user(buf, event, sizeof(struct cxl_event_header))) {407 ctx->afu_driver_ops->event_delivered(ctx, pl, -EFAULT);408 return -EFAULT;409 }410 411 /* Copy event data */412 buf += sizeof(struct cxl_event_header);413 if (copy_to_user(buf, &pl->data, pl->data_size)) {414 ctx->afu_driver_ops->event_delivered(ctx, pl, -EFAULT);415 return -EFAULT;416 }417 418 ctx->afu_driver_ops->event_delivered(ctx, pl, 0); /* Success */419 return event->header.size;420}421 422ssize_t afu_read(struct file *file, char __user *buf, size_t count,423 loff_t *off)424{425 struct cxl_context *ctx = file->private_data;426 struct cxl_event_afu_driver_reserved *pl = NULL;427 struct cxl_event event;428 unsigned long flags;429 int rc;430 DEFINE_WAIT(wait);431 432 if (!cxl_ops->link_ok(ctx->afu->adapter, ctx->afu))433 return -EIO;434 435 if (count < CXL_READ_MIN_SIZE)436 return -EINVAL;437 438 spin_lock_irqsave(&ctx->lock, flags);439 440 for (;;) {441 prepare_to_wait(&ctx->wq, &wait, TASK_INTERRUPTIBLE);442 if (ctx_event_pending(ctx) || (ctx->status == CLOSED))443 break;444 445 if (!cxl_ops->link_ok(ctx->afu->adapter, ctx->afu)) {446 rc = -EIO;447 goto out;448 }449 450 if (file->f_flags & O_NONBLOCK) {451 rc = -EAGAIN;452 goto out;453 }454 455 if (signal_pending(current)) {456 rc = -ERESTARTSYS;457 goto out;458 }459 460 spin_unlock_irqrestore(&ctx->lock, flags);461 pr_devel("afu_read going to sleep...\n");462 schedule();463 pr_devel("afu_read woken up\n");464 spin_lock_irqsave(&ctx->lock, flags);465 }466 467 finish_wait(&ctx->wq, &wait);468 469 memset(&event, 0, sizeof(event));470 event.header.process_element = ctx->pe;471 event.header.size = sizeof(struct cxl_event_header);472 if (ctx->afu_driver_ops && atomic_read(&ctx->afu_driver_events)) {473 pr_devel("afu_read delivering AFU driver specific event\n");474 pl = ctx->afu_driver_ops->fetch_event(ctx);475 atomic_dec(&ctx->afu_driver_events);476 event.header.type = CXL_EVENT_AFU_DRIVER;477 } else if (ctx->pending_irq) {478 pr_devel("afu_read delivering AFU interrupt\n");479 event.header.size += sizeof(struct cxl_event_afu_interrupt);480 event.header.type = CXL_EVENT_AFU_INTERRUPT;481 event.irq.irq = find_first_bit(ctx->irq_bitmap, ctx->irq_count) + 1;482 clear_bit(event.irq.irq - 1, ctx->irq_bitmap);483 if (bitmap_empty(ctx->irq_bitmap, ctx->irq_count))484 ctx->pending_irq = false;485 } else if (ctx->pending_fault) {486 pr_devel("afu_read delivering data storage fault\n");487 event.header.size += sizeof(struct cxl_event_data_storage);488 event.header.type = CXL_EVENT_DATA_STORAGE;489 event.fault.addr = ctx->fault_addr;490 event.fault.dsisr = ctx->fault_dsisr;491 ctx->pending_fault = false;492 } else if (ctx->pending_afu_err) {493 pr_devel("afu_read delivering afu error\n");494 event.header.size += sizeof(struct cxl_event_afu_error);495 event.header.type = CXL_EVENT_AFU_ERROR;496 event.afu_error.error = ctx->afu_err;497 ctx->pending_afu_err = false;498 } else if (ctx->status == CLOSED) {499 pr_devel("afu_read fatal error\n");500 spin_unlock_irqrestore(&ctx->lock, flags);501 return -EIO;502 } else503 WARN(1, "afu_read must be buggy\n");504 505 spin_unlock_irqrestore(&ctx->lock, flags);506 507 if (event.header.type == CXL_EVENT_AFU_DRIVER)508 return afu_driver_event_copy(ctx, buf, &event, pl);509 510 if (copy_to_user(buf, &event, event.header.size))511 return -EFAULT;512 return event.header.size;513 514out:515 finish_wait(&ctx->wq, &wait);516 spin_unlock_irqrestore(&ctx->lock, flags);517 return rc;518}519 520/* 521 * Note: if this is updated, we need to update api.c to patch the new ones in522 * too523 */524const struct file_operations afu_fops = {525 .owner = THIS_MODULE,526 .open = afu_open,527 .poll = afu_poll,528 .read = afu_read,529 .release = afu_release,530 .unlocked_ioctl = afu_ioctl,531 .compat_ioctl = afu_compat_ioctl,532 .mmap = afu_mmap,533};534 535static const struct file_operations afu_master_fops = {536 .owner = THIS_MODULE,537 .open = afu_master_open,538 .poll = afu_poll,539 .read = afu_read,540 .release = afu_release,541 .unlocked_ioctl = afu_ioctl,542 .compat_ioctl = afu_compat_ioctl,543 .mmap = afu_mmap,544};545 546 547static char *cxl_devnode(const struct device *dev, umode_t *mode)548{549 if (cpu_has_feature(CPU_FTR_HVMODE) &&550 CXL_DEVT_IS_CARD(dev->devt)) {551 /*552 * These minor numbers will eventually be used to program the553 * PSL and AFUs once we have dynamic reprogramming support554 */555 return NULL;556 }557 return kasprintf(GFP_KERNEL, "cxl/%s", dev_name(dev));558}559 560static const struct class cxl_class = {561 .name = "cxl",562 .devnode = cxl_devnode,563};564 565static int cxl_add_chardev(struct cxl_afu *afu, dev_t devt, struct cdev *cdev,566 struct device **chardev, char *postfix, char *desc,567 const struct file_operations *fops)568{569 struct device *dev;570 int rc;571 572 cdev_init(cdev, fops);573 rc = cdev_add(cdev, devt, 1);574 if (rc) {575 dev_err(&afu->dev, "Unable to add %s chardev: %i\n", desc, rc);576 return rc;577 }578 579 dev = device_create(&cxl_class, &afu->dev, devt, afu,580 "afu%i.%i%s", afu->adapter->adapter_num, afu->slice, postfix);581 if (IS_ERR(dev)) {582 rc = PTR_ERR(dev);583 dev_err(&afu->dev, "Unable to create %s chardev in sysfs: %i\n", desc, rc);584 goto err;585 }586 587 *chardev = dev;588 589 return 0;590err:591 cdev_del(cdev);592 return rc;593}594 595int cxl_chardev_d_afu_add(struct cxl_afu *afu)596{597 return cxl_add_chardev(afu, CXL_AFU_MKDEV_D(afu), &afu->afu_cdev_d,598 &afu->chardev_d, "d", "dedicated",599 &afu_master_fops); /* Uses master fops */600}601 602int cxl_chardev_m_afu_add(struct cxl_afu *afu)603{604 return cxl_add_chardev(afu, CXL_AFU_MKDEV_M(afu), &afu->afu_cdev_m,605 &afu->chardev_m, "m", "master",606 &afu_master_fops);607}608 609int cxl_chardev_s_afu_add(struct cxl_afu *afu)610{611 return cxl_add_chardev(afu, CXL_AFU_MKDEV_S(afu), &afu->afu_cdev_s,612 &afu->chardev_s, "s", "shared",613 &afu_fops);614}615 616void cxl_chardev_afu_remove(struct cxl_afu *afu)617{618 if (afu->chardev_d) {619 cdev_del(&afu->afu_cdev_d);620 device_unregister(afu->chardev_d);621 afu->chardev_d = NULL;622 }623 if (afu->chardev_m) {624 cdev_del(&afu->afu_cdev_m);625 device_unregister(afu->chardev_m);626 afu->chardev_m = NULL;627 }628 if (afu->chardev_s) {629 cdev_del(&afu->afu_cdev_s);630 device_unregister(afu->chardev_s);631 afu->chardev_s = NULL;632 }633}634 635int cxl_register_afu(struct cxl_afu *afu)636{637 afu->dev.class = &cxl_class;638 639 return device_register(&afu->dev);640}641 642int cxl_register_adapter(struct cxl *adapter)643{644 adapter->dev.class = &cxl_class;645 646 /*647 * Future: When we support dynamically reprogramming the PSL & AFU we648 * will expose the interface to do that via a chardev:649 * adapter->dev.devt = CXL_CARD_MKDEV(adapter);650 */651 652 return device_register(&adapter->dev);653}654 655dev_t cxl_get_dev(void)656{657 return cxl_dev;658}659 660int __init cxl_file_init(void)661{662 int rc;663 664 /*665 * If these change we really need to update API. Either change some666 * flags or update API version number CXL_API_VERSION.667 */668 BUILD_BUG_ON(CXL_API_VERSION != 3);669 BUILD_BUG_ON(sizeof(struct cxl_ioctl_start_work) != 64);670 BUILD_BUG_ON(sizeof(struct cxl_event_header) != 8);671 BUILD_BUG_ON(sizeof(struct cxl_event_afu_interrupt) != 8);672 BUILD_BUG_ON(sizeof(struct cxl_event_data_storage) != 32);673 BUILD_BUG_ON(sizeof(struct cxl_event_afu_error) != 16);674 675 if ((rc = alloc_chrdev_region(&cxl_dev, 0, CXL_NUM_MINORS, "cxl"))) {676 pr_err("Unable to allocate CXL major number: %i\n", rc);677 return rc;678 }679 680 pr_devel("CXL device allocated, MAJOR %i\n", MAJOR(cxl_dev));681 682 rc = class_register(&cxl_class);683 if (rc) {684 pr_err("Unable to create CXL class\n");685 goto err;686 }687 688 return 0;689 690err:691 unregister_chrdev_region(cxl_dev, CXL_NUM_MINORS);692 return rc;693}694 695void cxl_file_exit(void)696{697 unregister_chrdev_region(cxl_dev, CXL_NUM_MINORS);698 class_unregister(&cxl_class);699}700