2 * CXL Flash Device Driver
4 * Written by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>, IBM Corporation
5 * Matthew R. Ochs <mrochs@linux.vnet.ibm.com>, IBM Corporation
7 * Copyright (C) 2015 IBM Corporation
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License
11 * as published by the Free Software Foundation; either version
12 * 2 of the License, or (at your option) any later version.
15 #include <linux/delay.h>
16 #include <linux/file.h>
17 #include <linux/syscalls.h>
19 #include <asm/unaligned.h>
21 #include <scsi/scsi.h>
22 #include <scsi/scsi_host.h>
23 #include <scsi/scsi_cmnd.h>
24 #include <scsi/scsi_eh.h>
25 #include <uapi/scsi/cxlflash_ioctl.h>
30 #include "superpipe.h"
32 struct cxlflash_global global;
35 * marshal_rele_to_resize() - translate release to resize structure
36 * @rele: Source structure from which to translate/copy.
37 * @resize: Destination structure for the translate/copy.
39 static void marshal_rele_to_resize(struct dk_cxlflash_release *release,
40 struct dk_cxlflash_resize *resize)
42 resize->hdr = release->hdr;
43 resize->context_id = release->context_id;
44 resize->rsrc_handle = release->rsrc_handle;
48 * marshal_det_to_rele() - translate detach to release structure
49 * @detach: Destination structure for the translate/copy.
50 * @rele: Source structure from which to translate/copy.
52 static void marshal_det_to_rele(struct dk_cxlflash_detach *detach,
53 struct dk_cxlflash_release *release)
55 release->hdr = detach->hdr;
56 release->context_id = detach->context_id;
60 * cxlflash_free_errpage() - frees resources associated with global error page
62 void cxlflash_free_errpage(void)
65 mutex_lock(&global.mutex);
66 if (global.err_page) {
67 __free_page(global.err_page);
68 global.err_page = NULL;
70 mutex_unlock(&global.mutex);
74 * cxlflash_stop_term_user_contexts() - stops/terminates known user contexts
75 * @cfg: Internal structure associated with the host.
77 * When the host needs to go down, all users must be quiesced and their
78 * memory freed. This is accomplished by putting the contexts in error
79 * state which will notify the user and let them 'drive' the tear down.
80 * Meanwhile, this routine camps until all user contexts have been removed.
82 void cxlflash_stop_term_user_contexts(struct cxlflash_cfg *cfg)
84 struct device *dev = &cfg->dev->dev;
87 cxlflash_mark_contexts_error(cfg);
92 for (i = 0; i < MAX_CONTEXT; i++)
93 if (cfg->ctx_tbl[i]) {
98 if (!found && list_empty(&cfg->ctx_err_recovery))
101 dev_dbg(dev, "%s: Wait for user contexts to quiesce...\n",
103 wake_up_all(&cfg->reset_waitq);
109 * find_error_context() - locates a context by cookie on the error recovery list
110 * @cfg: Internal structure associated with the host.
111 * @rctxid: Desired context by id.
112 * @file: Desired context by file.
114 * Return: Found context on success, NULL on failure
116 static struct ctx_info *find_error_context(struct cxlflash_cfg *cfg, u64 rctxid,
119 struct ctx_info *ctxi;
121 list_for_each_entry(ctxi, &cfg->ctx_err_recovery, list)
122 if ((ctxi->ctxid == rctxid) || (ctxi->file == file))
129 * get_context() - obtains a validated and locked context reference
130 * @cfg: Internal structure associated with the host.
131 * @rctxid: Desired context (raw, un-decoded format).
132 * @arg: LUN information or file associated with request.
133 * @ctx_ctrl: Control information to 'steer' desired lookup.
135 * NOTE: despite the name pid, in linux, current->pid actually refers
136 * to the lightweight process id (tid) and can change if the process is
137 * multi threaded. The tgid remains constant for the process and only changes
138 * when the process of fork. For all intents and purposes, think of tgid
139 * as a pid in the traditional sense.
141 * Return: Validated context on success, NULL on failure
143 struct ctx_info *get_context(struct cxlflash_cfg *cfg, u64 rctxid,
144 void *arg, enum ctx_ctrl ctx_ctrl)
146 struct device *dev = &cfg->dev->dev;
147 struct ctx_info *ctxi = NULL;
148 struct lun_access *lun_access = NULL;
149 struct file *file = NULL;
150 struct llun_info *lli = arg;
151 u64 ctxid = DECODE_CTXID(rctxid);
153 pid_t pid = current->tgid, ctxpid = 0;
155 if (ctx_ctrl & CTX_CTRL_FILE) {
157 file = (struct file *)arg;
160 if (ctx_ctrl & CTX_CTRL_CLONE)
161 pid = current->parent->tgid;
163 if (likely(ctxid < MAX_CONTEXT)) {
165 mutex_lock(&cfg->ctx_tbl_list_mutex);
166 ctxi = cfg->ctx_tbl[ctxid];
168 if ((file && (ctxi->file != file)) ||
169 (!file && (ctxi->ctxid != rctxid)))
172 if ((ctx_ctrl & CTX_CTRL_ERR) ||
173 (!ctxi && (ctx_ctrl & CTX_CTRL_ERR_FALLBACK)))
174 ctxi = find_error_context(cfg, rctxid, file);
176 mutex_unlock(&cfg->ctx_tbl_list_mutex);
181 * Need to acquire ownership of the context while still
182 * under the table/list lock to serialize with a remove
183 * thread. Use the 'try' to avoid stalling the
184 * table/list lock for a single context.
186 * Note that the lock order is:
188 * cfg->ctx_tbl_list_mutex -> ctxi->mutex
190 * Therefore release ctx_tbl_list_mutex before retrying.
192 rc = mutex_trylock(&ctxi->mutex);
193 mutex_unlock(&cfg->ctx_tbl_list_mutex);
195 break; /* got the context's lock! */
202 if (likely(!(ctx_ctrl & CTX_CTRL_NOPID)))
207 list_for_each_entry(lun_access, &ctxi->luns, list)
208 if (lun_access->lli == lli)
215 dev_dbg(dev, "%s: rctxid=%016llx ctxinfo=%p ctxpid=%u pid=%u "
216 "ctx_ctrl=%u\n", __func__, rctxid, ctxi, ctxpid, pid,
222 mutex_unlock(&ctxi->mutex);
228 * put_context() - release a context that was retrieved from get_context()
229 * @ctxi: Context to release.
231 * For now, releasing the context equates to unlocking it's mutex.
233 void put_context(struct ctx_info *ctxi)
235 mutex_unlock(&ctxi->mutex);
239 * afu_attach() - attach a context to the AFU
240 * @cfg: Internal structure associated with the host.
241 * @ctxi: Context to attach.
243 * Upon setting the context capabilities, they must be confirmed with
244 * a read back operation as the context might have been closed since
245 * the mailbox was unlocked. When this occurs, registration is failed.
247 * Return: 0 on success, -errno on failure
249 static int afu_attach(struct cxlflash_cfg *cfg, struct ctx_info *ctxi)
251 struct device *dev = &cfg->dev->dev;
252 struct afu *afu = cfg->afu;
253 struct sisl_ctrl_map __iomem *ctrl_map = ctxi->ctrl_map;
257 /* Unlock cap and restrict user to read/write cmds in translated mode */
258 readq_be(&ctrl_map->mbox_r);
259 val = (SISL_CTX_CAP_READ_CMD | SISL_CTX_CAP_WRITE_CMD);
260 writeq_be(val, &ctrl_map->ctx_cap);
261 val = readq_be(&ctrl_map->ctx_cap);
262 if (val != (SISL_CTX_CAP_READ_CMD | SISL_CTX_CAP_WRITE_CMD)) {
263 dev_err(dev, "%s: ctx may be closed val=%016llx\n",
269 /* Set up MMIO registers pointing to the RHT */
270 writeq_be((u64)ctxi->rht_start, &ctrl_map->rht_start);
271 val = SISL_RHT_CNT_ID((u64)MAX_RHT_PER_CONTEXT, (u64)(afu->ctx_hndl));
272 writeq_be(val, &ctrl_map->rht_cnt_id);
274 dev_dbg(dev, "%s: returning rc=%d\n", __func__, rc);
279 * read_cap16() - issues a SCSI READ_CAP16 command
280 * @sdev: SCSI device associated with LUN.
281 * @lli: LUN destined for capacity request.
283 * The READ_CAP16 can take quite a while to complete. Should an EEH occur while
284 * in scsi_execute(), the EEH handler will attempt to recover. As part of the
285 * recovery, the handler drains all currently running ioctls, waiting until they
286 * have completed before proceeding with a reset. As this routine is used on the
287 * ioctl path, this can create a condition where the EEH handler becomes stuck,
288 * infinitely waiting for this ioctl thread. To avoid this behavior, temporarily
289 * unmark this thread as an ioctl thread by releasing the ioctl read semaphore.
290 * This will allow the EEH handler to proceed with a recovery while this thread
291 * is still running. Once the scsi_execute() returns, reacquire the ioctl read
292 * semaphore and check the adapter state in case it changed while inside of
293 * scsi_execute(). The state check will wait if the adapter is still being
294 * recovered or return a failure if the recovery failed. In the event that the
295 * adapter reset failed, simply return the failure as the ioctl would be unable
298 * Note that the above puts a requirement on this routine to only be called on
301 * Return: 0 on success, -errno on failure
303 static int read_cap16(struct scsi_device *sdev, struct llun_info *lli)
305 struct cxlflash_cfg *cfg = shost_priv(sdev->host);
306 struct device *dev = &cfg->dev->dev;
307 struct glun_info *gli = lli->parent;
310 u8 *sense_buf = NULL;
314 u32 to = CMD_TIMEOUT * HZ;
317 cmd_buf = kzalloc(CMD_BUFSIZE, GFP_KERNEL);
318 scsi_cmd = kzalloc(MAX_COMMAND_SIZE, GFP_KERNEL);
319 sense_buf = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_KERNEL);
320 if (unlikely(!cmd_buf || !scsi_cmd || !sense_buf)) {
325 scsi_cmd[0] = SERVICE_ACTION_IN_16; /* read cap(16) */
326 scsi_cmd[1] = SAI_READ_CAPACITY_16; /* service action */
327 put_unaligned_be32(CMD_BUFSIZE, &scsi_cmd[10]);
329 dev_dbg(dev, "%s: %ssending cmd(%02x)\n", __func__,
330 retry_cnt ? "re" : "", scsi_cmd[0]);
332 /* Drop the ioctl read semahpore across lengthy call */
333 up_read(&cfg->ioctl_rwsem);
334 result = scsi_execute(sdev, scsi_cmd, DMA_FROM_DEVICE, cmd_buf,
335 CMD_BUFSIZE, sense_buf, to, CMD_RETRIES, 0, NULL);
336 down_read(&cfg->ioctl_rwsem);
337 rc = check_state(cfg);
339 dev_err(dev, "%s: Failed state result=%08x\n",
345 if (driver_byte(result) == DRIVER_SENSE) {
346 result &= ~(0xFF<<24); /* DRIVER_SENSE is not an error */
347 if (result & SAM_STAT_CHECK_CONDITION) {
348 struct scsi_sense_hdr sshdr;
350 scsi_normalize_sense(sense_buf, SCSI_SENSE_BUFFERSIZE,
352 switch (sshdr.sense_key) {
354 case RECOVERED_ERROR:
357 result &= ~SAM_STAT_CHECK_CONDITION;
361 case 0x29: /* Power on Reset or Device Reset */
363 case 0x2A: /* Device capacity changed */
364 case 0x3F: /* Report LUNs changed */
365 /* Retry the command once more */
366 if (retry_cnt++ < 1) {
381 dev_err(dev, "%s: command failed, result=%08x\n",
388 * Read cap was successful, grab values from the buffer;
389 * note that we don't need to worry about unaligned access
390 * as the buffer is allocated on an aligned boundary.
392 mutex_lock(&gli->mutex);
393 gli->max_lba = be64_to_cpu(*((__be64 *)&cmd_buf[0]));
394 gli->blk_len = be32_to_cpu(*((__be32 *)&cmd_buf[8]));
395 mutex_unlock(&gli->mutex);
402 dev_dbg(dev, "%s: maxlba=%lld blklen=%d rc=%d\n",
403 __func__, gli->max_lba, gli->blk_len, rc);
408 * get_rhte() - obtains validated resource handle table entry reference
409 * @ctxi: Context owning the resource handle.
410 * @rhndl: Resource handle associated with entry.
411 * @lli: LUN associated with request.
413 * Return: Validated RHTE on success, NULL on failure
415 struct sisl_rht_entry *get_rhte(struct ctx_info *ctxi, res_hndl_t rhndl,
416 struct llun_info *lli)
418 struct cxlflash_cfg *cfg = ctxi->cfg;
419 struct device *dev = &cfg->dev->dev;
420 struct sisl_rht_entry *rhte = NULL;
422 if (unlikely(!ctxi->rht_start)) {
423 dev_dbg(dev, "%s: Context does not have allocated RHT\n",
428 if (unlikely(rhndl >= MAX_RHT_PER_CONTEXT)) {
429 dev_dbg(dev, "%s: Bad resource handle rhndl=%d\n",
434 if (unlikely(ctxi->rht_lun[rhndl] != lli)) {
435 dev_dbg(dev, "%s: Bad resource handle LUN rhndl=%d\n",
440 rhte = &ctxi->rht_start[rhndl];
441 if (unlikely(rhte->nmask == 0)) {
442 dev_dbg(dev, "%s: Unopened resource handle rhndl=%d\n",
453 * rhte_checkout() - obtains free/empty resource handle table entry
454 * @ctxi: Context owning the resource handle.
455 * @lli: LUN associated with request.
457 * Return: Free RHTE on success, NULL on failure
459 struct sisl_rht_entry *rhte_checkout(struct ctx_info *ctxi,
460 struct llun_info *lli)
462 struct cxlflash_cfg *cfg = ctxi->cfg;
463 struct device *dev = &cfg->dev->dev;
464 struct sisl_rht_entry *rhte = NULL;
467 /* Find a free RHT entry */
468 for (i = 0; i < MAX_RHT_PER_CONTEXT; i++)
469 if (ctxi->rht_start[i].nmask == 0) {
470 rhte = &ctxi->rht_start[i];
476 ctxi->rht_lun[i] = lli;
478 dev_dbg(dev, "%s: returning rhte=%p index=%d\n", __func__, rhte, i);
483 * rhte_checkin() - releases a resource handle table entry
484 * @ctxi: Context owning the resource handle.
485 * @rhte: RHTE to release.
487 void rhte_checkin(struct ctx_info *ctxi,
488 struct sisl_rht_entry *rhte)
490 u32 rsrc_handle = rhte - ctxi->rht_start;
495 ctxi->rht_lun[rsrc_handle] = NULL;
496 ctxi->rht_needs_ws[rsrc_handle] = false;
500 * rhte_format1() - populates a RHTE for format 1
501 * @rhte: RHTE to populate.
502 * @lun_id: LUN ID of LUN associated with RHTE.
503 * @perm: Desired permissions for RHTE.
504 * @port_sel: Port selection mask
506 static void rht_format1(struct sisl_rht_entry *rhte, u64 lun_id, u32 perm,
510 * Populate the Format 1 RHT entry for direct access (physical
511 * LUN) using the synchronization sequence defined in the
512 * SISLite specification.
514 struct sisl_rht_entry_f1 dummy = { 0 };
515 struct sisl_rht_entry_f1 *rhte_f1 = (struct sisl_rht_entry_f1 *)rhte;
517 memset(rhte_f1, 0, sizeof(*rhte_f1));
518 rhte_f1->fp = SISL_RHT_FP(1U, 0);
519 dma_wmb(); /* Make setting of format bit visible */
521 rhte_f1->lun_id = lun_id;
522 dma_wmb(); /* Make setting of LUN id visible */
525 * Use a dummy RHT Format 1 entry to build the second dword
526 * of the entry that must be populated in a single write when
527 * enabled (valid bit set to TRUE).
530 dummy.fp = SISL_RHT_FP(1U, perm);
531 dummy.port_sel = port_sel;
532 rhte_f1->dw = dummy.dw;
534 dma_wmb(); /* Make remaining RHT entry fields visible */
538 * cxlflash_lun_attach() - attaches a user to a LUN and manages the LUN's mode
539 * @gli: LUN to attach.
540 * @mode: Desired mode of the LUN.
541 * @locked: Mutex status on current thread.
543 * Return: 0 on success, -errno on failure
545 int cxlflash_lun_attach(struct glun_info *gli, enum lun_mode mode, bool locked)
550 mutex_lock(&gli->mutex);
552 if (gli->mode == MODE_NONE)
554 else if (gli->mode != mode) {
555 pr_debug("%s: gli_mode=%d requested_mode=%d\n",
556 __func__, gli->mode, mode);
562 WARN_ON(gli->users <= 0);
564 pr_debug("%s: Returning rc=%d gli->mode=%u gli->users=%u\n",
565 __func__, rc, gli->mode, gli->users);
567 mutex_unlock(&gli->mutex);
572 * cxlflash_lun_detach() - detaches a user from a LUN and resets the LUN's mode
573 * @gli: LUN to detach.
575 * When resetting the mode, terminate block allocation resources as they
576 * are no longer required (service is safe to call even when block allocation
577 * resources were not present - such as when transitioning from physical mode).
578 * These resources will be reallocated when needed (subsequent transition to
581 void cxlflash_lun_detach(struct glun_info *gli)
583 mutex_lock(&gli->mutex);
584 WARN_ON(gli->mode == MODE_NONE);
585 if (--gli->users == 0) {
586 gli->mode = MODE_NONE;
587 cxlflash_ba_terminate(&gli->blka.ba_lun);
589 pr_debug("%s: gli->users=%u\n", __func__, gli->users);
590 WARN_ON(gli->users < 0);
591 mutex_unlock(&gli->mutex);
595 * _cxlflash_disk_release() - releases the specified resource entry
596 * @sdev: SCSI device associated with LUN.
597 * @ctxi: Context owning resources.
598 * @release: Release ioctl data structure.
600 * For LUNs in virtual mode, the virtual LUN associated with the specified
601 * resource handle is resized to 0 prior to releasing the RHTE. Note that the
602 * AFU sync should _not_ be performed when the context is sitting on the error
603 * recovery list. A context on the error recovery list is not known to the AFU
604 * due to reset. When the context is recovered, it will be reattached and made
605 * known again to the AFU.
607 * Return: 0 on success, -errno on failure
609 int _cxlflash_disk_release(struct scsi_device *sdev,
610 struct ctx_info *ctxi,
611 struct dk_cxlflash_release *release)
613 struct cxlflash_cfg *cfg = shost_priv(sdev->host);
614 struct device *dev = &cfg->dev->dev;
615 struct llun_info *lli = sdev->hostdata;
616 struct glun_info *gli = lli->parent;
617 struct afu *afu = cfg->afu;
618 bool put_ctx = false;
620 struct dk_cxlflash_resize size;
621 res_hndl_t rhndl = release->rsrc_handle;
624 u64 ctxid = DECODE_CTXID(release->context_id),
625 rctxid = release->context_id;
627 struct sisl_rht_entry *rhte;
628 struct sisl_rht_entry_f1 *rhte_f1;
630 dev_dbg(dev, "%s: ctxid=%llu rhndl=%llu gli->mode=%u gli->users=%u\n",
631 __func__, ctxid, release->rsrc_handle, gli->mode, gli->users);
634 ctxi = get_context(cfg, rctxid, lli, CTX_CTRL_ERR_FALLBACK);
635 if (unlikely(!ctxi)) {
636 dev_dbg(dev, "%s: Bad context ctxid=%llu\n",
645 rhte = get_rhte(ctxi, rhndl, lli);
646 if (unlikely(!rhte)) {
647 dev_dbg(dev, "%s: Bad resource handle rhndl=%d\n",
654 * Resize to 0 for virtual LUNS by setting the size
655 * to 0. This will clear LXT_START and LXT_CNT fields
656 * in the RHT entry and properly sync with the AFU.
658 * Afterwards we clear the remaining fields.
662 marshal_rele_to_resize(release, &size);
664 rc = _cxlflash_vlun_resize(sdev, ctxi, &size);
666 dev_dbg(dev, "%s: resize failed rc %d\n", __func__, rc);
673 * Clear the Format 1 RHT entry for direct access
674 * (physical LUN) using the synchronization sequence
675 * defined in the SISLite specification.
677 rhte_f1 = (struct sisl_rht_entry_f1 *)rhte;
680 dma_wmb(); /* Make revocation of RHT entry visible */
683 dma_wmb(); /* Make clearing of LUN id visible */
686 dma_wmb(); /* Make RHT entry bottom-half clearing visible */
688 if (!ctxi->err_recovery_active)
689 cxlflash_afu_sync(afu, ctxid, rhndl, AFU_HW_SYNC);
692 WARN(1, "Unsupported LUN mode!");
696 rhte_checkin(ctxi, rhte);
697 cxlflash_lun_detach(gli);
702 dev_dbg(dev, "%s: returning rc=%d\n", __func__, rc);
706 int cxlflash_disk_release(struct scsi_device *sdev,
707 struct dk_cxlflash_release *release)
709 return _cxlflash_disk_release(sdev, NULL, release);
713 * destroy_context() - releases a context
714 * @cfg: Internal structure associated with the host.
715 * @ctxi: Context to release.
717 * This routine is safe to be called with a a non-initialized context.
718 * Also note that the routine conditionally checks for the existence
719 * of the context control map before clearing the RHT registers and
720 * context capabilities because it is possible to destroy a context
721 * while the context is in the error state (previous mapping was
722 * removed [so there is no need to worry about clearing] and context
723 * is waiting for a new mapping).
725 static void destroy_context(struct cxlflash_cfg *cfg,
726 struct ctx_info *ctxi)
728 struct afu *afu = cfg->afu;
730 if (ctxi->initialized) {
731 WARN_ON(!list_empty(&ctxi->luns));
733 /* Clear RHT registers and drop all capabilities for context */
734 if (afu->afu_map && ctxi->ctrl_map) {
735 writeq_be(0, &ctxi->ctrl_map->rht_start);
736 writeq_be(0, &ctxi->ctrl_map->rht_cnt_id);
737 writeq_be(0, &ctxi->ctrl_map->ctx_cap);
741 /* Free memory associated with context */
742 free_page((ulong)ctxi->rht_start);
743 kfree(ctxi->rht_needs_ws);
744 kfree(ctxi->rht_lun);
749 * create_context() - allocates and initializes a context
750 * @cfg: Internal structure associated with the host.
752 * Return: Allocated context on success, NULL on failure
754 static struct ctx_info *create_context(struct cxlflash_cfg *cfg)
756 struct device *dev = &cfg->dev->dev;
757 struct ctx_info *ctxi = NULL;
758 struct llun_info **lli = NULL;
760 struct sisl_rht_entry *rhte;
762 ctxi = kzalloc(sizeof(*ctxi), GFP_KERNEL);
763 lli = kzalloc((MAX_RHT_PER_CONTEXT * sizeof(*lli)), GFP_KERNEL);
764 ws = kzalloc((MAX_RHT_PER_CONTEXT * sizeof(*ws)), GFP_KERNEL);
765 if (unlikely(!ctxi || !lli || !ws)) {
766 dev_err(dev, "%s: Unable to allocate context\n", __func__);
770 rhte = (struct sisl_rht_entry *)get_zeroed_page(GFP_KERNEL);
771 if (unlikely(!rhte)) {
772 dev_err(dev, "%s: Unable to allocate RHT\n", __func__);
777 ctxi->rht_needs_ws = ws;
778 ctxi->rht_start = rhte;
791 * init_context() - initializes a previously allocated context
792 * @ctxi: Previously allocated context
793 * @cfg: Internal structure associated with the host.
794 * @ctx: Previously obtained CXL context reference.
795 * @ctxid: Previously obtained process element associated with CXL context.
796 * @file: Previously obtained file associated with CXL context.
797 * @perms: User-specified permissions.
799 static void init_context(struct ctx_info *ctxi, struct cxlflash_cfg *cfg,
800 struct cxl_context *ctx, int ctxid, struct file *file,
803 struct afu *afu = cfg->afu;
805 ctxi->rht_perms = perms;
806 ctxi->ctrl_map = &afu->afu_map->ctrls[ctxid].ctrl;
807 ctxi->ctxid = ENCODE_CTXID(ctxi, ctxid);
808 ctxi->pid = current->tgid; /* tgid = pid */
812 ctxi->initialized = true;
813 mutex_init(&ctxi->mutex);
814 kref_init(&ctxi->kref);
815 INIT_LIST_HEAD(&ctxi->luns);
816 INIT_LIST_HEAD(&ctxi->list); /* initialize for list_empty() */
820 * remove_context() - context kref release handler
821 * @kref: Kernel reference associated with context to be removed.
823 * When a context no longer has any references it can safely be removed
824 * from global access and destroyed. Note that it is assumed the thread
825 * relinquishing access to the context holds its mutex.
827 static void remove_context(struct kref *kref)
829 struct ctx_info *ctxi = container_of(kref, struct ctx_info, kref);
830 struct cxlflash_cfg *cfg = ctxi->cfg;
831 u64 ctxid = DECODE_CTXID(ctxi->ctxid);
833 /* Remove context from table/error list */
834 WARN_ON(!mutex_is_locked(&ctxi->mutex));
835 ctxi->unavail = true;
836 mutex_unlock(&ctxi->mutex);
837 mutex_lock(&cfg->ctx_tbl_list_mutex);
838 mutex_lock(&ctxi->mutex);
840 if (!list_empty(&ctxi->list))
841 list_del(&ctxi->list);
842 cfg->ctx_tbl[ctxid] = NULL;
843 mutex_unlock(&cfg->ctx_tbl_list_mutex);
844 mutex_unlock(&ctxi->mutex);
846 /* Context now completely uncoupled/unreachable */
847 destroy_context(cfg, ctxi);
851 * _cxlflash_disk_detach() - detaches a LUN from a context
852 * @sdev: SCSI device associated with LUN.
853 * @ctxi: Context owning resources.
854 * @detach: Detach ioctl data structure.
856 * As part of the detach, all per-context resources associated with the LUN
857 * are cleaned up. When detaching the last LUN for a context, the context
858 * itself is cleaned up and released.
860 * Return: 0 on success, -errno on failure
862 static int _cxlflash_disk_detach(struct scsi_device *sdev,
863 struct ctx_info *ctxi,
864 struct dk_cxlflash_detach *detach)
866 struct cxlflash_cfg *cfg = shost_priv(sdev->host);
867 struct device *dev = &cfg->dev->dev;
868 struct llun_info *lli = sdev->hostdata;
869 struct lun_access *lun_access, *t;
870 struct dk_cxlflash_release rel;
871 bool put_ctx = false;
875 u64 ctxid = DECODE_CTXID(detach->context_id),
876 rctxid = detach->context_id;
878 dev_dbg(dev, "%s: ctxid=%llu\n", __func__, ctxid);
881 ctxi = get_context(cfg, rctxid, lli, CTX_CTRL_ERR_FALLBACK);
882 if (unlikely(!ctxi)) {
883 dev_dbg(dev, "%s: Bad context ctxid=%llu\n",
892 /* Cleanup outstanding resources tied to this LUN */
894 marshal_det_to_rele(detach, &rel);
895 for (i = 0; i < MAX_RHT_PER_CONTEXT; i++) {
896 if (ctxi->rht_lun[i] == lli) {
898 _cxlflash_disk_release(sdev, ctxi, &rel);
901 /* No need to loop further if we're done */
902 if (ctxi->rht_out == 0)
907 /* Take our LUN out of context, free the node */
908 list_for_each_entry_safe(lun_access, t, &ctxi->luns, list)
909 if (lun_access->lli == lli) {
910 list_del(&lun_access->list);
917 * Release the context reference and the sdev reference that
918 * bound this LUN to the context.
920 if (kref_put(&ctxi->kref, remove_context))
922 scsi_device_put(sdev);
926 dev_dbg(dev, "%s: returning rc=%d\n", __func__, rc);
930 static int cxlflash_disk_detach(struct scsi_device *sdev,
931 struct dk_cxlflash_detach *detach)
933 return _cxlflash_disk_detach(sdev, NULL, detach);
937 * cxlflash_cxl_release() - release handler for adapter file descriptor
938 * @inode: File-system inode associated with fd.
939 * @file: File installed with adapter file descriptor.
941 * This routine is the release handler for the fops registered with
942 * the CXL services on an initial attach for a context. It is called
943 * when a close (explicity by the user or as part of a process tear
944 * down) is performed on the adapter file descriptor returned to the
945 * user. The user should be aware that explicitly performing a close
946 * considered catastrophic and subsequent usage of the superpipe API
947 * with previously saved off tokens will fail.
949 * This routine derives the context reference and calls detach for
950 * each LUN associated with the context.The final detach operation
951 * causes the context itself to be freed. With exception to when the
952 * CXL process element (context id) lookup fails (a case that should
953 * theoretically never occur), every call into this routine results
954 * in a complete freeing of a context.
956 * Return: 0 on success
958 static int cxlflash_cxl_release(struct inode *inode, struct file *file)
960 struct cxl_context *ctx = cxl_fops_get_context(file);
961 struct cxlflash_cfg *cfg = container_of(file->f_op, struct cxlflash_cfg,
963 struct device *dev = &cfg->dev->dev;
964 struct ctx_info *ctxi = NULL;
965 struct dk_cxlflash_detach detach = { { 0 }, 0 };
966 struct lun_access *lun_access, *t;
967 enum ctx_ctrl ctrl = CTX_CTRL_ERR_FALLBACK | CTX_CTRL_FILE;
970 ctxid = cxl_process_element(ctx);
971 if (unlikely(ctxid < 0)) {
972 dev_err(dev, "%s: Context %p was closed ctxid=%d\n",
973 __func__, ctx, ctxid);
977 ctxi = get_context(cfg, ctxid, file, ctrl);
978 if (unlikely(!ctxi)) {
979 ctxi = get_context(cfg, ctxid, file, ctrl | CTX_CTRL_CLONE);
981 dev_dbg(dev, "%s: ctxid=%d already free\n",
986 dev_dbg(dev, "%s: Another process owns ctxid=%d\n",
992 dev_dbg(dev, "%s: close for ctxid=%d\n", __func__, ctxid);
994 detach.context_id = ctxi->ctxid;
995 list_for_each_entry_safe(lun_access, t, &ctxi->luns, list)
996 _cxlflash_disk_detach(lun_access->sdev, ctxi, &detach);
998 cxl_fd_release(inode, file);
1000 dev_dbg(dev, "%s: returning\n", __func__);
1005 * unmap_context() - clears a previously established mapping
1006 * @ctxi: Context owning the mapping.
1008 * This routine is used to switch between the error notification page
1009 * (dummy page of all 1's) and the real mapping (established by the CXL
1012 static void unmap_context(struct ctx_info *ctxi)
1014 unmap_mapping_range(ctxi->file->f_mapping, 0, 0, 1);
1018 * get_err_page() - obtains and allocates the error notification page
1019 * @cfg: Internal structure associated with the host.
1021 * Return: error notification page on success, NULL on failure
1023 static struct page *get_err_page(struct cxlflash_cfg *cfg)
1025 struct page *err_page = global.err_page;
1026 struct device *dev = &cfg->dev->dev;
1028 if (unlikely(!err_page)) {
1029 err_page = alloc_page(GFP_KERNEL);
1030 if (unlikely(!err_page)) {
1031 dev_err(dev, "%s: Unable to allocate err_page\n",
1036 memset(page_address(err_page), -1, PAGE_SIZE);
1038 /* Serialize update w/ other threads to avoid a leak */
1039 mutex_lock(&global.mutex);
1040 if (likely(!global.err_page))
1041 global.err_page = err_page;
1043 __free_page(err_page);
1044 err_page = global.err_page;
1046 mutex_unlock(&global.mutex);
1050 dev_dbg(dev, "%s: returning err_page=%p\n", __func__, err_page);
1055 * cxlflash_mmap_fault() - mmap fault handler for adapter file descriptor
1056 * @vmf: VM fault associated with current fault.
1058 * To support error notification via MMIO, faults are 'caught' by this routine
1059 * that was inserted before passing back the adapter file descriptor on attach.
1060 * When a fault occurs, this routine evaluates if error recovery is active and
1061 * if so, installs the error page to 'notify' the user about the error state.
1062 * During normal operation, the fault is simply handled by the original fault
1063 * handler that was installed by CXL services as part of initializing the
1064 * adapter file descriptor. The VMA's page protection bits are toggled to
1065 * indicate cached/not-cached depending on the memory backing the fault.
1067 * Return: 0 on success, VM_FAULT_SIGBUS on failure
1069 static int cxlflash_mmap_fault(struct vm_fault *vmf)
1071 struct vm_area_struct *vma = vmf->vma;
1072 struct file *file = vma->vm_file;
1073 struct cxl_context *ctx = cxl_fops_get_context(file);
1074 struct cxlflash_cfg *cfg = container_of(file->f_op, struct cxlflash_cfg,
1076 struct device *dev = &cfg->dev->dev;
1077 struct ctx_info *ctxi = NULL;
1078 struct page *err_page = NULL;
1079 enum ctx_ctrl ctrl = CTX_CTRL_ERR_FALLBACK | CTX_CTRL_FILE;
1083 ctxid = cxl_process_element(ctx);
1084 if (unlikely(ctxid < 0)) {
1085 dev_err(dev, "%s: Context %p was closed ctxid=%d\n",
1086 __func__, ctx, ctxid);
1090 ctxi = get_context(cfg, ctxid, file, ctrl);
1091 if (unlikely(!ctxi)) {
1092 dev_dbg(dev, "%s: Bad context ctxid=%d\n", __func__, ctxid);
1096 dev_dbg(dev, "%s: fault for context %d\n", __func__, ctxid);
1098 if (likely(!ctxi->err_recovery_active)) {
1099 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1100 rc = ctxi->cxl_mmap_vmops->fault(vmf);
1102 dev_dbg(dev, "%s: err recovery active, use err_page\n",
1105 err_page = get_err_page(cfg);
1106 if (unlikely(!err_page)) {
1107 dev_err(dev, "%s: Could not get err_page\n", __func__);
1108 rc = VM_FAULT_RETRY;
1113 vmf->page = err_page;
1114 vma->vm_page_prot = pgprot_cached(vma->vm_page_prot);
1120 dev_dbg(dev, "%s: returning rc=%d\n", __func__, rc);
1124 rc = VM_FAULT_SIGBUS;
1129 * Local MMAP vmops to 'catch' faults
1131 static const struct vm_operations_struct cxlflash_mmap_vmops = {
1132 .fault = cxlflash_mmap_fault,
1136 * cxlflash_cxl_mmap() - mmap handler for adapter file descriptor
1137 * @file: File installed with adapter file descriptor.
1138 * @vma: VM area associated with mapping.
1140 * Installs local mmap vmops to 'catch' faults for error notification support.
1142 * Return: 0 on success, -errno on failure
1144 static int cxlflash_cxl_mmap(struct file *file, struct vm_area_struct *vma)
1146 struct cxl_context *ctx = cxl_fops_get_context(file);
1147 struct cxlflash_cfg *cfg = container_of(file->f_op, struct cxlflash_cfg,
1149 struct device *dev = &cfg->dev->dev;
1150 struct ctx_info *ctxi = NULL;
1151 enum ctx_ctrl ctrl = CTX_CTRL_ERR_FALLBACK | CTX_CTRL_FILE;
1155 ctxid = cxl_process_element(ctx);
1156 if (unlikely(ctxid < 0)) {
1157 dev_err(dev, "%s: Context %p was closed ctxid=%d\n",
1158 __func__, ctx, ctxid);
1163 ctxi = get_context(cfg, ctxid, file, ctrl);
1164 if (unlikely(!ctxi)) {
1165 dev_dbg(dev, "%s: Bad context ctxid=%d\n", __func__, ctxid);
1170 dev_dbg(dev, "%s: mmap for context %d\n", __func__, ctxid);
1172 rc = cxl_fd_mmap(file, vma);
1174 /* Insert ourself in the mmap fault handler path */
1175 ctxi->cxl_mmap_vmops = vma->vm_ops;
1176 vma->vm_ops = &cxlflash_mmap_vmops;
1185 const struct file_operations cxlflash_cxl_fops = {
1186 .owner = THIS_MODULE,
1187 .mmap = cxlflash_cxl_mmap,
1188 .release = cxlflash_cxl_release,
1192 * cxlflash_mark_contexts_error() - move contexts to error state and list
1193 * @cfg: Internal structure associated with the host.
1195 * A context is only moved over to the error list when there are no outstanding
1196 * references to it. This ensures that a running operation has completed.
1198 * Return: 0 on success, -errno on failure
1200 int cxlflash_mark_contexts_error(struct cxlflash_cfg *cfg)
1203 struct ctx_info *ctxi = NULL;
1205 mutex_lock(&cfg->ctx_tbl_list_mutex);
1207 for (i = 0; i < MAX_CONTEXT; i++) {
1208 ctxi = cfg->ctx_tbl[i];
1210 mutex_lock(&ctxi->mutex);
1211 cfg->ctx_tbl[i] = NULL;
1212 list_add(&ctxi->list, &cfg->ctx_err_recovery);
1213 ctxi->err_recovery_active = true;
1214 ctxi->ctrl_map = NULL;
1215 unmap_context(ctxi);
1216 mutex_unlock(&ctxi->mutex);
1220 mutex_unlock(&cfg->ctx_tbl_list_mutex);
1227 static const struct file_operations null_fops = {
1228 .owner = THIS_MODULE,
1232 * check_state() - checks and responds to the current adapter state
1233 * @cfg: Internal structure associated with the host.
1235 * This routine can block and should only be used on process context.
1236 * It assumes that the caller is an ioctl thread and holding the ioctl
1237 * read semaphore. This is temporarily let up across the wait to allow
1238 * for draining actively running ioctls. Also note that when waking up
1239 * from waiting in reset, the state is unknown and must be checked again
1240 * before proceeding.
1242 * Return: 0 on success, -errno on failure
1244 int check_state(struct cxlflash_cfg *cfg)
1246 struct device *dev = &cfg->dev->dev;
1250 switch (cfg->state) {
1252 dev_dbg(dev, "%s: Reset state, going to wait...\n", __func__);
1253 up_read(&cfg->ioctl_rwsem);
1254 rc = wait_event_interruptible(cfg->reset_waitq,
1255 cfg->state != STATE_RESET);
1256 down_read(&cfg->ioctl_rwsem);
1260 case STATE_FAILTERM:
1261 dev_dbg(dev, "%s: Failed/Terminating\n", __func__);
1272 * cxlflash_disk_attach() - attach a LUN to a context
1273 * @sdev: SCSI device associated with LUN.
1274 * @attach: Attach ioctl data structure.
1276 * Creates a context and attaches LUN to it. A LUN can only be attached
1277 * one time to a context (subsequent attaches for the same context/LUN pair
1278 * are not supported). Additional LUNs can be attached to a context by
1279 * specifying the 'reuse' flag defined in the cxlflash_ioctl.h header.
1281 * Return: 0 on success, -errno on failure
1283 static int cxlflash_disk_attach(struct scsi_device *sdev,
1284 struct dk_cxlflash_attach *attach)
1286 struct cxlflash_cfg *cfg = shost_priv(sdev->host);
1287 struct device *dev = &cfg->dev->dev;
1288 struct afu *afu = cfg->afu;
1289 struct llun_info *lli = sdev->hostdata;
1290 struct glun_info *gli = lli->parent;
1291 struct cxl_ioctl_start_work *work;
1292 struct ctx_info *ctxi = NULL;
1293 struct lun_access *lun_access = NULL;
1299 struct file *file = NULL;
1301 struct cxl_context *ctx = NULL;
1305 if (attach->num_interrupts > 4) {
1306 dev_dbg(dev, "%s: Cannot support this many interrupts %llu\n",
1307 __func__, attach->num_interrupts);
1312 if (gli->max_lba == 0) {
1313 dev_dbg(dev, "%s: No capacity info for LUN=%016llx\n",
1314 __func__, lli->lun_id[sdev->channel]);
1315 rc = read_cap16(sdev, lli);
1317 dev_err(dev, "%s: Invalid device rc=%d\n",
1322 dev_dbg(dev, "%s: LBA = %016llx\n", __func__, gli->max_lba);
1323 dev_dbg(dev, "%s: BLK_LEN = %08x\n", __func__, gli->blk_len);
1326 if (attach->hdr.flags & DK_CXLFLASH_ATTACH_REUSE_CONTEXT) {
1327 rctxid = attach->context_id;
1328 ctxi = get_context(cfg, rctxid, NULL, 0);
1330 dev_dbg(dev, "%s: Bad context rctxid=%016llx\n",
1336 list_for_each_entry(lun_access, &ctxi->luns, list)
1337 if (lun_access->lli == lli) {
1338 dev_dbg(dev, "%s: Already attached\n",
1345 rc = scsi_device_get(sdev);
1347 dev_err(dev, "%s: Unable to get sdev reference\n", __func__);
1351 lun_access = kzalloc(sizeof(*lun_access), GFP_KERNEL);
1352 if (unlikely(!lun_access)) {
1353 dev_err(dev, "%s: Unable to allocate lun_access\n", __func__);
1358 lun_access->lli = lli;
1359 lun_access->sdev = sdev;
1361 /* Non-NULL context indicates reuse (another context reference) */
1363 dev_dbg(dev, "%s: Reusing context for LUN rctxid=%016llx\n",
1365 kref_get(&ctxi->kref);
1366 list_add(&lun_access->list, &ctxi->luns);
1370 ctxi = create_context(cfg);
1371 if (unlikely(!ctxi)) {
1372 dev_err(dev, "%s: Failed to create context ctxid=%d\n",
1377 ctx = cxl_dev_context_init(cfg->dev);
1378 if (IS_ERR_OR_NULL(ctx)) {
1379 dev_err(dev, "%s: Could not initialize context %p\n",
1386 work->num_interrupts = attach->num_interrupts;
1387 work->flags = CXL_START_WORK_NUM_IRQS;
1389 rc = cxl_start_work(ctx, work);
1391 dev_dbg(dev, "%s: Could not start context rc=%d\n",
1396 ctxid = cxl_process_element(ctx);
1397 if (unlikely((ctxid >= MAX_CONTEXT) || (ctxid < 0))) {
1398 dev_err(dev, "%s: ctxid=%d invalid\n", __func__, ctxid);
1403 file = cxl_get_fd(ctx, &cfg->cxl_fops, &fd);
1404 if (unlikely(fd < 0)) {
1406 dev_err(dev, "%s: Could not get file descriptor\n", __func__);
1410 /* Translate read/write O_* flags from fcntl.h to AFU permission bits */
1411 perms = SISL_RHT_PERM(attach->hdr.flags + 1);
1413 /* Context mutex is locked upon return */
1414 init_context(ctxi, cfg, ctx, ctxid, file, perms);
1416 rc = afu_attach(cfg, ctxi);
1418 dev_err(dev, "%s: Could not attach AFU rc %d\n", __func__, rc);
1423 * No error paths after this point. Once the fd is installed it's
1424 * visible to user space and can't be undone safely on this thread.
1425 * There is no need to worry about a deadlock here because no one
1426 * knows about us yet; we can be the only one holding our mutex.
1428 list_add(&lun_access->list, &ctxi->luns);
1429 mutex_lock(&cfg->ctx_tbl_list_mutex);
1430 mutex_lock(&ctxi->mutex);
1431 cfg->ctx_tbl[ctxid] = ctxi;
1432 mutex_unlock(&cfg->ctx_tbl_list_mutex);
1433 fd_install(fd, file);
1437 flags |= DK_CXLFLASH_APP_CLOSE_ADAP_FD;
1438 if (afu_is_sq_cmd_mode(afu))
1439 flags |= DK_CXLFLASH_CONTEXT_SQ_CMD_MODE;
1441 attach->hdr.return_flags = flags;
1442 attach->context_id = ctxi->ctxid;
1443 attach->block_size = gli->blk_len;
1444 attach->mmio_size = sizeof(afu->afu_map->hosts[0].harea);
1445 attach->last_lba = gli->max_lba;
1446 attach->max_xfer = sdev->host->max_sectors * MAX_SECTOR_UNIT;
1447 attach->max_xfer /= gli->blk_len;
1450 attach->adap_fd = fd;
1455 dev_dbg(dev, "%s: returning ctxid=%d fd=%d bs=%lld rc=%d llba=%lld\n",
1456 __func__, ctxid, fd, attach->block_size, rc, attach->last_lba);
1460 /* Cleanup CXL context; okay to 'stop' even if it was not started */
1461 if (!IS_ERR_OR_NULL(ctx)) {
1462 cxl_stop_context(ctx);
1463 cxl_release_context(ctx);
1468 * Here, we're overriding the fops with a dummy all-NULL fops because
1469 * fput() calls the release fop, which will cause us to mistakenly
1470 * call into the CXL code. Rather than try to add yet more complexity
1471 * to that routine (cxlflash_cxl_release) we should try to fix the
1475 file->f_op = &null_fops;
1482 /* Cleanup our context */
1484 destroy_context(cfg, ctxi);
1489 scsi_device_put(sdev);
1494 * recover_context() - recovers a context in error
1495 * @cfg: Internal structure associated with the host.
1496 * @ctxi: Context to release.
1497 * @adap_fd: Adapter file descriptor associated with new/recovered context.
1499 * Restablishes the state for a context-in-error.
1501 * Return: 0 on success, -errno on failure
1503 static int recover_context(struct cxlflash_cfg *cfg,
1504 struct ctx_info *ctxi,
1507 struct device *dev = &cfg->dev->dev;
1512 struct cxl_context *ctx;
1513 struct afu *afu = cfg->afu;
1515 ctx = cxl_dev_context_init(cfg->dev);
1516 if (IS_ERR_OR_NULL(ctx)) {
1517 dev_err(dev, "%s: Could not initialize context %p\n",
1523 rc = cxl_start_work(ctx, &ctxi->work);
1525 dev_dbg(dev, "%s: Could not start context rc=%d\n",
1530 ctxid = cxl_process_element(ctx);
1531 if (unlikely((ctxid >= MAX_CONTEXT) || (ctxid < 0))) {
1532 dev_err(dev, "%s: ctxid=%d invalid\n", __func__, ctxid);
1537 file = cxl_get_fd(ctx, &cfg->cxl_fops, &fd);
1538 if (unlikely(fd < 0)) {
1540 dev_err(dev, "%s: Could not get file descriptor\n", __func__);
1544 /* Update with new MMIO area based on updated context id */
1545 ctxi->ctrl_map = &afu->afu_map->ctrls[ctxid].ctrl;
1547 rc = afu_attach(cfg, ctxi);
1549 dev_err(dev, "%s: Could not attach AFU rc %d\n", __func__, rc);
1554 * No error paths after this point. Once the fd is installed it's
1555 * visible to user space and can't be undone safely on this thread.
1557 ctxi->ctxid = ENCODE_CTXID(ctxi, ctxid);
1562 * Put context back in table (note the reinit of the context list);
1563 * we must first drop the context's mutex and then acquire it in
1564 * order with the table/list mutex to avoid a deadlock - safe to do
1565 * here because no one can find us at this moment in time.
1567 mutex_unlock(&ctxi->mutex);
1568 mutex_lock(&cfg->ctx_tbl_list_mutex);
1569 mutex_lock(&ctxi->mutex);
1570 list_del_init(&ctxi->list);
1571 cfg->ctx_tbl[ctxid] = ctxi;
1572 mutex_unlock(&cfg->ctx_tbl_list_mutex);
1573 fd_install(fd, file);
1576 dev_dbg(dev, "%s: returning ctxid=%d fd=%d rc=%d\n",
1577 __func__, ctxid, fd, rc);
1584 cxl_stop_context(ctx);
1586 cxl_release_context(ctx);
1591 * cxlflash_afu_recover() - initiates AFU recovery
1592 * @sdev: SCSI device associated with LUN.
1593 * @recover: Recover ioctl data structure.
1595 * Only a single recovery is allowed at a time to avoid exhausting CXL
1596 * resources (leading to recovery failure) in the event that we're up
1597 * against the maximum number of contexts limit. For similar reasons,
1598 * a context recovery is retried if there are multiple recoveries taking
1599 * place at the same time and the failure was due to CXL services being
1600 * unable to keep up.
1602 * As this routine is called on ioctl context, it holds the ioctl r/w
1603 * semaphore that is used to drain ioctls in recovery scenarios. The
1604 * implementation to achieve the pacing described above (a local mutex)
1605 * requires that the ioctl r/w semaphore be dropped and reacquired to
1606 * avoid a 3-way deadlock when multiple process recoveries operate in
1609 * Because a user can detect an error condition before the kernel, it is
1610 * quite possible for this routine to act as the kernel's EEH detection
1611 * source (MMIO read of mbox_r). Because of this, there is a window of
1612 * time where an EEH might have been detected but not yet 'serviced'
1613 * (callback invoked, causing the device to enter reset state). To avoid
1614 * looping in this routine during that window, a 1 second sleep is in place
1615 * between the time the MMIO failure is detected and the time a wait on the
1616 * reset wait queue is attempted via check_state().
1618 * Return: 0 on success, -errno on failure
1620 static int cxlflash_afu_recover(struct scsi_device *sdev,
1621 struct dk_cxlflash_recover_afu *recover)
1623 struct cxlflash_cfg *cfg = shost_priv(sdev->host);
1624 struct device *dev = &cfg->dev->dev;
1625 struct llun_info *lli = sdev->hostdata;
1626 struct afu *afu = cfg->afu;
1627 struct ctx_info *ctxi = NULL;
1628 struct mutex *mutex = &cfg->ctx_recovery_mutex;
1630 u64 ctxid = DECODE_CTXID(recover->context_id),
1631 rctxid = recover->context_id;
1633 int lretry = 20; /* up to 2 seconds */
1634 int new_adap_fd = -1;
1637 atomic_inc(&cfg->recovery_threads);
1638 up_read(&cfg->ioctl_rwsem);
1639 rc = mutex_lock_interruptible(mutex);
1640 down_read(&cfg->ioctl_rwsem);
1643 rc = check_state(cfg);
1645 dev_err(dev, "%s: Failed state rc=%d\n", __func__, rc);
1650 dev_dbg(dev, "%s: reason=%016llx rctxid=%016llx\n",
1651 __func__, recover->reason, rctxid);
1654 /* Ensure that this process is attached to the context */
1655 ctxi = get_context(cfg, rctxid, lli, CTX_CTRL_ERR_FALLBACK);
1656 if (unlikely(!ctxi)) {
1657 dev_dbg(dev, "%s: Bad context ctxid=%llu\n", __func__, ctxid);
1662 if (ctxi->err_recovery_active) {
1664 rc = recover_context(cfg, ctxi, &new_adap_fd);
1666 dev_err(dev, "%s: Recovery failed ctxid=%llu rc=%d\n",
1667 __func__, ctxid, rc);
1668 if ((rc == -ENODEV) &&
1669 ((atomic_read(&cfg->recovery_threads) > 1) ||
1671 dev_dbg(dev, "%s: Going to try again\n",
1673 mutex_unlock(mutex);
1675 rc = mutex_lock_interruptible(mutex);
1684 ctxi->err_recovery_active = false;
1686 flags = DK_CXLFLASH_APP_CLOSE_ADAP_FD |
1687 DK_CXLFLASH_RECOVER_AFU_CONTEXT_RESET;
1688 if (afu_is_sq_cmd_mode(afu))
1689 flags |= DK_CXLFLASH_CONTEXT_SQ_CMD_MODE;
1691 recover->hdr.return_flags = flags;
1692 recover->context_id = ctxi->ctxid;
1693 recover->adap_fd = new_adap_fd;
1694 recover->mmio_size = sizeof(afu->afu_map->hosts[0].harea);
1698 /* Test if in error state */
1699 reg = readq_be(&afu->ctrl_map->mbox_r);
1701 dev_dbg(dev, "%s: MMIO fail, wait for recovery.\n", __func__);
1704 * Before checking the state, put back the context obtained with
1705 * get_context() as it is no longer needed and sleep for a short
1706 * period of time (see prolog notes).
1711 rc = check_state(cfg);
1717 dev_dbg(dev, "%s: MMIO working, no recovery required\n", __func__);
1721 mutex_unlock(mutex);
1722 atomic_dec_if_positive(&cfg->recovery_threads);
1727 * process_sense() - evaluates and processes sense data
1728 * @sdev: SCSI device associated with LUN.
1729 * @verify: Verify ioctl data structure.
1731 * Return: 0 on success, -errno on failure
1733 static int process_sense(struct scsi_device *sdev,
1734 struct dk_cxlflash_verify *verify)
1736 struct cxlflash_cfg *cfg = shost_priv(sdev->host);
1737 struct device *dev = &cfg->dev->dev;
1738 struct llun_info *lli = sdev->hostdata;
1739 struct glun_info *gli = lli->parent;
1740 u64 prev_lba = gli->max_lba;
1741 struct scsi_sense_hdr sshdr = { 0 };
1744 rc = scsi_normalize_sense((const u8 *)&verify->sense_data,
1745 DK_CXLFLASH_VERIFY_SENSE_LEN, &sshdr);
1747 dev_err(dev, "%s: Failed to normalize sense data\n", __func__);
1752 switch (sshdr.sense_key) {
1754 case RECOVERED_ERROR:
1758 case UNIT_ATTENTION:
1759 switch (sshdr.asc) {
1760 case 0x29: /* Power on Reset or Device Reset */
1762 case 0x2A: /* Device settings/capacity changed */
1763 rc = read_cap16(sdev, lli);
1768 if (prev_lba != gli->max_lba)
1769 dev_dbg(dev, "%s: Capacity changed old=%lld "
1770 "new=%lld\n", __func__, prev_lba,
1773 case 0x3F: /* Report LUNs changed, Rescan. */
1774 scsi_scan_host(cfg->host);
1786 dev_dbg(dev, "%s: sense_key %x asc %x ascq %x rc %d\n", __func__,
1787 sshdr.sense_key, sshdr.asc, sshdr.ascq, rc);
1792 * cxlflash_disk_verify() - verifies a LUN is the same and handle size changes
1793 * @sdev: SCSI device associated with LUN.
1794 * @verify: Verify ioctl data structure.
1796 * Return: 0 on success, -errno on failure
1798 static int cxlflash_disk_verify(struct scsi_device *sdev,
1799 struct dk_cxlflash_verify *verify)
1802 struct ctx_info *ctxi = NULL;
1803 struct cxlflash_cfg *cfg = shost_priv(sdev->host);
1804 struct device *dev = &cfg->dev->dev;
1805 struct llun_info *lli = sdev->hostdata;
1806 struct glun_info *gli = lli->parent;
1807 struct sisl_rht_entry *rhte = NULL;
1808 res_hndl_t rhndl = verify->rsrc_handle;
1809 u64 ctxid = DECODE_CTXID(verify->context_id),
1810 rctxid = verify->context_id;
1813 dev_dbg(dev, "%s: ctxid=%llu rhndl=%016llx, hint=%016llx, "
1814 "flags=%016llx\n", __func__, ctxid, verify->rsrc_handle,
1815 verify->hint, verify->hdr.flags);
1817 ctxi = get_context(cfg, rctxid, lli, 0);
1818 if (unlikely(!ctxi)) {
1819 dev_dbg(dev, "%s: Bad context ctxid=%llu\n", __func__, ctxid);
1824 rhte = get_rhte(ctxi, rhndl, lli);
1825 if (unlikely(!rhte)) {
1826 dev_dbg(dev, "%s: Bad resource handle rhndl=%d\n",
1833 * Look at the hint/sense to see if it requires us to redrive
1834 * inquiry (i.e. the Unit attention is due to the WWN changing).
1836 if (verify->hint & DK_CXLFLASH_VERIFY_HINT_SENSE) {
1837 /* Can't hold mutex across process_sense/read_cap16,
1838 * since we could have an intervening EEH event.
1840 ctxi->unavail = true;
1841 mutex_unlock(&ctxi->mutex);
1842 rc = process_sense(sdev, verify);
1844 dev_err(dev, "%s: Failed to validate sense data (%d)\n",
1846 mutex_lock(&ctxi->mutex);
1847 ctxi->unavail = false;
1850 mutex_lock(&ctxi->mutex);
1851 ctxi->unavail = false;
1854 switch (gli->mode) {
1856 last_lba = gli->max_lba;
1859 /* Cast lxt_cnt to u64 for multiply to be treated as 64bit op */
1860 last_lba = ((u64)rhte->lxt_cnt * MC_CHUNK_SIZE * gli->blk_len);
1861 last_lba /= CXLFLASH_BLOCK_SIZE;
1865 WARN(1, "Unsupported LUN mode!");
1868 verify->last_lba = last_lba;
1873 dev_dbg(dev, "%s: returning rc=%d llba=%llx\n",
1874 __func__, rc, verify->last_lba);
1879 * decode_ioctl() - translates an encoded ioctl to an easily identifiable string
1880 * @cmd: The ioctl command to decode.
1882 * Return: A string identifying the decoded ioctl.
1884 static char *decode_ioctl(int cmd)
1887 case DK_CXLFLASH_ATTACH:
1888 return __stringify_1(DK_CXLFLASH_ATTACH);
1889 case DK_CXLFLASH_USER_DIRECT:
1890 return __stringify_1(DK_CXLFLASH_USER_DIRECT);
1891 case DK_CXLFLASH_USER_VIRTUAL:
1892 return __stringify_1(DK_CXLFLASH_USER_VIRTUAL);
1893 case DK_CXLFLASH_VLUN_RESIZE:
1894 return __stringify_1(DK_CXLFLASH_VLUN_RESIZE);
1895 case DK_CXLFLASH_RELEASE:
1896 return __stringify_1(DK_CXLFLASH_RELEASE);
1897 case DK_CXLFLASH_DETACH:
1898 return __stringify_1(DK_CXLFLASH_DETACH);
1899 case DK_CXLFLASH_VERIFY:
1900 return __stringify_1(DK_CXLFLASH_VERIFY);
1901 case DK_CXLFLASH_VLUN_CLONE:
1902 return __stringify_1(DK_CXLFLASH_VLUN_CLONE);
1903 case DK_CXLFLASH_RECOVER_AFU:
1904 return __stringify_1(DK_CXLFLASH_RECOVER_AFU);
1905 case DK_CXLFLASH_MANAGE_LUN:
1906 return __stringify_1(DK_CXLFLASH_MANAGE_LUN);
1913 * cxlflash_disk_direct_open() - opens a direct (physical) disk
1914 * @sdev: SCSI device associated with LUN.
1915 * @arg: UDirect ioctl data structure.
1917 * On successful return, the user is informed of the resource handle
1918 * to be used to identify the direct lun and the size (in blocks) of
1919 * the direct lun in last LBA format.
1921 * Return: 0 on success, -errno on failure
1923 static int cxlflash_disk_direct_open(struct scsi_device *sdev, void *arg)
1925 struct cxlflash_cfg *cfg = shost_priv(sdev->host);
1926 struct device *dev = &cfg->dev->dev;
1927 struct afu *afu = cfg->afu;
1928 struct llun_info *lli = sdev->hostdata;
1929 struct glun_info *gli = lli->parent;
1931 struct dk_cxlflash_udirect *pphys = (struct dk_cxlflash_udirect *)arg;
1933 u64 ctxid = DECODE_CTXID(pphys->context_id),
1934 rctxid = pphys->context_id;
1937 u64 rsrc_handle = -1;
1938 u32 port = CHAN2PORT(sdev->channel);
1942 struct ctx_info *ctxi = NULL;
1943 struct sisl_rht_entry *rhte = NULL;
1945 dev_dbg(dev, "%s: ctxid=%llu ls=%llu\n", __func__, ctxid, lun_size);
1947 rc = cxlflash_lun_attach(gli, MODE_PHYSICAL, false);
1949 dev_dbg(dev, "%s: Failed attach to LUN (PHYSICAL)\n", __func__);
1953 ctxi = get_context(cfg, rctxid, lli, 0);
1954 if (unlikely(!ctxi)) {
1955 dev_dbg(dev, "%s: Bad context ctxid=%llu\n", __func__, ctxid);
1960 rhte = rhte_checkout(ctxi, lli);
1961 if (unlikely(!rhte)) {
1962 dev_dbg(dev, "%s: Too many opens ctxid=%lld\n",
1964 rc = -EMFILE; /* too many opens */
1968 rsrc_handle = (rhte - ctxi->rht_start);
1970 rht_format1(rhte, lli->lun_id[sdev->channel], ctxi->rht_perms, port);
1971 cxlflash_afu_sync(afu, ctxid, rsrc_handle, AFU_LW_SYNC);
1973 last_lba = gli->max_lba;
1974 pphys->hdr.return_flags = 0;
1975 pphys->last_lba = last_lba;
1976 pphys->rsrc_handle = rsrc_handle;
1981 dev_dbg(dev, "%s: returning handle=%llu rc=%d llba=%llu\n",
1982 __func__, rsrc_handle, rc, last_lba);
1986 cxlflash_lun_detach(gli);
1991 * ioctl_common() - common IOCTL handler for driver
1992 * @sdev: SCSI device associated with LUN.
1993 * @cmd: IOCTL command.
1995 * Handles common fencing operations that are valid for multiple ioctls. Always
1996 * allow through ioctls that are cleanup oriented in nature, even when operating
1997 * in a failed/terminating state.
1999 * Return: 0 on success, -errno on failure
2001 static int ioctl_common(struct scsi_device *sdev, int cmd)
2003 struct cxlflash_cfg *cfg = shost_priv(sdev->host);
2004 struct device *dev = &cfg->dev->dev;
2005 struct llun_info *lli = sdev->hostdata;
2008 if (unlikely(!lli)) {
2009 dev_dbg(dev, "%s: Unknown LUN\n", __func__);
2014 rc = check_state(cfg);
2015 if (unlikely(rc) && (cfg->state == STATE_FAILTERM)) {
2017 case DK_CXLFLASH_VLUN_RESIZE:
2018 case DK_CXLFLASH_RELEASE:
2019 case DK_CXLFLASH_DETACH:
2020 dev_dbg(dev, "%s: Command override rc=%d\n",
2031 * cxlflash_ioctl() - IOCTL handler for driver
2032 * @sdev: SCSI device associated with LUN.
2033 * @cmd: IOCTL command.
2034 * @arg: Userspace ioctl data structure.
2036 * A read/write semaphore is used to implement a 'drain' of currently
2037 * running ioctls. The read semaphore is taken at the beginning of each
2038 * ioctl thread and released upon concluding execution. Additionally the
2039 * semaphore should be released and then reacquired in any ioctl execution
2040 * path which will wait for an event to occur that is outside the scope of
2041 * the ioctl (i.e. an adapter reset). To drain the ioctls currently running,
2042 * a thread simply needs to acquire the write semaphore.
2044 * Return: 0 on success, -errno on failure
2046 int cxlflash_ioctl(struct scsi_device *sdev, int cmd, void __user *arg)
2048 typedef int (*sioctl) (struct scsi_device *, void *);
2050 struct cxlflash_cfg *cfg = shost_priv(sdev->host);
2051 struct device *dev = &cfg->dev->dev;
2052 struct afu *afu = cfg->afu;
2053 struct dk_cxlflash_hdr *hdr;
2054 char buf[sizeof(union cxlflash_ioctls)];
2056 bool known_ioctl = false;
2059 struct Scsi_Host *shost = sdev->host;
2060 sioctl do_ioctl = NULL;
2062 static const struct {
2065 } ioctl_tbl[] = { /* NOTE: order matters here */
2066 {sizeof(struct dk_cxlflash_attach), (sioctl)cxlflash_disk_attach},
2067 {sizeof(struct dk_cxlflash_udirect), cxlflash_disk_direct_open},
2068 {sizeof(struct dk_cxlflash_release), (sioctl)cxlflash_disk_release},
2069 {sizeof(struct dk_cxlflash_detach), (sioctl)cxlflash_disk_detach},
2070 {sizeof(struct dk_cxlflash_verify), (sioctl)cxlflash_disk_verify},
2071 {sizeof(struct dk_cxlflash_recover_afu), (sioctl)cxlflash_afu_recover},
2072 {sizeof(struct dk_cxlflash_manage_lun), (sioctl)cxlflash_manage_lun},
2073 {sizeof(struct dk_cxlflash_uvirtual), cxlflash_disk_virtual_open},
2074 {sizeof(struct dk_cxlflash_resize), (sioctl)cxlflash_vlun_resize},
2075 {sizeof(struct dk_cxlflash_clone), (sioctl)cxlflash_disk_clone},
2078 /* Hold read semaphore so we can drain if needed */
2079 down_read(&cfg->ioctl_rwsem);
2081 /* Restrict command set to physical support only for internal LUN */
2082 if (afu->internal_lun)
2084 case DK_CXLFLASH_RELEASE:
2085 case DK_CXLFLASH_USER_VIRTUAL:
2086 case DK_CXLFLASH_VLUN_RESIZE:
2087 case DK_CXLFLASH_VLUN_CLONE:
2088 dev_dbg(dev, "%s: %s not supported for lun_mode=%d\n",
2089 __func__, decode_ioctl(cmd), afu->internal_lun);
2091 goto cxlflash_ioctl_exit;
2095 case DK_CXLFLASH_ATTACH:
2096 case DK_CXLFLASH_USER_DIRECT:
2097 case DK_CXLFLASH_RELEASE:
2098 case DK_CXLFLASH_DETACH:
2099 case DK_CXLFLASH_VERIFY:
2100 case DK_CXLFLASH_RECOVER_AFU:
2101 case DK_CXLFLASH_USER_VIRTUAL:
2102 case DK_CXLFLASH_VLUN_RESIZE:
2103 case DK_CXLFLASH_VLUN_CLONE:
2104 dev_dbg(dev, "%s: %s (%08X) on dev(%d/%d/%d/%llu)\n",
2105 __func__, decode_ioctl(cmd), cmd, shost->host_no,
2106 sdev->channel, sdev->id, sdev->lun);
2107 rc = ioctl_common(sdev, cmd);
2109 goto cxlflash_ioctl_exit;
2113 case DK_CXLFLASH_MANAGE_LUN:
2115 idx = _IOC_NR(cmd) - _IOC_NR(DK_CXLFLASH_ATTACH);
2116 size = ioctl_tbl[idx].size;
2117 do_ioctl = ioctl_tbl[idx].ioctl;
2119 if (likely(do_ioctl))
2125 goto cxlflash_ioctl_exit;
2128 if (unlikely(copy_from_user(&buf, arg, size))) {
2129 dev_err(dev, "%s: copy_from_user() fail "
2130 "size=%lu cmd=%d (%s) arg=%p\n",
2131 __func__, size, cmd, decode_ioctl(cmd), arg);
2133 goto cxlflash_ioctl_exit;
2136 hdr = (struct dk_cxlflash_hdr *)&buf;
2137 if (hdr->version != DK_CXLFLASH_VERSION_0) {
2138 dev_dbg(dev, "%s: Version %u not supported for %s\n",
2139 __func__, hdr->version, decode_ioctl(cmd));
2141 goto cxlflash_ioctl_exit;
2144 if (hdr->rsvd[0] || hdr->rsvd[1] || hdr->rsvd[2] || hdr->return_flags) {
2145 dev_dbg(dev, "%s: Reserved/rflags populated\n", __func__);
2147 goto cxlflash_ioctl_exit;
2150 rc = do_ioctl(sdev, (void *)&buf);
2152 if (unlikely(copy_to_user(arg, &buf, size))) {
2153 dev_err(dev, "%s: copy_to_user() fail "
2154 "size=%lu cmd=%d (%s) arg=%p\n",
2155 __func__, size, cmd, decode_ioctl(cmd), arg);
2159 /* fall through to exit */
2161 cxlflash_ioctl_exit:
2162 up_read(&cfg->ioctl_rwsem);
2163 if (unlikely(rc && known_ioctl))
2164 dev_err(dev, "%s: ioctl %s (%08X) on dev(%d/%d/%d/%llu) "
2165 "returned rc %d\n", __func__,
2166 decode_ioctl(cmd), cmd, shost->host_no,
2167 sdev->channel, sdev->id, sdev->lun, rc);
2169 dev_dbg(dev, "%s: ioctl %s (%08X) on dev(%d/%d/%d/%llu) "
2170 "returned rc %d\n", __func__, decode_ioctl(cmd),
2171 cmd, shost->host_no, sdev->channel, sdev->id,