diff options
Diffstat (limited to 'drivers/scsi/cxlflash/superpipe.c')
| -rw-r--r-- | drivers/scsi/cxlflash/superpipe.c | 2218 |
1 files changed, 2218 insertions, 0 deletions
diff --git a/drivers/scsi/cxlflash/superpipe.c b/drivers/scsi/cxlflash/superpipe.c new file mode 100644 index 000000000..df0ebabbf --- /dev/null +++ b/drivers/scsi/cxlflash/superpipe.c @@ -0,0 +1,2218 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * CXL Flash Device Driver + * + * Written by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>, IBM Corporation + * Matthew R. Ochs <mrochs@linux.vnet.ibm.com>, IBM Corporation + * + * Copyright (C) 2015 IBM Corporation + */ + +#include <linux/delay.h> +#include <linux/file.h> +#include <linux/interrupt.h> +#include <linux/pci.h> +#include <linux/syscalls.h> +#include <asm/unaligned.h> + +#include <scsi/scsi.h> +#include <scsi/scsi_host.h> +#include <scsi/scsi_cmnd.h> +#include <scsi/scsi_eh.h> +#include <uapi/scsi/cxlflash_ioctl.h> + +#include "sislite.h" +#include "common.h" +#include "vlun.h" +#include "superpipe.h" + +struct cxlflash_global global; + +/** + * marshal_rele_to_resize() - translate release to resize structure + * @release: Source structure from which to translate/copy. + * @resize: Destination structure for the translate/copy. + */ +static void marshal_rele_to_resize(struct dk_cxlflash_release *release, + struct dk_cxlflash_resize *resize) +{ + resize->hdr = release->hdr; + resize->context_id = release->context_id; + resize->rsrc_handle = release->rsrc_handle; +} + +/** + * marshal_det_to_rele() - translate detach to release structure + * @detach: Destination structure for the translate/copy. + * @release: Source structure from which to translate/copy. + */ +static void marshal_det_to_rele(struct dk_cxlflash_detach *detach, + struct dk_cxlflash_release *release) +{ + release->hdr = detach->hdr; + release->context_id = detach->context_id; +} + +/** + * marshal_udir_to_rele() - translate udirect to release structure + * @udirect: Source structure from which to translate/copy. + * @release: Destination structure for the translate/copy. + */ +static void marshal_udir_to_rele(struct dk_cxlflash_udirect *udirect, + struct dk_cxlflash_release *release) +{ + release->hdr = udirect->hdr; + release->context_id = udirect->context_id; + release->rsrc_handle = udirect->rsrc_handle; +} + +/** + * cxlflash_free_errpage() - frees resources associated with global error page + */ +void cxlflash_free_errpage(void) +{ + + mutex_lock(&global.mutex); + if (global.err_page) { + __free_page(global.err_page); + global.err_page = NULL; + } + mutex_unlock(&global.mutex); +} + +/** + * cxlflash_stop_term_user_contexts() - stops/terminates known user contexts + * @cfg: Internal structure associated with the host. + * + * When the host needs to go down, all users must be quiesced and their + * memory freed. This is accomplished by putting the contexts in error + * state which will notify the user and let them 'drive' the tear down. + * Meanwhile, this routine camps until all user contexts have been removed. + * + * Note that the main loop in this routine will always execute at least once + * to flush the reset_waitq. + */ +void cxlflash_stop_term_user_contexts(struct cxlflash_cfg *cfg) +{ + struct device *dev = &cfg->dev->dev; + int i, found = true; + + cxlflash_mark_contexts_error(cfg); + + while (true) { + for (i = 0; i < MAX_CONTEXT; i++) + if (cfg->ctx_tbl[i]) { + found = true; + break; + } + + if (!found && list_empty(&cfg->ctx_err_recovery)) + return; + + dev_dbg(dev, "%s: Wait for user contexts to quiesce...\n", + __func__); + wake_up_all(&cfg->reset_waitq); + ssleep(1); + found = false; + } +} + +/** + * find_error_context() - locates a context by cookie on the error recovery list + * @cfg: Internal structure associated with the host. + * @rctxid: Desired context by id. + * @file: Desired context by file. + * + * Return: Found context on success, NULL on failure + */ +static struct ctx_info *find_error_context(struct cxlflash_cfg *cfg, u64 rctxid, + struct file *file) +{ + struct ctx_info *ctxi; + + list_for_each_entry(ctxi, &cfg->ctx_err_recovery, list) + if ((ctxi->ctxid == rctxid) || (ctxi->file == file)) + return ctxi; + + return NULL; +} + +/** + * get_context() - obtains a validated and locked context reference + * @cfg: Internal structure associated with the host. + * @rctxid: Desired context (raw, un-decoded format). + * @arg: LUN information or file associated with request. + * @ctx_ctrl: Control information to 'steer' desired lookup. + * + * NOTE: despite the name pid, in linux, current->pid actually refers + * to the lightweight process id (tid) and can change if the process is + * multi threaded. The tgid remains constant for the process and only changes + * when the process of fork. For all intents and purposes, think of tgid + * as a pid in the traditional sense. + * + * Return: Validated context on success, NULL on failure + */ +struct ctx_info *get_context(struct cxlflash_cfg *cfg, u64 rctxid, + void *arg, enum ctx_ctrl ctx_ctrl) +{ + struct device *dev = &cfg->dev->dev; + struct ctx_info *ctxi = NULL; + struct lun_access *lun_access = NULL; + struct file *file = NULL; + struct llun_info *lli = arg; + u64 ctxid = DECODE_CTXID(rctxid); + int rc; + pid_t pid = task_tgid_nr(current), ctxpid = 0; + + if (ctx_ctrl & CTX_CTRL_FILE) { + lli = NULL; + file = (struct file *)arg; + } + + if (ctx_ctrl & CTX_CTRL_CLONE) + pid = task_ppid_nr(current); + + if (likely(ctxid < MAX_CONTEXT)) { + while (true) { + mutex_lock(&cfg->ctx_tbl_list_mutex); + ctxi = cfg->ctx_tbl[ctxid]; + if (ctxi) + if ((file && (ctxi->file != file)) || + (!file && (ctxi->ctxid != rctxid))) + ctxi = NULL; + + if ((ctx_ctrl & CTX_CTRL_ERR) || + (!ctxi && (ctx_ctrl & CTX_CTRL_ERR_FALLBACK))) + ctxi = find_error_context(cfg, rctxid, file); + if (!ctxi) { + mutex_unlock(&cfg->ctx_tbl_list_mutex); + goto out; + } + + /* + * Need to acquire ownership of the context while still + * under the table/list lock to serialize with a remove + * thread. Use the 'try' to avoid stalling the + * table/list lock for a single context. + * + * Note that the lock order is: + * + * cfg->ctx_tbl_list_mutex -> ctxi->mutex + * + * Therefore release ctx_tbl_list_mutex before retrying. + */ + rc = mutex_trylock(&ctxi->mutex); + mutex_unlock(&cfg->ctx_tbl_list_mutex); + if (rc) + break; /* got the context's lock! */ + } + + if (ctxi->unavail) + goto denied; + + ctxpid = ctxi->pid; + if (likely(!(ctx_ctrl & CTX_CTRL_NOPID))) + if (pid != ctxpid) + goto denied; + + if (lli) { + list_for_each_entry(lun_access, &ctxi->luns, list) + if (lun_access->lli == lli) + goto out; + goto denied; + } + } + +out: + dev_dbg(dev, "%s: rctxid=%016llx ctxinfo=%p ctxpid=%u pid=%u " + "ctx_ctrl=%u\n", __func__, rctxid, ctxi, ctxpid, pid, + ctx_ctrl); + + return ctxi; + +denied: + mutex_unlock(&ctxi->mutex); + ctxi = NULL; + goto out; +} + +/** + * put_context() - release a context that was retrieved from get_context() + * @ctxi: Context to release. + * + * For now, releasing the context equates to unlocking it's mutex. + */ +void put_context(struct ctx_info *ctxi) +{ + mutex_unlock(&ctxi->mutex); +} + +/** + * afu_attach() - attach a context to the AFU + * @cfg: Internal structure associated with the host. + * @ctxi: Context to attach. + * + * Upon setting the context capabilities, they must be confirmed with + * a read back operation as the context might have been closed since + * the mailbox was unlocked. When this occurs, registration is failed. + * + * Return: 0 on success, -errno on failure + */ +static int afu_attach(struct cxlflash_cfg *cfg, struct ctx_info *ctxi) +{ + struct device *dev = &cfg->dev->dev; + struct afu *afu = cfg->afu; + struct sisl_ctrl_map __iomem *ctrl_map = ctxi->ctrl_map; + int rc = 0; + struct hwq *hwq = get_hwq(afu, PRIMARY_HWQ); + u64 val; + int i; + + /* Unlock cap and restrict user to read/write cmds in translated mode */ + readq_be(&ctrl_map->mbox_r); + val = (SISL_CTX_CAP_READ_CMD | SISL_CTX_CAP_WRITE_CMD); + writeq_be(val, &ctrl_map->ctx_cap); + val = readq_be(&ctrl_map->ctx_cap); + if (val != (SISL_CTX_CAP_READ_CMD | SISL_CTX_CAP_WRITE_CMD)) { + dev_err(dev, "%s: ctx may be closed val=%016llx\n", + __func__, val); + rc = -EAGAIN; + goto out; + } + + if (afu_is_ocxl_lisn(afu)) { + /* Set up the LISN effective address for each interrupt */ + for (i = 0; i < ctxi->irqs; i++) { + val = cfg->ops->get_irq_objhndl(ctxi->ctx, i); + writeq_be(val, &ctrl_map->lisn_ea[i]); + } + + /* Use primary HWQ PASID as identifier for all interrupts */ + val = hwq->ctx_hndl; + writeq_be(SISL_LISN_PASID(val, val), &ctrl_map->lisn_pasid[0]); + writeq_be(SISL_LISN_PASID(0UL, val), &ctrl_map->lisn_pasid[1]); + } + + /* Set up MMIO registers pointing to the RHT */ + writeq_be((u64)ctxi->rht_start, &ctrl_map->rht_start); + val = SISL_RHT_CNT_ID((u64)MAX_RHT_PER_CONTEXT, (u64)(hwq->ctx_hndl)); + writeq_be(val, &ctrl_map->rht_cnt_id); +out: + dev_dbg(dev, "%s: returning rc=%d\n", __func__, rc); + return rc; +} + +/** + * read_cap16() - issues a SCSI READ_CAP16 command + * @sdev: SCSI device associated with LUN. + * @lli: LUN destined for capacity request. + * + * The READ_CAP16 can take quite a while to complete. Should an EEH occur while + * in scsi_execute(), the EEH handler will attempt to recover. As part of the + * recovery, the handler drains all currently running ioctls, waiting until they + * have completed before proceeding with a reset. As this routine is used on the + * ioctl path, this can create a condition where the EEH handler becomes stuck, + * infinitely waiting for this ioctl thread. To avoid this behavior, temporarily + * unmark this thread as an ioctl thread by releasing the ioctl read semaphore. + * This will allow the EEH handler to proceed with a recovery while this thread + * is still running. Once the scsi_execute() returns, reacquire the ioctl read + * semaphore and check the adapter state in case it changed while inside of + * scsi_execute(). The state check will wait if the adapter is still being + * recovered or return a failure if the recovery failed. In the event that the + * adapter reset failed, simply return the failure as the ioctl would be unable + * to continue. + * + * Note that the above puts a requirement on this routine to only be called on + * an ioctl thread. + * + * Return: 0 on success, -errno on failure + */ +static int read_cap16(struct scsi_device *sdev, struct llun_info *lli) +{ + struct cxlflash_cfg *cfg = shost_priv(sdev->host); + struct device *dev = &cfg->dev->dev; + struct glun_info *gli = lli->parent; + struct scsi_sense_hdr sshdr; + u8 *cmd_buf = NULL; + u8 *scsi_cmd = NULL; + int rc = 0; + int result = 0; + int retry_cnt = 0; + u32 to = CMD_TIMEOUT * HZ; + +retry: + cmd_buf = kzalloc(CMD_BUFSIZE, GFP_KERNEL); + scsi_cmd = kzalloc(MAX_COMMAND_SIZE, GFP_KERNEL); + if (unlikely(!cmd_buf || !scsi_cmd)) { + rc = -ENOMEM; + goto out; + } + + scsi_cmd[0] = SERVICE_ACTION_IN_16; /* read cap(16) */ + scsi_cmd[1] = SAI_READ_CAPACITY_16; /* service action */ + put_unaligned_be32(CMD_BUFSIZE, &scsi_cmd[10]); + + dev_dbg(dev, "%s: %ssending cmd(%02x)\n", __func__, + retry_cnt ? "re" : "", scsi_cmd[0]); + + /* Drop the ioctl read semahpore across lengthy call */ + up_read(&cfg->ioctl_rwsem); + result = scsi_execute(sdev, scsi_cmd, DMA_FROM_DEVICE, cmd_buf, + CMD_BUFSIZE, NULL, &sshdr, to, CMD_RETRIES, + 0, 0, NULL); + down_read(&cfg->ioctl_rwsem); + rc = check_state(cfg); + if (rc) { + dev_err(dev, "%s: Failed state result=%08x\n", + __func__, result); + rc = -ENODEV; + goto out; + } + + if (result > 0 && scsi_sense_valid(&sshdr)) { + if (result & SAM_STAT_CHECK_CONDITION) { + switch (sshdr.sense_key) { + case NO_SENSE: + case RECOVERED_ERROR: + case NOT_READY: + result &= ~SAM_STAT_CHECK_CONDITION; + break; + case UNIT_ATTENTION: + switch (sshdr.asc) { + case 0x29: /* Power on Reset or Device Reset */ + fallthrough; + case 0x2A: /* Device capacity changed */ + case 0x3F: /* Report LUNs changed */ + /* Retry the command once more */ + if (retry_cnt++ < 1) { + kfree(cmd_buf); + kfree(scsi_cmd); + goto retry; + } + } + break; + default: + break; + } + } + } + + if (result) { + dev_err(dev, "%s: command failed, result=%08x\n", + __func__, result); + rc = -EIO; + goto out; + } + + /* + * Read cap was successful, grab values from the buffer; + * note that we don't need to worry about unaligned access + * as the buffer is allocated on an aligned boundary. + */ + mutex_lock(&gli->mutex); + gli->max_lba = be64_to_cpu(*((__be64 *)&cmd_buf[0])); + gli->blk_len = be32_to_cpu(*((__be32 *)&cmd_buf[8])); + mutex_unlock(&gli->mutex); + +out: + kfree(cmd_buf); + kfree(scsi_cmd); + + dev_dbg(dev, "%s: maxlba=%lld blklen=%d rc=%d\n", + __func__, gli->max_lba, gli->blk_len, rc); + return rc; +} + +/** + * get_rhte() - obtains validated resource handle table entry reference + * @ctxi: Context owning the resource handle. + * @rhndl: Resource handle associated with entry. + * @lli: LUN associated with request. + * + * Return: Validated RHTE on success, NULL on failure + */ +struct sisl_rht_entry *get_rhte(struct ctx_info *ctxi, res_hndl_t rhndl, + struct llun_info *lli) +{ + struct cxlflash_cfg *cfg = ctxi->cfg; + struct device *dev = &cfg->dev->dev; + struct sisl_rht_entry *rhte = NULL; + + if (unlikely(!ctxi->rht_start)) { + dev_dbg(dev, "%s: Context does not have allocated RHT\n", + __func__); + goto out; + } + + if (unlikely(rhndl >= MAX_RHT_PER_CONTEXT)) { + dev_dbg(dev, "%s: Bad resource handle rhndl=%d\n", + __func__, rhndl); + goto out; + } + + if (unlikely(ctxi->rht_lun[rhndl] != lli)) { + dev_dbg(dev, "%s: Bad resource handle LUN rhndl=%d\n", + __func__, rhndl); + goto out; + } + + rhte = &ctxi->rht_start[rhndl]; + if (unlikely(rhte->nmask == 0)) { + dev_dbg(dev, "%s: Unopened resource handle rhndl=%d\n", + __func__, rhndl); + rhte = NULL; + goto out; + } + +out: + return rhte; +} + +/** + * rhte_checkout() - obtains free/empty resource handle table entry + * @ctxi: Context owning the resource handle. + * @lli: LUN associated with request. + * + * Return: Free RHTE on success, NULL on failure + */ +struct sisl_rht_entry *rhte_checkout(struct ctx_info *ctxi, + struct llun_info *lli) +{ + struct cxlflash_cfg *cfg = ctxi->cfg; + struct device *dev = &cfg->dev->dev; + struct sisl_rht_entry *rhte = NULL; + int i; + + /* Find a free RHT entry */ + for (i = 0; i < MAX_RHT_PER_CONTEXT; i++) + if (ctxi->rht_start[i].nmask == 0) { + rhte = &ctxi->rht_start[i]; + ctxi->rht_out++; + break; + } + + if (likely(rhte)) + ctxi->rht_lun[i] = lli; + + dev_dbg(dev, "%s: returning rhte=%p index=%d\n", __func__, rhte, i); + return rhte; +} + +/** + * rhte_checkin() - releases a resource handle table entry + * @ctxi: Context owning the resource handle. + * @rhte: RHTE to release. + */ +void rhte_checkin(struct ctx_info *ctxi, + struct sisl_rht_entry *rhte) +{ + u32 rsrc_handle = rhte - ctxi->rht_start; + + rhte->nmask = 0; + rhte->fp = 0; + ctxi->rht_out--; + ctxi->rht_lun[rsrc_handle] = NULL; + ctxi->rht_needs_ws[rsrc_handle] = false; +} + +/** + * rht_format1() - populates a RHTE for format 1 + * @rhte: RHTE to populate. + * @lun_id: LUN ID of LUN associated with RHTE. + * @perm: Desired permissions for RHTE. + * @port_sel: Port selection mask + */ +static void rht_format1(struct sisl_rht_entry *rhte, u64 lun_id, u32 perm, + u32 port_sel) +{ + /* + * Populate the Format 1 RHT entry for direct access (physical + * LUN) using the synchronization sequence defined in the + * SISLite specification. + */ + struct sisl_rht_entry_f1 dummy = { 0 }; + struct sisl_rht_entry_f1 *rhte_f1 = (struct sisl_rht_entry_f1 *)rhte; + + memset(rhte_f1, 0, sizeof(*rhte_f1)); + rhte_f1->fp = SISL_RHT_FP(1U, 0); + dma_wmb(); /* Make setting of format bit visible */ + + rhte_f1->lun_id = lun_id; + dma_wmb(); /* Make setting of LUN id visible */ + + /* + * Use a dummy RHT Format 1 entry to build the second dword + * of the entry that must be populated in a single write when + * enabled (valid bit set to TRUE). + */ + dummy.valid = 0x80; + dummy.fp = SISL_RHT_FP(1U, perm); + dummy.port_sel = port_sel; + rhte_f1->dw = dummy.dw; + + dma_wmb(); /* Make remaining RHT entry fields visible */ +} + +/** + * cxlflash_lun_attach() - attaches a user to a LUN and manages the LUN's mode + * @gli: LUN to attach. + * @mode: Desired mode of the LUN. + * @locked: Mutex status on current thread. + * + * Return: 0 on success, -errno on failure + */ +int cxlflash_lun_attach(struct glun_info *gli, enum lun_mode mode, bool locked) +{ + int rc = 0; + + if (!locked) + mutex_lock(&gli->mutex); + + if (gli->mode == MODE_NONE) + gli->mode = mode; + else if (gli->mode != mode) { + pr_debug("%s: gli_mode=%d requested_mode=%d\n", + __func__, gli->mode, mode); + rc = -EINVAL; + goto out; + } + + gli->users++; + WARN_ON(gli->users <= 0); +out: + pr_debug("%s: Returning rc=%d gli->mode=%u gli->users=%u\n", + __func__, rc, gli->mode, gli->users); + if (!locked) + mutex_unlock(&gli->mutex); + return rc; +} + +/** + * cxlflash_lun_detach() - detaches a user from a LUN and resets the LUN's mode + * @gli: LUN to detach. + * + * When resetting the mode, terminate block allocation resources as they + * are no longer required (service is safe to call even when block allocation + * resources were not present - such as when transitioning from physical mode). + * These resources will be reallocated when needed (subsequent transition to + * virtual mode). + */ +void cxlflash_lun_detach(struct glun_info *gli) +{ + mutex_lock(&gli->mutex); + WARN_ON(gli->mode == MODE_NONE); + if (--gli->users == 0) { + gli->mode = MODE_NONE; + cxlflash_ba_terminate(&gli->blka.ba_lun); + } + pr_debug("%s: gli->users=%u\n", __func__, gli->users); + WARN_ON(gli->users < 0); + mutex_unlock(&gli->mutex); +} + +/** + * _cxlflash_disk_release() - releases the specified resource entry + * @sdev: SCSI device associated with LUN. + * @ctxi: Context owning resources. + * @release: Release ioctl data structure. + * + * For LUNs in virtual mode, the virtual LUN associated with the specified + * resource handle is resized to 0 prior to releasing the RHTE. Note that the + * AFU sync should _not_ be performed when the context is sitting on the error + * recovery list. A context on the error recovery list is not known to the AFU + * due to reset. When the context is recovered, it will be reattached and made + * known again to the AFU. + * + * Return: 0 on success, -errno on failure + */ +int _cxlflash_disk_release(struct scsi_device *sdev, + struct ctx_info *ctxi, + struct dk_cxlflash_release *release) +{ + struct cxlflash_cfg *cfg = shost_priv(sdev->host); + struct device *dev = &cfg->dev->dev; + struct llun_info *lli = sdev->hostdata; + struct glun_info *gli = lli->parent; + struct afu *afu = cfg->afu; + bool put_ctx = false; + + struct dk_cxlflash_resize size; + res_hndl_t rhndl = release->rsrc_handle; + + int rc = 0; + int rcr = 0; + u64 ctxid = DECODE_CTXID(release->context_id), + rctxid = release->context_id; + + struct sisl_rht_entry *rhte; + struct sisl_rht_entry_f1 *rhte_f1; + + dev_dbg(dev, "%s: ctxid=%llu rhndl=%llu gli->mode=%u gli->users=%u\n", + __func__, ctxid, release->rsrc_handle, gli->mode, gli->users); + + if (!ctxi) { + ctxi = get_context(cfg, rctxid, lli, CTX_CTRL_ERR_FALLBACK); + if (unlikely(!ctxi)) { + dev_dbg(dev, "%s: Bad context ctxid=%llu\n", + __func__, ctxid); + rc = -EINVAL; + goto out; + } + + put_ctx = true; + } + + rhte = get_rhte(ctxi, rhndl, lli); + if (unlikely(!rhte)) { + dev_dbg(dev, "%s: Bad resource handle rhndl=%d\n", + __func__, rhndl); + rc = -EINVAL; + goto out; + } + + /* + * Resize to 0 for virtual LUNS by setting the size + * to 0. This will clear LXT_START and LXT_CNT fields + * in the RHT entry and properly sync with the AFU. + * + * Afterwards we clear the remaining fields. + */ + switch (gli->mode) { + case MODE_VIRTUAL: + marshal_rele_to_resize(release, &size); + size.req_size = 0; + rc = _cxlflash_vlun_resize(sdev, ctxi, &size); + if (rc) { + dev_dbg(dev, "%s: resize failed rc %d\n", __func__, rc); + goto out; + } + + break; + case MODE_PHYSICAL: + /* + * Clear the Format 1 RHT entry for direct access + * (physical LUN) using the synchronization sequence + * defined in the SISLite specification. + */ + rhte_f1 = (struct sisl_rht_entry_f1 *)rhte; + + rhte_f1->valid = 0; + dma_wmb(); /* Make revocation of RHT entry visible */ + + rhte_f1->lun_id = 0; + dma_wmb(); /* Make clearing of LUN id visible */ + + rhte_f1->dw = 0; + dma_wmb(); /* Make RHT entry bottom-half clearing visible */ + + if (!ctxi->err_recovery_active) { + rcr = cxlflash_afu_sync(afu, ctxid, rhndl, AFU_HW_SYNC); + if (unlikely(rcr)) + dev_dbg(dev, "%s: AFU sync failed rc=%d\n", + __func__, rcr); + } + break; + default: + WARN(1, "Unsupported LUN mode!"); + goto out; + } + + rhte_checkin(ctxi, rhte); + cxlflash_lun_detach(gli); + +out: + if (put_ctx) + put_context(ctxi); + dev_dbg(dev, "%s: returning rc=%d\n", __func__, rc); + return rc; +} + +int cxlflash_disk_release(struct scsi_device *sdev, + struct dk_cxlflash_release *release) +{ + return _cxlflash_disk_release(sdev, NULL, release); +} + +/** + * destroy_context() - releases a context + * @cfg: Internal structure associated with the host. + * @ctxi: Context to release. + * + * This routine is safe to be called with a a non-initialized context. + * Also note that the routine conditionally checks for the existence + * of the context control map before clearing the RHT registers and + * context capabilities because it is possible to destroy a context + * while the context is in the error state (previous mapping was + * removed [so there is no need to worry about clearing] and context + * is waiting for a new mapping). + */ +static void destroy_context(struct cxlflash_cfg *cfg, + struct ctx_info *ctxi) +{ + struct afu *afu = cfg->afu; + + if (ctxi->initialized) { + WARN_ON(!list_empty(&ctxi->luns)); + + /* Clear RHT registers and drop all capabilities for context */ + if (afu->afu_map && ctxi->ctrl_map) { + writeq_be(0, &ctxi->ctrl_map->rht_start); + writeq_be(0, &ctxi->ctrl_map->rht_cnt_id); + writeq_be(0, &ctxi->ctrl_map->ctx_cap); + } + } + + /* Free memory associated with context */ + free_page((ulong)ctxi->rht_start); + kfree(ctxi->rht_needs_ws); + kfree(ctxi->rht_lun); + kfree(ctxi); +} + +/** + * create_context() - allocates and initializes a context + * @cfg: Internal structure associated with the host. + * + * Return: Allocated context on success, NULL on failure + */ +static struct ctx_info *create_context(struct cxlflash_cfg *cfg) +{ + struct device *dev = &cfg->dev->dev; + struct ctx_info *ctxi = NULL; + struct llun_info **lli = NULL; + u8 *ws = NULL; + struct sisl_rht_entry *rhte; + + ctxi = kzalloc(sizeof(*ctxi), GFP_KERNEL); + lli = kzalloc((MAX_RHT_PER_CONTEXT * sizeof(*lli)), GFP_KERNEL); + ws = kzalloc((MAX_RHT_PER_CONTEXT * sizeof(*ws)), GFP_KERNEL); + if (unlikely(!ctxi || !lli || !ws)) { + dev_err(dev, "%s: Unable to allocate context\n", __func__); + goto err; + } + + rhte = (struct sisl_rht_entry *)get_zeroed_page(GFP_KERNEL); + if (unlikely(!rhte)) { + dev_err(dev, "%s: Unable to allocate RHT\n", __func__); + goto err; + } + + ctxi->rht_lun = lli; + ctxi->rht_needs_ws = ws; + ctxi->rht_start = rhte; +out: + return ctxi; + +err: + kfree(ws); + kfree(lli); + kfree(ctxi); + ctxi = NULL; + goto out; +} + +/** + * init_context() - initializes a previously allocated context + * @ctxi: Previously allocated context + * @cfg: Internal structure associated with the host. + * @ctx: Previously obtained context cookie. + * @ctxid: Previously obtained process element associated with CXL context. + * @file: Previously obtained file associated with CXL context. + * @perms: User-specified permissions. + * @irqs: User-specified number of interrupts. + */ +static void init_context(struct ctx_info *ctxi, struct cxlflash_cfg *cfg, + void *ctx, int ctxid, struct file *file, u32 perms, + u64 irqs) +{ + struct afu *afu = cfg->afu; + + ctxi->rht_perms = perms; + ctxi->ctrl_map = &afu->afu_map->ctrls[ctxid].ctrl; + ctxi->ctxid = ENCODE_CTXID(ctxi, ctxid); + ctxi->irqs = irqs; + ctxi->pid = task_tgid_nr(current); /* tgid = pid */ + ctxi->ctx = ctx; + ctxi->cfg = cfg; + ctxi->file = file; + ctxi->initialized = true; + mutex_init(&ctxi->mutex); + kref_init(&ctxi->kref); + INIT_LIST_HEAD(&ctxi->luns); + INIT_LIST_HEAD(&ctxi->list); /* initialize for list_empty() */ +} + +/** + * remove_context() - context kref release handler + * @kref: Kernel reference associated with context to be removed. + * + * When a context no longer has any references it can safely be removed + * from global access and destroyed. Note that it is assumed the thread + * relinquishing access to the context holds its mutex. + */ +static void remove_context(struct kref *kref) +{ + struct ctx_info *ctxi = container_of(kref, struct ctx_info, kref); + struct cxlflash_cfg *cfg = ctxi->cfg; + u64 ctxid = DECODE_CTXID(ctxi->ctxid); + + /* Remove context from table/error list */ + WARN_ON(!mutex_is_locked(&ctxi->mutex)); + ctxi->unavail = true; + mutex_unlock(&ctxi->mutex); + mutex_lock(&cfg->ctx_tbl_list_mutex); + mutex_lock(&ctxi->mutex); + + if (!list_empty(&ctxi->list)) + list_del(&ctxi->list); + cfg->ctx_tbl[ctxid] = NULL; + mutex_unlock(&cfg->ctx_tbl_list_mutex); + mutex_unlock(&ctxi->mutex); + + /* Context now completely uncoupled/unreachable */ + destroy_context(cfg, ctxi); +} + +/** + * _cxlflash_disk_detach() - detaches a LUN from a context + * @sdev: SCSI device associated with LUN. + * @ctxi: Context owning resources. + * @detach: Detach ioctl data structure. + * + * As part of the detach, all per-context resources associated with the LUN + * are cleaned up. When detaching the last LUN for a context, the context + * itself is cleaned up and released. + * + * Return: 0 on success, -errno on failure + */ +static int _cxlflash_disk_detach(struct scsi_device *sdev, + struct ctx_info *ctxi, + struct dk_cxlflash_detach *detach) +{ + struct cxlflash_cfg *cfg = shost_priv(sdev->host); + struct device *dev = &cfg->dev->dev; + struct llun_info *lli = sdev->hostdata; + struct lun_access *lun_access, *t; + struct dk_cxlflash_release rel; + bool put_ctx = false; + + int i; + int rc = 0; + u64 ctxid = DECODE_CTXID(detach->context_id), + rctxid = detach->context_id; + + dev_dbg(dev, "%s: ctxid=%llu\n", __func__, ctxid); + + if (!ctxi) { + ctxi = get_context(cfg, rctxid, lli, CTX_CTRL_ERR_FALLBACK); + if (unlikely(!ctxi)) { + dev_dbg(dev, "%s: Bad context ctxid=%llu\n", + __func__, ctxid); + rc = -EINVAL; + goto out; + } + + put_ctx = true; + } + + /* Cleanup outstanding resources tied to this LUN */ + if (ctxi->rht_out) { + marshal_det_to_rele(detach, &rel); + for (i = 0; i < MAX_RHT_PER_CONTEXT; i++) { + if (ctxi->rht_lun[i] == lli) { + rel.rsrc_handle = i; + _cxlflash_disk_release(sdev, ctxi, &rel); + } + + /* No need to loop further if we're done */ + if (ctxi->rht_out == 0) + break; + } + } + + /* Take our LUN out of context, free the node */ + list_for_each_entry_safe(lun_access, t, &ctxi->luns, list) + if (lun_access->lli == lli) { + list_del(&lun_access->list); + kfree(lun_access); + lun_access = NULL; + break; + } + + /* + * Release the context reference and the sdev reference that + * bound this LUN to the context. + */ + if (kref_put(&ctxi->kref, remove_context)) + put_ctx = false; + scsi_device_put(sdev); +out: + if (put_ctx) + put_context(ctxi); + dev_dbg(dev, "%s: returning rc=%d\n", __func__, rc); + return rc; +} + +static int cxlflash_disk_detach(struct scsi_device *sdev, + struct dk_cxlflash_detach *detach) +{ + return _cxlflash_disk_detach(sdev, NULL, detach); +} + +/** + * cxlflash_cxl_release() - release handler for adapter file descriptor + * @inode: File-system inode associated with fd. + * @file: File installed with adapter file descriptor. + * + * This routine is the release handler for the fops registered with + * the CXL services on an initial attach for a context. It is called + * when a close (explicity by the user or as part of a process tear + * down) is performed on the adapter file descriptor returned to the + * user. The user should be aware that explicitly performing a close + * considered catastrophic and subsequent usage of the superpipe API + * with previously saved off tokens will fail. + * + * This routine derives the context reference and calls detach for + * each LUN associated with the context.The final detach operation + * causes the context itself to be freed. With exception to when the + * CXL process element (context id) lookup fails (a case that should + * theoretically never occur), every call into this routine results + * in a complete freeing of a context. + * + * Detaching the LUN is typically an ioctl() operation and the underlying + * code assumes that ioctl_rwsem has been acquired as a reader. To support + * that design point, the semaphore is acquired and released around detach. + * + * Return: 0 on success + */ +static int cxlflash_cxl_release(struct inode *inode, struct file *file) +{ + struct cxlflash_cfg *cfg = container_of(file->f_op, struct cxlflash_cfg, + cxl_fops); + void *ctx = cfg->ops->fops_get_context(file); + struct device *dev = &cfg->dev->dev; + struct ctx_info *ctxi = NULL; + struct dk_cxlflash_detach detach = { { 0 }, 0 }; + struct lun_access *lun_access, *t; + enum ctx_ctrl ctrl = CTX_CTRL_ERR_FALLBACK | CTX_CTRL_FILE; + int ctxid; + + ctxid = cfg->ops->process_element(ctx); + if (unlikely(ctxid < 0)) { + dev_err(dev, "%s: Context %p was closed ctxid=%d\n", + __func__, ctx, ctxid); + goto out; + } + + ctxi = get_context(cfg, ctxid, file, ctrl); + if (unlikely(!ctxi)) { + ctxi = get_context(cfg, ctxid, file, ctrl | CTX_CTRL_CLONE); + if (!ctxi) { + dev_dbg(dev, "%s: ctxid=%d already free\n", + __func__, ctxid); + goto out_release; + } + + dev_dbg(dev, "%s: Another process owns ctxid=%d\n", + __func__, ctxid); + put_context(ctxi); + goto out; + } + + dev_dbg(dev, "%s: close for ctxid=%d\n", __func__, ctxid); + + down_read(&cfg->ioctl_rwsem); + detach.context_id = ctxi->ctxid; + list_for_each_entry_safe(lun_access, t, &ctxi->luns, list) + _cxlflash_disk_detach(lun_access->sdev, ctxi, &detach); + up_read(&cfg->ioctl_rwsem); +out_release: + cfg->ops->fd_release(inode, file); +out: + dev_dbg(dev, "%s: returning\n", __func__); + return 0; +} + +/** + * unmap_context() - clears a previously established mapping + * @ctxi: Context owning the mapping. + * + * This routine is used to switch between the error notification page + * (dummy page of all 1's) and the real mapping (established by the CXL + * fault handler). + */ +static void unmap_context(struct ctx_info *ctxi) +{ + unmap_mapping_range(ctxi->file->f_mapping, 0, 0, 1); +} + +/** + * get_err_page() - obtains and allocates the error notification page + * @cfg: Internal structure associated with the host. + * + * Return: error notification page on success, NULL on failure + */ +static struct page *get_err_page(struct cxlflash_cfg *cfg) +{ + struct page *err_page = global.err_page; + struct device *dev = &cfg->dev->dev; + + if (unlikely(!err_page)) { + err_page = alloc_page(GFP_KERNEL); + if (unlikely(!err_page)) { + dev_err(dev, "%s: Unable to allocate err_page\n", + __func__); + goto out; + } + + memset(page_address(err_page), -1, PAGE_SIZE); + + /* Serialize update w/ other threads to avoid a leak */ + mutex_lock(&global.mutex); + if (likely(!global.err_page)) + global.err_page = err_page; + else { + __free_page(err_page); + err_page = global.err_page; + } + mutex_unlock(&global.mutex); + } + +out: + dev_dbg(dev, "%s: returning err_page=%p\n", __func__, err_page); + return err_page; +} + +/** + * cxlflash_mmap_fault() - mmap fault handler for adapter file descriptor + * @vmf: VM fault associated with current fault. + * + * To support error notification via MMIO, faults are 'caught' by this routine + * that was inserted before passing back the adapter file descriptor on attach. + * When a fault occurs, this routine evaluates if error recovery is active and + * if so, installs the error page to 'notify' the user about the error state. + * During normal operation, the fault is simply handled by the original fault + * handler that was installed by CXL services as part of initializing the + * adapter file descriptor. The VMA's page protection bits are toggled to + * indicate cached/not-cached depending on the memory backing the fault. + * + * Return: 0 on success, VM_FAULT_SIGBUS on failure + */ +static vm_fault_t cxlflash_mmap_fault(struct vm_fault *vmf) +{ + struct vm_area_struct *vma = vmf->vma; + struct file *file = vma->vm_file; + struct cxlflash_cfg *cfg = container_of(file->f_op, struct cxlflash_cfg, + cxl_fops); + void *ctx = cfg->ops->fops_get_context(file); + struct device *dev = &cfg->dev->dev; + struct ctx_info *ctxi = NULL; + struct page *err_page = NULL; + enum ctx_ctrl ctrl = CTX_CTRL_ERR_FALLBACK | CTX_CTRL_FILE; + vm_fault_t rc = 0; + int ctxid; + + ctxid = cfg->ops->process_element(ctx); + if (unlikely(ctxid < 0)) { + dev_err(dev, "%s: Context %p was closed ctxid=%d\n", + __func__, ctx, ctxid); + goto err; + } + + ctxi = get_context(cfg, ctxid, file, ctrl); + if (unlikely(!ctxi)) { + dev_dbg(dev, "%s: Bad context ctxid=%d\n", __func__, ctxid); + goto err; + } + + dev_dbg(dev, "%s: fault for context %d\n", __func__, ctxid); + + if (likely(!ctxi->err_recovery_active)) { + vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); + rc = ctxi->cxl_mmap_vmops->fault(vmf); + } else { + dev_dbg(dev, "%s: err recovery active, use err_page\n", + __func__); + + err_page = get_err_page(cfg); + if (unlikely(!err_page)) { + dev_err(dev, "%s: Could not get err_page\n", __func__); + rc = VM_FAULT_RETRY; + goto out; + } + + get_page(err_page); + vmf->page = err_page; + vma->vm_page_prot = pgprot_cached(vma->vm_page_prot); + } + +out: + if (likely(ctxi)) + put_context(ctxi); + dev_dbg(dev, "%s: returning rc=%x\n", __func__, rc); + return rc; + +err: + rc = VM_FAULT_SIGBUS; + goto out; +} + +/* + * Local MMAP vmops to 'catch' faults + */ +static const struct vm_operations_struct cxlflash_mmap_vmops = { + .fault = cxlflash_mmap_fault, +}; + +/** + * cxlflash_cxl_mmap() - mmap handler for adapter file descriptor + * @file: File installed with adapter file descriptor. + * @vma: VM area associated with mapping. + * + * Installs local mmap vmops to 'catch' faults for error notification support. + * + * Return: 0 on success, -errno on failure + */ +static int cxlflash_cxl_mmap(struct file *file, struct vm_area_struct *vma) +{ + struct cxlflash_cfg *cfg = container_of(file->f_op, struct cxlflash_cfg, + cxl_fops); + void *ctx = cfg->ops->fops_get_context(file); + struct device *dev = &cfg->dev->dev; + struct ctx_info *ctxi = NULL; + enum ctx_ctrl ctrl = CTX_CTRL_ERR_FALLBACK | CTX_CTRL_FILE; + int ctxid; + int rc = 0; + + ctxid = cfg->ops->process_element(ctx); + if (unlikely(ctxid < 0)) { + dev_err(dev, "%s: Context %p was closed ctxid=%d\n", + __func__, ctx, ctxid); + rc = -EIO; + goto out; + } + + ctxi = get_context(cfg, ctxid, file, ctrl); + if (unlikely(!ctxi)) { + dev_dbg(dev, "%s: Bad context ctxid=%d\n", __func__, ctxid); + rc = -EIO; + goto out; + } + + dev_dbg(dev, "%s: mmap for context %d\n", __func__, ctxid); + + rc = cfg->ops->fd_mmap(file, vma); + if (likely(!rc)) { + /* Insert ourself in the mmap fault handler path */ + ctxi->cxl_mmap_vmops = vma->vm_ops; + vma->vm_ops = &cxlflash_mmap_vmops; + } + +out: + if (likely(ctxi)) + put_context(ctxi); + return rc; +} + +const struct file_operations cxlflash_cxl_fops = { + .owner = THIS_MODULE, + .mmap = cxlflash_cxl_mmap, + .release = cxlflash_cxl_release, +}; + +/** + * cxlflash_mark_contexts_error() - move contexts to error state and list + * @cfg: Internal structure associated with the host. + * + * A context is only moved over to the error list when there are no outstanding + * references to it. This ensures that a running operation has completed. + * + * Return: 0 on success, -errno on failure + */ +int cxlflash_mark_contexts_error(struct cxlflash_cfg *cfg) +{ + int i, rc = 0; + struct ctx_info *ctxi = NULL; + + mutex_lock(&cfg->ctx_tbl_list_mutex); + + for (i = 0; i < MAX_CONTEXT; i++) { + ctxi = cfg->ctx_tbl[i]; + if (ctxi) { + mutex_lock(&ctxi->mutex); + cfg->ctx_tbl[i] = NULL; + list_add(&ctxi->list, &cfg->ctx_err_recovery); + ctxi->err_recovery_active = true; + ctxi->ctrl_map = NULL; + unmap_context(ctxi); + mutex_unlock(&ctxi->mutex); + } + } + + mutex_unlock(&cfg->ctx_tbl_list_mutex); + return rc; +} + +/* + * Dummy NULL fops + */ +static const struct file_operations null_fops = { + .owner = THIS_MODULE, +}; + +/** + * check_state() - checks and responds to the current adapter state + * @cfg: Internal structure associated with the host. + * + * This routine can block and should only be used on process context. + * It assumes that the caller is an ioctl thread and holding the ioctl + * read semaphore. This is temporarily let up across the wait to allow + * for draining actively running ioctls. Also note that when waking up + * from waiting in reset, the state is unknown and must be checked again + * before proceeding. + * + * Return: 0 on success, -errno on failure + */ +int check_state(struct cxlflash_cfg *cfg) +{ + struct device *dev = &cfg->dev->dev; + int rc = 0; + +retry: + switch (cfg->state) { + case STATE_RESET: + dev_dbg(dev, "%s: Reset state, going to wait...\n", __func__); + up_read(&cfg->ioctl_rwsem); + rc = wait_event_interruptible(cfg->reset_waitq, + cfg->state != STATE_RESET); + down_read(&cfg->ioctl_rwsem); + if (unlikely(rc)) + break; + goto retry; + case STATE_FAILTERM: + dev_dbg(dev, "%s: Failed/Terminating\n", __func__); + rc = -ENODEV; + break; + default: + break; + } + + return rc; +} + +/** + * cxlflash_disk_attach() - attach a LUN to a context + * @sdev: SCSI device associated with LUN. + * @attach: Attach ioctl data structure. + * + * Creates a context and attaches LUN to it. A LUN can only be attached + * one time to a context (subsequent attaches for the same context/LUN pair + * are not supported). Additional LUNs can be attached to a context by + * specifying the 'reuse' flag defined in the cxlflash_ioctl.h header. + * + * Return: 0 on success, -errno on failure + */ +static int cxlflash_disk_attach(struct scsi_device *sdev, + struct dk_cxlflash_attach *attach) +{ + struct cxlflash_cfg *cfg = shost_priv(sdev->host); + struct device *dev = &cfg->dev->dev; + struct afu *afu = cfg->afu; + struct llun_info *lli = sdev->hostdata; + struct glun_info *gli = lli->parent; + struct ctx_info *ctxi = NULL; + struct lun_access *lun_access = NULL; + int rc = 0; + u32 perms; + int ctxid = -1; + u64 irqs = attach->num_interrupts; + u64 flags = 0UL; + u64 rctxid = 0UL; + struct file *file = NULL; + + void *ctx = NULL; + + int fd = -1; + + if (irqs > 4) { + dev_dbg(dev, "%s: Cannot support this many interrupts %llu\n", + __func__, irqs); + rc = -EINVAL; + goto out; + } + + if (gli->max_lba == 0) { + dev_dbg(dev, "%s: No capacity info for LUN=%016llx\n", + __func__, lli->lun_id[sdev->channel]); + rc = read_cap16(sdev, lli); + if (rc) { + dev_err(dev, "%s: Invalid device rc=%d\n", + __func__, rc); + rc = -ENODEV; + goto out; + } + dev_dbg(dev, "%s: LBA = %016llx\n", __func__, gli->max_lba); + dev_dbg(dev, "%s: BLK_LEN = %08x\n", __func__, gli->blk_len); + } + + if (attach->hdr.flags & DK_CXLFLASH_ATTACH_REUSE_CONTEXT) { + rctxid = attach->context_id; + ctxi = get_context(cfg, rctxid, NULL, 0); + if (!ctxi) { + dev_dbg(dev, "%s: Bad context rctxid=%016llx\n", + __func__, rctxid); + rc = -EINVAL; + goto out; + } + + list_for_each_entry(lun_access, &ctxi->luns, list) + if (lun_access->lli == lli) { + dev_dbg(dev, "%s: Already attached\n", + __func__); + rc = -EINVAL; + goto out; + } + } + + rc = scsi_device_get(sdev); + if (unlikely(rc)) { + dev_err(dev, "%s: Unable to get sdev reference\n", __func__); + goto out; + } + + lun_access = kzalloc(sizeof(*lun_access), GFP_KERNEL); + if (unlikely(!lun_access)) { + dev_err(dev, "%s: Unable to allocate lun_access\n", __func__); + rc = -ENOMEM; + goto err; + } + + lun_access->lli = lli; + lun_access->sdev = sdev; + + /* Non-NULL context indicates reuse (another context reference) */ + if (ctxi) { + dev_dbg(dev, "%s: Reusing context for LUN rctxid=%016llx\n", + __func__, rctxid); + kref_get(&ctxi->kref); + list_add(&lun_access->list, &ctxi->luns); + goto out_attach; + } + + ctxi = create_context(cfg); + if (unlikely(!ctxi)) { + dev_err(dev, "%s: Failed to create context ctxid=%d\n", + __func__, ctxid); + rc = -ENOMEM; + goto err; + } + + ctx = cfg->ops->dev_context_init(cfg->dev, cfg->afu_cookie); + if (IS_ERR_OR_NULL(ctx)) { + dev_err(dev, "%s: Could not initialize context %p\n", + __func__, ctx); + rc = -ENODEV; + goto err; + } + + rc = cfg->ops->start_work(ctx, irqs); + if (unlikely(rc)) { + dev_dbg(dev, "%s: Could not start context rc=%d\n", + __func__, rc); + goto err; + } + + ctxid = cfg->ops->process_element(ctx); + if (unlikely((ctxid >= MAX_CONTEXT) || (ctxid < 0))) { + dev_err(dev, "%s: ctxid=%d invalid\n", __func__, ctxid); + rc = -EPERM; + goto err; + } + + file = cfg->ops->get_fd(ctx, &cfg->cxl_fops, &fd); + if (unlikely(fd < 0)) { + rc = -ENODEV; + dev_err(dev, "%s: Could not get file descriptor\n", __func__); + goto err; + } + + /* Translate read/write O_* flags from fcntl.h to AFU permission bits */ + perms = SISL_RHT_PERM(attach->hdr.flags + 1); + + /* Context mutex is locked upon return */ + init_context(ctxi, cfg, ctx, ctxid, file, perms, irqs); + + rc = afu_attach(cfg, ctxi); + if (unlikely(rc)) { + dev_err(dev, "%s: Could not attach AFU rc %d\n", __func__, rc); + goto err; + } + + /* + * No error paths after this point. Once the fd is installed it's + * visible to user space and can't be undone safely on this thread. + * There is no need to worry about a deadlock here because no one + * knows about us yet; we can be the only one holding our mutex. + */ + list_add(&lun_access->list, &ctxi->luns); + mutex_lock(&cfg->ctx_tbl_list_mutex); + mutex_lock(&ctxi->mutex); + cfg->ctx_tbl[ctxid] = ctxi; + mutex_unlock(&cfg->ctx_tbl_list_mutex); + fd_install(fd, file); + +out_attach: + if (fd != -1) + flags |= DK_CXLFLASH_APP_CLOSE_ADAP_FD; + if (afu_is_sq_cmd_mode(afu)) + flags |= DK_CXLFLASH_CONTEXT_SQ_CMD_MODE; + + attach->hdr.return_flags = flags; + attach->context_id = ctxi->ctxid; + attach->block_size = gli->blk_len; + attach->mmio_size = sizeof(afu->afu_map->hosts[0].harea); + attach->last_lba = gli->max_lba; + attach->max_xfer = sdev->host->max_sectors * MAX_SECTOR_UNIT; + attach->max_xfer /= gli->blk_len; + +out: + attach->adap_fd = fd; + + if (ctxi) + put_context(ctxi); + + dev_dbg(dev, "%s: returning ctxid=%d fd=%d bs=%lld rc=%d llba=%lld\n", + __func__, ctxid, fd, attach->block_size, rc, attach->last_lba); + return rc; + +err: + /* Cleanup CXL context; okay to 'stop' even if it was not started */ + if (!IS_ERR_OR_NULL(ctx)) { + cfg->ops->stop_context(ctx); + cfg->ops->release_context(ctx); + ctx = NULL; + } + + /* + * Here, we're overriding the fops with a dummy all-NULL fops because + * fput() calls the release fop, which will cause us to mistakenly + * call into the CXL code. Rather than try to add yet more complexity + * to that routine (cxlflash_cxl_release) we should try to fix the + * issue here. + */ + if (fd > 0) { + file->f_op = &null_fops; + fput(file); + put_unused_fd(fd); + fd = -1; + file = NULL; + } + + /* Cleanup our context */ + if (ctxi) { + destroy_context(cfg, ctxi); + ctxi = NULL; + } + + kfree(lun_access); + scsi_device_put(sdev); + goto out; +} + +/** + * recover_context() - recovers a context in error + * @cfg: Internal structure associated with the host. + * @ctxi: Context to release. + * @adap_fd: Adapter file descriptor associated with new/recovered context. + * + * Restablishes the state for a context-in-error. + * + * Return: 0 on success, -errno on failure + */ +static int recover_context(struct cxlflash_cfg *cfg, + struct ctx_info *ctxi, + int *adap_fd) +{ + struct device *dev = &cfg->dev->dev; + int rc = 0; + int fd = -1; + int ctxid = -1; + struct file *file; + void *ctx; + struct afu *afu = cfg->afu; + + ctx = cfg->ops->dev_context_init(cfg->dev, cfg->afu_cookie); + if (IS_ERR_OR_NULL(ctx)) { + dev_err(dev, "%s: Could not initialize context %p\n", + __func__, ctx); + rc = -ENODEV; + goto out; + } + + rc = cfg->ops->start_work(ctx, ctxi->irqs); + if (unlikely(rc)) { + dev_dbg(dev, "%s: Could not start context rc=%d\n", + __func__, rc); + goto err1; + } + + ctxid = cfg->ops->process_element(ctx); + if (unlikely((ctxid >= MAX_CONTEXT) || (ctxid < 0))) { + dev_err(dev, "%s: ctxid=%d invalid\n", __func__, ctxid); + rc = -EPERM; + goto err2; + } + + file = cfg->ops->get_fd(ctx, &cfg->cxl_fops, &fd); + if (unlikely(fd < 0)) { + rc = -ENODEV; + dev_err(dev, "%s: Could not get file descriptor\n", __func__); + goto err2; + } + + /* Update with new MMIO area based on updated context id */ + ctxi->ctrl_map = &afu->afu_map->ctrls[ctxid].ctrl; + + rc = afu_attach(cfg, ctxi); + if (rc) { + dev_err(dev, "%s: Could not attach AFU rc %d\n", __func__, rc); + goto err3; + } + + /* + * No error paths after this point. Once the fd is installed it's + * visible to user space and can't be undone safely on this thread. + */ + ctxi->ctxid = ENCODE_CTXID(ctxi, ctxid); + ctxi->ctx = ctx; + ctxi->file = file; + + /* + * Put context back in table (note the reinit of the context list); + * we must first drop the context's mutex and then acquire it in + * order with the table/list mutex to avoid a deadlock - safe to do + * here because no one can find us at this moment in time. + */ + mutex_unlock(&ctxi->mutex); + mutex_lock(&cfg->ctx_tbl_list_mutex); + mutex_lock(&ctxi->mutex); + list_del_init(&ctxi->list); + cfg->ctx_tbl[ctxid] = ctxi; + mutex_unlock(&cfg->ctx_tbl_list_mutex); + fd_install(fd, file); + *adap_fd = fd; +out: + dev_dbg(dev, "%s: returning ctxid=%d fd=%d rc=%d\n", + __func__, ctxid, fd, rc); + return rc; + +err3: + fput(file); + put_unused_fd(fd); +err2: + cfg->ops->stop_context(ctx); +err1: + cfg->ops->release_context(ctx); + goto out; +} + +/** + * cxlflash_afu_recover() - initiates AFU recovery + * @sdev: SCSI device associated with LUN. + * @recover: Recover ioctl data structure. + * + * Only a single recovery is allowed at a time to avoid exhausting CXL + * resources (leading to recovery failure) in the event that we're up + * against the maximum number of contexts limit. For similar reasons, + * a context recovery is retried if there are multiple recoveries taking + * place at the same time and the failure was due to CXL services being + * unable to keep up. + * + * As this routine is called on ioctl context, it holds the ioctl r/w + * semaphore that is used to drain ioctls in recovery scenarios. The + * implementation to achieve the pacing described above (a local mutex) + * requires that the ioctl r/w semaphore be dropped and reacquired to + * avoid a 3-way deadlock when multiple process recoveries operate in + * parallel. + * + * Because a user can detect an error condition before the kernel, it is + * quite possible for this routine to act as the kernel's EEH detection + * source (MMIO read of mbox_r). Because of this, there is a window of + * time where an EEH might have been detected but not yet 'serviced' + * (callback invoked, causing the device to enter reset state). To avoid + * looping in this routine during that window, a 1 second sleep is in place + * between the time the MMIO failure is detected and the time a wait on the + * reset wait queue is attempted via check_state(). + * + * Return: 0 on success, -errno on failure + */ +static int cxlflash_afu_recover(struct scsi_device *sdev, + struct dk_cxlflash_recover_afu *recover) +{ + struct cxlflash_cfg *cfg = shost_priv(sdev->host); + struct device *dev = &cfg->dev->dev; + struct llun_info *lli = sdev->hostdata; + struct afu *afu = cfg->afu; + struct ctx_info *ctxi = NULL; + struct mutex *mutex = &cfg->ctx_recovery_mutex; + struct hwq *hwq = get_hwq(afu, PRIMARY_HWQ); + u64 flags; + u64 ctxid = DECODE_CTXID(recover->context_id), + rctxid = recover->context_id; + long reg; + bool locked = true; + int lretry = 20; /* up to 2 seconds */ + int new_adap_fd = -1; + int rc = 0; + + atomic_inc(&cfg->recovery_threads); + up_read(&cfg->ioctl_rwsem); + rc = mutex_lock_interruptible(mutex); + down_read(&cfg->ioctl_rwsem); + if (rc) { + locked = false; + goto out; + } + + rc = check_state(cfg); + if (rc) { + dev_err(dev, "%s: Failed state rc=%d\n", __func__, rc); + rc = -ENODEV; + goto out; + } + + dev_dbg(dev, "%s: reason=%016llx rctxid=%016llx\n", + __func__, recover->reason, rctxid); + +retry: + /* Ensure that this process is attached to the context */ + ctxi = get_context(cfg, rctxid, lli, CTX_CTRL_ERR_FALLBACK); + if (unlikely(!ctxi)) { + dev_dbg(dev, "%s: Bad context ctxid=%llu\n", __func__, ctxid); + rc = -EINVAL; + goto out; + } + + if (ctxi->err_recovery_active) { +retry_recover: + rc = recover_context(cfg, ctxi, &new_adap_fd); + if (unlikely(rc)) { + dev_err(dev, "%s: Recovery failed ctxid=%llu rc=%d\n", + __func__, ctxid, rc); + if ((rc == -ENODEV) && + ((atomic_read(&cfg->recovery_threads) > 1) || + (lretry--))) { + dev_dbg(dev, "%s: Going to try again\n", + __func__); + mutex_unlock(mutex); + msleep(100); + rc = mutex_lock_interruptible(mutex); + if (rc) { + locked = false; + goto out; + } + goto retry_recover; + } + + goto out; + } + + ctxi->err_recovery_active = false; + + flags = DK_CXLFLASH_APP_CLOSE_ADAP_FD | + DK_CXLFLASH_RECOVER_AFU_CONTEXT_RESET; + if (afu_is_sq_cmd_mode(afu)) + flags |= DK_CXLFLASH_CONTEXT_SQ_CMD_MODE; + + recover->hdr.return_flags = flags; + recover->context_id = ctxi->ctxid; + recover->adap_fd = new_adap_fd; + recover->mmio_size = sizeof(afu->afu_map->hosts[0].harea); + goto out; + } + + /* Test if in error state */ + reg = readq_be(&hwq->ctrl_map->mbox_r); + if (reg == -1) { + dev_dbg(dev, "%s: MMIO fail, wait for recovery.\n", __func__); + + /* + * Before checking the state, put back the context obtained with + * get_context() as it is no longer needed and sleep for a short + * period of time (see prolog notes). + */ + put_context(ctxi); + ctxi = NULL; + ssleep(1); + rc = check_state(cfg); + if (unlikely(rc)) + goto out; + goto retry; + } + + dev_dbg(dev, "%s: MMIO working, no recovery required\n", __func__); +out: + if (likely(ctxi)) + put_context(ctxi); + if (locked) + mutex_unlock(mutex); + atomic_dec_if_positive(&cfg->recovery_threads); + return rc; +} + +/** + * process_sense() - evaluates and processes sense data + * @sdev: SCSI device associated with LUN. + * @verify: Verify ioctl data structure. + * + * Return: 0 on success, -errno on failure + */ +static int process_sense(struct scsi_device *sdev, + struct dk_cxlflash_verify *verify) +{ + struct cxlflash_cfg *cfg = shost_priv(sdev->host); + struct device *dev = &cfg->dev->dev; + struct llun_info *lli = sdev->hostdata; + struct glun_info *gli = lli->parent; + u64 prev_lba = gli->max_lba; + struct scsi_sense_hdr sshdr = { 0 }; + int rc = 0; + + rc = scsi_normalize_sense((const u8 *)&verify->sense_data, + DK_CXLFLASH_VERIFY_SENSE_LEN, &sshdr); + if (!rc) { + dev_err(dev, "%s: Failed to normalize sense data\n", __func__); + rc = -EINVAL; + goto out; + } + + switch (sshdr.sense_key) { + case NO_SENSE: + case RECOVERED_ERROR: + case NOT_READY: + break; + case UNIT_ATTENTION: + switch (sshdr.asc) { + case 0x29: /* Power on Reset or Device Reset */ + fallthrough; + case 0x2A: /* Device settings/capacity changed */ + rc = read_cap16(sdev, lli); + if (rc) { + rc = -ENODEV; + break; + } + if (prev_lba != gli->max_lba) + dev_dbg(dev, "%s: Capacity changed old=%lld " + "new=%lld\n", __func__, prev_lba, + gli->max_lba); + break; + case 0x3F: /* Report LUNs changed, Rescan. */ + scsi_scan_host(cfg->host); + break; + default: + rc = -EIO; + break; + } + break; + default: + rc = -EIO; + break; + } +out: + dev_dbg(dev, "%s: sense_key %x asc %x ascq %x rc %d\n", __func__, + sshdr.sense_key, sshdr.asc, sshdr.ascq, rc); + return rc; +} + +/** + * cxlflash_disk_verify() - verifies a LUN is the same and handle size changes + * @sdev: SCSI device associated with LUN. + * @verify: Verify ioctl data structure. + * + * Return: 0 on success, -errno on failure + */ +static int cxlflash_disk_verify(struct scsi_device *sdev, + struct dk_cxlflash_verify *verify) +{ + int rc = 0; + struct ctx_info *ctxi = NULL; + struct cxlflash_cfg *cfg = shost_priv(sdev->host); + struct device *dev = &cfg->dev->dev; + struct llun_info *lli = sdev->hostdata; + struct glun_info *gli = lli->parent; + struct sisl_rht_entry *rhte = NULL; + res_hndl_t rhndl = verify->rsrc_handle; + u64 ctxid = DECODE_CTXID(verify->context_id), + rctxid = verify->context_id; + u64 last_lba = 0; + + dev_dbg(dev, "%s: ctxid=%llu rhndl=%016llx, hint=%016llx, " + "flags=%016llx\n", __func__, ctxid, verify->rsrc_handle, + verify->hint, verify->hdr.flags); + + ctxi = get_context(cfg, rctxid, lli, 0); + if (unlikely(!ctxi)) { + dev_dbg(dev, "%s: Bad context ctxid=%llu\n", __func__, ctxid); + rc = -EINVAL; + goto out; + } + + rhte = get_rhte(ctxi, rhndl, lli); + if (unlikely(!rhte)) { + dev_dbg(dev, "%s: Bad resource handle rhndl=%d\n", + __func__, rhndl); + rc = -EINVAL; + goto out; + } + + /* + * Look at the hint/sense to see if it requires us to redrive + * inquiry (i.e. the Unit attention is due to the WWN changing). + */ + if (verify->hint & DK_CXLFLASH_VERIFY_HINT_SENSE) { + /* Can't hold mutex across process_sense/read_cap16, + * since we could have an intervening EEH event. + */ + ctxi->unavail = true; + mutex_unlock(&ctxi->mutex); + rc = process_sense(sdev, verify); + if (unlikely(rc)) { + dev_err(dev, "%s: Failed to validate sense data (%d)\n", + __func__, rc); + mutex_lock(&ctxi->mutex); + ctxi->unavail = false; + goto out; + } + mutex_lock(&ctxi->mutex); + ctxi->unavail = false; + } + + switch (gli->mode) { + case MODE_PHYSICAL: + last_lba = gli->max_lba; + break; + case MODE_VIRTUAL: + /* Cast lxt_cnt to u64 for multiply to be treated as 64bit op */ + last_lba = ((u64)rhte->lxt_cnt * MC_CHUNK_SIZE * gli->blk_len); + last_lba /= CXLFLASH_BLOCK_SIZE; + last_lba--; + break; + default: + WARN(1, "Unsupported LUN mode!"); + } + + verify->last_lba = last_lba; + +out: + if (likely(ctxi)) + put_context(ctxi); + dev_dbg(dev, "%s: returning rc=%d llba=%llx\n", + __func__, rc, verify->last_lba); + return rc; +} + +/** + * decode_ioctl() - translates an encoded ioctl to an easily identifiable string + * @cmd: The ioctl command to decode. + * + * Return: A string identifying the decoded ioctl. + */ +static char *decode_ioctl(unsigned int cmd) +{ + switch (cmd) { + case DK_CXLFLASH_ATTACH: + return __stringify_1(DK_CXLFLASH_ATTACH); + case DK_CXLFLASH_USER_DIRECT: + return __stringify_1(DK_CXLFLASH_USER_DIRECT); + case DK_CXLFLASH_USER_VIRTUAL: + return __stringify_1(DK_CXLFLASH_USER_VIRTUAL); + case DK_CXLFLASH_VLUN_RESIZE: + return __stringify_1(DK_CXLFLASH_VLUN_RESIZE); + case DK_CXLFLASH_RELEASE: + return __stringify_1(DK_CXLFLASH_RELEASE); + case DK_CXLFLASH_DETACH: + return __stringify_1(DK_CXLFLASH_DETACH); + case DK_CXLFLASH_VERIFY: + return __stringify_1(DK_CXLFLASH_VERIFY); + case DK_CXLFLASH_VLUN_CLONE: + return __stringify_1(DK_CXLFLASH_VLUN_CLONE); + case DK_CXLFLASH_RECOVER_AFU: + return __stringify_1(DK_CXLFLASH_RECOVER_AFU); + case DK_CXLFLASH_MANAGE_LUN: + return __stringify_1(DK_CXLFLASH_MANAGE_LUN); + } + + return "UNKNOWN"; +} + +/** + * cxlflash_disk_direct_open() - opens a direct (physical) disk + * @sdev: SCSI device associated with LUN. + * @arg: UDirect ioctl data structure. + * + * On successful return, the user is informed of the resource handle + * to be used to identify the direct lun and the size (in blocks) of + * the direct lun in last LBA format. + * + * Return: 0 on success, -errno on failure + */ +static int cxlflash_disk_direct_open(struct scsi_device *sdev, void *arg) +{ + struct cxlflash_cfg *cfg = shost_priv(sdev->host); + struct device *dev = &cfg->dev->dev; + struct afu *afu = cfg->afu; + struct llun_info *lli = sdev->hostdata; + struct glun_info *gli = lli->parent; + struct dk_cxlflash_release rel = { { 0 }, 0 }; + + struct dk_cxlflash_udirect *pphys = (struct dk_cxlflash_udirect *)arg; + + u64 ctxid = DECODE_CTXID(pphys->context_id), + rctxid = pphys->context_id; + u64 lun_size = 0; + u64 last_lba = 0; + u64 rsrc_handle = -1; + u32 port = CHAN2PORTMASK(sdev->channel); + + int rc = 0; + + struct ctx_info *ctxi = NULL; + struct sisl_rht_entry *rhte = NULL; + + dev_dbg(dev, "%s: ctxid=%llu ls=%llu\n", __func__, ctxid, lun_size); + + rc = cxlflash_lun_attach(gli, MODE_PHYSICAL, false); + if (unlikely(rc)) { + dev_dbg(dev, "%s: Failed attach to LUN (PHYSICAL)\n", __func__); + goto out; + } + + ctxi = get_context(cfg, rctxid, lli, 0); + if (unlikely(!ctxi)) { + dev_dbg(dev, "%s: Bad context ctxid=%llu\n", __func__, ctxid); + rc = -EINVAL; + goto err1; + } + + rhte = rhte_checkout(ctxi, lli); + if (unlikely(!rhte)) { + dev_dbg(dev, "%s: Too many opens ctxid=%lld\n", + __func__, ctxid); + rc = -EMFILE; /* too many opens */ + goto err1; + } + + rsrc_handle = (rhte - ctxi->rht_start); + + rht_format1(rhte, lli->lun_id[sdev->channel], ctxi->rht_perms, port); + + last_lba = gli->max_lba; + pphys->hdr.return_flags = 0; + pphys->last_lba = last_lba; + pphys->rsrc_handle = rsrc_handle; + + rc = cxlflash_afu_sync(afu, ctxid, rsrc_handle, AFU_LW_SYNC); + if (unlikely(rc)) { + dev_dbg(dev, "%s: AFU sync failed rc=%d\n", __func__, rc); + goto err2; + } + +out: + if (likely(ctxi)) + put_context(ctxi); + dev_dbg(dev, "%s: returning handle=%llu rc=%d llba=%llu\n", + __func__, rsrc_handle, rc, last_lba); + return rc; + +err2: + marshal_udir_to_rele(pphys, &rel); + _cxlflash_disk_release(sdev, ctxi, &rel); + goto out; +err1: + cxlflash_lun_detach(gli); + goto out; +} + +/** + * ioctl_common() - common IOCTL handler for driver + * @sdev: SCSI device associated with LUN. + * @cmd: IOCTL command. + * + * Handles common fencing operations that are valid for multiple ioctls. Always + * allow through ioctls that are cleanup oriented in nature, even when operating + * in a failed/terminating state. + * + * Return: 0 on success, -errno on failure + */ +static int ioctl_common(struct scsi_device *sdev, unsigned int cmd) +{ + struct cxlflash_cfg *cfg = shost_priv(sdev->host); + struct device *dev = &cfg->dev->dev; + struct llun_info *lli = sdev->hostdata; + int rc = 0; + + if (unlikely(!lli)) { + dev_dbg(dev, "%s: Unknown LUN\n", __func__); + rc = -EINVAL; + goto out; + } + + rc = check_state(cfg); + if (unlikely(rc) && (cfg->state == STATE_FAILTERM)) { + switch (cmd) { + case DK_CXLFLASH_VLUN_RESIZE: + case DK_CXLFLASH_RELEASE: + case DK_CXLFLASH_DETACH: + dev_dbg(dev, "%s: Command override rc=%d\n", + __func__, rc); + rc = 0; + break; + } + } +out: + return rc; +} + +/** + * cxlflash_ioctl() - IOCTL handler for driver + * @sdev: SCSI device associated with LUN. + * @cmd: IOCTL command. + * @arg: Userspace ioctl data structure. + * + * A read/write semaphore is used to implement a 'drain' of currently + * running ioctls. The read semaphore is taken at the beginning of each + * ioctl thread and released upon concluding execution. Additionally the + * semaphore should be released and then reacquired in any ioctl execution + * path which will wait for an event to occur that is outside the scope of + * the ioctl (i.e. an adapter reset). To drain the ioctls currently running, + * a thread simply needs to acquire the write semaphore. + * + * Return: 0 on success, -errno on failure + */ +int cxlflash_ioctl(struct scsi_device *sdev, unsigned int cmd, void __user *arg) +{ + typedef int (*sioctl) (struct scsi_device *, void *); + + struct cxlflash_cfg *cfg = shost_priv(sdev->host); + struct device *dev = &cfg->dev->dev; + struct afu *afu = cfg->afu; + struct dk_cxlflash_hdr *hdr; + char buf[sizeof(union cxlflash_ioctls)]; + size_t size = 0; + bool known_ioctl = false; + int idx; + int rc = 0; + struct Scsi_Host *shost = sdev->host; + sioctl do_ioctl = NULL; + + static const struct { + size_t size; + sioctl ioctl; + } ioctl_tbl[] = { /* NOTE: order matters here */ + {sizeof(struct dk_cxlflash_attach), (sioctl)cxlflash_disk_attach}, + {sizeof(struct dk_cxlflash_udirect), cxlflash_disk_direct_open}, + {sizeof(struct dk_cxlflash_release), (sioctl)cxlflash_disk_release}, + {sizeof(struct dk_cxlflash_detach), (sioctl)cxlflash_disk_detach}, + {sizeof(struct dk_cxlflash_verify), (sioctl)cxlflash_disk_verify}, + {sizeof(struct dk_cxlflash_recover_afu), (sioctl)cxlflash_afu_recover}, + {sizeof(struct dk_cxlflash_manage_lun), (sioctl)cxlflash_manage_lun}, + {sizeof(struct dk_cxlflash_uvirtual), cxlflash_disk_virtual_open}, + {sizeof(struct dk_cxlflash_resize), (sioctl)cxlflash_vlun_resize}, + {sizeof(struct dk_cxlflash_clone), (sioctl)cxlflash_disk_clone}, + }; + + /* Hold read semaphore so we can drain if needed */ + down_read(&cfg->ioctl_rwsem); + + /* Restrict command set to physical support only for internal LUN */ + if (afu->internal_lun) + switch (cmd) { + case DK_CXLFLASH_RELEASE: + case DK_CXLFLASH_USER_VIRTUAL: + case DK_CXLFLASH_VLUN_RESIZE: + case DK_CXLFLASH_VLUN_CLONE: + dev_dbg(dev, "%s: %s not supported for lun_mode=%d\n", + __func__, decode_ioctl(cmd), afu->internal_lun); + rc = -EINVAL; + goto cxlflash_ioctl_exit; + } + + switch (cmd) { + case DK_CXLFLASH_ATTACH: + case DK_CXLFLASH_USER_DIRECT: + case DK_CXLFLASH_RELEASE: + case DK_CXLFLASH_DETACH: + case DK_CXLFLASH_VERIFY: + case DK_CXLFLASH_RECOVER_AFU: + case DK_CXLFLASH_USER_VIRTUAL: + case DK_CXLFLASH_VLUN_RESIZE: + case DK_CXLFLASH_VLUN_CLONE: + dev_dbg(dev, "%s: %s (%08X) on dev(%d/%d/%d/%llu)\n", + __func__, decode_ioctl(cmd), cmd, shost->host_no, + sdev->channel, sdev->id, sdev->lun); + rc = ioctl_common(sdev, cmd); + if (unlikely(rc)) + goto cxlflash_ioctl_exit; + + fallthrough; + + case DK_CXLFLASH_MANAGE_LUN: + known_ioctl = true; + idx = _IOC_NR(cmd) - _IOC_NR(DK_CXLFLASH_ATTACH); + size = ioctl_tbl[idx].size; + do_ioctl = ioctl_tbl[idx].ioctl; + + if (likely(do_ioctl)) + break; + + fallthrough; + default: + rc = -EINVAL; + goto cxlflash_ioctl_exit; + } + + if (unlikely(copy_from_user(&buf, arg, size))) { + dev_err(dev, "%s: copy_from_user() fail size=%lu cmd=%u (%s) arg=%p\n", + __func__, size, cmd, decode_ioctl(cmd), arg); + rc = -EFAULT; + goto cxlflash_ioctl_exit; + } + + hdr = (struct dk_cxlflash_hdr *)&buf; + if (hdr->version != DK_CXLFLASH_VERSION_0) { + dev_dbg(dev, "%s: Version %u not supported for %s\n", + __func__, hdr->version, decode_ioctl(cmd)); + rc = -EINVAL; + goto cxlflash_ioctl_exit; + } + + if (hdr->rsvd[0] || hdr->rsvd[1] || hdr->rsvd[2] || hdr->return_flags) { + dev_dbg(dev, "%s: Reserved/rflags populated\n", __func__); + rc = -EINVAL; + goto cxlflash_ioctl_exit; + } + + rc = do_ioctl(sdev, (void *)&buf); + if (likely(!rc)) + if (unlikely(copy_to_user(arg, &buf, size))) { + dev_err(dev, "%s: copy_to_user() fail size=%lu cmd=%u (%s) arg=%p\n", + __func__, size, cmd, decode_ioctl(cmd), arg); + rc = -EFAULT; + } + + /* fall through to exit */ + +cxlflash_ioctl_exit: + up_read(&cfg->ioctl_rwsem); + if (unlikely(rc && known_ioctl)) + dev_err(dev, "%s: ioctl %s (%08X) on dev(%d/%d/%d/%llu) " + "returned rc %d\n", __func__, + decode_ioctl(cmd), cmd, shost->host_no, + sdev->channel, sdev->id, sdev->lun, rc); + else + dev_dbg(dev, "%s: ioctl %s (%08X) on dev(%d/%d/%d/%llu) " + "returned rc %d\n", __func__, decode_ioctl(cmd), + cmd, shost->host_no, sdev->channel, sdev->id, + sdev->lun, rc); + return rc; +} |