diff options
Diffstat (limited to 'drivers/scsi/cxlflash/vlun.c')
| -rw-r--r-- | drivers/scsi/cxlflash/vlun.c | 1337 |
1 files changed, 1337 insertions, 0 deletions
diff --git a/drivers/scsi/cxlflash/vlun.c b/drivers/scsi/cxlflash/vlun.c new file mode 100644 index 0000000000..cbd5a648a1 --- /dev/null +++ b/drivers/scsi/cxlflash/vlun.c @@ -0,0 +1,1337 @@ +// 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/interrupt.h> +#include <linux/pci.h> +#include <linux/syscalls.h> +#include <asm/unaligned.h> +#include <asm/bitsperlong.h> + +#include <scsi/scsi_cmnd.h> +#include <scsi/scsi_host.h> +#include <uapi/scsi/cxlflash_ioctl.h> + +#include "sislite.h" +#include "common.h" +#include "vlun.h" +#include "superpipe.h" + +/** + * marshal_virt_to_resize() - translate uvirtual to resize structure + * @virt: Source structure from which to translate/copy. + * @resize: Destination structure for the translate/copy. + */ +static void marshal_virt_to_resize(struct dk_cxlflash_uvirtual *virt, + struct dk_cxlflash_resize *resize) +{ + resize->hdr = virt->hdr; + resize->context_id = virt->context_id; + resize->rsrc_handle = virt->rsrc_handle; + resize->req_size = virt->lun_size; + resize->last_lba = virt->last_lba; +} + +/** + * marshal_clone_to_rele() - translate clone to release structure + * @clone: Source structure from which to translate/copy. + * @release: Destination structure for the translate/copy. + */ +static void marshal_clone_to_rele(struct dk_cxlflash_clone *clone, + struct dk_cxlflash_release *release) +{ + release->hdr = clone->hdr; + release->context_id = clone->context_id_dst; +} + +/** + * ba_init() - initializes a block allocator + * @ba_lun: Block allocator to initialize. + * + * Return: 0 on success, -errno on failure + */ +static int ba_init(struct ba_lun *ba_lun) +{ + struct ba_lun_info *bali = NULL; + int lun_size_au = 0, i = 0; + int last_word_underflow = 0; + u64 *lam; + + pr_debug("%s: Initializing LUN: lun_id=%016llx " + "ba_lun->lsize=%lx ba_lun->au_size=%lX\n", + __func__, ba_lun->lun_id, ba_lun->lsize, ba_lun->au_size); + + /* Calculate bit map size */ + lun_size_au = ba_lun->lsize / ba_lun->au_size; + if (lun_size_au == 0) { + pr_debug("%s: Requested LUN size of 0!\n", __func__); + return -EINVAL; + } + + /* Allocate lun information container */ + bali = kzalloc(sizeof(struct ba_lun_info), GFP_KERNEL); + if (unlikely(!bali)) { + pr_err("%s: Failed to allocate lun_info lun_id=%016llx\n", + __func__, ba_lun->lun_id); + return -ENOMEM; + } + + bali->total_aus = lun_size_au; + bali->lun_bmap_size = lun_size_au / BITS_PER_LONG; + + if (lun_size_au % BITS_PER_LONG) + bali->lun_bmap_size++; + + /* Allocate bitmap space */ + bali->lun_alloc_map = kzalloc((bali->lun_bmap_size * sizeof(u64)), + GFP_KERNEL); + if (unlikely(!bali->lun_alloc_map)) { + pr_err("%s: Failed to allocate lun allocation map: " + "lun_id=%016llx\n", __func__, ba_lun->lun_id); + kfree(bali); + return -ENOMEM; + } + + /* Initialize the bit map size and set all bits to '1' */ + bali->free_aun_cnt = lun_size_au; + + for (i = 0; i < bali->lun_bmap_size; i++) + bali->lun_alloc_map[i] = 0xFFFFFFFFFFFFFFFFULL; + + /* If the last word not fully utilized, mark extra bits as allocated */ + last_word_underflow = (bali->lun_bmap_size * BITS_PER_LONG); + last_word_underflow -= bali->free_aun_cnt; + if (last_word_underflow > 0) { + lam = &bali->lun_alloc_map[bali->lun_bmap_size - 1]; + for (i = (HIBIT - last_word_underflow + 1); + i < BITS_PER_LONG; + i++) + clear_bit(i, (ulong *)lam); + } + + /* Initialize high elevator index, low/curr already at 0 from kzalloc */ + bali->free_high_idx = bali->lun_bmap_size; + + /* Allocate clone map */ + bali->aun_clone_map = kzalloc((bali->total_aus * sizeof(u8)), + GFP_KERNEL); + if (unlikely(!bali->aun_clone_map)) { + pr_err("%s: Failed to allocate clone map: lun_id=%016llx\n", + __func__, ba_lun->lun_id); + kfree(bali->lun_alloc_map); + kfree(bali); + return -ENOMEM; + } + + /* Pass the allocated LUN info as a handle to the user */ + ba_lun->ba_lun_handle = bali; + + pr_debug("%s: Successfully initialized the LUN: " + "lun_id=%016llx bitmap size=%x, free_aun_cnt=%llx\n", + __func__, ba_lun->lun_id, bali->lun_bmap_size, + bali->free_aun_cnt); + return 0; +} + +/** + * find_free_range() - locates a free bit within the block allocator + * @low: First word in block allocator to start search. + * @high: Last word in block allocator to search. + * @bali: LUN information structure owning the block allocator to search. + * @bit_word: Passes back the word in the block allocator owning the free bit. + * + * Return: The bit position within the passed back word, -1 on failure + */ +static int find_free_range(u32 low, + u32 high, + struct ba_lun_info *bali, int *bit_word) +{ + int i; + u64 bit_pos = -1; + ulong *lam, num_bits; + + for (i = low; i < high; i++) + if (bali->lun_alloc_map[i] != 0) { + lam = (ulong *)&bali->lun_alloc_map[i]; + num_bits = (sizeof(*lam) * BITS_PER_BYTE); + bit_pos = find_first_bit(lam, num_bits); + + pr_devel("%s: Found free bit %llu in LUN " + "map entry %016llx at bitmap index = %d\n", + __func__, bit_pos, bali->lun_alloc_map[i], i); + + *bit_word = i; + bali->free_aun_cnt--; + clear_bit(bit_pos, lam); + break; + } + + return bit_pos; +} + +/** + * ba_alloc() - allocates a block from the block allocator + * @ba_lun: Block allocator from which to allocate a block. + * + * Return: The allocated block, -1 on failure + */ +static u64 ba_alloc(struct ba_lun *ba_lun) +{ + u64 bit_pos = -1; + int bit_word = 0; + struct ba_lun_info *bali = NULL; + + bali = ba_lun->ba_lun_handle; + + pr_debug("%s: Received block allocation request: " + "lun_id=%016llx free_aun_cnt=%llx\n", + __func__, ba_lun->lun_id, bali->free_aun_cnt); + + if (bali->free_aun_cnt == 0) { + pr_debug("%s: No space left on LUN: lun_id=%016llx\n", + __func__, ba_lun->lun_id); + return -1ULL; + } + + /* Search to find a free entry, curr->high then low->curr */ + bit_pos = find_free_range(bali->free_curr_idx, + bali->free_high_idx, bali, &bit_word); + if (bit_pos == -1) { + bit_pos = find_free_range(bali->free_low_idx, + bali->free_curr_idx, + bali, &bit_word); + if (bit_pos == -1) { + pr_debug("%s: Could not find an allocation unit on LUN:" + " lun_id=%016llx\n", __func__, ba_lun->lun_id); + return -1ULL; + } + } + + /* Update the free_curr_idx */ + if (bit_pos == HIBIT) + bali->free_curr_idx = bit_word + 1; + else + bali->free_curr_idx = bit_word; + + pr_debug("%s: Allocating AU number=%llx lun_id=%016llx " + "free_aun_cnt=%llx\n", __func__, + ((bit_word * BITS_PER_LONG) + bit_pos), ba_lun->lun_id, + bali->free_aun_cnt); + + return (u64) ((bit_word * BITS_PER_LONG) + bit_pos); +} + +/** + * validate_alloc() - validates the specified block has been allocated + * @bali: LUN info owning the block allocator. + * @aun: Block to validate. + * + * Return: 0 on success, -1 on failure + */ +static int validate_alloc(struct ba_lun_info *bali, u64 aun) +{ + int idx = 0, bit_pos = 0; + + idx = aun / BITS_PER_LONG; + bit_pos = aun % BITS_PER_LONG; + + if (test_bit(bit_pos, (ulong *)&bali->lun_alloc_map[idx])) + return -1; + + return 0; +} + +/** + * ba_free() - frees a block from the block allocator + * @ba_lun: Block allocator from which to allocate a block. + * @to_free: Block to free. + * + * Return: 0 on success, -1 on failure + */ +static int ba_free(struct ba_lun *ba_lun, u64 to_free) +{ + int idx = 0, bit_pos = 0; + struct ba_lun_info *bali = NULL; + + bali = ba_lun->ba_lun_handle; + + if (validate_alloc(bali, to_free)) { + pr_debug("%s: AUN %llx is not allocated on lun_id=%016llx\n", + __func__, to_free, ba_lun->lun_id); + return -1; + } + + pr_debug("%s: Received a request to free AU=%llx lun_id=%016llx " + "free_aun_cnt=%llx\n", __func__, to_free, ba_lun->lun_id, + bali->free_aun_cnt); + + if (bali->aun_clone_map[to_free] > 0) { + pr_debug("%s: AUN %llx lun_id=%016llx cloned. Clone count=%x\n", + __func__, to_free, ba_lun->lun_id, + bali->aun_clone_map[to_free]); + bali->aun_clone_map[to_free]--; + return 0; + } + + idx = to_free / BITS_PER_LONG; + bit_pos = to_free % BITS_PER_LONG; + + set_bit(bit_pos, (ulong *)&bali->lun_alloc_map[idx]); + bali->free_aun_cnt++; + + if (idx < bali->free_low_idx) + bali->free_low_idx = idx; + else if (idx > bali->free_high_idx) + bali->free_high_idx = idx; + + pr_debug("%s: Successfully freed AU bit_pos=%x bit map index=%x " + "lun_id=%016llx free_aun_cnt=%llx\n", __func__, bit_pos, idx, + ba_lun->lun_id, bali->free_aun_cnt); + + return 0; +} + +/** + * ba_clone() - Clone a chunk of the block allocation table + * @ba_lun: Block allocator from which to allocate a block. + * @to_clone: Block to clone. + * + * Return: 0 on success, -1 on failure + */ +static int ba_clone(struct ba_lun *ba_lun, u64 to_clone) +{ + struct ba_lun_info *bali = ba_lun->ba_lun_handle; + + if (validate_alloc(bali, to_clone)) { + pr_debug("%s: AUN=%llx not allocated on lun_id=%016llx\n", + __func__, to_clone, ba_lun->lun_id); + return -1; + } + + pr_debug("%s: Received a request to clone AUN %llx on lun_id=%016llx\n", + __func__, to_clone, ba_lun->lun_id); + + if (bali->aun_clone_map[to_clone] == MAX_AUN_CLONE_CNT) { + pr_debug("%s: AUN %llx on lun_id=%016llx hit max clones already\n", + __func__, to_clone, ba_lun->lun_id); + return -1; + } + + bali->aun_clone_map[to_clone]++; + + return 0; +} + +/** + * ba_space() - returns the amount of free space left in the block allocator + * @ba_lun: Block allocator. + * + * Return: Amount of free space in block allocator + */ +static u64 ba_space(struct ba_lun *ba_lun) +{ + struct ba_lun_info *bali = ba_lun->ba_lun_handle; + + return bali->free_aun_cnt; +} + +/** + * cxlflash_ba_terminate() - frees resources associated with the block allocator + * @ba_lun: Block allocator. + * + * Safe to call in a partially allocated state. + */ +void cxlflash_ba_terminate(struct ba_lun *ba_lun) +{ + struct ba_lun_info *bali = ba_lun->ba_lun_handle; + + if (bali) { + kfree(bali->aun_clone_map); + kfree(bali->lun_alloc_map); + kfree(bali); + ba_lun->ba_lun_handle = NULL; + } +} + +/** + * init_vlun() - initializes a LUN for virtual use + * @lli: LUN information structure that owns the block allocator. + * + * Return: 0 on success, -errno on failure + */ +static int init_vlun(struct llun_info *lli) +{ + int rc = 0; + struct glun_info *gli = lli->parent; + struct blka *blka = &gli->blka; + + memset(blka, 0, sizeof(*blka)); + mutex_init(&blka->mutex); + + /* LUN IDs are unique per port, save the index instead */ + blka->ba_lun.lun_id = lli->lun_index; + blka->ba_lun.lsize = gli->max_lba + 1; + blka->ba_lun.lba_size = gli->blk_len; + + blka->ba_lun.au_size = MC_CHUNK_SIZE; + blka->nchunk = blka->ba_lun.lsize / MC_CHUNK_SIZE; + + rc = ba_init(&blka->ba_lun); + if (unlikely(rc)) + pr_debug("%s: cannot init block_alloc, rc=%d\n", __func__, rc); + + pr_debug("%s: returning rc=%d lli=%p\n", __func__, rc, lli); + return rc; +} + +/** + * write_same16() - sends a SCSI WRITE_SAME16 (0) command to specified LUN + * @sdev: SCSI device associated with LUN. + * @lba: Logical block address to start write same. + * @nblks: Number of logical blocks to write same. + * + * The SCSI WRITE_SAME16 can take quite a while to complete. Should an EEH occur + * while in scsi_execute_cmd(), 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_cmd() returns, reacquire the ioctl read semaphore and check the + * adapter state in case it changed while inside of scsi_execute_cmd(). 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 write_same16(struct scsi_device *sdev, + u64 lba, + u32 nblks) +{ + u8 *cmd_buf = NULL; + u8 *scsi_cmd = NULL; + int rc = 0; + int result = 0; + u64 offset = lba; + int left = nblks; + struct cxlflash_cfg *cfg = shost_priv(sdev->host); + struct device *dev = &cfg->dev->dev; + const u32 s = ilog2(sdev->sector_size) - 9; + const u32 to = sdev->request_queue->rq_timeout; + const u32 ws_limit = + sdev->request_queue->limits.max_write_zeroes_sectors >> s; + + 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; + } + + while (left > 0) { + + scsi_cmd[0] = WRITE_SAME_16; + scsi_cmd[1] = cfg->ws_unmap ? 0x8 : 0; + put_unaligned_be64(offset, &scsi_cmd[2]); + put_unaligned_be32(ws_limit < left ? ws_limit : left, + &scsi_cmd[10]); + + /* Drop the ioctl read semaphore across lengthy call */ + up_read(&cfg->ioctl_rwsem); + result = scsi_execute_cmd(sdev, scsi_cmd, REQ_OP_DRV_OUT, + cmd_buf, CMD_BUFSIZE, to, + CMD_RETRIES, 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) { + dev_err_ratelimited(dev, "%s: command failed for " + "offset=%lld result=%08x\n", + __func__, offset, result); + rc = -EIO; + goto out; + } + left -= ws_limit; + offset += ws_limit; + } + +out: + kfree(cmd_buf); + kfree(scsi_cmd); + dev_dbg(dev, "%s: returning rc=%d\n", __func__, rc); + return rc; +} + +/** + * grow_lxt() - expands the translation table associated with the specified RHTE + * @afu: AFU associated with the host. + * @sdev: SCSI device associated with LUN. + * @ctxid: Context ID of context owning the RHTE. + * @rhndl: Resource handle associated with the RHTE. + * @rhte: Resource handle entry (RHTE). + * @new_size: Number of translation entries associated with RHTE. + * + * By design, this routine employs a 'best attempt' allocation and will + * truncate the requested size down if there is not sufficient space in + * the block allocator to satisfy the request but there does exist some + * amount of space. The user is made aware of this by returning the size + * allocated. + * + * Return: 0 on success, -errno on failure + */ +static int grow_lxt(struct afu *afu, + struct scsi_device *sdev, + ctx_hndl_t ctxid, + res_hndl_t rhndl, + struct sisl_rht_entry *rhte, + u64 *new_size) +{ + struct cxlflash_cfg *cfg = shost_priv(sdev->host); + struct device *dev = &cfg->dev->dev; + struct sisl_lxt_entry *lxt = NULL, *lxt_old = NULL; + struct llun_info *lli = sdev->hostdata; + struct glun_info *gli = lli->parent; + struct blka *blka = &gli->blka; + u32 av_size; + u32 ngrps, ngrps_old; + u64 aun; /* chunk# allocated by block allocator */ + u64 delta = *new_size - rhte->lxt_cnt; + u64 my_new_size; + int i, rc = 0; + + /* + * Check what is available in the block allocator before re-allocating + * LXT array. This is done up front under the mutex which must not be + * released until after allocation is complete. + */ + mutex_lock(&blka->mutex); + av_size = ba_space(&blka->ba_lun); + if (unlikely(av_size <= 0)) { + dev_dbg(dev, "%s: ba_space error av_size=%d\n", + __func__, av_size); + mutex_unlock(&blka->mutex); + rc = -ENOSPC; + goto out; + } + + if (av_size < delta) + delta = av_size; + + lxt_old = rhte->lxt_start; + ngrps_old = LXT_NUM_GROUPS(rhte->lxt_cnt); + ngrps = LXT_NUM_GROUPS(rhte->lxt_cnt + delta); + + if (ngrps != ngrps_old) { + /* reallocate to fit new size */ + lxt = kzalloc((sizeof(*lxt) * LXT_GROUP_SIZE * ngrps), + GFP_KERNEL); + if (unlikely(!lxt)) { + mutex_unlock(&blka->mutex); + rc = -ENOMEM; + goto out; + } + + /* copy over all old entries */ + memcpy(lxt, lxt_old, (sizeof(*lxt) * rhte->lxt_cnt)); + } else + lxt = lxt_old; + + /* nothing can fail from now on */ + my_new_size = rhte->lxt_cnt + delta; + + /* add new entries to the end */ + for (i = rhte->lxt_cnt; i < my_new_size; i++) { + /* + * Due to the earlier check of available space, ba_alloc + * cannot fail here. If it did due to internal error, + * leave a rlba_base of -1u which will likely be a + * invalid LUN (too large). + */ + aun = ba_alloc(&blka->ba_lun); + if ((aun == -1ULL) || (aun >= blka->nchunk)) + dev_dbg(dev, "%s: ba_alloc error allocated chunk=%llu " + "max=%llu\n", __func__, aun, blka->nchunk - 1); + + /* select both ports, use r/w perms from RHT */ + lxt[i].rlba_base = ((aun << MC_CHUNK_SHIFT) | + (lli->lun_index << LXT_LUNIDX_SHIFT) | + (RHT_PERM_RW << LXT_PERM_SHIFT | + lli->port_sel)); + } + + mutex_unlock(&blka->mutex); + + /* + * The following sequence is prescribed in the SISlite spec + * for syncing up with the AFU when adding LXT entries. + */ + dma_wmb(); /* Make LXT updates are visible */ + + rhte->lxt_start = lxt; + dma_wmb(); /* Make RHT entry's LXT table update visible */ + + rhte->lxt_cnt = my_new_size; + dma_wmb(); /* Make RHT entry's LXT table size update visible */ + + rc = cxlflash_afu_sync(afu, ctxid, rhndl, AFU_LW_SYNC); + if (unlikely(rc)) + rc = -EAGAIN; + + /* free old lxt if reallocated */ + if (lxt != lxt_old) + kfree(lxt_old); + *new_size = my_new_size; +out: + dev_dbg(dev, "%s: returning rc=%d\n", __func__, rc); + return rc; +} + +/** + * shrink_lxt() - reduces translation table associated with the specified RHTE + * @afu: AFU associated with the host. + * @sdev: SCSI device associated with LUN. + * @rhndl: Resource handle associated with the RHTE. + * @rhte: Resource handle entry (RHTE). + * @ctxi: Context owning resources. + * @new_size: Number of translation entries associated with RHTE. + * + * Return: 0 on success, -errno on failure + */ +static int shrink_lxt(struct afu *afu, + struct scsi_device *sdev, + res_hndl_t rhndl, + struct sisl_rht_entry *rhte, + struct ctx_info *ctxi, + u64 *new_size) +{ + struct cxlflash_cfg *cfg = shost_priv(sdev->host); + struct device *dev = &cfg->dev->dev; + struct sisl_lxt_entry *lxt, *lxt_old; + struct llun_info *lli = sdev->hostdata; + struct glun_info *gli = lli->parent; + struct blka *blka = &gli->blka; + ctx_hndl_t ctxid = DECODE_CTXID(ctxi->ctxid); + bool needs_ws = ctxi->rht_needs_ws[rhndl]; + bool needs_sync = !ctxi->err_recovery_active; + u32 ngrps, ngrps_old; + u64 aun; /* chunk# allocated by block allocator */ + u64 delta = rhte->lxt_cnt - *new_size; + u64 my_new_size; + int i, rc = 0; + + lxt_old = rhte->lxt_start; + ngrps_old = LXT_NUM_GROUPS(rhte->lxt_cnt); + ngrps = LXT_NUM_GROUPS(rhte->lxt_cnt - delta); + + if (ngrps != ngrps_old) { + /* Reallocate to fit new size unless new size is 0 */ + if (ngrps) { + lxt = kzalloc((sizeof(*lxt) * LXT_GROUP_SIZE * ngrps), + GFP_KERNEL); + if (unlikely(!lxt)) { + rc = -ENOMEM; + goto out; + } + + /* Copy over old entries that will remain */ + memcpy(lxt, lxt_old, + (sizeof(*lxt) * (rhte->lxt_cnt - delta))); + } else + lxt = NULL; + } else + lxt = lxt_old; + + /* Nothing can fail from now on */ + my_new_size = rhte->lxt_cnt - delta; + + /* + * The following sequence is prescribed in the SISlite spec + * for syncing up with the AFU when removing LXT entries. + */ + rhte->lxt_cnt = my_new_size; + dma_wmb(); /* Make RHT entry's LXT table size update visible */ + + rhte->lxt_start = lxt; + dma_wmb(); /* Make RHT entry's LXT table update visible */ + + if (needs_sync) { + rc = cxlflash_afu_sync(afu, ctxid, rhndl, AFU_HW_SYNC); + if (unlikely(rc)) + rc = -EAGAIN; + } + + if (needs_ws) { + /* + * Mark the context as unavailable, so that we can release + * the mutex safely. + */ + ctxi->unavail = true; + mutex_unlock(&ctxi->mutex); + } + + /* Free LBAs allocated to freed chunks */ + mutex_lock(&blka->mutex); + for (i = delta - 1; i >= 0; i--) { + aun = lxt_old[my_new_size + i].rlba_base >> MC_CHUNK_SHIFT; + if (needs_ws) + write_same16(sdev, aun, MC_CHUNK_SIZE); + ba_free(&blka->ba_lun, aun); + } + mutex_unlock(&blka->mutex); + + if (needs_ws) { + /* Make the context visible again */ + mutex_lock(&ctxi->mutex); + ctxi->unavail = false; + } + + /* Free old lxt if reallocated */ + if (lxt != lxt_old) + kfree(lxt_old); + *new_size = my_new_size; +out: + dev_dbg(dev, "%s: returning rc=%d\n", __func__, rc); + return rc; +} + +/** + * _cxlflash_vlun_resize() - changes the size of a virtual LUN + * @sdev: SCSI device associated with LUN owning virtual LUN. + * @ctxi: Context owning resources. + * @resize: Resize ioctl data structure. + * + * On successful return, the user is informed of the new size (in blocks) + * of the virtual LUN in last LBA format. When the size of the virtual + * LUN is zero, the last LBA is reflected as -1. See comment in the + * prologue for _cxlflash_disk_release() regarding AFU syncs and contexts + * on the error recovery list. + * + * Return: 0 on success, -errno on failure + */ +int _cxlflash_vlun_resize(struct scsi_device *sdev, + struct ctx_info *ctxi, + struct dk_cxlflash_resize *resize) +{ + 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; + + res_hndl_t rhndl = resize->rsrc_handle; + u64 new_size; + u64 nsectors; + u64 ctxid = DECODE_CTXID(resize->context_id), + rctxid = resize->context_id; + + struct sisl_rht_entry *rhte; + + int rc = 0; + + /* + * The requested size (req_size) is always assumed to be in 4k blocks, + * so we have to convert it here from 4k to chunk size. + */ + nsectors = (resize->req_size * CXLFLASH_BLOCK_SIZE) / gli->blk_len; + new_size = DIV_ROUND_UP(nsectors, MC_CHUNK_SIZE); + + dev_dbg(dev, "%s: ctxid=%llu rhndl=%llu req_size=%llu new_size=%llu\n", + __func__, ctxid, resize->rsrc_handle, resize->req_size, + new_size); + + if (unlikely(gli->mode != MODE_VIRTUAL)) { + dev_dbg(dev, "%s: LUN mode does not support resize mode=%d\n", + __func__, gli->mode); + rc = -EINVAL; + goto out; + + } + + 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=%u\n", + __func__, rhndl); + rc = -EINVAL; + goto out; + } + + if (new_size > rhte->lxt_cnt) + rc = grow_lxt(afu, sdev, ctxid, rhndl, rhte, &new_size); + else if (new_size < rhte->lxt_cnt) + rc = shrink_lxt(afu, sdev, rhndl, rhte, ctxi, &new_size); + else { + /* + * Rare case where there is already sufficient space, just + * need to perform a translation sync with the AFU. This + * scenario likely follows a previous sync failure during + * a resize operation. Accordingly, perform the heavyweight + * form of translation sync as it is unknown which type of + * resize failed previously. + */ + rc = cxlflash_afu_sync(afu, ctxid, rhndl, AFU_HW_SYNC); + if (unlikely(rc)) { + rc = -EAGAIN; + goto out; + } + } + + resize->hdr.return_flags = 0; + resize->last_lba = (new_size * MC_CHUNK_SIZE * gli->blk_len); + resize->last_lba /= CXLFLASH_BLOCK_SIZE; + resize->last_lba--; + +out: + if (put_ctx) + put_context(ctxi); + dev_dbg(dev, "%s: resized to %llu returning rc=%d\n", + __func__, resize->last_lba, rc); + return rc; +} + +int cxlflash_vlun_resize(struct scsi_device *sdev, + struct dk_cxlflash_resize *resize) +{ + return _cxlflash_vlun_resize(sdev, NULL, resize); +} + +/** + * cxlflash_restore_luntable() - Restore LUN table to prior state + * @cfg: Internal structure associated with the host. + */ +void cxlflash_restore_luntable(struct cxlflash_cfg *cfg) +{ + struct llun_info *lli, *temp; + u32 lind; + int k; + struct device *dev = &cfg->dev->dev; + __be64 __iomem *fc_port_luns; + + mutex_lock(&global.mutex); + + list_for_each_entry_safe(lli, temp, &cfg->lluns, list) { + if (!lli->in_table) + continue; + + lind = lli->lun_index; + dev_dbg(dev, "%s: Virtual LUNs on slot %d:\n", __func__, lind); + + for (k = 0; k < cfg->num_fc_ports; k++) + if (lli->port_sel & (1 << k)) { + fc_port_luns = get_fc_port_luns(cfg, k); + writeq_be(lli->lun_id[k], &fc_port_luns[lind]); + dev_dbg(dev, "\t%d=%llx\n", k, lli->lun_id[k]); + } + } + + mutex_unlock(&global.mutex); +} + +/** + * get_num_ports() - compute number of ports from port selection mask + * @psm: Port selection mask. + * + * Return: Population count of port selection mask + */ +static inline u8 get_num_ports(u32 psm) +{ + static const u8 bits[16] = { 0, 1, 1, 2, 1, 2, 2, 3, + 1, 2, 2, 3, 2, 3, 3, 4 }; + + return bits[psm & 0xf]; +} + +/** + * init_luntable() - write an entry in the LUN table + * @cfg: Internal structure associated with the host. + * @lli: Per adapter LUN information structure. + * + * On successful return, a LUN table entry is created: + * - at the top for LUNs visible on multiple ports. + * - at the bottom for LUNs visible only on one port. + * + * Return: 0 on success, -errno on failure + */ +static int init_luntable(struct cxlflash_cfg *cfg, struct llun_info *lli) +{ + u32 chan; + u32 lind; + u32 nports; + int rc = 0; + int k; + struct device *dev = &cfg->dev->dev; + __be64 __iomem *fc_port_luns; + + mutex_lock(&global.mutex); + + if (lli->in_table) + goto out; + + nports = get_num_ports(lli->port_sel); + if (nports == 0 || nports > cfg->num_fc_ports) { + WARN(1, "Unsupported port configuration nports=%u", nports); + rc = -EIO; + goto out; + } + + if (nports > 1) { + /* + * When LUN is visible from multiple ports, we will put + * it in the top half of the LUN table. + */ + for (k = 0; k < cfg->num_fc_ports; k++) { + if (!(lli->port_sel & (1 << k))) + continue; + + if (cfg->promote_lun_index == cfg->last_lun_index[k]) { + rc = -ENOSPC; + goto out; + } + } + + lind = lli->lun_index = cfg->promote_lun_index; + dev_dbg(dev, "%s: Virtual LUNs on slot %d:\n", __func__, lind); + + for (k = 0; k < cfg->num_fc_ports; k++) { + if (!(lli->port_sel & (1 << k))) + continue; + + fc_port_luns = get_fc_port_luns(cfg, k); + writeq_be(lli->lun_id[k], &fc_port_luns[lind]); + dev_dbg(dev, "\t%d=%llx\n", k, lli->lun_id[k]); + } + + cfg->promote_lun_index++; + } else { + /* + * When LUN is visible only from one port, we will put + * it in the bottom half of the LUN table. + */ + chan = PORTMASK2CHAN(lli->port_sel); + if (cfg->promote_lun_index == cfg->last_lun_index[chan]) { + rc = -ENOSPC; + goto out; + } + + lind = lli->lun_index = cfg->last_lun_index[chan]; + fc_port_luns = get_fc_port_luns(cfg, chan); + writeq_be(lli->lun_id[chan], &fc_port_luns[lind]); + cfg->last_lun_index[chan]--; + dev_dbg(dev, "%s: Virtual LUNs on slot %d:\n\t%d=%llx\n", + __func__, lind, chan, lli->lun_id[chan]); + } + + lli->in_table = true; +out: + mutex_unlock(&global.mutex); + dev_dbg(dev, "%s: returning rc=%d\n", __func__, rc); + return rc; +} + +/** + * cxlflash_disk_virtual_open() - open a virtual disk of specified size + * @sdev: SCSI device associated with LUN owning virtual LUN. + * @arg: UVirtual ioctl data structure. + * + * On successful return, the user is informed of the resource handle + * to be used to identify the virtual LUN and the size (in blocks) of + * the virtual LUN in last LBA format. When the size of the virtual LUN + * is zero, the last LBA is reflected as -1. + * + * Return: 0 on success, -errno on failure + */ +int cxlflash_disk_virtual_open(struct scsi_device *sdev, void *arg) +{ + 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 dk_cxlflash_uvirtual *virt = (struct dk_cxlflash_uvirtual *)arg; + struct dk_cxlflash_resize resize; + + u64 ctxid = DECODE_CTXID(virt->context_id), + rctxid = virt->context_id; + u64 lun_size = virt->lun_size; + u64 last_lba = 0; + u64 rsrc_handle = -1; + + 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); + + /* Setup the LUNs block allocator on first call */ + mutex_lock(&gli->mutex); + if (gli->mode == MODE_NONE) { + rc = init_vlun(lli); + if (rc) { + dev_err(dev, "%s: init_vlun failed rc=%d\n", + __func__, rc); + rc = -ENOMEM; + goto err0; + } + } + + rc = cxlflash_lun_attach(gli, MODE_VIRTUAL, true); + if (unlikely(rc)) { + dev_err(dev, "%s: Failed attach to LUN (VIRTUAL)\n", __func__); + goto err0; + } + mutex_unlock(&gli->mutex); + + rc = init_luntable(cfg, lli); + if (rc) { + dev_err(dev, "%s: init_luntable failed rc=%d\n", __func__, rc); + goto err1; + } + + ctxi = get_context(cfg, rctxid, lli, 0); + if (unlikely(!ctxi)) { + dev_err(dev, "%s: Bad context ctxid=%llu\n", __func__, ctxid); + rc = -EINVAL; + goto err1; + } + + rhte = rhte_checkout(ctxi, lli); + if (unlikely(!rhte)) { + dev_err(dev, "%s: too many opens ctxid=%llu\n", + __func__, ctxid); + rc = -EMFILE; /* too many opens */ + goto err1; + } + + rsrc_handle = (rhte - ctxi->rht_start); + + /* Populate RHT format 0 */ + rhte->nmask = MC_RHT_NMASK; + rhte->fp = SISL_RHT_FP(0U, ctxi->rht_perms); + + /* Resize even if requested size is 0 */ + marshal_virt_to_resize(virt, &resize); + resize.rsrc_handle = rsrc_handle; + rc = _cxlflash_vlun_resize(sdev, ctxi, &resize); + if (rc) { + dev_err(dev, "%s: resize failed rc=%d\n", __func__, rc); + goto err2; + } + last_lba = resize.last_lba; + + if (virt->hdr.flags & DK_CXLFLASH_UVIRTUAL_NEED_WRITE_SAME) + ctxi->rht_needs_ws[rsrc_handle] = true; + + virt->hdr.return_flags = 0; + virt->last_lba = last_lba; + virt->rsrc_handle = rsrc_handle; + + if (get_num_ports(lli->port_sel) > 1) + virt->hdr.return_flags |= DK_CXLFLASH_ALL_PORTS_ACTIVE; +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: + rhte_checkin(ctxi, rhte); +err1: + cxlflash_lun_detach(gli); + goto out; +err0: + /* Special common cleanup prior to successful LUN attach */ + cxlflash_ba_terminate(&gli->blka.ba_lun); + mutex_unlock(&gli->mutex); + goto out; +} + +/** + * clone_lxt() - copies translation tables from source to destination RHTE + * @afu: AFU associated with the host. + * @blka: Block allocator associated with LUN. + * @ctxid: Context ID of context owning the RHTE. + * @rhndl: Resource handle associated with the RHTE. + * @rhte: Destination resource handle entry (RHTE). + * @rhte_src: Source resource handle entry (RHTE). + * + * Return: 0 on success, -errno on failure + */ +static int clone_lxt(struct afu *afu, + struct blka *blka, + ctx_hndl_t ctxid, + res_hndl_t rhndl, + struct sisl_rht_entry *rhte, + struct sisl_rht_entry *rhte_src) +{ + struct cxlflash_cfg *cfg = afu->parent; + struct device *dev = &cfg->dev->dev; + struct sisl_lxt_entry *lxt = NULL; + bool locked = false; + u32 ngrps; + u64 aun; /* chunk# allocated by block allocator */ + int j; + int i = 0; + int rc = 0; + + ngrps = LXT_NUM_GROUPS(rhte_src->lxt_cnt); + + if (ngrps) { + /* allocate new LXTs for clone */ + lxt = kzalloc((sizeof(*lxt) * LXT_GROUP_SIZE * ngrps), + GFP_KERNEL); + if (unlikely(!lxt)) { + rc = -ENOMEM; + goto out; + } + + /* copy over */ + memcpy(lxt, rhte_src->lxt_start, + (sizeof(*lxt) * rhte_src->lxt_cnt)); + + /* clone the LBAs in block allocator via ref_cnt, note that the + * block allocator mutex must be held until it is established + * that this routine will complete without the need for a + * cleanup. + */ + mutex_lock(&blka->mutex); + locked = true; + for (i = 0; i < rhte_src->lxt_cnt; i++) { + aun = (lxt[i].rlba_base >> MC_CHUNK_SHIFT); + if (ba_clone(&blka->ba_lun, aun) == -1ULL) { + rc = -EIO; + goto err; + } + } + } + + /* + * The following sequence is prescribed in the SISlite spec + * for syncing up with the AFU when adding LXT entries. + */ + dma_wmb(); /* Make LXT updates are visible */ + + rhte->lxt_start = lxt; + dma_wmb(); /* Make RHT entry's LXT table update visible */ + + rhte->lxt_cnt = rhte_src->lxt_cnt; + dma_wmb(); /* Make RHT entry's LXT table size update visible */ + + rc = cxlflash_afu_sync(afu, ctxid, rhndl, AFU_LW_SYNC); + if (unlikely(rc)) { + rc = -EAGAIN; + goto err2; + } + +out: + if (locked) + mutex_unlock(&blka->mutex); + dev_dbg(dev, "%s: returning rc=%d\n", __func__, rc); + return rc; +err2: + /* Reset the RHTE */ + rhte->lxt_cnt = 0; + dma_wmb(); + rhte->lxt_start = NULL; + dma_wmb(); +err: + /* free the clones already made */ + for (j = 0; j < i; j++) { + aun = (lxt[j].rlba_base >> MC_CHUNK_SHIFT); + ba_free(&blka->ba_lun, aun); + } + kfree(lxt); + goto out; +} + +/** + * cxlflash_disk_clone() - clone a context by making snapshot of another + * @sdev: SCSI device associated with LUN owning virtual LUN. + * @clone: Clone ioctl data structure. + * + * This routine effectively performs cxlflash_disk_open operation for each + * in-use virtual resource in the source context. Note that the destination + * context must be in pristine state and cannot have any resource handles + * open at the time of the clone. + * + * Return: 0 on success, -errno on failure + */ +int cxlflash_disk_clone(struct scsi_device *sdev, + struct dk_cxlflash_clone *clone) +{ + 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 blka *blka = &gli->blka; + struct afu *afu = cfg->afu; + struct dk_cxlflash_release release = { { 0 }, 0 }; + + struct ctx_info *ctxi_src = NULL, + *ctxi_dst = NULL; + struct lun_access *lun_access_src, *lun_access_dst; + u32 perms; + u64 ctxid_src = DECODE_CTXID(clone->context_id_src), + ctxid_dst = DECODE_CTXID(clone->context_id_dst), + rctxid_src = clone->context_id_src, + rctxid_dst = clone->context_id_dst; + int i, j; + int rc = 0; + bool found; + LIST_HEAD(sidecar); + + dev_dbg(dev, "%s: ctxid_src=%llu ctxid_dst=%llu\n", + __func__, ctxid_src, ctxid_dst); + + /* Do not clone yourself */ + if (unlikely(rctxid_src == rctxid_dst)) { + rc = -EINVAL; + goto out; + } + + if (unlikely(gli->mode != MODE_VIRTUAL)) { + rc = -EINVAL; + dev_dbg(dev, "%s: Only supported on virtual LUNs mode=%u\n", + __func__, gli->mode); + goto out; + } + + ctxi_src = get_context(cfg, rctxid_src, lli, CTX_CTRL_CLONE); + ctxi_dst = get_context(cfg, rctxid_dst, lli, 0); + if (unlikely(!ctxi_src || !ctxi_dst)) { + dev_dbg(dev, "%s: Bad context ctxid_src=%llu ctxid_dst=%llu\n", + __func__, ctxid_src, ctxid_dst); + rc = -EINVAL; + goto out; + } + + /* Verify there is no open resource handle in the destination context */ + for (i = 0; i < MAX_RHT_PER_CONTEXT; i++) + if (ctxi_dst->rht_start[i].nmask != 0) { + rc = -EINVAL; + goto out; + } + + /* Clone LUN access list */ + list_for_each_entry(lun_access_src, &ctxi_src->luns, list) { + found = false; + list_for_each_entry(lun_access_dst, &ctxi_dst->luns, list) + if (lun_access_dst->sdev == lun_access_src->sdev) { + found = true; + break; + } + + if (!found) { + lun_access_dst = kzalloc(sizeof(*lun_access_dst), + GFP_KERNEL); + if (unlikely(!lun_access_dst)) { + dev_err(dev, "%s: lun_access allocation fail\n", + __func__); + rc = -ENOMEM; + goto out; + } + + *lun_access_dst = *lun_access_src; + list_add(&lun_access_dst->list, &sidecar); + } + } + + if (unlikely(!ctxi_src->rht_out)) { + dev_dbg(dev, "%s: Nothing to clone\n", __func__); + goto out_success; + } + + /* User specified permission on attach */ + perms = ctxi_dst->rht_perms; + + /* + * Copy over checked-out RHT (and their associated LXT) entries by + * hand, stopping after we've copied all outstanding entries and + * cleaning up if the clone fails. + * + * Note: This loop is equivalent to performing cxlflash_disk_open and + * cxlflash_vlun_resize. As such, LUN accounting needs to be taken into + * account by attaching after each successful RHT entry clone. In the + * event that a clone failure is experienced, the LUN detach is handled + * via the cleanup performed by _cxlflash_disk_release. + */ + for (i = 0; i < MAX_RHT_PER_CONTEXT; i++) { + if (ctxi_src->rht_out == ctxi_dst->rht_out) + break; + if (ctxi_src->rht_start[i].nmask == 0) + continue; + + /* Consume a destination RHT entry */ + ctxi_dst->rht_out++; + ctxi_dst->rht_start[i].nmask = ctxi_src->rht_start[i].nmask; + ctxi_dst->rht_start[i].fp = + SISL_RHT_FP_CLONE(ctxi_src->rht_start[i].fp, perms); + ctxi_dst->rht_lun[i] = ctxi_src->rht_lun[i]; + + rc = clone_lxt(afu, blka, ctxid_dst, i, + &ctxi_dst->rht_start[i], + &ctxi_src->rht_start[i]); + if (rc) { + marshal_clone_to_rele(clone, &release); + for (j = 0; j < i; j++) { + release.rsrc_handle = j; + _cxlflash_disk_release(sdev, ctxi_dst, + &release); + } + + /* Put back the one we failed on */ + rhte_checkin(ctxi_dst, &ctxi_dst->rht_start[i]); + goto err; + } + + cxlflash_lun_attach(gli, gli->mode, false); + } + +out_success: + list_splice(&sidecar, &ctxi_dst->luns); + + /* fall through */ +out: + if (ctxi_src) + put_context(ctxi_src); + if (ctxi_dst) + put_context(ctxi_dst); + dev_dbg(dev, "%s: returning rc=%d\n", __func__, rc); + return rc; + +err: + list_for_each_entry_safe(lun_access_src, lun_access_dst, &sidecar, list) + kfree(lun_access_src); + goto out; +} |