// SPDX-License-Identifier: GPL-2.0-or-later
/*
* CXL Flash Device Driver
*
* Written by: Manoj N. Kumar <[email protected]>, IBM Corporation
* Matthew R. Ochs <[email protected]>, IBM Corporation
*
* Copyright (C) 2015 IBM Corporation
*/
#include <linux/interrupt.h>
#include <linux/pci.h>
#include <linux/syscalls.h>
#include <linux/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, void *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.
* @arg: 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, void *arg)
{
struct dk_cxlflash_clone *clone = 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 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;
}
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