diff options
Diffstat (limited to 'drivers/misc/genwqe/card_ddcb.c')
| -rw-r--r-- | drivers/misc/genwqe/card_ddcb.c | 1410 |
1 files changed, 1410 insertions, 0 deletions
diff --git a/drivers/misc/genwqe/card_ddcb.c b/drivers/misc/genwqe/card_ddcb.c new file mode 100644 index 000000000..656449cb4 --- /dev/null +++ b/drivers/misc/genwqe/card_ddcb.c @@ -0,0 +1,1410 @@ +/** + * IBM Accelerator Family 'GenWQE' + * + * (C) Copyright IBM Corp. 2013 + * + * Author: Frank Haverkamp <haver@linux.vnet.ibm.com> + * Author: Joerg-Stephan Vogt <jsvogt@de.ibm.com> + * Author: Michael Jung <mijung@gmx.net> + * Author: Michael Ruettger <michael@ibmra.de> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License (version 2 only) + * as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +/* + * Device Driver Control Block (DDCB) queue support. Definition of + * interrupt handlers for queue support as well as triggering the + * health monitor code in case of problems. The current hardware uses + * an MSI interrupt which is shared between error handling and + * functional code. + */ + +#include <linux/types.h> +#include <linux/module.h> +#include <linux/sched.h> +#include <linux/wait.h> +#include <linux/pci.h> +#include <linux/string.h> +#include <linux/dma-mapping.h> +#include <linux/delay.h> +#include <linux/module.h> +#include <linux/interrupt.h> +#include <linux/crc-itu-t.h> + +#include "card_base.h" +#include "card_ddcb.h" + +/* + * N: next DDCB, this is where the next DDCB will be put. + * A: active DDCB, this is where the code will look for the next completion. + * x: DDCB is enqueued, we are waiting for its completion. + + * Situation (1): Empty queue + * +---+---+---+---+---+---+---+---+ + * | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | + * | | | | | | | | | + * +---+---+---+---+---+---+---+---+ + * A/N + * enqueued_ddcbs = A - N = 2 - 2 = 0 + * + * Situation (2): Wrapped, N > A + * +---+---+---+---+---+---+---+---+ + * | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | + * | | | x | x | | | | | + * +---+---+---+---+---+---+---+---+ + * A N + * enqueued_ddcbs = N - A = 4 - 2 = 2 + * + * Situation (3): Queue wrapped, A > N + * +---+---+---+---+---+---+---+---+ + * | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | + * | x | x | | | x | x | x | x | + * +---+---+---+---+---+---+---+---+ + * N A + * enqueued_ddcbs = queue_max - (A - N) = 8 - (4 - 2) = 6 + * + * Situation (4a): Queue full N > A + * +---+---+---+---+---+---+---+---+ + * | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | + * | x | x | x | x | x | x | x | | + * +---+---+---+---+---+---+---+---+ + * A N + * + * enqueued_ddcbs = N - A = 7 - 0 = 7 + * + * Situation (4a): Queue full A > N + * +---+---+---+---+---+---+---+---+ + * | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | + * | x | x | x | | x | x | x | x | + * +---+---+---+---+---+---+---+---+ + * N A + * enqueued_ddcbs = queue_max - (A - N) = 8 - (4 - 3) = 7 + */ + +static int queue_empty(struct ddcb_queue *queue) +{ + return queue->ddcb_next == queue->ddcb_act; +} + +static int queue_enqueued_ddcbs(struct ddcb_queue *queue) +{ + if (queue->ddcb_next >= queue->ddcb_act) + return queue->ddcb_next - queue->ddcb_act; + + return queue->ddcb_max - (queue->ddcb_act - queue->ddcb_next); +} + +static int queue_free_ddcbs(struct ddcb_queue *queue) +{ + int free_ddcbs = queue->ddcb_max - queue_enqueued_ddcbs(queue) - 1; + + if (WARN_ON_ONCE(free_ddcbs < 0)) { /* must never ever happen! */ + return 0; + } + return free_ddcbs; +} + +/* + * Use of the PRIV field in the DDCB for queue debugging: + * + * (1) Trying to get rid of a DDCB which saw a timeout: + * pddcb->priv[6] = 0xcc; # cleared + * + * (2) Append a DDCB via NEXT bit: + * pddcb->priv[7] = 0xaa; # appended + * + * (3) DDCB needed tapping: + * pddcb->priv[7] = 0xbb; # tapped + * + * (4) DDCB marked as correctly finished: + * pddcb->priv[6] = 0xff; # finished + */ + +static inline void ddcb_mark_tapped(struct ddcb *pddcb) +{ + pddcb->priv[7] = 0xbb; /* tapped */ +} + +static inline void ddcb_mark_appended(struct ddcb *pddcb) +{ + pddcb->priv[7] = 0xaa; /* appended */ +} + +static inline void ddcb_mark_cleared(struct ddcb *pddcb) +{ + pddcb->priv[6] = 0xcc; /* cleared */ +} + +static inline void ddcb_mark_finished(struct ddcb *pddcb) +{ + pddcb->priv[6] = 0xff; /* finished */ +} + +static inline void ddcb_mark_unused(struct ddcb *pddcb) +{ + pddcb->priv_64 = cpu_to_be64(0); /* not tapped */ +} + +/** + * genwqe_crc16() - Generate 16-bit crc as required for DDCBs + * @buff: pointer to data buffer + * @len: length of data for calculation + * @init: initial crc (0xffff at start) + * + * Polynomial = x^16 + x^12 + x^5 + 1 (0x1021) + * Example: 4 bytes 0x01 0x02 0x03 0x04 with init = 0xffff + * should result in a crc16 of 0x89c3 + * + * Return: crc16 checksum in big endian format ! + */ +static inline u16 genwqe_crc16(const u8 *buff, size_t len, u16 init) +{ + return crc_itu_t(init, buff, len); +} + +static void print_ddcb_info(struct genwqe_dev *cd, struct ddcb_queue *queue) +{ + int i; + struct ddcb *pddcb; + unsigned long flags; + struct pci_dev *pci_dev = cd->pci_dev; + + spin_lock_irqsave(&cd->print_lock, flags); + + dev_info(&pci_dev->dev, + "DDCB list for card #%d (ddcb_act=%d / ddcb_next=%d):\n", + cd->card_idx, queue->ddcb_act, queue->ddcb_next); + + pddcb = queue->ddcb_vaddr; + for (i = 0; i < queue->ddcb_max; i++) { + dev_err(&pci_dev->dev, + " %c %-3d: RETC=%03x SEQ=%04x HSI=%02X SHI=%02x PRIV=%06llx CMD=%03x\n", + i == queue->ddcb_act ? '>' : ' ', + i, + be16_to_cpu(pddcb->retc_16), + be16_to_cpu(pddcb->seqnum_16), + pddcb->hsi, + pddcb->shi, + be64_to_cpu(pddcb->priv_64), + pddcb->cmd); + pddcb++; + } + spin_unlock_irqrestore(&cd->print_lock, flags); +} + +struct genwqe_ddcb_cmd *ddcb_requ_alloc(void) +{ + struct ddcb_requ *req; + + req = kzalloc(sizeof(*req), GFP_KERNEL); + if (!req) + return NULL; + + return &req->cmd; +} + +void ddcb_requ_free(struct genwqe_ddcb_cmd *cmd) +{ + struct ddcb_requ *req = container_of(cmd, struct ddcb_requ, cmd); + + kfree(req); +} + +static inline enum genwqe_requ_state ddcb_requ_get_state(struct ddcb_requ *req) +{ + return req->req_state; +} + +static inline void ddcb_requ_set_state(struct ddcb_requ *req, + enum genwqe_requ_state new_state) +{ + req->req_state = new_state; +} + +static inline int ddcb_requ_collect_debug_data(struct ddcb_requ *req) +{ + return req->cmd.ddata_addr != 0x0; +} + +/** + * ddcb_requ_finished() - Returns the hardware state of the associated DDCB + * @cd: pointer to genwqe device descriptor + * @req: DDCB work request + * + * Status of ddcb_requ mirrors this hardware state, but is copied in + * the ddcb_requ on interrupt/polling function. The lowlevel code + * should check the hardware state directly, the higher level code + * should check the copy. + * + * This function will also return true if the state of the queue is + * not GENWQE_CARD_USED. This enables us to purge all DDCBs in the + * shutdown case. + */ +static int ddcb_requ_finished(struct genwqe_dev *cd, struct ddcb_requ *req) +{ + return (ddcb_requ_get_state(req) == GENWQE_REQU_FINISHED) || + (cd->card_state != GENWQE_CARD_USED); +} + +/** + * enqueue_ddcb() - Enqueue a DDCB + * @cd: pointer to genwqe device descriptor + * @queue: queue this operation should be done on + * @ddcb_no: pointer to ddcb number being tapped + * + * Start execution of DDCB by tapping or append to queue via NEXT + * bit. This is done by an atomic 'compare and swap' instruction and + * checking SHI and HSI of the previous DDCB. + * + * This function must only be called with ddcb_lock held. + * + * Return: 1 if new DDCB is appended to previous + * 2 if DDCB queue is tapped via register/simulation + */ +#define RET_DDCB_APPENDED 1 +#define RET_DDCB_TAPPED 2 + +static int enqueue_ddcb(struct genwqe_dev *cd, struct ddcb_queue *queue, + struct ddcb *pddcb, int ddcb_no) +{ + unsigned int try; + int prev_no; + struct ddcb *prev_ddcb; + __be32 old, new, icrc_hsi_shi; + u64 num; + + /* + * For performance checks a Dispatch Timestamp can be put into + * DDCB It is supposed to use the SLU's free running counter, + * but this requires PCIe cycles. + */ + ddcb_mark_unused(pddcb); + + /* check previous DDCB if already fetched */ + prev_no = (ddcb_no == 0) ? queue->ddcb_max - 1 : ddcb_no - 1; + prev_ddcb = &queue->ddcb_vaddr[prev_no]; + + /* + * It might have happened that the HSI.FETCHED bit is + * set. Retry in this case. Therefore I expect maximum 2 times + * trying. + */ + ddcb_mark_appended(pddcb); + for (try = 0; try < 2; try++) { + old = prev_ddcb->icrc_hsi_shi_32; /* read SHI/HSI in BE32 */ + + /* try to append via NEXT bit if prev DDCB is not completed */ + if ((old & DDCB_COMPLETED_BE32) != 0x00000000) + break; + + new = (old | DDCB_NEXT_BE32); + + wmb(); /* need to ensure write ordering */ + icrc_hsi_shi = cmpxchg(&prev_ddcb->icrc_hsi_shi_32, old, new); + + if (icrc_hsi_shi == old) + return RET_DDCB_APPENDED; /* appended to queue */ + } + + /* Queue must be re-started by updating QUEUE_OFFSET */ + ddcb_mark_tapped(pddcb); + num = (u64)ddcb_no << 8; + + wmb(); /* need to ensure write ordering */ + __genwqe_writeq(cd, queue->IO_QUEUE_OFFSET, num); /* start queue */ + + return RET_DDCB_TAPPED; +} + +/** + * copy_ddcb_results() - Copy output state from real DDCB to request + * + * Copy DDCB ASV to request struct. There is no endian + * conversion made, since data structure in ASV is still + * unknown here. + * + * This is needed by: + * - genwqe_purge_ddcb() + * - genwqe_check_ddcb_queue() + */ +static void copy_ddcb_results(struct ddcb_requ *req, int ddcb_no) +{ + struct ddcb_queue *queue = req->queue; + struct ddcb *pddcb = &queue->ddcb_vaddr[req->num]; + + memcpy(&req->cmd.asv[0], &pddcb->asv[0], DDCB_ASV_LENGTH); + + /* copy status flags of the variant part */ + req->cmd.vcrc = be16_to_cpu(pddcb->vcrc_16); + req->cmd.deque_ts = be64_to_cpu(pddcb->deque_ts_64); + req->cmd.cmplt_ts = be64_to_cpu(pddcb->cmplt_ts_64); + + req->cmd.attn = be16_to_cpu(pddcb->attn_16); + req->cmd.progress = be32_to_cpu(pddcb->progress_32); + req->cmd.retc = be16_to_cpu(pddcb->retc_16); + + if (ddcb_requ_collect_debug_data(req)) { + int prev_no = (ddcb_no == 0) ? + queue->ddcb_max - 1 : ddcb_no - 1; + struct ddcb *prev_pddcb = &queue->ddcb_vaddr[prev_no]; + + memcpy(&req->debug_data.ddcb_finished, pddcb, + sizeof(req->debug_data.ddcb_finished)); + memcpy(&req->debug_data.ddcb_prev, prev_pddcb, + sizeof(req->debug_data.ddcb_prev)); + } +} + +/** + * genwqe_check_ddcb_queue() - Checks DDCB queue for completed work equests. + * @cd: pointer to genwqe device descriptor + * + * Return: Number of DDCBs which were finished + */ +static int genwqe_check_ddcb_queue(struct genwqe_dev *cd, + struct ddcb_queue *queue) +{ + unsigned long flags; + int ddcbs_finished = 0; + struct pci_dev *pci_dev = cd->pci_dev; + + spin_lock_irqsave(&queue->ddcb_lock, flags); + + /* FIXME avoid soft locking CPU */ + while (!queue_empty(queue) && (ddcbs_finished < queue->ddcb_max)) { + + struct ddcb *pddcb; + struct ddcb_requ *req; + u16 vcrc, vcrc_16, retc_16; + + pddcb = &queue->ddcb_vaddr[queue->ddcb_act]; + + if ((pddcb->icrc_hsi_shi_32 & DDCB_COMPLETED_BE32) == + 0x00000000) + goto go_home; /* not completed, continue waiting */ + + wmb(); /* Add sync to decouple prev. read operations */ + + /* Note: DDCB could be purged */ + req = queue->ddcb_req[queue->ddcb_act]; + if (req == NULL) { + /* this occurs if DDCB is purged, not an error */ + /* Move active DDCB further; Nothing to do anymore. */ + goto pick_next_one; + } + + /* + * HSI=0x44 (fetched and completed), but RETC is + * 0x101, or even worse 0x000. + * + * In case of seeing the queue in inconsistent state + * we read the errcnts and the queue status to provide + * a trigger for our PCIe analyzer stop capturing. + */ + retc_16 = be16_to_cpu(pddcb->retc_16); + if ((pddcb->hsi == 0x44) && (retc_16 <= 0x101)) { + u64 errcnts, status; + u64 ddcb_offs = (u64)pddcb - (u64)queue->ddcb_vaddr; + + errcnts = __genwqe_readq(cd, queue->IO_QUEUE_ERRCNTS); + status = __genwqe_readq(cd, queue->IO_QUEUE_STATUS); + + dev_err(&pci_dev->dev, + "[%s] SEQN=%04x HSI=%02x RETC=%03x Q_ERRCNTS=%016llx Q_STATUS=%016llx DDCB_DMA_ADDR=%016llx\n", + __func__, be16_to_cpu(pddcb->seqnum_16), + pddcb->hsi, retc_16, errcnts, status, + queue->ddcb_daddr + ddcb_offs); + } + + copy_ddcb_results(req, queue->ddcb_act); + queue->ddcb_req[queue->ddcb_act] = NULL; /* take from queue */ + + dev_dbg(&pci_dev->dev, "FINISHED DDCB#%d\n", req->num); + genwqe_hexdump(pci_dev, pddcb, sizeof(*pddcb)); + + ddcb_mark_finished(pddcb); + + /* calculate CRC_16 to see if VCRC is correct */ + vcrc = genwqe_crc16(pddcb->asv, + VCRC_LENGTH(req->cmd.asv_length), + 0xffff); + vcrc_16 = be16_to_cpu(pddcb->vcrc_16); + if (vcrc != vcrc_16) { + printk_ratelimited(KERN_ERR + "%s %s: err: wrong VCRC pre=%02x vcrc_len=%d bytes vcrc_data=%04x is not vcrc_card=%04x\n", + GENWQE_DEVNAME, dev_name(&pci_dev->dev), + pddcb->pre, VCRC_LENGTH(req->cmd.asv_length), + vcrc, vcrc_16); + } + + ddcb_requ_set_state(req, GENWQE_REQU_FINISHED); + queue->ddcbs_completed++; + queue->ddcbs_in_flight--; + + /* wake up process waiting for this DDCB, and + processes on the busy queue */ + wake_up_interruptible(&queue->ddcb_waitqs[queue->ddcb_act]); + wake_up_interruptible(&queue->busy_waitq); + +pick_next_one: + queue->ddcb_act = (queue->ddcb_act + 1) % queue->ddcb_max; + ddcbs_finished++; + } + + go_home: + spin_unlock_irqrestore(&queue->ddcb_lock, flags); + return ddcbs_finished; +} + +/** + * __genwqe_wait_ddcb(): Waits until DDCB is completed + * @cd: pointer to genwqe device descriptor + * @req: pointer to requsted DDCB parameters + * + * The Service Layer will update the RETC in DDCB when processing is + * pending or done. + * + * Return: > 0 remaining jiffies, DDCB completed + * -ETIMEDOUT when timeout + * -ERESTARTSYS when ^C + * -EINVAL when unknown error condition + * + * When an error is returned the called needs to ensure that + * purge_ddcb() is being called to get the &req removed from the + * queue. + */ +int __genwqe_wait_ddcb(struct genwqe_dev *cd, struct ddcb_requ *req) +{ + int rc; + unsigned int ddcb_no; + struct ddcb_queue *queue; + struct pci_dev *pci_dev = cd->pci_dev; + + if (req == NULL) + return -EINVAL; + + queue = req->queue; + if (queue == NULL) + return -EINVAL; + + ddcb_no = req->num; + if (ddcb_no >= queue->ddcb_max) + return -EINVAL; + + rc = wait_event_interruptible_timeout(queue->ddcb_waitqs[ddcb_no], + ddcb_requ_finished(cd, req), + GENWQE_DDCB_SOFTWARE_TIMEOUT * HZ); + + /* + * We need to distinguish 3 cases here: + * 1. rc == 0 timeout occured + * 2. rc == -ERESTARTSYS signal received + * 3. rc > 0 remaining jiffies condition is true + */ + if (rc == 0) { + struct ddcb_queue *queue = req->queue; + struct ddcb *pddcb; + + /* + * Timeout may be caused by long task switching time. + * When timeout happens, check if the request has + * meanwhile completed. + */ + genwqe_check_ddcb_queue(cd, req->queue); + if (ddcb_requ_finished(cd, req)) + return rc; + + dev_err(&pci_dev->dev, + "[%s] err: DDCB#%d timeout rc=%d state=%d req @ %p\n", + __func__, req->num, rc, ddcb_requ_get_state(req), + req); + dev_err(&pci_dev->dev, + "[%s] IO_QUEUE_STATUS=0x%016llx\n", __func__, + __genwqe_readq(cd, queue->IO_QUEUE_STATUS)); + + pddcb = &queue->ddcb_vaddr[req->num]; + genwqe_hexdump(pci_dev, pddcb, sizeof(*pddcb)); + + print_ddcb_info(cd, req->queue); + return -ETIMEDOUT; + + } else if (rc == -ERESTARTSYS) { + return rc; + /* + * EINTR: Stops the application + * ERESTARTSYS: Restartable systemcall; called again + */ + + } else if (rc < 0) { + dev_err(&pci_dev->dev, + "[%s] err: DDCB#%d unknown result (rc=%d) %d!\n", + __func__, req->num, rc, ddcb_requ_get_state(req)); + return -EINVAL; + } + + /* Severe error occured. Driver is forced to stop operation */ + if (cd->card_state != GENWQE_CARD_USED) { + dev_err(&pci_dev->dev, + "[%s] err: DDCB#%d forced to stop (rc=%d)\n", + __func__, req->num, rc); + return -EIO; + } + return rc; +} + +/** + * get_next_ddcb() - Get next available DDCB + * @cd: pointer to genwqe device descriptor + * + * DDCB's content is completely cleared but presets for PRE and + * SEQNUM. This function must only be called when ddcb_lock is held. + * + * Return: NULL if no empty DDCB available otherwise ptr to next DDCB. + */ +static struct ddcb *get_next_ddcb(struct genwqe_dev *cd, + struct ddcb_queue *queue, + int *num) +{ + u64 *pu64; + struct ddcb *pddcb; + + if (queue_free_ddcbs(queue) == 0) /* queue is full */ + return NULL; + + /* find new ddcb */ + pddcb = &queue->ddcb_vaddr[queue->ddcb_next]; + + /* if it is not completed, we are not allowed to use it */ + /* barrier(); */ + if ((pddcb->icrc_hsi_shi_32 & DDCB_COMPLETED_BE32) == 0x00000000) + return NULL; + + *num = queue->ddcb_next; /* internal DDCB number */ + queue->ddcb_next = (queue->ddcb_next + 1) % queue->ddcb_max; + + /* clear important DDCB fields */ + pu64 = (u64 *)pddcb; + pu64[0] = 0ULL; /* offs 0x00 (ICRC,HSI,SHI,...) */ + pu64[1] = 0ULL; /* offs 0x01 (ACFUNC,CMD...) */ + + /* destroy previous results in ASV */ + pu64[0x80/8] = 0ULL; /* offs 0x80 (ASV + 0) */ + pu64[0x88/8] = 0ULL; /* offs 0x88 (ASV + 0x08) */ + pu64[0x90/8] = 0ULL; /* offs 0x90 (ASV + 0x10) */ + pu64[0x98/8] = 0ULL; /* offs 0x98 (ASV + 0x18) */ + pu64[0xd0/8] = 0ULL; /* offs 0xd0 (RETC,ATTN...) */ + + pddcb->pre = DDCB_PRESET_PRE; /* 128 */ + pddcb->seqnum_16 = cpu_to_be16(queue->ddcb_seq++); + return pddcb; +} + +/** + * __genwqe_purge_ddcb() - Remove a DDCB from the workqueue + * @cd: genwqe device descriptor + * @req: DDCB request + * + * This will fail when the request was already FETCHED. In this case + * we need to wait until it is finished. Else the DDCB can be + * reused. This function also ensures that the request data structure + * is removed from ddcb_req[]. + * + * Do not forget to call this function when genwqe_wait_ddcb() fails, + * such that the request gets really removed from ddcb_req[]. + * + * Return: 0 success + */ +int __genwqe_purge_ddcb(struct genwqe_dev *cd, struct ddcb_requ *req) +{ + struct ddcb *pddcb = NULL; + unsigned int t; + unsigned long flags; + struct ddcb_queue *queue = req->queue; + struct pci_dev *pci_dev = cd->pci_dev; + u64 queue_status; + __be32 icrc_hsi_shi = 0x0000; + __be32 old, new; + + /* unsigned long flags; */ + if (GENWQE_DDCB_SOFTWARE_TIMEOUT <= 0) { + dev_err(&pci_dev->dev, + "[%s] err: software timeout is not set!\n", __func__); + return -EFAULT; + } + + pddcb = &queue->ddcb_vaddr[req->num]; + + for (t = 0; t < GENWQE_DDCB_SOFTWARE_TIMEOUT * 10; t++) { + + spin_lock_irqsave(&queue->ddcb_lock, flags); + + /* Check if req was meanwhile finished */ + if (ddcb_requ_get_state(req) == GENWQE_REQU_FINISHED) + goto go_home; + + /* try to set PURGE bit if FETCHED/COMPLETED are not set */ + old = pddcb->icrc_hsi_shi_32; /* read SHI/HSI in BE32 */ + if ((old & DDCB_FETCHED_BE32) == 0x00000000) { + + new = (old | DDCB_PURGE_BE32); + icrc_hsi_shi = cmpxchg(&pddcb->icrc_hsi_shi_32, + old, new); + if (icrc_hsi_shi == old) + goto finish_ddcb; + } + + /* normal finish with HSI bit */ + barrier(); + icrc_hsi_shi = pddcb->icrc_hsi_shi_32; + if (icrc_hsi_shi & DDCB_COMPLETED_BE32) + goto finish_ddcb; + + spin_unlock_irqrestore(&queue->ddcb_lock, flags); + + /* + * Here the check_ddcb() function will most likely + * discover this DDCB to be finished some point in + * time. It will mark the req finished and free it up + * in the list. + */ + + copy_ddcb_results(req, req->num); /* for the failing case */ + msleep(100); /* sleep for 1/10 second and try again */ + continue; + +finish_ddcb: + copy_ddcb_results(req, req->num); + ddcb_requ_set_state(req, GENWQE_REQU_FINISHED); + queue->ddcbs_in_flight--; + queue->ddcb_req[req->num] = NULL; /* delete from array */ + ddcb_mark_cleared(pddcb); + + /* Move active DDCB further; Nothing to do here anymore. */ + + /* + * We need to ensure that there is at least one free + * DDCB in the queue. To do that, we must update + * ddcb_act only if the COMPLETED bit is set for the + * DDCB we are working on else we treat that DDCB even + * if we PURGED it as occupied (hardware is supposed + * to set the COMPLETED bit yet!). + */ + icrc_hsi_shi = pddcb->icrc_hsi_shi_32; + if ((icrc_hsi_shi & DDCB_COMPLETED_BE32) && + (queue->ddcb_act == req->num)) { + queue->ddcb_act = ((queue->ddcb_act + 1) % + queue->ddcb_max); + } +go_home: + spin_unlock_irqrestore(&queue->ddcb_lock, flags); + return 0; + } + + /* + * If the card is dead and the queue is forced to stop, we + * might see this in the queue status register. + */ + queue_status = __genwqe_readq(cd, queue->IO_QUEUE_STATUS); + + dev_dbg(&pci_dev->dev, "UN/FINISHED DDCB#%d\n", req->num); + genwqe_hexdump(pci_dev, pddcb, sizeof(*pddcb)); + + dev_err(&pci_dev->dev, + "[%s] err: DDCB#%d not purged and not completed after %d seconds QSTAT=%016llx!!\n", + __func__, req->num, GENWQE_DDCB_SOFTWARE_TIMEOUT, + queue_status); + + print_ddcb_info(cd, req->queue); + + return -EFAULT; +} + +int genwqe_init_debug_data(struct genwqe_dev *cd, struct genwqe_debug_data *d) +{ + int len; + struct pci_dev *pci_dev = cd->pci_dev; + + if (d == NULL) { + dev_err(&pci_dev->dev, + "[%s] err: invalid memory for debug data!\n", + __func__); + return -EFAULT; + } + + len = sizeof(d->driver_version); + snprintf(d->driver_version, len, "%s", DRV_VERSION); + d->slu_unitcfg = cd->slu_unitcfg; + d->app_unitcfg = cd->app_unitcfg; + return 0; +} + +/** + * __genwqe_enqueue_ddcb() - Enqueue a DDCB + * @cd: pointer to genwqe device descriptor + * @req: pointer to DDCB execution request + * @f_flags: file mode: blocking, non-blocking + * + * Return: 0 if enqueuing succeeded + * -EIO if card is unusable/PCIe problems + * -EBUSY if enqueuing failed + */ +int __genwqe_enqueue_ddcb(struct genwqe_dev *cd, struct ddcb_requ *req, + unsigned int f_flags) +{ + struct ddcb *pddcb; + unsigned long flags; + struct ddcb_queue *queue; + struct pci_dev *pci_dev = cd->pci_dev; + u16 icrc; + + retry: + if (cd->card_state != GENWQE_CARD_USED) { + printk_ratelimited(KERN_ERR + "%s %s: [%s] Card is unusable/PCIe problem Req#%d\n", + GENWQE_DEVNAME, dev_name(&pci_dev->dev), + __func__, req->num); + return -EIO; + } + + queue = req->queue = &cd->queue; + + /* FIXME circumvention to improve performance when no irq is + * there. + */ + if (GENWQE_POLLING_ENABLED) + genwqe_check_ddcb_queue(cd, queue); + + /* + * It must be ensured to process all DDCBs in successive + * order. Use a lock here in order to prevent nested DDCB + * enqueuing. + */ + spin_lock_irqsave(&queue->ddcb_lock, flags); + + pddcb = get_next_ddcb(cd, queue, &req->num); /* get ptr and num */ + if (pddcb == NULL) { + int rc; + + spin_unlock_irqrestore(&queue->ddcb_lock, flags); + + if (f_flags & O_NONBLOCK) { + queue->return_on_busy++; + return -EBUSY; + } + + queue->wait_on_busy++; + rc = wait_event_interruptible(queue->busy_waitq, + queue_free_ddcbs(queue) != 0); + dev_dbg(&pci_dev->dev, "[%s] waiting for free DDCB: rc=%d\n", + __func__, rc); + if (rc == -ERESTARTSYS) + return rc; /* interrupted by a signal */ + + goto retry; + } + + if (queue->ddcb_req[req->num] != NULL) { + spin_unlock_irqrestore(&queue->ddcb_lock, flags); + + dev_err(&pci_dev->dev, + "[%s] picked DDCB %d with req=%p still in use!!\n", + __func__, req->num, req); + return -EFAULT; + } + ddcb_requ_set_state(req, GENWQE_REQU_ENQUEUED); + queue->ddcb_req[req->num] = req; + + pddcb->cmdopts_16 = cpu_to_be16(req->cmd.cmdopts); + pddcb->cmd = req->cmd.cmd; + pddcb->acfunc = req->cmd.acfunc; /* functional unit */ + + /* + * We know that we can get retc 0x104 with CRC error, do not + * stop the queue in those cases for this command. XDIR = 1 + * does not work for old SLU versions. + * + * Last bitstream with the old XDIR behavior had SLU_ID + * 0x34199. + */ + if ((cd->slu_unitcfg & 0xFFFF0ull) > 0x34199ull) + pddcb->xdir = 0x1; + else + pddcb->xdir = 0x0; + + + pddcb->psp = (((req->cmd.asiv_length / 8) << 4) | + ((req->cmd.asv_length / 8))); + pddcb->disp_ts_64 = cpu_to_be64(req->cmd.disp_ts); + + /* + * If copying the whole DDCB_ASIV_LENGTH is impacting + * performance we need to change it to + * req->cmd.asiv_length. But simulation benefits from some + * non-architectured bits behind the architectured content. + * + * How much data is copied depends on the availability of the + * ATS field, which was introduced late. If the ATS field is + * supported ASIV is 8 bytes shorter than it used to be. Since + * the ATS field is copied too, the code should do exactly + * what it did before, but I wanted to make copying of the ATS + * field very explicit. + */ + if (genwqe_get_slu_id(cd) <= 0x2) { + memcpy(&pddcb->__asiv[0], /* destination */ + &req->cmd.__asiv[0], /* source */ + DDCB_ASIV_LENGTH); /* req->cmd.asiv_length */ + } else { + pddcb->n.ats_64 = cpu_to_be64(req->cmd.ats); + memcpy(&pddcb->n.asiv[0], /* destination */ + &req->cmd.asiv[0], /* source */ + DDCB_ASIV_LENGTH_ATS); /* req->cmd.asiv_length */ + } + + pddcb->icrc_hsi_shi_32 = cpu_to_be32(0x00000000); /* for crc */ + + /* + * Calculate CRC_16 for corresponding range PSP(7:4). Include + * empty 4 bytes prior to the data. + */ + icrc = genwqe_crc16((const u8 *)pddcb, + ICRC_LENGTH(req->cmd.asiv_length), 0xffff); + pddcb->icrc_hsi_shi_32 = cpu_to_be32((u32)icrc << 16); + + /* enable DDCB completion irq */ + if (!GENWQE_POLLING_ENABLED) + pddcb->icrc_hsi_shi_32 |= DDCB_INTR_BE32; + + dev_dbg(&pci_dev->dev, "INPUT DDCB#%d\n", req->num); + genwqe_hexdump(pci_dev, pddcb, sizeof(*pddcb)); + + if (ddcb_requ_collect_debug_data(req)) { + /* use the kernel copy of debug data. copying back to + user buffer happens later */ + + genwqe_init_debug_data(cd, &req->debug_data); + memcpy(&req->debug_data.ddcb_before, pddcb, + sizeof(req->debug_data.ddcb_before)); + } + + enqueue_ddcb(cd, queue, pddcb, req->num); + queue->ddcbs_in_flight++; + + if (queue->ddcbs_in_flight > queue->ddcbs_max_in_flight) + queue->ddcbs_max_in_flight = queue->ddcbs_in_flight; + + ddcb_requ_set_state(req, GENWQE_REQU_TAPPED); + spin_unlock_irqrestore(&queue->ddcb_lock, flags); + wake_up_interruptible(&cd->queue_waitq); + + return 0; +} + +/** + * __genwqe_execute_raw_ddcb() - Setup and execute DDCB + * @cd: pointer to genwqe device descriptor + * @req: user provided DDCB request + * @f_flags: file mode: blocking, non-blocking + */ +int __genwqe_execute_raw_ddcb(struct genwqe_dev *cd, + struct genwqe_ddcb_cmd *cmd, + unsigned int f_flags) +{ + int rc = 0; + struct pci_dev *pci_dev = cd->pci_dev; + struct ddcb_requ *req = container_of(cmd, struct ddcb_requ, cmd); + + if (cmd->asiv_length > DDCB_ASIV_LENGTH) { + dev_err(&pci_dev->dev, "[%s] err: wrong asiv_length of %d\n", + __func__, cmd->asiv_length); + return -EINVAL; + } + if (cmd->asv_length > DDCB_ASV_LENGTH) { + dev_err(&pci_dev->dev, "[%s] err: wrong asv_length of %d\n", + __func__, cmd->asiv_length); + return -EINVAL; + } + rc = __genwqe_enqueue_ddcb(cd, req, f_flags); + if (rc != 0) + return rc; + + rc = __genwqe_wait_ddcb(cd, req); + if (rc < 0) /* error or signal interrupt */ + goto err_exit; + + if (ddcb_requ_collect_debug_data(req)) { + if (copy_to_user((struct genwqe_debug_data __user *) + (unsigned long)cmd->ddata_addr, + &req->debug_data, + sizeof(struct genwqe_debug_data))) + return -EFAULT; + } + + /* + * Higher values than 0x102 indicate completion with faults, + * lower values than 0x102 indicate processing faults. Note + * that DDCB might have been purged. E.g. Cntl+C. + */ + if (cmd->retc != DDCB_RETC_COMPLETE) { + /* This might happen e.g. flash read, and needs to be + handled by the upper layer code. */ + rc = -EBADMSG; /* not processed/error retc */ + } + + return rc; + + err_exit: + __genwqe_purge_ddcb(cd, req); + + if (ddcb_requ_collect_debug_data(req)) { + if (copy_to_user((struct genwqe_debug_data __user *) + (unsigned long)cmd->ddata_addr, + &req->debug_data, + sizeof(struct genwqe_debug_data))) + return -EFAULT; + } + return rc; +} + +/** + * genwqe_next_ddcb_ready() - Figure out if the next DDCB is already finished + * + * We use this as condition for our wait-queue code. + */ +static int genwqe_next_ddcb_ready(struct genwqe_dev *cd) +{ + unsigned long flags; + struct ddcb *pddcb; + struct ddcb_queue *queue = &cd->queue; + + spin_lock_irqsave(&queue->ddcb_lock, flags); + + if (queue_empty(queue)) { /* emtpy queue */ + spin_unlock_irqrestore(&queue->ddcb_lock, flags); + return 0; + } + + pddcb = &queue->ddcb_vaddr[queue->ddcb_act]; + if (pddcb->icrc_hsi_shi_32 & DDCB_COMPLETED_BE32) { /* ddcb ready */ + spin_unlock_irqrestore(&queue->ddcb_lock, flags); + return 1; + } + + spin_unlock_irqrestore(&queue->ddcb_lock, flags); + return 0; +} + +/** + * genwqe_ddcbs_in_flight() - Check how many DDCBs are in flight + * + * Keep track on the number of DDCBs which ware currently in the + * queue. This is needed for statistics as well as conditon if we want + * to wait or better do polling in case of no interrupts available. + */ +int genwqe_ddcbs_in_flight(struct genwqe_dev *cd) +{ + unsigned long flags; + int ddcbs_in_flight = 0; + struct ddcb_queue *queue = &cd->queue; + + spin_lock_irqsave(&queue->ddcb_lock, flags); + ddcbs_in_flight += queue->ddcbs_in_flight; + spin_unlock_irqrestore(&queue->ddcb_lock, flags); + + return ddcbs_in_flight; +} + +static int setup_ddcb_queue(struct genwqe_dev *cd, struct ddcb_queue *queue) +{ + int rc, i; + struct ddcb *pddcb; + u64 val64; + unsigned int queue_size; + struct pci_dev *pci_dev = cd->pci_dev; + + if (GENWQE_DDCB_MAX < 2) + return -EINVAL; + + queue_size = roundup(GENWQE_DDCB_MAX * sizeof(struct ddcb), PAGE_SIZE); + + queue->ddcbs_in_flight = 0; /* statistics */ + queue->ddcbs_max_in_flight = 0; + queue->ddcbs_completed = 0; + queue->return_on_busy = 0; + queue->wait_on_busy = 0; + + queue->ddcb_seq = 0x100; /* start sequence number */ + queue->ddcb_max = GENWQE_DDCB_MAX; + queue->ddcb_vaddr = __genwqe_alloc_consistent(cd, queue_size, + &queue->ddcb_daddr); + if (queue->ddcb_vaddr == NULL) { + dev_err(&pci_dev->dev, + "[%s] **err: could not allocate DDCB **\n", __func__); + return -ENOMEM; + } + queue->ddcb_req = kcalloc(queue->ddcb_max, sizeof(struct ddcb_requ *), + GFP_KERNEL); + if (!queue->ddcb_req) { + rc = -ENOMEM; + goto free_ddcbs; + } + + queue->ddcb_waitqs = kcalloc(queue->ddcb_max, + sizeof(wait_queue_head_t), + GFP_KERNEL); + if (!queue->ddcb_waitqs) { + rc = -ENOMEM; + goto free_requs; + } + + for (i = 0; i < queue->ddcb_max; i++) { + pddcb = &queue->ddcb_vaddr[i]; /* DDCBs */ + pddcb->icrc_hsi_shi_32 = DDCB_COMPLETED_BE32; + pddcb->retc_16 = cpu_to_be16(0xfff); + + queue->ddcb_req[i] = NULL; /* requests */ + init_waitqueue_head(&queue->ddcb_waitqs[i]); /* waitqueues */ + } + + queue->ddcb_act = 0; + queue->ddcb_next = 0; /* queue is empty */ + + spin_lock_init(&queue->ddcb_lock); + init_waitqueue_head(&queue->busy_waitq); + + val64 = ((u64)(queue->ddcb_max - 1) << 8); /* lastptr */ + __genwqe_writeq(cd, queue->IO_QUEUE_CONFIG, 0x07); /* iCRC/vCRC */ + __genwqe_writeq(cd, queue->IO_QUEUE_SEGMENT, queue->ddcb_daddr); + __genwqe_writeq(cd, queue->IO_QUEUE_INITSQN, queue->ddcb_seq); + __genwqe_writeq(cd, queue->IO_QUEUE_WRAP, val64); + return 0; + + free_requs: + kfree(queue->ddcb_req); + queue->ddcb_req = NULL; + free_ddcbs: + __genwqe_free_consistent(cd, queue_size, queue->ddcb_vaddr, + queue->ddcb_daddr); + queue->ddcb_vaddr = NULL; + queue->ddcb_daddr = 0ull; + return -ENODEV; + +} + +static int ddcb_queue_initialized(struct ddcb_queue *queue) +{ + return queue->ddcb_vaddr != NULL; +} + +static void free_ddcb_queue(struct genwqe_dev *cd, struct ddcb_queue *queue) +{ + unsigned int queue_size; + + queue_size = roundup(queue->ddcb_max * sizeof(struct ddcb), PAGE_SIZE); + + kfree(queue->ddcb_req); + queue->ddcb_req = NULL; + + if (queue->ddcb_vaddr) { + __genwqe_free_consistent(cd, queue_size, queue->ddcb_vaddr, + queue->ddcb_daddr); + queue->ddcb_vaddr = NULL; + queue->ddcb_daddr = 0ull; + } +} + +static irqreturn_t genwqe_pf_isr(int irq, void *dev_id) +{ + u64 gfir; + struct genwqe_dev *cd = (struct genwqe_dev *)dev_id; + struct pci_dev *pci_dev = cd->pci_dev; + + /* + * In case of fatal FIR error the queue is stopped, such that + * we can safely check it without risking anything. + */ + cd->irqs_processed++; + wake_up_interruptible(&cd->queue_waitq); + + /* + * Checking for errors before kicking the queue might be + * safer, but slower for the good-case ... See above. + */ + gfir = __genwqe_readq(cd, IO_SLC_CFGREG_GFIR); + if (((gfir & GFIR_ERR_TRIGGER) != 0x0) && + !pci_channel_offline(pci_dev)) { + + if (cd->use_platform_recovery) { + /* + * Since we use raw accessors, EEH errors won't be + * detected by the platform until we do a non-raw + * MMIO or config space read + */ + readq(cd->mmio + IO_SLC_CFGREG_GFIR); + + /* Don't do anything if the PCI channel is frozen */ + if (pci_channel_offline(pci_dev)) + goto exit; + } + + wake_up_interruptible(&cd->health_waitq); + + /* + * By default GFIRs causes recovery actions. This + * count is just for debug when recovery is masked. + */ + dev_err_ratelimited(&pci_dev->dev, + "[%s] GFIR=%016llx\n", + __func__, gfir); + } + + exit: + return IRQ_HANDLED; +} + +static irqreturn_t genwqe_vf_isr(int irq, void *dev_id) +{ + struct genwqe_dev *cd = (struct genwqe_dev *)dev_id; + + cd->irqs_processed++; + wake_up_interruptible(&cd->queue_waitq); + + return IRQ_HANDLED; +} + +/** + * genwqe_card_thread() - Work thread for the DDCB queue + * + * The idea is to check if there are DDCBs in processing. If there are + * some finished DDCBs, we process them and wakeup the + * requestors. Otherwise we give other processes time using + * cond_resched(). + */ +static int genwqe_card_thread(void *data) +{ + int should_stop = 0, rc = 0; + struct genwqe_dev *cd = (struct genwqe_dev *)data; + + while (!kthread_should_stop()) { + + genwqe_check_ddcb_queue(cd, &cd->queue); + + if (GENWQE_POLLING_ENABLED) { + rc = wait_event_interruptible_timeout( + cd->queue_waitq, + genwqe_ddcbs_in_flight(cd) || + (should_stop = kthread_should_stop()), 1); + } else { + rc = wait_event_interruptible_timeout( + cd->queue_waitq, + genwqe_next_ddcb_ready(cd) || + (should_stop = kthread_should_stop()), HZ); + } + if (should_stop) + break; + + /* + * Avoid soft lockups on heavy loads; we do not want + * to disable our interrupts. + */ + cond_resched(); + } + return 0; +} + +/** + * genwqe_setup_service_layer() - Setup DDCB queue + * @cd: pointer to genwqe device descriptor + * + * Allocate DDCBs. Configure Service Layer Controller (SLC). + * + * Return: 0 success + */ +int genwqe_setup_service_layer(struct genwqe_dev *cd) +{ + int rc; + struct ddcb_queue *queue; + struct pci_dev *pci_dev = cd->pci_dev; + + if (genwqe_is_privileged(cd)) { + rc = genwqe_card_reset(cd); + if (rc < 0) { + dev_err(&pci_dev->dev, + "[%s] err: reset failed.\n", __func__); + return rc; + } + genwqe_read_softreset(cd); + } + + queue = &cd->queue; + queue->IO_QUEUE_CONFIG = IO_SLC_QUEUE_CONFIG; + queue->IO_QUEUE_STATUS = IO_SLC_QUEUE_STATUS; + queue->IO_QUEUE_SEGMENT = IO_SLC_QUEUE_SEGMENT; + queue->IO_QUEUE_INITSQN = IO_SLC_QUEUE_INITSQN; + queue->IO_QUEUE_OFFSET = IO_SLC_QUEUE_OFFSET; + queue->IO_QUEUE_WRAP = IO_SLC_QUEUE_WRAP; + queue->IO_QUEUE_WTIME = IO_SLC_QUEUE_WTIME; + queue->IO_QUEUE_ERRCNTS = IO_SLC_QUEUE_ERRCNTS; + queue->IO_QUEUE_LRW = IO_SLC_QUEUE_LRW; + + rc = setup_ddcb_queue(cd, queue); + if (rc != 0) { + rc = -ENODEV; + goto err_out; + } + + init_waitqueue_head(&cd->queue_waitq); + cd->card_thread = kthread_run(genwqe_card_thread, cd, + GENWQE_DEVNAME "%d_thread", + cd->card_idx); + if (IS_ERR(cd->card_thread)) { + rc = PTR_ERR(cd->card_thread); + cd->card_thread = NULL; + goto stop_free_queue; + } + + rc = genwqe_set_interrupt_capability(cd, GENWQE_MSI_IRQS); + if (rc) + goto stop_kthread; + + /* + * We must have all wait-queues initialized when we enable the + * interrupts. Otherwise we might crash if we get an early + * irq. + */ + init_waitqueue_head(&cd->health_waitq); + + if (genwqe_is_privileged(cd)) { + rc = request_irq(pci_dev->irq, genwqe_pf_isr, IRQF_SHARED, + GENWQE_DEVNAME, cd); + } else { + rc = request_irq(pci_dev->irq, genwqe_vf_isr, IRQF_SHARED, + GENWQE_DEVNAME, cd); + } + if (rc < 0) { + dev_err(&pci_dev->dev, "irq %d not free.\n", pci_dev->irq); + goto stop_irq_cap; + } + + cd->card_state = GENWQE_CARD_USED; + return 0; + + stop_irq_cap: + genwqe_reset_interrupt_capability(cd); + stop_kthread: + kthread_stop(cd->card_thread); + cd->card_thread = NULL; + stop_free_queue: + free_ddcb_queue(cd, queue); + err_out: + return rc; +} + +/** + * queue_wake_up_all() - Handles fatal error case + * + * The PCI device got unusable and we have to stop all pending + * requests as fast as we can. The code after this must purge the + * DDCBs in question and ensure that all mappings are freed. + */ +static int queue_wake_up_all(struct genwqe_dev *cd) +{ + unsigned int i; + unsigned long flags; + struct ddcb_queue *queue = &cd->queue; + + spin_lock_irqsave(&queue->ddcb_lock, flags); + + for (i = 0; i < queue->ddcb_max; i++) + wake_up_interruptible(&queue->ddcb_waitqs[queue->ddcb_act]); + + wake_up_interruptible(&queue->busy_waitq); + spin_unlock_irqrestore(&queue->ddcb_lock, flags); + + return 0; +} + +/** + * genwqe_finish_queue() - Remove any genwqe devices and user-interfaces + * + * Relies on the pre-condition that there are no users of the card + * device anymore e.g. with open file-descriptors. + * + * This function must be robust enough to be called twice. + */ +int genwqe_finish_queue(struct genwqe_dev *cd) +{ + int i, rc = 0, in_flight; + int waitmax = GENWQE_DDCB_SOFTWARE_TIMEOUT; + struct pci_dev *pci_dev = cd->pci_dev; + struct ddcb_queue *queue = &cd->queue; + + if (!ddcb_queue_initialized(queue)) + return 0; + + /* Do not wipe out the error state. */ + if (cd->card_state == GENWQE_CARD_USED) + cd->card_state = GENWQE_CARD_UNUSED; + + /* Wake up all requests in the DDCB queue such that they + should be removed nicely. */ + queue_wake_up_all(cd); + + /* We must wait to get rid of the DDCBs in flight */ + for (i = 0; i < waitmax; i++) { + in_flight = genwqe_ddcbs_in_flight(cd); + + if (in_flight == 0) + break; + + dev_dbg(&pci_dev->dev, + " DEBUG [%d/%d] waiting for queue to get empty: %d requests!\n", + i, waitmax, in_flight); + + /* + * Severe severe error situation: The card itself has + * 16 DDCB queues, each queue has e.g. 32 entries, + * each DDBC has a hardware timeout of currently 250 + * msec but the PFs have a hardware timeout of 8 sec + * ... so I take something large. + */ + msleep(1000); + } + if (i == waitmax) { + dev_err(&pci_dev->dev, " [%s] err: queue is not empty!!\n", + __func__); + rc = -EIO; + } + return rc; +} + +/** + * genwqe_release_service_layer() - Shutdown DDCB queue + * @cd: genwqe device descriptor + * + * This function must be robust enough to be called twice. + */ +int genwqe_release_service_layer(struct genwqe_dev *cd) +{ + struct pci_dev *pci_dev = cd->pci_dev; + + if (!ddcb_queue_initialized(&cd->queue)) + return 1; + + free_irq(pci_dev->irq, cd); + genwqe_reset_interrupt_capability(cd); + + if (cd->card_thread != NULL) { + kthread_stop(cd->card_thread); + cd->card_thread = NULL; + } + + free_ddcb_queue(cd, &cd->queue); + return 0; +} |