From 1451f414639465995dfc1f820aa1a64723cbd662 Mon Sep 17 00:00:00 2001 From: Frank Haverkamp Date: Wed, 10 Sep 2014 16:37:53 +0200 Subject: GenWQE: Support blocking when DDCB queue is busy When the GenWQE hardware queue was busy, the driver returned simply -EBUSY. This caused polling by applications which increased the load on the already busy system. This change implements the possiblity to sleep on a waitqueue instead when the DDCB queue is busy. The requestor is woken up when there is free space on the queue again. The old way to get -EBUSY is still available if the device is openend with O_NONBLOCKING. The default is now blocking behavior. Signed-off-by: Frank Haverkamp Signed-off-by: Greg Kroah-Hartman --- drivers/misc/genwqe/card_base.h | 17 +++++++++------ drivers/misc/genwqe/card_ddcb.c | 44 +++++++++++++++++++++++++++++--------- drivers/misc/genwqe/card_debugfs.c | 6 ++++-- drivers/misc/genwqe/card_dev.c | 12 +++++++---- 4 files changed, 57 insertions(+), 22 deletions(-) (limited to 'drivers/misc/genwqe') diff --git a/drivers/misc/genwqe/card_base.h b/drivers/misc/genwqe/card_base.h index b622d204b72b..c64d7cad1085 100644 --- a/drivers/misc/genwqe/card_base.h +++ b/drivers/misc/genwqe/card_base.h @@ -201,7 +201,8 @@ static inline void genwqe_mapping_init(struct dma_mapping *m, * @ddcb_seq: Sequence number of last DDCB * @ddcbs_in_flight: Currently enqueued DDCBs * @ddcbs_completed: Number of already completed DDCBs - * @busy: Number of -EBUSY returns + * @return_on_busy: Number of -EBUSY returns on full queue + * @wait_on_busy: Number of waits on full queue * @ddcb_daddr: DMA address of first DDCB in the queue * @ddcb_vaddr: Kernel virtual address of first DDCB in the queue * @ddcb_req: Associated requests (one per DDCB) @@ -218,7 +219,8 @@ struct ddcb_queue { unsigned int ddcbs_in_flight; /* number of ddcbs in processing */ unsigned int ddcbs_completed; unsigned int ddcbs_max_in_flight; - unsigned int busy; /* how many times -EBUSY? */ + unsigned int return_on_busy; /* how many times -EBUSY? */ + unsigned int wait_on_busy; dma_addr_t ddcb_daddr; /* DMA address */ struct ddcb *ddcb_vaddr; /* kernel virtual addr for DDCBs */ @@ -226,7 +228,7 @@ struct ddcb_queue { wait_queue_head_t *ddcb_waitqs; /* waitqueue per ddcb */ spinlock_t ddcb_lock; /* exclusive access to queue */ - wait_queue_head_t ddcb_waitq; /* wait for ddcb processing */ + wait_queue_head_t busy_waitq; /* wait for ddcb processing */ /* registers or the respective queue to be used */ u32 IO_QUEUE_CONFIG; @@ -508,7 +510,7 @@ static inline bool dma_mapping_used(struct dma_mapping *m) * buildup and teardown. */ int __genwqe_execute_ddcb(struct genwqe_dev *cd, - struct genwqe_ddcb_cmd *cmd); + struct genwqe_ddcb_cmd *cmd, unsigned int f_flags); /** * __genwqe_execute_raw_ddcb() - Execute DDCB request without addr translation @@ -520,9 +522,12 @@ int __genwqe_execute_ddcb(struct genwqe_dev *cd, * modification. */ int __genwqe_execute_raw_ddcb(struct genwqe_dev *cd, - struct genwqe_ddcb_cmd *cmd); + struct genwqe_ddcb_cmd *cmd, + unsigned int f_flags); +int __genwqe_enqueue_ddcb(struct genwqe_dev *cd, + struct ddcb_requ *req, + unsigned int f_flags); -int __genwqe_enqueue_ddcb(struct genwqe_dev *cd, struct ddcb_requ *req); int __genwqe_wait_ddcb(struct genwqe_dev *cd, struct ddcb_requ *req); int __genwqe_purge_ddcb(struct genwqe_dev *cd, struct ddcb_requ *req); diff --git a/drivers/misc/genwqe/card_ddcb.c b/drivers/misc/genwqe/card_ddcb.c index 51480e4f8054..6d51e5f08664 100644 --- a/drivers/misc/genwqe/card_ddcb.c +++ b/drivers/misc/genwqe/card_ddcb.c @@ -448,8 +448,10 @@ static int genwqe_check_ddcb_queue(struct genwqe_dev *cd, queue->ddcbs_completed++; queue->ddcbs_in_flight--; - /* wake up process waiting for this DDCB */ + /* 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; @@ -745,14 +747,16 @@ int genwqe_init_debug_data(struct genwqe_dev *cd, struct genwqe_debug_data *d) /** * __genwqe_enqueue_ddcb() - Enqueue a DDCB - * @cd: pointer to genwqe device descriptor - * @req: pointer to DDCB execution request + * @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) +int __genwqe_enqueue_ddcb(struct genwqe_dev *cd, struct ddcb_requ *req, + unsigned int f_flags) { struct ddcb *pddcb; unsigned long flags; @@ -760,6 +764,7 @@ int __genwqe_enqueue_ddcb(struct genwqe_dev *cd, struct ddcb_requ *req) 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", @@ -785,9 +790,24 @@ int __genwqe_enqueue_ddcb(struct genwqe_dev *cd, struct ddcb_requ *req) pddcb = get_next_ddcb(cd, queue, &req->num); /* get ptr and num */ if (pddcb == NULL) { + int rc; + spin_unlock_irqrestore(&queue->ddcb_lock, flags); - queue->busy++; - return -EBUSY; + + 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) { @@ -890,9 +910,11 @@ int __genwqe_enqueue_ddcb(struct genwqe_dev *cd, struct ddcb_requ *req) * __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) + struct genwqe_ddcb_cmd *cmd, + unsigned int f_flags) { int rc = 0; struct pci_dev *pci_dev = cd->pci_dev; @@ -908,7 +930,7 @@ int __genwqe_execute_raw_ddcb(struct genwqe_dev *cd, __func__, cmd->asiv_length); return -EINVAL; } - rc = __genwqe_enqueue_ddcb(cd, req); + rc = __genwqe_enqueue_ddcb(cd, req, f_flags); if (rc != 0) return rc; @@ -1014,7 +1036,8 @@ static int setup_ddcb_queue(struct genwqe_dev *cd, struct ddcb_queue *queue) queue->ddcbs_in_flight = 0; /* statistics */ queue->ddcbs_max_in_flight = 0; queue->ddcbs_completed = 0; - queue->busy = 0; + queue->return_on_busy = 0; + queue->wait_on_busy = 0; queue->ddcb_seq = 0x100; /* start sequence number */ queue->ddcb_max = genwqe_ddcb_max; /* module parameter */ @@ -1054,7 +1077,7 @@ static int setup_ddcb_queue(struct genwqe_dev *cd, struct ddcb_queue *queue) queue->ddcb_next = 0; /* queue is empty */ spin_lock_init(&queue->ddcb_lock); - init_waitqueue_head(&queue->ddcb_waitq); + init_waitqueue_head(&queue->busy_waitq); val64 = ((u64)(queue->ddcb_max - 1) << 8); /* lastptr */ __genwqe_writeq(cd, queue->IO_QUEUE_CONFIG, 0x07); /* iCRC/vCRC */ @@ -1302,6 +1325,7 @@ static int queue_wake_up_all(struct genwqe_dev *cd) 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; diff --git a/drivers/misc/genwqe/card_debugfs.c b/drivers/misc/genwqe/card_debugfs.c index 40b425d35866..c715534e7fe7 100644 --- a/drivers/misc/genwqe/card_debugfs.c +++ b/drivers/misc/genwqe/card_debugfs.c @@ -244,14 +244,16 @@ static int genwqe_ddcb_info_show(struct seq_file *s, void *unused) " ddcbs_in_flight: %u\n" " ddcbs_max_in_flight: %u\n" " ddcbs_completed: %u\n" - " busy: %u\n" + " return_on_busy: %u\n" + " wait_on_busy: %u\n" " irqs_processed: %u\n", queue->ddcb_max, (long long)queue->ddcb_daddr, (long long)queue->ddcb_daddr + (queue->ddcb_max * DDCB_LENGTH), (long long)queue->ddcb_vaddr, queue->ddcbs_in_flight, queue->ddcbs_max_in_flight, queue->ddcbs_completed, - queue->busy, cd->irqs_processed); + queue->return_on_busy, queue->wait_on_busy, + cd->irqs_processed); /* Hardware State */ seq_printf(s, " 0x%08x 0x%016llx IO_QUEUE_CONFIG\n" diff --git a/drivers/misc/genwqe/card_dev.c b/drivers/misc/genwqe/card_dev.c index 59e0081acc8f..5918586f2f76 100644 --- a/drivers/misc/genwqe/card_dev.c +++ b/drivers/misc/genwqe/card_dev.c @@ -516,6 +516,7 @@ static int do_flash_update(struct genwqe_file *cfile, u32 crc; u8 cmdopts; struct genwqe_dev *cd = cfile->cd; + struct file *filp = cfile->filp; struct pci_dev *pci_dev = cd->pci_dev; if ((load->size & 0x3) != 0) @@ -610,7 +611,7 @@ static int do_flash_update(struct genwqe_file *cfile, /* For Genwqe5 we get back the calculated CRC */ *(u64 *)&req->asv[0] = 0ULL; /* 0x80 */ - rc = __genwqe_execute_raw_ddcb(cd, req); + rc = __genwqe_execute_raw_ddcb(cd, req, filp->f_flags); load->retc = req->retc; load->attn = req->attn; @@ -650,6 +651,7 @@ static int do_flash_read(struct genwqe_file *cfile, u8 *xbuf; u8 cmdopts; struct genwqe_dev *cd = cfile->cd; + struct file *filp = cfile->filp; struct pci_dev *pci_dev = cd->pci_dev; struct genwqe_ddcb_cmd *cmd; @@ -727,7 +729,7 @@ static int do_flash_read(struct genwqe_file *cfile, /* we only get back the calculated CRC */ *(u64 *)&cmd->asv[0] = 0ULL; /* 0x80 */ - rc = __genwqe_execute_raw_ddcb(cd, cmd); + rc = __genwqe_execute_raw_ddcb(cd, cmd, filp->f_flags); load->retc = cmd->retc; load->attn = cmd->attn; @@ -988,13 +990,14 @@ static int genwqe_execute_ddcb(struct genwqe_file *cfile, { int rc; struct genwqe_dev *cd = cfile->cd; + struct file *filp = cfile->filp; struct ddcb_requ *req = container_of(cmd, struct ddcb_requ, cmd); rc = ddcb_cmd_fixups(cfile, req); if (rc != 0) return rc; - rc = __genwqe_execute_raw_ddcb(cd, cmd); + rc = __genwqe_execute_raw_ddcb(cd, cmd, filp->f_flags); ddcb_cmd_cleanup(cfile, req); return rc; } @@ -1006,6 +1009,7 @@ static int do_execute_ddcb(struct genwqe_file *cfile, struct genwqe_ddcb_cmd *cmd; struct ddcb_requ *req; struct genwqe_dev *cd = cfile->cd; + struct file *filp = cfile->filp; cmd = ddcb_requ_alloc(); if (cmd == NULL) @@ -1021,7 +1025,7 @@ static int do_execute_ddcb(struct genwqe_file *cfile, if (!raw) rc = genwqe_execute_ddcb(cfile, cmd); else - rc = __genwqe_execute_raw_ddcb(cd, cmd); + rc = __genwqe_execute_raw_ddcb(cd, cmd, filp->f_flags); /* Copy back only the modifed fields. Do not copy ASIV back since the copy got modified by the driver. */ -- cgit v1.2.3