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Message-ID: <20110802191902.GA27723@beardog.cce.hp.com>
Date: Tue, 2 Aug 2011 14:19:02 -0500
From: scameron@...rdog.cce.hp.com
To: Joe Handzik <joseph.t.handzik@...rdog.cce.hp.com>
Cc: axboe@...nel.dk, linux-kernel@...r.kernel.org,
stephenmcameron@...il.com, akpm@...ux-foundation.org,
mikem@...rdog.cce.hp.com, thenzl@...hat.com
Subject: Re: [PATCH 1/2] cciss: Adds simple mode functionality
On Wed, Jul 27, 2011 at 04:38:30PM -0500, Joe Handzik wrote:
> From: Joseph Handzik <joseph.t.handzik@...rdog.cce.hp.com>
>
> Signed-off-by: Joseph Handzik <joseph.t.handzik@...rdog.cce.hp.com>
Looks ok to me. Ack.
-- steve
> ---
> Documentation/blockdev/cciss.txt | 10 +++++++
> drivers/block/cciss.c | 56 +++++++++++++++++++++++++++++++-------
> drivers/block/cciss.h | 1 +
> 3 files changed, 56 insertions(+), 11 deletions(-)
>
> diff --git a/Documentation/blockdev/cciss.txt b/Documentation/blockdev/cciss.txt
> index c00c6a5..71464e0 100644
> --- a/Documentation/blockdev/cciss.txt
> +++ b/Documentation/blockdev/cciss.txt
> @@ -78,6 +78,16 @@ The device naming scheme is:
> /dev/cciss/c1d1p2 Controller 1, disk 1, partition 2
> /dev/cciss/c1d1p3 Controller 1, disk 1, partition 3
>
> +CCISS simple mode support
> +-------------------------
> +
> +The "cciss_simple_mode=1" boot parameter may be used to prevent the driver
> +from putting the controller into "performant" mode. The difference is that
> +with simple mode, each command completion requires an interrupt, while with
> +"performant mode" (the default, and ordinarily better performing) it is
> +possible to have multiple command completions indicated by a single
> +interrupt.
> +
> SCSI tape drive and medium changer support
> ------------------------------------------
>
> diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c
> index 8f4ef65..61f0b5b 100644
> --- a/drivers/block/cciss.c
> +++ b/drivers/block/cciss.c
> @@ -68,6 +68,10 @@ static int cciss_tape_cmds = 6;
> module_param(cciss_tape_cmds, int, 0644);
> MODULE_PARM_DESC(cciss_tape_cmds,
> "number of commands to allocate for tape devices (default: 6)");
> +static int cciss_simple_mode;
> +module_param(cciss_simple_mode, int, S_IRUGO|S_IWUSR);
> +MODULE_PARM_DESC(cciss_simple_mode,
> + "Use 'simple mode' rather than 'performant mode'");
>
> static DEFINE_MUTEX(cciss_mutex);
> static struct proc_dir_entry *proc_cciss;
> @@ -176,6 +180,7 @@ static void cciss_geometry_inquiry(ctlr_info_t *h, int logvol,
> unsigned int block_size, InquiryData_struct *inq_buff,
> drive_info_struct *drv);
> static void __devinit cciss_interrupt_mode(ctlr_info_t *);
> +static int __devinit cciss_enter_simple_mode(struct ctlr_info *h);
> static void start_io(ctlr_info_t *h);
> static int sendcmd_withirq(ctlr_info_t *h, __u8 cmd, void *buff, size_t size,
> __u8 page_code, unsigned char scsi3addr[],
> @@ -388,7 +393,7 @@ static void cciss_seq_show_header(struct seq_file *seq)
> h->product_name,
> (unsigned long)h->board_id,
> h->firm_ver[0], h->firm_ver[1], h->firm_ver[2],
> - h->firm_ver[3], (unsigned int)h->intr[PERF_MODE_INT],
> + h->firm_ver[3], (unsigned int)h->intr[h->intr_mode],
> h->num_luns,
> h->Qdepth, h->commands_outstanding,
> h->maxQsinceinit, h->max_outstanding, h->maxSG);
> @@ -3984,6 +3989,9 @@ static void __devinit cciss_put_controller_into_performant_mode(ctlr_info_t *h)
> {
> __u32 trans_support;
>
> + if (cciss_simple_mode)
> + return;
> +
> dev_dbg(&h->pdev->dev, "Trying to put board into Performant mode\n");
> /* Attempt to put controller into performant mode if supported */
> /* Does board support performant mode? */
> @@ -4081,7 +4089,7 @@ static void __devinit cciss_interrupt_mode(ctlr_info_t *h)
> default_int_mode:
> #endif /* CONFIG_PCI_MSI */
> /* if we get here we're going to use the default interrupt mode */
> - h->intr[PERF_MODE_INT] = h->pdev->irq;
> + h->intr[h->intr_mode] = h->pdev->irq;
> return;
> }
>
> @@ -4341,6 +4349,9 @@ static int __devinit cciss_pci_init(ctlr_info_t *h)
> }
> cciss_enable_scsi_prefetch(h);
> cciss_p600_dma_prefetch_quirk(h);
> + err = cciss_enter_simple_mode(h);
> + if (err)
> + goto err_out_free_res;
> cciss_put_controller_into_performant_mode(h);
> return 0;
>
> @@ -4843,20 +4854,20 @@ static int cciss_request_irq(ctlr_info_t *h,
> irqreturn_t (*intxhandler)(int, void *))
> {
> if (h->msix_vector || h->msi_vector) {
> - if (!request_irq(h->intr[PERF_MODE_INT], msixhandler,
> + if (!request_irq(h->intr[h->intr_mode], msixhandler,
> IRQF_DISABLED, h->devname, h))
> return 0;
> dev_err(&h->pdev->dev, "Unable to get msi irq %d"
> - " for %s\n", h->intr[PERF_MODE_INT],
> + " for %s\n", h->intr[h->intr_mode],
> h->devname);
> return -1;
> }
>
> - if (!request_irq(h->intr[PERF_MODE_INT], intxhandler,
> + if (!request_irq(h->intr[h->intr_mode], intxhandler,
> IRQF_DISABLED, h->devname, h))
> return 0;
> dev_err(&h->pdev->dev, "Unable to get irq %d for %s\n",
> - h->intr[PERF_MODE_INT], h->devname);
> + h->intr[h->intr_mode], h->devname);
> return -1;
> }
>
> @@ -4887,7 +4898,7 @@ static void cciss_undo_allocations_after_kdump_soft_reset(ctlr_info_t *h)
> {
> int ctlr = h->ctlr;
>
> - free_irq(h->intr[PERF_MODE_INT], h);
> + free_irq(h->intr[h->intr_mode], h);
> #ifdef CONFIG_PCI_MSI
> if (h->msix_vector)
> pci_disable_msix(h->pdev);
> @@ -4953,6 +4964,7 @@ reinit_after_soft_reset:
> h = hba[i];
> h->pdev = pdev;
> h->busy_initializing = 1;
> + h->intr_mode = cciss_simple_mode ? SIMPLE_MODE_INT : PERF_MODE_INT;
> INIT_LIST_HEAD(&h->cmpQ);
> INIT_LIST_HEAD(&h->reqQ);
> mutex_init(&h->busy_shutting_down);
> @@ -5009,7 +5021,7 @@ reinit_after_soft_reset:
>
> dev_info(&h->pdev->dev, "%s: <0x%x> at PCI %s IRQ %d%s using DAC\n",
> h->devname, pdev->device, pci_name(pdev),
> - h->intr[PERF_MODE_INT], dac ? "" : " not");
> + h->intr[h->intr_mode], dac ? "" : " not");
>
> if (cciss_allocate_cmd_pool(h))
> goto clean4;
> @@ -5056,7 +5068,7 @@ reinit_after_soft_reset:
> spin_lock_irqsave(&h->lock, flags);
> h->access.set_intr_mask(h, CCISS_INTR_OFF);
> spin_unlock_irqrestore(&h->lock, flags);
> - free_irq(h->intr[PERF_MODE_INT], h);
> + free_irq(h->intr[h->intr_mode], h);
> rc = cciss_request_irq(h, cciss_msix_discard_completions,
> cciss_intx_discard_completions);
> if (rc) {
> @@ -5133,7 +5145,7 @@ clean4:
> cciss_free_cmd_pool(h);
> cciss_free_scatterlists(h);
> cciss_free_sg_chain_blocks(h->cmd_sg_list, h->nr_cmds);
> - free_irq(h->intr[PERF_MODE_INT], h);
> + free_irq(h->intr[h->intr_mode], h);
> clean2:
> unregister_blkdev(h->major, h->devname);
> clean1:
> @@ -5172,9 +5184,31 @@ static void cciss_shutdown(struct pci_dev *pdev)
> if (return_code != IO_OK)
> dev_warn(&h->pdev->dev, "Error flushing cache\n");
> h->access.set_intr_mask(h, CCISS_INTR_OFF);
> - free_irq(h->intr[PERF_MODE_INT], h);
> + free_irq(h->intr[h->intr_mode], h);
> }
>
> +static int __devinit cciss_enter_simple_mode(struct ctlr_info *h)
> +{
> + u32 trans_support;
> +
> + trans_support = readl(&(h->cfgtable->TransportSupport));
> + if (!(trans_support & SIMPLE_MODE))
> + return -ENOTSUPP;
> +
> + h->max_commands = readl(&(h->cfgtable->CmdsOutMax));
> + writel(CFGTBL_Trans_Simple, &(h->cfgtable->HostWrite.TransportRequest));
> + writel(CFGTBL_ChangeReq, h->vaddr + SA5_DOORBELL);
> + cciss_wait_for_mode_change_ack(h);
> + print_cfg_table(h);
> + if (!(readl(&(h->cfgtable->TransportActive)) & CFGTBL_Trans_Simple)) {
> + dev_warn(&h->pdev->dev, "unable to get board into simple mode\n");
> + return -ENODEV;
> + }
> + h->transMethod = CFGTBL_Trans_Simple;
> + return 0;
> +}
> +
> +
> static void __devexit cciss_remove_one(struct pci_dev *pdev)
> {
> ctlr_info_t *h;
> diff --git a/drivers/block/cciss.h b/drivers/block/cciss.h
> index 16b4d58..166fcd0 100644
> --- a/drivers/block/cciss.h
> +++ b/drivers/block/cciss.h
> @@ -92,6 +92,7 @@ struct ctlr_info
> unsigned int intr[4];
> unsigned int msix_vector;
> unsigned int msi_vector;
> + int intr_mode;
> int cciss_max_sectors;
> BYTE cciss_read;
> BYTE cciss_write;
--
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