[3.8.y.z extended stable] Patch "ioatdma: channel reset scheme fixup on Intel Atom S1200 platforms" has been added to staging queue

[Kamal Mostafa]

On Thu, 2014-03-27 at 15:12 -0700, Kamal Mostafa wrote:
> This is a note to let you know that I have just added a patch titled
> 
>     ioatdma: channel reset scheme fixup on Intel Atom S1200 platforms
> 
> to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree 

For the record:  I have dropped Tim Gardner's backport of this one from
the 3.8-stable queue, and picked up Ben Hutchings' backport of "ioat:
fix tasklet tear down" instead.

 -Kamal


> which can be found at:
> 
>  http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue
> 
> This patch is scheduled to be released in version 3.8.13.21.
> 
> If you, or anyone else, feels it should not be added to this tree, please 
> reply to this email.
> 
> For more information about the 3.8.y.z tree, see
> https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable
> 
> Thanks.
> -Kamal
> 
> ------
> 
> From 4d61ec9b5c2b41d853f7afae7611acec2e276fc6 Mon Sep 17 00:00:00 2001
> From: Dave Jiang <dave.jiang at intel.com>
> Date: Tue, 26 Mar 2013 15:42:47 -0700
> Subject: ioatdma: channel reset scheme fixup on Intel Atom S1200 platforms
> 
> commit 8a52b9ff1154a68b6a2a8da9a31a87e52f5f6418 upstream.
> 
> BugLink: http://bugs.launchpad.net/bugs/1291113
> 
> The Intel Atom S1200 family ioatdma changed the channel reset behavior.
> It does a reset similar to PCI FLR by resetting all the MSIX
> registers. We have to re-init msix interrupts because of this. This
> workaround is only specific to this platform and is not expected to carry
> over to the later generations.
> 
> Signed-off-by: Dave Jiang <dave.jiang at intel.com>
> Acked-by: Dan Williams <djbw at fb.com>
> Signed-off-by: Vinod Koul <vinod.koul at intel.com>
> (back ported from commit 8a52b9ff1154a68b6a2a8da9a31a87e52f5f6418)
> 
> [Tim Gardner] Back port notes: I implemented enough of this patch to support
> device->irq_mode storage, upon which da87ca4d4ca101f177fffd84f1f0a5e4c0343557
> (ioat: fix tasklet tear down) is dependent.
> 
> Signed-off-by: Tim Gardner <tim.gardner at canonical.com>
> Signed-off-by: Kamal Mostafa <kamal at canonical.com>
> ---
>  drivers/dma/ioat/dma.c |  8 +++++++-
>  drivers/dma/ioat/dma.h | 10 ++++++++++
>  2 files changed, 17 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/dma/ioat/dma.c b/drivers/dma/ioat/dma.c
> index 1a68a8b..459e2ee 100644
> --- a/drivers/dma/ioat/dma.c
> +++ b/drivers/dma/ioat/dma.c
> @@ -889,7 +889,7 @@ MODULE_PARM_DESC(ioat_interrupt_style,
>   * ioat_dma_setup_interrupts - setup interrupt handler
>   * @device: ioat device
>   */
> -static int ioat_dma_setup_interrupts(struct ioatdma_device *device)
> +int ioat_dma_setup_interrupts(struct ioatdma_device *device)
>  {
>  	struct ioat_chan_common *chan;
>  	struct pci_dev *pdev = device->pdev;
> @@ -938,6 +938,7 @@ msix:
>  		}
>  	}
>  	intrctrl |= IOAT_INTRCTRL_MSIX_VECTOR_CONTROL;
> +	device->irq_mode = IOAT_MSIX;
>  	goto done;
> 
>  msix_single_vector:
> @@ -953,6 +954,7 @@ msix_single_vector:
>  		pci_disable_msix(pdev);
>  		goto msi;
>  	}
> +	device->irq_mode = IOAT_MSIX_SINGLE;
>  	goto done;
> 
>  msi:
> @@ -966,6 +968,7 @@ msi:
>  		pci_disable_msi(pdev);
>  		goto intx;
>  	}
> +	device->irq_mode = IOAT_MSIX;
>  	goto done;
> 
>  intx:
> @@ -974,6 +977,7 @@ intx:
>  	if (err)
>  		goto err_no_irq;
> 
> +	device->irq_mode = IOAT_INTX;
>  done:
>  	if (device->intr_quirk)
>  		device->intr_quirk(device);
> @@ -984,9 +988,11 @@ done:
>  err_no_irq:
>  	/* Disable all interrupt generation */
>  	writeb(0, device->reg_base + IOAT_INTRCTRL_OFFSET);
> +	device->irq_mode = IOAT_NOIRQ;
>  	dev_err(dev, "no usable interrupts\n");
>  	return err;
>  }
> +EXPORT_SYMBOL(ioat_dma_setup_interrupts);
> 
>  static void ioat_disable_interrupts(struct ioatdma_device *device)
>  {
> diff --git a/drivers/dma/ioat/dma.h b/drivers/dma/ioat/dma.h
> index 087935f..84f91ce 100644
> --- a/drivers/dma/ioat/dma.h
> +++ b/drivers/dma/ioat/dma.h
> @@ -48,6 +48,14 @@
>   */
>  #define NULL_DESC_BUFFER_SIZE 1
> 
> +enum ioat_irq_mode {
> +	IOAT_NOIRQ = 0,
> +	IOAT_MSIX,
> +	IOAT_MSIX_SINGLE,
> +	IOAT_MSI,
> +	IOAT_INTX
> +};
> +
>  /**
>   * struct ioatdma_device - internal representation of a IOAT device
>   * @pdev: PCI-Express device
> @@ -77,6 +85,7 @@ struct ioatdma_device {
>  	struct msix_entry msix_entries[4];
>  	struct ioat_chan_common *idx[4];
>  	struct dca_provider *dca;
> +	enum ioat_irq_mode irq_mode;
>  	void (*intr_quirk)(struct ioatdma_device *device);
>  	int (*enumerate_channels)(struct ioatdma_device *device);
>  	int (*reset_hw)(struct ioat_chan_common *chan);
> @@ -320,6 +329,7 @@ bool ioat_cleanup_preamble(struct ioat_chan_common *chan,
>  			   dma_addr_t *phys_complete);
>  void ioat_kobject_add(struct ioatdma_device *device, struct kobj_type *type);
>  void ioat_kobject_del(struct ioatdma_device *device);
> +int ioat_dma_setup_interrupts(struct ioatdma_device *device);
>  extern const struct sysfs_ops ioat_sysfs_ops;
>  extern struct ioat_sysfs_entry ioat_version_attr;
>  extern struct ioat_sysfs_entry ioat_cap_attr;
> --
> 1.8.3.2
>