[U-Boot] [PATCH] nvme: use page-aligned buffer for identify command

[Bin Meng]

On Mon, Oct 14, 2019 at 7:10 PM Patrick Wildt <patrick at blueri.se> wrote:
>
> Change the stack-allocated buffer for the identification command
> to explicitly allocate page-aligned buffers.  Even though the spec
> seems to allow having admin queue commands on non page-aligned
> buffers, it seems to not be possible on my i.MX8MQ board with a
> a Silicon Power P34A80.  Since all of the NVMe drivers I have seen
> always do admin commands on a page-aligned buffer, which does work
> on my system, it makes sense for us to do that as well.
>
> Signed-off-by: Patrick Wildt <patrick at blueri.se>
> ---
>  drivers/nvme/nvme.c | 24 ++++++++++++++++++------
>  1 file changed, 18 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/nvme/nvme.c b/drivers/nvme/nvme.c
> index ee6b581d9e..2444e0270f 100644
> --- a/drivers/nvme/nvme.c
> +++ b/drivers/nvme/nvme.c
> @@ -580,14 +580,19 @@ static int nvme_setup_io_queues(struct nvme_dev *dev)
>
>  static int nvme_get_info_from_identify(struct nvme_dev *dev)
>  {
> -       ALLOC_CACHE_ALIGN_BUFFER(char, buf, sizeof(struct nvme_id_ctrl));
> -       struct nvme_id_ctrl *ctrl = (struct nvme_id_ctrl *)buf;
> +       struct nvme_id_ctrl *ctrl;
>         int ret;
>         int shift = NVME_CAP_MPSMIN(dev->cap) + 12;
>
> +       ctrl = memalign(4096, sizeof(struct nvme_id_ctrl));

Please use ndev->page_size instead of 4096.

> +       if (!ctrl)
> +               return -ENOMEM;
> +
>         ret = nvme_identify(dev, 0, 1, (dma_addr_t)(long)ctrl);
> -       if (ret)
> +       if (ret) {
> +               free(ctrl);
>                 return -EIO;
> +       }
>
>         dev->nn = le32_to_cpu(ctrl->nn);
>         dev->vwc = ctrl->vwc;
> @@ -618,6 +623,7 @@ static int nvme_get_info_from_identify(struct nvme_dev *dev)
>                 dev->max_transfer_shift = 20;
>         }
>
> +       free(ctrl);
>         return 0;
>  }
>
> @@ -658,16 +664,21 @@ static int nvme_blk_probe(struct udevice *udev)
>         struct blk_desc *desc = dev_get_uclass_platdata(udev);
>         struct nvme_ns *ns = dev_get_priv(udev);
>         u8 flbas;
> -       ALLOC_CACHE_ALIGN_BUFFER(char, buf, sizeof(struct nvme_id_ns));
> -       struct nvme_id_ns *id = (struct nvme_id_ns *)buf;
>         struct pci_child_platdata *pplat;
> +       struct nvme_id_ns *id;
> +
> +       id = memalign(4096, sizeof(struct nvme_id_ns));

ditto

> +       if (!id)
> +               return -ENOMEM;
>
>         memset(ns, 0, sizeof(*ns));
>         ns->dev = ndev;
>         /* extract the namespace id from the block device name */
>         ns->ns_id = trailing_strtol(udev->name) + 1;
> -       if (nvme_identify(ndev, ns->ns_id, 0, (dma_addr_t)(long)id))
> +       if (nvme_identify(ndev, ns->ns_id, 0, (dma_addr_t)(long)id)) {
> +               free(id);
>                 return -EIO;
> +       }
>
>         memcpy(&ns->eui64, &id->eui64, sizeof(id->eui64));
>         flbas = id->flbas & NVME_NS_FLBAS_LBA_MASK;
> @@ -686,6 +697,7 @@ static int nvme_blk_probe(struct udevice *udev)
>         memcpy(desc->product, ndev->serial, sizeof(ndev->serial));
>         memcpy(desc->revision, ndev->firmware_rev, sizeof(ndev->firmware_rev));
>
> +       free(id);
>         return 0;
>  }
>

Regards,
Bin