On Fri, 19 Nov 2021 16:02:30 -0800
Ben Widawsky <ben.widawsky@xxxxxxxxx> wrote:
> The Memory Device Status register is inspected in the same way for at
> least two flows in the CXL Type 3 Memory Device Software Guide
> (Revision: 1.0): 2.13.9 Device discovery and mailbox ready sequence,
> and 2.13.10 Media ready sequence. Extract this common functionality for
> use by both.
>
> Signed-off-by: Ben Widawsky <ben.widawsky@xxxxxxxxx>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
> ---
> This patch did not exist in RFCv2
> ---
> drivers/cxl/pci.c | 33 +++++++++++++++++++++++++--------
> 1 file changed, 25 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c
> index a6ea9811a05b..6c8d09fb3a17 100644
> --- a/drivers/cxl/pci.c
> +++ b/drivers/cxl/pci.c
> @@ -182,6 +182,27 @@ static int __cxl_pci_mbox_send_cmd(struct cxl_dev_state *cxlds,
> return 0;
> }
>
> +/*
> + * Implements roughly the bottom half of Figure 42 of the CXL Type 3 Memory
> + * Device Software Guide
> + */
> +static int check_device_status(struct cxl_dev_state *cxlds)
> +{
> + const u64 md_status = readq(cxlds->regs.memdev + CXLMDEV_STATUS_OFFSET);
> +
> + if (md_status & CXLMDEV_DEV_FATAL) {
> + dev_err(cxlds->dev, "Fatal: replace device\n");
> + return -EIO;
> + }
> +
> + if (md_status & CXLMDEV_FW_HALT) {
> + dev_err(cxlds->dev, "FWHalt: reset or replace device\n");
> + return -EBUSY;
> + }
> +
> + return 0;
> +}
> +
> /**
> * cxl_pci_mbox_get() - Acquire exclusive access to the mailbox.
> * @cxlds: The device state to gain access to.
> @@ -231,17 +252,13 @@ static int cxl_pci_mbox_get(struct cxl_dev_state *cxlds)
> * Hardware shouldn't allow a ready status but also have failure bits
> * set. Spit out an error, this should be a bug report
> */
> - rc = -EFAULT;
> - if (md_status & CXLMDEV_DEV_FATAL) {
> - dev_err(dev, "mbox: reported ready, but fatal\n");
> + rc = check_device_status(cxlds);
> + if (rc)
> goto out;
> - }
> - if (md_status & CXLMDEV_FW_HALT) {
> - dev_err(dev, "mbox: reported ready, but halted\n");
> - goto out;
> - }
> +
> if (CXLMDEV_RESET_NEEDED(md_status)) {
> dev_err(dev, "mbox: reported ready, but reset needed\n");
> + rc = -EFAULT;
> goto out;
> }
>
