Re: [PATCH v5 09/16] cxl/pci: Map CXL PCIe Upstream Switch Port RAS registers

Ira Weiny
2025-01-14T22:03:11Z

Terry Bowman wrote:
> Add logic to map CXL PCIe Upstream Switch Port (USP) RAS registers.
>
> Introduce 'struct cxl_regs' member into 'struct cxl_port' to cache a
> pointer to the CXL Upstream Port's mapped RAS registers.
>
> Also, introduce cxl_uport_init_ras_reporting() to perform the USP RAS
> register mapping. This is similar to the existing
> cxl_dport_init_ras_reporting() but for USP devices.
>
> The USP may have multiple downstream endpoints. Before mapping AER
> registers check if the registers are already mapped.
>
> Signed-off-by: Terry Bowman <terry.bowman@amd.com>
> ---
> drivers/cxl/core/pci.c | 15 +++++++++++++++
> drivers/cxl/cxl.h | 4 ++++
> drivers/cxl/mem.c | 8 ++++++++
> 3 files changed, 27 insertions(+)
>
> diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c
> index 1af2d0a14f5d..97e6a15bea88 100644
> --- a/drivers/cxl/core/pci.c
> +++ b/drivers/cxl/core/pci.c
> @@ -773,6 +773,21 @@ static void cxl_disable_rch_root_ints(struct cxl_dport *dport)
> writel(aer_cmd, aer_base + PCI_ERR_ROOT_COMMAND);
> }
>
> +void cxl_uport_init_ras_reporting(struct cxl_port *port)
> +{
> + /* uport may have more than 1 downstream EP. Check if already mapped. */
> + if (port->uport_regs.ras)
> + return;
> +
> + port->reg_map.host = &port->dev;
> + if (cxl_map_component_regs(&port->reg_map, &port->uport_regs,
> + BIT(CXL_CM_CAP_CAP_ID_RAS))) {
> + dev_err(&port->dev, "Failed to map RAS capability.\n");
> + return;

Why return here? Actually I think 8/16 had the same issue now that I see
this.

Other than that:

Reviewed-by: Ira Weiny <ira.weiny@intel.com>

[snip]