RE: [PATCH 22.11] event/dlb2: fix disable PASID

["Xueming(Steven) Li" <xuemingl@nvidia.com>]

> -----Original Message-----
> From: Abdullah Sevincer <abdullah.sevincer@intel.com>
> Sent: 11/10/2023 3:46
> To: stable@dpdk.org
> Cc: Abdullah Sevincer <abdullah.sevincer@intel.com>
> Subject: [PATCH 22.11] event/dlb2: fix disable PASID
> 
> [ upstream commit 5a6878335b8179337ec2d9931debf1f46525e8fc ]
> 
> In vfio-pci driver when PASID is enabled by default DLB hardware puts DLB in
> SIOV mode. This breaks DLB PF-PMD mode. For DLB PF-PMD mode to function
> properly PASID needs to be disabled.
> 
> In this commit this issue is addressed and PASID is disabled by writing a zero to
> PASID control register.
> 
> Fixes: 5433956d5185 ("event/dlb2: add eventdev probe")
> 
> Signed-off-by: Abdullah Sevincer <abdullah.sevincer@intel.com>
> ---
>  drivers/event/dlb2/pf/dlb2_main.c | 27 +++++++++++++++++++++++++++
>  1 file changed, 27 insertions(+)
> 
> diff --git a/drivers/event/dlb2/pf/dlb2_main.c
> b/drivers/event/dlb2/pf/dlb2_main.c
> index 717aa4fc08..63868e2388 100644
> --- a/drivers/event/dlb2/pf/dlb2_main.c
> +++ b/drivers/event/dlb2/pf/dlb2_main.c
> @@ -46,6 +46,7 @@
>  #define DLB2_PCI_CAP_ID_MSIX      0x11
>  #define DLB2_PCI_EXT_CAP_ID_PRI   0x13
>  #define DLB2_PCI_EXT_CAP_ID_ACS   0xD
> +#define DLB2_PCI_EXT_CAP_ID_PASID 0x1B	/* Process Address Space ID */
> 
>  #define DLB2_PCI_PRI_CTRL_ENABLE         0x1
>  #define DLB2_PCI_PRI_ALLOC_REQ           0xC
> @@ -64,6 +65,8 @@
>  #define DLB2_PCI_ACS_CR                  0x8
>  #define DLB2_PCI_ACS_UF                  0x10
>  #define DLB2_PCI_ACS_EC                  0x20
> +#define DLB2_PCI_PASID_CTRL              0x06    /* PASID control register */
> +#define DLB2_PCI_PASID_CAP_OFFSET        0x148   /* PASID capability offset */
> 
>  static int dlb2_pci_find_capability(struct rte_pci_device *pdev, uint32_t id)
> { @@ -257,12 +260,14 @@ dlb2_pf_reset(struct dlb2_dev *dlb2_dev)
>  	uint16_t rt_ctl_word;
>  	uint32_t pri_reqs_dword;
>  	uint16_t pri_ctrl_word;
> +	uint16_t pasid_ctrl;
> 
>  	int pcie_cap_offset;
>  	int pri_cap_offset;
>  	int msix_cap_offset;
>  	int err_cap_offset;
>  	int acs_cap_offset;
> +	int pasid_cap_offset;
>  	int wait_count;
> 
>  	uint16_t devsta_busy_word;
> @@ -582,6 +587,28 @@ dlb2_pf_reset(struct dlb2_dev *dlb2_dev)
>  		}
>  	}
> 
> +	/* The current Linux kernel vfio driver does not expose PASID capability
> to
> +	 * users. It also enables PASID by default, which breaks DLB PF PMD. We
> have
> +	 * to use the hardcoded offset for now to disable PASID.
> +	 */
> +	pasid_cap_offset = DLB2_PCI_PASID_CAP_OFFSET;
> +
> +	off = pasid_cap_offset + DLB2_PCI_PASID_CTRL;
> +	if (rte_pci_read_config(pdev, &pasid_ctrl, 2, off) != 2)
> +		pasid_ctrl = 0;
> +
> +	if (pasid_ctrl) {
> +		DLB2_INFO(dlb2_dev, "DLB2 disabling pasid...\n");
> +
> +		pasid_ctrl = 0;
> +		ret = rte_pci_write_config(pdev, &pasid_ctrl, 2, off);
> +		if (ret != 2) {
> +			DLB2_LOG_ERR("[%s()] failed to write the pcie config
> space at offset %d\n",
> +				__func__, (int)off);
> +			return ret;
> +		}
> +	}
> +
>  	return 0;
>  }
> 
> --
> 2.39.1.windows.1

Applied to 22.11 branch, thanks for backporting!