diff mbox series

[v4,27/40] cxl/pci: Cache device DVSEC offset

Message ID 164375309615.513620.7874131241128599893.stgit@dwillia2-desk3.amr.corp.intel.com
State Accepted
Commit 06e279e5ebe4f32ffe544ec96a199870319a7315
Headers show
Series None | expand

Commit Message

Dan Williams Feb. 1, 2022, 10:06 p.m. UTC
From: Ben Widawsky <ben.widawsky@intel.com>

The PCIe device DVSEC, defined in the CXL 2.0 spec, 8.1.3 is required to
be implemented by CXL 2.0 endpoint devices. In preparation for consuming
this information in a new cxl_mem driver, retrieve the CXL DVSEC
position and warn about the implications of not finding it. Allow for
mailbox operation even if the CXL DVSEC is missing.

Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
Changes since v3:
- Move the s/device_dvsec/cxl_dvsec/ rename one patch sooner (Jonathan)
- Warn, don't fail, when CXL DVSEC not found

 drivers/cxl/cxlmem.h |    2 ++
 drivers/cxl/pci.c    |    6 ++++++
 2 files changed, 8 insertions(+)

Comments

Jonathan Cameron Feb. 2, 2022, 9:36 a.m. UTC | #1
On Tue, 01 Feb 2022 14:06:32 -0800
Dan Williams <dan.j.williams@intel.com> wrote:

> From: Ben Widawsky <ben.widawsky@intel.com>
> 
> The PCIe device DVSEC, defined in the CXL 2.0 spec, 8.1.3 is required to
> be implemented by CXL 2.0 endpoint devices. In preparation for consuming
> this information in a new cxl_mem driver, retrieve the CXL DVSEC
> position and warn about the implications of not finding it. Allow for
> mailbox operation even if the CXL DVSEC is missing.
> 
> Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

> ---
> Changes since v3:
> - Move the s/device_dvsec/cxl_dvsec/ rename one patch sooner (Jonathan)
> - Warn, don't fail, when CXL DVSEC not found
> 
>  drivers/cxl/cxlmem.h |    2 ++
>  drivers/cxl/pci.c    |    6 ++++++
>  2 files changed, 8 insertions(+)
> 
> diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
> index 90d67fff5bed..5cf5329e13a9 100644
> --- a/drivers/cxl/cxlmem.h
> +++ b/drivers/cxl/cxlmem.h
> @@ -98,6 +98,7 @@ struct cxl_mbox_cmd {
>   *
>   * @dev: The device associated with this CXL state
>   * @regs: Parsed register blocks
> + * @cxl_dvsec: Offset to the PCIe device DVSEC
>   * @payload_size: Size of space for payload
>   *                (CXL 2.0 8.2.8.4.3 Mailbox Capabilities Register)
>   * @lsa_size: Size of Label Storage Area
> @@ -126,6 +127,7 @@ struct cxl_dev_state {
>  	struct device *dev;
>  
>  	struct cxl_regs regs;
> +	int cxl_dvsec;
>  
>  	size_t payload_size;
>  	size_t lsa_size;
> diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c
> index bf14c365ea33..c94002166084 100644
> --- a/drivers/cxl/pci.c
> +++ b/drivers/cxl/pci.c
> @@ -408,6 +408,12 @@ static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
>  	if (IS_ERR(cxlds))
>  		return PTR_ERR(cxlds);
>  
> +	cxlds->cxl_dvsec = pci_find_dvsec_capability(
> +		pdev, PCI_DVSEC_VENDOR_ID_CXL, CXL_DVSEC_PCIE_DEVICE);
> +	if (!cxlds->cxl_dvsec)
> +		dev_warn(&pdev->dev,
> +			 "Device DVSEC not present, skip CXL.mem init\n");
> +
>  	rc = cxl_setup_regs(pdev, CXL_REGLOC_RBI_MEMDEV, &map);
>  	if (rc)
>  		return rc;
>
diff mbox series

Patch

diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
index 90d67fff5bed..5cf5329e13a9 100644
--- a/drivers/cxl/cxlmem.h
+++ b/drivers/cxl/cxlmem.h
@@ -98,6 +98,7 @@  struct cxl_mbox_cmd {
  *
  * @dev: The device associated with this CXL state
  * @regs: Parsed register blocks
+ * @cxl_dvsec: Offset to the PCIe device DVSEC
  * @payload_size: Size of space for payload
  *                (CXL 2.0 8.2.8.4.3 Mailbox Capabilities Register)
  * @lsa_size: Size of Label Storage Area
@@ -126,6 +127,7 @@  struct cxl_dev_state {
 	struct device *dev;
 
 	struct cxl_regs regs;
+	int cxl_dvsec;
 
 	size_t payload_size;
 	size_t lsa_size;
diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c
index bf14c365ea33..c94002166084 100644
--- a/drivers/cxl/pci.c
+++ b/drivers/cxl/pci.c
@@ -408,6 +408,12 @@  static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	if (IS_ERR(cxlds))
 		return PTR_ERR(cxlds);
 
+	cxlds->cxl_dvsec = pci_find_dvsec_capability(
+		pdev, PCI_DVSEC_VENDOR_ID_CXL, CXL_DVSEC_PCIE_DEVICE);
+	if (!cxlds->cxl_dvsec)
+		dev_warn(&pdev->dev,
+			 "Device DVSEC not present, skip CXL.mem init\n");
+
 	rc = cxl_setup_regs(pdev, CXL_REGLOC_RBI_MEMDEV, &map);
 	if (rc)
 		return rc;