Commit 36bfc6ad authored by Dan Williams's avatar Dan Williams
Browse files

cxl/pci: Make cxl_dvsec_ranges() failure not fatal to cxl_pci 



cxl_dvsec_ranges(), the helper for enumerating the presence of an active
legacy CXL.mem configuration on a CXL 2.0 Memory Expander, is not fatal
for cxl_pci because there is still value to enable mailbox operations
even if CXL.mem operation is disabled. Recall that the reason cxl_pci
does this initialization and not cxl_mem is to preserve the useful
property (for unit testing) that cxl_mem is cxl_memdev + mmio generic,
and does not require access to a 'struct pci_dev' to issue config
cycles.

Update 'struct cxl_endpoint_dvsec_info' to carry either a positive
number of non-zero size legacy CXL DVSEC ranges, or the negative error
code from __cxl_dvsec_ranges() in its @ranges member.

Reported-by: default avatarKrzysztof Zach <krzysztof.zach@intel.com>
Fixes: 560f7855 ("cxl/pci: Retrieve CXL DVSEC memory info")
Reviewed-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: default avatarDavidlohr Bueso <dave@stgolabs.net>
Link: https://lore.kernel.org/r/164730735869.3806189.4032428192652531946.stgit@dwillia2-desk3.amr.corp.intel.com


Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent fbaf2b07

drivers/cxl/pci.c

+18 −9
Original line number Diff line number Diff line
@@ -463,13 +463,18 @@ static int wait_for_media_ready(struct cxl_dev_state *cxlds) 
	return 0;

}



static int cxl_dvsec_ranges(struct cxl_dev_state *cxlds)

/*

 * Return positive number of non-zero ranges on success and a negative

 * error code on failure. The cxl_mem driver depends on ranges == 0 to

 * init HDM operation.

 */

static int __cxl_dvsec_ranges(struct cxl_dev_state *cxlds,

			      struct cxl_endpoint_dvsec_info *info)

{

	struct cxl_endpoint_dvsec_info *info = &cxlds->info;

	struct pci_dev *pdev = to_pci_dev(cxlds->dev);

	int hdm_count, rc, i, ranges = 0;

	struct device *dev = &pdev->dev;

	int d = cxlds->cxl_dvsec;

	int hdm_count, rc, i;

	u16 cap, ctrl;



	if (!d) {
@@ -546,10 +551,17 @@ static int cxl_dvsec_ranges(struct cxl_dev_state *cxlds) 
		};



		if (size)

			info->ranges++;

			ranges++;

	}



	return 0;

	return ranges;

}



static void cxl_dvsec_ranges(struct cxl_dev_state *cxlds)

{

	struct cxl_endpoint_dvsec_info *info = &cxlds->info;



	info->ranges = __cxl_dvsec_ranges(cxlds, info);

}



static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
@@ -618,10 +630,7 @@ static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) 
	if (rc)

		return rc;



	rc = cxl_dvsec_ranges(cxlds);

	if (rc)

		dev_warn(&pdev->dev,

			 "Failed to get DVSEC range information (%d)\n", rc);

	cxl_dvsec_ranges(cxlds);



	cxlmd = devm_cxl_add_memdev(cxlds);

	if (IS_ERR(cxlmd))