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

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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: Krzysztof Zach <krzysztof.zach@intel.com>
Fixes: 560f785590 ("cxl/pci: Retrieve CXL DVSEC memory info")
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Link: https://lore.kernel.org/r/164730735869.3806189.4032428192652531946.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
This commit is contained in:
Dan Williams 2022-03-14 18:22:38 -07:00
parent fbaf2b079d
commit 36bfc6ad50
1 changed files with 18 additions and 9 deletions
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27
drivers/cxl/pci.c
View file

@ -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))