cxl/pci: Simplify CDAT retrieval error path

The cdat.table and cdat.length fields in struct cxl_port are set before
CDAT retrieval and must therefore be unset on failure.

Simplify by setting only on success.

Suggested-by: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
Link: https://lore.kernel.org/linux-cxl/20230209113422.00007017@Huawei.com/
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
[lukas: rebase and rephrase commit message]
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/r/7a5c7104fb6a3016dbaec1c5d0ed34619ea11a0c.1678543498.git.lukas@wunner.de
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c
index c868f4a..0609bd6 100644 (file)
--- a/drivers/cxl/core/pci.c
+++ b/drivers/cxl/core/pci.c
@@ -475,10 +475,10 @@ static int cxl_cdat_get_length(struct device *dev,
 
 static int cxl_cdat_read_table(struct device *dev,
                               struct pci_doe_mb *cdat_doe,
-                              struct cxl_cdat *cdat)
+                              void *cdat_table, size_t *cdat_length)
 {
-       size_t length = cdat->length;
-       __le32 *data = cdat->table;
+       size_t length = *cdat_length;
+       __le32 *data = cdat_table;
        int entry_handle = 0;
 
        do {
@@ -522,7 +522,7 @@ static int cxl_cdat_read_table(struct device *dev,
        } while (entry_handle != CXL_DOE_TABLE_ACCESS_LAST_ENTRY);
 
        /* Length in CDAT header may exceed concatenation of CDAT entries */
-       cdat->length -= length;
+       *cdat_length -= length;
 
        return 0;
 }
@@ -542,6 +542,7 @@ void read_cdat_data(struct cxl_port *port)
        struct cxl_dev_state *cxlds = cxlmd->cxlds;
        struct pci_dev *pdev = to_pci_dev(cxlds->dev);
        size_t cdat_length;
+       void *cdat_table;
        int rc;
 
        cdat_doe = pci_find_doe_mailbox(pdev, PCI_DVSEC_VENDOR_ID_CXL,
@@ -558,19 +559,19 @@ void read_cdat_data(struct cxl_port *port)
                return;
        }
 
-       port->cdat.table = devm_kzalloc(dev, cdat_length, GFP_KERNEL);
-       if (!port->cdat.table)
+       cdat_table = devm_kzalloc(dev, cdat_length, GFP_KERNEL);
+       if (!cdat_table)
                return;
 
-       port->cdat.length = cdat_length;
-       rc = cxl_cdat_read_table(dev, cdat_doe, &port->cdat);
+       rc = cxl_cdat_read_table(dev, cdat_doe, cdat_table, &cdat_length);
        if (rc) {
                /* Don't leave table data allocated on error */
-               devm_kfree(dev, port->cdat.table);
-               port->cdat.table = NULL;
-               port->cdat.length = 0;
+               devm_kfree(dev, cdat_table);
                dev_err(dev, "CDAT data read error\n");
        }
+
+       port->cdat.table = cdat_table;
+       port->cdat.length = cdat_length;
 }
 EXPORT_SYMBOL_NS_GPL(read_cdat_data, CXL);