cxl/pci: Unconditionally unmask 256B Flit errors

The current check for 256B Flit mode is incomplete and unnecessary. It
is incomplete because it fails to consider the link speed, or check for
CXL link capabilities. It is unnecessary because unconditionally
unmasking 256B Flit errors is a nop when 256B Flit operation is not
available.

Remove this check in preparation for creating a cxl_probe_link() helper
to centralize this detection.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/168679263124.3436160.6228910132469454346.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Author: djbw

drivers/cxl/pci.c

@@ -368,19 +368,6 @@ static bool is_cxl_restricted(struct pci_dev *pdev)
 	return pci_pcie_type(pdev) == PCI_EXP_TYPE_RC_END;
 }
 
-/*
- * CXL v3.0 6.2.3 Table 6-4
- * The table indicates that if PCIe Flit Mode is set, then CXL is in 256B flits
- * mode, otherwise it's 68B flits mode.
- */
-static bool cxl_pci_flit_256(struct pci_dev *pdev)
-{
-	u16 lnksta2;
-
-	pcie_capability_read_word(pdev, PCI_EXP_LNKSTA2, &lnksta2);
-	return lnksta2 & PCI_EXP_LNKSTA2_FLIT;
-}
-
 static int cxl_pci_ras_unmask(struct pci_dev *pdev)
 {
 	struct pci_host_bridge *host_bridge = pci_find_host_bridge(pdev->bus);
@@ -407,9 +394,8 @@ static int cxl_pci_ras_unmask(struct pci_dev *pdev)
 		addr = cxlds->regs.ras + CXL_RAS_UNCORRECTABLE_MASK_OFFSET;
 		orig_val = readl(addr);
 
-		mask = CXL_RAS_UNCORRECTABLE_MASK_MASK;
-		if (!cxl_pci_flit_256(pdev))
-			mask &= ~CXL_RAS_UNCORRECTABLE_MASK_F256B_MASK;
+		mask = CXL_RAS_UNCORRECTABLE_MASK_MASK |
+		       CXL_RAS_UNCORRECTABLE_MASK_F256B_MASK;
 		val = orig_val & ~mask;
 		writel(val, addr);
 		dev_dbg(&pdev->dev,