PCI: Support PCIe devices with short cfg_size

If a device quirk modifies the pci_dev->cfg_size to be less than
PCI_CFG_SPACE_EXP_SIZE (4096), but greater than PCI_CFG_SPACE_SIZE (256),
the PCI sysfs interface truncates the readable size to PCI_CFG_SPACE_SIZE.

Allow sysfs access to config space up to cfg_size, even if the device
doesn't support the entire 4096-byte PCIe config space.

Note that pci_read_config() and pci_write_config() limit access to
dev->cfg_size even though pcie_config_attr contains 4096 (the maximum
size).

Signed-off-by: Jason S. McMullan <jason.mcmullan@netronome.com>
[simon: edited changelog]
Signed-off-by: Simon Horman <simon.horman@netronome.com>
[bhelgaas: more changelog edits]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 92618686604cb9d314aa1e6bf833363cfbaaa1b5..9cd27b703dd683b73947d8844b67072b079f5c88 100644 (file)
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -1369,10 +1369,10 @@ int __must_check pci_create_sysfs_dev_files(struct pci_dev *pdev)
        if (!sysfs_initialized)
                return -EACCES;
 
-       if (pdev->cfg_size < PCI_CFG_SPACE_EXP_SIZE)
-               retval = sysfs_create_bin_file(&pdev->dev.kobj, &pci_config_attr);
-       else
+       if (pdev->cfg_size > PCI_CFG_SPACE_SIZE)
                retval = sysfs_create_bin_file(&pdev->dev.kobj, &pcie_config_attr);
+       else
+               retval = sysfs_create_bin_file(&pdev->dev.kobj, &pci_config_attr);
        if (retval)
                goto err;
 
@@ -1424,10 +1424,10 @@ err_rom_file:
 err_resource_files:
        pci_remove_resource_files(pdev);
 err_config_file:
-       if (pdev->cfg_size < PCI_CFG_SPACE_EXP_SIZE)
-               sysfs_remove_bin_file(&pdev->dev.kobj, &pci_config_attr);
-       else
+       if (pdev->cfg_size > PCI_CFG_SPACE_SIZE)
                sysfs_remove_bin_file(&pdev->dev.kobj, &pcie_config_attr);
+       else
+               sysfs_remove_bin_file(&pdev->dev.kobj, &pci_config_attr);
 err:
        return retval;
 }
@@ -1461,10 +1461,10 @@ void pci_remove_sysfs_dev_files(struct pci_dev *pdev)
 
        pci_remove_capabilities_sysfs(pdev);
 
-       if (pdev->cfg_size < PCI_CFG_SPACE_EXP_SIZE)
-               sysfs_remove_bin_file(&pdev->dev.kobj, &pci_config_attr);
-       else
+       if (pdev->cfg_size > PCI_CFG_SPACE_SIZE)
                sysfs_remove_bin_file(&pdev->dev.kobj, &pcie_config_attr);
+       else
+               sysfs_remove_bin_file(&pdev->dev.kobj, &pci_config_attr);
 
        pci_remove_resource_files(pdev);