Re: [PATCH V2 7/9] PCI: tegra: Add loadable kernel module support

[Manikanta Maddireddy <mmaddireddy@nvidia.com>]

On 29-Nov-17 5:31 PM, Mikko Perttunen wrote:
> On 25.11.2017 21:32, Manikanta Maddireddy wrote:
>> Implement remove callback function for Tegra PCIe driver to add
>> loadable kernel module support. Change PCI_TEGRA config to tristate to
>> allow pci-tegra driver to be build as a module.
>>
>> Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
>> ---
>> V2:
>> * no change in this patch
>>
>>  drivers/pci/host/Kconfig     |  2 +-
>>  drivers/pci/host/pci-tegra.c | 31 ++++++++++++++++++++++++++++++-
>>  2 files changed, 31 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
>> index 38d12980db0f..6fd2a5937804 100644
>> --- a/drivers/pci/host/Kconfig
>> +++ b/drivers/pci/host/Kconfig
>> @@ -34,7 +34,7 @@ config PCI_FTPCI100
>>      default ARCH_GEMINI
>>
>>  config PCI_TEGRA
>> -    bool "NVIDIA Tegra PCIe controller"
>> +    tristate "NVIDIA Tegra PCIe controller"
>>      depends on ARCH_TEGRA
>>      help
>>        Say Y here if you want support for the PCIe host controller found
>> diff --git a/drivers/pci/host/pci-tegra.c b/drivers/pci/host/pci-tegra.c
>> index 7f7b8c9c1e84..bbc2807bcd4a 100644
>> --- a/drivers/pci/host/pci-tegra.c
>> +++ b/drivers/pci/host/pci-tegra.c
>> @@ -35,6 +35,7 @@
>>  #include <linux/irqdomain.h>
>>  #include <linux/kernel.h>
>>  #include <linux/init.h>
>> +#include <linux/module.h>
>>  #include <linux/msi.h>
>>  #include <linux/of_address.h>
>>  #include <linux/of_pci.h>
>> @@ -2720,6 +2721,12 @@ static int tegra_pcie_debugfs_init(struct tegra_pcie *pcie)
>>      return -ENOMEM;
>>  }
>>
>> +static void tegra_pcie_debugfs_exit(struct tegra_pcie *pcie)
>> +{
>> +    debugfs_remove_recursive(pcie->debugfs);
>> +    pcie->debugfs = NULL;
>> +}
>> +
> 
> I think it's unnecessary to have a helper function for this - just inline it in the remove function.
This helper function can be used in tegra_pcie_debugfs_init(), I will publish a new patch calling this
helper function in both tegra_pcie_debugfs_exit and remove.
> 
>>  static int tegra_pcie_probe(struct platform_device *pdev)
>>  {
>>      struct device *dev = &pdev->dev;
>> @@ -2734,6 +2741,7 @@ static int tegra_pcie_probe(struct platform_device *pdev)
>>          return -ENOMEM;
>>
>>      pcie = pci_host_bridge_priv(host);
>> +    platform_set_drvdata(pdev, pcie);
>>
>>      pcie->soc = of_device_get_match_data(dev);
>>      INIT_LIST_HEAD(&pcie->buses);
>> @@ -2816,6 +2824,25 @@ static int tegra_pcie_probe(struct platform_device *pdev)
>>      return err;
>>  }
>>
>> +static int tegra_pcie_remove(struct platform_device *pdev)
>> +{
>> +    struct tegra_pcie *pcie = platform_get_drvdata(pdev);
>> +    struct pci_host_bridge *host = pci_host_bridge_from_priv(pcie);
>> +
>> +    if (IS_ENABLED(CONFIG_DEBUG_FS))
>> +        tegra_pcie_debugfs_exit(pcie);
>> +    pci_stop_root_bus(host->bus);
>> +    pci_remove_root_bus(host->bus);
>> +    if (IS_ENABLED(CONFIG_PCI_MSI))
>> +        tegra_pcie_disable_msi(pcie);
>> +    tegra_pcie_disable_ports(pcie);
>> +    tegra_pcie_free_resources(pcie);
>> +    tegra_pcie_disable_controller(pcie);
>> +    tegra_pcie_put_resources(pcie);
>> +
>> +    return 0;
>> +}
>> +
>>  static struct platform_driver tegra_pcie_driver = {
>>      .driver = {
>>          .name = "tegra-pcie",
>> @@ -2823,5 +2850,7 @@ static struct platform_driver tegra_pcie_driver = {
>>          .suppress_bind_attrs = true,
>>      },
>>      .probe = tegra_pcie_probe,
>> +    .remove = tegra_pcie_remove,
>>  };
>> -builtin_platform_driver(tegra_pcie_driver);
>> +module_platform_driver(tegra_pcie_driver);
>> +MODULE_LICENSE("GPL");
>>