PCI: rockchip: Add remove() support

Currently, if we try to unbind the platform device, the remove will
succeed, but the removal won't undo most of the registration, leaving
partially-configured PCI devices in the system.

This allows, for example, a simple 'lspci' to crash the system, as it will
try to touch the freed (via devm_*) driver structures, e.g., on RK3399:

  # echo f8000000.pcie > /sys/bus/platform/drivers/rockchip-pcie/unbind
  # lspci

So let's implement device remove().

Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Shawn Lin <shawn.lin@rock-chips.com>

1 files changed, 34 insertions, 2 deletions

diff --git a/drivers/pci/host/pcie-rockchip.c b/drivers/pci/host/pcie-rockchip.c
index 94feb7dfd8f4..76f2edc93663 100644
--- a/drivers/pci/host/pcie-rockchip.c
+++ b/drivers/pci/host/pcie-rockchip.c
@@ -223,9 +223,11 @@ struct rockchip_pcie {
         int     link_gen;
         struct  device *dev;
         struct  irq_domain *irq_domain;
-        u32     io_size;
         int     offset;
+        struct pci_bus *root_bus;
+        struct resource *io;
         phys_addr_t io_bus_addr;
+        u32     io_size;
         void    __iomem *msg_region;
         u32     mem_size;
         phys_addr_t msg_bus_addr;
@@ -1366,6 +1368,7 @@ static int rockchip_pcie_probe(struct platform_device *pdev)
                                          err, io);
                                 continue;
                         }
+                        rockchip->io = io;
                         break;
                 case IORESOURCE_MEM:
                         mem = win->res;
@@ -1397,6 +1400,7 @@ static int rockchip_pcie_probe(struct platform_device *pdev)
                 err = -ENOMEM;
                 goto err_free_res;
         }
+        rockchip->root_bus = bus;
 
         pci_bus_size_bridges(bus);
         pci_bus_assign_resources(bus);
@@ -1427,6 +1431,34 @@ err_aclk_pcie:
         return err;
 }
 
+static int rockchip_pcie_remove(struct platform_device *pdev)
+{
+        struct device *dev = &pdev->dev;
+        struct rockchip_pcie *rockchip = dev_get_drvdata(dev);
+
+        pci_stop_root_bus(rockchip->root_bus);
+        pci_remove_root_bus(rockchip->root_bus);
+        pci_unmap_iospace(rockchip->io);
+        irq_domain_remove(rockchip->irq_domain);
+
+        phy_power_off(rockchip->phy);
+        phy_exit(rockchip->phy);
+
+        clk_disable_unprepare(rockchip->clk_pcie_pm);
+        clk_disable_unprepare(rockchip->hclk_pcie);
+        clk_disable_unprepare(rockchip->aclk_perf_pcie);
+        clk_disable_unprepare(rockchip->aclk_pcie);
+
+        if (!IS_ERR(rockchip->vpcie3v3))
+                regulator_disable(rockchip->vpcie3v3);
+        if (!IS_ERR(rockchip->vpcie1v8))
+                regulator_disable(rockchip->vpcie1v8);
+        if (!IS_ERR(rockchip->vpcie0v9))
+                regulator_disable(rockchip->vpcie0v9);
+
+        return 0;
+}
+
 static const struct dev_pm_ops rockchip_pcie_pm_ops = {
         SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(rockchip_pcie_suspend_noirq,
                                       rockchip_pcie_resume_noirq)
@@ -1444,6 +1476,6 @@ static struct platform_driver rockchip_pcie_driver = {
                 .pm = &rockchip_pcie_pm_ops,
         },
         .probe = rockchip_pcie_probe,
-
+        .remove = rockchip_pcie_remove,
 };
 builtin_platform_driver(rockchip_pcie_driver);