PCI: aardvark: Disable bus mastering when unbinding driver

Ensure that after driver unbind PCIe cards are not able to forward
memory and I/O requests in the upstream direction.

Link: https://lore.kernel.org/r/20211130172913.9727-7-kabel@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c
index 6348584..12eae05 100644 (file)
--- a/drivers/pci/controller/pci-aardvark.c
+++ b/drivers/pci/controller/pci-aardvark.c
@@ -1695,6 +1695,7 @@ static int advk_pcie_remove(struct platform_device *pdev)
 {
        struct advk_pcie *pcie = platform_get_drvdata(pdev);
        struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie);
+       u32 val;
        int i;
 
        /* Remove PCI bus with all devices */
@@ -1703,6 +1704,11 @@ static int advk_pcie_remove(struct platform_device *pdev)
        pci_remove_root_bus(bridge->bus);
        pci_unlock_rescan_remove();
 
+       /* Disable Root Bridge I/O space, memory space and bus mastering */
+       val = advk_readl(pcie, PCIE_CORE_CMD_STATUS_REG);
+       val &= ~(PCI_COMMAND_IO | PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER);
+       advk_writel(pcie, val, PCIE_CORE_CMD_STATUS_REG);
+
        /* Remove IRQ domains */
        advk_pcie_remove_msi_irq_domain(pcie);
        advk_pcie_remove_irq_domain(pcie);