PCI: aardvark: Disable bus mastering when unbinding driver

BugLink: https://bugs.launchpad.net/bugs/1978240
commit a46f2f6dd4093438d9615dfbf5c0fea2a9835dba upstream.

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>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c
index 7432eeafc8fe4cf929116df78e13109619a9738d..ee6ffba2af220f1e1c619f9ebd333575326ac11a 100644 (file)
--- a/drivers/pci/controller/pci-aardvark.c
+++ b/drivers/pci/controller/pci-aardvark.c
@@ -1679,6 +1679,7 @@ 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 */
@@ -1687,6 +1688,11 @@ 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);