[PATCH 5.15 111/135] PCI: aardvark: Disable bus mastering when unbinding driver

Greg Kroah-Hartman
2022-05-10T14:09:56Z

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From: Pali Rohár <pali@kernel.org>

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>
---
drivers/pci/controller/pci-aardvark.c | 6 ++++++
1 file changed, 6 insertions(+)

--- a/drivers/pci/controller/pci-aardvark.c
+++ b/drivers/pci/controller/pci-aardvark.c
@@ -1679,6 +1679,7 @@ static int advk_pcie_remove(struct platf
{
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 platf
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);