target/linux/generic/backport-5.10/850-v5.17-0006-PCI-aardvark-Disable-bus-mastering-when-unbinding-dr.patch

   1 From a46f2f6dd4093438d9615dfbf5c0fea2a9835dba Mon Sep 17 00:00:00 2001
   2 From: =?UTF-8?q?Pali=20Roh=C3=A1r?= <pali@kernel.org>
   3 Date: Tue, 30 Nov 2021 18:29:08 +0100
   4 Subject: [PATCH] PCI: aardvark: Disable bus mastering when unbinding driver
   5 MIME-Version: 1.0
   6 Content-Type: text/plain; charset=UTF-8
   7 Content-Transfer-Encoding: 8bit
   8
   9 Ensure that after driver unbind PCIe cards are not able to forward
  10 memory and I/O requests in the upstream direction.
  11
  12 Link: https://lore.kernel.org/r/20211130172913.9727-7-kabel@kernel.org
  13 Signed-off-by: Pali Rohár <pali@kernel.org>
  14 Signed-off-by: Marek Behún <kabel@kernel.org>
  15 Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
  16 ---
  17  drivers/pci/controller/pci-aardvark.c | 6 ++++++
  18  1 file changed, 6 insertions(+)
  19
  20 --- a/drivers/pci/controller/pci-aardvark.c
  21 +++ b/drivers/pci/controller/pci-aardvark.c
  22 @@ -1690,6 +1690,7 @@ static int advk_pcie_remove(struct platf
  23  {
  24         struct advk_pcie *pcie = platform_get_drvdata(pdev);
  25         struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie);
  26 +       u32 val;
  27         int i;
  28
  29         /* Remove PCI bus with all devices */
  30 @@ -1698,6 +1699,11 @@ static int advk_pcie_remove(struct platf
  31         pci_remove_root_bus(bridge->bus);
  32         pci_unlock_rescan_remove();
  33
  34 +       /* Disable Root Bridge I/O space, memory space and bus mastering */
  35 +       val = advk_readl(pcie, PCIE_CORE_CMD_STATUS_REG);
  36 +       val &= ~(PCI_COMMAND_IO | PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER);
  37 +       advk_writel(pcie, val, PCIE_CORE_CMD_STATUS_REG);
  38 +
  39         /* Remove IRQ domains */
  40         advk_pcie_remove_msi_irq_domain(pcie);
  41         advk_pcie_remove_irq_domain(pcie);