Re: [PATCH 5/7] PCI: aardvark: Disable bus mastering and mask all interrupts when unbinding driver

[Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>]

On Sun, Oct 31, 2021 at 07:12:31PM +0100, Marek Behún wrote:
> From: Pali Rohár <pali@kernel.org>
> 
> Ensure that after driver unbinding PCIe cards are not be able to forward
> memory and I/O requests in the upstream direction and that no interrupt can
> be triggered.

Two actions - likely to require two patches.

> Fixes: 526a76991b7b ("PCI: aardvark: Implement driver 'remove' function and allow to build it as module")
> Signed-off-by: Pali Rohár <pali@kernel.org>
> Signed-off-by: Marek Behún <kabel@kernel.org>
> Cc: stable@vger.kernel.org

You keep adding stable tags, I suppose because you have fixes on top
that will need to go to stable, as said multiple times please let's
not jump the gun, let's fix (if this is fixing anything) mainline
first.

Lorenzo

>  drivers/pci/controller/pci-aardvark.c | 29 +++++++++++++++++++++++++++
>  1 file changed, 29 insertions(+)
> 
> diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c
> index 71ce9f02d596..08b34accfe2f 100644
> --- a/drivers/pci/controller/pci-aardvark.c
> +++ b/drivers/pci/controller/pci-aardvark.c
> @@ -1695,13 +1695,42 @@ 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 */
>  	pci_lock_rescan_remove();
>  	pci_stop_root_bus(bridge->bus);
>  	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);
> +
> +	/* Disable MSI */
> +	val = advk_readl(pcie, PCIE_CORE_CTRL2_REG);
> +	val &= ~PCIE_CORE_CTRL2_MSI_ENABLE;
> +	advk_writel(pcie, val, PCIE_CORE_CTRL2_REG);
> +
> +	/* Clear MSI address */
> +	advk_writel(pcie, 0, PCIE_MSI_ADDR_LOW_REG);
> +	advk_writel(pcie, 0, PCIE_MSI_ADDR_HIGH_REG);
> +
> +	/* Mask all interrupts */
> +	advk_writel(pcie, PCIE_MSI_ALL_MASK, PCIE_MSI_MASK_REG);
> +	advk_writel(pcie, PCIE_ISR0_ALL_MASK, PCIE_ISR0_MASK_REG);
> +	advk_writel(pcie, PCIE_ISR1_ALL_MASK, PCIE_ISR1_MASK_REG);
> +	advk_writel(pcie, PCIE_IRQ_ALL_MASK, HOST_CTRL_INT_MASK_REG);
> +
> +	/* Clear all interrupts */
> +	advk_writel(pcie, PCIE_MSI_ALL_MASK, PCIE_MSI_STATUS_REG);
> +	advk_writel(pcie, PCIE_ISR0_ALL_MASK, PCIE_ISR0_REG);
> +	advk_writel(pcie, PCIE_ISR1_ALL_MASK, PCIE_ISR1_REG);
> +	advk_writel(pcie, PCIE_IRQ_ALL_MASK, HOST_CTRL_INT_STATUS_REG);
> +
> +	/* Remove IRQ domains */
>  	advk_pcie_remove_msi_irq_domain(pcie);
>  	advk_pcie_remove_irq_domain(pcie);
>  
> -- 
> 2.32.0
>