Subject: Re: linux-next: manual merge of the tip tree with the pci tree

From: Stephen Rothwell <[email-masked]>
Date: Tue, 13 Oct 2020 14:31:57 +1100

Hi all,

On Fri, 25 Sep 2020 15:21:18 +1000 Stephen Rothwell <[email-masked]> wrote:
> 
> Today's linux-next merge of the tip tree got a conflict in:
> 
>   drivers/pci/controller/vmd.c
> 
> between commit:
> 
>   42443f036042 ("PCI: vmd: Create IRQ Domain configuration helper")
> 
> from the pci tree and commit:
> 
>   585dfe8abc44 ("PCI: vmd: Dont abuse vector irqomain as parent")
> 
> from the tip tree.
> 
> I fixed it up (see below) and can carry the fix as necessary. This
> is now fixed as far as linux-next is concerned, but any non trivial
> conflicts should be mentioned to your upstream maintainer when your tree
> is submitted for merging.  You may also want to consider cooperating
> with the maintainer of the conflicting tree to minimise any particularly
> complex conflicts.
> 
> diff --cc drivers/pci/controller/vmd.c
> index 3c4418cbde1c,aa1b12bac9a1..000000000000
> --- a/drivers/pci/controller/vmd.c
> +++ b/drivers/pci/controller/vmd.c
> @@@ -304,50 -298,6 +304,50 @@@ static struct msi_domain_info vmd_msi_d
>   	.chip		= &vmd_msi_controller,
>   };
>   
>  +static void vmd_enable_msi_remapping(struct vmd_dev *vmd, bool enable)
>  +{
>  +	u16 reg;
>  +
>  +	pci_read_config_word(vmd->dev, PCI_REG_VMCONFIG, &reg);
>  +	reg = enable ? (reg & ~0x2) : (reg | 0x2);
>  +	pci_write_config_word(vmd->dev, PCI_REG_VMCONFIG, reg);
>  +}
>  +
>  +static int vmd_create_irq_domain(struct vmd_dev *vmd)
>  +{
>  +	struct fwnode_handle *fn;
>  +
>  +	fn = irq_domain_alloc_named_id_fwnode("VMD-MSI", vmd->sysdata.domain);
>  +	if (!fn)
>  +		return -ENODEV;
>  +
>  +	vmd->irq_domain = pci_msi_create_irq_domain(fn, &vmd_msi_domain_info,
> - 						    x86_vector_domain);
> ++						    NULL);
>  +	if (!vmd->irq_domain) {
>  +		irq_domain_free_fwnode(fn);
>  +		return -ENODEV;
>  +	}
>  +
>  +	return 0;
>  +}
>  +
>  +static void vmd_remove_irq_domain(struct vmd_dev *vmd)
>  +{
>  +	/*
>  +	 * Some production BIOS won't enable remapping between soft reboots.
>  +	 * Ensure remapping is restored before unloading the driver
>  +	 */
>  +	if (!vmd->msix_count)
>  +		vmd_enable_msi_remapping(vmd, true);
>  +
>  +	if (vmd->irq_domain) {
>  +		struct fwnode_handle *fn = vmd->irq_domain->fwnode;
>  +
>  +		irq_domain_remove(vmd->irq_domain);
>  +		irq_domain_free_fwnode(fn);
>  +	}
>  +}
>  +
>   static char __iomem *vmd_cfg_addr(struct vmd_dev *vmd, struct pci_bus *bus,
>   				  unsigned int devfn, int reg, int len)
>   {
> @@@ -717,12 -568,24 +717,18 @@@ static int vmd_enable_domain(struct vmd
>   
>   	sd->node = pcibus_to_node(vmd->dev->bus);
>   
>  -	fn = irq_domain_alloc_named_id_fwnode("VMD-MSI", vmd->sysdata.domain);
>  -	if (!fn)
>  -		return -ENODEV;
>  -
>  -	vmd->irq_domain = pci_msi_create_irq_domain(fn, &vmd_msi_domain_info,
>  -						    NULL);
>  -
>  -	if (!vmd->irq_domain) {
>  -		irq_domain_free_fwnode(fn);
>  -		return -ENODEV;
>  +	if (vmd->msix_count) {
>  +		ret = vmd_create_irq_domain(vmd);
>  +		if (ret)
>  +			return ret;
>   	}
>   
> + 	/*
> + 	 * Override the irq domain bus token so the domain can be distinguished
> + 	 * from a regular PCI/MSI domain.
> + 	 */
> + 	irq_domain_update_bus_token(vmd->irq_domain, DOMAIN_BUS_VMD_MSI);
> + 
>   	pci_add_resource(&resources, &vmd->resources[0]);
>   	pci_add_resource_offset(&resources, &vmd->resources[1], offset[0]);
>   	pci_add_resource_offset(&resources, &vmd->resources[2], offset[1]);

This is now a conflict between the pci tree and Linus' tree.

-- 
Cheers,
Stephen Rothwell