PCI: Allow root and child buses to have different pci_ops (07e29295) · Commits · 戴 / test

PCI host bridges often have different ways to access the root and child bus config spaces. The host bridge drivers have invented their own abstractions to handle this. Let's support having different root and child bus pci_ops so these per driver abstractions can be removed. Link: https://lore.kernel.org/r/20200821035420.380495-2-robh@kernel.org Signed-off-by:

Rob Herring <robh@kernel.org> Signed-off-by:

Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/probe.c

+7 −1

Original line number	Diff line number	Diff line
		@@ -1036,6 +1036,7 @@ static struct pci_bus pci_alloc_child_bus(struct pci_bus parent,
		struct pci_dev *bridge, int busnr)
		{
		struct pci_bus *child;
		struct pci_host_bridge *host;
		int i;
		int ret;

		@@ -1045,11 +1046,16 @@ static struct pci_bus pci_alloc_child_bus(struct pci_bus parent,
		return NULL;

		child->parent = parent;
		child->ops = parent->ops;
		child->msi = parent->msi;
		child->sysdata = parent->sysdata;
		child->bus_flags = parent->bus_flags;

		host = pci_find_host_bridge(parent);
		if (host->child_ops)
		child->ops = host->child_ops;
		else
		child->ops = parent->ops;

		/*
		* Initialize some portions of the bus device, but don't register
		* it now as the parent is not properly set up yet.

include/linux/pci.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -523,6 +523,7 @@ struct pci_host_bridge {
		struct device dev;
		struct pci_bus bus; / Root bus */
		struct pci_ops *ops;
		struct pci_ops *child_ops;
		void *sysdata;
		int busnr;
		struct list_head windows; /* resource_entry */

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