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Commit 670ba0c8 authored by Catalin Marinas's avatar Catalin Marinas Committed by Bjorn Helgaas
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PCI: Add generic domain handling 



The handling of PCI domains (or PCI segments in ACPI speak) is usually a
straightforward affair but its implementation is currently left to the
architectural code, with pci_domain_nr(b) querying the value of the domain
associated with bus b.

This patch introduces CONFIG_PCI_DOMAINS_GENERIC as an option that can be
selected if an architecture wants a simple implementation where the value
of the domain associated with a bus is stored in struct pci_bus.

The architectures that select CONFIG_PCI_DOMAINS_GENERIC will then have to
implement pci_bus_assign_domain_nr() as a way of setting the domain number
associated with a root bus.  All child buses except the root bus will
inherit the domain_nr value from their parent.

Signed-off-by: default avatarCatalin Marinas <Catalin.Marinas@arm.com>
[Renamed pci_set_domain_nr() to pci_bus_assign_domain_nr()]
Signed-off-by: default avatarLiviu Dudau <Liviu.Dudau@arm.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
CC: Arnd Bergmann <arnd@arndb.de>
parent 0b0b0893

drivers/pci/probe.c

+8 −3
Original line number Diff line number Diff line
@@ -485,7 +485,7 @@ void pci_read_bridge_bases(struct pci_bus *child) 
	}

}



static struct pci_bus *pci_alloc_bus(void)

static struct pci_bus *pci_alloc_bus(struct pci_bus *parent)

{

	struct pci_bus *b;
@@ -500,6 +500,10 @@ static struct pci_bus *pci_alloc_bus(void) 
	INIT_LIST_HEAD(&b->resources);

	b->max_bus_speed = PCI_SPEED_UNKNOWN;

	b->cur_bus_speed = PCI_SPEED_UNKNOWN;

#ifdef CONFIG_PCI_DOMAINS_GENERIC

	if (parent)

		b->domain_nr = parent->domain_nr;

#endif

	return b;

}
@@ -671,7 +675,7 @@ static struct pci_bus *pci_alloc_child_bus(struct pci_bus *parent, 
	/*

	 * Allocate a new bus, and inherit stuff from the parent..

	 */

	child = pci_alloc_bus();

	child = pci_alloc_bus(parent);

	if (!child)

		return NULL;
@@ -1761,13 +1765,14 @@ struct pci_bus *pci_create_root_bus(struct device *parent, int bus, 
	char bus_addr[64];

	char *fmt;



	b = pci_alloc_bus();

	b = pci_alloc_bus(NULL);

	if (!b)

		return NULL;



	b->sysdata = sysdata;

	b->ops = ops;

	b->number = b->busn_res.start = bus;

	pci_bus_assign_domain_nr(b, parent);

	b2 = pci_find_bus(pci_domain_nr(b), bus);

	if (b2) {

		/* If we already got to this bus through a different bridge, ignore it */

include/linux/pci.h

+21 −0
Original line number Diff line number Diff line
@@ -456,6 +456,9 @@ struct pci_bus { 
	unsigned char	primary;	/* number of primary bridge */

	unsigned char	max_bus_speed;	/* enum pci_bus_speed */

	unsigned char	cur_bus_speed;	/* enum pci_bus_speed */

#ifdef CONFIG_PCI_DOMAINS_GENERIC

	int		domain_nr;

#endif



	char		name[48];
@@ -1288,6 +1291,24 @@ static inline int pci_domain_nr(struct pci_bus *bus) { return 0; } 
static inline int pci_proc_domain(struct pci_bus *bus) { return 0; }

#endif /* CONFIG_PCI_DOMAINS */



/*

 * Generic implementation for PCI domain support. If your

 * architecture does not need custom management of PCI

 * domains then this implementation will be used

 */

#ifdef CONFIG_PCI_DOMAINS_GENERIC

static inline int pci_domain_nr(struct pci_bus *bus)

{

	return bus->domain_nr;

}

void pci_bus_assign_domain_nr(struct pci_bus *bus, struct device *parent);

#else

static inline void pci_bus_assign_domain_nr(struct pci_bus *bus,

					struct device *parent)

{

}

#endif



/* some architectures require additional setup to direct VGA traffic */

typedef int (*arch_set_vga_state_t)(struct pci_dev *pdev, bool decode,

		      unsigned int command_bits, u32 flags);