diff mbox

[v10,06/10] PCI: Introduce generic domain handling for PCI busses.

Message ID 1410184472-17630-7-git-send-email-Liviu.Dudau@arm.com
State New
Headers show

Commit Message

Liviu Dudau Sept. 8, 2014, 1:54 p.m. UTC 
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 want 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 busses except the root bus will inherit the domain_nr
value from their parent.

Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Catalin Marinas <Catalin.Marinas@arm.com>
[Renamed pci_set_domain_nr() to pci_bus_assign_domain_nr()]
Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>
---
 drivers/pci/probe.c | 11 ++++++++---
 include/linux/pci.h | 21 +++++++++++++++++++++
 2 files changed, 29 insertions(+), 3 deletions(-)

Comments

Catalin Marinas Sept. 8, 2014, 2:03 p.m. UTC | #1 
On Mon, Sep 08, 2014 at 02:54:28PM +0100, Liviu Dudau wrote:
> 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 want 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 busses except the root bus will inherit the domain_nr
> value from their parent.
> 
> Cc: Bjorn Helgaas <bhelgaas@google.com>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Signed-off-by: Catalin Marinas <Catalin.Marinas@arm.com>
> [Renamed pci_set_domain_nr() to pci_bus_assign_domain_nr()]
> Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>

I'm probably the author here, but the patch log doesn't say so (I don't
mind, just a remark).
Liviu Dudau Sept. 8, 2014, 2:05 p.m. UTC | #2 
On Mon, Sep 08, 2014 at 03:03:21PM +0100, Catalin Marinas wrote:
> On Mon, Sep 08, 2014 at 02:54:28PM +0100, Liviu Dudau wrote:
> > 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 want 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 busses except the root bus will inherit the domain_nr
> > value from their parent.
> > 
> > Cc: Bjorn Helgaas <bhelgaas@google.com>
> > Cc: Arnd Bergmann <arnd@arndb.de>
> > Signed-off-by: Catalin Marinas <Catalin.Marinas@arm.com>
> > [Renamed pci_set_domain_nr() to pci_bus_assign_domain_nr()]
> > Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>
> 
> I'm probably the author here, but the patch log doesn't say so (I don't
> mind, just a remark).

I've took you patch initially from an email fragment, sorry, should've
altered the commiter accordingly.

Best regards,
Liviu

> 
> -- 
> Catalin
diff mbox

Patch

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 5ff72ec..ef891d2 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -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;
 }
 
@@ -672,7 +676,7 @@  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;
 
@@ -1768,13 +1772,14 @@  struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
 
 	bridge->dev.parent = parent;
 
-	b = pci_alloc_bus();
+	b = pci_alloc_bus(NULL);
 	if (!b)
 		goto err_out;
 
 	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 */
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 61978a4..a494e5d 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -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);