Now that the dust has settled and the prep work is upstream, adding PCI
domain support to x86 is a lot more straightforward.
Targetted for 2.6.24.
commit c7b14cf6aa39e09aef89a0cd08c553dba1ee7e98
Author: Jeff Garzik <[email protected]>
Date: Sat Sep 1 07:36:25 2007 -0400
PCI domain support for x86[-64]
aka "PCI segment" support, in ACPI lingo.
Signed-off-by: Jeff Garzik <[email protected]>
arch/i386/pci/acpi.c | 15 ++++++++++-----
arch/i386/pci/common.c | 6 ++++--
arch/x86_64/Kconfig | 4 ++++
include/asm-i386/pci.h | 14 ++++++++++++++
include/asm-x86_64/pci.h | 14 ++++++++++++++
5 files changed, 46 insertions(+), 7 deletions(-)
c7b14cf6aa39e09aef89a0cd08c553dba1ee7e98
diff --git a/arch/i386/pci/acpi.c b/arch/i386/pci/acpi.c
index bc8a44b..6beb789 100644
--- a/arch/i386/pci/acpi.c
+++ b/arch/i386/pci/acpi.c
@@ -11,6 +11,13 @@ struct pci_bus * __devinit pci_acpi_scan_root(struct acpi_device *device, int do
struct pci_sysdata *sd;
int pxm;
+#ifndef CONFIG_PCI_DOMAINS
+ if (domain != 0) {
+ printk(KERN_WARNING "PCI: Multiple domains not supported\n");
+ return NULL;
+ }
+#endif
+
/* Allocate per-root-bus (not per bus) arch-specific data.
* TODO: leak; this memory is never freed.
* It's arguable whether it's worth the trouble to care.
@@ -21,11 +28,9 @@ struct pci_bus * __devinit pci_acpi_scan_root(struct acpi_device *device, int do
return NULL;
}
- if (domain != 0) {
- printk(KERN_WARNING "PCI: Multiple domains not supported\n");
- kfree(sd);
- return NULL;
- }
+#ifdef CONFIG_PCI_DOMAINS
+ sd->domain = domain;
+#endif
sd->node = -1;
diff --git a/arch/i386/pci/common.c b/arch/i386/pci/common.c
index ebc6f3c..6d7a274 100644
--- a/arch/i386/pci/common.c
+++ b/arch/i386/pci/common.c
@@ -29,12 +29,14 @@ struct pci_raw_ops *raw_pci_ops;
static int pci_read(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 *value)
{
- return raw_pci_ops->read(0, bus->number, devfn, where, size, value);
+ return raw_pci_ops->read(pci_domain_nr(bus), bus->number,
+ devfn, where, size, value);
}
static int pci_write(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 value)
{
- return raw_pci_ops->write(0, bus->number, devfn, where, size, value);
+ return raw_pci_ops->write(pci_domain_nr(bus), bus->number,
+ devfn, where, size, value);
}
struct pci_ops pci_root_ops = {
diff --git a/arch/x86_64/Kconfig b/arch/x86_64/Kconfig
index ffa0364..1cb16c6 100644
--- a/arch/x86_64/Kconfig
+++ b/arch/x86_64/Kconfig
@@ -732,6 +732,10 @@ config PCI_MMCONFIG
bool "Support mmconfig PCI config space access"
depends on PCI && ACPI
+config PCI_DOMAINS
+ bool "PCI domain support"
+ depends on PCI
+
source "drivers/pci/pcie/Kconfig"
source "drivers/pci/Kconfig"
diff --git a/include/asm-i386/pci.h b/include/asm-i386/pci.h
index 4fcacc7..37d3322 100644
--- a/include/asm-i386/pci.h
+++ b/include/asm-i386/pci.h
@@ -5,12 +5,26 @@
#ifdef __KERNEL__
struct pci_sysdata {
+ int domain; /* PCI domain */
int node; /* NUMA node */
};
/* scan a bus after allocating a pci_sysdata for it */
extern struct pci_bus *pci_scan_bus_with_sysdata(int busno);
+#ifdef CONFIG_PCI_DOMAINS
+static inline int pci_domain_nr(struct pci_bus *bus)
+{
+ struct pci_sysdata *sd = bus->sysdata;
+ return sd->domain;
+}
+
+static inline int pci_proc_domain(struct pci_bus *bus)
+{
+ return pci_domain_nr(bus);
+}
+#endif /* CONFIG_PCI_DOMAINS */
+
#include <linux/mm.h> /* for struct page */
/* Can be used to override the logic in pci_scan_bus for skipping
diff --git a/include/asm-x86_64/pci.h b/include/asm-x86_64/pci.h
index 5da8cb0..6ce2731 100644
--- a/include/asm-x86_64/pci.h
+++ b/include/asm-x86_64/pci.h
@@ -6,12 +6,26 @@
#ifdef __KERNEL__
struct pci_sysdata {
+ int domain; /* PCI domain */
int node; /* NUMA node */
void* iommu; /* IOMMU private data */
};
extern struct pci_bus *pci_scan_bus_with_sysdata(int busno);
+#ifdef CONFIG_PCI_DOMAINS
+static inline int pci_domain_nr(struct pci_bus *bus)
+{
+ struct pci_sysdata *sd = bus->sysdata;
+ return sd->domain;
+}
+
+static inline int pci_proc_domain(struct pci_bus *bus)
+{
+ return pci_domain_nr(bus);
+}
+#endif /* CONFIG_PCI_DOMAINS */
+
#ifdef CONFIG_CALGARY_IOMMU
static inline void* pci_iommu(struct pci_bus *bus)
{
>
> +config PCI_DOMAINS
> + bool "PCI domain support"
> + depends on PCI
I don't think this should be a config option.
But there should be a pci=... option with Documentation to turn it off at runtime
> +static inline int pci_proc_domain(struct pci_bus *bus)
> +{
> + return pci_domain_nr(bus);
> +}
The second function is redundant?
-Andi
Andi Kleen wrote:
>>
>> +config PCI_DOMAINS
>> + bool "PCI domain support"
>> + depends on PCI
>
> I don't think this should be a config option.
CONFIG_PCI_DOMAINS is referenced in arch-neutral code, so the symbol
_must_ be defined.
It can be hidden, perhaps, if that makes our x86 maintainer happy :)
> But there should be a pci=... option with Documentation to turn it off at runtime
OK
>> +static inline int pci_proc_domain(struct pci_bus *bus)
>> +{
>> + return pci_domain_nr(bus);
>> +}
>
> The second function is redundant?
No, it's a hook we must implement, when CONFIG_PCI_DOMAINS is enabled.
Jeff
> > The second function is redundant?
>
> No, it's a hook we must implement, when CONFIG_PCI_DOMAINS is enabled.
Then the other function is redundant.
-Andi
Andi Kleen wrote:
>>> The second function is redundant?
>> No, it's a hook we must implement, when CONFIG_PCI_DOMAINS is enabled.
>
> Then the other function is redundant.
No, both functions are required by the interface.
Jeff
On Sat, Sep 01, 2007 at 10:32:23AM -0400, Jeff Garzik wrote:
>
> Now that the dust has settled and the prep work is upstream, adding
> PCI edomain support to x86 is a lot more straightforward.
>
> Targetted for 2.6.24.
Looks good to me.
Cheers,
Muli
On Sat, 01 Sep 2007 18:40:27 -0400 Jeff Garzik wrote:
> Andi Kleen wrote:
> >>> The second function is redundant?
> >> No, it's a hook we must implement, when CONFIG_PCI_DOMAINS is enabled.
> >
> > Then the other function is redundant.
>
> No, both functions are required by the interface.
by what interface? and why, please? (instead of just stating "required")
---
~Randy
*** Remember to use Documentation/SubmitChecklist when testing your code ***
Randy Dunlap wrote:
> On Sat, 01 Sep 2007 18:40:27 -0400 Jeff Garzik wrote:
>
>> Andi Kleen wrote:
>>>>> The second function is redundant?
>>>> No, it's a hook we must implement, when CONFIG_PCI_DOMAINS is enabled.
>>> Then the other function is redundant.
>> No, both functions are required by the interface.
>
> by what interface? and why, please? (instead of just stating "required")
grep for CONFIG_PCI_DOMAINS in arch code and include/linux/pci.h.
This is normal "arch" interface: you enable a define, and a group of
functions is assumed to be present. Otherwise (!defined), a set of stub
no-ops is activated for your arch.
I have implemented the [small] group of functions the code assumes to be
present, when CONFIG_PCI_DOMAINS is enabled, like all the other arches
that implement PCI domain support.
Jeff
Jeff Garzik wrote:
> Randy Dunlap wrote:
>> On Sat, 01 Sep 2007 18:40:27 -0400 Jeff Garzik wrote:
>>
>>> Andi Kleen wrote:
>>>>>> The second function is redundant?
>>>>> No, it's a hook we must implement, when CONFIG_PCI_DOMAINS is enabled.
>>>> Then the other function is redundant.
>>> No, both functions are required by the interface.
>>
>> by what interface? and why, please? (instead of just stating
>> "required")
>
> grep for CONFIG_PCI_DOMAINS in arch code and include/linux/pci.h.
Thanks, I get it.
> This is normal "arch" interface: you enable a define, and a group of
> functions is assumed to be present. Otherwise (!defined), a set of stub
> no-ops is activated for your arch.
>
> I have implemented the [small] group of functions the code assumes to be
> present, when CONFIG_PCI_DOMAINS is enabled, like all the other arches
> that implement PCI domain support.
+#ifdef CONFIG_PCI_DOMAINS
+static inline int pci_domain_nr(struct pci_bus *bus)
+{
+ struct pci_sysdata *sd = bus->sysdata;
+ return sd->domain;
+}
+
+static inline int pci_proc_domain(struct pci_bus *bus)
+{
+ return pci_domain_nr(bus);
+}
+#endif /* CONFIG_PCI_DOMAINS */
So if CONFIG_PCI_DOMAINS=y, proc_proc_domain() decides to print the domain nr
in /proc iff the domain nr != 0 ? so that the /proc file format is
different depending on the domain nr (0 vs. !0) ?
I suppose that is similar to what arch/powerpc/kernel/pci_64.c does
with hose->buid. I think that I had rather see the domain nr printed
whenever CONFIG_PCI_DOMAINS=y... oh well.
--
~Randy
*** Remember to use Documentation/SubmitChecklist when testing your code ***