Thread (45 messages) 45 messages, 10 authors, 2016-06-10

[PATCH V8 5/9] pci, acpi: add acpi hook to assign domain number.

From: Tomasz Nowicki <hidden>
Date: 2016-06-10 16:49:46
Also in: linux-acpi, linux-pci, lkml

On 10.06.2016 17:49, Lorenzo Pieralisi wrote:
On Fri, Jun 10, 2016 at 04:14:58PM +0100, Lorenzo Pieralisi wrote:
quoted
Hi Bjorn, Tomasz,

On Tue, Jun 07, 2016 at 07:15:59PM -0500, Bjorn Helgaas wrote:

[...]
quoted
quoted
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index eb431b5..2b52178 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -7,6 +7,7 @@
   *	Copyright 1997 -- 2000 Martin Mares <mj@ucw.cz>
   */

+#include <linux/acpi.h>
  #include <linux/kernel.h>
  #include <linux/delay.h>
  #include <linux/init.h>
@@ -4941,7 +4942,7 @@ int pci_get_new_domain_nr(void)
  }

  #ifdef CONFIG_PCI_DOMAINS_GENERIC
-void pci_bus_assign_domain_nr(struct pci_bus *bus, struct device *parent)
+static int of_pci_bus_domain_nr(struct device *parent)
Can we do a little cleanup before this patch?

   - pci_bus_assign_domain_nr() is only used inside drivers/pci, so
     maybe we move the prototype to drivers/pci/pci.h?

   - I don't really like the style of calling a function that
     internally assigns bus->domain_nr.  Could we do something like
     this instead?

     int pci_bus_domain_nr(...)
     {
       ...
       return domain;
     }

     ... pci_create_root_bus(...)
     {
       ...
       b->domain_nr = pci_bus_domain_nr(...);
We noticed while preparing v9, that this would force us to
write an empty pci_bus_domain_nr() prototype for
!PCI_DOMAINS_GENERIC (ie every arch but ARM/ARM64) that should
return 0 to keep current behaviour unchanged.

That's why pci_bus_assign_domain_nr() was there, so that it
was compiled out on !PCI_DOMAINS_GENERIC.

I really would like v9 to be final so let's fix it before posting it
shortly please.

For the above we have three options:

1) Leave code as-is in v8

2) in pci_create_root_bus():
#ifdef CONFIG_PCI_DOMAINS_GENERIC
        b->domain_nr = pci_bus_domain_nr(...);
#endif

+ other changes requested above

3) in pci_create_root_bus()

b->domain_nr = pci_bus_domain_nr(...);

unguarded and a stub:

#ifndef CONFIG_PCI_DOMAINS_GENERIC
static inline int pci_bus_domain_nr() { return 0; }
#endif

+ other changes requested above
Actually, Tomasz made me notice that pci_bus.domain_nr is
only declared for CONFIG_PCI_DOMAINS_GENERIC so (3) is not
even an option and IMO (2) is not much nicer than code in
v8 as-is with an ifdef in the middle of pci_create_root_bus().
To me (1) is nicer too. Bjorn what is your take on this? This is last 
bit before sending v9.

Thanks,
Tomasz
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help