Re: [PATCH 2/2] pci: reserve extra bus resource for hotplug bridge

[Taku Izumi <izumi.taku@jp.fujitsu.com>]

On Tue, 3 Jul 2012 21:06:53 -0700
Yinghai Lu <yinghai@kernel.org> wrote:

> On Tue, Jul 3, 2012 at 8:16 PM, Taku Izumi <izumi.taku@jp.fujitsu.com> wrote:
> >
> > Currently I/O ports and I/O memory resources are reserved for
> > hotplug bridges and we can tune their size by using hpiosize
> > and hpmemsize boot option.
> >
> > This patch extends feature so that we can reserve additional
> > bus number resources for hotplug bridges and tune it by
> > using "hpbussize" option.
> >
> > Signed-off-by: Taku Izumi <izumi.taku@jp.fujitsu.com>
> > ---
> >  Documentation/kernel-parameters.txt |    4 ++++
> >  drivers/pci/pci.c                   |    6 +++++-
> >  drivers/pci/probe.c                 |    4 ++++
> >  include/linux/pci.h                 |    1 +
> >  4 files changed, 14 insertions(+), 1 deletion(-)
> >
> > Index: linux/drivers/pci/pci.c
> > ===================================================================
> > --- linux.orig/drivers/pci/pci.c        2012-06-26 14:37:22.000000000 +0900
> > +++ linux/drivers/pci/pci.c     2012-07-04 10:00:50.708002757 +0900
> > @@ -74,9 +74,11 @@ unsigned long pci_cardbus_mem_size = DEF
> >
> >  #define DEFAULT_HOTPLUG_IO_SIZE                (256)
> >  #define DEFAULT_HOTPLUG_MEM_SIZE       (2*1024*1024)
> > -/* pci=hpmemsize=nnM,hpiosize=nn can override this */
> > +#define DEFAULT_HOTPLUG_BUS_SIZE       (0)
> > +/* pci=hpmemsize=nnM,hpiosize=nn,hpbussize=n can override this */
> >  unsigned long pci_hotplug_io_size  = DEFAULT_HOTPLUG_IO_SIZE;
> >  unsigned long pci_hotplug_mem_size = DEFAULT_HOTPLUG_MEM_SIZE;
> > +unsigned int pci_hotplug_bus_size = DEFAULT_HOTPLUG_BUS_SIZE;
> >
> >  enum pcie_bus_config_types pcie_bus_config = PCIE_BUS_TUNE_OFF;
> >
> > @@ -4022,6 +4024,8 @@ static int __init pci_setup(char *str)
> >                                 pci_hotplug_io_size = memparse(str + 9, &str);
> >                         } else if (!strncmp(str, "hpmemsize=", 10)) {
> >                                 pci_hotplug_mem_size = memparse(str + 10, &str);
> > +                       } else if (!strncmp(str, "hpbussize=", 10)) {
> > +                               pci_hotplug_bus_size = memparse(str + 10, &str);
> >                         } else if (!strncmp(str, "pcie_bus_tune_off", 17)) {
> >                                 pcie_bus_config = PCIE_BUS_TUNE_OFF;
> >                         } else if (!strncmp(str, "pcie_bus_safe", 13)) {
> > Index: linux/drivers/pci/probe.c
> > ===================================================================
> > --- linux.orig/drivers/pci/probe.c      2012-06-26 14:37:22.000000000 +0900
> > +++ linux/drivers/pci/probe.c   2012-07-04 10:00:50.718002632 +0900
> > @@ -867,6 +867,10 @@ int __devinit pci_scan_bridge(struct pci
> >                 /*
> >                  * Set the subordinate bus number to its real value.
> >                  */
> > +               if (dev->is_hotplug_bridge) {
> > +                       if (max + pci_hotplug_bus_size < child->busn_res.end)
> > +                               max += pci_hotplug_bus_size;
> > +               }
> 
> again, that adding is not safe.
> 
> please drop this one now.
>
> or you can prepare one against busn_alloc and I put new version in the
> busn_alloc branch.

 OK, I'll do it. 


Best regards,
Taku Izumi <izumi.taku@jp.fujitsu.com>