lkml.org 
[lkml]   [2015]   [Mar]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v6 03/30] PCI: Export busn_resource to drivers/pci
On Mon, Mar 09, 2015 at 10:34:00AM +0800, Yijing Wang wrote:
> Export out busn_resource. Xen pcifront module need it.
>
> Signed-off-by: Yijing Wang <wangyijing@huawei.com>
> ---
> drivers/pci/pci.h | 2 ++
> drivers/pci/probe.c | 3 ++-
> 2 files changed, 4 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
> index 4091f82..eeacab9 100644
> --- a/drivers/pci/pci.h
> +++ b/drivers/pci/pci.h
> @@ -10,6 +10,8 @@ bool pcie_cap_has_lnkctl(const struct pci_dev *dev);
>
> /* Functions internal to the PCI core code */
>
> +extern struct resource busn_resource;
> +
> int pci_create_sysfs_dev_files(struct pci_dev *pdev);
> void pci_remove_sysfs_dev_files(struct pci_dev *pdev);
> #if !defined(CONFIG_DMI) && !defined(CONFIG_ACPI)
> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> index 8ef0375..b97ea81 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -17,12 +17,13 @@
> #define CARDBUS_LATENCY_TIMER 176 /* secondary latency timer */
> #define CARDBUS_RESERVE_BUSNR 3
>
> -static struct resource busn_resource = {
> +struct resource busn_resource = {
> .name = "PCI busn",
> .start = 0,
> .end = 255,
> .flags = IORESOURCE_BUS,
> };
> +EXPORT_SYMBOL(busn_resource);

I don't think this is a good idea. We support multiple PCI domains, and
each domain has its own 0-255 bus number range. This busn_resource is
only for domain 0 and probably should be handled in arch code instead of
the PCI core.

Right now, I think it's possible to call pci_scan_bus_parented() or
pci_scan_bus() several times for buses in different domains, and they would
all share the same busn_resource, which would cause corruption.

So it's already broken, but I don't want to make it harder to fix by
exporting this stuff.

>
> /* Ugh. Need to stop exporting this to modules. */
> LIST_HEAD(pci_root_buses);
> --
> 1.7.1
>


\
 
 \ /
  Last update: 2015-03-11 23:41    [W:0.307 / U:1.620 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site