| Message ID | 1464846411-16895-3-git-send-email-xyjxie@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
On Thu, Jun 02, 2016 at 01:46:49PM +0800, Yongji Xie wrote: > Now we use the IORESOURCE_STARTALIGN to identify bridge resources > in __assign_resources_sorted(). That's quite fragile. We can't > make sure that the PCI devices' resources will not use > IORESOURCE_STARTALIGN any more. Can you explain this a little more? I don't quite understand the problem. Maybe you can give an example of the problem? > In this patch, we try to use a more robust way to identify > bridge resources. > > Signed-off-by: Yongji Xie <xyjxie@linux.vnet.ibm.com> > --- > drivers/pci/setup-bus.c | 9 ++++++--- > 1 file changed, 6 insertions(+), 3 deletions(-) > > diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c > index 55641a3..216ddbc 100644 > --- a/drivers/pci/setup-bus.c > +++ b/drivers/pci/setup-bus.c > @@ -390,6 +390,7 @@ static void __assign_resources_sorted(struct list_head *head, > struct pci_dev_resource *dev_res, *tmp_res, *dev_res2; > unsigned long fail_type; > resource_size_t add_align, align; > + int index; > > /* Check if optional add_size is there */ > if (!realloc_head || list_empty(realloc_head)) > @@ -410,11 +411,13 @@ static void __assign_resources_sorted(struct list_head *head, > > /* > * There are two kinds of additional resources in the list: > - * 1. bridge resource -- IORESOURCE_STARTALIGN > - * 2. SR-IOV resource -- IORESOURCE_SIZEALIGN > + * 1. bridge resource > + * 2. SR-IOV resource > * Here just fix the additional alignment for bridge > */ > - if (!(dev_res->res->flags & IORESOURCE_STARTALIGN)) > + index = dev_res->res - dev_res->dev->resource; > + if (index < PCI_BRIDGE_RESOURCES || > + index > PCI_BRIDGE_RESOURCE_END) I think the code looks OK; at least, it seems to match the comment. I'd just like to understand the problem a little better. > continue; > > add_align = get_res_add_align(realloc_head, dev_res->res); > -- > 1.7.9.5 > -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 2016/6/21 9:50, Bjorn Helgaas wrote: > On Thu, Jun 02, 2016 at 01:46:49PM +0800, Yongji Xie wrote: >> Now we use the IORESOURCE_STARTALIGN to identify bridge resources >> in __assign_resources_sorted(). That's quite fragile. We can't >> make sure that the PCI devices' resources will not use >> IORESOURCE_STARTALIGN any more. > Can you explain this a little more? I don't quite understand the > problem. Maybe you can give an example of the problem? Now there are two kinds of additional resources in the list: bridge resource and SR-IOV resource. Here we just want to fix the additional alignment for bridge. But if SR-IOV resource get the flag IORESOURCE_STARTALIGN which is not only for bridge, the current check seems to be wrong. And kernel parameter "resource_alignment" could set IORESOURCE_STARTALIGN for SR-IOV resource with my next patch applied. Thanks, Yongji >> In this patch, we try to use a more robust way to identify >> bridge resources. >> >> Signed-off-by: Yongji Xie <xyjxie@linux.vnet.ibm.com> >> --- >> drivers/pci/setup-bus.c | 9 ++++++--- >> 1 file changed, 6 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c >> index 55641a3..216ddbc 100644 >> --- a/drivers/pci/setup-bus.c >> +++ b/drivers/pci/setup-bus.c >> @@ -390,6 +390,7 @@ static void __assign_resources_sorted(struct list_head *head, >> struct pci_dev_resource *dev_res, *tmp_res, *dev_res2; >> unsigned long fail_type; >> resource_size_t add_align, align; >> + int index; >> >> /* Check if optional add_size is there */ >> if (!realloc_head || list_empty(realloc_head)) >> @@ -410,11 +411,13 @@ static void __assign_resources_sorted(struct list_head *head, >> >> /* >> * There are two kinds of additional resources in the list: >> - * 1. bridge resource -- IORESOURCE_STARTALIGN >> - * 2. SR-IOV resource -- IORESOURCE_SIZEALIGN >> + * 1. bridge resource >> + * 2. SR-IOV resource >> * Here just fix the additional alignment for bridge >> */ >> - if (!(dev_res->res->flags & IORESOURCE_STARTALIGN)) >> + index = dev_res->res - dev_res->dev->resource; >> + if (index < PCI_BRIDGE_RESOURCES || >> + index > PCI_BRIDGE_RESOURCE_END) > I think the code looks OK; at least, it seems to match the comment. > I'd just like to understand the problem a little better. > >> continue; >> >> add_align = get_res_add_align(realloc_head, dev_res->res); >> -- >> 1.7.9.5 >> > _______________________________________________ > Linuxppc-dev mailing list > Linuxppc-dev@lists.ozlabs.org > https://lists.ozlabs.org/listinfo/linuxppc-dev -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c index 55641a3..216ddbc 100644 --- a/drivers/pci/setup-bus.c +++ b/drivers/pci/setup-bus.c @@ -390,6 +390,7 @@ static void __assign_resources_sorted(struct list_head *head, struct pci_dev_resource *dev_res, *tmp_res, *dev_res2; unsigned long fail_type; resource_size_t add_align, align; + int index; /* Check if optional add_size is there */ if (!realloc_head || list_empty(realloc_head)) @@ -410,11 +411,13 @@ static void __assign_resources_sorted(struct list_head *head, /* * There are two kinds of additional resources in the list: - * 1. bridge resource -- IORESOURCE_STARTALIGN - * 2. SR-IOV resource -- IORESOURCE_SIZEALIGN + * 1. bridge resource + * 2. SR-IOV resource * Here just fix the additional alignment for bridge */ - if (!(dev_res->res->flags & IORESOURCE_STARTALIGN)) + index = dev_res->res - dev_res->dev->resource; + if (index < PCI_BRIDGE_RESOURCES || + index > PCI_BRIDGE_RESOURCE_END) continue; add_align = get_res_add_align(realloc_head, dev_res->res);
Now we use the IORESOURCE_STARTALIGN to identify bridge resources in __assign_resources_sorted(). That's quite fragile. We can't make sure that the PCI devices' resources will not use IORESOURCE_STARTALIGN any more. In this patch, we try to use a more robust way to identify bridge resources. Signed-off-by: Yongji Xie <xyjxie@linux.vnet.ibm.com> --- drivers/pci/setup-bus.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)