On Thu, Jul 25, 2013 at 7:31 AM, Yinghai Lu <yinghai@xxxxxxxxxx> wrote:
> BenH reported that there are assign unassigned resource problems
> in powerpc.
>
> It turns out after
> | commit 0c5be0cb0edfe3b5c4b62eac68aa2aa15ec681af
> | Date: Thu Feb 23 19:23:29 2012 -0800
> |
> | PCI: Retry on IORESOURCE_IO type allocations
>
> even for root bus that does not have io port range, it will keep retrying
> to realloc with mmio after mmio allocation work in first try already.
>
> Current retry logic is : try with must+optional at first, and if
> it fails with any ioport or mmio, it will try must then try to extend
> must with optional. The reassign will put extended mmio or pref mmio
> in the middle of parent resource range.
> That will prevent other sibling resources from getting must-have resources
> or get extended properly.
>
> We can check fail type to see if can we need fall back to must-have
> for it only, that will keep others type to keep resource to have
> must+optional allocations.
>
> Separate three resource type checking if we need to release
> assigned resource after requested + add_size try.
> 1. if there is io port assign fail, will release assigned io port.
> 2. if there is pref mmio assign fail, release assigned pref mmio.
> if assigned pref mmio's parent is non-pref mmio and there
> is non-pref mmio assign fail, will release that assigned pref mmio.
> 3. if there is non-pref mmio assign fail or pref mmio assigned fail,
> will release assigned non-pref mmio.
>
> This will be become more often when we have x86 8 sockets or 32 sockets
> system, and those systems will have one root bus per socket.
> They will have some root buses that do not have ioport range or 32bit mmio.
>
> -v2: need to remove assigned entries from optional list too.
> -v3: not just checking ioport related, requested by Bjorn.
>
> Reported-by: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
I forgot; is there a mailing list archive URL for this report?
And did you say this should go to stable for v3.10+? If that's the
case, this should probably go in my for-linus branch for v3.11 instead
of waiting for v3.12, right?
> Tested-by: Gavin Shan <shangw@xxxxxxxxxxxxxxxxxx>
> Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
>
> ---
> drivers/pci/setup-bus.c | 70 +++++++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 69 insertions(+), 1 deletion(-)
>
> Index: linux-2.6/drivers/pci/setup-bus.c
> ===================================================================
> --- linux-2.6.orig/drivers/pci/setup-bus.c
> +++ linux-2.6/drivers/pci/setup-bus.c
> @@ -300,6 +300,48 @@ static void assign_requested_resources_s
> }
> }
>
> +static unsigned long pci_fail_res_type_mask(struct list_head *fail_head)
> +{
> + struct pci_dev_resource *fail_res;
> + unsigned long mask = 0;
> +
> + /* check failed type */
> + list_for_each_entry(fail_res, fail_head, list)
> + mask |= fail_res->flags;
> +
> + /*
> + * one pref failed resource will set IORESOURCE_MEM,
> + * as we can allocate pref in non-pref range.
> + * Will release all asssigned non-pref sibling resources
> + * according to that bit.
> + */
> + return mask & (IORESOURCE_IO | IORESOURCE_MEM | IORESOURCE_PREFETCH);
> +}
> +
> +static bool pci_need_to_release(unsigned long mask, struct resource *res)
> +{
> + if (res->flags & IORESOURCE_IO)
> + return !!(mask & IORESOURCE_IO);
> +
> + /* check pref at first */
> + if (res->flags & IORESOURCE_PREFETCH) {
> + if (mask & IORESOURCE_PREFETCH)
> + return true;
> + /* count pref if its parent is non-pref */
> + else if ((mask & IORESOURCE_MEM) &&
> + !(res->parent->flags & IORESOURCE_PREFETCH))
> + return true;
> + else
> + return false;
> + }
> +
> + if (res->flags & IORESOURCE_MEM)
> + return !!(mask & IORESOURCE_MEM);
> +
> + /* should not get here */
> + return false;
> +}
> +
> static void __assign_resources_sorted(struct list_head *head,
> struct list_head *realloc_head,
> struct list_head *fail_head)
> @@ -312,11 +354,24 @@ static void __assign_resources_sorted(st
> * if could do that, could get out early.
> * if could not do that, we still try to assign requested at first,
> * then try to reassign add_size for some resources.
> + *
> + * Separate three resource type checking if we need to release
> + * assigned resource after requested + add_size try.
> + * 1. if there is io port assign fail, will release assigned
> + * io port.
> + * 2. if there is pref mmio assign fail, release assigned
> + * pref mmio.
> + * if assigned pref mmio's parent is non-pref mmio and there
> + * is non-pref mmio assign fail, will release that assigned
> + * pref mmio.
> + * 3. if there is non-pref mmio assign fail or pref mmio
> + * assigned fail, will release assigned non-pref mmio.
> */
> LIST_HEAD(save_head);
> LIST_HEAD(local_fail_head);
> struct pci_dev_resource *save_res;
> - struct pci_dev_resource *dev_res;
> + struct pci_dev_resource *dev_res, *tmp_res;
> + unsigned long fail_type;
>
> /* Check if optional add_size is there */
> if (!realloc_head || list_empty(realloc_head))
> @@ -348,6 +403,19 @@ static void __assign_resources_sorted(st
> return;
> }
>
> + /* check failed type */
> + fail_type = pci_fail_res_type_mask(&local_fail_head);
> + /* remove not need to be released assigned res from head list etc */
> + list_for_each_entry_safe(dev_res, tmp_res, head, list)
> + if (dev_res->res->parent &&
> + !pci_need_to_release(fail_type, dev_res->res)) {
> + /* remove it from realloc_head list */
> + remove_from_list(realloc_head, dev_res->res);
> + remove_from_list(&save_head, dev_res->res);
> + list_del(&dev_res->list);
> + kfree(dev_res);
> + }
> +
> free_list(&local_fail_head);
> /* Release assigned resource */
> list_for_each_entry(dev_res, head, list)
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