Bjorn,
Is my understanding correct? Could I send another version based on your
comment, so that we can see it meets your requirement?
On Wed, Aug 20, 2014 at 02:14:02PM +0800, Wei Yang wrote:
>On Tue, Aug 19, 2014 at 09:08:41PM -0600, Bjorn Helgaas wrote:
>>On Thu, Jul 24, 2014 at 02:22:14PM +0800, Wei Yang wrote:
>>> At resource sizing/assigning stage, resources are divided into two lists,
>>> requested list and additional list, while the alignement of the additional
>>> IOV BAR is not taken into the sizeing and assigning procedure.
>>>
>>> This is reasonable in the original implementation, since IOV BAR's alignment is
>>> mostly the size of a PF BAR alignemt. This means the alignment is already taken
>>> into consideration. While this rule may be violated on some platform.
>>>
>>> This patch take the additional IOV BAR alignment in sizing and assigning stage
>>> explicitly.
>>>
>>> Signed-off-by: Wei Yang <weiyang@xxxxxxxxxxxxxxxxxx>
>>> ---
>>> drivers/pci/setup-bus.c | 68 +++++++++++++++++++++++++++++++++++++++++------
>>> 1 file changed, 60 insertions(+), 8 deletions(-)
>>>
>>> diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
>>> index a5a63ec..d83681f 100644
>>> --- a/drivers/pci/setup-bus.c
>>> +++ b/drivers/pci/setup-bus.c
>>> @@ -120,6 +120,28 @@ static resource_size_t get_res_add_size(struct list_head *head,
>>> return 0;
>>> }
>>>
>>> +static resource_size_t get_res_add_align(struct list_head *head,
>>> + struct resource *res)
>>> +{
>>> + struct pci_dev_resource *dev_res;
>>> +
>>> + list_for_each_entry(dev_res, head, list) {
>>> + if (dev_res->res == res) {
>>> + int idx = res - &dev_res->dev->resource[0];
>>> +
>>> + dev_printk(KERN_DEBUG, &dev_res->dev->dev,
>>> + "res[%d]=%pR get_res_add_align min_align %llx\n",
>>> + idx, dev_res->res,
>>> + (unsigned long long)dev_res->min_align);
>>> +
>>> + return dev_res->min_align;
>>> + }
>>> + }
>>> +
>>> + return 0;
>>> +}
>>
>>I see that you copied the structure of the existing get_res_add_size()
>>here. But I don't understand *that* function. It looks basically like
>>this:
>>
>> resource_size_t get_res_add_size(list, res)
>> {
>> list_for_each_entry(dev_res, head, list) {
>> if (dev_res->res == res)
>> return dev_res->add_size;
>> }
>> return 0;
>> }
>>
>>and we call it like this:
>>
>> dev_res->res->end += get_res_add_size(realloc_head, dev_res->res);
>>
>>So we start out with dev_res", pass in dev_res->res, search the
>>realloc_head list to find dev_res again, and return dev_res->add_size.
>>That looks equivalent to just:
>>
>> dev_res->res->end += dev_res->add_size;
>>
>>It looks like get_res_add_size() merely adds a printk and some complexity.
>>Am I missing something?
>>
>
>Let me try to explain it, if not correct, please let know :-)
>
> dev_res->res->end += get_res_add_size(realloc_head, dev_res->res);
>
>would be expanded to:
>
> dev_res->res->end += dev_res_1->add_size;
>
>with the dev_res_1 is another one from dev_res which is stored in realloc_head.
>
>>I do see that there are other callers where we don't actually start with
>>dev_res, which makes it a little more complicated. But I think you should
>>either add something like this:
>>
>> struct pci_dev_resource *res_to_dev_res(list, res)
>> {
>> list_for_each_entry(dev_res, head, list) {
>> if (dev_res->res == res)
>> return dev_res;
>> }
>> return NULL;
>> }
>>
>
>Ok, we can extract the common part of these two functions.
>
>>which can be used to replace get_res_add_size() and get_res_add_align(), OR
>>figure out whether the dev_res of interest is always one we've just added.
>>If it is, maybe you can just make add_to_list() return the dev_res pointer
>>instead of an errno, and hang onto the pointer. I'd like that much better
>>if that's possible.
>>
>
>Sorry, I don't get this point.
>
>add_to_list() is used to create the pci_dev_resource list, get_res_add_size()
>and get_res_add_align() is to retrieve the information in the list. I am not
>sure how to leverage add_to_list() in these two functions?
>
>>> +
>>> +
>>> /* Sort resources by alignment */
>>> static void pdev_sort_resources(struct pci_dev *dev, struct list_head *head)
>>> {
>>> @@ -368,8 +390,9 @@ static void __assign_resources_sorted(struct list_head *head,
>>> LIST_HEAD(save_head);
>>> LIST_HEAD(local_fail_head);
>>> struct pci_dev_resource *save_res;
>>> - struct pci_dev_resource *dev_res, *tmp_res;
>>> + struct pci_dev_resource *dev_res, *tmp_res, *dev_res2;
>>> unsigned long fail_type;
>>> + resource_size_t add_align, align;
>>>
>>> /* Check if optional add_size is there */
>>> if (!realloc_head || list_empty(realloc_head))
>>> @@ -384,10 +407,31 @@ static void __assign_resources_sorted(struct list_head *head,
>>> }
>>>
>>> /* Update res in head list with add_size in realloc_head list */
>>> - list_for_each_entry(dev_res, head, list)
>>> + list_for_each_entry_safe(dev_res, tmp_res, head, list) {
>>> dev_res->res->end += get_res_add_size(realloc_head,
>>> dev_res->res);
>>>
>>> + if (!(dev_res->res->flags & IORESOURCE_STARTALIGN))
>>> + continue;
>>> +
>>> + add_align = get_res_add_align(realloc_head, dev_res->res);
>>> +
>>> + if (add_align > dev_res->res->start) {
>>> + dev_res->res->start = add_align;
>>> + dev_res->res->end = add_align +
>>> + resource_size(dev_res->res);
>>> +
>>> + list_for_each_entry(dev_res2, head, list) {
>>> + align = pci_resource_alignment(dev_res2->dev,
>>> + dev_res2->res);
>>> + if (add_align > align)
>>> + list_move_tail(&dev_res->list,
>>> + &dev_res2->list);
>>> + }
>>> + }
>>> +
>>> + }
>>> +
>>> /* Try updated head list with add_size added */
>>> assign_requested_resources_sorted(head, &local_fail_head);
>>>
>>> @@ -930,6 +974,8 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
>>> struct resource *b_res = find_free_bus_resource(bus,
>>> mask | IORESOURCE_PREFETCH, type);
>>> resource_size_t children_add_size = 0;
>>> + resource_size_t children_add_align = 0;
>>> + resource_size_t add_align = 0;
>>>
>>> if (!b_res)
>>> return -ENOSPC;
>>> @@ -954,6 +1000,7 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
>>> /* put SRIOV requested res to the optional list */
>>> if (realloc_head && i >= PCI_IOV_RESOURCES &&
>>> i <= PCI_IOV_RESOURCE_END) {
>>> + add_align = max(pci_resource_alignment(dev, r), add_align);
>>> r->end = r->start - 1;
>>> add_to_list(realloc_head, dev, r, r_size, 0/* don't care */);
>>> children_add_size += r_size;
>>> @@ -984,8 +1031,11 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
>>> if (order > max_order)
>>> max_order = order;
>>>
>>> - if (realloc_head)
>>> + if (realloc_head) {
>>> children_add_size += get_res_add_size(realloc_head, r);
>>> + children_add_align = get_res_add_align(realloc_head, r);
>>> + add_align = max(add_align, children_add_align);
>>> + }
>>> }
>>> }
>>>
>>> @@ -996,7 +1046,7 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
>>> add_size = children_add_size;
>>> size1 = (!realloc_head || (realloc_head && !add_size)) ? size0 :
>>> calculate_memsize(size, min_size, add_size,
>>> - resource_size(b_res), min_align);
>>> + resource_size(b_res), max(min_align, add_align));
>>> if (!size0 && !size1) {
>>> if (b_res->start || b_res->end)
>>> dev_info(&bus->self->dev, "disabling bridge window %pR to %pR (unused)\n",
>>> @@ -1008,10 +1058,12 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
>>> b_res->end = size0 + min_align - 1;
>>> b_res->flags |= IORESOURCE_STARTALIGN;
>>> if (size1 > size0 && realloc_head) {
>>> - add_to_list(realloc_head, bus->self, b_res, size1-size0, min_align);
>>> - dev_printk(KERN_DEBUG, &bus->self->dev, "bridge window %pR to %pR add_size %llx\n",
>>> - b_res, &bus->busn_res,
>>> - (unsigned long long)size1-size0);
>>> + add_to_list(realloc_head, bus->self, b_res, size1-size0,
>>> + max(min_align, add_align));
>>> + dev_printk(KERN_DEBUG, &bus->self->dev, "bridge window "
>>> + "%pR to %pR add_size %llx add_align %llx\n", b_res,
>>> + &bus->busn_res, (unsigned long long)size1-size0,
>>> + max(min_align, add_align));
>>
>>Factor out this "max(min_align, add_align)" thing so we don't have to
>>change these lines. Bonus points if you can also factor it out of the
>>calculate_memsize() call above. That one is a pretty complicated ternary
>>expression that should probably be turned into an "if" instead anyway.
>>
>
>Ok, I get your point. Let me make it more easy to read.
>
>>> }
>>> return 0;
>>> }
>>> --
>>> 1.7.9.5
>>>
>
>--
>Richard Yang
>Help you, Help me
--
Richard Yang
Help you, Help me
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