On 2015/7/7 7:39, Yinghai Lu wrote: > Need to increase size to make sure it could fit all alt entries. > > In the patch, we first select one big size, and then keep reducing > the size and retrying to get the minimum value for alt_size. > > Example: > two bridges: one have 8M/8M, and 1M/1M children res. > one have 4M/4M, and 1M/1M children res. > > Then we have child pridges alt_align/alt_size: 8M/9M, 4M/5M. > Before this patch, parent bridge alt_align/alt_size is 8M/14M > that is wrong. > With this patch parent bridge alt_align/alt_size: 8M/17M. > > At same time, child bridges must align/size: 4M/12M, 2M/6M. > and prarent bridge must align/size: 4M/20M. > > So at last, we use 8M/17M as parent bridge alt_align/alt_size. Tested-by: Yijing Wang <wangyijing@xxxxxxxxxx> Hi Yinghai, does this patch depend on the previous items in this patchset ? Could you provide another version of this patch for stable branch, eg. 3.10 stable ? Thanks! Yijing. > > Link: https://bugzilla.kernel.org/show_bug.cgi?id=100451 > Reported-by: Yijing Wang <wangyijing@xxxxxxxxxx> > Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx> > --- > drivers/pci/setup-bus.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 53 insertions(+) > > diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c > index c0090d4..9427baa 100644 > --- a/drivers/pci/setup-bus.c > +++ b/drivers/pci/setup-bus.c > @@ -1304,6 +1304,47 @@ out: > return good_align; > } > > +static resource_size_t calculate_mem_alt_size(struct list_head *head, > + resource_size_t max_align, resource_size_t size, > + resource_size_t align_low) > +{ > + struct align_test_res *p; > + resource_size_t tmp; > + resource_size_t good_size, bad_size; > + int count = 0, order; > + > + good_size = ALIGN(size, align_low); > + > + list_for_each_entry(p, head, list) > + count++; > + > + if (count <= 1) > + goto out; > + > + __sort_align_test(head); > + > + tmp = max(size, max_align); > + order = __fls(count); > + if ((1ULL << order) < count) > + order++; > + good_size = ALIGN((tmp << order), align_low); > + bad_size = ALIGN(size, align_low) - align_low; > + size = good_size; > + while (size > bad_size) { > + /* check if align/size fit all entries */ > + if (is_align_size_good(head, max_align, size, 0)) > + good_size = size; > + else > + bad_size = size; > + > + size = bad_size + ((good_size - bad_size) >> 1); > + size = round_down(size, align_low); > + } > + > +out: > + return good_size; > +} > + > static inline bool is_optional(int i) > { > > @@ -1350,6 +1391,7 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask, > mask | IORESOURCE_PREFETCH, type); > LIST_HEAD(align_test_list); > LIST_HEAD(align_test_add_list); > + LIST_HEAD(align_test_alt_list); > resource_size_t alt_size = 0, alt_align = 0; > resource_size_t window_align; > > @@ -1418,6 +1460,10 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask, > > dev_res = res_to_dev_res(realloc_head, r); > if (dev_res && dev_res->alt_size) { > + add_to_align_test_list( > + &align_test_alt_list, > + dev_res->alt_align, > + dev_res->alt_size); > alt_size += dev_res->alt_size; > if (alt_align < dev_res->alt_align) > alt_align = dev_res->alt_align; > @@ -1440,6 +1486,12 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask, > alt_align = max_align; > alt_size = calculate_memsize(size, min_size, > 0, window_align); > + } else { > + /* need to increase size to fit more alt */ > + alt_align = max(alt_align, window_align); > + alt_size = calculate_mem_alt_size(&align_test_alt_list, > + alt_align, alt_size, > + window_align); > } > /* must is better ? */ > if (alt_size >= size0) { > @@ -1447,6 +1499,7 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask, > alt_size = size0; > } > } > + free_align_test_list(&align_test_alt_list); > > if (sum_add_size == size) > sum_add_size = add_size; > -- Thanks! Yijing -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
