On system with several pcie switches, BIOS allocate very tight resources to the bar, and it is not aligned to min_align as kernel allocation code.
For example: 02:03.0---0c:00.0---0d:04.0---18:00.0 18:00.0 need 0x10000000, and 0x00010000. BIOS only allocate 0x10100000 to 0d:04.0 and above bridges. Later after using /sys to remove 0c:00.0, rescan with /sys/bus/pci/rescan can not allocate 0x18000000 to 0c:00.0. another example: 00:1c.0-[02-21]----00.0-[03-21]--+-01.0-[04-12]----00.0-[05-12]----19.0-[06-12]----00.0 +-05.0-[13]-- +-07.0-[14-20]----00.0-[15-20]--+-08.0-[16]--+-00.0 | | \-00.1 | +-14.0-[17]----00.0 | \-19.0-[18-20]----00.0 \-09.0-[21]-- 06:00.0 need 0x4000000 and 0x800000. BIOS only allocate 0x4800000 to 05:19.0 and 04:00.0. when 05:19.0 get removed via /sys, and rescan will /sys/bus/pci/rescan will fail. pci 0000:05:19.0: BAR 14: no space for [mem size 0x06000000] pci 0000:05:19.0: BAR 14: failed to assign [mem size 0x06000000] pci 0000:06:00.0: BAR 2: no space for [mem size 0x04000000 64bit] pci 0000:06:00.0: BAR 2: failed to assign [mem size 0x04000000 64bit] pci 0000:06:00.0: BAR 0: no space for [mem size 0x00800000] pci 0000:06:00.0: BAR 0: failed to assign [mem size 0x00800000] current code try to use align 0x2000000 and size 0x6000000, but parent bridge only have 0x4800000. Introduce alt_align/alt_size and store in realloc list in addition to addon info, and will try it after min_align/min_size allocation fails. The alt_align is max_align, and alt_size is aligned size with bridge minimum window alignment. on my test setup: 00:1c.7---61:00.0---62:00.0 62:00.0 needs 0x800000 and 0x20000. and 00:1c.7 only have 9M allocated for mmio, with this patch we have pci 0000:61:00.0: bridge window [mem 0x00400000-0x00ffffff] to [bus 62] add_size 0 add_align 0 alt_size 900000 alt_align 800000 must_size c00000 must_align 400000 pci 0000:61:00.0: BAR 14: no space for [mem size 0x00c00000] pci 0000:61:00.0: BAR 14: failed to assign [mem size 0x00c00000] pci 0000:61:00.0: BAR 14: assigned [mem 0xdf000000-0xdf8fffff] pci 0000:62:00.0: BAR 0: assigned [mem 0xdf000000-0xdf7fffff pref] pci 0000:62:00.0: BAR 1: assigned [mem 0xdf800000-0xdf81ffff] pci 0000:61:00.0: PCI bridge to [bus 62] pci 0000:61:00.0: bridge window [io 0x6000-0x6fff] pci 0000:61:00.0: bridge window [mem 0xdf000000-0xdf8fffff] pci 0000:00:1c.7: PCI bridge to [bus 61-68] pci 0000:00:1c.7: bridge window [io 0x6000-0x6fff] pci 0000:00:1c.7: bridge window [mem 0xdf000000-0xdf8fffff] so for 61:00.0 first try with 12M fails, and second try with 9M the alt_size works. Later 62:00.0 get correct resource allocated too. Link: https://bugzilla.kernel.org/show_bug.cgi?id=100451 Reported-by: Yijing Wang <wangyij...@huawei.com> Signed-off-by: Yinghai Lu <ying...@kernel.org> --- drivers/pci/setup-bus.c | 192 +++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 175 insertions(+), 17 deletions(-) diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c index e2aedac..c0090d4 100644 --- a/drivers/pci/setup-bus.c +++ b/drivers/pci/setup-bus.c @@ -331,7 +331,7 @@ static void reassign_resources_sorted(struct list_head *realloc_head, { struct resource *res; struct pci_dev_resource *add_res, *tmp; - resource_size_t add_size, align; + resource_size_t add_size, align, r_size; int idx; list_for_each_entry_safe(add_res, tmp, realloc_head, list) { @@ -347,12 +347,19 @@ static void reassign_resources_sorted(struct list_head *realloc_head, idx = res - &add_res->dev->resource[0]; add_size = add_res->add_size; align = add_res->min_align; - if (!resource_size(res)) { + if (!add_size || !align) /* alt_size only */ + goto out; + + r_size = resource_size(res); + if (!r_size) { res->start = align; res->end = res->start + add_size - 1; if (pci_assign_resource(add_res->dev, idx)) reset_resource(res); } else { + /* could just assigned with alt, add difference ? */ + if (r_size < add_res->must_size) + add_size += add_res->must_size - r_size; res->flags |= add_res->flags & (IORESOURCE_STARTALIGN|IORESOURCE_SIZEALIGN); if (pci_reassign_resource(add_res->dev, idx, @@ -393,7 +400,7 @@ static void assign_requested_resources_sorted(struct list_head *head, list_for_each_entry(dev_res, head, list) { res = dev_res->res; idx = res - &dev_res->dev->resource[0]; - if (resource_size(res) && + if (!res->parent && resource_size(res) && pci_assign_resource(dev_res->dev, idx)) { if (fail_head) add_to_list(fail_head, dev_res->dev, res); @@ -435,7 +442,6 @@ static bool pci_need_to_release(unsigned long mask, struct resource *res) * 3. if there is non-pref mmio assign fail or pref mmio * assigned fail, will release assigned non-pref mmio. */ - if (res->flags & IORESOURCE_IO) return !!(mask & IORESOURCE_IO); @@ -573,6 +579,98 @@ static bool __assign_resources_must_add_sorted(struct list_head *head, return false; } +static void __assign_resources_alt_sorted(struct list_head *head, + struct list_head *realloc_head, + struct list_head *local_fail_head) +{ + LIST_HEAD(save_head); + LIST_HEAD(local_alt_fail_head); + struct pci_dev_resource *dev_res; + struct pci_dev_resource *alt_res, *fail_res; + unsigned long fail_type; + struct resource *res; + int alt_count = 0; + + /* check if we have alt really */ + list_for_each_entry(dev_res, head, list) { + res = dev_res->res; + alt_res = res_to_dev_res(realloc_head, res); + if (!alt_res || !alt_res->alt_size) + continue; + + if (alt_res->must_size == alt_res->alt_size) + continue; + + alt_count++; + } + if (!alt_count) + return; + + /* check failed type */ + fail_type = pci_fail_res_type_mask(local_fail_head); + /* release resource with same type that failes */ + list_for_each_entry(dev_res, head, list) { + res = dev_res->res; + if (res->parent) { + if (!pci_need_to_release(fail_type, res)) + continue; + + dev_printk(KERN_DEBUG, &dev_res->dev->dev, + "BAR %d: released %pR\n", + (int)(res - &dev_res->dev->resource[0]), + res); + release_resource(dev_res->res); + /* put into fail list */ + add_to_list(local_fail_head, dev_res->dev, res); + reset_resource(res); + } + + alt_res = res_to_dev_res(realloc_head, res); + if (!alt_res || !alt_res->alt_size) + continue; + + fail_res = res_to_dev_res(local_fail_head, res); + if (!fail_res) /* should not happen */ + continue; + + res->flags = fail_res->flags; + if (res->flags & IORESOURCE_STARTALIGN) + res->start = alt_res->alt_align; + else + res->start = 0; + res->end = res->start + alt_res->alt_size - 1; + } + + __sort_resources(head); + /* Satisfy the alt resource requests */ + assign_requested_resources_sorted(head, &local_alt_fail_head); + + /* update local fail list */ + list_for_each_entry(dev_res, head, list) + if (dev_res->res->parent) + remove_from_list(local_fail_head, dev_res->res); + list_for_each_entry(fail_res, local_fail_head, list) + remove_from_list(&local_alt_fail_head, fail_res->res); + list_for_each_entry(fail_res, &local_alt_fail_head, list) { + res = fail_res->res; + dev_res = res_to_dev_res(realloc_head, res); + if (!dev_res) /* should not happen */ + continue; + + /* change res back must and save to fail list */ + res->flags = fail_res->flags; + if (res->flags & IORESOURCE_STARTALIGN) + res->start = dev_res->must_align; + else + res->start = 0; + res->end = res->start + dev_res->must_size - 1; + + add_to_list(local_fail_head, fail_res->dev, res); + reset_resource(res); + } + free_list(&local_alt_fail_head); +} + static void __assign_resources_sorted(struct list_head *head, struct list_head *realloc_head, struct list_head *fail_head) @@ -589,6 +687,7 @@ static void __assign_resources_sorted(struct list_head *head, LIST_HEAD(save_head); LIST_HEAD(local_fail_head); + LIST_HEAD(local_alt_fail_head); /* Check must+optional add */ if (realloc_head && @@ -598,12 +697,22 @@ static void __assign_resources_sorted(struct list_head *head, __sort_resources(head); /* Satisfy the must-have resource requests */ - assign_requested_resources_sorted(head, fail_head); + assign_requested_resources_sorted(head, &local_fail_head); - /* Try to satisfy any additional optional resource - requests */ + /* alt */ + if (realloc_head && !list_empty(&local_fail_head)) + __assign_resources_alt_sorted(head, realloc_head, + &local_fail_head); + + /* Try to satisfy any additional optional resource requests */ if (realloc_head) reassign_resources_sorted(realloc_head, head); + + if (fail_head) + list_splice_tail(&local_fail_head, fail_head); + else + free_list(&local_fail_head); + free_list(head); } @@ -1241,10 +1350,14 @@ 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); + resource_size_t alt_size = 0, alt_align = 0; + resource_size_t window_align; if (!b_res) return -ENOSPC; + window_align = window_alignment(bus, b_res->flags); + list_for_each_entry(dev, &bus->devices, bus_list) { int i; @@ -1289,6 +1402,7 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask, if (realloc_head) { resource_size_t add_r_size, add_align; + struct pci_dev_resource *dev_res; add_r_size = get_res_add_size(realloc_head, r); add_align = get_res_add_align(realloc_head, r); @@ -1301,19 +1415,39 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask, sum_add_size += r_size + add_r_size; if (add_align > max_add_align) max_add_align = add_align; + + dev_res = res_to_dev_res(realloc_head, r); + if (dev_res && dev_res->alt_size) { + alt_size += dev_res->alt_size; + if (alt_align < dev_res->alt_align) + alt_align = dev_res->alt_align; + } } } } - max_align = max(max_align, window_alignment(bus, b_res->flags)); + max_align = max(max_align, window_align); if (size || min_size) { min_align = calculate_mem_align(&align_test_list, max_align, - size, window_alignment(bus, b_res->flags)); + size, window_align); size0 = calculate_memsize(size, min_size, resource_size(b_res), min_align); } free_align_test_list(&align_test_list); + if (size0 && realloc_head) { + if (!alt_size) { + alt_align = max_align; + alt_size = calculate_memsize(size, min_size, + 0, window_align); + } + /* must is better ? */ + if (alt_size >= size0) { + alt_align = min_align; + alt_size = size0; + } + } + if (sum_add_size == size) sum_add_size = add_size; else if (add_size > sum_add_size - size) @@ -1321,7 +1455,7 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask, if (sum_add_size > size && realloc_head) { min_add_align = calculate_mem_align(&align_test_add_list, max_add_align, sum_add_size, - window_alignment(bus, b_res->flags)); + window_align); size1 = calculate_memsize(sum_add_size, min_size, resource_size(b_res), min_add_align); } @@ -1337,13 +1471,37 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask, b_res->start = min_align; 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_add_align, 0, 0, size0, min_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), - (unsigned long long) min_add_align); + if (realloc_head) { + resource_size_t final_add_size = 0; + + if (size1 > size0) + final_add_size = size1 - size0; + else + min_add_align = 0; + + /* + * realloc list include three type entries + * 1. optional only: + * add_size != 0, alt_size == 0, must_size == 0 + * 2. must only: + * add_size == 0, alt_size != 0, alt_size <= must_size + * 3. must + optional: + * add_size != 0, alt_size != 0, alt_size <= must_size + */ + if (final_add_size || alt_size) { + __add_to_list(realloc_head, bus->self, b_res, + final_add_size, min_add_align, + alt_size, alt_align, size0, min_align); + dev_printk(KERN_DEBUG, &bus->self->dev, + "bridge window %pR to %pR add_size %llx add_align %llx alt_size %llx alt_align %llx must_size %llx must_align %llx\n", + b_res, &bus->busn_res, + (unsigned long long)final_add_size, + (unsigned long long)min_add_align, + (unsigned long long)alt_size, + (unsigned long long)alt_align, + (unsigned long long)size0, + (unsigned long long)min_align); + } } return 0; } -- 1.8.4.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/