x86: work around io allocation overlap of HT links

normally BIOSes assign io/mmio range to different HT links without
overlapping, even same node same link should get non overlapping
entries.

but Rafael L. Wysocki's buggy BIOS creates a link with overlapping
entries for mmio and io:

  node 0 link 0: io port [1000, ffffff]
  node 0 link 0: mmio [e0000000, efffffff]
  node 0 link 0: mmio [a0000, bffff]
  node 0 link 0: mmio [80000000, ffffffff]

try to merge them and we will get:

  bus: [00, ff] on node 0 link 0
  bus: 00 index 0 io port: [0, ffff]
  bus: 00 index 1 mmio: [80000000, fcffffffff]
  bus: 00 index 2 mmio: [a0000, bffff]

so later we will reduce the chance to assign used resource to
unassigned device.

Reported-by: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Tested-by: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 38 insertions, 18 deletions

diff --git a/arch/x86/pci/k8-bus_64.c b/arch/x86/pci/k8-bus_64.c
index 4e64c58e17a0..ab6d4b18a88f 100644
--- a/arch/x86/pci/k8-bus_64.c
+++ b/arch/x86/pci/k8-bus_64.c
@@ -112,17 +112,25 @@ static void __init update_range(struct res_range *range, size_t start,
         for (j = 0; j < RANGE_NUM; j++) {
                 if (!range[j].end)
                         continue;
-                if (start == range[j].start && end < range[j].end) {
-                        range[j].start = end + 1;
-                        break;
-                } else if (start == range[j].start && end == range[j].end) {
+
+                if (start <= range[j].start && end >= range[j].end) {
                         range[j].start = 0;
                         range[j].end = 0;
-                        break;
-                } else if (start > range[j].start && end == range[j].end) {
+                        continue;
+                }
+
+                if (start <= range[j].start && end < range[j].end && range[j].start < end + 1) {
+                        range[j].start = end + 1;
+                        continue;
+                }
+
+
+                if (start > range[j].start && end >= range[j].end && range[j].end > start - 1) {
                         range[j].end = start - 1;
-                        break;
-                } else if (start > range[j].start && end < range[j].end) {
+                        continue;
+                }
+
+                if (start > range[j].start && end < range[j].end) {
                         /* find the new spare */
                         for (i = 0; i < RANGE_NUM; i++) {
                                 if (range[i].end == 0)
@@ -135,7 +143,7 @@ static void __init update_range(struct res_range *range, size_t start,
                                 printk(KERN_ERR "run of slot in ranges\n");
                         }
                         range[j].end = start - 1;
-                        break;
+                        continue;
                 }
         }
 }
@@ -151,16 +159,24 @@ static void __init update_res(struct pci_root_info *info, size_t start,
 
         /* try to merge it with old one */
         for (i = 0; i < info->res_num; i++) {
+                size_t final_start, final_end;
+                size_t common_start, common_end;
+
                 res = &info->res[i];
                 if (res->flags != flags)
                         continue;
-                if (res->end + 1 == start) {
-                        res->end = end;
-                        return;
-                } else if (end + 1 == res->start) {
-                        res->start = start;
-                        return;
-                }
+
+                common_start = max((size_t)res->start, start);
+                common_end = min((size_t)res->end, end);
+                if (common_start > common_end + 1)
+                        continue;
+
+                final_start = min((size_t)res->start, start);
+                final_end = max((size_t)res->end, end);
+
+                res->start = final_start;
+                res->end = final_end;
+                return;
         }
 
 addit:
@@ -336,7 +352,11 @@ static int __init early_fill_mp_bus_info(void)
                 info = &pci_root_info[j];
                 printk(KERN_DEBUG "node %d link %d: io port [%llx, %llx]\n",
                        node, link, (u64)start, (u64)end);
-                update_res(info, start, end, IORESOURCE_IO, 0);
+
+                /* kernel only handle 16 bit only */
+                if (end > 0xffff)
+                        end = 0xffff;
+                update_res(info, start, end, IORESOURCE_IO, 1);
                 update_range(range, start, end);
         }
         /* add left over io port range to def node/link, [0, 0xffff] */
@@ -444,7 +464,7 @@ static int __init early_fill_mp_bus_info(void)
                         }
                 }
 
-                update_res(info, start, end, IORESOURCE_MEM, 0);
+                update_res(info, start, end, IORESOURCE_MEM, 1);
                 update_range(range, start, end);
                 printk(KERN_CONT "\n");
         }