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>

diff --git a/arch/x86/pci/k8-bus_64.c b/arch/x86/pci/k8-bus_64.c
index 4e64c58..ab6d4b1 100644 (file)
--- 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");
        }