[PATCH v3 5/8] acpi/gpex: Append pxb devs in ascending order

[Jiahui Cen]

The overlap check of IO resource window would fail when Linux kernel
registers an IO resource [b, c) earlier than another resource [a, b).
Though this incorrect check could be fixed by [1], it would be better to
append pxb devs into DSDT table in ascending order.

[1]: https://lore.kernel.org/lkml/20201218062335.5320-1-cenjiahui@huawei.com/

Signed-off-by: Jiahui Cen <cenjiahui@huawei.com>
---
 hw/pci-host/gpex-acpi.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/hw/pci-host/gpex-acpi.c b/hw/pci-host/gpex-acpi.c
index 4bf1e94309..95a7a0f12b 100644
--- a/hw/pci-host/gpex-acpi.c
+++ b/hw/pci-host/gpex-acpi.c
@@ -141,7 +141,7 @@ static void acpi_dsdt_add_pci_osc(Aml *dev)
 void acpi_dsdt_add_gpex(Aml *scope, struct GPEXConfig *cfg)
 {
     int nr_pcie_buses = cfg->ecam.size / PCIE_MMCFG_SIZE_MIN;
-    Aml *method, *crs, *dev, *rbuf;
+    Aml *method, *crs, *dev, *rbuf, *pxb_devs[nr_pcie_buses];
     PCIBus *bus = cfg->bus;
     CrsRangeSet crs_range_set;
     CrsRangeEntry *entry;
@@ -149,6 +149,7 @@ void acpi_dsdt_add_gpex(Aml *scope, struct GPEXConfig *cfg)
 
     /* start to construct the tables for pxb */
     crs_range_set_init(&crs_range_set);
+    memset(pxb_devs, 0, sizeof(pxb_devs));
     if (bus) {
         QLIST_FOREACH(bus, &bus->child, sibling) {
             uint8_t bus_num = pci_bus_num(bus);
@@ -190,7 +191,7 @@ void acpi_dsdt_add_gpex(Aml *scope, struct GPEXConfig *cfg)
 
             acpi_dsdt_add_pci_osc(dev);
 
-            aml_append(scope, dev);
+            pxb_devs[bus_num] = dev;
         }
     }
 
@@ -278,5 +279,11 @@ void acpi_dsdt_add_gpex(Aml *scope, struct GPEXConfig *cfg)
     aml_append(dev, dev_res0);
     aml_append(scope, dev);
 
+    for (i = 0; i < ARRAY_SIZE(pxb_devs); i++) {
+        if (pxb_devs[i]) {
+            aml_append(scope, pxb_devs[i]);
+        }
+    }
+
     crs_range_set_free(&crs_range_set);
 }
-- 
2.29.2