[PATCH v2 for-4.20? 6/6] PCI: drop pci_segments_init()

[Jan Beulich <jbeulich@xxxxxxxx>]

Have callers invoke pci_add_segment() directly instead. On x86 move the
invocation back to acpi_mmcfg_init(), where it was prior to ????????????
("x86/PCI: init segments earlier").
---
v2: New.

--- a/xen/arch/arm/pci/pci.c
+++ b/xen/arch/arm/pci/pci.c
@@ -88,7 +88,8 @@ static int __init pci_init(void)
     if ( !pci_passthrough_enabled )
         return 0;
 
-    pci_segments_init();
+    if ( pci_add_segment(0) )
+        panic("Could not initialize PCI segment 0\n");
 
     if ( acpi_disabled )
         return dt_pci_init();
--- a/xen/arch/x86/x86_64/mmconfig-shared.c
+++ b/xen/arch/x86/x86_64/mmconfig-shared.c
@@ -402,6 +402,9 @@ void __init acpi_mmcfg_init(void)
 {
     bool valid = true;
 
+    if ( pci_add_segment(0) )
+        panic("Could not initialize PCI segment 0\n");
+
     /* MMCONFIG disabled */
     if ((pci_probe & PCI_PROBE_MMCONF) == 0)
         return;
--- a/xen/drivers/passthrough/pci.c
+++ b/xen/drivers/passthrough/pci.c
@@ -122,12 +122,6 @@ static int pci_segments_iterate(
     return rc;
 }
 
-void __init pci_segments_init(void)
-{
-    if ( !alloc_pseg(0) )
-        panic("Could not initialize PCI segment 0\n");
-}
-
 int __init pci_add_segment(u16 seg)
 {
     return alloc_pseg(seg) ? 0 : -ENOMEM;
--- a/xen/drivers/passthrough/x86/iommu.c
+++ b/xen/drivers/passthrough/x86/iommu.c
@@ -55,8 +55,6 @@ void __init acpi_iommu_init(void)
 {
     int ret = -ENODEV;
 
-    pci_segments_init();
-
     if ( !iommu_enable && !iommu_intremap )
         return;
 
--- a/xen/include/xen/pci.h
+++ b/xen/include/xen/pci.h
@@ -214,7 +214,6 @@ void setup_hwdom_pci_devices(struct doma
                              int (*handler)(uint8_t devfn,
                                             struct pci_dev *pdev));
 int pci_release_devices(struct domain *d);
-void pci_segments_init(void);
 int pci_add_segment(u16 seg);
 const unsigned long *pci_get_ro_map(u16 seg);
 int pci_add_device(u16 seg, u8 bus, u8 devfn,