+// helper functions to manage pci io/memory/prefetch memory region
+//
+// Copyright (C) 2009 Isaku Yamahata <yamahata at valinux co jp>
+//
+// This file may be distributed under the terms of the GNU LGPLv3 license.
+//
+//
+
+#include "util.h"
+
+#define PCI_REGION_DISABLED (-1)
+
+void pci_region_init(struct pci_region *r, u32 first, u32 last)
+{
+ r->first = first;
+ r->last = last;
+
+ r->cur_first = r->first;
+}
+
+// PCI_REGION_DISABLED represents that the region is in special state.
+// its value is chosen such that cur_first can't be PCI_REGION_DISABLED
+// normally.
+// NOTE: the area right below 4G is used for LAPIC, so such area can't
+// be used for PCI memory.
+u32 pci_region_disable(struct pci_region *r)
+{
+ return r->cur_first = PCI_REGION_DISABLED;
+}
+
+static int pci_region_disabled(const struct pci_region *r)
+{
+ return r->cur_first == PCI_REGION_DISABLED;
+}
+
+static u32 pci_region_alloc_align(struct pci_region *r, u32 size, u32 align)
+{
+ if (pci_region_disabled(r)) {
+ return 0;
+ }
+
+ u32 s = ALIGN(r->cur_first, align);
+ if (s > r->last || s < r->cur_first) {
+ return 0;
+ }
+ u32 e = s + size;
+ if (e < s || e - 1 > r->last) {
+ return 0;
+ }
+ r->cur_first = e;
+ return s;
+}
+
+u32 pci_region_alloc(struct pci_region *r, u32 size)
+{
+ return pci_region_alloc_align(r, size, size);
+}
+
+u32 pci_region_align(struct pci_region *r, u32 align)
+{
+ return pci_region_alloc_align(r, 0, align);
+}
+
+void pci_region_revert(struct pci_region *r, u32 addr)
+{
+ r->cur_first = addr;
+}
+
+u32 pci_region_addr(const struct pci_region *r)
+{
+ return r->cur_first;
+}
+
+u32 pci_region_size(const struct pci_region *r)
+{
+ return r->last - r->first + 1;
+}