[Qemu-devel] [PATCH v2 1/2] pci: introduce pci_region to manage pci io/memory/prefmemory regions.

[Isaku Yamahata]

This patch adds helper functions to manage pci area.

Signed-off-by: Isaku Yamahata <address@hidden>

---
Changes v1 -> v2
- add comments
---
 Makefile         |    3 +-
 src/pci_region.c |   77 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 src/util.h       |   28 +++++++++++++++++++
 3 files changed, 107 insertions(+), 1 deletions(-)
 create mode 100644 src/pci_region.c

diff --git a/Makefile b/Makefile
index 9d412f1..1663a5d 100644
--- a/Makefile
+++ b/Makefile
@@ -19,7 +19,8 @@ SRCBOTH=misc.c pmm.c stacks.c output.c util.c block.c 
floppy.c ata.c mouse.c \
 SRC16=$(SRCBOTH) system.c disk.c font.c
 SRC32FLAT=$(SRCBOTH) post.c shadow.c memmap.c coreboot.c boot.c \
       acpi.c smm.c mptable.c smbios.c pciinit.c optionroms.c mtrr.c \
-      lzmadecode.c bootsplash.c jpeg.c usb-hub.c paravirt.c dev-i440fx.c
+      lzmadecode.c bootsplash.c jpeg.c usb-hub.c paravirt.c dev-i440fx.c \
+      pci_region.c
 SRC32SEG=util.c output.c pci.c pcibios.c apm.c stacks.c
 
 cc-option = $(shell if test -z "`$(1) $(2) -S -o /dev/null -xc \
diff --git a/src/pci_region.c b/src/pci_region.c
new file mode 100644
index 0000000..c8656cb
--- /dev/null
+++ b/src/pci_region.c
@@ -0,0 +1,77 @@
+// 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 start, u32 end)
+{
+    r->start = start;
+    r->end = end;
+
+    r->cur_end = start;
+}
+
+// PCI_REGION_DISABLED represents that the region is in special state.
+// its value is chosen such that cur_end can't be PCI_REGION_DISABLED normally.
+u32 pci_region_disable(struct pci_region *r)
+{
+    return r->cur_end = PCI_REGION_DISABLED;
+}
+
+static int pci_region_disabled(const struct pci_region *r)
+{
+    return r->cur_end == 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_end, align);
+    if (s > r->end || s < r->cur_end) {
+        return 0;
+    }
+    u32 e = s + size;
+    if (e > r->end || e < s) {
+        return 0;
+    }
+    r->cur_end = 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_end = addr;
+}
+
+u32 pci_region_addr(const struct pci_region *r)
+{
+    if (pci_region_disabled(r)){
+        return r->end;
+    }
+    return r->cur_end;
+}
+
+u32 pci_region_size(const struct pci_region *r)
+{
+    return r->end - r->start;
+}
diff --git a/src/util.h b/src/util.h
index 5cc9f17..17eedd0 100644
--- a/src/util.h
+++ b/src/util.h
@@ -344,6 +344,34 @@ void qemu_prep_reset(void);
 void smm_save_and_copy(void);
 void smm_relocate_and_restore(void);
 
+// pci_region.c
+// region allocator. pci region allocates the requested region
+// sequentially with overflow check.
+struct pci_region {
+    // The region is [start, region).
+    u32 start;
+    u32 end;
+
+    // The next allocation is start from this.
+    // i.e. [start, cur_end) is allocated.
+    // Right after initialization cur_end == start.
+    u32 cur_end;
+};
+// initialize the pci_region of [start, end)
+void pci_region_init(struct pci_region *r, u32 start, u32 end);
+// allocate the region of size
+u32 pci_region_alloc(struct pci_region *r, u32 size);
+// make the next allocation aligned to align
+u32 pci_region_align(struct pci_region *r, u32 align);
+// revert the allocation to addr.
+void pci_region_revert(struct pci_region *r, u32 addr);
+// make the allocation fail.
+u32 pci_region_disable(struct pci_region *r);
+// returns the current allocation point.
+u32 pci_region_addr(const struct pci_region *r);
+// returns the region size.
+u32 pci_region_size(const struct pci_region *r);
+
 // pciinit.c
 extern const u8 pci_irqs[4];
 void pci_bios_allocate_regions(u16 bdf, void *arg);
-- 
1.7.1.1