From ea8a218e87fb4b26ce48717f9051df6d8fe32ab2 Mon Sep 17 00:00:00 2001
From: FUJITA Tomonori <tomof@acm.org>
Date: Mon, 4 Feb 2008 22:28:07 -0800
Subject: [PATCH] --- yaml --- r: 83019 b: refs/heads/master c:
 0291df8cc9dac09c303d21d5bcd2ad73762c836a h: refs/heads/master i:   83017:
 7f482aa5d1882deb4d886d1886c49babdc4126ff   83015:
 28f6b511457481a2132b27351730baa1367884c0 v: v3

---
 [refs]                             |  2 +-
 trunk/include/linux/iommu-helper.h |  7 +++
 trunk/lib/Makefile                 |  1 +
 trunk/lib/iommu-helper.c           | 80 ++++++++++++++++++++++++++++++
 4 files changed, 89 insertions(+), 1 deletion(-)
 create mode 100644 trunk/include/linux/iommu-helper.h
 create mode 100644 trunk/lib/iommu-helper.c

diff --git a/[refs] b/[refs]
index e22a0fb5fc0a..f035bd3a5bff 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 0c95fdc59640824d7e0b017be295fb912ceef4ab
+refs/heads/master: 0291df8cc9dac09c303d21d5bcd2ad73762c836a
diff --git a/trunk/include/linux/iommu-helper.h b/trunk/include/linux/iommu-helper.h
new file mode 100644
index 000000000000..4dd4c04ff2f4
--- /dev/null
+++ b/trunk/include/linux/iommu-helper.h
@@ -0,0 +1,7 @@
+extern unsigned long iommu_area_alloc(unsigned long *map, unsigned long size,
+				      unsigned long start, unsigned int nr,
+				      unsigned long shift,
+				      unsigned long boundary_size,
+				      unsigned long align_mask);
+extern void iommu_area_free(unsigned long *map, unsigned long start,
+			    unsigned int nr);
diff --git a/trunk/lib/Makefile b/trunk/lib/Makefile
index 543f2502b60a..a18062e4633f 100644
--- a/trunk/lib/Makefile
+++ b/trunk/lib/Makefile
@@ -65,6 +65,7 @@ obj-$(CONFIG_SMP) += pcounter.o
 obj-$(CONFIG_AUDIT_GENERIC) += audit.o
 
 obj-$(CONFIG_SWIOTLB) += swiotlb.o
+obj-$(CONFIG_IOMMU_HELPER) += iommu-helper.o
 obj-$(CONFIG_FAULT_INJECTION) += fault-inject.o
 
 lib-$(CONFIG_GENERIC_BUG) += bug.o
diff --git a/trunk/lib/iommu-helper.c b/trunk/lib/iommu-helper.c
new file mode 100644
index 000000000000..495575a59ca6
--- /dev/null
+++ b/trunk/lib/iommu-helper.c
@@ -0,0 +1,80 @@
+/*
+ * IOMMU helper functions for the free area management
+ */
+
+#include <linux/module.h>
+#include <linux/bitops.h>
+
+static unsigned long find_next_zero_area(unsigned long *map,
+					 unsigned long size,
+					 unsigned long start,
+					 unsigned int nr,
+					 unsigned long align_mask)
+{
+	unsigned long index, end, i;
+again:
+	index = find_next_zero_bit(map, size, start);
+
+	/* Align allocation */
+	index = (index + align_mask) & ~align_mask;
+
+	end = index + nr;
+	if (end >= size)
+		return -1;
+	for (i = index; i < end; i++) {
+		if (test_bit(i, map)) {
+			start = i+1;
+			goto again;
+		}
+	}
+	return index;
+}
+
+static inline void set_bit_area(unsigned long *map, unsigned long i,
+				int len)
+{
+	unsigned long end = i + len;
+	while (i < end) {
+		__set_bit(i, map);
+		i++;
+	}
+}
+
+static inline int is_span_boundary(unsigned int index, unsigned int nr,
+				   unsigned long shift,
+				   unsigned long boundary_size)
+{
+	shift = (shift + index) & (boundary_size - 1);
+	return shift + nr > boundary_size;
+}
+
+unsigned long iommu_area_alloc(unsigned long *map, unsigned long size,
+			       unsigned long start, unsigned int nr,
+			       unsigned long shift, unsigned long boundary_size,
+			       unsigned long align_mask)
+{
+	unsigned long index;
+again:
+	index = find_next_zero_area(map, size, start, nr, align_mask);
+	if (index != -1) {
+		if (is_span_boundary(index, nr, shift, boundary_size)) {
+			/* we could do more effectively */
+			start = index + 1;
+			goto again;
+		}
+		set_bit_area(map, index, nr);
+	}
+	return index;
+}
+EXPORT_SYMBOL(iommu_area_alloc);
+
+void iommu_area_free(unsigned long *map, unsigned long start, unsigned int nr)
+{
+	unsigned long end = start + nr;
+
+	while (start < end) {
+		__clear_bit(start, map);
+		start++;
+	}
+}
+EXPORT_SYMBOL(iommu_area_free);