[PATCH 1/7] bitmap: Introduce bitmap_set, bitmap_clear, bitmap_find_next_zero_area

[PATCH 1/7] bitmap: Introduce bitmap_set, bitmap_clear, bitmap_find_next_zero_area

[Akinobu Mita]

This introduces new bitmap functions:

bitmap_set: Set specified bit area
bitmap_clear: Clear specified bit area
bitmap_find_next_zero_area: Find free bit area

These are mostly stolen from iommu helper. The differences are:

- Use find_next_bit instead of doing test_bit for each bit

- Rewrite bitmap_set and bitmap_clear

  Instead of setting or clearing for each bit.

- Check the last bit of the limit

  iommu-helper doesn't want to find such area

- The return value if there is no zero area

  find_next_zero_area in iommu helper: returns -1
  bitmap_find_next_zero_area: return >= bitmap size

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: sparclinux@vger.kernel.org
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: linuxppc-dev@ozlabs.org
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Lothar Wassmann <LW@KARO-electronics.de>
Cc: linux-usb@vger.kernel.org
Cc: Roland Dreier <rolandd@cisco.com>
Cc: Yevgeny Petrilin <yevgenyp@mellanox.co.il>
Cc: netdev@vger.kernel.org
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: linux-ia64@vger.kernel.org
Cc: linux-altix@sgi.com
Cc: Joerg Roedel <joerg.roedel@amd.com>
---
 include/linux/bitmap.h |   11 ++++++
 lib/bitmap.c           |   81 ++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 92 insertions(+), 0 deletions(-)

diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h
index 756d78b..daf8c48 100644
--- a/include/linux/bitmap.h
+++ b/include/linux/bitmap.h
@@ -42,6 +42,9 @@
  * bitmap_empty(src, nbits)			Are all bits zero in *src?
  * bitmap_full(src, nbits)			Are all bits set in *src?
  * bitmap_weight(src, nbits)			Hamming Weight: number set bits
+ * bitmap_set(dst, pos, nbits)			Set specified bit area
+ * bitmap_clear(dst, pos, nbits)		Clear specified bit area
+ * bitmap_find_next_zero_area(buf, len, pos, n, mask)	Find bit free area
  * bitmap_shift_right(dst, src, n, nbits)	*dst = *src >> n
  * bitmap_shift_left(dst, src, n, nbits)	*dst = *src << n
  * bitmap_remap(dst, src, old, new, nbits)	*dst = map(old, new)(src)
@@ -108,6 +111,14 @@ extern int __bitmap_subset(const unsigned long *bitmap1,
 			const unsigned long *bitmap2, int bits);
 extern int __bitmap_weight(const unsigned long *bitmap, int bits);
 
+extern void bitmap_set(unsigned long *map, int i, int len);
+extern void bitmap_clear(unsigned long *map, int start, int nr);
+extern unsigned long bitmap_find_next_zero_area(unsigned long *map,
+					 unsigned long size,
+					 unsigned long start,
+					 unsigned int nr,
+					 unsigned long align_mask);
+
 extern int bitmap_scnprintf(char *buf, unsigned int len,
 			const unsigned long *src, int nbits);
 extern int __bitmap_parse(const char *buf, unsigned int buflen, int is_user,
diff --git a/lib/bitmap.c b/lib/bitmap.c
index 7025658..11bf497 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -271,6 +271,87 @@ int __bitmap_weight(const unsigned long *bitmap, int bits)
 }
 EXPORT_SYMBOL(__bitmap_weight);
 
+#define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) % BITS_PER_LONG))
+
+void bitmap_set(unsigned long *map, int start, int nr)
+{
+	unsigned long *p = map + BIT_WORD(start);
+	const int size = start + nr;
+	int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG);
+	unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start);
+
+	while (nr - bits_to_set >= 0) {
+		*p |= mask_to_set;
+		nr -= bits_to_set;
+		bits_to_set = BITS_PER_LONG;
+		mask_to_set = ~0UL;
+		p++;
+	}
+	if (nr) {
+		mask_to_set &= BITMAP_LAST_WORD_MASK(size);
+		*p |= mask_to_set;
+	}
+}
+EXPORT_SYMBOL(bitmap_set);
+
+void bitmap_clear(unsigned long *map, int start, int nr)
+{
+	unsigned long *p = map + BIT_WORD(start);
+	const int size = start + nr;
+	int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG);
+	unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start);
+
+	while (nr - bits_to_clear >= 0) {
+		*p &= ~mask_to_clear;
+		nr -= bits_to_clear;
+		bits_to_clear = BITS_PER_LONG;
+		mask_to_clear = ~0UL;
+		p++;
+	}
+	if (nr) {
+		mask_to_clear &= BITMAP_LAST_WORD_MASK(size);
+		*p &= ~mask_to_clear;
+	}
+}
+EXPORT_SYMBOL(bitmap_clear);
+
+/*
+ * bitmap_find_next_zero_area - find a contiguous aligned zero area
+ * @map: The address to base the search on
+ * @size: The bitmap size in bits
+ * @start: The bitnumber to start searching at
+ * @nr: The number of zeroed bits we're looking for
+ * @align_mask: Alignment mask for zero area
+ *
+ * The @align_mask should be one less than a power of 2; the effect is that
+ * the bit offset of all zero areas this function finds is multiples of that
+ * power of 2. A @align_mask of 0 means no alignment is required.
+ */
+unsigned long bitmap_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 = __ALIGN_MASK(index, align_mask);
+
+	end = index + nr;
+	if (end > size)
+		return end;
+	i = find_next_bit(map, end, index);
+	if (i < end) {
+		start = i + 1;
+		goto again;
+	}
+	return index;
+}
+EXPORT_SYMBOL(bitmap_find_next_zero_area);
+
 /*
  * Bitmap printing & parsing functions: first version by Bill Irwin,
  * second version by Paul Jackson, third by Joe Korty.
-- 
1.6.5.1

[PATCH 2/7] iommu-helper: Use bitmap library

[Akinobu Mita]

Use bitmap library and kill some unused iommu helper functions.

1. s/iommu_area_free/bitmap_clear/

2. s/iommu_area_reserve/bitmap_set/

3. Use bitmap_find_next_zero_area instead of find_next_zero_area

  This cannot be simple substitution because find_next_zero_area
  doesn't check the last bit of the limit in bitmap

4. Remove iommu_area_free, iommu_area_reserve, and find_next_zero_area

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: sparclinux@vger.kernel.org
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: linuxppc-dev@ozlabs.org
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Joerg Roedel <joerg.roedel@amd.com>
---
 arch/powerpc/kernel/iommu.c      |    4 +-
 arch/sparc/kernel/iommu.c        |    3 +-
 arch/x86/kernel/amd_iommu.c      |    4 +-
 arch/x86/kernel/pci-calgary_64.c |    6 ++--
 arch/x86/kernel/pci-gart_64.c    |    6 ++--
 include/linux/iommu-helper.h     |    3 --
 lib/iommu-helper.c               |   59 ++++++--------------------------------
 7 files changed, 21 insertions(+), 64 deletions(-)

diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
index fd51578..5547ae6 100644
--- a/arch/powerpc/kernel/iommu.c
+++ b/arch/powerpc/kernel/iommu.c
@@ -30,7 +30,7 @@
 #include <linux/spinlock.h>
 #include <linux/string.h>
 #include <linux/dma-mapping.h>
-#include <linux/bitops.h>
+#include <linux/bitmap.h>
 #include <linux/iommu-helper.h>
 #include <linux/crash_dump.h>
 #include <asm/io.h>
@@ -251,7 +251,7 @@ static void __iommu_free(struct iommu_table *tbl, dma_addr_t dma_addr,
 	}
 
 	ppc_md.tce_free(tbl, entry, npages);
-	iommu_area_free(tbl->it_map, free_entry, npages);
+	bitmap_clear(tbl->it_map, free_entry, npages);
 }
 
 static void iommu_free(struct iommu_table *tbl, dma_addr_t dma_addr,
diff --git a/arch/sparc/kernel/iommu.c b/arch/sparc/kernel/iommu.c
index 7690cc2..5fad949 100644
--- a/arch/sparc/kernel/iommu.c
+++ b/arch/sparc/kernel/iommu.c
@@ -11,6 +11,7 @@
 #include <linux/dma-mapping.h>
 #include <linux/errno.h>
 #include <linux/iommu-helper.h>
+#include <linux/bitmap.h>
 
 #ifdef CONFIG_PCI
 #include <linux/pci.h>
@@ -169,7 +170,7 @@ void iommu_range_free(struct iommu *iommu, dma_addr_t dma_addr, unsigned long np
 
 	entry = (dma_addr - iommu->page_table_map_base) >> IO_PAGE_SHIFT;
 
-	iommu_area_free(arena->map, entry, npages);
+	bitmap_clear(arena->map, entry, npages);
 }
 
 int iommu_table_init(struct iommu *iommu, int tsbsize,
diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c
index 98f230f..08b1d20 100644
--- a/arch/x86/kernel/amd_iommu.c
+++ b/arch/x86/kernel/amd_iommu.c
@@ -19,7 +19,7 @@
 
 #include <linux/pci.h>
 #include <linux/gfp.h>
-#include <linux/bitops.h>
+#include <linux/bitmap.h>
 #include <linux/debugfs.h>
 #include <linux/scatterlist.h>
 #include <linux/dma-mapping.h>
@@ -959,7 +959,7 @@ static void dma_ops_free_addresses(struct dma_ops_domain *dom,
 
 	address = (address % APERTURE_RANGE_SIZE) >> PAGE_SHIFT;
 
-	iommu_area_free(range->bitmap, address, pages);
+	bitmap_clear(range->bitmap, address, pages);
 
 }
 
diff --git a/arch/x86/kernel/pci-calgary_64.c b/arch/x86/kernel/pci-calgary_64.c
index 971a3be..c87bb20 100644
--- a/arch/x86/kernel/pci-calgary_64.c
+++ b/arch/x86/kernel/pci-calgary_64.c
@@ -31,7 +31,7 @@
 #include <linux/string.h>
 #include <linux/crash_dump.h>
 #include <linux/dma-mapping.h>
-#include <linux/bitops.h>
+#include <linux/bitmap.h>
 #include <linux/pci_ids.h>
 #include <linux/pci.h>
 #include <linux/delay.h>
@@ -211,7 +211,7 @@ static void iommu_range_reserve(struct iommu_table *tbl,
 
 	spin_lock_irqsave(&tbl->it_lock, flags);
 
-	iommu_area_reserve(tbl->it_map, index, npages);
+	bitmap_set(tbl->it_map, index, npages);
 
 	spin_unlock_irqrestore(&tbl->it_lock, flags);
 }
@@ -305,7 +305,7 @@ static void iommu_free(struct iommu_table *tbl, dma_addr_t dma_addr,
 
 	spin_lock_irqsave(&tbl->it_lock, flags);
 
-	iommu_area_free(tbl->it_map, entry, npages);
+	bitmap_clear(tbl->it_map, entry, npages);
 
 	spin_unlock_irqrestore(&tbl->it_lock, flags);
 }
diff --git a/arch/x86/kernel/pci-gart_64.c b/arch/x86/kernel/pci-gart_64.c
index a7f1b64..156e362 100644
--- a/arch/x86/kernel/pci-gart_64.c
+++ b/arch/x86/kernel/pci-gart_64.c
@@ -23,7 +23,7 @@
 #include <linux/module.h>
 #include <linux/topology.h>
 #include <linux/interrupt.h>
-#include <linux/bitops.h>
+#include <linux/bitmap.h>
 #include <linux/kdebug.h>
 #include <linux/scatterlist.h>
 #include <linux/iommu-helper.h>
@@ -123,7 +123,7 @@ static void free_iommu(unsigned long offset, int size)
 	unsigned long flags;
 
 	spin_lock_irqsave(&iommu_bitmap_lock, flags);
-	iommu_area_free(iommu_gart_bitmap, offset, size);
+	bitmap_clear(iommu_gart_bitmap, offset, size);
 	if (offset >= next_bit)
 		next_bit = offset + size;
 	spin_unlock_irqrestore(&iommu_bitmap_lock, flags);
@@ -782,7 +782,7 @@ void __init gart_iommu_init(void)
 	 * Out of IOMMU space handling.
 	 * Reserve some invalid pages at the beginning of the GART.
 	 */
-	iommu_area_reserve(iommu_gart_bitmap, 0, EMERGENCY_PAGES);
+	bitmap_set(iommu_gart_bitmap, 0, EMERGENCY_PAGES);
 
 	agp_memory_reserved = iommu_size;
 	printk(KERN_INFO
diff --git a/include/linux/iommu-helper.h b/include/linux/iommu-helper.h
index 3b068e5..64d1b63 100644
--- a/include/linux/iommu-helper.h
+++ b/include/linux/iommu-helper.h
@@ -14,14 +14,11 @@ static inline unsigned long iommu_device_max_index(unsigned long size,
 extern int iommu_is_span_boundary(unsigned int index, unsigned int nr,
 				  unsigned long shift,
 				  unsigned long boundary_size);
-extern void iommu_area_reserve(unsigned long *map, unsigned long i, int len);
 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);
 
 extern unsigned long iommu_num_pages(unsigned long addr, unsigned long len,
 				     unsigned long io_page_size);
diff --git a/lib/iommu-helper.c b/lib/iommu-helper.c
index 75dbda0..c0251f4 100644
--- a/lib/iommu-helper.c
+++ b/lib/iommu-helper.c
@@ -3,41 +3,7 @@
  */
 
 #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;
-}
-
-void iommu_area_reserve(unsigned long *map, unsigned long i, int len)
-{
-	unsigned long end = i + len;
-	while (i < end) {
-		__set_bit(i, map);
-		i++;
-	}
-}
+#include <linux/bitmap.h>
 
 int iommu_is_span_boundary(unsigned int index, unsigned int nr,
 			   unsigned long shift,
@@ -55,31 +21,24 @@ unsigned long iommu_area_alloc(unsigned long *map, unsigned long size,
 			       unsigned long align_mask)
 {
 	unsigned long index;
+
+	/* We don't want the last of the limit */
+	size -= 1;
 again:
-	index = find_next_zero_area(map, size, start, nr, align_mask);
-	if (index != -1) {
+	index = bitmap_find_next_zero_area(map, size, start, nr, align_mask);
+	if (index < size) {
 		if (iommu_is_span_boundary(index, nr, shift, boundary_size)) {
 			/* we could do more effectively */
 			start = index + 1;
 			goto again;
 		}
-		iommu_area_reserve(map, index, nr);
+		bitmap_set(map, index, nr);
+		return index;
 	}
-	return index;
+	return -1;
 }
 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);
-
 unsigned long iommu_num_pages(unsigned long addr, unsigned long len,
 			      unsigned long io_page_size)
 {
-- 
1.6.5.1

[PATCH 3/7] isp1362-hcd: Use bitmap_find_next_zero_area

[Akinobu Mita]

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Lothar Wassmann <LW@KARO-electronics.de>
Cc: linux-usb@vger.kernel.org
---
 drivers/usb/host/isp1362-hcd.c |   26 ++++++--------------------
 1 files changed, 6 insertions(+), 20 deletions(-)

diff --git a/drivers/usb/host/isp1362-hcd.c b/drivers/usb/host/isp1362-hcd.c
index 5c774ab..73352f3 100644
--- a/drivers/usb/host/isp1362-hcd.c
+++ b/drivers/usb/host/isp1362-hcd.c
@@ -80,7 +80,7 @@
 #include <linux/platform_device.h>
 #include <linux/pm.h>
 #include <linux/io.h>
-#include <linux/bitops.h>
+#include <linux/bitmap.h>
 
 #include <asm/irq.h>
 #include <asm/system.h>
@@ -190,10 +190,8 @@ static int claim_ptd_buffers(struct isp1362_ep_queue *epq,
 			     struct isp1362_ep *ep, u16 len)
 {
 	int ptd_offset = -EINVAL;
-	int index;
 	int num_ptds = ((len + PTD_HEADER_SIZE - 1) / epq->blk_size) + 1;
-	int found = -1;
-	int last = -1;
+	int found;
 
 	BUG_ON(len > epq->buf_size);
 
@@ -205,20 +203,9 @@ static int claim_ptd_buffers(struct isp1362_ep_queue *epq,
 		    epq->name, len, epq->blk_size, num_ptds, epq->buf_map, epq->skip_map);
 	BUG_ON(ep->num_ptds != 0);
 
-	for (index = 0; index <= epq->buf_count - num_ptds; index++) {
-		if (test_bit(index, &epq->buf_map))
-			continue;
-		found = index;
-		for (last = index + 1; last < index + num_ptds; last++) {
-			if (test_bit(last, &epq->buf_map)) {
-				found = -1;
-				break;
-			}
-		}
-		if (found >= 0)
-			break;
-	}
-	if (found < 0)
+	found = bitmap_find_next_zero_area(&epq->buf_map, epq->buf_count, 0,
+						num_ptds, 0);
+	if (found >= epq->buf_count)
 		return -EOVERFLOW;
 
 	DBG(1, "%s: Found %d PTDs[%d] for %d/%d byte\n", __func__,
@@ -230,8 +217,7 @@ static int claim_ptd_buffers(struct isp1362_ep_queue *epq,
 	epq->buf_avail -= num_ptds;
 	BUG_ON(epq->buf_avail > epq->buf_count);
 	ep->ptd_index = found;
-	for (index = found; index < last; index++)
-		__set_bit(index, &epq->buf_map);
+	bitmap_set(&epq->buf_map, found, num_ptds);
 	DBG(1, "%s: Done %s PTD[%d] $%04x, avail %d count %d claimed %d %08lx:%08lx\n",
 	    __func__, epq->name, ep->ptd_index, ep->ptd_offset,
 	    epq->buf_avail, epq->buf_count, num_ptds, epq->buf_map, epq->skip_map);
-- 
1.6.5.1

[PATCH 4/7] mlx4: Use bitmap_find_next_zero_area

[Akinobu Mita]

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: Roland Dreier <rolandd@cisco.com>
Cc: Yevgeny Petrilin <yevgenyp@mellanox.co.il>
Cc: netdev@vger.kernel.org
---
 drivers/net/mlx4/alloc.c |   37 ++++---------------------------------
 1 files changed, 4 insertions(+), 33 deletions(-)

diff --git a/drivers/net/mlx4/alloc.c b/drivers/net/mlx4/alloc.c
index ad95d5f..8c85156 100644
--- a/drivers/net/mlx4/alloc.c
+++ b/drivers/net/mlx4/alloc.c
@@ -72,35 +72,6 @@ void mlx4_bitmap_free(struct mlx4_bitmap *bitmap, u32 obj)
 	mlx4_bitmap_free_range(bitmap, obj, 1);
 }
 
-static unsigned long find_aligned_range(unsigned long *bitmap,
-					u32 start, u32 nbits,
-					int len, int align)
-{
-	unsigned long end, i;
-
-again:
-	start = ALIGN(start, align);
-
-	while ((start < nbits) && test_bit(start, bitmap))
-		start += align;
-
-	if (start >= nbits)
-		return -1;
-
-	end = start+len;
-	if (end > nbits)
-		return -1;
-
-	for (i = start + 1; i < end; i++) {
-		if (test_bit(i, bitmap)) {
-			start = i + 1;
-			goto again;
-		}
-	}
-
-	return start;
-}
-
 u32 mlx4_bitmap_alloc_range(struct mlx4_bitmap *bitmap, int cnt, int align)
 {
 	u32 obj, i;
@@ -110,13 +81,13 @@ u32 mlx4_bitmap_alloc_range(struct mlx4_bitmap *bitmap, int cnt, int align)
 
 	spin_lock(&bitmap->lock);
 
-	obj = find_aligned_range(bitmap->table, bitmap->last,
-				 bitmap->max, cnt, align);
+	obj = bitmap_find_next_zero_area(bitmap->table, bitmap->max,
+				bitmap->last, cnt, align - 1);
 	if (obj >= bitmap->max) {
 		bitmap->top = (bitmap->top + bitmap->max + bitmap->reserved_top)
 				& bitmap->mask;
-		obj = find_aligned_range(bitmap->table, 0, bitmap->max,
-					 cnt, align);
+		obj = bitmap_find_next_zero_area(bitmap->table, bitmap->max,
+						0, cnt, align - 1);
 	}
 
 	if (obj < bitmap->max) {
-- 
1.6.5.1

[PATCH 5/7] sparc: Use bitmap_find_next_zero_area

[Akinobu Mita]

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Acked-by: "David S. Miller" <davem@davemloft.net>
Cc: sparclinux@vger.kernel.org
---
 arch/sparc/kernel/ldc.c |   16 ++++------------
 arch/sparc/mm/sun4c.c   |   17 +++++------------
 2 files changed, 9 insertions(+), 24 deletions(-)

diff --git a/arch/sparc/kernel/ldc.c b/arch/sparc/kernel/ldc.c
index cb3c72c..cefd05e 100644
--- a/arch/sparc/kernel/ldc.c
+++ b/arch/sparc/kernel/ldc.c
@@ -14,6 +14,7 @@
 #include <linux/interrupt.h>
 #include <linux/list.h>
 #include <linux/init.h>
+#include <linux/bitmap.h>
 
 #include <asm/hypervisor.h>
 #include <asm/iommu.h>
@@ -1875,7 +1876,7 @@ EXPORT_SYMBOL(ldc_read);
 static long arena_alloc(struct ldc_iommu *iommu, unsigned long npages)
 {
 	struct iommu_arena *arena = &iommu->arena;
-	unsigned long n, i, start, end, limit;
+	unsigned long n, start, end, limit;
 	int pass;
 
 	limit = arena->limit;
@@ -1883,7 +1884,7 @@ static long arena_alloc(struct ldc_iommu *iommu, unsigned long npages)
 	pass = 0;
 
 again:
-	n = find_next_zero_bit(arena->map, limit, start);
+	n = bitmap_find_next_zero_area(arena->map, limit, start, npages, 0);
 	end = n + npages;
 	if (unlikely(end >= limit)) {
 		if (likely(pass < 1)) {
@@ -1896,16 +1897,7 @@ again:
 			return -1;
 		}
 	}
-
-	for (i = n; i < end; i++) {
-		if (test_bit(i, arena->map)) {
-			start = i + 1;
-			goto again;
-		}
-	}
-
-	for (i = n; i < end; i++)
-		__set_bit(i, arena->map);
+	bitmap_set(arena->map, n, npages);
 
 	arena->hint = end;
 
diff --git a/arch/sparc/mm/sun4c.c b/arch/sparc/mm/sun4c.c
index 2ffacd6..a89baf0 100644
--- a/arch/sparc/mm/sun4c.c
+++ b/arch/sparc/mm/sun4c.c
@@ -17,6 +17,7 @@
 #include <linux/fs.h>
 #include <linux/seq_file.h>
 #include <linux/scatterlist.h>
+#include <linux/bitmap.h>
 
 #include <asm/sections.h>
 #include <asm/page.h>
@@ -1021,20 +1022,12 @@ static char *sun4c_lockarea(char *vaddr, unsigned long size)
 	npages = (((unsigned long)vaddr & ~PAGE_MASK) +
 		  size + (PAGE_SIZE-1)) >> PAGE_SHIFT;
 
-	scan = 0;
 	local_irq_save(flags);
-	for (;;) {
-		scan = find_next_zero_bit(sun4c_iobuffer_map,
-					  iobuffer_map_size, scan);
-		if ((base = scan) + npages > iobuffer_map_size) goto abend;
-		for (;;) {
-			if (scan >= base + npages) goto found;
-			if (test_bit(scan, sun4c_iobuffer_map)) break;
-			scan++;
-		}
-	}
+	base = bitmap_find_next_zero_area(sun4c_iobuffer_map, iobuffer_map_size,
+						0, npages, 0);
+	if (base >= iobuffer_map_size)
+		goto abend;
 
-found:
 	high = ((base + npages) << PAGE_SHIFT) + sun4c_iobuffer_start;
 	high = SUN4C_REAL_PGDIR_ALIGN(high);
 	while (high > sun4c_iobuffer_high) {
-- 
1.6.5.1

[PATCH 6/7] ia64: Use bitmap_find_next_zero_area

[Akinobu Mita]

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: linux-ia64@vger.kernel.org
Cc: linux-altix@sgi.com
---
 arch/ia64/sn/pci/tioca_provider.c |   19 +++++--------------
 1 files changed, 5 insertions(+), 14 deletions(-)

diff --git a/arch/ia64/sn/pci/tioca_provider.c b/arch/ia64/sn/pci/tioca_provider.c
index 35b2a27..efb4545 100644
--- a/arch/ia64/sn/pci/tioca_provider.c
+++ b/arch/ia64/sn/pci/tioca_provider.c
@@ -9,6 +9,7 @@
 #include <linux/types.h>
 #include <linux/interrupt.h>
 #include <linux/pci.h>
+#include <linux/bitmap.h>
 #include <asm/sn/sn_sal.h>
 #include <asm/sn/addrs.h>
 #include <asm/sn/io.h>
@@ -369,7 +370,7 @@ tioca_dma_d48(struct pci_dev *pdev, u64 paddr)
 static dma_addr_t
 tioca_dma_mapped(struct pci_dev *pdev, unsigned long paddr, size_t req_size)
 {
-	int i, ps, ps_shift, entry, entries, mapsize, last_entry;
+	int ps, ps_shift, entry, entries, mapsize;
 	u64 xio_addr, end_xio_addr;
 	struct tioca_common *tioca_common;
 	struct tioca_kernel *tioca_kern;
@@ -410,23 +411,13 @@ tioca_dma_mapped(struct pci_dev *pdev, unsigned long paddr, size_t req_size)
 	map = tioca_kern->ca_pcigart_pagemap;
 	mapsize = tioca_kern->ca_pcigart_entries;
 
-	entry = find_first_zero_bit(map, mapsize);
-	while (entry < mapsize) {
-		last_entry = find_next_bit(map, mapsize, entry);
-
-		if (last_entry - entry >= entries)
-			break;
-
-		entry = find_next_zero_bit(map, mapsize, last_entry);
-	}
-
-	if (entry > mapsize) {
+	entry = bitmap_find_next_zero_area(map, mapsize, 0, entries, 0);
+	if (entry >= mapsize) {
 		kfree(ca_dmamap);
 		goto map_return;
 	}
 
-	for (i = 0; i < entries; i++)
-		set_bit(entry + i, map);
+	bitmap_set(map, entry, entries);
 
 	bus_addr = tioca_kern->ca_pciap_base + (entry * ps);
 
-- 
1.6.5.1

[PATCH 7/7] genalloc: Use bitmap_find_next_zero_area

[Akinobu Mita]

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
---
 lib/genalloc.c |   33 ++++++++++++---------------------
 1 files changed, 12 insertions(+), 21 deletions(-)

diff --git a/lib/genalloc.c b/lib/genalloc.c
index eed2bdb..e67f974 100644
--- a/lib/genalloc.c
+++ b/lib/genalloc.c
@@ -11,6 +11,7 @@
  */
 
 #include <linux/module.h>
+#include <linux/bitmap.h>
 #include <linux/genalloc.h>
 
 
@@ -114,7 +115,7 @@ unsigned long gen_pool_alloc(struct gen_pool *pool, size_t size)
 	struct gen_pool_chunk *chunk;
 	unsigned long addr, flags;
 	int order = pool->min_alloc_order;
-	int nbits, bit, start_bit, end_bit;
+	int nbits, start_bit, end_bit;
 
 	if (size == 0)
 		return 0;
@@ -129,29 +130,19 @@ unsigned long gen_pool_alloc(struct gen_pool *pool, size_t size)
 		end_bit -= nbits + 1;
 
 		spin_lock_irqsave(&chunk->lock, flags);
-		bit = -1;
-		while (bit + 1 < end_bit) {
-			bit = find_next_zero_bit(chunk->bits, end_bit, bit + 1);
-			if (bit >= end_bit)
-				break;
-
-			start_bit = bit;
-			if (nbits > 1) {
-				bit = find_next_bit(chunk->bits, bit + nbits,
-							bit + 1);
-				if (bit - start_bit < nbits)
-					continue;
-			}
-
-			addr = chunk->start_addr +
-					    ((unsigned long)start_bit << order);
-			while (nbits--)
-				__set_bit(start_bit++, chunk->bits);
+		start_bit = bitmap_find_next_zero_area(chunk->bits, end_bit, 0,
+						nbits, 0);
+		if (start_bit >= end_bit) {
 			spin_unlock_irqrestore(&chunk->lock, flags);
-			read_unlock(&pool->lock);
-			return addr;
+			continue;
 		}
+
+		addr = chunk->start_addr + ((unsigned long)start_bit << order);
+
+		bitmap_set(chunk->bits, start_bit, nbits);
 		spin_unlock_irqrestore(&chunk->lock, flags);
+		read_unlock(&pool->lock);
+		return addr;
 	}
 	read_unlock(&pool->lock);
 	return 0;
-- 
1.6.5.1

Re: [PATCH 1/7] bitmap: Introduce bitmap_set, bitmap_clear, bitmap_find_next_zero_area

[Andrew Morton]

Why were these patches resent?  What changed?

Everybody who is going to review these patches has already reviewed
them and now they need to review them all again?

Re: [PATCH 1/7] bitmap: Introduce bitmap_set, bitmap_clear, bitmap_find_next_zero_area

[Akinobu Mita]

2009/10/29 Andrew Morton <akpm@linux-foundation.org>:
>
> Why were these patches resent?  What changed?
>
> Everybody who is going to review these patches has already reviewed
> them and now they need to review them all again?

I resent the patches because the iommu-helper change was not correct
and I introduced serious bug in bitmap_find_next_zero_area()
if align_mask != 0 in follow-up patch then those were dropped from
the -mm tree.

Only [PATCH 1/7] and [PATCH 2/7] have changes since the first submission of
this patch set.

* [PATCH 1/7]
- Rewrite bitmap_set() and bitmap_clear()
- Let bitmap_find_next_zero_area() check the last bit of the limit
- Add kerneldoc for bitmap_find_next_zero_area()

* [PATCH 2/7]
- Convert find_next_zero_area() to use bitmap_find_next_zero_area() correctly
  iommu-helper doesn't want to search the last bit of the limist in bitmap

* [PATCH 3/7] - [PATCH 7/7]
- No changes