iommu-helper: use bitmap library

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: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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,

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,

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>
@@ -1162,7 +1162,7 @@ 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);
 
 }
 

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>
@@ -212,7 +212,7 @@ 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);
 }
@@ -303,7 +303,7 @@ 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);
 }

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>
@@ -126,7 +126,7 @@ 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);
@@ -792,7 +792,7 @@ int __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);
 
 	pr_info("PCI-DMA: Reserving %luMB of IOMMU area in the AGP aperture\n",
 	       iommu_size >> 20);

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);

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)
 {