bitmap: replace bitmap_{from,to}_u32array

with bitmap_{from,to}_arr32 over the kernel. Additionally to it:
* __check_eq_bitmap() now takes single nbits argument.
* __check_eq_u32_array is not used in new test but may be used in
  future. So I don't remove it here, but annotate as __used.

Tested on arm64 and 32-bit BE mips.

[arnd@arndb.de: perf: arm_dsu_pmu: convert to bitmap_from_arr32]
  Link: http://lkml.kernel.org/r/20180201172508.5739-2-ynorov@caviumnetworks.com
[ynorov@caviumnetworks.com: fix net/core/ethtool.c]
  Link: http://lkml.kernel.org/r/20180205071747.4ekxtsbgxkj5b2fz@yury-thinkpad
Link: http://lkml.kernel.org/r/20171228150019.27953-2-ynorov@caviumnetworks.com
Signed-off-by: Yury Norov <ynorov@caviumnetworks.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: David Decotigny <decot@googlers.com>,
Cc: David S. Miller <davem@davemloft.net>,
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 31 insertions, 262 deletions

diff --git a/lib/bitmap.c b/lib/bitmap.c
index 47fe6441562c..9e498c77ed0e 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -1106,93 +1106,6 @@ int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order)
 EXPORT_SYMBOL(bitmap_allocate_region);
 
 /**
- * bitmap_from_u32array - copy the contents of a u32 array of bits to bitmap
- *	@bitmap: array of unsigned longs, the destination bitmap, non NULL
- *	@nbits: number of bits in @bitmap
- *	@buf: array of u32 (in host byte order), the source bitmap, non NULL
- *	@nwords: number of u32 words in @buf
- *
- * copy min(nbits, 32*nwords) bits from @buf to @bitmap, remaining
- * bits between nword and nbits in @bitmap (if any) are cleared. In
- * last word of @bitmap, the bits beyond nbits (if any) are kept
- * unchanged.
- *
- * Return the number of bits effectively copied.
- */
-unsigned int
-bitmap_from_u32array(unsigned long *bitmap, unsigned int nbits,
-		     const u32 *buf, unsigned int nwords)
-{
-	unsigned int dst_idx, src_idx;
-
-	for (src_idx = dst_idx = 0; dst_idx < BITS_TO_LONGS(nbits); ++dst_idx) {
-		unsigned long part = 0;
-
-		if (src_idx < nwords)
-			part = buf[src_idx++];
-
-#if BITS_PER_LONG == 64
-		if (src_idx < nwords)
-			part |= ((unsigned long) buf[src_idx++]) << 32;
-#endif
-
-		if (dst_idx < nbits/BITS_PER_LONG)
-			bitmap[dst_idx] = part;
-		else {
-			unsigned long mask = BITMAP_LAST_WORD_MASK(nbits);
-
-			bitmap[dst_idx] = (bitmap[dst_idx] & ~mask)
-				| (part & mask);
-		}
-	}
-
-	return min_t(unsigned int, nbits, 32*nwords);
-}
-EXPORT_SYMBOL(bitmap_from_u32array);
-
-/**
- * bitmap_to_u32array - copy the contents of bitmap to a u32 array of bits
- *	@buf: array of u32 (in host byte order), the dest bitmap, non NULL
- *	@nwords: number of u32 words in @buf
- *	@bitmap: array of unsigned longs, the source bitmap, non NULL
- *	@nbits: number of bits in @bitmap
- *
- * copy min(nbits, 32*nwords) bits from @bitmap to @buf. Remaining
- * bits after nbits in @buf (if any) are cleared.
- *
- * Return the number of bits effectively copied.
- */
-unsigned int
-bitmap_to_u32array(u32 *buf, unsigned int nwords,
-		   const unsigned long *bitmap, unsigned int nbits)
-{
-	unsigned int dst_idx = 0, src_idx = 0;
-
-	while (dst_idx < nwords) {
-		unsigned long part = 0;
-
-		if (src_idx < BITS_TO_LONGS(nbits)) {
-			part = bitmap[src_idx];
-			if (src_idx >= nbits/BITS_PER_LONG)
-				part &= BITMAP_LAST_WORD_MASK(nbits);
-			src_idx++;
-		}
-
-		buf[dst_idx++] = part & 0xffffffffUL;
-
-#if BITS_PER_LONG == 64
-		if (dst_idx < nwords) {
-			part >>= 32;
-			buf[dst_idx++] = part & 0xffffffffUL;
-		}
-#endif
-	}
-
-	return min_t(unsigned int, nbits, 32*nwords);
-}
-EXPORT_SYMBOL(bitmap_to_u32array);
-
-/**
  * bitmap_copy_le - copy a bitmap, putting the bits into little-endian order.
  * @dst:   destination buffer
  * @src:   bitmap to copy
diff --git a/lib/test_bitmap.c b/lib/test_bitmap.c
index aa1f2669bdd5..de7ef2996a07 100644
--- a/lib/test_bitmap.c
+++ b/lib/test_bitmap.c
@@ -23,7 +23,7 @@ __check_eq_uint(const char *srcfile, unsigned int line,
 		const unsigned int exp_uint, unsigned int x)
 {
 	if (exp_uint != x) {
-		pr_warn("[%s:%u] expected %u, got %u\n",
+		pr_err("[%s:%u] expected %u, got %u\n",
 			srcfile, line, exp_uint, x);
 		return false;
 	}
@@ -33,19 +33,13 @@ __check_eq_uint(const char *srcfile, unsigned int line,
 
 static bool __init
 __check_eq_bitmap(const char *srcfile, unsigned int line,
-		  const unsigned long *exp_bmap, unsigned int exp_nbits,
-		  const unsigned long *bmap, unsigned int nbits)
+		  const unsigned long *exp_bmap, const unsigned long *bmap,
+		  unsigned int nbits)
 {
-	if (exp_nbits != nbits) {
-		pr_warn("[%s:%u] bitmap length mismatch: expected %u, got %u\n",
-			srcfile, line, exp_nbits, nbits);
-		return false;
-	}
-
 	if (!bitmap_equal(exp_bmap, bmap, nbits)) {
 		pr_warn("[%s:%u] bitmaps contents differ: expected \"%*pbl\", got \"%*pbl\"\n",
 			srcfile, line,
-			exp_nbits, exp_bmap, nbits, bmap);
+			nbits, exp_bmap, nbits, bmap);
 		return false;
 	}
 	return true;
@@ -69,6 +63,10 @@ __check_eq_pbl(const char *srcfile, unsigned int line,
 static bool __init
 __check_eq_u32_array(const char *srcfile, unsigned int line,
 		     const u32 *exp_arr, unsigned int exp_len,
+		     const u32 *arr, unsigned int len) __used;
+static bool __init
+__check_eq_u32_array(const char *srcfile, unsigned int line,
+		     const u32 *exp_arr, unsigned int exp_len,
 		     const u32 *arr, unsigned int len)
 {
 	if (exp_len != len) {
@@ -255,171 +253,29 @@ static void __init test_bitmap_parselist(void)
 	}
 }
 
-static void __init test_bitmap_u32_array_conversions(void)
+static void __init test_bitmap_arr32(void)
 {
-	DECLARE_BITMAP(bmap1, 1024);
-	DECLARE_BITMAP(bmap2, 1024);
-	u32 exp_arr[32], arr[32];
-	unsigned nbits;
-
-	for (nbits = 0 ; nbits < 257 ; ++nbits) {
-		const unsigned int used_u32s = DIV_ROUND_UP(nbits, 32);
-		unsigned int i, rv;
-
-		bitmap_zero(bmap1, nbits);
-		bitmap_set(bmap1, nbits, 1024 - nbits);  /* garbage */
-
-		memset(arr, 0xff, sizeof(arr));
-		rv = bitmap_to_u32array(arr, used_u32s, bmap1, nbits);
-		expect_eq_uint(nbits, rv);
-
-		memset(exp_arr, 0xff, sizeof(exp_arr));
-		memset(exp_arr, 0, used_u32s*sizeof(*exp_arr));
-		expect_eq_u32_array(exp_arr, 32, arr, 32);
-
-		bitmap_fill(bmap2, 1024);
-		rv = bitmap_from_u32array(bmap2, nbits, arr, used_u32s);
-		expect_eq_uint(nbits, rv);
-		expect_eq_bitmap(bmap1, 1024, bmap2, 1024);
-
-		for (i = 0 ; i < nbits ; ++i) {
-			/*
-			 * test conversion bitmap -> u32[]
-			 */
-
-			bitmap_zero(bmap1, 1024);
-			__set_bit(i, bmap1);
-			bitmap_set(bmap1, nbits, 1024 - nbits);  /* garbage */
-
-			memset(arr, 0xff, sizeof(arr));
-			rv = bitmap_to_u32array(arr, used_u32s, bmap1, nbits);
-			expect_eq_uint(nbits, rv);
-
-			/* 1st used u32 words contain expected bit set, the
-			 * remaining words are left unchanged (0xff)
-			 */
-			memset(exp_arr, 0xff, sizeof(exp_arr));
-			memset(exp_arr, 0, used_u32s*sizeof(*exp_arr));
-			exp_arr[i/32] = (1U<<(i%32));
-			expect_eq_u32_array(exp_arr, 32, arr, 32);
-
-
-			/* same, with longer array to fill
-			 */
-			memset(arr, 0xff, sizeof(arr));
-			rv = bitmap_to_u32array(arr, 32, bmap1, nbits);
-			expect_eq_uint(nbits, rv);
-
-			/* 1st used u32 words contain expected bit set, the
-			 * remaining words are all 0s
-			 */
-			memset(exp_arr, 0, sizeof(exp_arr));
-			exp_arr[i/32] = (1U<<(i%32));
-			expect_eq_u32_array(exp_arr, 32, arr, 32);
-
-			/*
-			 * test conversion u32[] -> bitmap
-			 */
-
-			/* the 1st nbits of bmap2 are identical to
-			 * bmap1, the remaining bits of bmap2 are left
-			 * unchanged (all 1s)
-			 */
-			bitmap_fill(bmap2, 1024);
-			rv = bitmap_from_u32array(bmap2, nbits,
-						  exp_arr, used_u32s);
-			expect_eq_uint(nbits, rv);
-
-			expect_eq_bitmap(bmap1, 1024, bmap2, 1024);
-
-			/* same, with more bits to fill
-			 */
-			memset(arr, 0xff, sizeof(arr));  /* garbage */
-			memset(arr, 0, used_u32s*sizeof(u32));
-			arr[i/32] = (1U<<(i%32));
-
-			bitmap_fill(bmap2, 1024);
-			rv = bitmap_from_u32array(bmap2, 1024, arr, used_u32s);
-			expect_eq_uint(used_u32s*32, rv);
-
-			/* the 1st nbits of bmap2 are identical to
-			 * bmap1, the remaining bits of bmap2 are cleared
-			 */
-			bitmap_zero(bmap1, 1024);
-			__set_bit(i, bmap1);
-			expect_eq_bitmap(bmap1, 1024, bmap2, 1024);
-
-
-			/*
-			 * test short conversion bitmap -> u32[] (1
-			 * word too short)
-			 */
-			if (used_u32s > 1) {
-				bitmap_zero(bmap1, 1024);
-				__set_bit(i, bmap1);
-				bitmap_set(bmap1, nbits,
-					   1024 - nbits);  /* garbage */
-				memset(arr, 0xff, sizeof(arr));
-
-				rv = bitmap_to_u32array(arr, used_u32s - 1,
-							bmap1, nbits);
-				expect_eq_uint((used_u32s - 1)*32, rv);
-
-				/* 1st used u32 words contain expected
-				 * bit set, the remaining words are
-				 * left unchanged (0xff)
-				 */
-				memset(exp_arr, 0xff, sizeof(exp_arr));
-				memset(exp_arr, 0,
-				       (used_u32s-1)*sizeof(*exp_arr));
-				if ((i/32) < (used_u32s - 1))
-					exp_arr[i/32] = (1U<<(i%32));
-				expect_eq_u32_array(exp_arr, 32, arr, 32);
-			}
-
-			/*
-			 * test short conversion u32[] -> bitmap (3
-			 * bits too short)
-			 */
-			if (nbits > 3) {
-				memset(arr, 0xff, sizeof(arr));  /* garbage */
-				memset(arr, 0, used_u32s*sizeof(*arr));
-				arr[i/32] = (1U<<(i%32));
-
-				bitmap_zero(bmap1, 1024);
-				rv = bitmap_from_u32array(bmap1, nbits - 3,
-							  arr, used_u32s);
-				expect_eq_uint(nbits - 3, rv);
-
-				/* we are expecting the bit < nbits -
-				 * 3 (none otherwise), and the rest of
-				 * bmap1 unchanged (0-filled)
-				 */
-				bitmap_zero(bmap2, 1024);
-				if (i < nbits - 3)
-					__set_bit(i, bmap2);
-				expect_eq_bitmap(bmap2, 1024, bmap1, 1024);
-
-				/* do the same with bmap1 initially
-				 * 1-filled
-				 */
-
-				bitmap_fill(bmap1, 1024);
-				rv = bitmap_from_u32array(bmap1, nbits - 3,
-							 arr, used_u32s);
-				expect_eq_uint(nbits - 3, rv);
-
-				/* we are expecting the bit < nbits -
-				 * 3 (none otherwise), and the rest of
-				 * bmap1 unchanged (1-filled)
-				 */
-				bitmap_zero(bmap2, 1024);
-				if (i < nbits - 3)
-					__set_bit(i, bmap2);
-				bitmap_set(bmap2, nbits-3, 1024 - nbits + 3);
-				expect_eq_bitmap(bmap2, 1024, bmap1, 1024);
-			}
-		}
+	unsigned int nbits, next_bit, len = sizeof(exp) * 8;
+	u32 arr[sizeof(exp) / 4];
+	DECLARE_BITMAP(bmap2, len);
+
+	memset(arr, 0xa5, sizeof(arr));
+
+	for (nbits = 0; nbits < len; ++nbits) {
+		bitmap_to_arr32(arr, exp, nbits);
+		bitmap_from_arr32(bmap2, arr, nbits);
+		expect_eq_bitmap(bmap2, exp, nbits);
+
+		next_bit = find_next_bit(bmap2,
+				round_up(nbits, BITS_PER_LONG), nbits);
+		if (next_bit < round_up(nbits, BITS_PER_LONG))
+			pr_err("bitmap_copy_arr32(nbits == %d:"
+				" tail is not safely cleared: %d\n",
+				nbits, next_bit);
+
+		if (nbits < len - 32)
+			expect_eq_uint(arr[DIV_ROUND_UP(nbits, 32)],
+								0xa5a5a5a5);
 	}
 }
 
@@ -454,7 +310,7 @@ static void noinline __init test_mem_optimisations(void)
 static int __init test_bitmap_init(void)
 {
 	test_zero_fill_copy();
-	test_bitmap_u32_array_conversions();
+	test_bitmap_arr32();
 	test_bitmap_parselist();
 	test_mem_optimisations();