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* [PATCH v3 0/4] Introduce the for_each_set_clump macro
@ 2020-04-28 23:03 Syed Nayyar Waris
  2020-04-28 23:04 ` [PATCH v3 1/4] bitops: Introduce the " Syed Nayyar Waris
                   ` (3 more replies)
  0 siblings, 4 replies; 13+ messages in thread
From: Syed Nayyar Waris @ 2020-04-28 23:03 UTC (permalink / raw)
  To: akpm
  Cc: andriy.shevchenko, vilhelm.gray, michal.simek, arnd, rrichter,
	linus.walleij, bgolaszewski, yamada.masahiro, rui.zhang,
	daniel.lezcano, amit.kucheria, linux-arch, linux-gpio,
	linux-kernel, linux-arm-kernel, linux-pm

This patchset introduces a new generic version of for_each_set_clump. 
The previous version of for_each_set_clump8 used a fixed size 8-bit
clump, but the new generic version can work with clump of any size but
less than or equal to BITS_PER_LONG. The patchset utilizes the new macro 
in several GPIO drivers.

The earlier 8-bit for_each_set_clump8 facilitated a
for-loop syntax that iterates over a memory region entire groups of set
bits at a time.

For example, suppose you would like to iterate over a 32-bit integer 8
bits at a time, skipping over 8-bit groups with no set bit, where
XXXXXXXX represents the current 8-bit group:

    Example:        10111110 00000000 11111111 00110011
    First loop:     10111110 00000000 11111111 XXXXXXXX
    Second loop:    10111110 00000000 XXXXXXXX 00110011
    Third loop:     XXXXXXXX 00000000 11111111 00110011

Each iteration of the loop returns the next 8-bit group that has at
least one set bit.

But with the new for_each_set_clump the clump size can be different from 8 bits.
Moreover, the clump can be split at word boundary in situations where word 
size is not multiple of clump size. Following are examples showing the working 
of new macro for clump sizes of 24 bits and 6 bits.

Example 1:
clump size: 24 bits, Number of clumps (or ports): 10
bitmap stores the bit information from where successive clumps are retrieved.

     /* bitmap memory region */
        0x00aa0000ff000000;  /* Most significant bits */
        0xaaaaaa0000ff0000;
        0x000000aa000000aa;
        0xbbbbabcdeffedcba;  /* Least significant bits */

Different iterations of for_each_set_clump:-
'offset' is the bit position and 'clump' is the 24 bit clump from the
above bitmap.
Iteration first:        offset: 0 clump: 0xfedcba
Iteration second:       offset: 24 clump: 0xabcdef
Iteration third:        offset: 48 clump: 0xaabbbb
Iteration fourth:       offset: 96 clump: 0xaa
Iteration fifth:        offset: 144 clump: 0xff
Iteration sixth:        offset: 168 clump: 0xaaaaaa
Iteration seventh:      offset: 216 clump: 0xff
Loop breaks because in the end the remaining bits (0x00aa) size was less
than clump size of 24 bits.

In above example it can be seen that in iteration third, the 24 bit clump
that was retrieved was split between bitmap[0] and bitmap[1]. This example 
also shows that 24 bit zeroes if present in between, were skipped (preserving
the previous for_each_set_macro8 behaviour). 

Example 2:
clump size = 6 bits, Number of clumps (or ports) = 3.

     /* bitmap memory region */
        0x00aa0000ff000000;  /* Most significant bits */
        0xaaaaaa0000ff0000;
        0x0f00000000000000;
        0x0000000000000ac0;  /* Least significant bits */

Different iterations of for_each_set_clump:
'offset' is the bit position and 'clump' is the 6 bit clump from the
above bitmap.
Iteration first:        offset: 6 clump: 0x2b
Loop breaks because 6 * 3 = 18 bits traversed in bitmap.
Here 6 * 3 is clump size * no. of clumps.

Changes in v3:
 - Patch 3: Change datatype of some variables from u64 to unsigned long
   in function thunderx_gpio_set_multiple.

CHanges in v2:
 - Patch 2: Unify different tests for 'for_each_set_clump'. Pass test data as
   function parameters.
 - Patch 2: Remove unnecessary bitmap_zero calls.

Syed Nayyar Waris (4):
  bitops: Introduce the the for_each_set_clump macro
  lib/test_bitmap.c: Add for_each_set_clump test cases
  gpio: thunderx: Utilize for_each_set_clump macro
  gpio: xilinx: Utilize for_each_set_clump macro

 drivers/gpio/gpio-thunderx.c      |  12 ++-
 drivers/gpio/gpio-xilinx.c        |  64 ++++++++--------
 include/asm-generic/bitops/find.h |  19 +++++
 include/linux/bitmap.h            |  61 +++++++++++++++
 include/linux/bitops.h            |  13 ++++
 lib/find_bit.c                    |  14 ++++
 lib/test_bitmap.c                 | 121 ++++++++++++++++++++++++++++++
 7 files changed, 270 insertions(+), 34 deletions(-)


base-commit: a9509b8ee069a06cd14334edca904bd0607622ca
-- 
2.26.2


^ permalink raw reply	[flat|nested] 13+ messages in thread

* [PATCH v3 1/4] bitops: Introduce the the for_each_set_clump macro
  2020-04-28 23:03 [PATCH v3 0/4] Introduce the for_each_set_clump macro Syed Nayyar Waris
@ 2020-04-28 23:04 ` Syed Nayyar Waris
  2020-04-28 23:05 ` [PATCH v3 2/4] lib/test_bitmap.c: Add for_each_set_clump test cases Syed Nayyar Waris
                   ` (2 subsequent siblings)
  3 siblings, 0 replies; 13+ messages in thread
From: Syed Nayyar Waris @ 2020-04-28 23:04 UTC (permalink / raw)
  To: akpm
  Cc: andriy.shevchenko, vilhelm.gray, arnd, linus.walleij, linux-arch,
	linux-kernel

This macro iterates for each group of bits (clump) with set bits,
within a bitmap memory region. For each iteration, "start" is set to
the bit offset of the found clump, while the respective clump value is
stored to the location pointed by "clump". Additionally, the
bitmap_get_value and bitmap_set_value functions are introduced to
respectively get and set a value of n-bits in a bitmap memory region.
The n-bits can have any size less than or equal to BITS_PER_LONG.
Moreover, during setting value of n-bit in bitmap, if a situation arise
that the width of next n-bit is exceeding the word boundary, then it
will divide itself such that some portion of it is stored in that word,
while the remaining portion is stored in the next higher word. Similar
situation occurs while retrieving value of n-bits from bitmap.

Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Syed Nayyar Waris <syednwaris@gmail.com>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
---
Changes in v3:
 - No change

Changes in v2:
 - No change

 include/asm-generic/bitops/find.h | 19 ++++++++++
 include/linux/bitmap.h            | 61 +++++++++++++++++++++++++++++++
 include/linux/bitops.h            | 13 +++++++
 lib/find_bit.c                    | 14 +++++++
 4 files changed, 107 insertions(+)

diff --git a/include/asm-generic/bitops/find.h b/include/asm-generic/bitops/find.h
index 9fdf21302fdf..4e6600759455 100644
--- a/include/asm-generic/bitops/find.h
+++ b/include/asm-generic/bitops/find.h
@@ -97,4 +97,23 @@ extern unsigned long find_next_clump8(unsigned long *clump,
 #define find_first_clump8(clump, bits, size) \
 	find_next_clump8((clump), (bits), (size), 0)
 
+/**
+ * find_next_clump - find next clump with set bits in a memory region
+ * @clump: location to store copy of found clump
+ * @addr: address to base the search on
+ * @size: bitmap size in number of bits
+ * @offset: bit offset at which to start searching
+ * @clump_size: clump size in bits
+ *
+ * Returns the bit offset for the next set clump; the found clump value is
+ * copied to the location pointed by @clump. If no bits are set, returns @size.
+ */
+extern unsigned long find_next_clump(unsigned long *clump,
+				      const unsigned long *addr,
+				      unsigned long size, unsigned long offset,
+				      unsigned long clump_size);
+
+#define find_first_clump(clump, bits, size, clump_size) \
+	find_next_clump((clump), (bits), (size), 0, (clump_size))
+
 #endif /*_ASM_GENERIC_BITOPS_FIND_H_ */
diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h
index 99058eb81042..7ab2c65fc964 100644
--- a/include/linux/bitmap.h
+++ b/include/linux/bitmap.h
@@ -75,7 +75,11 @@
  *  bitmap_from_arr32(dst, buf, nbits)          Copy nbits from u32[] buf to dst
  *  bitmap_to_arr32(buf, src, nbits)            Copy nbits from buf to u32[] dst
  *  bitmap_get_value8(map, start)               Get 8bit value from map at start
+ *  bitmap_get_value(map, start, nbits)		Get bit value of size
+ *						'nbits' from map at start
  *  bitmap_set_value8(map, value, start)        Set 8bit value to map at start
+ *  bitmap_set_value(map, value, start, nbits)	Set bit value of size 'nbits'
+ *						of map at start
  *
  * Note, bitmap_zero() and bitmap_fill() operate over the region of
  * unsigned longs, that is, bits behind bitmap till the unsigned long
@@ -563,6 +567,34 @@ static inline unsigned long bitmap_get_value8(const unsigned long *map,
 	return (map[index] >> offset) & 0xFF;
 }
 
+/**
+ * bitmap_get_value - get a value of n-bits from the memory region
+ * @map: address to the bitmap memory region
+ * @start: bit offset of the n-bit value
+ * @nbits: size of value in bits
+ *
+ * Returns value of nbits located at the @start bit offset within the @map
+ * memory region.
+ */
+static inline unsigned long bitmap_get_value(const unsigned long *map,
+					      unsigned long start,
+					      unsigned long nbits)
+{
+	const size_t index = BIT_WORD(start);
+	const unsigned long offset = start % BITS_PER_LONG;
+	const unsigned long ceiling = roundup(start + 1, BITS_PER_LONG);
+	const unsigned long space = ceiling - start;
+	unsigned long value_low, value_high;
+
+	if (space >= nbits)
+		return (map[index] >> offset) & GENMASK(nbits - 1, 0);
+	else {
+		value_low = map[index] & BITMAP_FIRST_WORD_MASK(start);
+		value_high = map[index + 1] & BITMAP_LAST_WORD_MASK(start + nbits);
+		return (value_low >> offset) | (value_high << space);
+	}
+}
+
 /**
  * bitmap_set_value8 - set an 8-bit value within a memory region
  * @map: address to the bitmap memory region
@@ -579,6 +611,35 @@ static inline void bitmap_set_value8(unsigned long *map, unsigned long value,
 	map[index] |= value << offset;
 }
 
+/**
+ * bitmap_set_value - set n-bit value within a memory region
+ * @map: address to the bitmap memory region
+ * @value: value of nbits
+ * @start: bit offset of the n-bit value
+ * @nbits: size of value in bits
+ */
+static inline void bitmap_set_value(unsigned long *map,
+				    unsigned long value,
+				    unsigned long start, unsigned long nbits)
+{
+	const size_t index = BIT_WORD(start);
+	const unsigned long offset = start % BITS_PER_LONG;
+	const unsigned long ceiling = roundup(start + 1, BITS_PER_LONG);
+	const unsigned long space = ceiling - start;
+
+	value &= GENMASK(nbits - 1, 0);
+
+	if (space >= nbits) {
+		map[index] &= ~(GENMASK(nbits + offset - 1, offset));
+		map[index] |= value << offset;
+	} else {
+		map[index] &= ~BITMAP_FIRST_WORD_MASK(start);
+		map[index] |= value << offset;
+		map[index + 1] &= ~BITMAP_LAST_WORD_MASK(start + nbits);
+		map[index + 1] |= (value >> space);
+	}
+}
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* __LINUX_BITMAP_H */
diff --git a/include/linux/bitops.h b/include/linux/bitops.h
index 9acf654f0b19..41c2d9ce63e7 100644
--- a/include/linux/bitops.h
+++ b/include/linux/bitops.h
@@ -62,6 +62,19 @@ extern unsigned long __sw_hweight64(__u64 w);
 	     (start) < (size); \
 	     (start) = find_next_clump8(&(clump), (bits), (size), (start) + 8))
 
+/**
+ * for_each_set_clump - iterate over bitmap for each clump with set bits
+ * @start: bit offset to start search and to store the current iteration offset
+ * @clump: location to store copy of current 8-bit clump
+ * @bits: bitmap address to base the search on
+ * @size: bitmap size in number of bits
+ * @clump_size: clump size in bits
+ */
+#define for_each_set_clump(start, clump, bits, size, clump_size) \
+	for ((start) = find_first_clump(&(clump), (bits), (size), (clump_size)); \
+	     (start) < (size); \
+	     (start) = find_next_clump(&(clump), (bits), (size), (start) + (clump_size), (clump_size)))
+
 static inline int get_bitmask_order(unsigned int count)
 {
 	int order;
diff --git a/lib/find_bit.c b/lib/find_bit.c
index 49f875f1baf7..1341bd39b32a 100644
--- a/lib/find_bit.c
+++ b/lib/find_bit.c
@@ -190,3 +190,17 @@ unsigned long find_next_clump8(unsigned long *clump, const unsigned long *addr,
 	return offset;
 }
 EXPORT_SYMBOL(find_next_clump8);
+
+unsigned long find_next_clump(unsigned long *clump, const unsigned long *addr,
+			       unsigned long size, unsigned long offset,
+			       unsigned long clump_size)
+{
+	offset = find_next_bit(addr, size, offset);
+	if (offset == size)
+		return size;
+
+	offset = rounddown(offset, clump_size);
+	*clump = bitmap_get_value(addr, offset, clump_size);
+	return offset;
+}
+EXPORT_SYMBOL(find_next_clump);
-- 
2.26.2


^ permalink raw reply related	[flat|nested] 13+ messages in thread

* [PATCH v3 2/4] lib/test_bitmap.c: Add for_each_set_clump test cases
  2020-04-28 23:03 [PATCH v3 0/4] Introduce the for_each_set_clump macro Syed Nayyar Waris
  2020-04-28 23:04 ` [PATCH v3 1/4] bitops: Introduce the " Syed Nayyar Waris
@ 2020-04-28 23:05 ` Syed Nayyar Waris
  2020-04-29 10:16   ` Andy Shevchenko
  2020-04-28 23:07 ` [PATCH v3 3/4] gpio: thunderx: Utilize for_each_set_clump macro Syed Nayyar Waris
  2020-04-28 23:09 ` [PATCH v3 4/4] gpio: xilinx: " Syed Nayyar Waris
  3 siblings, 1 reply; 13+ messages in thread
From: Syed Nayyar Waris @ 2020-04-28 23:05 UTC (permalink / raw)
  To: akpm; +Cc: andriy.shevchenko, vilhelm.gray, linus.walleij, linux-kernel

The introduction of the generic for_each_set_clump macro need test
cases to verify the implementation. This patch adds test cases for
scenarios in which clump sizes are 8 bits, 24 bits, 30 bits and 6 bits.
The cases contain situations where clump is getting split at the word
boundary and also when zeroes are present in the start and middle of
bitmap.

Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Syed Nayyar Waris <syednwaris@gmail.com>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
---
Changes in v3:
 - No CHange.

Changes in v2:
 - Unify different tests for 'for_each_set_clump'. Pass test data as
   function parameters.
 - Remove unnecessary bitmap_zero calls.

 lib/test_bitmap.c | 121 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 121 insertions(+)

diff --git a/lib/test_bitmap.c b/lib/test_bitmap.c
index 6b13150667f5..13fe9a2e752e 100644
--- a/lib/test_bitmap.c
+++ b/lib/test_bitmap.c
@@ -155,6 +155,38 @@ static bool __init __check_eq_clump8(const char *srcfile, unsigned int line,
 	return true;
 }
 
+static bool __init __check_eq_clump(const char *srcfile, unsigned int line,
+				    const unsigned int offset,
+				    const unsigned int size,
+				    const unsigned long *const clump_exp,
+				    const unsigned long *const clump,
+				    const unsigned long clump_size)
+{
+	unsigned long exp;
+
+	if (offset >= size) {
+		pr_warn("[%s:%u] bit offset for clump out-of-bounds: expected less than %u, got %u\n",
+			srcfile, line, size, offset);
+		return false;
+	}
+
+	exp = clump_exp[offset / clump_size];
+	if (!exp) {
+		pr_warn("[%s:%u] bit offset for zero clump: expected nonzero clump, got bit offset %u with clump value 0",
+			srcfile, line, offset);
+		return false;
+	}
+
+	if (*clump != exp) {
+		pr_warn("[%s:%u] expected clump value of 0x%lX, got clump value of 0x%lX",
+			srcfile, line, exp, *clump);
+		return false;
+	}
+
+	return true;
+}
+
+
 #define __expect_eq(suffix, ...)					\
 	({								\
 		int result = 0;						\
@@ -172,6 +204,7 @@ static bool __init __check_eq_clump8(const char *srcfile, unsigned int line,
 #define expect_eq_pbl(...)		__expect_eq(pbl, ##__VA_ARGS__)
 #define expect_eq_u32_array(...)	__expect_eq(u32_array, ##__VA_ARGS__)
 #define expect_eq_clump8(...)		__expect_eq(clump8, ##__VA_ARGS__)
+#define expect_eq_clump(...)		__expect_eq(clump, ##__VA_ARGS__)
 
 static void __init test_zero_clear(void)
 {
@@ -588,6 +621,46 @@ static const unsigned char clump_exp[] __initconst = {
 	0x05,	/* non-adjacent 2 bits set */
 };
 
+static const unsigned long clump_exp1[] __initconst = {
+	0x01,	/* 1 bit set */
+	0x02,	/* non-edge 1 bit set */
+	0x00,	/* zero bits set */
+	0x38,	/* 3 bits set across 4-bit boundary */
+	0x38,	/* Repeated clump */
+	0x0F,	/* 4 bits set */
+	0xFF,	/* all bits set */
+	0x05,	/* non-adjacent 2 bits set */
+};
+
+static const unsigned long clump_exp2[] __initconst = {
+	0xfedcba,	/* 24 bits */
+	0xabcdef,
+	0xaabbbb,	/* Clump split between 2 words */
+	0x000000,	/* zeroes in between */
+	0x0000aa,
+	0x000000,
+	0x0000ff,
+	0xaaaaaa,
+	0x000000,
+	0x0000ff,
+};
+
+static const unsigned long clump_exp3[] __initconst = {
+	0x00000000,	/* starting with 0s*/
+	0x00000000,	/* All 0s */
+	0x00000000,
+	0x00000000,
+	0x3f00000f,     /* Non zero set */
+	0x2aa80003,
+	0x00000aaa,
+	0x00003fc0,
+};
+
+static const unsigned long clump_exp4[] __initconst = {
+	0x00,
+	0x2b,
+};
+
 static void __init test_for_each_set_clump8(void)
 {
 #define CLUMP_EXP_NUMBITS 64
@@ -610,6 +683,53 @@ static void __init test_for_each_set_clump8(void)
 		expect_eq_clump8(start, CLUMP_EXP_NUMBITS, clump_exp, &clump);
 }
 
+static void __init execute_for_each_set_clump(unsigned long *bits,
+				unsigned long size,
+				const unsigned long *clump_exp,
+				unsigned long clump_size)
+{
+	unsigned long start, clump;
+
+	for_each_set_clump(start, clump, bits, size, clump_size)
+		expect_eq_clump(start, size, clump_exp, &clump, clump_size);
+}
+
+static void __init test_for_each_set_clump(void)
+{
+	/* common bitmap of max size for different tests */
+	DECLARE_BITMAP(bits, 256);
+
+	/* set bitmap for test case 1 with clump size as 8 bits */
+	bitmap_set_value(bits, 0x38000201, 0, 32);
+	bitmap_set_value(bits, 0x05ff0f38, 32, 32);
+
+	execute_for_each_set_clump(bits, 64, clump_exp1, 8);
+
+	/* set bitmap for test case 2 with clump size as 24 bits */
+	bitmap_set_value(bits, 0xeffedcba, 0, 32);
+	bitmap_set_value(bits, 0xbbbbabcd, 32, 32);
+	bitmap_set_value(bits, 0x000000aa, 64, 32);
+	bitmap_set_value(bits, 0x000000aa, 96, 32);
+	bitmap_set_value(bits, 0x00ff0000, 128, 32);
+	bitmap_set_value(bits, 0xaaaaaa00, 160, 32);
+	bitmap_set_value(bits, 0xff000000, 192, 32);
+	bitmap_set_value(bits, 0x00aa0000, 224, 32);
+
+	execute_for_each_set_clump(bits, 240, clump_exp2, 24);
+
+	/* set bitmap for test case 3 with clump size as 30 bits */
+	bitmap_set_value(bits, 0x00000000, 0, 32);
+	bitmap_set_value(bits, 0x00000000, 32, 32);
+	bitmap_set_value(bits, 0x00000000, 64, 32);
+	bitmap_set_value(bits, 0x0f000000, 96, 32);
+
+	execute_for_each_set_clump(bits, 240, clump_exp3, 30);
+
+	/* set bitmap for test case 4 with clump size as 6 bits */
+	bitmap_set_value(bits, 0x00000ac0, 0, 32);
+	execute_for_each_set_clump(bits, 18, clump_exp4, 6);
+}
+
 static void __init selftest(void)
 {
 	test_zero_clear();
@@ -623,6 +743,7 @@ static void __init selftest(void)
 	test_bitmap_parselist_user();
 	test_mem_optimisations();
 	test_for_each_set_clump8();
+	test_for_each_set_clump();
 }
 
 KSTM_MODULE_LOADERS(test_bitmap);
-- 
2.26.2


^ permalink raw reply related	[flat|nested] 13+ messages in thread

* [PATCH v3 3/4] gpio: thunderx: Utilize for_each_set_clump macro
  2020-04-28 23:03 [PATCH v3 0/4] Introduce the for_each_set_clump macro Syed Nayyar Waris
  2020-04-28 23:04 ` [PATCH v3 1/4] bitops: Introduce the " Syed Nayyar Waris
  2020-04-28 23:05 ` [PATCH v3 2/4] lib/test_bitmap.c: Add for_each_set_clump test cases Syed Nayyar Waris
@ 2020-04-28 23:07 ` Syed Nayyar Waris
  2020-04-29 10:17   ` Andy Shevchenko
  2020-04-28 23:09 ` [PATCH v3 4/4] gpio: xilinx: " Syed Nayyar Waris
  3 siblings, 1 reply; 13+ messages in thread
From: Syed Nayyar Waris @ 2020-04-28 23:07 UTC (permalink / raw)
  To: akpm
  Cc: andriy.shevchenko, vilhelm.gray, rrichter, linus.walleij,
	bgolaszewski, linux-gpio, linux-kernel

This patch reimplements the thunderx_gpio_set_multiple function in
drivers/gpio/gpio-thunderx.c to use the new for_each_set_clump macro.
Instead of looping for each bank in thunderx_gpio_set_multiple
function, now we can skip bank which is not set and save cycles.

Cc: Robert Richter <rrichter@marvell.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Syed Nayyar Waris <syednwaris@gmail.com>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
---
Changes in v3:
 - Change datatype of some variables from u64 to unsigned long
   in function thunderx_gpio_set_multiple to resolve build errors.

CHanges in v2:
 - No change.

 drivers/gpio/gpio-thunderx.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/gpio/gpio-thunderx.c b/drivers/gpio/gpio-thunderx.c
index 9f66deab46ea..e577ab7e9e3c 100644
--- a/drivers/gpio/gpio-thunderx.c
+++ b/drivers/gpio/gpio-thunderx.c
@@ -275,12 +275,16 @@ static void thunderx_gpio_set_multiple(struct gpio_chip *chip,
 				       unsigned long *bits)
 {
 	int bank;
-	u64 set_bits, clear_bits;
+	unsigned long set_bits, clear_bits, gpio_mask;
+	const unsigned long bank_size = 64;
+	unsigned long offset;
+
 	struct thunderx_gpio *txgpio = gpiochip_get_data(chip);
 
-	for (bank = 0; bank <= chip->ngpio / 64; bank++) {
-		set_bits = bits[bank] & mask[bank];
-		clear_bits = ~bits[bank] & mask[bank];
+	for_each_set_clump(offset, gpio_mask, mask, chip->ngpio, bank_size) {
+		bank = offset / bank_size;
+		set_bits = bits[bank] & gpio_mask;
+		clear_bits = ~bits[bank] & gpio_mask;
 		writeq(set_bits, txgpio->register_base + (bank * GPIO_2ND_BANK) + GPIO_TX_SET);
 		writeq(clear_bits, txgpio->register_base + (bank * GPIO_2ND_BANK) + GPIO_TX_CLR);
 	}
-- 
2.26.2


^ permalink raw reply related	[flat|nested] 13+ messages in thread

* [PATCH v3 4/4] gpio: xilinx: Utilize for_each_set_clump macro
  2020-04-28 23:03 [PATCH v3 0/4] Introduce the for_each_set_clump macro Syed Nayyar Waris
                   ` (2 preceding siblings ...)
  2020-04-28 23:07 ` [PATCH v3 3/4] gpio: thunderx: Utilize for_each_set_clump macro Syed Nayyar Waris
@ 2020-04-28 23:09 ` Syed Nayyar Waris
  2020-04-29 10:21   ` Andy Shevchenko
  3 siblings, 1 reply; 13+ messages in thread
From: Syed Nayyar Waris @ 2020-04-28 23:09 UTC (permalink / raw)
  To: akpm
  Cc: andriy.shevchenko, vilhelm.gray, linus.walleij, bgolaszewski,
	michal.simek, linux-gpio, linux-arm-kernel, linux-kernel

This patch reimplements the xgpio_set_multiple function in
drivers/gpio/gpio-xilinx.c to use the new for_each_set_clump macro.
Instead of looping for each bit in xgpio_set_multiple
function, now we can check each channel at a time and save cycles.

Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Cc: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Syed Nayyar Waris <syednwaris@gmail.com>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
---
Changes in v3:
 - No change.

Changes in v2:
 - No change.

 drivers/gpio/gpio-xilinx.c | 64 ++++++++++++++++++++------------------
 1 file changed, 34 insertions(+), 30 deletions(-)

diff --git a/drivers/gpio/gpio-xilinx.c b/drivers/gpio/gpio-xilinx.c
index 67f9f82e0db0..428207f9ab91 100644
--- a/drivers/gpio/gpio-xilinx.c
+++ b/drivers/gpio/gpio-xilinx.c
@@ -136,39 +136,43 @@ static void xgpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
 static void xgpio_set_multiple(struct gpio_chip *gc, unsigned long *mask,
 			       unsigned long *bits)
 {
-	unsigned long flags;
+	unsigned long flags[2];
 	struct xgpio_instance *chip = gpiochip_get_data(gc);
-	int index = xgpio_index(chip, 0);
-	int offset, i;
-
-	spin_lock_irqsave(&chip->gpio_lock[index], flags);
-
-	/* Write to GPIO signals */
-	for (i = 0; i < gc->ngpio; i++) {
-		if (*mask == 0)
-			break;
-		/* Once finished with an index write it out to the register */
-		if (index !=  xgpio_index(chip, i)) {
-			xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET +
-				       index * XGPIO_CHANNEL_OFFSET,
-				       chip->gpio_state[index]);
-			spin_unlock_irqrestore(&chip->gpio_lock[index], flags);
-			index =  xgpio_index(chip, i);
-			spin_lock_irqsave(&chip->gpio_lock[index], flags);
-		}
-		if (__test_and_clear_bit(i, mask)) {
-			offset =  xgpio_offset(chip, i);
-			if (test_bit(i, bits))
-				chip->gpio_state[index] |= BIT(offset);
-			else
-				chip->gpio_state[index] &= ~BIT(offset);
-		}
+	u32 *const state = chip->gpio_state;
+	unsigned int *const width = chip->gpio_width;
+	const unsigned long state_size = BITS_PER_TYPE(*state);
+	unsigned long offset, clump;
+	size_t index;
+
+#define TOTAL_BITS BITS_PER_TYPE(chip->gpio_state)
+	DECLARE_BITMAP(old, TOTAL_BITS);
+	DECLARE_BITMAP(new, TOTAL_BITS);
+	DECLARE_BITMAP(changed, TOTAL_BITS);
+
+	spin_lock_irqsave(&chip->gpio_lock[0], flags[0]);
+	spin_lock_irqsave(&chip->gpio_lock[1], flags[1]);
+
+	bitmap_set_value(old, state[0], 0, width[0]);
+	bitmap_set_value(old, state[1], width[0], width[1]);
+	bitmap_replace(new, old, bits, mask, gc->ngpio);
+
+	bitmap_set_value(old, state[0], 0, state_size);
+	bitmap_set_value(old, state[1], state_size, state_size);
+	state[0] = bitmap_get_value(new, 0, width[0]);
+	state[1] = bitmap_get_value(new, width[0], width[1]);
+	bitmap_set_value(new, state[0], 0, state_size);
+	bitmap_set_value(new, state[1], state_size, state_size);
+	bitmap_xor(changed, old, new, TOTAL_BITS);
+
+	for_each_set_clump(offset, clump, changed, TOTAL_BITS, state_size) {
+		index = offset / state_size;
+		xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET +
+				index * XGPIO_CHANNEL_OFFSET,
+				state[index]);
 	}
 
-	xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET +
-		       index * XGPIO_CHANNEL_OFFSET, chip->gpio_state[index]);
-
-	spin_unlock_irqrestore(&chip->gpio_lock[index], flags);
+	spin_unlock_irqrestore(&chip->gpio_lock[1], flags[1]);
+	spin_unlock_irqrestore(&chip->gpio_lock[0], flags[0]);
 }
 
 /**
-- 
2.26.2


^ permalink raw reply related	[flat|nested] 13+ messages in thread

* Re: [PATCH v3 2/4] lib/test_bitmap.c: Add for_each_set_clump test cases
  2020-04-28 23:05 ` [PATCH v3 2/4] lib/test_bitmap.c: Add for_each_set_clump test cases Syed Nayyar Waris
@ 2020-04-29 10:16   ` Andy Shevchenko
  0 siblings, 0 replies; 13+ messages in thread
From: Andy Shevchenko @ 2020-04-29 10:16 UTC (permalink / raw)
  To: Syed Nayyar Waris; +Cc: akpm, vilhelm.gray, linus.walleij, linux-kernel

On Wed, Apr 29, 2020 at 04:35:58AM +0530, Syed Nayyar Waris wrote:
> The introduction of the generic for_each_set_clump macro need test
> cases to verify the implementation. This patch adds test cases for
> scenarios in which clump sizes are 8 bits, 24 bits, 30 bits and 6 bits.
> The cases contain situations where clump is getting split at the word
> boundary and also when zeroes are present in the start and middle of
> bitmap.

...

> +static void __init test_for_each_set_clump(void)
> +{
> +	/* common bitmap of max size for different tests */
> +	DECLARE_BITMAP(bits, 256);
> +
> +	/* set bitmap for test case 1 with clump size as 8 bits */
> +	bitmap_set_value(bits, 0x38000201, 0, 32);
> +	bitmap_set_value(bits, 0x05ff0f38, 32, 32);
> +
> +	execute_for_each_set_clump(bits, 64, clump_exp1, 8);
> +
> +	/* set bitmap for test case 2 with clump size as 24 bits */
> +	bitmap_set_value(bits, 0xeffedcba, 0, 32);
> +	bitmap_set_value(bits, 0xbbbbabcd, 32, 32);
> +	bitmap_set_value(bits, 0x000000aa, 64, 32);
> +	bitmap_set_value(bits, 0x000000aa, 96, 32);
> +	bitmap_set_value(bits, 0x00ff0000, 128, 32);
> +	bitmap_set_value(bits, 0xaaaaaa00, 160, 32);
> +	bitmap_set_value(bits, 0xff000000, 192, 32);
> +	bitmap_set_value(bits, 0x00aa0000, 224, 32);
> +
> +	execute_for_each_set_clump(bits, 240, clump_exp2, 24);
> +
> +	/* set bitmap for test case 3 with clump size as 30 bits */
> +	bitmap_set_value(bits, 0x00000000, 0, 32);
> +	bitmap_set_value(bits, 0x00000000, 32, 32);
> +	bitmap_set_value(bits, 0x00000000, 64, 32);
> +	bitmap_set_value(bits, 0x0f000000, 96, 32);
> +
> +	execute_for_each_set_clump(bits, 240, clump_exp3, 30);
> +
> +	/* set bitmap for test case 4 with clump size as 6 bits */
> +	bitmap_set_value(bits, 0x00000ac0, 0, 32);
> +	execute_for_each_set_clump(bits, 18, clump_exp4, 6);

You can roll entire function into one loop

	for i in ARRAY(test_data_configuration):
		prepare_test_data()
		execute_test()

> +}

-- 
With Best Regards,
Andy Shevchenko



^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [PATCH v3 3/4] gpio: thunderx: Utilize for_each_set_clump macro
  2020-04-28 23:07 ` [PATCH v3 3/4] gpio: thunderx: Utilize for_each_set_clump macro Syed Nayyar Waris
@ 2020-04-29 10:17   ` Andy Shevchenko
  2020-04-30 16:22     ` Syed Nayyar Waris
  0 siblings, 1 reply; 13+ messages in thread
From: Andy Shevchenko @ 2020-04-29 10:17 UTC (permalink / raw)
  To: Syed Nayyar Waris
  Cc: akpm, vilhelm.gray, rrichter, linus.walleij, bgolaszewski,
	linux-gpio, linux-kernel

On Wed, Apr 29, 2020 at 04:37:41AM +0530, Syed Nayyar Waris wrote:
> This patch reimplements the thunderx_gpio_set_multiple function in
> drivers/gpio/gpio-thunderx.c to use the new for_each_set_clump macro.
> Instead of looping for each bank in thunderx_gpio_set_multiple
> function, now we can skip bank which is not set and save cycles.

> +	const unsigned long bank_size = 64;

Shouldn't be rather definition?

-- 
With Best Regards,
Andy Shevchenko



^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [PATCH v3 4/4] gpio: xilinx: Utilize for_each_set_clump macro
  2020-04-28 23:09 ` [PATCH v3 4/4] gpio: xilinx: " Syed Nayyar Waris
@ 2020-04-29 10:21   ` Andy Shevchenko
  2020-04-30 16:15     ` Syed Nayyar Waris
  0 siblings, 1 reply; 13+ messages in thread
From: Andy Shevchenko @ 2020-04-29 10:21 UTC (permalink / raw)
  To: Syed Nayyar Waris
  Cc: akpm, vilhelm.gray, linus.walleij, bgolaszewski, michal.simek,
	linux-gpio, linux-arm-kernel, linux-kernel

On Wed, Apr 29, 2020 at 04:39:47AM +0530, Syed Nayyar Waris wrote:
> This patch reimplements the xgpio_set_multiple function in
> drivers/gpio/gpio-xilinx.c to use the new for_each_set_clump macro.
> Instead of looping for each bit in xgpio_set_multiple
> function, now we can check each channel at a time and save cycles.

> +	const unsigned long state_size = BITS_PER_TYPE(*state);

This '*state' is unneeded complication, use BITS_PER_U32.

> +#define TOTAL_BITS BITS_PER_TYPE(chip->gpio_state)

This macro makes code uglier, besides the fact of absence of #undef.
And also see above.

> +	DECLARE_BITMAP(old, TOTAL_BITS);
> +	DECLARE_BITMAP(new, TOTAL_BITS);
> +	DECLARE_BITMAP(changed, TOTAL_BITS);

-- 
With Best Regards,
Andy Shevchenko



^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [PATCH v3 4/4] gpio: xilinx: Utilize for_each_set_clump macro
  2020-04-29 10:21   ` Andy Shevchenko
@ 2020-04-30 16:15     ` Syed Nayyar Waris
  2020-04-30 16:38       ` Andy Shevchenko
  0 siblings, 1 reply; 13+ messages in thread
From: Syed Nayyar Waris @ 2020-04-30 16:15 UTC (permalink / raw)
  To: Andy Shevchenko
  Cc: akpm, vilhelm.gray, linus.walleij, bgolaszewski, michal.simek,
	linux-gpio, linux-arm-kernel, linux-kernel

On Wed, Apr 29, 2020 at 01:21:14PM +0300, Andy Shevchenko wrote:
> On Wed, Apr 29, 2020 at 04:39:47AM +0530, Syed Nayyar Waris wrote:
> > This patch reimplements the xgpio_set_multiple function in
> > drivers/gpio/gpio-xilinx.c to use the new for_each_set_clump macro.
> > Instead of looping for each bit in xgpio_set_multiple
> > function, now we can check each channel at a time and save cycles.
> 
> > +	const unsigned long state_size = BITS_PER_TYPE(*state);
> 
> This '*state' is unneeded complication, use BITS_PER_U32.
> 
> > +#define TOTAL_BITS BITS_PER_TYPE(chip->gpio_state)
> 
> This macro makes code uglier, besides the fact of absence of #undef.
> And also see above.

Thank you for your review comments. Just want to clarify, you want
 a new macro to be created - 'BITS_PER_U32' ?  
Also, don't you think that with BITS_PER_TYPE(), in case later the type
of 'state' changes, it will be reflected in this code without any code
change?

Let me know if I have misunderstood something.

> 
> > +	DECLARE_BITMAP(old, TOTAL_BITS);
> > +	DECLARE_BITMAP(new, TOTAL_BITS);
> > +	DECLARE_BITMAP(changed, TOTAL_BITS);
> 
> -- 
> With Best Regards,
> Andy Shevchenko
> 
> 

^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [PATCH v3 3/4] gpio: thunderx: Utilize for_each_set_clump macro
  2020-04-29 10:17   ` Andy Shevchenko
@ 2020-04-30 16:22     ` Syed Nayyar Waris
  0 siblings, 0 replies; 13+ messages in thread
From: Syed Nayyar Waris @ 2020-04-30 16:22 UTC (permalink / raw)
  To: Andy Shevchenko
  Cc: akpm, vilhelm.gray, rrichter, linus.walleij, bgolaszewski,
	linux-gpio, linux-kernel

On Wed, Apr 29, 2020 at 01:17:42PM +0300, Andy Shevchenko wrote:
> On Wed, Apr 29, 2020 at 04:37:41AM +0530, Syed Nayyar Waris wrote:
> > This patch reimplements the thunderx_gpio_set_multiple function in
> > drivers/gpio/gpio-thunderx.c to use the new for_each_set_clump macro.
> > Instead of looping for each bank in thunderx_gpio_set_multiple
> > function, now we can skip bank which is not set and save cycles.
> 
> > +	const unsigned long bank_size = 64;
> 
> Shouldn't be rather definition?

Thanks. I think you mean macro definition. I will incorporate this in my
next version.

> 
> -- 
> With Best Regards,
> Andy Shevchenko
> 
> 

^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [PATCH v3 4/4] gpio: xilinx: Utilize for_each_set_clump macro
  2020-04-30 16:15     ` Syed Nayyar Waris
@ 2020-04-30 16:38       ` Andy Shevchenko
  2020-04-30 23:32         ` William Breathitt Gray
  0 siblings, 1 reply; 13+ messages in thread
From: Andy Shevchenko @ 2020-04-30 16:38 UTC (permalink / raw)
  To: Syed Nayyar Waris
  Cc: akpm, vilhelm.gray, linus.walleij, bgolaszewski, michal.simek,
	linux-gpio, linux-arm-kernel, linux-kernel

On Thu, Apr 30, 2020 at 09:45:14PM +0530, Syed Nayyar Waris wrote:
> On Wed, Apr 29, 2020 at 01:21:14PM +0300, Andy Shevchenko wrote:
> > On Wed, Apr 29, 2020 at 04:39:47AM +0530, Syed Nayyar Waris wrote:

...

> > > +	const unsigned long state_size = BITS_PER_TYPE(*state);
> > 
> > This '*state' is unneeded complication, use BITS_PER_U32.
> > 
> > > +#define TOTAL_BITS BITS_PER_TYPE(chip->gpio_state)
> > 
> > This macro makes code uglier, besides the fact of absence of #undef.
> > And also see above.
> 
> Thank you for your review comments. Just want to clarify, you want
>  a new macro to be created - 'BITS_PER_U32' ?

It's already there (read bits.h).

> Also, don't you think that with BITS_PER_TYPE(), in case later the type
> of 'state' changes, it will be reflected in this code without any code
> change?

If it changes the bits per type will be least issues there. The rationale
behind is to have code readable. In proposed change it is not.

> Let me know if I have misunderstood something.
> 
> > 
> > > +	DECLARE_BITMAP(old, TOTAL_BITS);
> > > +	DECLARE_BITMAP(new, TOTAL_BITS);
> > > +	DECLARE_BITMAP(changed, TOTAL_BITS);

-- 
With Best Regards,
Andy Shevchenko



^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [PATCH v3 4/4] gpio: xilinx: Utilize for_each_set_clump macro
  2020-04-30 16:38       ` Andy Shevchenko
@ 2020-04-30 23:32         ` William Breathitt Gray
  2020-05-01 13:32           ` Andy Shevchenko
  0 siblings, 1 reply; 13+ messages in thread
From: William Breathitt Gray @ 2020-04-30 23:32 UTC (permalink / raw)
  To: Andy Shevchenko
  Cc: Syed Nayyar Waris, akpm, linus.walleij, bgolaszewski,
	michal.simek, linux-gpio, linux-arm-kernel, linux-kernel

[-- Attachment #1: Type: text/plain, Size: 1653 bytes --]

On Thu, Apr 30, 2020 at 07:38:55PM +0300, Andy Shevchenko wrote:
> On Thu, Apr 30, 2020 at 09:45:14PM +0530, Syed Nayyar Waris wrote:
> > On Wed, Apr 29, 2020 at 01:21:14PM +0300, Andy Shevchenko wrote:
> > > On Wed, Apr 29, 2020 at 04:39:47AM +0530, Syed Nayyar Waris wrote:
> 
> ...
> 
> > > > +	const unsigned long state_size = BITS_PER_TYPE(*state);
> > > 
> > > This '*state' is unneeded complication, use BITS_PER_U32.
> > > 
> > > > +#define TOTAL_BITS BITS_PER_TYPE(chip->gpio_state)
> > > 
> > > This macro makes code uglier, besides the fact of absence of #undef.
> > > And also see above.
> > 
> > Thank you for your review comments. Just want to clarify, you want
> >  a new macro to be created - 'BITS_PER_U32' ?
> 
> It's already there (read bits.h).

I'm having trouble finding the BITS_PER_U32 macro; are you thinking of
BITS_PER_LONG? I don't think there are any cases where u32 is not 32
bits wide, so perhaps it'll be better to just hardcode 32 directly in
the code here to make it easier to read.

William Breathitt Gray

> 
> > Also, don't you think that with BITS_PER_TYPE(), in case later the type
> > of 'state' changes, it will be reflected in this code without any code
> > change?
> 
> If it changes the bits per type will be least issues there. The rationale
> behind is to have code readable. In proposed change it is not.
> 
> > Let me know if I have misunderstood something.
> > 
> > > 
> > > > +	DECLARE_BITMAP(old, TOTAL_BITS);
> > > > +	DECLARE_BITMAP(new, TOTAL_BITS);
> > > > +	DECLARE_BITMAP(changed, TOTAL_BITS);
> 
> -- 
> With Best Regards,
> Andy Shevchenko
> 
> 

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]

^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [PATCH v3 4/4] gpio: xilinx: Utilize for_each_set_clump macro
  2020-04-30 23:32         ` William Breathitt Gray
@ 2020-05-01 13:32           ` Andy Shevchenko
  0 siblings, 0 replies; 13+ messages in thread
From: Andy Shevchenko @ 2020-05-01 13:32 UTC (permalink / raw)
  To: William Breathitt Gray
  Cc: Andy Shevchenko, Syed Nayyar Waris, Andrew Morton, Linus Walleij,
	Bartosz Golaszewski, Michal Simek, open list:GPIO SUBSYSTEM,
	linux-arm Mailing List, Linux Kernel Mailing List

On Fri, May 1, 2020 at 2:38 AM William Breathitt Gray
<vilhelm.gray@gmail.com> wrote:
> On Thu, Apr 30, 2020 at 07:38:55PM +0300, Andy Shevchenko wrote:
> > On Thu, Apr 30, 2020 at 09:45:14PM +0530, Syed Nayyar Waris wrote:
> > > On Wed, Apr 29, 2020 at 01:21:14PM +0300, Andy Shevchenko wrote:
> > > > On Wed, Apr 29, 2020 at 04:39:47AM +0530, Syed Nayyar Waris wrote:
> >
> > ...
> >
> > > > > +       const unsigned long state_size = BITS_PER_TYPE(*state);
> > > >
> > > > This '*state' is unneeded complication, use BITS_PER_U32.
> > > >
> > > > > +#define TOTAL_BITS BITS_PER_TYPE(chip->gpio_state)
> > > >
> > > > This macro makes code uglier, besides the fact of absence of #undef.
> > > > And also see above.
> > >
> > > Thank you for your review comments. Just want to clarify, you want
> > >  a new macro to be created - 'BITS_PER_U32' ?
> >
> > It's already there (read bits.h).
>
> I'm having trouble finding the BITS_PER_U32 macro; are you thinking of
> BITS_PER_LONG?

Oh, my bad. I messed above with BITS_TO_U32() which is not what we want here.

> I don't think there are any cases where u32 is not 32
> bits wide, so perhaps it'll be better to just hardcode 32 directly in
> the code here to make it easier to read.

Yes, would work!

-- 
With Best Regards,
Andy Shevchenko

^ permalink raw reply	[flat|nested] 13+ messages in thread

end of thread, other threads:[~2020-05-01 13:32 UTC | newest]

Thread overview: 13+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-04-28 23:03 [PATCH v3 0/4] Introduce the for_each_set_clump macro Syed Nayyar Waris
2020-04-28 23:04 ` [PATCH v3 1/4] bitops: Introduce the " Syed Nayyar Waris
2020-04-28 23:05 ` [PATCH v3 2/4] lib/test_bitmap.c: Add for_each_set_clump test cases Syed Nayyar Waris
2020-04-29 10:16   ` Andy Shevchenko
2020-04-28 23:07 ` [PATCH v3 3/4] gpio: thunderx: Utilize for_each_set_clump macro Syed Nayyar Waris
2020-04-29 10:17   ` Andy Shevchenko
2020-04-30 16:22     ` Syed Nayyar Waris
2020-04-28 23:09 ` [PATCH v3 4/4] gpio: xilinx: " Syed Nayyar Waris
2020-04-29 10:21   ` Andy Shevchenko
2020-04-30 16:15     ` Syed Nayyar Waris
2020-04-30 16:38       ` Andy Shevchenko
2020-04-30 23:32         ` William Breathitt Gray
2020-05-01 13:32           ` Andy Shevchenko

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