Hello Linus,
Since this patchset primarily affects GPIO drivers, would you like
to pick it up through your GPIO tree?
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 v9:
- [Patch 4/4]: Remove looping of 'for_each_set_clump' and instead process two
halves of a 64-bit bitmap separately or individually. Use normal spin_lock
call for second inner lock. And take the spin_lock_init call outside the 'if'
condition in the probe function of driver.
Changes in v8:
- [Patch 2/4]: Minor change: Use '__initdata' for correct section mismatch
in 'clump_test_data' array.
Changes in v7:
- [Patch 2/4]: Minor changes: Use macro 'DECLARE_BITMAP()' and split 'struct'
definition and test data.
Changes in v6:
- [Patch 2/4]: Make 'for loop' inside test_for_each_set_clump more
succinct.
Changes in v5:
- [Patch 4/4]: Minor change: Hardcode value for better code readability.
Changes in v4:
- [Patch 2/4]: Use 'for' loop in test function of for_each_set_clump.
- [Patch 3/4]: Minor change: Inline value for better code readability.
- [Patch 4/4]: Minor change: Inline value for better code readability.
Changes in v3:
- [Patch 3/4]: Change datatype of some variables from u64 to unsigned long
in function thunderx_gpio_set_multiple.
CHanges in v2:
- [Patch 2/4]: Unify different tests for 'for_each_set_clump'. Pass test data as
function parameters.
- [Patch 2/4]: Remove unnecessary bitmap_zero calls.
Syed Nayyar Waris (4):
bitops: Introduce 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 generic bitmap_get_value and _set_value.
drivers/gpio/gpio-thunderx.c | 11 ++-
drivers/gpio/gpio-xilinx.c | 66 +++++++-------
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 | 145 ++++++++++++++++++++++++++++++
7 files changed, 292 insertions(+), 37 deletions(-)
base-commit: b3a9e3b9622ae10064826dccb4f7a52bd88c7407
--
2.26.2
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 <[email protected]>
Signed-off-by: Syed Nayyar Waris <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
Signed-off-by: William Breathitt Gray <[email protected]>
---
Changes in v9:
- No change.
Changes in v8:
- No change.
Changes in v7:
- No change.
Changes in v6:
- No change.
Changes in v5:
- No change.
Changes in v4:
- No change.
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 99f2ac30b1d9..36a445e4a7cc 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
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.
Signed-off-by: Syed Nayyar Waris <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
Signed-off-by: William Breathitt Gray <[email protected]>
---
Changes in v9:
- No change.
Changes in v8:
- [Patch 2/4]: Minor change: Use '__initdata' for correct section mismatch
in 'clump_test_data' array.
Changes in v7:
- Minor changes: Use macro 'DECLARE_BITMAP()' and split 'struct'
definition and test data.
Changes in v6:
- Make 'for loop' inside 'test_for_each_set_clump' more succinct.
Changes in v5:
- No change.
Changes in v4:
- Use 'for' loop in test function of 'for_each_set_clump'.
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 | 145 ++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 145 insertions(+)
diff --git a/lib/test_bitmap.c b/lib/test_bitmap.c
index 6b13150667f5..78c0048870a6 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)
{
@@ -577,6 +610,28 @@ static void noinline __init test_mem_optimisations(void)
}
}
+static const unsigned long clump_bitmap_data[] __initconst = {
+ 0x38000201,
+ 0x05ff0f38,
+ 0xeffedcba,
+ 0xbbbbabcd,
+ 0x000000aa,
+ 0x000000aa,
+ 0x00ff0000,
+ 0xaaaaaa00,
+ 0xff000000,
+ 0x00aa0000,
+ 0x00000000,
+ 0x00000000,
+ 0x00000000,
+ 0x0f000000,
+ 0x00ff0000,
+ 0xaaaaaa00,
+ 0xff000000,
+ 0x00aa0000,
+ 0x00000ac0,
+};
+
static const unsigned char clump_exp[] __initconst = {
0x01, /* 1 bit set */
0x02, /* non-edge 1 bit set */
@@ -588,6 +643,95 @@ 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,
+};
+
+struct clump_test_data_params {
+ DECLARE_BITMAP(data, 256);
+ unsigned long count;
+ unsigned long offset;
+ unsigned long limit;
+ unsigned long clump_size;
+ unsigned long const *exp;
+};
+
+static struct clump_test_data_params clump_test_data[] __initdata =
+ { {{0}, 2, 0, 64, 8, clump_exp1},
+ {{0}, 8, 2, 240, 24, clump_exp2},
+ {{0}, 8, 10, 240, 30, clump_exp3},
+ {{0}, 1, 18, 18, 6, clump_exp4} };
+
+static void __init prepare_test_data(unsigned int index)
+{
+ int i;
+ unsigned long width = 0;
+
+ for(i = 0; i < clump_test_data[index].count; i++)
+ {
+ bitmap_set_value(clump_test_data[index].data,
+ clump_bitmap_data[(clump_test_data[index].offset)++], width, 32);
+ width += 32;
+ }
+}
+
+static void __init execute_for_each_set_clump_test(unsigned int index)
+{
+ unsigned long start, clump;
+
+ for_each_set_clump(start, clump, clump_test_data[index].data,
+ clump_test_data[index].limit,
+ clump_test_data[index].clump_size)
+ expect_eq_clump(start, clump_test_data[index].limit, clump_test_data[index].exp,
+ &clump, clump_test_data[index].clump_size);
+}
+
+static void __init test_for_each_set_clump(void)
+{
+ unsigned int i;
+
+ for (i = 0; i < ARRAY_SIZE(clump_test_data); i++) {
+ prepare_test_data(i);
+ execute_for_each_set_clump_test(i);
+ }
+}
+
static void __init test_for_each_set_clump8(void)
{
#define CLUMP_EXP_NUMBITS 64
@@ -623,6 +767,7 @@ 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
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 <[email protected]>
Cc: Bartosz Golaszewski <[email protected]>
Signed-off-by: Syed Nayyar Waris <[email protected]>
Signed-off-by: William Breathitt Gray <[email protected]>
---
Changes in v9:
- No change.
Changes in v8:
- No change.
Changes in v7:
- No change.
Changes in v6:
- No change.
Changes in v5:
- No change.
Changes in v4:
- Minor change: Inline value '64' in code for better code readability.
Changes in v3:
- Change datatype of some variables from u64 to unsigned long
in function thunderx_gpio_set_multiple.
Changes in v2:
- No change.
drivers/gpio/gpio-thunderx.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/drivers/gpio/gpio-thunderx.c b/drivers/gpio/gpio-thunderx.c
index 9f66deab46ea..58c9bb25a377 100644
--- a/drivers/gpio/gpio-thunderx.c
+++ b/drivers/gpio/gpio-thunderx.c
@@ -275,12 +275,15 @@ 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;
+ 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, 64) {
+ bank = offset / 64;
+ 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
This patch reimplements the xgpio_set_multiple function in
drivers/gpio/gpio-xilinx.c to use the new generic functions:
bitmap_get_value and bitmap_set_value. The code is now simpler
to read and understand. Moreover, instead of looping for each bit
in xgpio_set_multiple function, now we can check each channel at
a time and save cycles.
---
Changes in v9:
- Remove looping of 'for_each_set_clump' and instead process two
halves of a 64-bit bitmap separately or individually. Use normal spin_lock
call for second inner lock. And take the spin_lock_init call outside the 'if'
condition in the 'probe' function of driver.
Changes in v8:
- No change.
Changes in v7:
- No change.
Changes in v6:
- No change.
Changes in v5:
- Minor change: Inline values '32' and '64' in code for better
code readability.
Changes in v4:
- Minor change: Inline values '32' and '64' in code for better
code readability.
Changes in v3:
- No change.
Changes in v2:
- No change
drivers/gpio/gpio-xilinx.c | 66 +++++++++++++++++++-------------------
1 file changed, 33 insertions(+), 33 deletions(-)
diff --git a/drivers/gpio/gpio-xilinx.c b/drivers/gpio/gpio-xilinx.c
index 67f9f82e0db0..48393d06fb55 100644
--- a/drivers/gpio/gpio-xilinx.c
+++ b/drivers/gpio/gpio-xilinx.c
@@ -136,39 +136,39 @@ 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 flag;
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);
- }
- }
-
- xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET +
- index * XGPIO_CHANNEL_OFFSET, chip->gpio_state[index]);
-
- spin_unlock_irqrestore(&chip->gpio_lock[index], flags);
+ u32 *const state = chip->gpio_state;
+ unsigned int *const width = chip->gpio_width;
+
+ DECLARE_BITMAP(old, 64);
+ DECLARE_BITMAP(new, 64);
+ DECLARE_BITMAP(changed, 64);
+
+ spin_lock_irqsave(&chip->gpio_lock[0], flag);
+ spin_lock(&chip->gpio_lock[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, 32);
+ bitmap_set_value(old, state[1], 32, 32);
+ 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, 32);
+ bitmap_set_value(new, state[1], 32, 32);
+ bitmap_xor(changed, old, new, 64);
+
+ if (((u32 *)changed)[0])
+ xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET,
+ state[0]);
+ if (((u32 *)changed)[1])
+ xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET +
+ XGPIO_CHANNEL_OFFSET, state[1]);
+
+ spin_unlock(&chip->gpio_lock[1]);
+ spin_unlock_irqrestore(&chip->gpio_lock[0], flag);
}
/**
@@ -292,6 +292,7 @@ static int xgpio_probe(struct platform_device *pdev)
chip->gpio_width[0] = 32;
spin_lock_init(&chip->gpio_lock[0]);
+ spin_lock_init(&chip->gpio_lock[1]);
if (of_property_read_u32(np, "xlnx,is-dual", &is_dual))
is_dual = 0;
@@ -314,7 +315,6 @@ static int xgpio_probe(struct platform_device *pdev)
&chip->gpio_width[1]))
chip->gpio_width[1] = 32;
- spin_lock_init(&chip->gpio_lock[1]);
}
chip->gc.base = -1;
--
2.26.2
On Sat, Jun 27, 2020 at 01:44:23PM +0530, Syed Nayyar Waris wrote:
> This patch reimplements the xgpio_set_multiple function in
> drivers/gpio/gpio-xilinx.c to use the new generic functions:
> bitmap_get_value and bitmap_set_value. The code is now simpler
> to read and understand. Moreover, instead of looping for each bit
> in xgpio_set_multiple function, now we can check each channel at
> a time and save cycles.
> ---
> Changes in v9:
> - Remove looping of 'for_each_set_clump' and instead process two
> halves of a 64-bit bitmap separately or individually. Use normal spin_lock
> call for second inner lock. And take the spin_lock_init call outside the 'if'
> condition in the 'probe' function of driver.
>
> Changes in v8:
> - No change.
>
> Changes in v7:
> - No change.
>
> Changes in v6:
> - No change.
>
> Changes in v5:
> - Minor change: Inline values '32' and '64' in code for better
> code readability.
>
> Changes in v4:
> - Minor change: Inline values '32' and '64' in code for better
> code readability.
>
> Changes in v3:
> - No change.
>
> Changes in v2:
> - No change
>
> drivers/gpio/gpio-xilinx.c | 66 +++++++++++++++++++-------------------
> 1 file changed, 33 insertions(+), 33 deletions(-)
>
> diff --git a/drivers/gpio/gpio-xilinx.c b/drivers/gpio/gpio-xilinx.c
> index 67f9f82e0db0..48393d06fb55 100644
> --- a/drivers/gpio/gpio-xilinx.c
> +++ b/drivers/gpio/gpio-xilinx.c
> @@ -136,39 +136,39 @@ 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 flag;
Hi Syed,
I have a couple minor suggestions in case you submit a version 10. Leave
this variable named "flags" because it refers to CPU flags which will
likely be more than one flag anyway.
> @@ -292,6 +292,7 @@ static int xgpio_probe(struct platform_device *pdev)
> chip->gpio_width[0] = 32;
>
> spin_lock_init(&chip->gpio_lock[0]);
> + spin_lock_init(&chip->gpio_lock[1]);
>
> if (of_property_read_u32(np, "xlnx,is-dual", &is_dual))
> is_dual = 0;
> @@ -314,7 +315,6 @@ static int xgpio_probe(struct platform_device *pdev)
> &chip->gpio_width[1]))
> chip->gpio_width[1] = 32;
>
Remove this whitespace as well.
Thanks,
William Breathitt Gray
> - spin_lock_init(&chip->gpio_lock[1]);
> }
>
> chip->gc.base = -1;
> --
> 2.26.2
>
On Sat, Jun 27, 2020 at 1:40 PM Syed Nayyar Waris <[email protected]> wrote:
>
> Hello Linus,
>
> Since this patchset primarily affects GPIO drivers, would you like
> to pick it up through your GPIO tree?
>
> 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 v9:
> - [Patch 4/4]: Remove looping of 'for_each_set_clump' and instead process two
> halves of a 64-bit bitmap separately or individually. Use normal spin_lock
> call for second inner lock. And take the spin_lock_init call outside the 'if'
> condition in the probe function of driver.
>
> Changes in v8:
> - [Patch 2/4]: Minor change: Use '__initdata' for correct section mismatch
> in 'clump_test_data' array.
>
> Changes in v7:
> - [Patch 2/4]: Minor changes: Use macro 'DECLARE_BITMAP()' and split 'struct'
> definition and test data.
>
> Changes in v6:
> - [Patch 2/4]: Make 'for loop' inside test_for_each_set_clump more
> succinct.
>
> Changes in v5:
> - [Patch 4/4]: Minor change: Hardcode value for better code readability.
>
> Changes in v4:
> - [Patch 2/4]: Use 'for' loop in test function of for_each_set_clump.
> - [Patch 3/4]: Minor change: Inline value for better code readability.
> - [Patch 4/4]: Minor change: Inline value for better code readability.
>
> Changes in v3:
> - [Patch 3/4]: Change datatype of some variables from u64 to unsigned long
> in function thunderx_gpio_set_multiple.
>
> CHanges in v2:
> - [Patch 2/4]: Unify different tests for 'for_each_set_clump'. Pass test data as
> function parameters.
> - [Patch 2/4]: Remove unnecessary bitmap_zero calls.
>
> Syed Nayyar Waris (4):
> bitops: Introduce 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 generic bitmap_get_value and _set_value.
>
> drivers/gpio/gpio-thunderx.c | 11 ++-
> drivers/gpio/gpio-xilinx.c | 66 +++++++-------
> 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 | 145 ++++++++++++++++++++++++++++++
> 7 files changed, 292 insertions(+), 37 deletions(-)
>
>
> base-commit: b3a9e3b9622ae10064826dccb4f7a52bd88c7407
> --
> 2.26.2
>
Hi Andrew, Linus
What do you think about this patchset on 'for_each_set_clump' ?
if there's anything else you think that should be changed in this, or if this
version looks good to you to pick up, kindly, let me know.
Regards
Syed Nayyar Waris
Hi Syed,
sorry for taking so long. I was on vacation and a bit snowed
under by work.
On Sat, Jun 27, 2020 at 10:10 AM Syed Nayyar Waris <[email protected]> wrote:
> Since this patchset primarily affects GPIO drivers, would you like
> to pick it up through your GPIO tree?
I have applied the patches to an immutable branch and pushed
to kernelorg for testing (autobuilders will play with it I hope).
If all works fine I will merge this into my devel branch for v5.9.
It would be desirable if Andrew gave his explicit ACK on it too.
Yours,
Linus Walleij
On Thu, Jul 16, 2020 at 6:19 PM Linus Walleij <[email protected]> wrote:
>
> Hi Syed,
>
> sorry for taking so long. I was on vacation and a bit snowed
> under by work.
>
> On Sat, Jun 27, 2020 at 10:10 AM Syed Nayyar Waris <[email protected]> wrote:
>
> > Since this patchset primarily affects GPIO drivers, would you like
> > to pick it up through your GPIO tree?
>
> I have applied the patches to an immutable branch and pushed
> to kernelorg for testing (autobuilders will play with it I hope).
>
> If all works fine I will merge this into my devel branch for v5.9.
>
> It would be desirable if Andrew gave his explicit ACK on it too.
>
> Yours,
> Linus Walleij
Hi Linus,
As a reminder, I would like to point out about the
'for_each_set_clump' patchset. If it's alright and if anything is
needed to take it further so that it is finally accepted.
Regards
Syed Nayyar Waris
On Thu, Jul 16, 2020 at 02:49:35PM +0200, Linus Walleij wrote:
> Hi Syed,
>
> sorry for taking so long. I was on vacation and a bit snowed
> under by work.
>
> On Sat, Jun 27, 2020 at 10:10 AM Syed Nayyar Waris <[email protected]> wrote:
>
> > Since this patchset primarily affects GPIO drivers, would you like
> > to pick it up through your GPIO tree?
>
> I have applied the patches to an immutable branch and pushed
> to kernelorg for testing (autobuilders will play with it I hope).
>
> If all works fine I will merge this into my devel branch for v5.9.
>
> It would be desirable if Andrew gave his explicit ACK on it too.
>
> Yours,
> Linus Walleij
Hi Linus,
What's the name of the branch with these patches on kernelorg; I'm
having trouble finding it?
Btw, I'm CCing Andrew as well here because I notice him missing from the
CC list earlier for this patchset.
Thanks,
William Breathitt Gray
On Sat, Sep 12, 2020 at 12:54 AM William Breathitt Gray
<[email protected]> wrote:
> On Thu, Jul 16, 2020 at 02:49:35PM +0200, Linus Walleij wrote:
> > Hi Syed,
> >
> > sorry for taking so long. I was on vacation and a bit snowed
> > under by work.
> >
> > On Sat, Jun 27, 2020 at 10:10 AM Syed Nayyar Waris <[email protected]> wrote:
> >
> > > Since this patchset primarily affects GPIO drivers, would you like
> > > to pick it up through your GPIO tree?
> >
> > I have applied the patches to an immutable branch and pushed
> > to kernelorg for testing (autobuilders will play with it I hope).
> >
> > If all works fine I will merge this into my devel branch for v5.9.
> >
> > It would be desirable if Andrew gave his explicit ACK on it too.
> >
> > Yours,
> > Linus Walleij
>
> Hi Linus,
>
> What's the name of the branch with these patches on kernelorg; I'm
> having trouble finding it?
>
> Btw, I'm CCing Andrew as well here because I notice him missing from the
> CC list earlier for this patchset.
IIRC there were complaints from the zeroday build robot so I
dropped the branch and I am still waiting for a fixed up patch
series.
Yours,
Linus Walleij
On Tue, Sep 29, 2020 at 02:45:18PM +0200, Linus Walleij wrote:
> On Sat, Sep 12, 2020 at 12:54 AM William Breathitt Gray
> <[email protected]> wrote:
> > On Thu, Jul 16, 2020 at 02:49:35PM +0200, Linus Walleij wrote:
> > > Hi Syed,
> > >
> > > sorry for taking so long. I was on vacation and a bit snowed
> > > under by work.
> > >
> > > On Sat, Jun 27, 2020 at 10:10 AM Syed Nayyar Waris <[email protected]> wrote:
> > >
> > > > Since this patchset primarily affects GPIO drivers, would you like
> > > > to pick it up through your GPIO tree?
> > >
> > > I have applied the patches to an immutable branch and pushed
> > > to kernelorg for testing (autobuilders will play with it I hope).
> > >
> > > If all works fine I will merge this into my devel branch for v5.9.
> > >
> > > It would be desirable if Andrew gave his explicit ACK on it too.
> > >
> > > Yours,
> > > Linus Walleij
> >
> > Hi Linus,
> >
> > What's the name of the branch with these patches on kernelorg; I'm
> > having trouble finding it?
> >
> > Btw, I'm CCing Andrew as well here because I notice him missing from the
> > CC list earlier for this patchset.
>
> IIRC there were complaints from the zeroday build robot so I
> dropped the branch and I am still waiting for a fixed up patch
> series.
>
> Yours,
> Linus Walleij
My apologies, I wasn't aware a build error was reported. I'll be happy
to help address the issue with Syed, but I can't seem to find a copy of
the message on <https://lkml.org/lkml/2020/6/27/107> or my email logs.
Do you have a link available to the zeroday build log?
Thanks,
William Breathitt Gray
On Tue, Sep 29, 2020 at 4:09 PM William Breathitt Gray
<[email protected]> wrote:
>
> On Tue, Sep 29, 2020 at 02:45:18PM +0200, Linus Walleij wrote:
> > On Sat, Sep 12, 2020 at 12:54 AM William Breathitt Gray
> > <[email protected]> wrote:
> > > On Thu, Jul 16, 2020 at 02:49:35PM +0200, Linus Walleij wrote:
> > > > On Sat, Jun 27, 2020 at 10:10 AM Syed Nayyar Waris <[email protected]> wrote:
...
> > > What's the name of the branch with these patches on kernelorg; I'm
> > > having trouble finding it?
> > >
> > > Btw, I'm CCing Andrew as well here because I notice him missing from the
> > > CC list earlier for this patchset.
> >
> > IIRC there were complaints from the zeroday build robot so I
> > dropped the branch and I am still waiting for a fixed up patch
> > series.
> My apologies, I wasn't aware a build error was reported. I'll be happy
> to help address the issue with Syed, but I can't seem to find a copy of
> the message on <https://lkml.org/lkml/2020/6/27/107> or my email logs.
> Do you have a link available to the zeroday build log?
Time to open lore.kernel.org? [1][2]
Linus, are you referencing to [3]? It was fixed in GENMASK()
implementation some time ago.
[1]: https://lore.kernel.org/lkml/[email protected]/
[2]: https://lore.kernel.org/lkml/[email protected]/
[3]: https://lore.kernel.org/lkml/202006171559.JSbGJXNw%[email protected]/
--
With Best Regards,
Andy Shevchenko
On Tue, Sep 29, 2020 at 3:14 PM Andy Shevchenko
<[email protected]> wrote:
> Linus, are you referencing to [3]? It was fixed in GENMASK()
> implementation some time ago.
> [3]: https://lore.kernel.org/lkml/202006171559.JSbGJXNw%[email protected]/
Yup.
I tried to apply the patches again now to test it but now patch 2
needs to be rebased.
Sorry for all the trouble!
Syed can you rebase the patch set on v5.9-rc1 and resend as v10?
Yours,
Linus Walleij
On Wed, Sep 30, 2020 at 2:59 PM Linus Walleij <[email protected]> wrote:
>
> On Tue, Sep 29, 2020 at 3:14 PM Andy Shevchenko
> <[email protected]> wrote:
>
> > Linus, are you referencing to [3]? It was fixed in GENMASK()
> > implementation some time ago.
> > [3]: https://lore.kernel.org/lkml/202006171559.JSbGJXNw%[email protected]/
>
> Yup.
>
> I tried to apply the patches again now to test it but now patch 2
> needs to be rebased.
>
> Sorry for all the trouble!
>
> Syed can you rebase the patch set on v5.9-rc1 and resend as v10?
Sure Linus. I will send it as soon as possible.
Thanks
Syed Nayyar Waris