Re: [PATCH v8 4/4] gpio: xilinx: Utilize for_each_set_clump macro
On 2020-06-15 13:54, 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.
Cc: Bartosz Golaszewski
Cc: Michal Simek
Signed-off-by: Syed Nayyar Waris
Signed-off-by: William Breathitt Gray
---
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 | 62 --
1 file changed, 32 insertions(+), 30 deletions(-)
diff --git a/drivers/gpio/gpio-xilinx.c b/drivers/gpio/gpio-xilinx.c
index 67f9f82e0db0..e81092dea27e 100644
--- a/drivers/gpio/gpio-xilinx.c
+++ b/drivers/gpio/gpio-xilinx.c
@@ -136,39 +136,41 @@ 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;
Immutable pointers to mutable data are pretty unusual, especially for
temporary local variables. Let me share my thought process upon seeing this:
- hmm, is "* const" simply a mistake that's meant to be "const *"?
- no, updating chip->gpio_state seems
appropriate, so it can't be that.
- does anything take the address of either of these variables that might
justify it?
- nope, they're only ever used by
value
- hmm, maybe it's just paranoia, but in that case why isn't width "const
* const" since chip->gpio_width shouldn't need to be modified?
- hmm...
And at that point I've spent nearly a minute parsing what should have
been be some trivial definitions of local shorthand variables. Defensive
programming is all very well, but the distraction to readers (I can't be
the only one) can easily outweigh any perceived value in trying to
harden against theoretical future developer error in a straightforward
~30-line function.
+ unsigned long offset, clump;
+ size_t index;
+
+ DECLARE_BITMAP(old, 64);
+ DECLARE_BITMAP(new, 64);
+ DECLARE_BITMAP(changed, 64);
+
+ spin_lock_irqsave(&chip->gpio_lock[0], flags[0]);
+ spin_lock_irqsave(&chip->gpio_lock[1], flags[1]);
Why _irqsave on the inner lock? (think about it...)
+
+ 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);
+
+ for_each_set_clump(offset, clump, changed, 64, 32) {
+ index = offset / 32;
+ xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET +
+ index * XGPIO_CHANNEL_OFFSET,
+ state[index]);
}
TBH this looks like a rather overcomplicated and horribly inefficient
way of doing:
if (((u32 *)changed)[0])
xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET,
Re: [PATCH v8 4/4] gpio: xilinx: Utilize for_each_set_clump macro
On Tue, Jun 16, 2020 at 11:27:18AM +0530, Syed Nayyar Waris wrote: Hi, > Regarding the compilation warning reported above: > > "sparse: shift too big (64) for type unsigned long" at line 639 > "sparse: invalid access past the end of 'old' (8 8)" at line 638 > > Kindly refer to the code above, at these line numbers. > > I am in the process of fixing this warning. But what would be the fix? > ? At the moment can't think of a code-fix to make the compilation > warning disappear (specially at line 639). Can anyone please explain > to me the meaning of the compilation warning more deeply? This error message is caused by sparse doing the check too early. There is thus nothing to be fixed for it in this code. Best regards, -- Luc
Re: [PATCH v8 4/4] gpio: xilinx: Utilize for_each_set_clump macro
On Fri, Jun 19, 2020 at 11:38:59AM +0300, Andy Shevchenko wrote: > On Fri, Jun 19, 2020 at 10:02 AM Syed Nayyar Waris > wrote: > > ... > > > > config: sparc64-randconfig-s032-20200615 (attached as .config) > > > compiler: sparc64-linux-gcc (GCC) 9.3.0 > > > reproduce: > > > # apt-get install sparse > > > # sparse version: v0.6.2-rc1-3-g55607964-dirty > > > # save the attached .config to linux build tree > > > make W=1 C=1 ARCH=sparc64 CF='-fdiagnostic-prefix > > > -D__CHECK_ENDIAN__' > > ... > > > > sparse warnings: (new ones prefixed by >>) > > > > > > >> include/linux/bitmap.h:639:45: sparse: sparse: shift too big (64) for > > > >> type unsigned long > > > >> include/linux/bitmap.h:639:45: sparse: sparse: shift too big (64) for > > > >> type unsigned long > > >include/linux/bitmap.h:594:63: sparse: sparse: shift too big (64) for > > > type unsigned long > > > >> include/linux/bitmap.h:639:45: sparse: sparse: shift too big (64) for > > > >> type unsigned long > > > >> include/linux/bitmap.h:638:17: sparse: sparse: invalid access past the > > > >> end of 'old' (8 8) > > > It seems to me that to reproduce this warning, I have to use the > > sparc64 compiler. I have installed 'sparc64-linux-gnu-gcc' on my > > computer. > > Sparse is not a compiler. On x86_64: CHECK drivers/gpio/gpio-xilinx.c include/linux/bitmap.h:639:45: warning: shift too big (64) for type unsigned long include/linux/bitmap.h:639:45: warning: shift too big (64) for type unsigned long include/linux/bitmap.h:594:63: warning: shift too big (64) for type unsigned long include/linux/bitmap.h:639:45: warning: shift too big (64) for type unsigned long include/linux/bitmap.h:638:17: warning: invalid access past the end of 'old' (8 8) > > I have to specify that this compiler needs to be used for build > > process. How/ Where do I specify this? > > > > I have downloaded the config.gz (has config file) and placed it at the > > root of the linux kernel project tree. But the Makefile STILL has > > 'gcc' as the compiler. When I build, it is the 'gcc' compiler being > > used and not 'sparc64-linux-gnu-gcc'. I know I can manually change the > > Makefile to use sparc64 compiler, but I think there must be some more > > elegant way to do this, perhaps using make menuconfig? > > If you wish to run a compilation, download a compiler from [1], and, > after adding its bin/ folder to PATH, run > make CROSS_COMPILE=sparc64-linux- ARCH=sparc64 ... # first generate .config > > > Kindly illuminate as to how shall I reproduce the compiler warning. > > > > 803024b6c8a375 Syed Nayyar Waris 2020-06-15 @638 map[index > > > + 1] &= ~BITMAP_LAST_WORD_MASK(start + nbits); > > > 803024b6c8a375 Syed Nayyar Waris 2020-06-15 @639 map[index > > > + 1] |= (value >> space); > > Hmm... I think I sent a reply [2] where I explained how space can be > 64. Do you agree with analysis? > > [1]: https://mirrors.edge.kernel.org/pub/tools/crosstool/ > [2]: https://lore.kernel.org/lkml/20200616081428.gp2428...@smile.fi.intel.com/ -- With Best Regards, Andy Shevchenko
Re: [PATCH v8 4/4] gpio: xilinx: Utilize for_each_set_clump macro
On Fri, Jun 19, 2020 at 10:02 AM Syed Nayyar Waris wrote: ... > > config: sparc64-randconfig-s032-20200615 (attached as .config) > > compiler: sparc64-linux-gcc (GCC) 9.3.0 > > reproduce: > > # apt-get install sparse > > # sparse version: v0.6.2-rc1-3-g55607964-dirty > > # save the attached .config to linux build tree > > make W=1 C=1 ARCH=sparc64 CF='-fdiagnostic-prefix > > -D__CHECK_ENDIAN__' ... > > sparse warnings: (new ones prefixed by >>) > > > > >> include/linux/bitmap.h:639:45: sparse: sparse: shift too big (64) for > > >> type unsigned long > > >> include/linux/bitmap.h:639:45: sparse: sparse: shift too big (64) for > > >> type unsigned long > >include/linux/bitmap.h:594:63: sparse: sparse: shift too big (64) for > > type unsigned long > > >> include/linux/bitmap.h:639:45: sparse: sparse: shift too big (64) for > > >> type unsigned long > > >> include/linux/bitmap.h:638:17: sparse: sparse: invalid access past the > > >> end of 'old' (8 8) > It seems to me that to reproduce this warning, I have to use the > sparc64 compiler. I have installed 'sparc64-linux-gnu-gcc' on my > computer. Sparse is not a compiler. > I have to specify that this compiler needs to be used for build > process. How/ Where do I specify this? > > I have downloaded the config.gz (has config file) and placed it at the > root of the linux kernel project tree. But the Makefile STILL has > 'gcc' as the compiler. When I build, it is the 'gcc' compiler being > used and not 'sparc64-linux-gnu-gcc'. I know I can manually change the > Makefile to use sparc64 compiler, but I think there must be some more > elegant way to do this, perhaps using make menuconfig? If you wish to run a compilation, download a compiler from [1], and, after adding its bin/ folder to PATH, run make CROSS_COMPILE=sparc64-linux- ARCH=sparc64 ... # first generate .config > Kindly illuminate as to how shall I reproduce the compiler warning. > > 803024b6c8a375 Syed Nayyar Waris 2020-06-15 @638 map[index + > > 1] &= ~BITMAP_LAST_WORD_MASK(start + nbits); > > 803024b6c8a375 Syed Nayyar Waris 2020-06-15 @639 map[index + > > 1] |= (value >> space); Hmm... I think I sent a reply [2] where I explained how space can be 64. Do you agree with analysis? [1]: https://mirrors.edge.kernel.org/pub/tools/crosstool/ [2]: https://lore.kernel.org/lkml/20200616081428.gp2428...@smile.fi.intel.com/ -- With Best Regards, Andy Shevchenko
Re: [PATCH v8 4/4] gpio: xilinx: Utilize for_each_set_clump macro
>
> Hi Syed,
>
> Thank you for the patch! Perhaps something to improve:
>
> [auto build test WARNING on 444fc5cde64330661bf59944c43844e7d4c2ccd8]
>
> url:
> https://github.com/0day-ci/linux/commits/Syed-Nayyar-Waris/Introduce-the-for_each_set_clump-macro/20200615-205729
> base:444fc5cde64330661bf59944c43844e7d4c2ccd8
> config: sparc64-randconfig-s032-20200615 (attached as .config)
> compiler: sparc64-linux-gcc (GCC) 9.3.0
> reproduce:
> # apt-get install sparse
> # sparse version: v0.6.2-rc1-3-g55607964-dirty
> # save the attached .config to linux build tree
> make W=1 C=1 ARCH=sparc64 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__'
>
>
>
> sparse warnings: (new ones prefixed by >>)
>
> >> include/linux/bitmap.h:639:45: sparse: sparse: shift too big (64) for type
> >> unsigned long
> >> include/linux/bitmap.h:639:45: sparse: sparse: shift too big (64) for type
> >> unsigned long
>include/linux/bitmap.h:594:63: sparse: sparse: shift too big (64) for type
> unsigned long
> >> include/linux/bitmap.h:639:45: sparse: sparse: shift too big (64) for type
> >> unsigned long
> >> include/linux/bitmap.h:638:17: sparse: sparse: invalid access past the end
> >> of 'old' (8 8)
>
Hi All,
It seems to me that to reproduce this warning, I have to use the
sparc64 compiler. I have installed 'sparc64-linux-gnu-gcc' on my
computer.
I have to specify that this compiler needs to be used for build
process. How/ Where do I specify this?
I have downloaded the config.gz (has config file) and placed it at the
root of the linux kernel project tree. But the Makefile STILL has
'gcc' as the compiler. When I build, it is the 'gcc' compiler being
used and not 'sparc64-linux-gnu-gcc'. I know I can manually change the
Makefile to use sparc64 compiler, but I think there must be some more
elegant way to do this, perhaps using make menuconfig?
Kindly illuminate as to how shall I reproduce the compiler warning.
Regards
Syed Nayyar Waris
> vim +639 include/linux/bitmap.h
>
> 169c474fb22d8a William Breathitt Gray 2019-12-04 613
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 614 /**
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 615 * bitmap_set_value -
> set n-bit value within a memory region
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 616 * @map: address to
> the bitmap memory region
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 617 * @value: value of
> nbits
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 618 * @start: bit offset
> of the n-bit value
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 619 * @nbits: size of
> value in bits
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 620 */
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 621 static inline void
> bitmap_set_value(unsigned long *map,
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 622
> unsigned long value,
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 623
> unsigned long start, unsigned long nbits)
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 624 {
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 625 const size_t index =
> BIT_WORD(start);
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 626 const unsigned long
> offset = start % BITS_PER_LONG;
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 627 const unsigned long
> ceiling = roundup(start + 1, BITS_PER_LONG);
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 628 const unsigned long
> space = ceiling - start;
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 629
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 630 value &=
> GENMASK(nbits - 1, 0);
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 631
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 632 if (space >= nbits) {
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 633 map[index] &=
> ~(GENMASK(nbits + offset - 1, offset));
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 634 map[index] |=
> value << offset;
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 635 } else {
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 636 map[index] &=
> ~BITMAP_FIRST_WORD_MASK(start);
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 637 map[index] |=
> value << offset;
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 @638 map[index +
> 1] &= ~BITMAP_LAST_WORD_MASK(start + nbits);
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 @639 map[index +
> 1] |= (value >> space);
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 640 }
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 641 }
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 642
>
> :: The code at line 639 was first introduced by commit
> :: 803024b6c8a375ba9e9e9467595d7d52d4f6a38e bitops: Introduce the
> for_each_set_clump macro
>
> :: TO: Syed Nayyar Waris
Re: [PATCH v8 4/4] gpio: xilinx: Utilize for_each_set_clump macro
On Tue, Jun 16, 2020 at 1:39 AM kernel test robot wrote:
>
> Hi Syed,
>
> Thank you for the patch! Perhaps something to improve:
>
> [auto build test WARNING on 444fc5cde64330661bf59944c43844e7d4c2ccd8]
>
> url:
> https://github.com/0day-ci/linux/commits/Syed-Nayyar-Waris/Introduce-the-for_each_set_clump-macro/20200615-205729
> base:444fc5cde64330661bf59944c43844e7d4c2ccd8
> config: sparc64-randconfig-s032-20200615 (attached as .config)
> compiler: sparc64-linux-gcc (GCC) 9.3.0
> reproduce:
> # apt-get install sparse
> # sparse version: v0.6.2-rc1-3-g55607964-dirty
> # save the attached .config to linux build tree
> make W=1 C=1 ARCH=sparc64 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__'
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot
>
>
> sparse warnings: (new ones prefixed by >>)
>
> >> include/linux/bitmap.h:639:45: sparse: sparse: shift too big (64) for type
> >> unsigned long
> >> include/linux/bitmap.h:639:45: sparse: sparse: shift too big (64) for type
> >> unsigned long
>include/linux/bitmap.h:594:63: sparse: sparse: shift too big (64) for type
> unsigned long
> >> include/linux/bitmap.h:639:45: sparse: sparse: shift too big (64) for type
> >> unsigned long
> >> include/linux/bitmap.h:638:17: sparse: sparse: invalid access past the end
> >> of 'old' (8 8)
>
> vim +639 include/linux/bitmap.h
>
> 169c474fb22d8a William Breathitt Gray 2019-12-04 613
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 614 /**
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 615 * bitmap_set_value -
> set n-bit value within a memory region
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 616 * @map: address to
> the bitmap memory region
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 617 * @value: value of
> nbits
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 618 * @start: bit offset
> of the n-bit value
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 619 * @nbits: size of
> value in bits
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 620 */
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 621 static inline void
> bitmap_set_value(unsigned long *map,
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 622
> unsigned long value,
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 623
> unsigned long start, unsigned long nbits)
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 624 {
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 625 const size_t index =
> BIT_WORD(start);
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 626 const unsigned long
> offset = start % BITS_PER_LONG;
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 627 const unsigned long
> ceiling = roundup(start + 1, BITS_PER_LONG);
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 628 const unsigned long
> space = ceiling - start;
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 629
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 630 value &=
> GENMASK(nbits - 1, 0);
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 631
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 632 if (space >= nbits) {
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 633 map[index] &=
> ~(GENMASK(nbits + offset - 1, offset));
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 634 map[index] |=
> value << offset;
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 635 } else {
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 636 map[index] &=
> ~BITMAP_FIRST_WORD_MASK(start);
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 637 map[index] |=
> value << offset;
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 @638 map[index +
> 1] &= ~BITMAP_LAST_WORD_MASK(start + nbits);
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 @639 map[index +
> 1] |= (value >> space);
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 640 }
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 641 }
> 803024b6c8a375 Syed Nayyar Waris 2020-06-15 642
Regarding the compilation warning reported above:
"sparse: shift too big (64) for type unsigned long" at line 639
"sparse: invalid access past the end of 'old' (8 8)" at line 638
Kindly refer to the code above, at these line numbers.
I am in the process of fixing this warning. But what would be the fix
? At the moment can't think of a code-fix to make the compilation
warning disappear (specially at line 639). Can anyone please explain
to me the meaning of the compilation warning more deeply?
By the way, this warning was not reported in (earlier) v7 of the patchset.
Regards
Syed Nayyar Waris
Re: [PATCH v8 4/4] gpio: xilinx: Utilize for_each_set_clump macro
Hi Syed,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on 444fc5cde64330661bf59944c43844e7d4c2ccd8]
url:
https://github.com/0day-ci/linux/commits/Syed-Nayyar-Waris/Introduce-the-for_each_set_clump-macro/20200615-205729
base:444fc5cde64330661bf59944c43844e7d4c2ccd8
config: sparc64-randconfig-s032-20200615 (attached as .config)
compiler: sparc64-linux-gcc (GCC) 9.3.0
reproduce:
# apt-get install sparse
# sparse version: v0.6.2-rc1-3-g55607964-dirty
# save the attached .config to linux build tree
make W=1 C=1 ARCH=sparc64 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__'
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot
sparse warnings: (new ones prefixed by >>)
>> include/linux/bitmap.h:639:45: sparse: sparse: shift too big (64) for type
>> unsigned long
>> include/linux/bitmap.h:639:45: sparse: sparse: shift too big (64) for type
>> unsigned long
include/linux/bitmap.h:594:63: sparse: sparse: shift too big (64) for type
unsigned long
>> include/linux/bitmap.h:639:45: sparse: sparse: shift too big (64) for type
>> unsigned long
>> include/linux/bitmap.h:638:17: sparse: sparse: invalid access past the end
>> of 'old' (8 8)
vim +639 include/linux/bitmap.h
169c474fb22d8a William Breathitt Gray 2019-12-04 613
803024b6c8a375 Syed Nayyar Waris 2020-06-15 614 /**
803024b6c8a375 Syed Nayyar Waris 2020-06-15 615 * bitmap_set_value -
set n-bit value within a memory region
803024b6c8a375 Syed Nayyar Waris 2020-06-15 616 * @map: address to the
bitmap memory region
803024b6c8a375 Syed Nayyar Waris 2020-06-15 617 * @value: value of nbits
803024b6c8a375 Syed Nayyar Waris 2020-06-15 618 * @start: bit offset of
the n-bit value
803024b6c8a375 Syed Nayyar Waris 2020-06-15 619 * @nbits: size of value
in bits
803024b6c8a375 Syed Nayyar Waris 2020-06-15 620 */
803024b6c8a375 Syed Nayyar Waris 2020-06-15 621 static inline void
bitmap_set_value(unsigned long *map,
803024b6c8a375 Syed Nayyar Waris 2020-06-15 622
unsigned long value,
803024b6c8a375 Syed Nayyar Waris 2020-06-15 623
unsigned long start, unsigned long nbits)
803024b6c8a375 Syed Nayyar Waris 2020-06-15 624 {
803024b6c8a375 Syed Nayyar Waris 2020-06-15 625 const size_t index =
BIT_WORD(start);
803024b6c8a375 Syed Nayyar Waris 2020-06-15 626 const unsigned long
offset = start % BITS_PER_LONG;
803024b6c8a375 Syed Nayyar Waris 2020-06-15 627 const unsigned long
ceiling = roundup(start + 1, BITS_PER_LONG);
803024b6c8a375 Syed Nayyar Waris 2020-06-15 628 const unsigned long
space = ceiling - start;
803024b6c8a375 Syed Nayyar Waris 2020-06-15 629
803024b6c8a375 Syed Nayyar Waris 2020-06-15 630 value &= GENMASK(nbits
- 1, 0);
803024b6c8a375 Syed Nayyar Waris 2020-06-15 631
803024b6c8a375 Syed Nayyar Waris 2020-06-15 632 if (space >= nbits) {
803024b6c8a375 Syed Nayyar Waris 2020-06-15 633 map[index] &=
~(GENMASK(nbits + offset - 1, offset));
803024b6c8a375 Syed Nayyar Waris 2020-06-15 634 map[index] |=
value << offset;
803024b6c8a375 Syed Nayyar Waris 2020-06-15 635 } else {
803024b6c8a375 Syed Nayyar Waris 2020-06-15 636 map[index] &=
~BITMAP_FIRST_WORD_MASK(start);
803024b6c8a375 Syed Nayyar Waris 2020-06-15 637 map[index] |=
value << offset;
803024b6c8a375 Syed Nayyar Waris 2020-06-15 @638 map[index + 1]
&= ~BITMAP_LAST_WORD_MASK(start + nbits);
803024b6c8a375 Syed Nayyar Waris 2020-06-15 @639 map[index + 1]
|= (value >> space);
803024b6c8a375 Syed Nayyar Waris 2020-06-15 640 }
803024b6c8a375 Syed Nayyar Waris 2020-06-15 641 }
803024b6c8a375 Syed Nayyar Waris 2020-06-15 642
:: The code at line 639 was first introduced by commit
:: 803024b6c8a375ba9e9e9467595d7d52d4f6a38e bitops: Introduce the
for_each_set_clump macro
:: TO: Syed Nayyar Waris
:: CC: 0day robot
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-...@lists.01.org
.config.gz
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