[v5] bits: Fixed-type GENMASK()/BIT()

[PATCH v5 7/7] test_bits: add tests for BIT_U*()

Posted by Vincent Mailhol via B4 Relay 11 months, 1 week ago

From: Vincent Mailhol <mailhol.vincent@wanadoo.fr>

Add some additional tests in lib/test_bits.c to cover the expected
results of the fixed type BIT_U*() macros.

Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
---
Changelog

  v4 -> v5:

    - BIT_U8()/BIT_U16() are now back to u8/u16.

  v3 -> v4:

    - New patch.
---
 lib/test_bits.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/lib/test_bits.c b/lib/test_bits.c
index 91968227687bb11b7d1361b153c27eb851c6c1c2..72984fae7b815031bb6eb2892c772ffcc409cf78 100644
--- a/lib/test_bits.c
+++ b/lib/test_bits.c
@@ -9,6 +9,16 @@
 
 #define assert_type(t, x) _Generic(x, t: x, default: 0)
 
+static_assert(assert_type(u8, BIT_U8(0)) == 1u);
+static_assert(assert_type(u16, BIT_U16(0)) == 1u);
+static_assert(assert_type(u32, BIT_U32(0)) == 1u);
+static_assert(assert_type(u64, BIT_U64(0)) == 1ull);
+
+static_assert(assert_type(u8, BIT_U8(7)) == 0x80u);
+static_assert(assert_type(u16, BIT_U16(15)) == 0x8000u);
+static_assert(assert_type(u32, BIT_U32(31)) == 0x80000000u);
+static_assert(assert_type(u64, BIT_U64(63)) == 0x8000000000000000ull);
+
 static_assert(assert_type(unsigned long, GENMASK(31, 0)) == U32_MAX);
 static_assert(assert_type(unsigned long long, GENMASK_ULL(63, 0)) == U64_MAX);
 static_assert(assert_type(u8, GENMASK_U8(7, 0)) == U8_MAX);

-- 
2.45.3

Re: [PATCH v5 7/7] test_bits: add tests for BIT_U*()

Posted by Lucas De Marchi 11 months ago

On Thu, Mar 06, 2025 at 08:29:58PM +0900, Vincent Mailhol via B4 Relay wrote:
>From: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
>
>Add some additional tests in lib/test_bits.c to cover the expected
>results of the fixed type BIT_U*() macros.
>
>Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>

Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>

thanks
Lucas De Marchi

Re: [PATCH v5 7/7] test_bits: add tests for BIT_U*()

Posted by Andy Shevchenko 11 months, 1 week ago

On Thu, Mar 06, 2025 at 08:29:58PM +0900, Vincent Mailhol via B4 Relay wrote:
> From: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
> 
> Add some additional tests in lib/test_bits.c to cover the expected
> results of the fixed type BIT_U*() macros.

Still would be good to have a small assembly test case for GENMASK*() as they
went split and it will be a good regression test in case somebody decides to
unify both without much thinking..

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v5 7/7] test_bits: add tests for BIT_U*()

Posted by Vincent Mailhol 11 months, 1 week ago

On 06/03/2025 at 22:11, Andy Shevchenko wrote:
> On Thu, Mar 06, 2025 at 08:29:58PM +0900, Vincent Mailhol via B4 Relay wrote:
>> From: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
>>
>> Add some additional tests in lib/test_bits.c to cover the expected
>> results of the fixed type BIT_U*() macros.
> 
> Still would be good to have a small assembly test case for GENMASK*() as they
> went split and it will be a good regression test in case somebody decides to
> unify both without much thinking..

Let me confirm that I correctly understood your ask. Would something
like this meet your expectations?

diff --git a/lib/test_bits.c b/lib/test_bits.c
index 72984fae7b81..869b291587e6 100644
--- a/lib/test_bits.c
+++ b/lib/test_bits.c
@@ -136,6 +136,29 @@ static void genmask_input_check_test(struct kunit
*test)
 	KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(127, 0));
 }

+#undef __LINUX_BITS_H
+#undef GENMASK
+#undef GENMASK_ULL
+#define __ASSEMBLY__
+#include <linux/bits.h>
+static void asm_genmask_test(struct kunit *test)
+{
+	KUNIT_EXPECT_EQ(test, 1ul, GENMASK(0, 0));
+	KUNIT_EXPECT_EQ(test, 3ul, GENMASK(1, 0));
+	KUNIT_EXPECT_EQ(test, 6ul, GENMASK(2, 1));
+	KUNIT_EXPECT_EQ(test, 0xFFFFFFFFul, GENMASK(31, 0));
+}
+
+static void asm_genmask_ull_test(struct kunit *test)
+{
+	KUNIT_EXPECT_EQ(test, 1ull, GENMASK_ULL(0, 0));
+	KUNIT_EXPECT_EQ(test, 3ull, GENMASK_ULL(1, 0));
+	KUNIT_EXPECT_EQ(test, 0x000000ffffe00000ull, GENMASK_ULL(39, 21));
+	KUNIT_EXPECT_EQ(test, 0xffffffffffffffffull, GENMASK_ULL(63, 0));
+}
+#undef __ASSEMBLY__
+#undef GENMASK
+#undef GENMASK_ULL

 static struct kunit_case bits_test_cases[] = {
        KUNIT_CASE(__genmask_test),
@@ -144,6 +167,8 @@ static struct kunit_case bits_test_cases[] = {
 	KUNIT_CASE(genmask_ull_test),
 	KUNIT_CASE(genmask_u128_test),
 	KUNIT_CASE(genmask_input_check_test),
+	KUNIT_CASE(asm_genmask_test),
+	KUNIT_CASE(asm_genmask_ull_test),
 	{}
 };


Yours sincerely,
Vincent Mailhol

Re: [PATCH v5 7/7] test_bits: add tests for BIT_U*()

Posted by Andy Shevchenko 11 months, 1 week ago

On Fri, Mar 07, 2025 at 01:08:15AM +0900, Vincent Mailhol wrote:
> On 06/03/2025 at 22:11, Andy Shevchenko wrote:
> > On Thu, Mar 06, 2025 at 08:29:58PM +0900, Vincent Mailhol via B4 Relay wrote:
> >> From: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
> >>
> >> Add some additional tests in lib/test_bits.c to cover the expected
> >> results of the fixed type BIT_U*() macros.
> > 
> > Still would be good to have a small assembly test case for GENMASK*() as they
> > went split and it will be a good regression test in case somebody decides to
> > unify both without much thinking..
> 
> Let me confirm that I correctly understood your ask. Would something
> like this meet your expectations?

I believe it should be written in asm.

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v5 7/7] test_bits: add tests for BIT_U*()

Posted by Vincent Mailhol 11 months, 1 week ago

On 07/03/2025 at 02:55, Andy Shevchenko wrote:
> On Fri, Mar 07, 2025 at 01:08:15AM +0900, Vincent Mailhol wrote:
>> On 06/03/2025 at 22:11, Andy Shevchenko wrote:
>>> On Thu, Mar 06, 2025 at 08:29:58PM +0900, Vincent Mailhol via B4 Relay wrote:
>>>> From: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
>>>>
>>>> Add some additional tests in lib/test_bits.c to cover the expected
>>>> results of the fixed type BIT_U*() macros.
>>>
>>> Still would be good to have a small assembly test case for GENMASK*() as they
>>> went split and it will be a good regression test in case somebody decides to
>>> unify both without much thinking..
>>
>> Let me confirm that I correctly understood your ask. Would something
>> like this meet your expectations?
> 
> I believe it should be written in asm.

I am not confident enough in my assembly skills to submit asm patches to
the kernel. So, I would rather take a pass on that one.

Regardless, if somebody decides to unify both without much thinking as
you said, I am fully confident that the patch will get Nack-ed right
away. So, I do not have any concerns.


Yours sincerely,
Vincent Mailhol

Re: [PATCH v5 7/7] test_bits: add tests for BIT_U*()

Posted by Andy Shevchenko 11 months, 1 week ago

On Fri, Mar 07, 2025 at 07:11:42PM +0900, Vincent Mailhol wrote:
> On 07/03/2025 at 02:55, Andy Shevchenko wrote:
> > On Fri, Mar 07, 2025 at 01:08:15AM +0900, Vincent Mailhol wrote:
> >> On 06/03/2025 at 22:11, Andy Shevchenko wrote:
> >>> On Thu, Mar 06, 2025 at 08:29:58PM +0900, Vincent Mailhol via B4 Relay wrote:
> >>>> From: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
> >>>>
> >>>> Add some additional tests in lib/test_bits.c to cover the expected
> >>>> results of the fixed type BIT_U*() macros.
> >>>
> >>> Still would be good to have a small assembly test case for GENMASK*() as they
> >>> went split and it will be a good regression test in case somebody decides to
> >>> unify both without much thinking..
> >>
> >> Let me confirm that I correctly understood your ask. Would something
> >> like this meet your expectations?
> > 
> > I believe it should be written in asm.
> 
> I am not confident enough in my assembly skills to submit asm patches to
> the kernel. So, I would rather take a pass on that one.
> 
> Regardless, if somebody decides to unify both without much thinking as
> you said, I am fully confident that the patch will get Nack-ed right

As I said above "would be good", if you think it's not feasible by you, perhaps
a comment (FIXME: ?) in the Kunit test cases that we lack of / need an asm test
as well.

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v5 7/7] test_bits: add tests for BIT_U*()

Posted by Vincent Mailhol 11 months, 1 week ago

On 08/03/2025 at 01:07, Andy Shevchenko wrote:
> On Fri, Mar 07, 2025 at 07:11:42PM +0900, Vincent Mailhol wrote:
>> On 07/03/2025 at 02:55, Andy Shevchenko wrote:
>>> On Fri, Mar 07, 2025 at 01:08:15AM +0900, Vincent Mailhol wrote:
>>>> On 06/03/2025 at 22:11, Andy Shevchenko wrote:
>>>>> On Thu, Mar 06, 2025 at 08:29:58PM +0900, Vincent Mailhol via B4 Relay wrote:
>>>>>> From: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
>>>>>>
>>>>>> Add some additional tests in lib/test_bits.c to cover the expected
>>>>>> results of the fixed type BIT_U*() macros.
>>>>>
>>>>> Still would be good to have a small assembly test case for GENMASK*() as they
>>>>> went split and it will be a good regression test in case somebody decides to
>>>>> unify both without much thinking..
>>>>
>>>> Let me confirm that I correctly understood your ask. Would something
>>>> like this meet your expectations?
>>>
>>> I believe it should be written in asm.
>>
>> I am not confident enough in my assembly skills to submit asm patches to
>> the kernel. So, I would rather take a pass on that one.
>>
>> Regardless, if somebody decides to unify both without much thinking as
>> you said, I am fully confident that the patch will get Nack-ed right
> 
> As I said above "would be good", if you think it's not feasible by you, perhaps
> a comment (FIXME: ?) in the Kunit test cases that we lack of / need an asm test
> as well.

Ack. I will add a FIXME message in v6.


Yours sincerely,
Vincent Mailhol