From: Andreas Schwab <schwab@linux-m68k.org>
To: Brad Boyer <flar@allandria.com>
Cc: Matthew Wilcox <willy@infradead.org>, linux-m68k@lists.linux-m68k.org
Subject: Re: clear_bit_unlock_is_negative_byte
Date: Fri, 21 Jul 2023 11:18:35 +0200 [thread overview]
Message-ID: <87bkg5bp1w.fsf@igel.home> (raw)
In-Reply-To: <20230721085711.GA6785@allandria.com> (Brad Boyer's message of "Fri, 21 Jul 2023 01:57:11 -0700")
On Jul 21 2023, Brad Boyer wrote:
> On Fri, Jul 21, 2023 at 08:34:55AM +0200, Andreas Schwab wrote:
>> On Jul 20 2023, Matthew Wilcox wrote:
>>
>> > +static inline bool clear_bit_unlock_is_negative_byte(unsigned int nr,
>> > + volatile unsigned long *p)
>> > +{
>> > + char result;
>> > + char mask = 1 << nr; /* nr guaranteed to be < 7 */
>> > +
>> > + __asm__ __volatile__ ("eori %1, %2; smi %0"
>>
>> Why are you using XOR if you want to clear a bit? If it operates on a
>> byte, why does it receive a pointer to long?
>
> I presume the thing with byte is to try to save an extension word.
Why is this hardcoded in the function name?
--
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510 2552 DF73 E780 A9DA AEC1
"And now for something completely different."
next prev parent reply other threads:[~2023-07-21 9:18 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-20 19:27 clear_bit_unlock_is_negative_byte Matthew Wilcox
2023-07-20 22:37 ` clear_bit_unlock_is_negative_byte Michael Schmitz
2023-07-21 1:12 ` clear_bit_unlock_is_negative_byte Michael Schmitz
2023-07-21 1:32 ` clear_bit_unlock_is_negative_byte Matthew Wilcox
2023-07-21 1:43 ` clear_bit_unlock_is_negative_byte Michael Schmitz
2023-07-21 17:03 ` clear_bit_unlock_is_negative_byte Matthew Wilcox
2023-07-21 22:07 ` clear_bit_unlock_is_negative_byte Michael Schmitz
2023-07-22 6:24 ` clear_bit_unlock_is_negative_byte Andreas Schwab
2023-07-22 14:45 ` clear_bit_unlock_is_negative_byte Matthew Wilcox
2023-07-22 15:26 ` clear_bit_unlock_is_negative_byte Andreas Schwab
2023-07-22 15:38 ` clear_bit_unlock_is_negative_byte Matthew Wilcox
2023-07-21 6:34 ` clear_bit_unlock_is_negative_byte Andreas Schwab
2023-07-21 8:57 ` clear_bit_unlock_is_negative_byte Brad Boyer
2023-07-21 9:18 ` Andreas Schwab [this message]
2023-07-21 11:59 ` clear_bit_unlock_is_negative_byte Matthew Wilcox
2023-07-21 12:52 ` clear_bit_unlock_is_negative_byte Andreas Schwab
2023-07-21 20:29 ` clear_bit_unlock_is_negative_byte Brad Boyer
2023-07-22 3:42 ` clear_bit_unlock_is_negative_byte Matthew Wilcox
2023-07-22 23:49 ` clear_bit_unlock_is_negative_byte Brad Boyer
2023-07-23 1:08 ` clear_bit_unlock_is_negative_byte Michael Schmitz
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