From: David Laight <David.Laight@ACULAB.COM>
To: "'Chen Gang S'" <gang.chen@sunrus.com.cn>,
        "marcel@holtmann.org" <marcel@holtmann.org>,
        "gustavo@padovan.org" <gustavo@padovan.org>,
        "johan.hedberg@gmail.com" <johan.hedberg@gmail.com>
CC: "David S. Miller" <davem@davemloft.net>,
        "linux-bluetooth@vger.kernel.org" <linux-bluetooth@vger.kernel.org>,
        "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH v2] net: bluetooth: hci_sock: Use 'const void *' instead
 of 'void *' for 2nd parameter of hci_test_bit()
Thread-Topic: [PATCH v2] net: bluetooth: hci_sock: Use 'const void *'
 instead of 'void *' for 2nd parameter of hci_test_bit()
Thread-Index: AQHQPywzeR6i5TQh3kGdfi5IMQnXPJzgZU2A
Date: Wed, 4 Feb 2015 11:59:39 +0000
Message-ID: <063D6719AE5E284EB5DD2968C1650D6D1CADA5E1@AcuExch.aculab.com>
References: <54CFE8BE.5030700@sunrus.com.cn>
In-Reply-To: <54CFE8BE.5030700@sunrus.com.cn>
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From: Chen Gang S
> -static inline int hci_test_bit(int nr, void *addr)
> +static inline int hci_test_bit(int nr, const void *addr)
>  {
>  	return *((__u32 *) addr + (nr >> 5)) & ((__u32) 1 << (nr & 31));
>  }

Is there a 'standard' function lurking that will do the above.
On x86 the cpus 'bit test' instruction will handle bit numbers
greater than the word size - so it can be a single instruction.

	David

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