From: Joel Fernandes <joelf@ti.com>
Subject: Re: [PATCH 02/10] crypto: omap-aes: Add useful debug macros
Date: Wed, 14 Aug 2013 18:40:29 -0500
Message-ID: <520C156D.2090003@ti.com>
References: <1376521969-16807-1-git-send-email-joelf@ti.com>  <1376521969-16807-3-git-send-email-joelf@ti.com> <1376522998.1949.118.camel@joe-AO722>
Mime-Version: 1.0
Content-Type: text/plain; charset="ISO-8859-1"
Content-Transfer-Encoding: 7bit
Cc: Herbert Xu <herbert@gondor.hengli.com.au>,
	"David S. Miller" <davem@davemloft.net>,
	Mark Greer <mgreer@animalcreek.com>,
	Tony Lindgren <tony@atomide.com>,
	Santosh Shilimkar <santosh.shilimkar@ti.com>,
	Rajendra Nayak <rnayak@ti.com>,
	Lokesh Vutla <lokeshvutla@ti.com>,
	Linux OMAP List <linux-omap@vger.kernel.org>,
	Linux ARM Kernel List <linux-arm-kernel@lists.infradead.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Linux Crypto Mailing List <linux-crypto@vger.kernel.org>
To: Joe Perches <joe@perches.com>
Return-path: <linux-omap-owner@vger.kernel.org>
In-Reply-To: <1376522998.1949.118.camel@joe-AO722>
Sender: linux-omap-owner@vger.kernel.org
List-Id: linux-crypto.vger.kernel.org

On 08/14/2013 06:29 PM, Joe Perches wrote:
> On Wed, 2013-08-14 at 18:12 -0500, Joel Fernandes wrote:
>> When DEBUG is enabled, these macros can be used to print variables
>> in integer and hex format, and clearly display which registers,
>> offsets and values are being read/written , including printing the
>> names of the offsets and their values.
> []
>> diff --git a/drivers/crypto/omap-aes.c b/drivers/crypto/omap-aes.c
> []
>> @@ -15,6 +15,14 @@
>>  
>>  #define pr_fmt(fmt) "%s: " fmt, __func__
>>  
>> +#ifdef DEBUG
>> +#define prn(num) printk(#num "=%d\n", num)
>> +#define prx(num) printk(#num "=%x\n", num)
> 
> pr_debug?

Sure, can change that.

>> +#else
>> +#define prn(num) do { } while (0)
>> +#define prx(num)  do { } while (0)
>> +#endif
> []
>> @@ -172,13 +180,35 @@ struct omap_aes_dev {
>>  static LIST_HEAD(dev_list);
>>  static DEFINE_SPINLOCK(list_lock);
>>  
>> +#ifdef DEBUG
>> +#define omap_aes_read(dd, offset)					\
>> +	do {								\
>> +		omap_aes_read_1(dd, offset);				\
>> +		pr_debug("omap_aes_read(" #offset ")\n");		\
>> +	} while (0)
>> +
>> +static inline u32 omap_aes_read_1(struct omap_aes_dev *dd, u32 offset)
>> +#else
>>  static inline u32 omap_aes_read(struct omap_aes_dev *dd, u32 offset)
>> +#endif
>>  {
>>  	return __raw_readl(dd->io_base + offset);
>>  }
>>  
>> +#ifdef DEBUG
>> +#define omap_aes_write(dd, offset, value)				\
>> +	do {								\
>> +		pr_debug("omap_aes_write(" #offset "=%x) value=%d\n",	\
>> +			 offset, value);				\
>> +		omap_aes_write_1(dd, offset, value);			\
>> +	} while (0)
>> +
>> +static inline void omap_aes_write_1(struct omap_aes_dev *dd, u32 offset,
>> +				  u32 value)
>> +#else
>>  static inline void omap_aes_write(struct omap_aes_dev *dd, u32 offset,
>>  				  u32 value)
>> +#endif
>>  {
>>  	__raw_writel(value, dd->io_base + offset);
>>  }
> 
> Umm, yuck?
> 
> Is there any real value in read_1 and write_1?

Can you be more descriptive? There is a lot of value in them for debug
to show clearly sequence of read/writes. Moreover, they are no-op'd when
DEBUG is disabled.

Other than the obvious use, I guess it could be rewritten to be bit
cleaner. I can do that.

-Joel