From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jes Sorensen <jes@sgi.com>
Date: Tue, 21 Apr 2009 06:46:49 +0000
Subject: Re: ate_resource->lowest_free_index signed or unsigned?
Message-Id: <49ED6BD9.6060109@sgi.com>
List-Id: <linux-ia64.vger.kernel.org>
References: <49ECA692.2040007@gmail.com>
In-Reply-To: <49ECA692.2040007@gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
To: linux-ia64@vger.kernel.org

Roel Kluin wrote:
> In arch/ia64/include/asm/sn/pcibr_provider.h:94
> 
> struct ate_resource{
>         u64 *ate;
>         u64 num_ate;
>         u64 lowest_free_index;
> };
> 
> as you see lowest_free_index is unsigned,
> 
> but in alloc_ate_resource() and free_ate_resource() it is
> treated as signed:

Hi Roel,

I don't thing it's a big issue to be honest, it just means the tests for
lowest_free_index < 0 are no-ops. I would be fine with a patch that
changes it to signed.

Cheers,
Jes


> static inline void free_ate_resource(struct ate_resource *ate_resource,
>                                      int start)
> {
>         mark_ate(ate_resource, start, ate_resource->ate[start], 0);
>         if ((ate_resource->lowest_free_index > start) ||
>             (ate_resource->lowest_free_index < 0))
>                 ate_resource->lowest_free_index = start;
> }
> 
> /*
>  * alloc_ate_resource:  Allocate the requested number of ATEs.
>  */
> static inline int alloc_ate_resource(struct ate_resource *ate_resource,
>                                      int ate_needed)
> {
>         int start_index;
> 
>         /*
>          * Check for ate exhaustion.
>          */
>         if (ate_resource->lowest_free_index < 0)
>                 return -1;
> 
>         /*
>          * Find the required number of free consecutive ates.
>          */
>         start_index >             find_free_ate(ate_resource, ate_resource->lowest_free_index,
>                           ate_needed);
>         if (start_index >= 0)
>                 mark_ate(ate_resource, start_index, ate_needed, ate_needed);
> 
>         ate_resource->lowest_free_index >             find_free_ate(ate_resource, ate_resource->lowest_free_index, 1);
> 
>         return start_index;
> }
> 
> should it be signed instead?