[Fwd: Re: Allocating a cache-safe buffer for DMA devices and drivers]

[Fwd: Re: Allocating a cache-safe buffer for DMA devices and drivers]

[Xavier Grave]

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Sorry, forgot to cc...

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From: Xavier Grave <grave@ipno.in2p3.fr>
To: "Garcia Jérémie" <GARCIAJ@3il.fr>
Subject: Re: Allocating a cache-safe buffer for DMA devices and drivers
Date: Mon, 29 Aug 2005 11:31:48 +0200
Message-ID: <1125307903.5440.13.camel@ipnnarval>

Hi,

Something like that maybe :

 virtual_ad = (unsigned long *) kmalloc(sizeof(long)*taille_dma,
                                         GFP_KERNEL|GFP_DMA|GFP_ATOMIC);

O+ xavier

Le lundi 29 août 2005 à 11:16 +0200, Garcia Jérémie a écrit :
> Hi everybody, I have to port a vxWorks appz to Linux Montavista running on a powerPC 405EP based architecture.
> In this one, we use the following vxWorks system call: cacheDmaMalloc( ) whose man page is :
> 
> NAME
>     cacheDmaMalloc( ) - allocate a cache-safe buffer for DMA devices and drivers
> 
> SYNOPSIS
> void * cacheDmaMalloc
>     (
>     size_t bytes              /* number of bytes to allocate */
>     )
> 
> DESCRIPTION
>     This routine returns a pointer to a section of memory that will not experience any cache coherency problems. Function pointers in the CACHE_FUNCS structure provide access to DMA support routines.
> 
> RETURNS
>     A pointer to the cache-safe buffer, or NULL. 
> 
> 
> I need to handle the given amount of memory from the user space. 
> So could anyone told how to achieve the same goal on Linux with these constraints?
> 
> Tks a lot for your precious help!
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