Re: [HOWTO] accessing the DMA mapped data

2007-05-11 Thread Muli Ben-Yehuda
On Thu, May 10, 2007 at 04:47:32AM -0700, David Miller wrote: > From: Mahesh <[EMAIL PROTECTED]> > Date: Thu, 10 May 2007 17:11:17 +0530 > > > Hi, > You haven't given an example of where this might actually > > happen. > > The driver is where the DMA mappings almost always > > occur because > tha

Re: [HOWTO] accessing the DMA mapped data

2007-05-10 Thread Roland Dreier
> Here I am dealing with a infiniband (see www.openfabrics.org) > network device driver. The layer above the driver is the standard > infiniband core interface. Now I have a situation where I need to > peek into the packets and do some modifications(some hacking). So I > just want know whether

Re: [HOWTO] accessing the DMA mapped data

2007-05-10 Thread David Miller
From: Mahesh <[EMAIL PROTECTED]> Date: Thu, 10 May 2007 17:11:17 +0530 > Hi, > You haven't given an example of where this might actually > happen. > > The driver is where the DMA mappings almost always > occur because > that is the layer that knows the bus technology and > therefore > the correct

Re: [HOWTO] accessing the DMA mapped data

2007-05-10 Thread Mahesh
Hi, You haven't given an example of where this might actually happen. The driver is where the DMA mappings almost always occur because that is the layer that knows the bus technology and therefore the correct DMA interfaces to call. What kind of driver do you have and what is this upper layer d

Re: [HOWTO] accessing the DMA mapped data

2007-05-10 Thread David Miller
From: Mahesh <[EMAIL PROTECTED]> Date: Thu, 10 May 2007 16:49:03 +0530 > I think you have not understood my question properly. My problem is, the > layer above the driver will do > dma_map_single on a kmalloc'ed buffer and passes the result (bus > address) to the device driver. Now > the driver

Re: [HOWTO] accessing the DMA mapped data

2007-05-10 Thread Mahesh
Hi Miller, Thanks for replying. You can eithe keep track of this yourself, or (depending upon your usage) you might be able to use DMA pools, see dma_pool_create() and friends. I think you have not understood my question properly. My problem is, the layer above the driver will do dma_map_sin

Re: [HOWTO] accessing the DMA mapped data

2007-05-10 Thread David Miller
From: Mahesh <[EMAIL PROTECTED]> Date: Thu, 10 May 2007 13:28:13 +0530 > I have a small question regarding the accessing the data in the DMA > mapped region (in the driver). In my driver I only have the > 'dma_addr_t addr' variable which is result after the 'dma_map_single'. > I don't have ac

[HOWTO] accessing the DMA mapped data

2007-05-10 Thread Mahesh
Hi list, I have a small question regarding the accessing the data in the DMA mapped region (in the driver). In my driver I only have the 'dma_addr_t addr' variable which is result after the 'dma_map_single'. I don't have access to the virtual address of the data region. Is there helper rou