Subject: Re: [PATCH 1/4] ucc_geth: Change private immrbar_virt_to_phys to generic iopa

From: Timur Tabi <[email-masked]>
Date: Wed, 07 Feb 2007 11:03:02 -0600

Kumar Gala wrote:

> If its been mapped with ioremap() you know the physical address already 
> so why do you need iopa().  

That's what the original function immrbar_virt_to_phys() does.  We're trying to 
get rid of it, because we thought is redundant with iopa().

static inline unsigned long immrbar_virt_to_phys(volatile void * address)
{
	if ( ((u32)address >= (u32)qe_immr) &&
			((u32)address < ((u32)qe_immr + QE_IMMAP_SIZE)) )
		return (unsigned long)(address - (u32)qe_immr +
				(u32)get_qe_base());
	return (unsigned long)virt_to_phys(address);
}

get_qe_base() does a search of the OF tree the first time it's called.

Here's the code that calls immrbar_virt_to_phys():

	out_be32(&ugeth->p_send_q_mem_reg->sqqd[i].bd_ring_base,
		 (u32) immrbar_virt_to_phys(ugeth->
					    p_tx_bd_ring[i]));

Would it be better to replace this code with something like this:

out_be32(&ugeth->p_send_q_mem_reg->sqqd[i].bd_ring_base,
	get_qe_base() + ((void *) ugeth->p_tx_bd_ring[i] - (void *) qe_immr));

-- 
Timur Tabi
Linux Kernel Developer @ Freescale