Please help with the OMAP static mapping mess

[Nicolas Pitre]

On Mon, 3 Oct 2011, Nicolas Pitre wrote:

> On Mon, 3 Oct 2011, Tony Lindgren wrote:
> 
> > * Nicolas Pitre <nico at fluxnic.net> [111003 11:26]:
> > > 
> > > Furthermore... there is also a static mapping for physical address 
> > > 0x4e000000 using virtual address 0xff100000 which is already reserved 
> > > for other purposes i.e. the consistent DMA area.  It is not immediately 
> > > obvious where this comes from without being intimate with the OMAP code. 
> > > Can this be fixed as well i.e. moved elsewhere please?
> > 
> > This sounds like a bug somewhere. Which omap are you seeing this on?
> 
> OMAP4430 on a Panda board.
> 
> Here are the static mappings I'm seeing:
> 
> phys = 0x44000000 virt = 0xf8000000 size = 0x100000
> phys = 0x4a000000 virt = 0xfc000000 size = 0x400000
> phys = 0x50000000 virt = 0xf9000000 size = 0x100000
> phys = 0x4c000000 virt = 0xfd100000 size = 0x100000
> phys = 0x4d000000 virt = 0xfe100000 size = 0x100000
> phys = 0x4e000000 virt = 0xff100000 size = 0x100000 <---
> phys = 0x48000000 virt = 0xfa000000 size = 0x400000
> phys = 0x54000000 virt = 0xfe800000 size = 0x800000

It looks like this comes from OMAP44XX_DMM_VIRT.

#define OMAP44XX_DMM_PHYS       OMAP44XX_DMM_BASE
                                                /* 0x4e000000 --> 0xfd300000 */
#define OMAP44XX_DMM_VIRT       (OMAP44XX_DMM_PHYS + OMAP4_L3_PER_IO_OFFSET)
#define OMAP44XX_DMM_SIZE       SZ_1M

The comment suggesting a mapping correspondance is obviously wrong. We have:

#define OMAP44XX_DMM_BASE       0x4e000000
#define OMAP4_L3_PER_IO_OFFSET  0xb1100000

Hence 0x4e000000 + 0xb1100000 = 0xff100000.


Nicolas








> 
> It is also possible that I might have screwed something up on my side.  
> What is located at 0x4e000000?
> 
> 
> Nicolas
>