If you don't have CONFIG_DISCONTIGMEM support enabled, this used to just map to a simple macro. 0xc1c8c000-0xc0000000+0x10000000 = 11c8c000 There should be another layer of indirection if CONFIG_DISCONTIGMEM support is turned on which needs to be defined properly. Do you have that enabled by chance? Regards, Richard W. /* * Page offset: 3GB */ #define PAGE_OFFSET (0xc0000000UL) #define PHYS_OFFSET (0x80000000UL) /* * On 2420 ES2, the dram is contiguous */ #define __virt_to_phys__is_a_macro #define __virt_to_phys(vpage) ((vpage) - PAGE_OFFSET + PHYS_OFFSET ) #define __phys_to_virt__is_a_macro #define __phys_to_virt(ppage) (((ppage) - PHYS_OFFSET ) + PAGE_OFFSET) > -----Original Message----- > From: linux-omap-open-source-bounces@xxxxxxxxxxxxxx [mailto:linux-omap- > open-source-bounces@xxxxxxxxxxxxxx] On Behalf Of Tim Bird > Sent: Thursday, June 09, 2005 12:04 PM > To: linux-omap-open-source@xxxxxxxxxxxxxx; kernelnewbies@xxxxxxxxxxxx > Subject: virt_to_phys - what am I doing wrong? > > Hi all, > > I'm trying to use virt_to_phys() to find the physical address > of some kernel RAM. (This is an on ARM OSK board). > It's not working as I expected: > > membase = kmalloc(DEBUG_MEM_LENGTH, GFP_ATOMIC); > physbase = virt_to_phys(membase); > printk("membase=0x%p\n", membase); > printk("physbase=0x%lu\n", physbase); > > Gives me: > membase=0xc1c8c000 > physbase=0x298369024 > > physbase isn't in the range of real physical memory on my > machine. (I'm only interested in the first page of the > allocation, so I don't care if subsequent pages are > not physically contiguous.) > > Other uses of virt_to_phys() that I see in the the kernel source > seem to only use IOmapped mem, or DMA-able mem. > > Is this even the right approach? Do I need to walk page > tables myself? I thought there would be a simple routine > for this, but I haven't found it. > > Any help would be much appreciated. > > Thanks, > -- Tim > > ============================= > Tim Bird > Architecture Group Chair, CE Linux Forum > Senior Staff Engineer, Sony Electronics > ============================= > _______________________________________________ > Linux-omap-open-source mailing list > Linux-omap-open-source@xxxxxxxxxxxxxx > http://linux.omap.com/mailman/listinfo/linux-omap-open-source -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
