On Tue, Jan 25, 2011 at 11:05 AM, tiejun.chen <tiejun.c...@windriver.com> wrote: > Mitsutaka Amano wrote: >> On Mon, Jan 24, 2011 at 3:48 PM, tiejun.chen <tiejun.c...@windriver.com> >> wrote: >>> Mitsutaka Amano wrote: >>>> Hi all, >>>> >>>> I'm testing the ppc platform is based on mpc85xx. 256MB Flash memory >>>> has been installed. Then I found this entries. >>>> >>>> /proc/vmallocinfo >>>> ~~~ >>>> 0xc9100000-0xd9101000 268439552 of_flash_probe+0x290/0x814 ioremap >>>> >>>> physmap_of allocated 268MB over to the vmalloc. vmalloc space is tight. >>>> >>>> Why does we need mpc platforms to flash memory allocation? I know >>> This should not be dedicated to so-called mpc platform. And we always use >>> ioremap() to map the device space. And on PPC ioremap also use the same >>> space as >>> vmalloc(). While bootstrap you also can see this associated message like the >>> follows, >>> ------ >>> ...... >>> * 0xd1000000..0xffbe9000 : vmalloc & ioremap >> Yeah. My platform says the follow message. >> >> * 0xc9000000..0xdf000000 : vmalloc & ioremap > > Any reason why you don't access > 0xdf000000?
Higher than 0xdf000000 has to map TLB for using other peripherals. it's 400MB over. > >> >> The default vmalloc & ioremap space was about 200MB. so I increased >> that by decreasing lowmem. >> But If possible, I hope to keep default maps. So I don't want to use >> vmalloc & ioremap >> >>>> other architectures don't allocate to the vmalloc. >>>> The design of the hardware? or Is there the way to use the flash >>> You can open /dev/mem then mmap() with a appropriate offset to access the >>> device >>> space including flash. >> I use the device tree(dts) and define flash partitions. Also I use CFI >> driver and CFI_PHYSMAP_OF for device tree. >> Is there the reference driver in what uses mmap() kernel tree? I think >> I have to write a driver what can support dts and mmap() with a >> appropriate offset to access the device. > > You should not write anything again. And you can access any physical address > directly via /dev/mem from the user space like the following: > > fd = open(/dev/mem,); > mmap(fd + offset); Thanks for letting me know. I want to use in combination with device tree. So I'll write a driver based on physmap_of.c(such as mmap_of.c) Thanks, Mitsutaka > > Tiejun > >> >> Thanks, >> Mitsutaka >> >>> Tiejun >>> >>>> memory without vmalloc? >>>> >>>> Thanks, >>>> Mitsutaka > > _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
