On Tue, Jan 25, 2011 at 11:17 AM, Mitsutaka Amano <mitsutaka.am...@gmail.com> wrote: > 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) I confused and misunderstand that. it has to use as a rootfs. so It can't use a userland program. Of cource, it can be force mapping to the userspace. but system will be unstable. I think.
Mitsutaka > > 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
