From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-bw0-f51.google.com (mail-bw0-f51.google.com [209.85.214.51]) (using TLSv1 with cipher RC4-MD5 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority" (verified OK)) by ozlabs.org (Postfix) with ESMTPS id 2837AB7102 for ; Wed, 26 Jan 2011 21:51:10 +1100 (EST) Received: by bwz10 with SMTP id 10so1256228bwz.38 for ; Wed, 26 Jan 2011 02:51:05 -0800 (PST) MIME-Version: 1.0 In-Reply-To: References: <4D3D20D4.5040902@windriver.com> <4D3E3004.2040308@windriver.com> Date: Wed, 26 Jan 2011 19:51:05 +0900 Message-ID: Subject: Re: About mpc85xx flash memory allocation From: Mitsutaka Amano To: "tiejun.chen" Content-Type: text/plain; charset=ISO-8859-1 Cc: linuxppc-dev@lists.ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Tue, Jan 25, 2011 at 11:17 AM, Mitsutaka Amano wrote: > On Tue, Jan 25, 2011 at 11:05 AM, tiejun.chen = wrote: >> Mitsutaka Amano wrote: >>> On Mon, Jan 24, 2011 at 3:48 PM, tiejun.chen 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 tigh= t. >>>>> >>>>> 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 sam= e space as >>>> vmalloc(). While bootstrap you also can see this associated message li= ke the >>>> follows, >>>> ------ >>>> ...... >>>> =A0* 0xd1000000..0xffbe9000 =A0: vmalloc & ioremap >>> Yeah. My platform says the follow message. >>> >>> =A0 * 0xc9000000..0xdf000000 =A0: 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 add= ress >> directly via /dev/mem from the user space like the following: >> >> fd =3D 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 >> >> >