From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.windriver.com (mail.windriver.com [147.11.1.11]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "mail.windriver.com", Issuer "Intel External Basic Issuing CA 3A" (not verified)) by ozlabs.org (Postfix) with ESMTPS id 036D4B70FF for ; Mon, 24 Jan 2011 17:47:26 +1100 (EST) Message-ID: <4D3D20D4.5040902@windriver.com> Date: Mon, 24 Jan 2011 14:48:52 +0800 From: "tiejun.chen" MIME-Version: 1.0 To: Mitsutaka Amano Subject: Re: About mpc85xx flash memory allocation References: In-Reply-To: Content-Type: text/plain; charset=UTF-8 Cc: linuxppc-dev@lists.ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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 > 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. Tiejun > memory without vmalloc? > > Thanks, > Mitsutaka