From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Gunthorpe Subject: Re: resource sanity fails on ioremap Date: Thu, 4 Feb 2016 22:08:50 -0700 Message-ID: <20160205050850.GA23820@obsidianresearch.com> References: <20160203233701.GA10585@intel.com> <20160204234947.GA20269@obsidianresearch.com> <20160205040500.GA7708@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20160205040500.GA7708-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: tpmdd-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org To: Jarkko Sakkinen Cc: jethro-LmnypSVwBK6EVqv0pETR8A@public.gmane.org, tpmdd-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: tpmdd-devel@lists.sourceforge.net On Thu, Feb 04, 2016 at 08:05:00PM -0800, Jarkko Sakkinen wrote: > 4.4 does not use devm_ioremap_resource(). That is why this is > confusing. If that was the kernel from my master branch, then this > would make sense. It makes sense, the MSFT resource is created by the kernel when it parses the ACPI tables. devm_ioremap_resource creates a child resource of the above owned by the driver. Eg, a PCI example: $ cat /proc/iomem d0000000-d0003fff : 0000:06:00.0 d0000000-d0003fff : r8169 0000:06:00.0 is created by parsing the BAR, it always exists, equivalent to the MSFT resource r8169 is created when the driver attaches to it, and serves to lock the memory range from other drivers. tpm_crb works the same. ioremap complains if a mapping crosses any resource boundary, not just driver created resources. Jason ------------------------------------------------------------------------------ Site24x7 APM Insight: Get Deep Visibility into Application Performance APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month Monitor end-to-end web transactions and take corrective actions now Troubleshoot faster and improve end-user experience. Signup Now! http://pubads.g.doubleclick.net/gampad/clk?id=272487151&iu=/4140