Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756135AbbLAQy2 (ORCPT ); Tue, 1 Dec 2015 11:54:28 -0500 Received: from mail-yk0-f176.google.com ([209.85.160.176]:33828 "EHLO mail-yk0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754881AbbLAQyY (ORCPT ); Tue, 1 Dec 2015 11:54:24 -0500 MIME-Version: 1.0 In-Reply-To: <20151201135000.GB4341@pd.tnic> References: <1448404418-28800-1-git-send-email-toshi.kani@hpe.com> <1448404418-28800-2-git-send-email-toshi.kani@hpe.com> <20151201135000.GB4341@pd.tnic> Date: Tue, 1 Dec 2015 08:54:23 -0800 Message-ID: Subject: Re: [PATCH v3 1/3] resource: Add @flags to region_intersects() From: Dan Williams To: Borislav Petkov Cc: Toshi Kani , Andrew Morton , "Rafael J. Wysocki" , Tony Luck , Vishal L Verma , Linux MM , "linux-nvdimm@lists.01.org" , Linux ACPI , "linux-kernel@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2979 Lines: 70 On Tue, Dec 1, 2015 at 5:50 AM, Borislav Petkov wrote: > On Tue, Nov 24, 2015 at 03:33:36PM -0700, Toshi Kani wrote: >> region_intersects() checks if a specified region partially overlaps >> or fully eclipses a resource identified by @name. It currently sets >> resource flags statically, which prevents the caller from specifying >> a non-RAM region, such as persistent memory. Add @flags so that >> any region can be specified to the function. >> >> A helper function, region_intersects_ram(), is added so that the >> callers that check a RAM region do not have to specify its iomem >> resource name and flags. This interface is exported for modules, >> such as the EINJ driver. >> >> Signed-off-by: Toshi Kani >> Reviewed-by: Dan Williams >> Cc: Andrew Morton >> Cc: Vishal Verma >> --- >> include/linux/mm.h | 4 +++- >> kernel/memremap.c | 5 ++--- >> kernel/resource.c | 23 ++++++++++++++++------- >> 3 files changed, 21 insertions(+), 11 deletions(-) >> >> diff --git a/include/linux/mm.h b/include/linux/mm.h >> index 00bad77..c776af3 100644 >> --- a/include/linux/mm.h >> +++ b/include/linux/mm.h >> @@ -362,7 +362,9 @@ enum { >> REGION_MIXED, >> }; >> >> -int region_intersects(resource_size_t offset, size_t size, const char *type); >> +int region_intersects(resource_size_t offset, size_t size, const char *type, >> + unsigned long flags); >> +int region_intersects_ram(resource_size_t offset, size_t size); >> >> /* Support for virtually mapped pages */ >> struct page *vmalloc_to_page(const void *addr); >> diff --git a/kernel/memremap.c b/kernel/memremap.c >> index 7658d32..98f52f1 100644 >> --- a/kernel/memremap.c >> +++ b/kernel/memremap.c >> @@ -57,7 +57,7 @@ static void *try_ram_remap(resource_size_t offset, size_t size) >> */ >> void *memremap(resource_size_t offset, size_t size, unsigned long flags) >> { >> - int is_ram = region_intersects(offset, size, "System RAM"); > > Ok, question: why do those resource things types gets identified with > a string?! We have here "System RAM" and next patch adds "Persistent > Memory". > > And "persistent memory" or "System RaM" won't work and this is just > silly. > > Couldn't struct resource have gained some typedef flags instead which we > can much easily test? Using the strings looks really yucky. > At least in the case of region_intersects() I was just following existing strcmp() convention from walk_system_ram_range. We could define 'const char *system_ram = "System RAM"' somewhere and then do pointer comparisons to cut down on the thrash of adding new flags to 'struct resource'? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/