Path: csiph.com!feeder.erje.net!2.us.feeder.erje.net!newsfeed.fsmpi.rwth-aachen.de!newsfeed.straub-nv.de!eternal-september.org!feeder.eternal-september.org!aioe.org!bofh.it!news.nic.it!robomod From: Toshi Kani Newsgroups: linux.kernel Subject: [PATCH v2 01/16] resource: Add System RAM resource type Date: Fri, 25 Dec 2015 23:20:01 +0100 Message-ID: X-Original-To: akpm@linux-foundation.org, bp@alien8.de X-Mailer: git-send-email 2.4.3 Sender: robomod@news.nic.it List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Approved: robomod@news.nic.it Lines: 75 Organization: linux.* mail to news gateway X-Original-Cc: linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Linus Torvalds , "Rafael J. Wysocki" , Dan Williams , Toshi Kani X-Original-Date: Fri, 25 Dec 2015 15:09:10 -0700 X-Original-Message-ID: <1451081365-15190-1-git-send-email-toshi.kani@hpe.com> X-Original-Sender: linux-kernel-owner@vger.kernel.org Xref: csiph.com linux.kernel:1298128 I/O resource type, IORESOURCE_MEM, is used for all types of memory-mapped ranges, ex. System RAM, System ROM, Video RAM, Persistent Memory, PCI Bus, PCI MMCONFIG, ACPI Tables, IOAPIC, reserved, and so on. This requires walk_system_ram_range(), walk_system_ram_res(), and region_intersects() to use strcmp() against string "System RAM" to search for System RAM ranges in the iomem table, which is inefficient. __ioremap_caller() and reserve_memtype() on x86, for instance, call walk_system_ram_range() for every request to check if a given range is in System RAM ranges. However, adding a new I/O resource type for System RAM is not a viable option [1]. There are approx. 3800 references to IORESOURCE_MEM in the kernel/drivers, which make it very difficult to distinguish their usages between new type and IORESOURCE_MEM. The I/O resource types are also used by the PNP subsystem. Therefore, this patch introduces an extended I/O resource type, IORESOURCE_SYSTEM_RAM, which consists of IORESOURCE_MEM and a new modifier flag IORESOURCE_SYSRAM [2]. To keep the code 'if (resource_type(r) == IORESOURCE_MEM)' to work continuously for System RAM, resource_ext_type() is added for extracting extended type bit(s). Link[1]: http://lkml.kernel.org/r/<1449168859.9855.54.camel@hpe.com> Link[2]: http://lkml.kernel.org/r/ Cc: Linus Torvalds Cc: Andrew Morton Cc: Borislav Petkov Cc: Rafael J. Wysocki Cc: Dan Williams Signed-off-by: Toshi Kani --- include/linux/ioport.h | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/include/linux/ioport.h b/include/linux/ioport.h index 24bea08..4b65d94 100644 --- a/include/linux/ioport.h +++ b/include/linux/ioport.h @@ -49,12 +49,19 @@ struct resource { #define IORESOURCE_WINDOW 0x00200000 /* forwarded by bridge */ #define IORESOURCE_MUXED 0x00400000 /* Resource is software muxed */ +#define IORESOURCE_EXT_TYPE_BITS 0x01000000 /* Resource extended types */ +#define IORESOURCE_SYSRAM 0x01000000 /* System RAM (modifier) */ + #define IORESOURCE_EXCLUSIVE 0x08000000 /* Userland may not map this resource */ + #define IORESOURCE_DISABLED 0x10000000 #define IORESOURCE_UNSET 0x20000000 /* No address assigned yet */ #define IORESOURCE_AUTO 0x40000000 #define IORESOURCE_BUSY 0x80000000 /* Driver has marked this resource busy */ +/* I/O resource extended types */ +#define IORESOURCE_SYSTEM_RAM (IORESOURCE_MEM|IORESOURCE_SYSRAM) + /* PnP IRQ specific bits (IORESOURCE_BITS) */ #define IORESOURCE_IRQ_HIGHEDGE (1<<0) #define IORESOURCE_IRQ_LOWEDGE (1<<1) @@ -170,6 +177,10 @@ static inline unsigned long resource_type(const struct resource *res) { return res->flags & IORESOURCE_TYPE_BITS; } +static inline unsigned long resource_ext_type(const struct resource *res) +{ + return res->flags & IORESOURCE_EXT_TYPE_BITS; +} /* True iff r1 completely contains r2 */ static inline bool resource_contains(struct resource *r1, struct resource *r2) { -- 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/