From: Toshi Kani <[email protected]> The IORESOURCE_MEM I/O resource type 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, see [1]. There are approx. 3800 references to IORESOURCE_MEM in the kernel/drivers, which makes 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, introduce an extended I/O resource type, IORESOURCE_SYSTEM_RAM, which consists of IORESOURCE_MEM and a new modifier flag IORESOURCE_SYSRAM, see [2]. To keep the code 'if (resource_type(r) == IORESOURCE_MEM)' still working for System RAM, resource_ext_type() is added for extracting extended type bits. Signed-off-by: Toshi Kani <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Dan Williams <[email protected]> Cc: Hanjun Guo <[email protected]> Cc: Jakub Sitnicki <[email protected]> Cc: Jiang Liu <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: [email protected] Cc: linux-mm <[email protected]> Cc: "Rafael J. Wysocki" <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Link[1]: http://lkml.kernel.org/r/[email protected] Link[2]: http://lkml.kernel.org/r/CA+55aFy4WQrWexC4u2LxX9Mw2NVoznw7p3Yh=if4xtf7zkw...@mail.gmail.com Signed-off-by: Borislav Petkov <[email protected]> --- include/linux/ioport.h | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/include/linux/ioport.h b/include/linux/ioport.h index 24bea087e7af..4b65d944717f 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) { -- 2.3.5
