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authorToshi Kani <toshi.kani@hpe.com>2016-01-26 21:57:17 +0100
committerIngo Molnar <mingo@kernel.org>2016-01-30 09:49:56 +0100
commit9babd5c8caa6e62c116efc3a64a09f65af4112b0 (patch)
tree01e864aead6fe45fb5f9cef9b05ceae7075eb326 /include/linux/ioport.h
parentad0b40fa944628d6f30b40266a599b285d70a266 (diff)
resource: Add System RAM resource type
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. Link[1]: http://lkml.kernel.org/r/1449168859.9855.54.camel@hpe.com Link[2]: http://lkml.kernel.org/r/CA+55aFy4WQrWexC4u2LxX9Mw2NVoznw7p3Yh=iF4Xtf7zKWnRw@mail.gmail.com Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Hanjun Guo <hanjun.guo@linaro.org> Cc: Jakub Sitnicki <jsitnicki@gmail.com> Cc: Jiang Liu <jiang.liu@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Cc: linux-arch@vger.kernel.org Cc: linux-mm <linux-mm@kvack.org> Link: http://lkml.kernel.org/r/1453841853-11383-2-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include/linux/ioport.h')
-rw-r--r--include/linux/ioport.h11
1 files changed, 11 insertions, 0 deletions
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)
{