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* [PATCH v3 01/17] resource: Add System RAM resource type
@ 2016-01-05 18:54 Toshi Kani
  2016-01-05 18:54 ` [PATCH v3 02/17] resource: make resource flags handled properly Toshi Kani
                   ` (15 more replies)
  0 siblings, 16 replies; 24+ messages in thread
From: Toshi Kani @ 2016-01-05 18:54 UTC (permalink / raw)
  To: akpm, bp
  Cc: linux-arch, linux-mm, linux-kernel, Linus Torvalds,
	Rafael J. Wysocki, Dan Williams, Toshi Kani

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 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>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
---
 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)
 {

^ permalink raw reply related	[flat|nested] 24+ messages in thread

end of thread, other threads:[~2016-01-24 18:01 UTC | newest]

Thread overview: 24+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-01-05 18:54 [PATCH v3 01/17] resource: Add System RAM resource type Toshi Kani
2016-01-05 18:54 ` [PATCH v3 02/17] resource: make resource flags handled properly Toshi Kani
2016-01-05 18:54 ` [PATCH v3 03/17] resource: Add I/O resource descriptor Toshi Kani
2016-01-05 18:54 ` [PATCH v3 04/17] x86/e820: Set System RAM type and descriptor Toshi Kani
2016-01-05 18:54 ` [PATCH v3 05/17] ia64: " Toshi Kani
2016-01-05 19:04   ` Luck, Tony
2016-01-05 18:54 ` [PATCH v3 06/17] arch: Set IORESOURCE_SYSTEM_RAM to System RAM Toshi Kani
2016-01-24 18:00   ` Borislav Petkov
2016-01-05 18:54 ` [PATCH v3 07/17] kexec: " Toshi Kani
2016-01-07 12:38   ` Dave Young
2016-01-05 18:54 ` [PATCH v3 08/17] xen, mm: " Toshi Kani
2016-01-05 18:54 ` [PATCH v3 09/17] drivers: Initialize resource entry to zero Toshi Kani
2016-01-05 20:57   ` Helge Deller
2016-01-05 18:54 ` [PATCH v3 10/17] resource: Change walk_system_ram to use System RAM type Toshi Kani
2016-01-05 18:54 ` [PATCH v3 11/17] arm/samsung: Change s3c_pm_run_res() " Toshi Kani
2016-01-05 18:54 ` [PATCH v3 12/17] memremap: Change region_intersects() to take @flags and @desc Toshi Kani
2016-01-05 18:54 ` [PATCH v3 13/17] resource: Add walk_iomem_res_desc() Toshi Kani
2016-01-05 18:54 ` [PATCH v3 14/17] x86,nvdimm,kexec: Use walk_iomem_res_desc() for iomem search Toshi Kani
2016-01-07 12:39   ` Dave Young
2016-01-05 18:54 ` [PATCH v3 15/17] x86/kexec: Remove walk_iomem_res() call with GART Toshi Kani
2016-01-07 12:37   ` Dave Young
2016-01-05 18:54 ` [PATCH v3 16/17] resource: Kill walk_iomem_res() Toshi Kani
2016-01-07 12:40   ` Dave Young
2016-01-05 18:54 ` [PATCH v3 17/17] ACPI/EINJ: Allow memory error injection to NVDIMM Toshi Kani

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