19 files changed, 466 insertions, 141 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-pci-devices-cciss b/Documentation/ABI/testing/sysfs-bus-pci-devices-cciss
index 0a92a7c93a62..4f29e5f1ebfa 100644
--- a/Documentation/ABI/testing/sysfs-bus-pci-devices-cciss
+++ b/Documentation/ABI/testing/sysfs-bus-pci-devices-cciss
@@ -31,3 +31,31 @@ Date:		March 2009
 Kernel Version: 2.6.30
 Contact:        iss_storagedev@hp.com
 Description:    A symbolic link to /sys/block/cciss!cXdY
+Where:          /sys/bus/pci/devices/<dev>/ccissX/rescan
+Date:           August 2009
+Kernel Version: 2.6.31
+Contact:        iss_storagedev@hp.com
+Description:    Kicks of a rescan of the controller to discover logical
+                drive topology changes.
+Where:          /sys/bus/pci/devices/<dev>/ccissX/cXdY/lunid
+Date:           August 2009
+Kernel Version: 2.6.31
+Contact:        iss_storagedev@hp.com
+Description:    Displays the 8-byte LUN ID used to address logical
+                drive Y of controller X.
+Where:          /sys/bus/pci/devices/<dev>/ccissX/cXdY/raid_level
+Date:           August 2009
+Kernel Version: 2.6.31
+Contact:        iss_storagedev@hp.com
+Description:    Displays the RAID level of logical drive Y of
+                controller X.
+Where:          /sys/bus/pci/devices/<dev>/ccissX/cXdY/usage_count
+Date:           August 2009
+Kernel Version: 2.6.31
+Contact:        iss_storagedev@hp.com
+Description:    Displays the usage count (number of opens) of logical drive Y
+                of controller X.
diff --git a/Documentation/SubmittingPatches b/Documentation/SubmittingPatches
index b7f9d3b4bbf6..72651f788f4e 100644
--- a/Documentation/SubmittingPatches
+++ b/Documentation/SubmittingPatches
@@ -232,7 +232,7 @@ your e-mail client so that it sends your patches untouched.
 When sending patches to Linus, always follow step #7.
 Large changes are not appropriate for mailing lists, and some
-maintainers.  If your patch, uncompressed, exceeds 40 kB in size,
+maintainers.  If your patch, uncompressed, exceeds 300 kB in size,
 it is preferred that you store your patch on an Internet-accessible
 server, and provide instead a URL (link) pointing to your patch.
diff --git a/Documentation/arm/tcm.txt b/Documentation/arm/tcm.txt
new file mode 100644
index 000000000000..77fd9376e6d7
--- /dev/null
+++ b/Documentation/arm/tcm.txt
@@ -0,0 +1,147 @@
+ARM TCM (Tightly-Coupled Memory) handling in Linux
+----
+Written by Linus Walleij <linus.walleij@stericsson.com>
+Some ARM SoC:s have a so-called TCM (Tightly-Coupled Memory).
+This is usually just a few (4-64) KiB of RAM inside the ARM
+processor.
+Due to being embedded inside the CPU The TCM has a
+Harvard-architecture, so there is an ITCM (instruction TCM)
+and a DTCM (data TCM). The DTCM can not contain any
+instructions, but the ITCM can actually contain data.
+The size of DTCM or ITCM is minimum 4KiB so the typical
+minimum configuration is 4KiB ITCM and 4KiB DTCM.
+ARM CPU:s have special registers to read out status, physical
+location and size of TCM memories. arch/arm/include/asm/cputype.h
+defines a CPUID_TCM register that you can read out from the
+system control coprocessor. Documentation from ARM can be found
+at http://infocenter.arm.com, search for "TCM Status Register"
+to see documents for all CPUs. Reading this register you can
+determine if ITCM (bit 0) and/or DTCM (bit 16) is present in the
+machine.
+There is further a TCM region register (search for "TCM Region
+Registers" at the ARM site) that can report and modify the location
+size of TCM memories at runtime. This is used to read out and modify
+TCM location and size. Notice that this is not a MMU table: you
+actually move the physical location of the TCM around. At the
+place you put it, it will mask any underlying RAM from the
+CPU so it is usually wise not to overlap any physical RAM with
+the TCM.
+The TCM memory can then be remapped to another address again using
+the MMU, but notice that the TCM if often used in situations where
+the MMU is turned off. To avoid confusion the current Linux
+implementation will map the TCM 1 to 1 from physical to virtual
+memory in the location specified by the machine.
+TCM is used for a few things:
+- FIQ and other interrupt handlers that need deterministic
+  timing and cannot wait for cache misses.
+- Idle loops where all external RAM is set to self-refresh
+  retention mode, so only on-chip RAM is accessible by
+  the CPU and then we hang inside ITCM waiting for an
+  interrupt.
+- Other operations which implies shutting off or reconfiguring
+  the external RAM controller.
+There is an interface for using TCM on the ARM architecture
+in <asm/tcm.h>. Using this interface it is possible to:
+- Define the physical address and size of ITCM and DTCM.
+- Tag functions to be compiled into ITCM.
+- Tag data and constants to be allocated to DTCM and ITCM.
+- Have the remaining TCM RAM added to a special
+  allocation pool with gen_pool_create() and gen_pool_add()
+  and provice tcm_alloc() and tcm_free() for this
+  memory. Such a heap is great for things like saving
+  device state when shutting off device power domains.
+A machine that has TCM memory shall select HAVE_TCM in
+arch/arm/Kconfig for itself, and then the
+rest of the functionality will depend on the physical
+location and size of ITCM and DTCM to be defined in
+mach/memory.h for the machine. Code that needs to use
+TCM shall #include <asm/tcm.h> If the TCM is not located
+at the place given in memory.h it will be moved using
+the TCM Region registers.
+Functions to go into itcm can be tagged like this:
+int __tcmfunc foo(int bar);
+Variables to go into dtcm can be tagged like this:
+int __tcmdata foo;
+Constants can be tagged like this:
+int __tcmconst foo;
+To put assembler into TCM just use
+.section ".tcm.text" or .section ".tcm.data"
+respectively.
+Example code:
+#include <asm/tcm.h>
+/* Uninitialized data */
+static u32 __tcmdata tcmvar;
+/* Initialized data */
+static u32 __tcmdata tcmassigned = 0x2BADBABEU;
+/* Constant */
+static const u32 __tcmconst tcmconst = 0xCAFEBABEU;
+static void __tcmlocalfunc tcm_to_tcm(void)
+{
+        int i;
+        for (i = 0; i < 100; i++)
+                tcmvar ++;
+}
+static void __tcmfunc hello_tcm(void)
+{
+        /* Some abstract code that runs in ITCM */
+        int i;
+        for (i = 0; i < 100; i++) {
+                tcmvar ++;
+        }
+        tcm_to_tcm();
+}
+static void __init test_tcm(void)
+{
+        u32 *tcmem;
+        int i;
+        hello_tcm();
+        printk("Hello TCM executed from ITCM RAM\n");
+        printk("TCM variable from testrun: %u @ %p\n", tcmvar, &tcmvar);
+        tcmvar = 0xDEADBEEFU;
+        printk("TCM variable: 0x%x @ %p\n", tcmvar, &tcmvar);
+        printk("TCM assigned variable: 0x%x @ %p\n", tcmassigned, &tcmassigned);
+        printk("TCM constant: 0x%x @ %p\n", tcmconst, &tcmconst);
+        /* Allocate some TCM memory from the pool */
+        tcmem = tcm_alloc(20);
+        if (tcmem) {
+                printk("TCM Allocated 20 bytes of TCM @ %p\n", tcmem);
+                tcmem[0] = 0xDEADBEEFU;
+                tcmem[1] = 0x2BADBABEU;
+                tcmem[2] = 0xCAFEBABEU;
+                tcmem[3] = 0xDEADBEEFU;
+                tcmem[4] = 0x2BADBABEU;
+                for (i = 0; i < 5; i++)
+                        printk("TCM tcmem[%d] = %08x\n", i, tcmem[i]);
+                tcm_free(tcmem, 20);
+        }
+}
diff --git a/Documentation/cgroups/cgroups.txt b/Documentation/cgroups/cgroups.txt
index 455d4e6d346d..0b33bfe7dde9 100644
--- a/Documentation/cgroups/cgroups.txt
+++ b/Documentation/cgroups/cgroups.txt
@@ -227,7 +227,14 @@ as the path relative to the root of the cgroup file system.
 Each cgroup is represented by a directory in the cgroup file system
 containing the following files describing that cgroup:
- - tasks: list of tasks (by pid) attached to that cgroup
+ - tasks: list of tasks (by pid) attached to that cgroup.  This list
+   is not guaranteed to be sorted.  Writing a thread id into this file
+   moves the thread into this cgroup.
+ - cgroup.procs: list of tgids in the cgroup.  This list is not
+   guaranteed to be sorted or free of duplicate tgids, and userspace
+   should sort/uniquify the list if this property is required.
+   Writing a tgid into this file moves all threads with that tgid into
+   this cgroup.
 - notify_on_release flag: run the release agent on exit?
 - release_agent: the path to use for release notifications (this file
   exists in the top cgroup only)
@@ -374,7 +381,7 @@ Now you want to do something with this cgroup.
 In this directory you can find several files:
 # ls
-notify_on_release tasks
+cgroup.procs notify_on_release tasks
 (plus whatever files added by the attached subsystems)
 Now attach your shell to this cgroup:
diff --git a/Documentation/filesystems/ext4.txt b/Documentation/filesystems/ext4.txt
index 18b5ec8cea45..bf4f4b7e11b3 100644
--- a/Documentation/filesystems/ext4.txt
+++ b/Documentation/filesystems/ext4.txt
@@ -282,9 +282,16 @@ stripe=n		Number of filesystem blocks that mballoc will try
                        to use for allocation size and alignment. For RAID5/6
                        systems this should be the number of data
                        disks *  RAID chunk size in file system blocks.
-delalloc        (*)     Deferring block allocation until write-out time.
-nodelalloc              Disable delayed allocation. Blocks are allocation
+delalloc        (*)     Defer block allocation until just before ext4
-                        when data is copied from user to page cache.
+                        writes out the block(s) in question.  This
+                        allows ext4 to better allocation decisions
+                        more efficiently.
+nodelalloc              Disable delayed allocation.  Blocks are allocated
+                        when the data is copied from userspace to the
+                        page cache, either via the write(2) system call
+                        or when an mmap'ed page which was previously
+                        unallocated is written for the first time.
 max_batch_time=usec     Maximum amount of time ext4 should wait for
                        additional filesystem operations to be batch
diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt
index b5aee7838a00..2c48f945546b 100644
--- a/Documentation/filesystems/proc.txt
+++ b/Documentation/filesystems/proc.txt
@@ -1113,7 +1113,6 @@ Table 1-12: Files in /proc/fs/ext4/<devname>
 ..............................................................................
 File            Content                                        
 mb_groups       details of multiblock allocator buddy cache of free blocks
- mb_history      multiblock allocation history
 ..............................................................................
diff --git a/Documentation/filesystems/vfat.txt b/Documentation/filesystems/vfat.txt
index b58b84b50fa2..eed520fd0c8e 100644
--- a/Documentation/filesystems/vfat.txt
+++ b/Documentation/filesystems/vfat.txt
@@ -102,7 +102,7 @@ shortname=lower|win95|winnt|mixed
                 winnt: emulate the Windows NT rule for display/create.
                 mixed: emulate the Windows NT rule for display,
                        emulate the Windows 95 rule for create.
-                 Default setting is `lower'.
+                 Default setting is `mixed'.
 tz=UTC        -- Interpret timestamps as UTC rather than local time.
                 This option disables the conversion of timestamps
diff --git a/Documentation/hwmon/ltc4215 b/Documentation/hwmon/ltc4215
index 2e6a21eb656c..c196a1846259 100644
--- a/Documentation/hwmon/ltc4215
+++ b/Documentation/hwmon/ltc4215
@@ -22,12 +22,13 @@ Usage Notes
 -----------
 This driver does not probe for LTC4215 devices, due to the fact that some
-of the possible addresses are unfriendly to probing. You will need to use
+of the possible addresses are unfriendly to probing. You will have to
-the "force" parameter to tell the driver where to find the device.
+instantiate the devices explicitly.
 Example: the following will load the driver for an LTC4215 at address 0x44
 on I2C bus #0:
-$ modprobe ltc4215 force=0,0x44
+$ modprobe ltc4215
+$ echo ltc4215 0x44 > /sys/bus/i2c/devices/i2c-0/new_device
 Sysfs entries
diff --git a/Documentation/hwmon/ltc4245 b/Documentation/hwmon/ltc4245
index bae7a3adc5d8..02838a47d862 100644
--- a/Documentation/hwmon/ltc4245
+++ b/Documentation/hwmon/ltc4245
@@ -23,12 +23,13 @@ Usage Notes
 -----------
 This driver does not probe for LTC4245 devices, due to the fact that some
-of the possible addresses are unfriendly to probing. You will need to use
+of the possible addresses are unfriendly to probing. You will have to
-the "force" parameter to tell the driver where to find the device.
+instantiate the devices explicitly.
 Example: the following will load the driver for an LTC4245 at address 0x23
 on I2C bus #1:
-$ modprobe ltc4245 force=1,0x23
+$ modprobe ltc4245
+$ echo ltc4245 0x23 > /sys/bus/i2c/devices/i2c-1/new_device
 Sysfs entries
diff --git a/Documentation/i2c/instantiating-devices b/Documentation/i2c/instantiating-devices
index c740b7b41088..e89490270aba 100644
--- a/Documentation/i2c/instantiating-devices
+++ b/Documentation/i2c/instantiating-devices
@@ -188,7 +188,7 @@ segment, the address is sufficient to uniquely identify the device to be
 deleted.
 Example:
-# echo eeprom 0x50 > /sys/class/i2c-adapter/i2c-3/new_device
+# echo eeprom 0x50 > /sys/bus/i2c/devices/i2c-3/new_device
 While this interface should only be used when in-kernel device declaration
 can't be done, there is a variety of cases where it can be helpful:
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 6fa7292947e5..9107b387e91f 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -671,6 +671,7 @@ and is between 256 and 4096 characters. It is defined in the file
        earlyprintk=    [X86,SH,BLACKFIN]
                        earlyprintk=vga
                        earlyprintk=serial[,ttySn[,baudrate]]
+                        earlyprintk=ttySn[,baudrate]
                        earlyprintk=dbgp[debugController#]
                        Append ",keep" to not disable it when the real console
diff --git a/Documentation/laptops/thinkpad-acpi.txt b/Documentation/laptops/thinkpad-acpi.txt
index 6d03487ef1c7..aafcaa634191 100644
--- a/Documentation/laptops/thinkpad-acpi.txt
+++ b/Documentation/laptops/thinkpad-acpi.txt
@@ -199,18 +199,22 @@ kind to allow it (and it often doesn't!).
 Not all bits in the mask can be modified.  Not all bits that can be
 modified do anything.  Not all hot keys can be individually controlled
-by the mask.  Some models do not support the mask at all, and in those
+by the mask.  Some models do not support the mask at all.  The behaviour
-models, hot keys cannot be controlled individually.  The behaviour of
+of the mask is, therefore, highly dependent on the ThinkPad model.
-the mask is, therefore, highly dependent on the ThinkPad model.
+The driver will filter out any unmasked hotkeys, so even if the firmware
+doesn't allow disabling an specific hotkey, the driver will not report
+events for unmasked hotkeys.
 Note that unmasking some keys prevents their default behavior.  For
 example, if Fn+F5 is unmasked, that key will no longer enable/disable
-Bluetooth by itself.
+Bluetooth by itself in firmware.
-Note also that not all Fn key combinations are supported through ACPI.
+Note also that not all Fn key combinations are supported through ACPI
-For example, on the X40, the brightness, volume and "Access IBM" buttons
+depending on the ThinkPad model and firmware version.  On those
-do not generate ACPI events even with this driver.  They *can* be used
+ThinkPads, it is still possible to support some extra hotkeys by
-through the "ThinkPad Buttons" utility, see http://www.nongnu.org/tpb/
+polling the "CMOS NVRAM" at least 10 times per second.  The driver
+attempts to enables this functionality automatically when required.
 procfs notes:
@@ -255,18 +259,11 @@ sysfs notes:
                1: does nothing
        hotkey_mask:
-                bit mask to enable driver-handling (and depending on
+                bit mask to enable reporting (and depending on
                the firmware, ACPI event generation) for each hot key
                (see above).  Returns the current status of the hot keys
                mask, and allows one to modify it.
-                Note: when NVRAM polling is active, the firmware mask
-                will be different from the value returned by
-                hotkey_mask.  The driver will retain enabled bits for
-                hotkeys that are under NVRAM polling even if the
-                firmware refuses them, and will not set these bits on
-                the firmware hot key mask.
        hotkey_all_mask:
                bit mask that should enable event reporting for all
                supported hot keys, when echoed to hotkey_mask above.
@@ -279,7 +276,8 @@ sysfs notes:
                bit mask that should enable event reporting for all
                supported hot keys, except those which are always
                handled by the firmware anyway.  Echo it to
-                hotkey_mask above, to use.
+                hotkey_mask above, to use.  This is the default mask
+                used by the driver.
        hotkey_source_mask:
                bit mask that selects which hot keys will the driver
@@ -287,9 +285,10 @@ sysfs notes:
                based on the capabilities reported by the ACPI firmware,
                but it can be overridden at runtime.
-                Hot keys whose bits are set in both hotkey_source_mask
+                Hot keys whose bits are set in hotkey_source_mask are
-                and also on hotkey_mask are polled for in NVRAM.  Only a
+                polled for in NVRAM, and reported as hotkey events if
-                few hot keys are available through CMOS NVRAM polling.
+                enabled in hotkey_mask.  Only a few hot keys are
+                available through CMOS NVRAM polling.
                Warning: when in NVRAM mode, the volume up/down/mute
                keys are synthesized according to changes in the mixer,
@@ -525,6 +524,7 @@ compatibility purposes when hotkey_report_mode is set to 1.
 0x2305          System is waking up from suspend to eject bay
 0x2404          System is waking up from hibernation to undock
 0x2405          System is waking up from hibernation to eject bay
+0x5010          Brightness level changed/control event
 The above events are never propagated by the driver.
@@ -532,7 +532,6 @@ The above events are never propagated by the driver.
 0x4003          Undocked (see 0x2x04), can sleep again
 0x500B          Tablet pen inserted into its storage bay
 0x500C          Tablet pen removed from its storage bay
-0x5010          Brightness level changed (newer Lenovo BIOSes)
 The above events are propagated by the driver.
@@ -621,6 +620,8 @@ For Lenovo models *with* ACPI backlight control:
 2. Do *NOT* load up ACPI video, enable the hotkeys in thinkpad-acpi,
   and map them to KEY_BRIGHTNESS_UP and KEY_BRIGHTNESS_DOWN.  Process
   these keys on userspace somehow (e.g. by calling xbacklight).
+   The driver will do this automatically if it detects that ACPI video
+   has been disabled.
 Bluetooth
@@ -1459,3 +1460,8 @@ Sysfs interface changelog:
 0x020400:       Marker for 16 LEDs support.  Also, LEDs that are known
                to not exist in a given model are not registered with
                the LED sysfs class anymore.
+0x020500:       Updated hotkey driver, hotkey_mask is always available
+                and it is always able to disable hot keys.  Very old
+                thinkpads are properly supported.  hotkey_bios_mask
+                is deprecated and marked for removal.
diff --git a/Documentation/i2c/chips/eeprom b/Documentation/misc-devices/eeprom
index f7e8104b5764..f7e8104b5764 100644
--- a/Documentation/i2c/chips/eeprom
+++ b/Documentation/misc-devices/eeprom
diff --git a/Documentation/i2c/chips/max6875 b/Documentation/misc-devices/max6875
index 10ca43cd1a72..1e89ee3ccc1b 100644
--- a/Documentation/i2c/chips/max6875
+++ b/Documentation/misc-devices/max6875
@@ -42,10 +42,12 @@ General Remarks
 Valid addresses for the MAX6875 are 0x50 and 0x52.
 Valid addresses for the MAX6874 are 0x50, 0x52, 0x54 and 0x56.
-The driver does not probe any address, so you must force the address.
+The driver does not probe any address, so you explicitly instantiate the
+devices.
 Example:
-$ modprobe max6875 force=0,0x50
+$ modprobe max6875
+$ echo max6875 0x50 > /sys/bus/i2c/devices/i2c-0/new_device
 The MAX6874/MAX6875 ignores address bit 0, so this driver attaches to multiple
 addresses.  For example, for address 0x50, it also reserves 0x51.
diff --git a/Documentation/sound/alsa/HD-Audio-Models.txt b/Documentation/sound/alsa/HD-Audio-Models.txt
index f1708b79f963..75fddb40f416 100644
--- a/Documentation/sound/alsa/HD-Audio-Models.txt
+++ b/Documentation/sound/alsa/HD-Audio-Models.txt
@@ -209,6 +209,7 @@ AD1884A / AD1883 / AD1984A / AD1984B
  laptop        laptop with HP jack sensing
  mobile        mobile devices with HP jack sensing
  thinkpad      Lenovo Thinkpad X300
+  touchsmart    HP Touchsmart
 AD1884
 ======
diff --git a/Documentation/vm/ksm.txt b/Documentation/vm/ksm.txt
index 72a22f65960e..262d8e6793a3 100644
--- a/Documentation/vm/ksm.txt
+++ b/Documentation/vm/ksm.txt
@@ -52,15 +52,15 @@ The KSM daemon is controlled by sysfs files in /sys/kernel/mm/ksm/,
 readable by all but writable only by root:
 max_kernel_pages - set to maximum number of kernel pages that KSM may use
-                   e.g. "echo 2000 > /sys/kernel/mm/ksm/max_kernel_pages"
+                   e.g. "echo 100000 > /sys/kernel/mm/ksm/max_kernel_pages"
                   Value 0 imposes no limit on the kernel pages KSM may use;
                   but note that any process using MADV_MERGEABLE can cause
                   KSM to allocate these pages, unswappable until it exits.
-                   Default: 2000 (chosen for demonstration purposes)
+                   Default: quarter of memory (chosen to not pin too much)
 pages_to_scan    - how many present pages to scan before ksmd goes to sleep
-                   e.g. "echo 200 > /sys/kernel/mm/ksm/pages_to_scan"
+                   e.g. "echo 100 > /sys/kernel/mm/ksm/pages_to_scan"
-                   Default: 200 (chosen for demonstration purposes)
+                   Default: 100 (chosen for demonstration purposes)
 sleep_millisecs  - how many milliseconds ksmd should sleep before next scan
                   e.g. "echo 20 > /sys/kernel/mm/ksm/sleep_millisecs"
@@ -70,7 +70,8 @@ run              - set 0 to stop ksmd from running but keep merged pages,
                   set 1 to run ksmd e.g. "echo 1 > /sys/kernel/mm/ksm/run",
                   set 2 to stop ksmd and unmerge all pages currently merged,
                         but leave mergeable areas registered for next run
-                   Default: 1 (for immediate use by apps which register)
+                   Default: 0 (must be changed to 1 to activate KSM,
+                               except if CONFIG_SYSFS is disabled)
 The effectiveness of KSM and MADV_MERGEABLE is shown in /sys/kernel/mm/ksm/:
@@ -86,4 +87,4 @@ pages_volatile embraces several different kinds of activity, but a high
 proportion there would also indicate poor use of madvise MADV_MERGEABLE.
 Izik Eidus,
-Hugh Dickins, 30 July 2009
+Hugh Dickins, 24 Sept 2009
diff --git a/Documentation/vm/page-types.c b/Documentation/vm/page-types.c
index fa1a30d9e9d5..3ec4f2a22585 100644
--- a/Documentation/vm/page-types.c
+++ b/Documentation/vm/page-types.c
@@ -2,7 +2,10 @@
 * page-types: Tool for querying page flags
 *
 * Copyright (C) 2009 Intel corporation
- * Copyright (C) 2009 Wu Fengguang <fengguang.wu@intel.com>
+ *
+ * Authors: Wu Fengguang <fengguang.wu@intel.com>
+ *
+ * Released under the General Public License (GPL).
 */
 #define _LARGEFILE64_SOURCE
@@ -69,7 +72,9 @@
 #define KPF_COMPOUND_TAIL       16
 #define KPF_HUGE                17
 #define KPF_UNEVICTABLE         18
+#define KPF_HWPOISON            19
 #define KPF_NOPAGE              20
+#define KPF_KSM                 21
 /* [32-] kernel hacking assistances */
 #define KPF_RESERVED            32
@@ -116,7 +121,9 @@ static char *page_flag_names[] = {
        [KPF_COMPOUND_TAIL]     = "T:compound_tail",
        [KPF_HUGE]              = "G:huge",
        [KPF_UNEVICTABLE]       = "u:unevictable",
+        [KPF_HWPOISON]          = "X:hwpoison",
        [KPF_NOPAGE]            = "n:nopage",
+        [KPF_KSM]               = "x:ksm",
        [KPF_RESERVED]          = "r:reserved",
        [KPF_MLOCKED]           = "m:mlocked",
@@ -152,9 +159,6 @@ static unsigned long	opt_size[MAX_ADDR_RANGES];
 static int              nr_vmas;
 static unsigned long    pg_start[MAX_VMAS];
 static unsigned long    pg_end[MAX_VMAS];
-static unsigned long    voffset;
-static int              pagemap_fd;
 #define MAX_BIT_FILTERS 64
 static int              nr_bit_filters;
@@ -163,9 +167,16 @@ static uint64_t		opt_bits[MAX_BIT_FILTERS];
 static int              page_size;
-#define PAGES_BATCH     (64 << 10)      /* 64k pages */
+static int              pagemap_fd;
 static int              kpageflags_fd;
+static int              opt_hwpoison;
+static int              opt_unpoison;
+static char             *hwpoison_debug_fs = "/debug/hwpoison";
+static int              hwpoison_inject_fd;
+static int              hwpoison_forget_fd;
 #define HASH_SHIFT      13
 #define HASH_SIZE       (1 << HASH_SHIFT)
 #define HASH_MASK       (HASH_SIZE - 1)
@@ -207,6 +218,74 @@ static void fatal(const char *x, ...)
        exit(EXIT_FAILURE);
 }
+int checked_open(const char *pathname, int flags)
+{
+        int fd = open(pathname, flags);
+        if (fd < 0) {
+                perror(pathname);
+                exit(EXIT_FAILURE);
+        }
+        return fd;
+}
+/*
+ * pagemap/kpageflags routines
+ */
+static unsigned long do_u64_read(int fd, char *name,
+                                 uint64_t *buf,
+                                 unsigned long index,
+                                 unsigned long count)
+{
+        long bytes;
+        if (index > ULONG_MAX / 8)
+                fatal("index overflow: %lu\n", index);
+        if (lseek(fd, index * 8, SEEK_SET) < 0) {
+                perror(name);
+                exit(EXIT_FAILURE);
+        }
+        bytes = read(fd, buf, count * 8);
+        if (bytes < 0) {
+                perror(name);
+                exit(EXIT_FAILURE);
+        }
+        if (bytes % 8)
+                fatal("partial read: %lu bytes\n", bytes);
+        return bytes / 8;
+}
+static unsigned long kpageflags_read(uint64_t *buf,
+                                     unsigned long index,
+                                     unsigned long pages)
+{
+        return do_u64_read(kpageflags_fd, PROC_KPAGEFLAGS, buf, index, pages);
+}
+static unsigned long pagemap_read(uint64_t *buf,
+                                  unsigned long index,
+                                  unsigned long pages)
+{
+        return do_u64_read(pagemap_fd, "/proc/pid/pagemap", buf, index, pages);
+}
+static unsigned long pagemap_pfn(uint64_t val)
+{
+        unsigned long pfn;
+        if (val & PM_PRESENT)
+                pfn = PM_PFRAME(val);
+        else
+                pfn = 0;
+        return pfn;
+}
 /*
 * page flag names
@@ -255,7 +334,8 @@ static char *page_flag_longname(uint64_t flags)
 * page list and summary
 */
-static void show_page_range(unsigned long offset, uint64_t flags)
+static void show_page_range(unsigned long voffset,
+                            unsigned long offset, uint64_t flags)
 {
        static uint64_t      flags0;
        static unsigned long voff;
@@ -281,7 +361,8 @@ static void show_page_range(unsigned long offset, uint64_t flags)
        count  = 1;
 }
-static void show_page(unsigned long offset, uint64_t flags)
+static void show_page(unsigned long voffset,
+                      unsigned long offset, uint64_t flags)
 {
        if (opt_pid)
                printf("%lx\t", voffset);
@@ -362,6 +443,62 @@ static uint64_t well_known_flags(uint64_t flags)
        return flags;
 }
+static uint64_t kpageflags_flags(uint64_t flags)
+{
+        flags = expand_overloaded_flags(flags);
+        if (!opt_raw)
+                flags = well_known_flags(flags);
+        return flags;
+}
+/*
+ * page actions
+ */
+static void prepare_hwpoison_fd(void)
+{
+        char buf[100];
+        if (opt_hwpoison && !hwpoison_inject_fd) {
+                sprintf(buf, "%s/corrupt-pfn", hwpoison_debug_fs);
+                hwpoison_inject_fd = checked_open(buf, O_WRONLY);
+        }
+        if (opt_unpoison && !hwpoison_forget_fd) {
+                sprintf(buf, "%s/renew-pfn", hwpoison_debug_fs);
+                hwpoison_forget_fd = checked_open(buf, O_WRONLY);
+        }
+}
+static int hwpoison_page(unsigned long offset)
+{
+        char buf[100];
+        int len;
+        len = sprintf(buf, "0x%lx\n", offset);
+        len = write(hwpoison_inject_fd, buf, len);
+        if (len < 0) {
+                perror("hwpoison inject");
+                return len;
+        }
+        return 0;
+}
+static int unpoison_page(unsigned long offset)
+{
+        char buf[100];
+        int len;
+        len = sprintf(buf, "0x%lx\n", offset);
+        len = write(hwpoison_forget_fd, buf, len);
+        if (len < 0) {
+                perror("hwpoison forget");
+                return len;
+        }
+        return 0;
+}
 /*
 * page frame walker
@@ -394,104 +531,83 @@ static int hash_slot(uint64_t flags)
        exit(EXIT_FAILURE);
 }
-static void add_page(unsigned long offset, uint64_t flags)
+static void add_page(unsigned long voffset,
+                     unsigned long offset, uint64_t flags)
 {
-        flags = expand_overloaded_flags(flags);
+        flags = kpageflags_flags(flags);
-        if (!opt_raw)
-                flags = well_known_flags(flags);
        if (!bit_mask_ok(flags))
                return;
+        if (opt_hwpoison)
+                hwpoison_page(offset);
+        if (opt_unpoison)
+                unpoison_page(offset);
        if (opt_list == 1)
-                show_page_range(offset, flags);
+                show_page_range(voffset, offset, flags);
        else if (opt_list == 2)
-                show_page(offset, flags);
+                show_page(voffset, offset, flags);
        nr_pages[hash_slot(flags)]++;
        total_pages++;
 }
-static void walk_pfn(unsigned long index, unsigned long count)
+#define KPAGEFLAGS_BATCH        (64 << 10)      /* 64k pages */
+static void walk_pfn(unsigned long voffset,
+                     unsigned long index,
+                     unsigned long count)
 {
+        uint64_t buf[KPAGEFLAGS_BATCH];
        unsigned long batch;
-        unsigned long n;
+        unsigned long pages;
        unsigned long i;
-        if (index > ULONG_MAX / KPF_BYTES)
-                fatal("index overflow: %lu\n", index);
-        lseek(kpageflags_fd, index * KPF_BYTES, SEEK_SET);
        while (count) {
-                uint64_t kpageflags_buf[KPF_BYTES * PAGES_BATCH];
+                batch = min_t(unsigned long, count, KPAGEFLAGS_BATCH);
+                pages = kpageflags_read(buf, index, batch);
-                batch = min_t(unsigned long, count, PAGES_BATCH);
+                if (pages == 0)
-                n = read(kpageflags_fd, kpageflags_buf, batch * KPF_BYTES);
-                if (n == 0)
                        break;
-                if (n < 0) {
-                        perror(PROC_KPAGEFLAGS);
-                        exit(EXIT_FAILURE);
-                }
-                if (n % KPF_BYTES != 0)
+                for (i = 0; i < pages; i++)
-                        fatal("partial read: %lu bytes\n", n);
+                        add_page(voffset + i, index + i, buf[i]);
-                n = n / KPF_BYTES;
-                for (i = 0; i < n; i++)
+                index += pages;
-                        add_page(index + i, kpageflags_buf[i]);
+                count -= pages;
-                index += batch;
-                count -= batch;
        }
 }
+#define PAGEMAP_BATCH   (64 << 10)
-#define PAGEMAP_BATCH   4096
+static void walk_vma(unsigned long index, unsigned long count)
-static unsigned long task_pfn(unsigned long pgoff)
 {
-        static uint64_t buf[PAGEMAP_BATCH];
+        uint64_t buf[PAGEMAP_BATCH];
-        static unsigned long start;
+        unsigned long batch;
-        static long count;
+        unsigned long pages;
-        uint64_t pfn;
+        unsigned long pfn;
+        unsigned long i;
-        if (pgoff < start || pgoff >= start + count) {
+        while (count) {
-                if (lseek64(pagemap_fd,
+                batch = min_t(unsigned long, count, PAGEMAP_BATCH);
-                            (uint64_t)pgoff * PM_ENTRY_BYTES,
+                pages = pagemap_read(buf, index, batch);
-                            SEEK_SET) < 0) {
+                if (pages == 0)
-                        perror("pagemap seek");
+                        break;
-                        exit(EXIT_FAILURE);
-                }
-                count = read(pagemap_fd, buf, sizeof(buf));
-                if (count == 0)
-                        return 0;
-                if (count < 0) {
-                        perror("pagemap read");
-                        exit(EXIT_FAILURE);
-                }
-                if (count % PM_ENTRY_BYTES) {
-                        fatal("pagemap read not aligned.\n");
-                        exit(EXIT_FAILURE);
-                }
-                count /= PM_ENTRY_BYTES;
-                start = pgoff;
-        }
-        pfn = buf[pgoff - start];
+                for (i = 0; i < pages; i++) {
-        if (pfn & PM_PRESENT)
+                        pfn = pagemap_pfn(buf[i]);
-                pfn = PM_PFRAME(pfn);
+                        if (pfn)
-        else
+                                walk_pfn(index + i, pfn, 1);
-                pfn = 0;
+                }
-        return pfn;
+                index += pages;
+                count -= pages;
+        }
 }
 static void walk_task(unsigned long index, unsigned long count)
 {
-        int i = 0;
        const unsigned long end = index + count;
+        unsigned long start;
+        int i = 0;
        while (index < end) {
@@ -501,15 +617,11 @@ static void walk_task(unsigned long index, unsigned long count)
                if (pg_start[i] >= end)
                        return;
-                voffset = max_t(unsigned long, pg_start[i], index);
+                start = max_t(unsigned long, pg_start[i], index);
-                index   = min_t(unsigned long, pg_end[i], end);
+                index = min_t(unsigned long, pg_end[i], end);
-                assert(voffset < index);
+                assert(start < index);
-                for (; voffset < index; voffset++) {
+                walk_vma(start, index - start);
-                        unsigned long pfn = task_pfn(voffset);
-                        if (pfn)
-                                walk_pfn(pfn, 1);
-                }
        }
 }
@@ -527,18 +639,14 @@ static void walk_addr_ranges(void)
 {
        int i;
-        kpageflags_fd = open(PROC_KPAGEFLAGS, O_RDONLY);
+        kpageflags_fd = checked_open(PROC_KPAGEFLAGS, O_RDONLY);
-        if (kpageflags_fd < 0) {
-                perror(PROC_KPAGEFLAGS);
-                exit(EXIT_FAILURE);
-        }
        if (!nr_addr_ranges)
                add_addr_range(0, ULONG_MAX);
        for (i = 0; i < nr_addr_ranges; i++)
                if (!opt_pid)
-                        walk_pfn(opt_offset[i], opt_size[i]);
+                        walk_pfn(0, opt_offset[i], opt_size[i]);
                else
                        walk_task(opt_offset[i], opt_size[i]);
@@ -575,6 +683,8 @@ static void usage(void)
 "            -l|--list                 Show page details in ranges\n"
 "            -L|--list-each            Show page details one by one\n"
 "            -N|--no-summary           Don't show summay info\n"
+"            -X|--hwpoison             hwpoison pages\n"
+"            -x|--unpoison             unpoison pages\n"
 "            -h|--help                 Show this usage message\n"
 "addr-spec:\n"
 "            N                         one page at offset N (unit: pages)\n"
@@ -624,11 +734,7 @@ static void parse_pid(const char *str)
        opt_pid = parse_number(str);
        sprintf(buf, "/proc/%d/pagemap", opt_pid);
-        pagemap_fd = open(buf, O_RDONLY);
+        pagemap_fd = checked_open(buf, O_RDONLY);
-        if (pagemap_fd < 0) {
-                perror(buf);
-                exit(EXIT_FAILURE);
-        }
        sprintf(buf, "/proc/%d/maps", opt_pid);
        file = fopen(buf, "r");
@@ -788,6 +894,8 @@ static struct option opts[] = {
        { "list"      , 0, NULL, 'l' },
        { "list-each" , 0, NULL, 'L' },
        { "no-summary", 0, NULL, 'N' },
+        { "hwpoison"  , 0, NULL, 'X' },
+        { "unpoison"  , 0, NULL, 'x' },
        { "help"      , 0, NULL, 'h' },
        { NULL        , 0, NULL, 0 }
 };
@@ -799,7 +907,7 @@ int main(int argc, char *argv[])
        page_size = getpagesize();
        while ((c = getopt_long(argc, argv,
-                                "rp:f:a:b:lLNh", opts, NULL)) != -1) {
+                                "rp:f:a:b:lLNXxh", opts, NULL)) != -1) {
                switch (c) {
                case 'r':
                        opt_raw = 1;
@@ -825,6 +933,14 @@ int main(int argc, char *argv[])
                case 'N':
                        opt_no_summary = 1;
                        break;
+                case 'X':
+                        opt_hwpoison = 1;
+                        prepare_hwpoison_fd();
+                        break;
+                case 'x':
+                        opt_unpoison = 1;
+                        prepare_hwpoison_fd();
+                        break;
                case 'h':
                        usage();
                        exit(0);
@@ -844,7 +960,7 @@ int main(int argc, char *argv[])
        walk_addr_ranges();
        if (opt_list == 1)
-                show_page_range(0, 0);  /* drain the buffer */
+                show_page_range(0, 0, 0);  /* drain the buffer */
        if (opt_no_summary)
                return 0;
diff --git a/Documentation/vm/pagemap.txt b/Documentation/vm/pagemap.txt
index 600a304a828c..df09b9650a81 100644
--- a/Documentation/vm/pagemap.txt
+++ b/Documentation/vm/pagemap.txt
@@ -57,7 +57,9 @@ There are three components to pagemap:
    16. COMPOUND_TAIL
    16. HUGE
    18. UNEVICTABLE
+    19. HWPOISON
    20. NOPAGE
+    21. KSM
 Short descriptions to the page flags:
@@ -86,9 +88,15 @@ Short descriptions to the page flags:
 17. HUGE
    this is an integral part of a HugeTLB page
+19. HWPOISON
+    hardware detected memory corruption on this page: don't touch the data!
 20. NOPAGE
    no page frame exists at the requested address
+21. KSM
+    identical memory pages dynamically shared between one or more processes
    [IO related page flags]
 1. ERROR     IO error occurred
 3. UPTODATE  page has up-to-date data
diff --git a/Documentation/w1/masters/ds2482 b/Documentation/w1/masters/ds2482
index 9210d6fa5024..299b91c7609f 100644
--- a/Documentation/w1/masters/ds2482
+++ b/Documentation/w1/masters/ds2482
@@ -24,8 +24,8 @@ General Remarks
 Valid addresses are 0x18, 0x19, 0x1a, and 0x1b.
 However, the device cannot be detected without writing to the i2c bus, so no
-detection is done.
+detection is done. You should instantiate the device explicitly.
-You should force the device address.
-$ modprobe ds2482 force=0,0x18
+$ modprobe ds2482
+$ echo ds2482 0x18 > /sys/bus/i2c/devices/i2c-0/new_device