diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/SubmittingPatches | 2 | ||||
| -rw-r--r-- | Documentation/arm/tcm.txt | 145 | ||||
| -rw-r--r-- | Documentation/filesystems/ext4.txt | 13 | ||||
| -rw-r--r-- | Documentation/filesystems/proc.txt | 1 | ||||
| -rw-r--r-- | Documentation/filesystems/vfat.txt | 2 | ||||
| -rw-r--r-- | Documentation/laptops/thinkpad-acpi.txt | 48 |
6 files changed, 184 insertions, 27 deletions
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..074f4be6667f --- /dev/null +++ b/Documentation/arm/tcm.txt @@ -0,0 +1,145 @@ +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 exists totally outside the MMU and will +override any MMU mappings. + +Code executing inside the ITCM does not "see" any MMU mappings +and e.g. register accesses must be made to physical addresses. + +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/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 - when data is copied from user to page cache. + +delalloc (*) Defer block allocation until just before ext4 + 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/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 -models, hot keys cannot be controlled individually. The behaviour of -the mask is, therefore, highly dependent on the ThinkPad model. +by the mask. Some models do not support the mask at all. The behaviour +of 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. -For example, on the X40, the brightness, volume and "Access IBM" buttons -do not generate ACPI events even with this driver. They *can* be used -through the "ThinkPad Buttons" utility, see http://www.nongnu.org/tpb/ +Note also that not all Fn key combinations are supported through ACPI +depending on the ThinkPad model and firmware version. On those +ThinkPads, it is still possible to support some extra hotkeys by +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 - and also on hotkey_mask are polled for in NVRAM. Only a - few hot keys are available through CMOS NVRAM polling. + Hot keys whose bits are set in hotkey_source_mask are + polled for in NVRAM, and reported as hotkey events if + 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. |
