This updates the F00F bug workaround code to the IDT changes in the TLS
patch.

Tested it on a non-Pentium box on which i triggered the workaround
artificially.

This fixes the ACPI_DEBUG compile issue that turned up.

  + cleanup init.c and split into pgtable.c
  + split declaration of _text, _etext outside into sections.h

Add irq_enter/exit to smp_call_function_interrupt():
arch/i386/kernel/microcode.c:do_microcode_update() calls
smp_call_function(do_update_one).  do_update_one() does
spin_lock/unlock.

Remove unneeded GET_THREAD_INFO(%ebx) in device_not_available() trap in
entry.S

At least it compiles now.

interrupt probing

This is no better or worse than the cli/sti the cmd640 driver
used to have, but at least it compiles and works in the new
scheme of things.

Perfection can wait. Especially since that probably involves
removing the PCI-related code, and just trusting the native
Linux direct PCI accesses.

into penguin.transmeta.com:/home/penguin/torvalds/repositories/kernel/linux

the following patch implements proper x86 TLS support in the Linux kernel,
via a new system-call, sys_set_thread_area():

   http://redhat.com/~mingo/tls-patches/tls-2.5.28-C6

a TLS test utility can be downloaded from:

    http://redhat.com/~mingo/tls-patches/tls_test.c

what is TLS? Thread Local Storage is a concept used by threading
abstractions - fast an efficient way to store per-thread local (but not
on-stack local) data. The __thread extension is already supported by gcc.

proper TLS support in compilers (and glibc/pthreads) is a bit problematic
on the x86 platform. There's only 8 general purpose registers available,
so on x86 we have to use segments to access the TLS. The approach used by
glibc so far was to set up a per-thread LDT entry to describe the TLS.
Besides the generic unrobustness of LDTs, this also introduced a limit:
the maximum number of LDT entries is 8192, so the maximum number of
threads per application is 8192.

this patch does it differently - the kernel keeps a specific per-thread
GDT entry that can be set up and modified by each thread:

     asmlinkage int sys_set_thread_area(unsigned int base,
               unsigned int limit, unsigned int flags)

the kernel, upon context-switch, modifies this GDT entry to match that of
the thread's TLS setting. This way user-space threaded code can access
per-thread data via this descriptor - by using the same, constant %gs (or
%gs) selector. The number of TLS areas is unlimited, and there is no
additional allocation overhead associated with TLS support.


the biggest problem preventing the introduction of this concept was
Linux's global shared GDT on SMP systems. The patch fixes this by
implementing a per-CPU GDT, which is also a nice context-switch speedup,
2-task lat_ctx context-switching got faster by about 5% on a dual Celeron
testbox. [ Could it be that a shared GDT is fundamentally suboptimal on
SMP? perhaps updating the 'accessed' bit in the DS/CS descriptors causes
some sort locked memory cycle overhead? ]

the GDT layout got simplified:

 *   0 - null
 *   1 - Thread-Local Storage (TLS) segment
 *   2 - kernel code segment
 *   3 - kernel data segment
 *   4 - user code segment              <==== new cacheline
 *   5 - user data segment
 *   6 - TSS
 *   7 - LDT
 *   8 - APM BIOS support               <==== new cacheline
 *   9 - APM BIOS support
 *  10 - APM BIOS support
 *  11 - APM BIOS support
 *  12 - PNPBIOS support                <==== new cacheline
 *  13 - PNPBIOS support
 *  14 - PNPBIOS support
 *  15 - PNPBIOS support
 *  16 - PNPBIOS support                <==== new cacheline
 *  17 - not used
 *  18 - not used
 *  19 - not used

set_thread_area() currently recognizes the following flags:

  #define TLS_FLAG_LIMIT_IN_PAGES         0x00000001
  #define TLS_FLAG_WRITABLE               0x00000002
  #define TLS_FLAG_CLEAR                  0x00000004

- in theory we could avoid the 'limit in pages' bit, but i wanted to
  preserve the flexibility to potentially enable the setting of
  byte-granularity stack segments for example. And unlimited segments
  (granularity = pages, limit = 0xfffff) might have a performance
  advantage on some CPUs. We could also automatically figure out the best
  possible granularity for a given limit - but i wanted to avoid this kind
  of guesswork. Some CPUs might have a plus for page-limit segments - who
  knows.

- The 'writable' flag is straightforward and could be useful to some
  applications.

- The 'clear' flag clears the TLS. [note that a base 0 limit 0 TLS is in
  fact legal, it's a single-byte segment at address 0.]

(the system-call does not expose any other segment options to user-space,
priviledge level is 3, the segment is 32-bit, etc. - it's using safe and
sane defaults.)

NOTE: the interface does not allow the changing of the TLS of another
thread on purpose - that would just complicate the interface (and
implementation) unnecesserily. Is there any good reason to allow the
setting of another thread's TLS?

NOTE2: non-pthreads glibc applications can call set_thread_area() to set
up a GDT entry just below the end of stack. We could use some sort of
default TLS area as well, but that would hard-code a given segment.

Removed unused targets to CHMOD_FILES in scripts

This allow a fresh kernel to start the build process without
bailing about docgen.

Fix panic in EC driver (Dom B)
Add a some more sanity checking (Richard Schaal)

A much needed (and widely tested) ACPI bugfix for kernel 2.5.28:
An u8 was casted into an u32, then all 32 bits were zeroed. This can cause
other values, e.g. "unsigned long flags" to be corrupted. When these
flags==0 are "restored", the system locks hard.

into osdl.org:/home/mochel/src/kernel/devel/linux-2.5-driverfs-rewrite

These are tied together a bit, so they're included in the same patch

Mainly, they move the taking of the inode's i_sem into the unlink and rmdir. 

driverfs_rmdir doesn't call driverfs_unlink anymore, as it checks if the directory is empty
and conditionally does d_delete on it.

fs/namei.c implements d_unhash, which is called in vfs_rmdir. This isn't exported (yet), 
so reimplement it here (at least until it's known that it's not needed or it's exported).

Add check for existence of dentry in driverfs_symlink and driverfs_mknod  (which the other creation
functions use).

Call driverfs_mkdir directly, instead of going through vfs.

This is the first of a series of patches to driverfs to _not_ use the vfs layer for file creation
and deletion. 
The VFS layer is allowing files and directories to be removed from userspace, which we don't want 
at all. 

Per Al Viro's suggesting, I am pushing the necessary checks from the vfs_* functions into the 
driverfs functions, and calling them directly from the kernel interface to driverfs.

This is the first, for file creation

into home.transmeta.com:/home/torvalds/v2.5/linux

The rewritten makefile for DocBook requires that working directory
is $(TOPDIR) therefore use -f Documentation/DocBook/Makefile to
invoke the docbook makefile.

To support the new DocBook makefile the script target needs to be located
the block that is checked for precense of a .config file.

kernel-doc-nano-HOWTO.txt updated to reflect new functionality
provided by docproc.
gen-all-syms and docgen description removed.
kernel-api.tmpl and parportbook.tmpl updated to specify files to search
for EXPORT-SYMBOL* to enable documentation of all relevant functions.

Massive cleanup of makefile.
Comments added as well.
Enabled by the new functionality provided by docproc
When generating HTML locate a new file in DocBook dir that points to
the book in question.

This is the first patch in a serie to clean-up the DocBook
Makefile.

docproc is extented to include the functionality previously provided by
gen-all-syms and docgen.  Furthermore the necessity to specify which
files to search for EXPORT_SYMBOL are removed, the information is now
read in the .tmpl files.

docproc is furthermore extended to generate dependency information.
gen-all-syms and docgen are deleted.

During processing of skbuff.h three warnings were issued,
because members of an enum within a struct were nor documented.
This patch fixes kernel-doc not to spit out these non-valid warnings.
Originally by Thunder.

Forward port from 2.4, originally by Alan Cox
 o Do not generate empty RefEntry's
 o Improved error reporting

Forward port from 2.4, originally by Christoph Hellwig

 o Changed targets in documentation/DocBook/Makefile
 o New filenames in DocBook/kernel-api.tmpl

This removes cli/sti from SPX registration code in IPX.  I decided to
use normal rw_semaphore instead of net_family_{write,read}_{lock,unlock}
used in net/socket.c.

I left SPX code itself alone: I do not use it and last time I checked it
it was very unreliable reliable transport.

This patch for 2.5.28 fixes two explicit accesses to thread_info->cpu
in generic code to use the new UP-optimised macros instead.

This patch for 2.5.28 reduces the stack frame size of
arch/i386/kernel/nmi.c:check_nmi_watchdog() from 4096 bytes
in the worst case to 128 bytes.

The problem with the current code is that it copies the entire
irq_stat[] array, when only a single field (__nmi_count) is of
interest. The irq_stat_t element type is only 28 bytes, but it
is also ____cacheline_aligned, and that blows the array up to
4096 bytes on SMP P4 Xeons, 2048 bytes on SMP K7s, and 1024 bytes
on SMP P5/P6s. The patch reduces this to NR_CPUS*4==128 bytes.

I've noticed that xtime_lock and timerlist_lock ends up on the same
cacheline  all the time (atleaset on x86).  Not a good thing for
loads with high xxx_timer and do_gettimeofday counts I guess (networking etc).

Here's a trivial fix.

This is a complete rewrite of the LDM driver (support for Windows
Dynamic Disks).  It incorporates Al Viro's recent partition handling
tidy ups.

Details:
  LDM Driver rewritten.  More efficient.  Much smaller memory footprint.

  The old driver was little more than a stopgap.
  The new driver is a complete rewrite
  based on a much better understanding of the database
  based on much more reverse engineering
  more able to spot errors and inconsistancies
  it has a much smaller memory footprint
  no longer considered experimental
  accompanied by brief info: Documentation/ldm.txt

On a ppc64 machine running 2.5.28 we were hitting this BUG in
__free_pages_ok:

BUG_ON(page->pte.chain != NULL);

In pte_chain_lock we use test_and_set_bit which implies a memory
barrier. In pte_chain_unlock we use clear_bit which has no memory
barriers so we need to add one.

Here's a patch from Christoph Hellwig and myself to supply write->read
semaphore downgrade, and also from Brian Watson to supply trylock for rwsems.