This adds the basic driver model support for the IDE subsystem.

Basically, it registers the controllers and devices with the driver
model core, which puts them in the device tree and gets them a directory
in driverfs.  The driverfs layout looks like this (on my workstation):

	[mochel@cherise mochel]$ tree -d /sys/root/pci0/
	/sys/root/pci0/
	|-- 00:00.0
	|-- 00:01.0
	|   `-- 01:00.0
	|-- 00:02.0
	|   `-- 02:1f.0
	|       `-- 03:00.0
	|-- 00:1e.0
	|   `-- 04:04.0
	|-- 00:1f.0
	|-- 00:1f.1
	|   |-- ide0
	|   |   |-- 0.0
	|   |   `-- 0.1
	|   `-- ide1
	|       |-- 1.0
	|       `-- 1.1

The drive bus IDs (the directory names)  are created using this:

	sprintf(bus_id,"%u.%u",hwif->index,unit);

which should give each drive a unique name for the entire system, right?

I've also created a struct bus_type for IDE, which gives ide a directory
in the driverfs bus/ directory. The layout of that is:

	[mochel@cherise mochel]$ tree -d /sys/bus/ide/
	/sys/bus/ide/
	|-- devices
	|   |-- 0.0 -> ../../../root/pci0/00:1f.1/ide0/0.0
	|   |-- 0.1 -> ../../../root/pci0/00:1f.1/ide0/0.1
	|   |-- 1.0 -> ../../../root/pci0/00:1f.1/ide1/1.0
	|   `-- 1.1 -> ../../../root/pci0/00:1f.1/ide1/1.1
	`-- drivers

Those are symlinks under devices/ (which is why the drive names must be
unique..). When drivers are registered with the IDE core, they should also
be passed through the core, which will give them a directory in the
drivers/ directory just above.

In general, there is a bit of code that can be cleaned up, and some
explicit calls removed, because of the way the driver model core works.
Most of these are pretty simple, and barring any objections, I will
implement and send them to you.

starting from 2.5.35 IDE stopped working on my alphas because of
following problems:

- ide_hwif_configure() ignores BARs for IDE base/control registers
  and assumes legacy 0x1f0/0x170 ports, unless controller reports
  native PCI mode (ProgIf bits 0 and 2).

  This is incorrect, as there are quite a few IDE chips operating
  in "semi-legacy" mode, i.e. legacy interrupts, but functional
  BAR0-3, like cy82c693 and ali5229. I guess Andre could give a lot
  more examples. :-)

  This happens to work on i386 simply because BIOS usually assigns
  legacy values to BAR0-3, but we can't rely on it.

  Just checking respective resource->start for zero should work in
  all cases.

- ide_pci_check_iomem(): resource->flags == 0 means "unconfigured" as well.
  Thus we avoid false positives.

- Apparently cut'n'paste typo in cy82c693.c - wrong PCI IDs.

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

into samba.org:/scratch/anton/linux-2.5_ppc64

into samba.org:/scratch/anton/linux-2.5_ppc64

into samba.org:/scratch/anton/linux-2.5_ppc64_new

into samba.org:/scratch/anton/linux-2.5_ppc64_new

into samba.org:/scratch/anton/linux-2.5_ppc64_Makefilecleanup

into samba.org:/scratch/anton/linux-2.5_ppc64_Makefilecleanup

into samba.org:/scratch/anton/linux-2.5_ppc64_new

into samba.org:/scratch/anton/linux-2.5_ppc64_new

into samba.org:/scratch/anton/linux-2.5_ppc64

into samba.org:/scratch/anton/linux-2.5_ppc64_Makefilecleanup

into samba.org:/scratch/anton/linux-2.5_ppc64_Makefilecleanup

into samba.org:/scratch/anton/linux-2.5_ppc64_new

into samba.org:/scratch/anton/linux-2.5_ppc64_new

into samba.org:/scratch/anton/linux-2.5_ppc64

the attached patch (against BK-curr) fixes a bug in the new PID allocator,
which bug can cause incorrect hashing of the PID structure which causes
infinite loops in find_pid(). [and potentially other problems.]

into samba.org:/scratch/anton/linux-2.5_ppc64_new

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

Patch from Rohit Seth: allow hugetlb pages to be allocated from the
highmem zone.

From Marcus Alanen <maalanen@ra.abo.fi>

Don't retake the zone lock after spilling a batch of pages into the
buddy.

Instead, just clear local variable `zone' to indicate that no lock is
held.

This is actually a common case - whenever release_pages() is called
with exactly 16 pages (truncate, page reclaim..) Marcus' patch will
save a lock and an unlock.

Also, remove some lock-avoidance heuristics in
pagevec_deactivate_inactive(): the caller has already made these
checks, and the chance of the check here actually doing anything useful
is negligible.

- Spell Jeremy's name correctly.

- Fix compile warning in raw.c

- Do a waitqueue_active() test before waking klogd in printk.

  Not only is is negligibly faster, but the wake_up() in there causes
  deadlocks when you try to print debug info out from inside scheduler
  code.

  This patch gives a delightfully obscure way of avoiding the
  deadlock: kill off klogd.

- Fix a couple of compile warnings in the mtrr code.

From Christoph Hellwig, acked by Jens.

- remove some unneeded runtime initializers.

- remove the explicit call to hd_init() - it already goes through
module_init(), so we're currently running hd_init() twice.

From Christoph Hellwig, acked by Rohit.

- fix config.in description: we know we're on i386 and we also know
that a feature can only be enabled if the hw supports it, the code
alone is not enough

- the sysctl is VM-releated, so move it from /proc/sys/kernel tp
/proc/sys/vm

- adopt to standard sysctl names

From Christoph Hellwig.

There are no lock_kernel() calls in mm/

From Hubertus Franke.

The MAP_LOCKED flag to mmap() currently does nothing.  Hubertus' patch
fixes it so that the relevant mapping is locked into memory, if the
called has CAP_IPC_LOCK.

Somebody somewhere is stomping on PF_NOWARN, and page allocation
failure warnings are coming out of the wrong places.

So change the handling of current->flags to be:

int pf_flags = current->flags;

current->flags |= PF_NOWARN;
...
current->flags = pf_flags;

which is a generally more robust approach.

- writev currently returns -EFAULT if _any_ of the segments has an
invalid address.  We should only return -EFAULT if the first segment
has a bad address.

If some of the first segments have valid addresses we need to write
them and return a partial result.

- The current code only checks if the sum-of-lengths is negative.  If
individual segments have a negative length but the result is positive
we miss that.

So rework the code to detect this, and to be immune to odd wrapping
situations.

As a bonus, we save one pass across the iovec.

- ditto for readv.

The check for "does any segment have a negative length" has already
been performed in do_readv_writev(), but it's basically free here, and
we need to do it for generic_file_read/write anyway.

This all means that the iov_length() function is unsafe because of
wrap/overflow isues.  It should only be used after the
generic_file_read/write or do_readv_writev() checking has been
performed.  Its callers have been reviewed and they are OK.

The code now passes LTP testing and has been QA'd by Janet's team.

A patch from Hirokazu Takahashi to speed up the new sped-up writev
code.

Instead of running ->prepare_write/->commit_write for each individual
segment, we walk the segments between prepage and commit.  So
potentially much larger amounts of data are passed to commit_write(),
and prepare_write() is called much less often.

Added bonus: the segment walk happens inside the kmap_atomic(), so we
run kmap_atomic() once per page, not once per segment.

We've demonstrated a speedup of over 3x.  This is writing 1024-segment
iovecs where the individual segments have an average length of 24
bytes, which is a favourable case for this patch.

Silly bug which was halving swapout bandwidth: we've taken a copy of
page->mapping into a local convenience variable, but forgot to update
that local after adding the page to swapcache.