* git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86: (24 commits)
x86: no robust/pi futex for real i386 CPUs
x86: fix boot failure on 486 due to TSC breakage
x86: fix build on non-C locales.
x86: make c_idle.work have a static address.
x86: don't save unreliable stack trace entries
x86: don't make swapper_pg_pmd global
x86: don't print a warning when MTRR are blank and running in KVM
x86: fix execve with -fstack-protect
x86: fix vsyscall wreckage
x86: rename KERNEL_TEXT_SIZE => KERNEL_IMAGE_SIZE
x86: fix spontaneous reboot with allyesconfig bzImage
x86: remove double-checking empty zero pages debug
x86: notsc is ignored on common configurations
x86/mtrr: fix kernel-doc missing notation
x86: handle BIOSes which terminate e820 with CF=1 and no SMAP
x86: add comments for NOPs
x86: don't use P6_NOPs if compiling with CONFIG_X86_GENERIC
x86: require family >= 6 if we are using P6 NOPs
x86: do not promote TM3x00/TM5x00 to i686-class
x86: hpet fix docbook comment
...
* git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched:
latencytop: change /proc task_struct access method
latencytop: fix memory leak on latency proc file
latencytop: fix kernel panic while reading latency proc file
sched: add declaration of sched_tail to sched.h
sched: fix signedness warnings in sched.c
sched: clean up __pick_last_entity() a bit
sched: remove duplicate code from sched_fair.c
sched: make early bootup sched_clock() use safer
printk recursion detection prepends message to printk_buf and offsets
printk_buf when actual message is printed but it forgets to trim buffer
length accordingly. This can result in overrun in extreme cases. Fix it.
[ mingo@elte.hu:
bug was introduced by me via:
commit 32a7600668
Author: Ingo Molnar <mingo@elte.hu>
Date: Fri Jan 25 21:07:58 2008 +0100
printk: make printk more robust by not allowing recursion
]
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Real i386 CPUs do not have cmpxchg instructions. Catch it before
crashing on an invalid opcode.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> Diffing dmesg between git7 and git8 doesn't sched any light since
> git8 also removed the printouts of the x86 caps as they were being
> initialised and updated. I'm currently adding those printouts back
> in the hope of seeing where and when the caps get broken.
That turned out to be very illuminating:
--- dmesg-2.6.24-git7 2008-02-24 18:01:25.295851000 +0100
+++ dmesg-2.6.24-git8 2008-02-24 18:01:25.530358000 +0100
...
CPU: After generic identify, caps: 00000003 00000000 00000000 00000000 00000000 00000000 00000000 00000000
CPU: After all inits, caps: 00000003 00000000 00000000 00000000 00000000 00000000 00000000 00000000
+CPU: After applying cleared_cpu_caps, caps: 00000013 00000000 00000000 00000000 00000000 00000000 00000000 00000000
Notice how the TSC cap bit goes from Off to On.
(The first two lines are printout loops from -git7 forward-ported
to -git8, the third line is the same printout loop added just after
the xor-with-cleared_cpu_caps[] loop.)
Here's how the breakage occurs:
1. arch/x86/kernel/tsc_32.c:tsc_init() sees !cpu_has_tsc,
so bails and calls setup_clear_cpu_cap(X86_FEATURE_TSC).
2. include/asm-x86/cpufeature.h:setup_clear_cpu_cap(bit) clears
the bit in boot_cpu_data and sets it in cleared_cpu_caps
3. arch/x86/kernel/cpu/common.c:identify_cpu() XORs all caps
in with cleared_cpu_caps
HOWEVER, at this point c->x86_capability correctly has TSC
Off, cleared_cpu_caps has TSC On, so the XOR incorrectly
sets TSC to On in c->x86_capability, with disastrous results.
The real bug is that clearing bits with XOR only works if the
bits are known to be 1 prior to the XOR, and that's not true here.
A simple fix is to convert the XOR to AND-NOT instead. The following
patch does that, and allows my 486 to boot 2.6.25-rc kernels again.
[ mingo@elte.hu: fixed a similar bug in setup_64.c as well. ]
The breakage was introduced via commit 7d851c8d3d.
Signed-off-by: Mikael Pettersson <mikpe@it.uu.se>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
For some locales regex range [a-zA-Z] does not work as it is supposed to.
so we have to use [:alnum:] and [:xdigit:] to make it work as intended.
[1] http://en.wikipedia.org/wiki/Estonian_alphabet
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Currently, c_idle is declared in the stack, and thus, have no static address.
Peter Zijlstra points out this simple solution, in which c_idle.work
is initializated separatedly. Note that the INIT_WORK macro has a static
declaration of a key inside.
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Acked-by: Peter Zijlstra <pzijlstr@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Currently, there is no way for print_stack_trace() to determine whether
a given stack trace entry was deemed reliable or not, simply because
save_stack_trace() does not record this information. (Perhaps needless
to say, this makes the saved stack traces A LOT harder to read, and
probably with no other benefits, since debugging features that use
save_stack_trace() most likely also require frame pointers, etc.)
This patch reverts to the old behaviour of only recording the reliable trace
entries for saved stack traces.
Signed-off-by: Vegard Nossum <vegardno@ifi.uio.no>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
There doesn't seem to be any reason for swapper_pg_pmd being global.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Inside a KVM virtual machine the MTRRs are usually blank. This confuses Linux
and causes a warning message at boot. This patch removes that warning message
when running Linux as a KVM guest.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
pointed out by pageexec@freemail.hu:
> what happens here is that gcc treats the argument area as owned by the
> callee, not the caller and is allowed to do certain tricks. for ssp it
> will make a copy of the struct passed by value into the local variable
> area and pass *its* address down, and it won't copy it back into the
> original instance stored in the argument area.
>
> so once sys_execve returns, the pt_regs passed by value hasn't at all
> changed and its default content will cause a nice double fault (FWIW,
> this part took me the longest to debug, being down with cold didn't
> help it either ;).
To fix this we pass in pt_regs by pointer.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
based on a report from Arne Georg Gleditsch about user-space apps
misbehaving after toggling /proc/sys/kernel/vsyscall64, a review
of the code revealed that the "NOP patching" done there is
fundamentally unsafe for a number of reasons:
1) the patching code runs without synchronizing other CPUs
2) it inserts NOPs even if there is no clock source which provides vread
3) when the clock source changes to one without vread we run in
exactly the same problem as in #2
4) if nobody toggles the proc entry from 1 to 0 and to 1 again, then
the syscall is not patched out
as a result it is possible to break user-space via this patching.
The only safe thing for now is to remove the patching.
This code was broken since v2.6.21.
Reported-by: Arne Georg Gleditsch <arne.gleditsch@dolphinics.no>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The KERNEL_TEXT_SIZE constant was mis-named, as we not only map the kernel
text but data, bss and init sections as well.
That name led me on the wrong path with the KERNEL_TEXT_SIZE regression,
because i knew how big of _text_ my images have and i knew about the 40 MB
"text" limit so i wrongly thought to be on the safe side of the 40 MB limit
with my 29 MB of text, while the total image size was slightly above 40 MB.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
recently the 64-bit allyesconfig bzImage kernel started spontaneously
rebooting during early bootup.
after a few fun hours spent with early init debugging, it turns out
that we've got this rather annoying limit on the size of the kernel
image:
#define KERNEL_TEXT_SIZE (40*1024*1024)
which limit my vmlinux just happened to pass:
text data bss dec hex filename
29703744 4222751 8646224 42572719 2899baf vmlinux
40 MB is 42572719 bytes, so my vmlinux was just 1.5% above this limit :-/
So it happily crashed right in head_64.S, which - as we all know - is
the most debuggable code in the whole architecture ;-)
So increase the limit to allow an up to 128MB kernel image to be mapped.
(should anyone be that crazy or lazy)
We have a full 4K of pagetable (level2_kernel_pgt) allocated for these
mappings already, so there's no RAM overhead and the limit was rather
pointless and arbitrary.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
notsc is ignored in 32-bit kernels if CONFIG_X86_TSC is on.. which is
bad, fix it.
Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Fix mtrr kernel-doc warning:
Warning(linux-2.6.24-git12//arch/x86/kernel/cpu/mtrr/main.c:677): No description found for parameter 'end_pfn'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The proper way to terminate the e820 chain is with %ebx == 0 on the
last legitimate memory block. However, several BIOSes don't do that
and instead return error (CF = 1) when trying to read off the end of
the list. For this error return, %eax doesn't necessarily return the
SMAP signature -- correctly so, since %ah should contain an error code
in this case.
To deal with some particularly broken BIOSes, we clear the entire e820
chain if the SMAP signature is missing in the middle, indicating a
plain insane e820 implementation. However, we need to make the test
for CF = 1 before the SMAP check.
This fixes at least one HP laptop (nc6400) for which none of the
memory-probing methods (e820, e801, 88) functioned fully according to
spec.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Add comments describing the various NOP sequences.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
P6_NOPs are definitely not supported on some VIA CPUs, and possibly
(unverified) on AMD K7s. It is also the only thing that prevents a
686 kernel from running on Transmeta TM3x00/5x00 (Crusoe) series.
The performance benefit over generic NOPs is very small, so when
building for generic consumption, avoid using them.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The P6 family of NOPs are only available on family >= 6 or above, so
enforce that in the boot code.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
We have been promoting Transmeta TM3x00/TM5x00 chips to i686-class
based on the notion that they contain all the user-space visible
features of an i686-class chip. However, this is not actually true:
they lack the EA-taking long NOPs (0F 1F /0). Since this is a
userspace-visible incompatibility, downgrade these CPUs to the
manufacturer-defined i586 level.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Use PF_MEMALLOC to prevent recursive calls in the DBEUG_PAGEALLOC
case. This makes the code simpler and more robust against allocation
failures.
This fixes the following fallback to non-mmconfig:
http://lkml.org/lkml/2008/2/20/551http://bugzilla.kernel.org/show_bug.cgi?id=10083
Also, for DEBUG_PAGEALLOC=n reduce the pool size to one page.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Hi all,
Beginning from commits close to v2.6.25-rc2, running lguest always oopses
the host kernel. Oops is at [1].
Bisection led to the following commit:
commit 37cc8d7f96
x86/early_ioremap: don't assume we're using swapper_pg_dir
At the early stages of boot, before the kernel pagetable has been
fully initialized, a Xen kernel will still be running off the
Xen-provided pagetables rather than swapper_pg_dir[]. Therefore,
readback cr3 to determine the base of the pagetable rather than
assuming swapper_pg_dir[].
static inline pmd_t * __init early_ioremap_pmd(unsigned long addr)
{
- pgd_t *pgd = &swapper_pg_dir[pgd_index(addr)];
+ /* Don't assume we're using swapper_pg_dir at this point */
+ pgd_t *base = __va(read_cr3());
+ pgd_t *pgd = &base[pgd_index(addr)];
pud_t *pud = pud_offset(pgd, addr);
pmd_t *pmd = pmd_offset(pud, addr);
Trying to analyze the problem, it seems on the guest side of lguest,
%cr3 has a different value from &swapper_pg-dir (which
is AFAIK fine on a pravirt guest):
Putting some debugging messages in early_ioremap_pmd:
/* Appears 3 times */
[ 0.000000] ***************************
[ 0.000000] __va(%cr3) = c0000000, &swapper_pg_dir = c02cc000
[ 0.000000] ***************************
After 8 hours of debugging and staring on lguest code, I noticed something
strange in paravirt_ops->set_pmd hypercall invocation:
static void lguest_set_pmd(pmd_t *pmdp, pmd_t pmdval)
{
*pmdp = pmdval;
lazy_hcall(LHCALL_SET_PMD, __pa(pmdp)&PAGE_MASK,
(__pa(pmdp)&(PAGE_SIZE-1))/4, 0);
}
The first hcall parameter is global pgdir which looks fine. The second
parameter is the pmd index in the pgdir which is suspectful.
AFAIK, calculating the index of pmd does not need a divisoin over four.
Removing the division made lguest work fine again . Patch is at [2].
I am not sure why the division over four existed in the first place. It
seems bogus, maybe the Xen patch just made the problem appear ?
[2]: The patch:
[PATCH] lguest: fix pgdir pmd index cacluation
Remove an error in index calculation which leads to removing
a not existing shadow page table (leading to a Null dereference).
Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Added a declaration to asm-x86/lguest.h and moved the extern arrays there
as well. As an alternative to including asm/lguest.h directly, an
include could be put in linux/lguest.h
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Cc: "rusty@rustcorp.com.au" <rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Change getting task_struct by get_proc_task() at read or write time,
and returns -ESRCH if get_proc_task() returns NULL.
This is same behavior as other /proc files.
Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
At lstats_open(), calling get_proc_task() gets task struct, but it never put.
put_task_struct() should be called when releasing.
Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Reading /proc/<pid>/latency or /proc/<pid>/task/<tid>/latency could cause
NULL pointer dereference.
In lstats_open(), get_proc_task() can return NULL, in which case the kernel
will oops at lstats_show_proc() because m->private is NULL.
When get_proc_task() returns NULL, the kernel should return -ENOENT.
This can be reproduced by the following script.
while :
do
date
bash -c 'ls > ls.$$' &
pid=$!
cat /proc/$pid/latency &
cat /proc/$pid/latency &
cat /proc/$pid/latency &
cat /proc/$pid/latency
done
Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Avoids sparse warnings:
kernel/sched.c:2170:17: warning: symbol 'schedule_tail' was not declared. Should it be static?
Avoids the need for an external declaration in arch/um/process.c
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Unsigned long values are always assigned to switch_count,
make it unsigned long.
kernel/sched.c:3897:15: warning: incorrect type in assignment (different signedness)
kernel/sched.c:3897:15: expected long *switch_count
kernel/sched.c:3897:15: got unsigned long *<noident>
kernel/sched.c:3921:16: warning: incorrect type in assignment (different signedness)
kernel/sched.c:3921:16: expected long *switch_count
kernel/sched.c:3921:16: got unsigned long *<noident>
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
pick_task_entity() duplicates existing code. This functionality can be
easily obtained using rb_last(). Avoid code duplication by using rb_last().
Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
do not call sched_clock() too early. Not only might rq->idle
not be set up - but pure per-cpu data might not be accessible
either.
this solves an ia64 early bootup hang with CONFIG_PRINTK_TIME=y.
Tested-by: Tony Luck <tony.luck@gmail.com>
Acked-by: Tony Luck <tony.luck@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Add the Intel ICH10 SMBus Controller DeviceID's and updates
Tolapai support.
Signed-off-by: Jason Gaston <jason.d.gaston@intel.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Don't require platform code to be #ifdeffed according to whether
I2C is enabled or not ... if it's not enabled, let GCC compile out
all I2C device declarations. (Issue noted on an NSLU2 build that
didn't configure I2C.)
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
When probing i2c-pca-isa writes to legacy ioports, which crashes the kernel
if there is no device at that port.
This patch adds a check_legacy_ioport call, so probe fails gracefully
and thus prevents the oops.
Signed-off-by: Christian Krafft <krafft@de.ibm.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Commit 8b798c4d16 broke
alchemy build, fix it. Pointed out by Adrian Bunk.
Signed-off-by: Manuel Lauss <mano@roarinelk.homelinux.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
The C99 specification states in section 6.11.5:
The placement of a storage-class specifier other than at the
beginning of the declaration specifiers in a declaration is an
obsolescent feature.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
While working on the PCA9564-platform driver, I sometimes had a glimpse at the
pxa-driver. I found some suspicious places, and this patch contains my
suggestions. Note: They are not tested, due to no hardware.
[JD: Some more fixes.]
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Tested-by: Mike Rapoport <mike@compulab.co.il>
Tested-by: Eric Miao <ymiao3@marvell.com>
Each call to i2c_get_adapter() must be followed by a call to
i2c_put_adapter() to release the grabbed reference. Otherwise the
reference count grows forever and the adapter can never be
unregistered.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Vladimir Ananiev <vovan888@gmail.com>
Acked-by: Tony Lindgren <tony@atomide.com>
* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev:
libata-core: fix kernel-doc warning
sata_fsl: fix build with ATA_VERBOSE_DEBUG
[libata] ahci: AMD SB700/SB800 SATA support 64bit DMA
libata-pmp: clear hob for pmp register accesses
libata: automatically use DMADIR if drive/bridge requires it
power_state: get rid of write-only variable in SATA
pata_atiixp: Use 255 sector limit
Fix libata-core kernel-doc warning:
Warning(linux-2.6.25-rc2-git6//drivers/ata/libata-core.c:168): No description found for parameter 'ap'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
This patch fixes build and few warnings when ATA_VERBOSE_DEBUG
is defined:
CC drivers/ata/sata_fsl.o
drivers/ata/sata_fsl.c: In function ‘sata_fsl_fill_sg’:
drivers/ata/sata_fsl.c:338: warning: format ‘%x’ expects type ‘unsigned int’, but argument 3 has type ‘void *’
drivers/ata/sata_fsl.c:338: warning: format ‘%x’ expects type ‘unsigned int’, but argument 4 has type ‘struct prde *’
drivers/ata/sata_fsl.c: In function ‘sata_fsl_qc_issue’:
drivers/ata/sata_fsl.c:459: error: ‘csr_base’ undeclared (first use in this function)
drivers/ata/sata_fsl.c:459: error: (Each undeclared identifier is reported only once
drivers/ata/sata_fsl.c:459: error: for each function it appears in.)
drivers/ata/sata_fsl.c: In function ‘sata_fsl_freeze’:
drivers/ata/sata_fsl.c:525: error: ‘csr_base’ undeclared (first use in this function)
make[2]: *** [drivers/ata/sata_fsl.o] Error 1
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
SB700 SATA controller can support 64 bit DMA, the previous commit
badc234157 was added with
careless reference to SB600, which should be modified by this patch.
Signed-off-by: Shane Huang <shane.huang@amd.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
>> Mark Lord wrote:
>>> Tejun, I've added PMP to sata_mv, and am now trying to get it
>>> to work with a Marvell PM attached.
>>>
>>> And the behaviour I see is very bizarre.
>>>
>>> After hard+soft resets, the PM signature is found,
>>> and libata interrogates the PM registers.
>>>
>>> It successfully reads register 0, and then register 1.
>>> But all subsequent registers read out (incorrectly) as zeros.
...
This behavior has been confirmed by Marvell with a SATA analyzer.
The Marvell port-multiplier apparently likes to see clean HOB
information when accessing PMP registers.
Since sata_mv uses PIO shadow register access, this doesn't happen
automatically, as it might in a more purely FIS-based driver (eg. ahci).
One way to fix this is to flag these commands with ATA_TFLAG_LBA48,
forcing libata to write out the HOB fields with known (zero) values.
Signed-off-by: Saeed Bishara <saeed@marvell.com>
Acked-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Back in 2.6.17-rc2, a libata module parameter was added for atapi_dmadir.
That's nice, but most SATA devices which need it will tell us about it
in their IDENTIFY PACKET response, as bit-15 of word-62 of the
returned data (as per ATA7, ATA8 specifications).
So for those which specify it, we should automatically use the DMADIR bit.
Otherwise, disc writing will fail by default on many SATA-ATAPI drives.
This patch adds ATA_DFLAG_DMADIR and make ata_dev_configure() set it
if atapi_dmadir is set or identify data indicates DMADIR is necessary.
atapi_xlat() is converted to check ATA_DFLAG_DMADIR before setting
DMADIR.
Original patch is from Mark Lord.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Mark Lord <mlord@pobox.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
