For K8 system: 4G RAM with memory hole remapping enabled, or more than
4G RAM installed.

when try to use kexec second kernel, and the first doesn't include
gart_shutdown. the second kernel could have different aper position than
the first kernel. and second kernel could use that hole as RAM that is
still used by GART set by the first kernel. esp. when try to kexec
2.6.24 with sparse mem enable from previous kernel (from RHEL 5 or SLES
10). the new kernel will use aper by GART (set by first kernel) for
vmemmap. and after new kernel setting one new GART. the position will be
real RAM. the _mapcount set is lost.

Bad page state in process 'swapper'
page:ffffe2000e600020 flags:0x0000000000000000 mapping:0000000000000000 mapcount:1 count:0
Trying to fix it up, but a reboot is needed
Backtrace:
Pid: 0, comm: swapper Not tainted 2.6.24-rc7-smp-gcdf71a10-dirty #13

Call Trace:
 [<ffffffff8026401f>] bad_page+0x63/0x8d
 [<ffffffff80264169>] __free_pages_ok+0x7c/0x2a5
 [<ffffffff80ba75d1>] free_all_bootmem_core+0xd0/0x198
 [<ffffffff80ba3a42>] numa_free_all_bootmem+0x3b/0x76
 [<ffffffff80ba3461>] mem_init+0x3b/0x152
 [<ffffffff80b959d3>] start_kernel+0x236/0x2c2
 [<ffffffff80b9511a>] _sinittext+0x11a/0x121

and
 [ffffe2000e600000-ffffe2000e7fffff] PMD ->ffff81001c200000 on node 0
phys addr is : 0x1c200000

RHEL 5.1 kernel -53 said:
PCI-DMA: aperture base @ 1c000000 size 65536 KB

new kernel said:
Mapping aperture over 65536 KB of RAM @ 3c000000

So could try to disable that GART if possible.

According to Ingo

> hm, i'm wondering, instead of modifying the GART, why dont we simply
> _detect_ whatever GART settings we have inherited, and propagate that
> into our e820 maps? I.e. if there's inconsistency, then punch that out
> from the memory maps and just dont use that memory.
>
> that way it would not matter whether the GART settings came from a [old
> or crashing] Linux kernel that has not called gart_iommu_shutdown(), or
> whether it's a BIOS that has set up an aperture hole inconsistent with
> the memory map it passed. (or the memory map we _think_ i tried to pass
> us)
>
> it would also be more robust to only read and do a memory map quirk
> based on that, than actively trying to change the GART so early in the
> bootup. Later on we have to re-enable the GART _anyway_ and have to
> punch a hole for it.
>
> and as a bonus, we would have shored up our defenses against crappy
> BIOSes as well.

add e820 modification for gart inconsistent setting.

gart_fix_e820=off could be used to disable e820 fix.
Signed-off-by: NYinghai Lu <yinghai.lu@sun.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

setup_node_zones() calcuates some variables but only use them when
FLAT_NODE_MEM_MAP is set

so change the MACRO postion to avoid calculating.

also change it to static, and rename it to flat_setup_node_zones().
Signed-off-by: NYinghai Lu <yinghai.lu@sun.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

NOP change.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

These are useful in figuring out early-mapping problems.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

printk_address()'s second parameter is the reliability indication,
not the ebp. If we're printing regs->ip we're reliable by definition,
so pass a 1 here.

Signed-off-by: Arjan van de Ven
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

The 32 bit x86 tree has a very useful feature that prints the Code: line
for the code even before the trapping instrution (and the start of the
trapping instruction is then denoted with a <>). Unfortunately, the 64 bit
x86 tree does not yet have this feature, making diagnosing backtraces harder
than needed.

This patch adds this feature in the same was as the 32 bit tree has
(including the same kernel boot parameter), and including a bugfix
to make the code use probe_kernel_address() rarther than a buggy (deadlocking)
__get_user.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

During the work on the x86 32 and 64 bit backtrace code I found it useful
to have a simple test module to test a process and irq context backtrace.
Since the existing backtrace code was buggy, I figure it might be useful
to have such a test module in the kernel so that maybe we can even
detect such bugs earlier..

[ mingo@elte.hu: build fix ]
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

x86 32 bit already has this feature: This patch uses the stack frames with
frame pointer into an exact stack trace, by following the frame pointer.
This only affects kernels built with the CONFIG_FRAME_POINTER config option
enabled, and greatly reduces the amount of noise in oopses.

This code uses the traditional method of doing backtraces, but if it
finds a valid frame pointer chain, will use that to show which parts
of the backtrace are reliable and which parts are not

Due to the fragility and importance of the backtrace code, this needs to
be well reviewed and well tested before merging into mainlne.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

This patch turns the x86 64 bit HANDLE_STACK macro in the backtrace code
into a function, just like 32 bit has. This is needed pre work in order to
get exact backtraces for CONFIG_FRAME_POINTER to work.

The function and it's arguments are not the same as 32 bit; due to the
exception/interrupt stack way of x86-64 there are a few differences.

This patch should not have any behavior changes, only code movement.

Due to the fragility and importance of the backtrace code, this needs to be
well reviewed and well tested before merging into mainlne.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Right now, we take the stack pointer early during the backtrace path, but
only calculate bp several functions deep later, making it hard to reconcile
the stack and bp backtraces (as well as showing several internal backtrace
functions on the stack with bp based backtracing).

This patch moves the bp taking to the same place we take the stack pointer;
sadly this ripples through several layers of the back tracing stack,
but it's not all that bad in the end I hope.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

The 32 bit Frame Pointer backtracer code checks if the EBP is valid
to do a backtrace; however currently on a failure it just gives up
and prints nothing. That's not very nice; we can do better and still
print a decent backtrace.

This patch changes the backtracer to use the regular backtracing algorithm
at the same time as the EBP backtracer; the EBP backtracer is basically
used to figure out which part of the backtrace are reliable vs those
which are likely to be noise.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

For enhancing the 32 bit EBP based backtracer, I need the capability
for the backtracer to tell it's customer that an entry is either
reliable or unreliable, and the backtrace printing code then needs to
print the unreliable ones slightly different.

This patch adds the basic capability, the next patch will add a user
of this capability.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

The current x86 32 bit FRAME_POINTER chasing code has a nasty bug in
that the EBP tracer doesn't actually update the value of EBP it is
tracing, so that the code doesn't actually switch to the irq stack
properly.

The result is a truncated backtrace:

 WARNING: at timeroops.c:8 kerneloops_regression_test() (Not tainted)
 Pid: 0, comm: swapper Not tainted 2.6.24-0.77.rc4.git4.fc9 #1
  [<c040649a>] show_trace_log_lvl+0x1a/0x2f
  [<c0406d41>] show_trace+0x12/0x14
  [<c0407061>] dump_stack+0x6c/0x72
  [<e0258049>] kerneloops_regression_test+0x44/0x46 [timeroops]
  [<c04371ac>] run_timer_softirq+0x127/0x18f
  [<c0434685>] __do_softirq+0x78/0xff
  [<c0407759>] do_softirq+0x74/0xf7
  =======================

This patch fixes the code to update EBP properly, and to check the EIP
before printing (as the non-framepointer backtracer does) so that
the same test backtrace now looks like this:

 WARNING: at timeroops.c:8 kerneloops_regression_test()
 Pid: 0, comm: swapper Not tainted 2.6.24-rc7 #4
  [<c0405d17>] show_trace_log_lvl+0x1a/0x2f
  [<c0406681>] show_trace+0x12/0x14
  [<c0406ef2>] dump_stack+0x6a/0x70
  [<e01f6040>] kerneloops_regression_test+0x3b/0x3d [timeroops]
  [<c0426f07>] run_timer_softirq+0x11b/0x17c
  [<c04243ac>] __do_softirq+0x42/0x94
  [<c040704c>] do_softirq+0x50/0xb6
  [<c04242a9>] irq_exit+0x37/0x67
  [<c040714c>] do_IRQ+0x9a/0xaf
  [<c04057da>] common_interrupt+0x2e/0x34
  [<c05807fe>] cpuidle_idle_call+0x52/0x78
  [<c04034f3>] cpu_idle+0x46/0x60
  [<c05fbbd3>] rest_init+0x43/0x45
  [<c070aa3d>] start_kernel+0x279/0x27f
  =======================

This shows that the backtrace goes all the way down to user context now.
This bug was found during the port to 64 bit of the frame pointer backtracer.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Enable CONFIG_EMBEDDED to select CONFIG_EARLY_PRINTK on 64-bit as well.

saves ~2K:

   text    data     bss     dec     hex filename
   7290283 3672091 1907848 12870222         c4624e vmlinux.before
   7288373 3671795 1907848 12868016         c459b0 vmlinux.after
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

It's not too pretty, but I found this made the "PANIC: early exception"
messages become much more reliably useful: 1. print the vector number,
2. print the %cs value, 3. handle error-code-pushing vs non-pushing vectors.
Signed-off-by: NRoland McGrath <roland@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Fix section mismatches.  discover_ebda() can be __init.

WARNING: vmlinux.o(.text+0x738a): Section mismatch: reference to .init.data:ebda_addr (between 'discover_ebda' and 'get_model_name')
WARNING: vmlinux.o(.text+0x73c4): Section mismatch: reference to .init.data:ebda_size (between 'discover_ebda' and 'get_model_name')
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

The check for an unitialized clock event device triggers, when the local
apic timer is registered as a dummy clock event device for broadcasting.
Preset the multiplicator to avoid a false positive.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Check the APIC timer calibration result for sanity. When the frequency
is out of range, issue a warning and disable the local APIC timer.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The GDT_ENTRY() macro in pm.c would incorrectly cut the bottom 8 bits
off the base.  We didn't define any bases with the bottom 8 bits
nonzero, so it is a non-manifest bug, but it's still a bug.

Pointed out by John Smith <johnsmith9344@gmail.com>.
Cc: John Smith <johnsmith9344@gmail.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

If we use the bootloader-provided stack pointer, we might end up in a
situation where the bootloader (incorrectly) pointed the stack in the
middle of our heap.  Catch this by simply comparing the computed heap
end value to the stack pointer minus the defined stack size.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Push video mode setup as late as possible; messages issued through the
BIOS interface after video mode setup will either not be seen (for
framebuffer modes) or will screw up the cursor (for text modes.)

In particular, this makes the EDD probing message show up correctly.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Tell the user to specify edd=off in the case of EDD probing hangs.
Per LKML discussion.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Add prototype for cmdline_find_option_bool() missing from:

    x86 setup: early cmdline parser handle boolean options

Also, fix up a minor formatting error in that patch.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Unnecessary capitals are shouting; no need for it here.
Thus, change "OK" to "ok" and add a space.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

On early boot, probing the Bios for EDD happens without any message.

Enhanced Disk Drive Services (EDD) is a mechanism to match x86 BIOS device
names (int13 device 80h) to Linux device names (e.g. /dev/sda, /dev/hda)

There are buggy Bios out there having problems with EDD. This can be problems
with the Bios itself or with addon cards, too.

This patch is adds an informational message on early boot.

CONFIG_EDD is not set with defconfig, but with allmodconfig (i.e. CONFIG_EDD=m)
so the EDD probe may be active on early boot on many systems nowadays.

I can tell, that the probe is active on SuSE distro and with that I have seen
more than one system hanging endlessly with those "black screen with a blinking
cursor in the the upper left" on installation, making it difficult for the end-
user to find out, what`s the issue.
For sure I have seen this on FujitsuSiemens PCs with i810 and with i815 chipset.

This one also honours the "quiet" bootparam.

Also see:
http://marc.info/?l=linux-kernel&m=119781937207969&w=2
http://marc.info/?l=linux-kernel&m=119783934032326&w=2
http://marc.info/?l=linux-kernel&m=119783678529100&w=2Signed-off-by: NRoland Kletzing <devzero@web.de>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

This patch extends the early commandline parser to support boolean options.
The current version in mainline only supports parsing "option=arg" value pairs.

With this it should be easy making other messages like "Uncompressing kernel"
honour the "quiet" parameter, too.
Signed-off-by: NRoland Kletzing <devzero@web.de>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Fix the operand constraints for the segment accessor functions,
{rd,wr}{fs,gs}*.  In particular, the 8-bit functions used "r"
constraints instead of "q" constraints.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Display VESA graphics modes, with their mode IDs, in the vga=ask
menu.  Most VESA mode numbers are platform-dependent, so it helps to
have an easy way to display them.

Based in part on a patch by Petr Vandrovec <petr@vandrovec.name>.

Cc: Petr Vandrovec <petr@vandrovec.name>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

To set CR0.PE, use the X86_CR0_PE macro defined in
<asm/processor-flags.h> instead of hardcoding it as a constant (1).
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Intel VT doesn't like to engage when the protected-mode state isn't
fully initialized.  Make life easier for it by initializing LDTR (to
null) and TR (to a dummy hunk of low memory which will never actually
be touched.)
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Make the transition to protected mode more paranoid by having
back-to-back near jump (to synchronize the 386/486 prefetch queue) and
far jump (to set up the code segment.)

While we're at it, zero as many registers as practical (for future
expandability of the 32-bit entry interface) and enter 32-bit mode
with a valid stack.  Note that the 32-bit code cannot rely on this
stack, or we'll break all other existing users of the 32-bit
entrypoint, but it may make debugging hacks easier to write.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

The boot GDT entries are common between 32- and 64-bit mode, so move
them to common code instead of having two identical copies.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Signed-off-by: NHarvey Harrison <harvey.harrison@gmail.com>
Acked-by: NMasami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

get_segment_eip has similarities to convert_rip_to_linear(),
and is used in a similar context.  Move get_segment_eip to
step.c to allow easier consolidation.
Signed-off-by: NHarvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Move out tick_nohz_stop_sched_tick() call from the loop in cpu_idle
same as 32-bit version.
Signed-off-by: NHiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

introduce the "asmregparm" calling convention: for functions
implemented in assembly with a fixed regparm input parameters
calling convention.

mark the semaphore and rwsem slowpath functions with that.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

This implements ticket lock support for more than 255 CPUs on x86. The
code gets switched according to the configured NR_CPUS.
Signed-off-by: NNick Piggin <npiggin@suse.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Simple coding style fixes.

no code changed:

   text    data     bss     dec     hex filename
   3139     576     194    3909     f45 fixup.o.before
   3139     576     194    3909     f45 fixup.o.after

  md5:
   9a3467057478b2d99962bdd448282eeb  fixup.o.before.asm
   9a3467057478b2d99962bdd448282eeb  fixup.o.after.asm
Signed-off-by: NPaolo Ciarrocchi <paolo.ciarrocchi@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>