Impact: improve MTRR debugging messages

There's still inefficiencies suspected with the MTRR sanitizing
code, so make sure we get all the info we need from a dmesg.

- Remove unneeded mtrr_show

 (It will only printout one time by first cpu, so it is no big deal.)

- Also print out directly from get_mtrr, because it doesn't update mtrr_state.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
LKML-Reference: <49B9BA5A.40108@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

kerneloops.org is reporting a lot of these warnings that come due to
vmware not setting up any MTRRs for emulated CPUs:

| Reported 709 times (14696 total reports)
| BIOS bug (often in VMWare) where the MTRR's are set up incorrectly
| or not at all
|
| This warning was last seen in version 2.6.29-rc2-git1, and first
| seen in 2.6.24.
|
| More info:
|   http://www.kerneloops.org/searchweek.php?search=mtrr_trim_uncached_memory

Keep a one-liner KERN_INFO about it - so that we have so notice if empty
MTRRs are caused by native hardware/BIOS weirdness.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

while looking at:

  http://bugzilla.kernel.org/show_bug.cgi?id=11541

I realized that the mtrr.show param cannot work, because
the code is processed much too early.

This patch:
 - Declares mtrr.show as early_param
 - Stays consistent with the previous param (which I doubt
   that it ever worked), so mtrr.show=1 would still work
 - Declares mtrr_show as initdata
Signed-off-by: NThomas Renninger <trenn@suse.de>
Acked-by: NJan Beulich <jbeulich@novell.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

For KVM can reuse the type define, and need them to support shadow MTRR.
Signed-off-by: NSheng Yang <sheng@linux.intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Prepare for exporting them.
Signed-off-by: NSheng Yang <sheng@linux.intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Impact: cleanup

enable_mtrr_cleanup is static, and is never set to anything but 0 or 1.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

Ingo said mtrr_cleanup() is big and ugly.

so break it up into more functions and make it more readable.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

For the purpose of MTRR canonicalization, treat WRPROT as UNCACHEABLE.
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

The first 1M is don't care when it comes to the variables MTRRs.
Cover it as WB as a heuristic approximation; this is generally what we
want to minimize the number of registers.
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

Print out the correct type when the Write Protected (WP) type is seen.
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

J.A. Magallón reported:

 >> Also, on a 64 bit box with 4Gb, it gives this:
 >>
 >> cicely:~# cat /proc/mtrr
 >> reg00: base=0x00000000 (   0MB), size=4096MB: write-back, count=1
 >> reg01: base=0x100000000 (4096MB), size=1024MB: write-back, count=1
 >> reg02: base=0x140000000 (5120MB), size= 512MB: write-back, count=1
 >> reg03: base=0x160000000 (5632MB), size= 256MB: write-back, count=1
 >> reg04: base=0x80000000 (2048MB), size=2048MB: uncachable, count=1

boundary handling has a problem ... fix it.
Reported-by: NJ.A. Magallón <jamagallon@ono.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Patch below cleans up formatting, with space for big bases and sizes (64 Gb).
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Correct typo for 'enable_mtrr_cleanup' early boot param name.
Signed-off-by: NJ.A. Magallon <jamagallon@ono.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

one have gran < 1M

reg00: base=0xd8000000 (3456MB), size= 128MB: uncachable, count=1
reg01: base=0xe0000000 (3584MB), size= 512MB: uncachable, count=1
reg02: base=0x00000000 (   0MB), size=4096MB: write-back, count=1
reg03: base=0x100000000 (4096MB), size= 512MB: write-back, count=1
reg04: base=0x120000000 (4608MB), size= 128MB: write-back, count=1
reg05: base=0xd7f80000 (3455MB), size= 512KB: uncachable, count=1

will get

Found optimal setting for mtrr clean up
gran_size: 512K         chunk_size: 2M  num_reg: 7      lose RAM: 0G
range0: 0000000000000000 - 00000000d8000000
Setting variable MTRR 0, base: 0GB, range: 2GB, type WB
Setting variable MTRR 1, base: 2GB, range: 1GB, type WB
Setting variable MTRR 2, base: 3GB, range: 256MB, type WB
Setting variable MTRR 3, base: 3328MB, range: 128MB, type WB
hole: 00000000d7f00000 - 00000000d7f80000
Setting variable MTRR 4, base: 3455MB, range: 512KB, type UC
rangeX: 0000000100000000 - 0000000128000000
Setting variable MTRR 5, base: 4GB, range: 512MB, type WB
Setting variable MTRR 6, base: 4608MB, range: 128MB, type WB

so start from 64k instead of 1M
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

make the print out right with size < 1M
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

Delay exit to make sure we can actually get the optimal result in as
many cases as possible.
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

v2: should check with half of range0 size instead of chunk_size

So don't have silly big hole.

in hpa's case we could auto detect instead of adding mtrr_chunk_size in
command line.
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

add mtrr_cleanup_debug to print out more info about layout
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

fix hpa's t61 with 4g ram:

   change layout from
	(n - 1)*chunksize + chunk_size - NC
   to
	n*chunksize - NC
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

change back chunksize max to 2g
   otherwise will get strange layout in 2G ram system like
     0 - 4g WB, 2040M - 2048M UC, 2048M -  4G NC
   instead of
     0 - 2g WB, 2040M - 2048M UC
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

so could help catch attention about bug in bios about mtrr mask setting.

WARN_ONCE got into mainline already, lets use it.
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

fix this warning reported by Andrew Morton:

> arch/x86/kernel/cpu/mtrr/main.c: In function 'mtrr_bp_init':
> arch/x86/kernel/cpu/mtrr/main.c:1170: warning: 'extra_remove_base' may be used uninitialized in this function

the warning is bogus but the logic that prevents uninitialized use
is a bit convoluted so simplify it all.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

improve the debug printout:

- make it actually display something
- print it only once

would be nice to have a WARN_ONCE() facility, to feed such things to
kerneloops.org.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Joshua Hoblitt reported that only 3 GB of his 16 GB of RAM is
usable. Booting with mtrr_show showed us the BIOS-initialized
MTRR settings - which are all wrong.

So the root cause is that the BIOS has not set the mask correctly:

>               [    0.429971]  MSR00000200: 00000000d0000000
>               [    0.433305]  MSR00000201: 0000000ff0000800
> should be ==> [    0.433305]  MSR00000201: 0000003ff0000800
>
>               [    0.436638]  MSR00000202: 00000000e0000000
>               [    0.439971]  MSR00000203: 0000000fe0000800
> should be ==> [    0.439971]  MSR00000203: 0000003fe0000800
>
>               [    0.443304]  MSR00000204: 0000000000000006
>               [    0.446637]  MSR00000205: 0000000c00000800
> should be ==> [    0.446637]  MSR00000205: 0000003c00000800
>
>               [    0.449970]  MSR00000206: 0000000400000006
>               [    0.453303]  MSR00000207: 0000000fe0000800
> should be ==> [    0.453303]  MSR00000207: 0000003fe0000800
>
>               [    0.456636]  MSR00000208: 0000000420000006
>               [    0.459970]  MSR00000209: 0000000ff0000800
> should be ==> [    0.459970]  MSR00000209: 0000003ff0000800

So detect this borkage and add the prefix 111.
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Cc: <stable@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Use WARN() instead of a printk+WARN_ON() pair; this way the message
becomes part of the warning section for better reporting/collection.
This also allowed the folding of some if()'s into the WARN()
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Cc: akpm@linux-foundation.org
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NJaswinder Singh <jaswinder@infradead.org>

rename update_memory_range to e820_update_range
rename add_memory_region to e820_add_region

to make it more clear that they are about e820 map operations.
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

It's never used and the comments refer to nonatomic and retry
interchangably. So get rid of it.
Acked-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

disable the noisy print out.
also use the one the less spare mtrr reg.
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

there is a typo in the mask value, need to remove that extra 0,
to avoid 4bit clearing.
Signed-off-by: NYinghal Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

otherwise fixed MTRR for family 10h may not be changed.
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Loop through mtrr chunk_size and gran_size from 1M to 2G to find out
the optimal value so user does not need to add mtrr_chunk_size and
mtrr_gran_size to the kernel command line.

If optimal value is not found, print out all list to help select less
optimal value.

Add mtrr_spare_reg_nr= so user could set 2 instead of 1, if the card
need more entries.

v2: find the one with more spare entries
v3: fix hole_basek offset
v4: tight the compare between range and range_new
    loop stop with 4g
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Gabriel C <nix.or.die@googlemail.com>
Cc: Mika Fischer <mika.fischer@zoopnet.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

v9: address format change requests by Ingo
    more case handling in range_to_var_with_hole
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

v2: process hole then end_pfn
    fix update_memory_range with whole cover comparing
Signed-off-by: NYinghai Lu <yinghai.lu@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

converting MTRR layout from continous to discrete, some time could run out of
MTRRs. So add gran_sizek to prevent that by dumpping small RAM piece less than
gran_sizek.

previous trimming only can handle highest_pfn from mtrr to end_pfn from e820.
when have more than 4g RAM installed, there will be holes below 4g. so need to
check ram below 4g is coverred well.

need to be applied after
	[PATCH] x86: mtrr cleanup for converting continuous to discrete layout v7
Signed-off-by: NYinghai Lu <yinghai.lu@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

some BIOS like to use continus MTRR layout, and X driver can not add
WB entries for graphical cards when 4g or more RAM installed.

the patch will change MTRR to discrete.

mtrr_chunk_size= could be used to have smaller continuous block to hold holes.
default is 256m, could be set according to size of graphics card memory.

mtrr_gran_size= could be used to send smallest mtrr block to avoid run out of MTRRs

v2: fix -1 for UC checking
v3: default to disable, and need use enable_mtrr_cleanup to enable this feature
    skip the var state change warning.
    remove next_basek in range_to_mtrr()
v4: correct warning mask.
v5: CONFIG_MTRR_SANITIZER
v6: fix 1g, 2g, 512 aligment with extra hole
v7: gran_sizek to prevent running out of MTRRs.
v8: fix hole_basek caculation caused when removing next_basek
    gran_sizek using when basek is 0.

need to apply
	[PATCH] x86: fix trimming e820 with MTRR holes.
right after this one.
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

arch/x86/kernel/cpu/mtrr/generic.c:216:12: warning: symbol 'lo' shadows an earlier one
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Remove proc_root export.  Creation and removal works well if parent PDE is
supplied as NULL -- it worked always that way.

So, one useless export removed and consistency added, some drivers created
PDEs with &proc_root as parent but removed them as NULL and so on.
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

As written, this can never be true.

Spotted by the Sparse checker.
Signed-off-by: NHarvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>