This patch modifies the x86_64 kernel so that it can be loaded and run
at any 2M aligned address, below 512G.  The technique used is to
compile the decompressor with -fPIC and modify it so the decompressor
is fully relocatable.  For the main kernel the page tables are
modified so the kernel remains at the same virtual address.  In
addition a variable phys_base is kept that holds the physical address
the kernel is loaded at.  __pa_symbol is modified to add that when
we take the address of a kernel symbol.

When loaded with a normal bootloader the decompressor will decompress
the kernel to 2M and it will run there.  This both ensures the
relocation code is always working, and makes it easier to use 2M
pages for the kernel and the cpu.

AK: changed to not make RELOCATABLE default in Kconfig
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

Currently __pa_symbol is for use with symbols in the kernel address
map and __pa is for use with pointers into the physical memory map.
But the code is implemented so you can usually interchange the two.

__pa which is much more common can be implemented much more cheaply
if it is it doesn't have to worry about any other kernel address
spaces.  This is especially true with a relocatable kernel as
__pa_symbol needs to peform an extra variable read to resolve
the address.

There is a third macro that is added for the vsyscall data
__pa_vsymbol for finding the physical addesses of vsyscall pages.

Most of this patch is simply sorting through the references to
__pa or __pa_symbol and using the proper one.  A little of
it is continuing to use a physical address when we have it
instead of recalculating it several times.

swapper_pgd is now NULL.  leave_mm now uses init_mm.pgd
and init_mm.pgd is initialized at boot (instead of compile time)
to the physmem virtual mapping of init_level4_pgd.  The
physical address changed.

Except for the for EMPTY_ZERO page all of the remaining references
to __pa_symbol appear to be during kernel initialization.  So this
should reduce the cost of __pa in the common case, even on a relocated
kernel.

As this is technically a semantic change we need to be on the lookout
for anything I missed.  But it works for me (tm).
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

o virt_to_page() call should be used on kernel linear addresses and not
  on kernel text and data addresses. Swsusp code uses it on kernel data
  (statically allocated swsusp_header).

o Allocate swsusp_header dynamically so that virt_to_page() can be used
  safely.

o I am changing this because in next few patches, __pa() on x86_64 will
  no longer support kernel text and data addresses and hibernation breaks.
Signed-off-by: NVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

o __pa() should be used only on kernel linearly mapped virtual addresses
  and not on kernel text and data addresses.

o Hibernation code needs to determine the physical address associated
  with kernel symbol to mark a section boundary which contains pages which
  don't have to be saved and restored during hibernate/resume operation.

o Move this piece of code in arch dependent section. So that architectures
  which don't have kernel text/data mapped into kernel linearly mapped
  region can come up with their own ways of determining physical addresses
  associated with a kernel text.
Signed-off-by: NVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

With the rewrite of the SMP trampoline and the early page
allocator there is nothing that needs identity mapped pages,
once we start executing C code.

So add zap_identity_mappings into head64.c and remove
zap_low_mappings() from much later in the code.  The functions
 are subtly different thus the name change.

This also kills boot_level4_pgt which was from an earlier
attempt to move the identity mappings as early as possible,
and is now no longer needed.  Essentially I have replaced
boot_level4_pgt with trampoline_level4_pgt in trampoline.S
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

o Moved wakeup_level4_pgt into the wakeup routine so we can
  run the kernel above 4G.

o Now we first go to 64bit mode and continue to run from trampoline and
  then then start accessing kernel symbols and restore processor context.
  This enables us to resume even in relocatable kernel context when
  kernel might not be loaded at physical addr it has been compiled for.

o Removed the need for modifying any existing kernel page table.

o Increased the size of the wakeup routine to 8K. This is required as
  wake page tables are on trampoline itself and they got to be at 4K
  boundary, hence one page is not sufficient.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

o Various cleanups. One of the main purpose of cleanups is that make
  wakeup.S as close as possible to trampoline.S.

o Following are the changes
	- Indentations for comments.
	- Changed the gdt table to compact form and to resemble the
	  one in trampoline.S
	- Take the jump to 32bit from real mode using ljmpl. Makes code
	  more readable.
	- After enabling long mode, directly take a long jump for 64bit
	  mode. No need to take an extra jump to "reach_comaptibility_mode"
	- Stack is not used after real mode. So don't load stack in
 	  32 bit mode.
	- No need to enable PGE here.
	- No need to do extra EFER read, anyway we trash the read contents.
	- No need to enable system call (EFER_SCE). Anyway it will be
	  enabled when original EFER is restored.
	- No need to set MP, ET, NE, WP, AM bits in cr0. Very soon we will
  	  reload the original cr0 while restroing the processor state.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

o Use appropriate names for 64bit regsiters.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

o Get rid of dead code in wakeup.S

o We never restore from saved_gdt, saved_idt, saved_ltd, saved_tss, saved_cr3,
  saved_cr4, saved_cr0, real_save_gdt, saved_efer, saved_efer2. Get rid
  of of associated code.

o Get rid of bogus_magic, bogus_31_magic and bogus_magic2. No longer being
  used.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

This modifies the SMP trampoline and all of the associated code so
it can jump to a 64bit kernel loaded at an arbitrary address.

The dependencies on having an idenetity mapped page in the kernel
page tables for SMP bootup have all been removed.

In addition the trampoline has been modified to verify
that long mode is supported.  Asking if long mode is implemented is
down right silly but we have traditionally had some of these checks,
and they can't hurt anything.  So when the totally ludicrous happens
we just might handle it correctly.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

EFER varies like %cr4 depending on the cpu capabilities, and which cpu
capabilities we want to make use of.  So save/restore it make certain
we have the same EFER value when we are done.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

Move __KERNEL32_CS up into the unused gdt entry.  __KERNEL32_CS is
used when entering the kernel so putting it first is useful when
trying to keep boot gdt sizes to a minimum.

Set the accessed bit on all gdt entries.  We don't care
so there is no need for the cpu to burn the extra cycles,
and it potentially allows the pages to be immutable.  Plus
it is confusing when debugging and your gdt entries mysteriously
change.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

Use virtual addresses instead of physical addresses
in copy bootdata.  In addition fix the implementation
of the old bootloader convention.  Everything is
at real_mode_data always.  It is just that sometimes
real_mode_data was relocated by setup.S to not sit at
0x90000.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

- Merge physmem_pgt and ident_pgt, removing physmem_pgt.  The merge
  is broken as soon as mm/init.c:init_memory_mapping is run.
- As physmem_pgt is gone don't export it in pgtable.h.
- Use defines from pgtable.h for page permissions.
- Fix the physical memory identity mapping so it is at the correct
  address.
- Remove the physical memory mapping from wakeup_level4_pgt it
  is at the wrong address so we can't possibly be usinging it.
- Simply NEXT_PAGE the work to calculate the phys_ alias
  of the labels was very cool.  Unfortuantely it was a brittle
  special purpose hack that makes maitenance more difficult.
  Instead just use label - __START_KERNEL_map like we do
  everywhere else in assembly.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

Early in the boot process we need the ability to set
up temporary mappings, before our normal mechanisms are
initialized.  Currently this is used to map pages that
are part of the page tables we are building and pages
during the dmi scan.

The core problem is that we are using the user portion of
the page tables to implement this.  Which means that while
this mechanism is active we cannot catch NULL pointer dereferences
and we deviate from the normal ways of handling things.

In this patch I modify early_ioremap to map pages into
the kernel portion of address space, roughly where
we will later put modules, and I make the discovery of
which addresses we can use dynamic which removes all
kinds of static limits and remove the dependencies
on implementation details between different parts of the code.

Now alloc_low_page() and unmap_low_page() use
early_iomap() and early_iounmap() to allocate/map and
unmap a page.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

This patch makes pgtable.h and page.h safe to include
in assembly files like head.S.  Allowing us to use
symbolic constants instead of hard coded numbers when
refering to the page tables.

This patch copies asm-sparc64/const.h to asm-x86_64 to
get a definition of _AC() a very convinient macro that
allows us to force the type when we are compiling the
code in C and to drop all of the type information when
we are using the constant in assembly.  Previously this
was done with multiple definition of the same constant.
const.h was modified slightly so that it works when given
CONFIG options as arguments.

This patch adds #ifndef __ASSEMBLY__ ... #endif
and _AC(1,UL) where appropriate so the assembler won't
choke on the header files.  Otherwise nothing
should have changed.

AK: added const.h to exported headers to fix headers_check
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

The dma_ops structure can be const since it never changes
after boot.
Signed-off-by: NStephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: NAndi Kleen <ak@suse.de>

smp_call_function and smp_call_function_single are almost complete
duplicates of the same logic.  This patch combines them by
implementing them in terms of the more general
smp_call_function_mask().
Signed-off-by: NJeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Cc: Stephane Eranian <eranian@hpl.hp.com>
Cc: Andrew Morton <akpm@osdl.org>
Cc: Andi Kleen <ak@suse.de>
Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Cc: Ingo Molnar <mingo@elte.hu>

This patch fixes the reporting of cpu_mhz in /proc/cpuinfo on CPUs with
a constant TSC rate and a kernel with disabled cpufreq.
Signed-off-by: NMark Langsdorf <mark.langsdorf@amd.com>
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

 arch/x86_64/kernel/apic.c     |    2 -
 arch/x86_64/kernel/time.c     |   58 +++++++++++++++++++++++++++++++++++++++---
 arch/x86_64/kernel/tsc.c      |   12 +++++---
 arch/x86_64/kernel/tsc_sync.c |    2 -
 include/asm-x86_64/proto.h    |    1
 5 files changed, 65 insertions(+), 10 deletions(-)

On Tue, Mar 13, 2007 at 05:33:09AM -0700, Randy.Dunlap wrote:
> On Tue, 13 Mar 2007, Glauber de Oliveira Costa wrote:
>
> > Tiny cleanup:
> >
> > In x86_64, the same functions for reading cr3 and writing cr{3,4} are
> > defined in tlbflush.h and system.h, whith just a name change.
> > The only difference is the clobbering of memory, which seems a safe, and
> > even needed change for the write_cr4. This patch removes the duplicate.
> > write_cr3() is moved to system.h for consistency.
>
> missing patch.....
>
thanks. Attached now

--
Glauber de Oliveira Costa
Red Hat Inc.
"Free as in Freedom"
Signed-off-by: NAndi Kleen <ak@suse.de>

The set_seg_base function isn't used anywhere (2.6.21-rc3-git1)
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NAndi Kleen <ak@suse.de>

Hi!

I sent this simple patch to lkml about two weeks ago and also cc'ed
to Linus, but seems that the patch got ignored. I decided to write to
you, because you have modified the relevant file most recently.

Below is a copy of the mail that is also available at
<http://lkml.org/lkml/2007/2/28/230>.
Signed-off-by: NAndi Kleen <ak@suse.de>

The reboot_fixups stuff seems to be a bit of a mess, specifically the
header is in linux/ when its a purely i386-specific piece of code.  I'm
not sure why it has its config option; its only currently needed for
"geode-gx1/cs5530a", so perhaps whatever config option controls that
hardware should enable this?
Signed-off-by: NJeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

Explicity specify that the caller should pin the user memory
otherwise the function will sleep
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@gmail.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

The kernel only supports gcc 3.2+ now so it doesn't make sense
anymore to explicitely check for options this compiler version
already has.

This actually fixes a bug. The -mprefered-stack-boundary check
never worked because gcc rightly complains

  CC      arch/i386/kernel/asm-offsets.s
cc1: -mpreferred-stack-boundary=2 is not between 4 and 12

We just never saw the error because of cc-options.
I changed it to 4 to actually work.

Tested by compiling i386 and x86-64 defconfig with gcc 3.2.

Should speed up the build time a tiny bit and improve
stack usage on i386 slightly.
Signed-off-by: NAndi Kleen <ak@suse.de>

Signed-off-by: NAndi Kleen <ak@suse.de>

Pointed out by Adrian Bunk
Signed-off-by: NAndi Kleen <ak@suse.de>

Change sysenter_setup to __cpuinit.
Change __INIT & __INITDATA to be cpu hotplug aware.

Resolve MODPOST warnings similar to:

WARNING: vmlinux - Section mismatch: reference to .init.text:sysenter_setup from
 .text between 'identify_cpu' (at offset 0xc040a380) and 'detect_ht'

and

WARNING: vmlinux - Section mismatch: reference to .init.data:vsyscall_int80_end
from .text between 'sysenter_setup' (at offset 0xc041a269) and 'enable_sep_cpu'
WARNING: vmlinux - Section mismatch: reference to
.init.data:vsyscall_int80_start from .text between 'sysenter_setup' (at offset
0xc041a26e) and 'enable_sep_cpu'
WARNING: vmlinux - Section mismatch: reference to
.init.data:vsyscall_sysenter_end from .text between 'sysenter_setup' (at offset
0xc041a275) and 'enable_sep_cpu'
WARNING: vmlinux - Section mismatch: reference to
.init.data:vsyscall_sysenter_start from .text between 'sysenter_setup' (at
offset 0xc041a27a) and 'enable_sep_cpu'
Signed-off-by: NPrarit Bhargava <prarit@redhat.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

Add __init to probe_bigsmp.  All callers are __init and data being examined
is __initdata.

Resolves MODPOST warning similar to:

WARNING: vmlinux - Section mismatch: reference to .init.data: from .text between 'probe_bigsmp' (at offset 0xc0401e56) and 'init_apic_ldr'
Signed-off-by: NPrarit Bhargava <prarit@redhat.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

Hello,

This patch against 2.6.20-git14 makes the NMI watchdog use PERFSEL1/PERFCTR1
instead of PERFSEL0/PERFCTR0 on processors supporting Intel architectural
perfmon, such as Intel Core 2. Although all PMU events can work on
both counters, the Precise Event-Based Sampling (PEBS) requires that the
event be in PERFCTR0 to work correctly (see section 18.14.4.1 in the
IA32 SDM Vol 3b). This versions has 3 chunks compared to previous where
we had missed on check.

Changelog:
        - make the x86-64 NMI watchdog use PERFSEL1/PERFCTR1 instead of PERFSEL0/PERFCTR0
          on processors supporting the Intel architectural perfmon (e.g. Core 2 Duo).
          This allows PEBS to work when the NMI watchdog is active.
signed-off-by: Nstephane eranian <eranian@hpl.hp.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

Hello,

This patch against 2.6.20-git14 makes the NMI watchdog use PERFSEL1/PERFCTR1
instead of PERFSEL0/PERFCTR0 on processors supporting Intel architectural
perfmon, such as Intel Core 2. Although all PMU events can work on
both counters, the Precise Event-Based Sampling (PEBS) requires that the
event be in PERFCTR0 to work correctly (see section 18.14.4.1 in the
IA32 SDM Vol 3b).

A similar patch for x86-64 is to follow.

Changelog:
        - make the i386 NMI watchdog use PERFSEL1/PERFCTR1 instead of PERFSEL0/PERFCTR0
          on processors supporting the Intel architectural perfmon (e.g. Core 2 Duo).
          This allows PEBS to work when the NMI watchdog is active.
signed-off-by: Nstephane eranian <eranian@hpl.hp.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

Move prototypes into header files
Remove unneeded includes.
Signed-off-by: NAndi Kleen <ak@suse.de>

a userspace fault or a kernelspace fault which will result in the
immediate death of the process.  They should not be filled in as a
result of a kernelspace fault which can be fixed up.

Otherwise, if the process is handling SIGSEGV and examining the fault
information, this can result in the kernel space fault trashing the
previously stored fault information if it arrives between the
userspace fault happening and the SIGSEGV being delivered to the process.
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Acked-by: NJan Beulich <jbeulich@novell.com>
--
 arch/i386/kernel/traps.c   |   24 ++++++++++++++++++------
 arch/x86_64/kernel/traps.c |   30 +++++++++++++++++++++++-------
 2 files changed, 41 insertions(+), 13 deletions(-)

Signed-off-by: NAndi Kleen <ak@suse.de>

Signed-off-by: NJan Beulich <jbeulich@novell.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

Remove the assumption that if the first page of a legacy ROM is mapped,
it'll all be mapped. This'll also stop people reading this code from
wondering if they're looking at a bug...
Signed-off-by: NRene Herman <rene.herman@gmail.com>
Signed-off-by: NMartin Murray <murrayma@citi.umich.edu>
Signed-off-by: NAndi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Cc: Zachary Amsden <zach@vmware.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

The VIA C7 is a 686 (with TSC) that supports MMX, SSE and SSE2, it also has
a cache line length of 64 according to
http://www.digit-life.com/articles2/cpu/rmma-via-c7.html.  This patch sets
gcc to -march=686 and select s the correct cache shift.
Signed-off-by: NSimon Arlott <simon@fire.lp0.eu>
Signed-off-by: NAndi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

Eliminated the arch/i386/kernel/timers in 2.6.18, use clocksoures instead.
pit_latch_buggy was referred in timers/timer_tsc.c, and currently removed.
Therefore nobody refer it.

Until 2.6.17, MediaGX's TSC works correctly.  after 2.6.18, warned "TSC
appears to be running slowly.  Marking it as unstable".  So marked unstable
TSC when CS55x0.

Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAndi Kleen <ak@suse.de>