linux-toradex.git/arch/ia64/kernel/ivt.S, branch v4.9.54

ia64: move exports to definitions

2016-08-08T03:55:50+00:00

Here we have another kind of deviation from the default case -
a difference between exporting functions and non-functions.
EXPORT_DATA_SYMBOL... is really different from EXPORT_SYMBOL...
on ia64, and we need to use the right one when moving exports
from *.c where C compiler has the required information to
*.S, where we need to supply it manually.

parisc64 will be another one like that.

Tested-by: Tony Luck 
Signed-off-by: Al Viro

ia64: remove paravirt code

2015-06-10T21:26:32+00:00

All the ia64 pvops code is now dead code since both
xen and kvm support have been ripped out [0] [1]. Just
that no one had troubled to rip this stuff out. The only
useful remaining pieces were the old pvops docs but that
was recently also generalized and moved out from ia64 [2].

This has been run time tested on an ia64 Madison system.

[0] 003f7de625890 "KVM: ia64: remove" since v3.19-rc1
[1] d52eefb47d4eb "ia64/xen: Remove Xen support for ia64" since v3.14-rc1
[2] "virtual: Documentation: simplify and generalize paravirt_ops.txt"

Signed-off-by: Luis R. Rodriguez 
Signed-off-by: Tony Luck

ia64: expose number of page table levels on Kconfig level

2015-04-14T23:49:02+00:00

We would want to use number of page table level to define mm_struct.
Let's expose it as CONFIG_PGTABLE_LEVELS.

We need to define PGTABLE_LEVELS before sourcing init/Kconfig:
arch/Kconfig will define default value and it's sourced from init/Kconfig.

Signed-off-by: Kirill A. Shutemov 
Cc: Tony Luck 
Cc: Fenghua Yu 
Tested-by: Guenter Roeck 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[IA64] Change default PSR.ac from '1' to '0' (Fix erratum #237)

2014-04-16T17:20:34+00:00

April 2014 Itanium processor specification update:

http://www.intel.com/content/www/us/en/processors/itanium/itanium-specification-update.html

describes this erratum:

=========================================================================
237. Under a complex set of conditions, store to load forwarding for a
sub 8-byte load may complete incorrectly

Problem: A load instruction may complete incorrectly when a code sequence
using 4-byte or smaller load and store operations to the same address
is executed in combination with specific timing of all the following
concurrent conditions: store to load forwarding, alignment checking
enabled, a mis-predicted branch, and complex cache utilization activity.

Implication: The affected sub 8-byte instruction may complete
incorrectly resulting in unpredictable system behavior. There is an
extremely low probability of exposure due to the significant number of
complex microarchitectural concurrent conditions required to encounter
the erratum.

Workaround: Set PSR.ac = 0 to completely avoid the erratum. Disabling
Hyper-Threading will significantly reduce exposure to the conditions
that contribute to encountering the erratum.

Status: See the Summary Table of Changes for the affected steppings.
=========================================================================

[Table of changes essentially lists all models from McKinley to Tukwila]

The PSR.ac bit controls whether the processor will always generate
an unaligned reference trap (0x5a00) for a misaligned data access
(when PSR.ac=1) or if it will let the access succeed when running
on a cpu that implements logic to handle some unaligned accesses.

Way back in 2008 in commit b704882e70d87d7f56db5ff17e2253f3fa90e4f3
  [IA64] Rationalize kernel mode alignment checking
we made the decision to always enable strict checking. We were
already doing so in trap/interrupt context because the common
preamble code set this bit - but the rest of supervisor code
(and by inheritance user code) ran with PSR.ac=0.

We now reverse that decision and set PSR.ac=0 everywhere in the
kernel (also inherited by user processes). This will avoid the
erratum using the method described in the Itanium specification
update.  Net effect for users is that the processor will handle
unaligned access when it can (typically with a tiny performance
bubble in the pipeline ... but much less invasive than taking a
trap and having the OS perform the access).

Signed-off-by: Tony Luck

cputime: Generic on-demand virtual cputime accounting

2013-01-27T18:23:27+00:00

If we want to stop the tick further idle, we need to be
able to account the cputime without using the tick.

Virtual based cputime accounting solves that problem by
hooking into kernel/user boundaries.

However implementing CONFIG_VIRT_CPU_ACCOUNTING require
low level hooks and involves more overhead. But we already
have a generic context tracking subsystem that is required
for RCU needs by archs which plan to shut down the tick
outside idle.

This patch implements a generic virtual based cputime
accounting that relies on these generic kernel/user hooks.

There are some upsides of doing this:

- This requires no arch code to implement CONFIG_VIRT_CPU_ACCOUNTING
if context tracking is already built (already necessary for RCU in full
tickless mode).

- We can rely on the generic context tracking subsystem to dynamically
(de)activate the hooks, so that we can switch anytime between virtual
and tick based accounting. This way we don't have the overhead
of the virtual accounting when the tick is running periodically.

And one downside:

- There is probably more overhead than a native virtual based cputime
accounting. But this relies on hooks that are already set anyway.

Signed-off-by: Frederic Weisbecker 
Cc: Andrew Morton 
Cc: Ingo Molnar 
Cc: Li Zhong 
Cc: Namhyung Kim 
Cc: Paul E. McKenney 
Cc: Paul Gortmaker 
Cc: Peter Zijlstra 
Cc: Steven Rostedt 
Cc: Thomas Gleixner

Disintegrate asm/system.h for IA64

2012-03-28T17:30:02+00:00

Disintegrate asm/system.h for IA64.

Signed-off-by: David Howells 
Acked-by: Tony Luck 
cc: linux-ia64@vger.kernel.org

Merge branch 'for-35' of git://repo.or.cz/linux-kbuild

2010-06-01T15:55:52+00:00

* 'for-35' of git://repo.or.cz/linux-kbuild: (81 commits)
  kbuild: Revert part of e8d400a to resolve a conflict
  kbuild: Fix checking of scm-identifier variable
  gconfig: add support to show hidden options that have prompts
  menuconfig: add support to show hidden options which have prompts
  gconfig: remove show_debug option
  gconfig: remove dbg_print_ptype() and dbg_print_stype()
  kconfig: fix zconfdump()
  kconfig: some small fixes
  add random binaries to .gitignore
  kbuild: Include gen_initramfs_list.sh and the file list in the .d file
  kconfig: recalc symbol value before showing search results
  .gitignore: ignore *.lzo files
  headerdep: perlcritic warning
  scripts/Makefile.lib: Align the output of LZO
  kbuild: Generate modules.builtin in make modules_install
  Revert "kbuild: specify absolute paths for cscope"
  kbuild: Do not unnecessarily regenerate modules.builtin
  headers_install: use local file handles
  headers_check: fix perl warnings
  export_report: fix perl warnings
  ...

Rename .text.ivt to .text..ivt.

2010-03-03T10:26:00+00:00

Signed-off-by: Denys Vlasenko 
Signed-off-by: Michal Marek

[IA64] Remove COMPAT_IA32 support

2010-02-08T18:42:17+00:00

This has been broken since May 2008 when Al Viro killed altroot support.
Since nobody has complained, it would appear that there are no users of
this code (A plausible theory since the main OSVs that support ia64 prefer
to use the IA32-EL software emulation).

Signed-off-by: Tony Luck

ia64/pv_ops: paravirtualize mov = ar.itc.

2009-03-26T17:50:22+00:00

paravirtualize mov reg = ar.itc.

Signed-off-by: Isaku Yamahata 
Signed-off-by: Tony Luck