Commit Graph

79906 Commits

Author SHA1 Message Date
Roland McGrath
e39c289141 x86: ptrace FLAG_MASK cleanup
This cleans up the FLAG_MASK macro to use symbolic constants instead of a
magic number.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:01 +01:00
Roland McGrath
d52e9d690f x86: ptrace_32 renamed
This renames ptrace_32.c back to ptrace.c, in preparation
for merging the 32/64 versions of these files.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:01 +01:00
Roland McGrath
0f5340933f x86: x86-32 thread_struct.debugreg
This replaces the debugreg[7] member of thread_struct with individual
members debugreg0, etc.  This saves two words for the dummies 4 and 5,
and harmonizes the code between 32 and 64.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:59 +01:00
Roland McGrath
d277fb89df x86: x86-64 ia32 ptrace get/putreg32 current task
This generalizes the getreg32 and putreg32 functions so they can be used on
the current task, as well as on a task stopped in TASK_TRACED and switched
off.  This lays the groundwork to share this code for all kinds of
user-mode machine state access, not just ptrace.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:58 +01:00
Roland McGrath
5fd4d16bd5 x86: x86-32 ptrace get/putreg current task
This generalizes the getreg and putreg functions so they can be used on the
current task, as well as on a task stopped in TASK_TRACED and switched off.
This lays the groundwork to share this code for all kinds of user-mode
machine state access, not just ptrace.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:58 +01:00
Roland McGrath
ce90f34085 x86: x86-64 ptrace get/putreg current task
This generalizes the getreg and putreg functions so they can be used on the
current task, as well as on a task stopped in TASK_TRACED and switched off.
This lays the groundwork to share this code for all kinds of user-mode
machine state access, not just ptrace.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:58 +01:00
Roland McGrath
9e714bed64 x86: x86-32 ptrace whitespace
This canonicalizes the indentation in the getreg and putreg functions.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:58 +01:00
Roland McGrath
80976c0867 x86: x86-64 ptrace whitespace
This canonicalizes the indentation in the getreg and putreg functions.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:58 +01:00
Roland McGrath
ff14c6164b x86: x86-64 ia32 ptrace pt_regs cleanup
This cleans up the getreg32/putreg32 functions to use struct pt_regs in a
straightforward fashion, instead of equivalent ugly pointer arithmetic.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:57 +01:00
Roland McGrath
35d0991ffa x86: eflags enum
This removes the EF_* enum from <asm/ptrace.h>.  It is no longer used,
and duplicates the X86_EFLAGS_* constants from <asm/processor-flags.h>.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:57 +01:00
Roland McGrath
a46ff73d53 x86: setup64 eflags constants
This cleans up arch/x86/kernel/setup64.c to use the X86_EFLAGS_* constants
from <asm/processor-flags.h> instead of the EF_* enum in <asm/ptrace.h>.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:57 +01:00
H. Peter Anvin
742fa54a62 x86: use generic register names in struct sigcontext
Switch struct sigcontext (defined in <asm/sigcontext*.h>) to using
register names withut e- or r-prefixes for both 32- and 64-bit x86.
This is intended as a preliminary step in unifying this code between
architectures.

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>
2008-01-30 13:30:56 +01:00
H. Peter Anvin
153d5f2e57 x86: use generic register names in struct user_regs_struct
Switch struct user_regs_struct (defined in <asm/user.h>, which is no
longer exported to userspace) to using register names without e- or
r-prefixes for both 32 and 64 bit x86.  This is intended as a
preliminary step in unifying this code between architectures.

Also, be a bit more strict in truncating 32-bit "extended" segment
register values to 16 bits.

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>
2008-01-30 13:30:56 +01:00
H. Peter Anvin
65ea5b0349 x86: rename the struct pt_regs members for 32/64-bit consistency
We have a lot of code which differs only by the naming of specific
members of structures that contain registers.  In order to enable
additional unifications, this patch drops the e- or r- size prefix
from the register names in struct pt_regs, and drops the x- prefixes
for segment registers on the 32-bit side.

This patch also performs the equivalent renames in some additional
places that might be candidates for unification in the future.

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>
2008-01-30 13:30:56 +01:00
Jeremy Fitzhardinge
53756d3722 x86: add set/clear_cpu_cap operations
The patch to suppress bitops-related warnings added a pile of ugly
casts.  Many of these were related to the management of x86 CPU
capabilities.  Clean these up by adding specific set/clear_cpu_cap
macros, and use them consistently.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Andi Kleen <ak@suse.de>

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:55 +01:00
Jeremy Fitzhardinge
5548fecdff x86: clean up bitops-related warnings
Add casts to appropriate places to silence spurious bitops warnings.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Andi Kleen <ak@suse.de>

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:55 +01:00
Jeremy Fitzhardinge
1c54d77078 x86: partial unification of asm-x86/bitops.h
This unifies the set/clear/test bit functions of asm/bitops.h.

I have not attempted to merge the bit-finding functions, since they
rely on the machine word size and can't be easily restructured to work
generically without a lot of #ifdefs.  In particular, the 64-bit code
can assume the presence of conditional move instructions, whereas
32-bit needs to be more careful.

The inline assembly for the bit operations has been changed to remove
explicit sizing hints on the instructions, so the assembler will pick
the appropriate instruction forms depending on the architecture and
the context.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:55 +01:00
Mike Travis
7bf0c23ed2 x86: prevent dereferencing non-allocated per_cpu variables
'for_each_possible_cpu(i)' when there's a _remote possibility_ of
dereferencing a non-allocated per_cpu variable involved.

All files except mm/vmstat.c are x86 arch.

Thanks to pageexec@freemail.hu for pointing this out.

Signed-off-by: Mike Travis <travis@sgi.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: <pageexec@freemail.hu>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:55 +01:00
Roland McGrath
0fa376e027 x86: PTRACE_SINGLEBLOCK
This adds the PTRACE_SINGLEBLOCK request on x86, matching the ia64 feature.
The implementation comes from the generic ptrace code and relies on the
low-level machine support provided by arch_has_block_step() et al.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:55 +01:00
Roland McGrath
1ecc798c67 x86: debugctlmsr kprobes
This adjusts the x86 kprobes implementation to cope with per-thread
MSR_IA32_DEBUGCTLMSR being set for user mode.  I haven't delved deep
enough into the kprobes code to be really sure this covers all the
cases where the user-mode BTF setting needs to be cleared or restored.
It looks about right to me.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:54 +01:00
Roland McGrath
10faa81e10 x86: debugctlmsr arch_has_block_step
This implements user-mode step-until-branch on x86 using the BTF bit
in MSR_IA32_DEBUGCTLMSR.  It's just like single-step, only less so.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:54 +01:00
Roland McGrath
7e9916040b x86: debugctlmsr context switch
This adds low-level support for a per-thread value of MSR_IA32_DEBUGCTLMSR.
The per-thread value is switched in when TIF_DEBUGCTLMSR is set.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:54 +01:00
Roland McGrath
0a049bb0ab x86: debugctlmsr kconfig
This adds the (internal) Kconfig macro CONFIG_X86_DEBUGCTLMSR,
to be defined when configuring to support only hardware that
definitely supports MSR_IA32_DEBUGCTLMSR with the BTF flag.

The Intel documentation says "P6 family" and later processors all have it.
I think the Kconfig dependencies are right to have it set for those and
unset for others (i.e., when 586 and earlier are supported).

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:54 +01:00
Roland McGrath
d2499d8b6c x86: debugctlmsr constants
This adds constant macros for a few of the bits in MSR_IA32_DEBUGCTLMSR.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:54 +01:00
Roland McGrath
5b88abbf77 ptrace: generic PTRACE_SINGLEBLOCK
This makes ptrace_request handle PTRACE_SINGLEBLOCK along with
PTRACE_CONT et al.  The new generic code makes use of the
arch_has_block_step macro and generic entry points on machines
that define them.

[ mingo@elte.hu: bugfix ]

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:53 +01:00
Roland McGrath
dc802c2d2e ptrace: arch_has_block_step
This defines the new macro arch_has_block_step() in linux/ptrace.h, a
default for when asm/ptrace.h does not define it.  This is the analog
of arch_has_single_step() for step-until-branch on machines that have
it.  It declares the new user_enable_block_step function, which goes
with the existing user_enable_single_step and user_disable_single_step.
This is not used yet, but paves the way to harmonize on this interface
for the arch-specific calls on all machines.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:53 +01:00
Roland McGrath
d9771e8c50 x86: x86-32 ptrace debugreg cleanup
This cleans up the 32-bit ptrace code to separate the guts of the
debug register access from the implementation of PTRACE_PEEKUSR and
PTRACE_POKEUSR.  The new functions ptrace_[gs]et_debugreg match the
new 64-bit entry points for parity, but they don't need to be global.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:52 +01:00
Roland McGrath
d0f0817582 x86: x86-64 ia32 ptrace debugreg cleanup
This cleans up the ia32 compat ptrace code to use shared code from
native ptrace for the implementation guts of debug register access.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:52 +01:00
Roland McGrath
962ff3804d x86: x86-64 ptrace debugreg cleanup
This cleans up the 64-bit ptrace code to separate the guts of the
debug register access from the implementation of PTRACE_PEEKUSR and
PTRACE_POKEUSR.  The new functions ptrace_[gs]et_debugreg are made
global so that the ia32 code can later be changed to call them too.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:52 +01:00
Roland McGrath
e4aed6cc45 x86-64 ptrace: use task_pt_regs
This cleans up the 64-bit ptrace code to use task_pt_regs instead of its
own redundant code that does the same thing a different way.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:52 +01:00
Roland McGrath
62a97d447b x86-32 ptrace: use task_pt_regs
This cleans up the 32-bit ptrace code to use task_pt_regs instead of its
own redundant code that does the same thing a different way.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:52 +01:00
Roland McGrath
d6f4fb7558 powerpc: ptrace generic resume
This removes the handling for PTRACE_CONT et al from the powerpc
ptrace code, so it uses the new generic code via ptrace_request.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:51 +01:00
Roland McGrath
2a84b0d719 powerpc: arch_has_single_step
This defines the new standard arch_has_single_step macro.  It makes the
existing set_single_step and clear_single_step entry points global, and
renames them to the new standard names user_enable_single_step and
user_disable_single_step, respectively.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:51 +01:00
Roland McGrath
227195d4a6 x86-32: ptrace generic resume
This removes the handling for PTRACE_CONT et al from the 32-bit
ptrace code, so it uses the new generic code via ptrace_request.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:51 +01:00
Roland McGrath
18982c158f x86-64: ptrace generic resume
This removes the handling for PTRACE_CONT et al from the 64-bit
ptrace code, so it uses the new generic code via ptrace_request.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:51 +01:00
Roland McGrath
36df29d799 ptrace: generic resume
This makes ptrace_request handle all the ptrace requests that wake
up the traced task.  These do low-level ptrace implementation magic
that is not arch-specific and should be kept out of arch code.  The
implementations on each arch usually do the same thing.  The new
generic code makes use of the arch_has_single_step macro and generic
entry points to handle PTRACE_SINGLESTEP.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:51 +01:00
Roland McGrath
e1f287735c x86 single_step: TIF_FORCED_TF
This changes the single-step support to use a new thread_info flag
TIF_FORCED_TF instead of the PT_DTRACE flag in task_struct.ptrace.
This keeps arch implementation uses out of this non-arch field.

This changes the ptrace access to eflags to mask TF and maintain
the TIF_FORCED_TF flag directly if userland sets TF, instead of
relying on ptrace_signal_deliver.  The 64-bit and 32-bit kernels
are harmonized on this same behavior.  The ptrace_signal_deliver
approach works now, but this change makes the low-level register
access code reliable when called from different contexts than a
ptrace stop, which will be possible in the future.

The 64-bit do_debug exception handler is also changed not to clear TF
from user-mode registers.  This matches the 32-bit kernel's behavior.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:50 +01:00
Roland McGrath
7122ec8158 x86: single_step: share code
This removes the single-step code from ptrace_32.c and uses the step.c code
shared with the 64-bit kernel.  The two versions of the code were nearly
identical already, so the shared code has only a couple of simple #ifdef's.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:50 +01:00
Roland McGrath
5f76cb1f6c x86: single_step 0xf0
This fixes the 64-bit single-step handling code's instruction
decoder to grok the 0xf0 (lock) prefix, which the 32-bit code
already does correctly.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:50 +01:00
Roland McGrath
3f80c1adc9 x86: single_step segment macros
This cleans up the single-step code to use the asm/segment.h macros
for segment selector magic bits, rather than its own constant.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:50 +01:00
Roland McGrath
fa1e03eae2 x86: single_step moved
This moves the single-step support code from ptrace_64.c into a new file
step.c, verbatim.  This paves the way for consolidating this code between
64-bit and 32-bit versions.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:50 +01:00
Roland McGrath
7f232343e0 x86: arch_has_single_step
This defines the new standard arch_has_single_step macro.  It makes the
existing set_singlestep and clear_singlestep entry points global, and
renames them to the new standard names user_enable_single_step and
user_disable_single_step, respectively.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:48 +01:00
Roland McGrath
77c03dcd44 x86: remove TRAP_FLAG
This gets rid of the local constant macro TRAP_FLAG.
It's redundant with the public constant macro X86_EFLAGS_TF.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:48 +01:00
Roland McGrath
2608a6584a x86: segment selector macros
This copies into asm-x86/segment_64.h some macros from asm-x86/segment_32.h
for dissecting segment selectors.  This lets other code use these macros
uniformly on 32/64-bit rather than duplicating the constants elsewhere.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:48 +01:00
Roland McGrath
fb7fa8f174 ptrace: arch_has_single_step
This defines the new macro arch_has_single_step() in linux/ptrace.h, a
default for when asm/ptrace.h does not define it.  It declares the new
user_enable_single_step and user_disable_single_step functions.
This is not used yet, but paves the way to harmonize on this interface
for the arch-specific calls on all machines.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:47 +01:00
Andrew Morton
022eb43419 x86: kmap_atomic() debugging
[ mingo@elte.hu: cleanups and made dependent on CONFIG_DEBUG_HIGHMEM.

  this caught a handful of bugs already, so lets apply it. If it gets
  things wrong we'll disable it. ]

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:47 +01:00
Mathieu Desnoyers
2c0b8a7578 x86: fall back on interrupt disable in cmpxchg8b on 80386 and 80486
Actually, on 386, cmpxchg and cmpxchg_local fall back on
cmpxchg_386_u8/16/32: it disables interruptions around non atomic
updates to mimic the cmpxchg behavior.

The comment:
/* Poor man's cmpxchg for 386. Unsuitable for SMP */

already present in cmpxchg_386_u32 tells much about how this cmpxchg
implementation should not be used in a SMP context. However, the cmpxchg_local
can perfectly use this fallback, since it only needs to be atomic wrt the local
cpu.

This patch adds a cmpxchg_486_u64 and uses it as a fallback for cmpxchg64
and cmpxchg64_local on 80386 and 80486.

Q:
but why is it called cmpxchg_486 when the other functions are called

A:
Because the standard cmpxchg is missing only on 386, but cmpxchg8b is
missing both on 386 and 486.

Citing Intel's Instruction set reference:

cmpxchg:
This instruction is not supported on Intel processors earlier than the
Intel486 processors.

cmpxchg8b:
This instruction encoding is not supported on Intel processors earlier
than the Pentium processors.

Q:
What's the reason to have cmpxchg64_local on 32 bit architectures?
Without that need all this would just be a few simple defines.

A:
cmpxchg64_local on 32 bits architectures takes unsigned long long
parameters, but cmpxchg_local only takes longs. Since we have cmpxchg8b
to execute a 8 byte cmpxchg atomically on pentium and +, it makes sense
to provide a flavor of cmpxchg and cmpxchg_local using this instruction.

Also, for 32 bits architectures lacking the 64 bits atomic cmpxchg, it
makes sense _not_ to define cmpxchg64 while cmpxchg could still be
available.

Moreover, the fallback for cmpxchg8b on i386 for 386 and 486 is a

However, cmpxchg64_local will be emulated by disabling interrupts on all
architectures where it is not supported atomically.

Therefore, we *could* turn cmpxchg64_local into a cmpxchg_local, but it
would make the 386/486 fallbacks ugly, make its design different from
cmpxchg/cmpxchg64 (which really depends on atomic operations and cannot
be emulated) and require the __cmpxchg_local to be expressed as a macro
rather than an inline function so the parameters would not be fixed to
unsigned long long in every case.

So I think cmpxchg64_local makes sense there, but I am open to
suggestions.

Q:
Are there any callers?

A:
I am actually using it in LTTng in my timestamping code. I use it to
work around CPUs with asynchronous TSCs. I need to update 64 bits
values atomically on this 32 bits architecture.

Changelog:
- Ran though checkpatch.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:47 +01:00
Ralf Baechle
5f627f8e12 mips, x86: optimize the i8259 code a bit
The timer code always calls the clock_event_device set_net_event and
set_mode methods with interrupts disabled, so no need to use
spin_lock_irqsave / spin_unlock_irqrestore for those.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Acked-by:Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:47 +01:00
Christoph Lameter
b263295dbf x86: 64-bit, make sparsemem vmemmap the only memory model
Use sparsemem as the only memory model for UP, SMP and NUMA.  Measurements
indicate that DISCONTIGMEM has a higher overhead than sparsemem.  And
FLATMEMs benefits are minimal.  So I think its best to simply standardize
on sparsemem.

Results of page allocator tests (test can be had via git from slab git
tree branch tests)

Measurements in cycle counts. 1000 allocations were performed and then the
average cycle count was calculated.

Order	FlatMem	Discontig	SparseMem
0	  639	  665		  641
1	  567	  647		  593
2	  679	  774		  692
3	  763	  967		  781
4	  961	 1501		  962
5	 1356	 2344		 1392
6	 2224	 3982		 2336
7	 4869	 7225		 5074
8	12500	14048		12732
9	27926	28223		28165
10	58578	58714		58682

(Note that FlatMem is an SMP config and the rest NUMA configurations)

Memory use:

SMP Sparsemem
-------------

Kernel size:

   text    data     bss     dec     hex filename
3849268  397739 1264856 5511863  541ab7 vmlinux

             total       used       free     shared    buffers     cached
Mem:       8242252      41164    8201088          0        352      11512
-/+ buffers/cache:      29300    8212952
Swap:      9775512          0    9775512

SMP Flatmem
-----------

Kernel size:

   text    data     bss     dec     hex filename
3844612  397739 1264536 5506887  540747 vmlinux

So 4.5k growth in text size vs. FLATMEM.

             total       used       free     shared    buffers     cached
Mem:       8244052      40544    8203508          0        352      11484
-/+ buffers/cache:      28708    8215344

2k growth in overall memory use after boot.

NUMA discontig:

   text    data     bss     dec     hex filename
3888124  470659 1276504 5635287  55fcd7 vmlinux

             total       used       free     shared    buffers     cached
Mem:       8256256      56908    8199348          0        352      11496
-/+ buffers/cache:      45060    8211196
Swap:      9775512          0    9775512

NUMA sparse:

   text    data     bss     dec     hex filename
3896428  470659 1276824 5643911  561e87 vmlinux

8k text growth. Given that we fully inline virt_to_page and friends now
that is rather good.

             total       used       free     shared    buffers     cached
Mem:       8264720      57240    8207480          0        352      11516
-/+ buffers/cache:      45372    8219348
Swap:      9775512          0    9775512

The total available memory is increased by 8k.

This patch makes sparsemem the default and removes discontig and
flatmem support from x86.

[ akpm@linux-foundation.org: allnoconfig build fix ]

Acked-by: Andi Kleen <ak@suse.de>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:47 +01:00
Borislav Petkov
4ebd1290ba x86: vmlinux_32.lds.S: remove repeated comment from the x86-32 linker script
Remove repeated comment from the linker script for the x86-32 target.

Signed-off-by: Borislav Petkov <bbpetkov@yahoo.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:46 +01:00