commit c434b7a6ae
(x86: avoid wasting IRQs for PCI devices)
created a concept of "IRQ compression" on i386
to conserve IRQ numbers on systems with many
sparsely populated IO APICs.
The same scheme was also added to x86_64,
but later removed when x86_64 recieved an IRQ over-haul
that made it unnecessary -- including per-CPU
IRQ vectors that greatly increased the IRQ capacity
on the machine.
i386 has not received the analogous over-haul,
and thus a previous attempt to delete IRQ compression
from i386 was rejected on the theory that there may
exist machines that actually need it. The fact is
that the author of IRQ compression patch was unable
to confirm the actual existence of such a system.
As a result, all i386 kernels with IOAPIC support
pay the following:
1. confusion
IRQ compression re-names the traditional IOAPIC
pin numbers (aka ACPI GSI's) into sequential IRQ #s:
ACPI: PCI Interrupt 0000:00:1c.0[A] -> GSI 20 (level, low) -> IRQ 16
ACPI: PCI Interrupt 0000:00:1c.1[B] -> GSI 21 (level, low) -> IRQ 17
ACPI: PCI Interrupt 0000:00:1c.2[C] -> GSI 22 (level, low) -> IRQ 18
ACPI: PCI Interrupt 0000:00:1c.3[D] -> GSI 23 (level, low) -> IRQ 19
ACPI: PCI Interrupt 0000:00:1c.4[A] -> GSI 20 (level, low) -> IRQ 16
This makes /proc/interrupts look different
depending on system configuration and device probe order.
It is also different than the x86_64 kernel running
on the exact same system. As a result, programmers
get confused when comparing systems.
2. complexity
The IRQ code in Linux is already overly complex,
and IRQ compression makes it worse. There have
already been two bug workarounds related to IRQ
compression -- the IRQ0 timer workaround and
the VIA PCI IRQ workaround.
3. size
All i386 kernels with IOAPIC support contain an int[4096] --
a 4 page array to contain the renamed IRQs.
So while the irq compression code on i386 should really
be deleted -- even before merging the x86_64 irq-overhaul,
this patch simply disables it on all high volume systems
to avoid problems #1 and #2 on most all i386 systems.
A large system with pin numbers >=64 will still have compression
to conserve limited IRQ numbers for sparse IOAPICS. However,
the vast majority of the planet, those with only pin numbers < 64
will use an identity GSI -> IRQ mapping.
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
This changes size-specific register names (eip/rip, esp/rsp, etc.) to
generic names in the thread and tss structures.
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>
This removes the old separate 64-bit and ia32 ptrace source files.
They are no longer used.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This switches over the 64-bit build to use the shared ptrace code,
instead of the old ptrace_64.c and arch/x86/ia32/ptrace32.c code.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This moves the sys32_ptrace code into arch/x86/kernel/ptrace.c,
verbatim except for a few hard-coded sizes replaced with sizeof.
Here this code can use the shared local functions in this file.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This reimplements the 64-bit IA32-emulation register access
functions in arch/x86/kernel/ptrace.c, where they can share
some guts with the native access functions directly.
These functions are not used yet, but this paves the way to move
IA32 ptrace support into this file to share its local functions.
[akpm@linuxfoundation.org: Build fix]
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This moves the 64-bit syscall tracing functions into ptrace.c,
so that ptrace_64.c becomes entirely obsolete.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This adds 64-bit support to arch_ptrace in arch/x86/kernel/ptrace.c,
so this function can be used for native ptrace on both 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>
This merges 64-bit support into the low-level register access
functions in arch/x86/kernel/ptrace.c, paving the way to share
this file between 32-bit and 64-bit builds.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This cleans up the getreg/putreg functions to move the special cases
(segment registers and eflags) out into their own subroutines.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
