* 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86-64: move clts into batch cpu state updates when preloading fpu
x86-64: move unlazy_fpu() into lazy cpu state part of context switch
x86-32: make sure clts is batched during context switch
x86: split out core __math_state_restore
This function measures whether the FPU/SSE state can be touched in
interrupt context. If the interrupted code is in user space or has no
valid FPU/SSE context (CR0.TS == 1), FPU/SSE state can be used in IRQ
or soft_irq context too.
This is used by AES-NI accelerated AES implementation and PCLMULQDQ
accelerated GHASH implementation.
v3:
- Renamed to irq_fpu_usable to reflect the purpose of the function.
v2:
- Renamed to irq_is_fpu_using to reflect the real situation.
Signed-off-by: Huang Ying <ying.huang@intel.com>
CC: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Split the core fpu state restoration out into __math_state_restore, which
assumes that cr0.TS is clear and that the fpu context has been initialized.
This will be used during context switch. There are two reasons this is
desireable:
- There's a small clarification. When __switch_to() calls math_state_restore,
it relies on the fact that tsk_used_math() returns true, and so will
never do a blocking init_fpu(). __math_state_restore() does not have
(or need) that logic, so the question never arises.
- It allows the clts() to be moved earler in __switch_to() so it can be performed
while cpu context updates are batched (will be done in a later patch).
[ Impact: refactor code to make reuse cleaner; no functional change ]
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Alok Kataria <akataria@vmware.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86: Clear TS in irq_ts_save() when in an atomic section
x86: Detect use of extended APIC ID for AMD CPUs
x86: memtest: remove 64-bit division
x86, UV: Fix macros for multiple coherency domains
x86: Fix non-lazy GS handling in sys_vm86()
x86: Add quirk for reboot stalls on a Dell Optiplex 360
x86: Fix UV BAU activation descriptor init
Impact: cleanup
The comments which fxrstor_checking and fxsave_uset refer to is
now in fxsave. Change the comments appropriately.
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Cc: Jiri Slaby <jirislaby@gmail.com>
LKML-Reference: <1239190320-23952-3-git-send-email-jirislaby@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup
On x86_32, separate f*rstor to an inline function which makes
restore_fpu_checking the same on both platforms -> move it
outside the ifdefs.
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
LKML-Reference: <1239190320-23952-2-git-send-email-jirislaby@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup, prepare FPU code unificaton
Like on x86_64, return an error from restore_fpu and kill the task
if it fails.
Also rename restore_fpu to restore_fpu_checking which allows ifdefs
to be removed in math_state_restore().
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
LKML-Reference: <1239190320-23952-1-git-send-email-jirislaby@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: fix math-emu related crash while using GDB/ptrace
init_fpu() calls finit to initialize a task's xstate, while finit always
works on the current task. If we use PTRACE_GETFPREGS on another
process and both processes did not already use floating point, we get
a null pointer exception in finit.
This patch creates a new function finit_task that takes a task_struct
parameter. finit becomes a wrapper that simply calls finit_task with
current. On the plus side this avoids many calls to get_current which
would each resolve to an inline assembler mov instruction.
An empty finit_task has been added to i387.h to avoid linker errors in
case the compiler still emits the call in init_fpu when
CONFIG_MATH_EMULATION is not defined.
The declaration of finit in i387.h has been removed as the remaining
code using this function gets its prototype from fpu_proto.h.
Signed-off-by: Daniel Glöckner <dg@emlix.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: "Pallipadi Venkatesh" <venkatesh.pallipadi@intel.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Bill Metzenthen <billm@melbpc.org.au>
LKML-Reference: <E1Lew31-0004il-Fg@mailer.emlix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Change header guards named "ASM_X86__*" to "_ASM_X86_*" since:
a. the double underscore is ugly and pointless.
b. no leading underscore violates namespace constraints.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
