linux_dsm_epyc7002/arch
Dave Hansen 1f96b1efba x86/fpu: Add placeholder for 'Processor Trace' XSAVE state
There is an XSAVE state component for Intel Processor Trace (PT).
But, we do not currently use it.

We add a placeholder in the code for it so it is not a mystery and
also so we do not need an explicit enum initialization for Protection
Keys in a moment.

Why don't we use it?

We might end up using this at _some_ point in the future.  But,
this is a "system" state which requires using the currently
unsupported XSAVES feature.  Unlike all the other XSAVE states,
PT state is also not directly tied to a thread.  You might
context-switch between threads, but not want to change any of the
PT state.  Or, you might switch between threads, and *do* want to
change PT state, all depending on what is being traced.

We currently just manually set some MSRs to do this PT context
switching, and it is unclear whether replacing our direct MSR use
with XSAVE will be a net win or loss, both in code complexity and
performance.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: fenghua.yu@intel.com
Cc: linux-mm@kvack.org
Cc: yu-cheng.yu@intel.com
Link: http://lkml.kernel.org/r/20160212210158.5E4BCAE2@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-16 10:11:13 +01:00
..
alpha dma-mapping: always provide the dma_map_ops based implementation 2016-01-20 17:09:18 -08:00
arc ARC fixes for 4.5 2016-02-13 08:18:21 -08:00
arm Merge branch 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm 2016-02-14 10:46:47 -08:00
arm64 Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-02-14 11:49:30 -08:00
avr32 dma-mapping: always provide the dma_map_ops based implementation 2016-01-20 17:09:18 -08:00
blackfin dma-mapping: always provide the dma_map_ops based implementation 2016-01-20 17:09:18 -08:00
c6x dma-mapping: always provide the dma_map_ops based implementation 2016-01-20 17:09:18 -08:00
cris mm/gup: Switch all callers of get_user_pages() to not pass tsk/mm 2016-02-16 10:11:12 +01:00
frv dma-mapping: always provide the dma_map_ops based implementation 2016-01-20 17:09:18 -08:00
h8300 Merge branch 'akpm' (patches from Andrew) 2016-01-21 12:32:08 -08:00
hexagon dma-mapping: always provide the dma_map_ops based implementation 2016-01-20 17:09:18 -08:00
ia64 mm/gup: Switch all callers of get_user_pages() to not pass tsk/mm 2016-02-16 10:11:12 +01:00
m32r m32r: fix build failure due to SMP and MMU 2016-02-05 18:10:40 -08:00
m68k dma-mapping: always provide the dma_map_ops based implementation 2016-01-20 17:09:18 -08:00
metag dma-mapping: always provide the dma_map_ops based implementation 2016-01-20 17:09:18 -08:00
microblaze dma-mapping: always provide the dma_map_ops based implementation 2016-01-20 17:09:18 -08:00
mips mm/gup: Switch all callers of get_user_pages() to not pass tsk/mm 2016-02-16 10:11:12 +01:00
mn10300 dma-mapping: always provide the dma_map_ops based implementation 2016-01-20 17:09:18 -08:00
nios2 dma-mapping: always provide the dma_map_ops based implementation 2016-01-20 17:09:18 -08:00
openrisc dma-mapping: always provide the dma_map_ops based implementation 2016-01-20 17:09:18 -08:00
parisc dma-mapping: always provide the dma_map_ops based implementation 2016-01-20 17:09:18 -08:00
powerpc powerpc fixes for 4.5 2016-01-29 16:10:16 -08:00
s390 mm/gup: Switch all callers of get_user_pages() to not pass tsk/mm 2016-02-16 10:11:12 +01:00
score
sh mm/gup: Switch all callers of get_user_pages() to not pass tsk/mm 2016-02-16 10:11:12 +01:00
sparc mm/gup: Switch all callers of get_user_pages() to not pass tsk/mm 2016-02-16 10:11:12 +01:00
tile dma-mapping: always provide the dma_map_ops based implementation 2016-01-20 17:09:18 -08:00
um um: asm/page.h: remove the pte_high member from struct pte_t 2016-02-05 18:10:40 -08:00
unicore32 dma-mapping: always provide the dma_map_ops based implementation 2016-01-20 17:09:18 -08:00
x86 x86/fpu: Add placeholder for 'Processor Trace' XSAVE state 2016-02-16 10:11:13 +01:00
xtensa dma-mapping: remove <asm-generic/dma-coherent.h> 2016-01-20 17:09:18 -08:00
.gitignore
Kconfig dma-mapping: always provide the dma_map_ops based implementation 2016-01-20 17:09:18 -08:00