aboutsummaryrefslogtreecommitdiffstats
path: root/Documentation/features/sched/membarrier-sync-core/arch-support.txt
blob: 0f419ecfbce6492e93f2ac26712e1327019f8e6d (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
#
# Feature name:          membarrier-sync-core
#         Kconfig:       ARCH_HAS_MEMBARRIER_SYNC_CORE
#         description:   arch supports core serializing membarrier
#
# Architecture requirements
#
# * arm64
#
# Rely on eret context synchronization when returning from IPI handler, and
# when returning to user-space.
#
# * x86
#
# x86-32 uses IRET as return from interrupt, which takes care of the IPI.
# However, it uses both IRET and SYSEXIT to go back to user-space. The IRET
# instruction is core serializing, but not SYSEXIT.
#
# x86-64 uses IRET as return from interrupt, which takes care of the IPI.
# However, it can return to user-space through either SYSRETL (compat code),
# SYSRETQ, or IRET.
#
# Given that neither SYSRET{L,Q}, nor SYSEXIT, are core serializing, we rely
# instead on write_cr3() performed by switch_mm() to provide core serialization
# after changing the current mm, and deal with the special case of kthread ->
# uthread (temporarily keeping current mm into active_mm) by issuing a
# sync_core_before_usermode() in that specific case.
#
    -----------------------
    |         arch |status|
    -----------------------
    |       alpha: | TODO |
    |         arc: | TODO |
    |         arm: | TODO |
    |       arm64: |  ok  |
    |    blackfin: | TODO |
    |         c6x: | TODO |
    |        cris: | TODO |
    |         frv: | TODO |
    |       h8300: | TODO |
    |     hexagon: | TODO |
    |        ia64: | TODO |
    |        m32r: | TODO |
    |        m68k: | TODO |
    |  microblaze: | TODO |
    |        mips: | TODO |
    |       nios2: | TODO |
    |    openrisc: | TODO |
    |      parisc: | TODO |
    |     powerpc: | TODO |
    |        s390: | TODO |
    |       score: | TODO |
    |          sh: | TODO |
    |       sparc: | TODO |
    |        tile: | TODO |
    |          um: | TODO |
    |   unicore32: | TODO |
    |         x86: |  ok  |
    |      xtensa: | TODO |
    -----------------------