summaryrefslogtreecommitdiffstats
path: root/Documentation/features/sched
diff options
context:
space:
mode:
authorRob Herring (Arm) <robh@kernel.org>2026-08-31 14:43:51 -0500
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2026-09-13 18:17:31 -0700
commit55fc280e951ab2b39f3dcb640edc1b1eebc6d173 (patch)
treef0b5f37b42fc13b9908a31b657c646b024231cdd /Documentation/features/sched
downloadlinux-stable-55fc280e951ab2b39f3dcb640edc1b1eebc6d173.tar.gz
linux-stable-55fc280e951ab2b39f3dcb640edc1b1eebc6d173.zip
Input: tsc2007 - read "ti,poll-period" as u32grafted
The "ti,poll-period" property is documented as a normal uint32 cell. The driver used a u64 helper, which makes the helper type disagree with the schema even though the stored value is still small. Read "ti,poll-period" with the u32 helper matching the documented DT cell size. Assisted-by: Codex:gpt-5-5 Signed-off-by: Rob Herring (Arm) <robh@kernel.org> Link: https://patch.msgid.link/20260831194352.1185860-1-robh@kernel.org Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Diffstat (limited to 'Documentation/features/sched')
-rw-r--r--Documentation/features/sched/membarrier-sync-core/arch-support.txt69
-rw-r--r--Documentation/features/sched/numa-balancing/arch-support.txt30
2 files changed, 99 insertions, 0 deletions
diff --git a/Documentation/features/sched/membarrier-sync-core/arch-support.txt b/Documentation/features/sched/membarrier-sync-core/arch-support.txt
new file mode 100644
index 000000000..7425d2b99
--- /dev/null
+++ b/Documentation/features/sched/membarrier-sync-core/arch-support.txt
@@ -0,0 +1,69 @@
+#
+# Feature name: membarrier-sync-core
+# Kconfig: ARCH_HAS_MEMBARRIER_SYNC_CORE
+# description: arch supports core serializing membarrier
+#
+# Architecture requirements
+#
+# * arm/arm64/powerpc/s390
+#
+# Rely on implicit context synchronization as a result of exception return
+# when returning from IPI handler, and when returning to user-space.
+#
+# * riscv
+#
+# riscv uses xRET as return from interrupt and to return to user-space.
+#
+# Given that xRET is not core serializing, we rely on FENCE.I for providing
+# core serialization:
+#
+# - by calling sync_core_before_usermode() on return from interrupt (cf.
+# ipi_sync_core()),
+#
+# - via switch_mm() and sync_core_before_usermode() (respectively, for
+# uthread->uthread and kthread->uthread transitions) before returning
+# to user-space.
+#
+# The serialization in switch_mm() is activated by prepare_sync_core_cmd().
+#
+# * 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: | ok |
+ | arm64: | ok |
+ | csky: | TODO |
+ | hexagon: | TODO |
+ | loongarch: | TODO |
+ | m68k: | TODO |
+ | microblaze: | TODO |
+ | mips: | TODO |
+ | nios2: | TODO |
+ | openrisc: | TODO |
+ | parisc: | TODO |
+ | powerpc: | ok |
+ | riscv: | ok |
+ | s390: | ok |
+ | sh: | TODO |
+ | sparc: | TODO |
+ | um: | TODO |
+ | x86: | ok |
+ | xtensa: | TODO |
+ -----------------------
diff --git a/Documentation/features/sched/numa-balancing/arch-support.txt b/Documentation/features/sched/numa-balancing/arch-support.txt
new file mode 100644
index 000000000..984601c7c
--- /dev/null
+++ b/Documentation/features/sched/numa-balancing/arch-support.txt
@@ -0,0 +1,30 @@
+#
+# Feature name: numa-balancing
+# Kconfig: ARCH_SUPPORTS_NUMA_BALANCING
+# description: arch supports NUMA balancing
+#
+ -----------------------
+ | arch |status|
+ -----------------------
+ | alpha: | TODO |
+ | arc: | .. |
+ | arm: | .. |
+ | arm64: | ok |
+ | csky: | .. |
+ | hexagon: | .. |
+ | loongarch: | ok |
+ | m68k: | .. |
+ | microblaze: | .. |
+ | mips: | TODO |
+ | nios2: | .. |
+ | openrisc: | .. |
+ | parisc: | .. |
+ | powerpc: | ok |
+ | riscv: | ok |
+ | s390: | ok |
+ | sh: | .. |
+ | sparc: | TODO |
+ | um: | .. |
+ | x86: | ok |
+ | xtensa: | .. |
+ -----------------------