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authorAndrea Parri <parri.andrea@gmail.com>2024-01-31 15:49:35 +0100
committerPalmer Dabbelt <palmer@rivosinc.com>2024-02-15 08:04:13 -0800
commit4ff4c745a16c4c151a71863420811e7f406c3ec2 (patch)
treefcda33acb75221cff1faee8582ab99e6ee96adbf
parenta14d11a0f5f4105e0df96811dfa81dc5f79fecba (diff)
locking: Introduce prepare_sync_core_cmd()
Introduce an architecture function that architectures can use to set up ("prepare") SYNC_CORE commands. The function will be used by RISC-V to update its "deferred icache- flush" data structures (icache_stale_mask). Architectures defining prepare_sync_core_cmd() static inline need to select ARCH_HAS_PREPARE_SYNC_CORE_CMD. Suggested-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Andrea Parri <parri.andrea@gmail.com> Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/r/20240131144936.29190-4-parri.andrea@gmail.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
-rw-r--r--include/linux/sync_core.h16
-rw-r--r--init/Kconfig3
-rw-r--r--kernel/sched/membarrier.c1
3 files changed, 19 insertions, 1 deletions
diff --git a/include/linux/sync_core.h b/include/linux/sync_core.h
index 013da4b8b327..67bb9794b875 100644
--- a/include/linux/sync_core.h
+++ b/include/linux/sync_core.h
@@ -17,5 +17,19 @@ static inline void sync_core_before_usermode(void)
}
#endif
-#endif /* _LINUX_SYNC_CORE_H */
+#ifdef CONFIG_ARCH_HAS_PREPARE_SYNC_CORE_CMD
+#include <asm/sync_core.h>
+#else
+/*
+ * This is a dummy prepare_sync_core_cmd() implementation that can be used on
+ * all architectures which provide unconditional core serializing instructions
+ * in switch_mm().
+ * If your architecture doesn't provide such core serializing instructions in
+ * switch_mm(), you may need to write your own functions.
+ */
+static inline void prepare_sync_core_cmd(struct mm_struct *mm)
+{
+}
+#endif
+#endif /* _LINUX_SYNC_CORE_H */
diff --git a/init/Kconfig b/init/Kconfig
index 8df18f3a9748..c3994b92333d 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1970,6 +1970,9 @@ source "kernel/Kconfig.locks"
config ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
bool
+config ARCH_HAS_PREPARE_SYNC_CORE_CMD
+ bool
+
config ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
bool
diff --git a/kernel/sched/membarrier.c b/kernel/sched/membarrier.c
index f3d91628d6b8..6d1f31b3a967 100644
--- a/kernel/sched/membarrier.c
+++ b/kernel/sched/membarrier.c
@@ -320,6 +320,7 @@ static int membarrier_private_expedited(int flags, int cpu_id)
MEMBARRIER_STATE_PRIVATE_EXPEDITED_SYNC_CORE_READY))
return -EPERM;
ipi_func = ipi_sync_core;
+ prepare_sync_core_cmd(mm);
} else if (flags == MEMBARRIER_FLAG_RSEQ) {
if (!IS_ENABLED(CONFIG_RSEQ))
return -EINVAL;