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-rw-r--r--arch/riscv/include/asm/barrier.h10
-rw-r--r--arch/riscv/include/asm/thread_info.h4
2 files changed, 13 insertions, 1 deletions
diff --git a/arch/riscv/include/asm/barrier.h b/arch/riscv/include/asm/barrier.h
index 3f1737f301cc..d0e24aaa2aa0 100644
--- a/arch/riscv/include/asm/barrier.h
+++ b/arch/riscv/include/asm/barrier.h
@@ -58,8 +58,16 @@ do { \
* The AQ/RL pair provides a RCpc critical section, but there's not really any
* way we can take advantage of that here because the ordering is only enforced
* on that one lock. Thus, we're just doing a full fence.
+ *
+ * Since we allow writeX to be called from preemptive regions we need at least
+ * an "o" in the predecessor set to ensure device writes are visible before the
+ * task is marked as available for scheduling on a new hart. While I don't see
+ * any concrete reason we need a full IO fence, it seems safer to just upgrade
+ * this in order to avoid any IO crossing a scheduling boundary. In both
+ * instances the scheduler pairs this with an mb(), so nothing is necessary on
+ * the new hart.
*/
-#define smp_mb__after_spinlock() RISCV_FENCE(rw,rw)
+#define smp_mb__after_spinlock() RISCV_FENCE(iorw,iorw)
#include <asm-generic/barrier.h>
diff --git a/arch/riscv/include/asm/thread_info.h b/arch/riscv/include/asm/thread_info.h
index 1dd12a0cbb2b..464a2bbc97ea 100644
--- a/arch/riscv/include/asm/thread_info.h
+++ b/arch/riscv/include/asm/thread_info.h
@@ -12,7 +12,11 @@
#include <linux/const.h>
/* thread information allocation */
+#ifdef CONFIG_64BIT
+#define THREAD_SIZE_ORDER (2)
+#else
#define THREAD_SIZE_ORDER (1)
+#endif
#define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER)
#ifndef __ASSEMBLY__