[RFC PATCH v1 2/4] riscv: mm: Introduce percpu tlb flush queue

[Xu Lu]

The percpu tlb flush queue is used to buffer the tlb flush tasks that
each cpu needs to process.

Signed-off-by: Xu Lu <luxu.kernel at bytedance.com>
---
 arch/riscv/mm/tlbflush.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/arch/riscv/mm/tlbflush.c b/arch/riscv/mm/tlbflush.c
index 8404530ec00f9..aa8f1304ae5c4 100644
--- a/arch/riscv/mm/tlbflush.c
+++ b/arch/riscv/mm/tlbflush.c
@@ -103,6 +103,18 @@ struct flush_tlb_range_data {
 	unsigned long stride;
 };
 
+#define TLB_FLUSH_QUEUE_SIZE					16
+struct tlb_flush_queue {
+	struct flush_tlb_range_data tasks[TLB_FLUSH_QUEUE_SIZE];
+	raw_spinlock_t lock;
+	unsigned int len;
+};
+
+DEFINE_PER_CPU(struct tlb_flush_queue, tlb_flush_queue) = {
+	.lock = __RAW_SPIN_LOCK_UNLOCKED(tlb_flush_queue.lock),
+	.len = 0,
+};
+
 static void __ipi_flush_tlb_range_asid(void *info)
 {
 	struct flush_tlb_range_data *d = info;
-- 
2.20.1