[PATCH 04/20] riscv: optimize send_ipi_single

[Christoph Hellwig]

Don't go through send_ipi_mask, but just set the op bit an then pass a
simple generate hartid mask directly to sbi_send_ipi.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Atish Patra <atish.patra@xxxxxxx>
---
 arch/riscv/kernel/smp.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/arch/riscv/kernel/smp.c b/arch/riscv/kernel/smp.c
index 2e21669aa068..a3715d621f60 100644
--- a/arch/riscv/kernel/smp.c
+++ b/arch/riscv/kernel/smp.c
@@ -94,7 +94,13 @@ static void send_ipi_mask(const struct cpumask *mask, enum ipi_message_type op)
 
 static void send_ipi_single(int cpu, enum ipi_message_type op)
 {
-	send_ipi_mask(cpumask_of(cpu), op);
+	int hartid = cpuid_to_hartid_map(cpu);
+
+	smp_mb__before_atomic();
+	set_bit(op, &ipi_data[cpu].bits);
+	smp_mb__after_atomic();
+
+	sbi_send_ipi(cpumask_bits(cpumask_of(hartid)));
 }
 
 static inline void clear_ipi(void)
-- 
2.20.1