RISC-V: Add mechanism to provide custom IPI operations

We add mechanism to set custom IPI operations so that CLINT driver
from drivers directory can provide custom IPI operations.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Tested-by: Emil Renner Berhing <kernel@esmil.dk>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

1 files changed, 24 insertions, 19 deletions

diff --git a/arch/riscv/kernel/smp.c b/arch/riscv/kernel/smp.c
index 554b0fb47060..cf9acb43604c 100644
--- a/arch/riscv/kernel/smp.c
+++ b/arch/riscv/kernel/smp.c
@@ -86,9 +86,25 @@ static void ipi_stop(void)
 		wait_for_interrupt();
 }
 
+static struct riscv_ipi_ops *ipi_ops;
+
+void riscv_set_ipi_ops(struct riscv_ipi_ops *ops)
+{
+	ipi_ops = ops;
+}
+EXPORT_SYMBOL_GPL(riscv_set_ipi_ops);
+
+void riscv_clear_ipi(void)
+{
+	if (ipi_ops && ipi_ops->ipi_clear)
+		ipi_ops->ipi_clear();
+
+	csr_clear(CSR_IP, IE_SIE);
+}
+EXPORT_SYMBOL_GPL(riscv_clear_ipi);
+
 static void send_ipi_mask(const struct cpumask *mask, enum ipi_message_type op)
 {
-	struct cpumask hartid_mask;
 	int cpu;
 
 	smp_mb__before_atomic();
@@ -96,33 +112,22 @@ static void send_ipi_mask(const struct cpumask *mask, enum ipi_message_type op)
 		set_bit(op, &ipi_data[cpu].bits);
 	smp_mb__after_atomic();
 
-	riscv_cpuid_to_hartid_mask(mask, &hartid_mask);
-	if (IS_ENABLED(CONFIG_RISCV_SBI))
-		sbi_send_ipi(cpumask_bits(&hartid_mask));
+	if (ipi_ops && ipi_ops->ipi_inject)
+		ipi_ops->ipi_inject(mask);
 	else
-		clint_send_ipi_mask(mask);
+		pr_warn("SMP: IPI inject method not available\n");
 }
 
 static void send_ipi_single(int cpu, enum ipi_message_type op)
 {
-	int hartid = cpuid_to_hartid_map(cpu);
-
 	smp_mb__before_atomic();
 	set_bit(op, &ipi_data[cpu].bits);
 	smp_mb__after_atomic();
 
-	if (IS_ENABLED(CONFIG_RISCV_SBI))
-		sbi_send_ipi(cpumask_bits(cpumask_of(hartid)));
-	else
-		clint_send_ipi_single(hartid);
-}
-
-static inline void clear_ipi(void)
-{
-	if (IS_ENABLED(CONFIG_RISCV_SBI))
-		csr_clear(CSR_IP, IE_SIE);
+	if (ipi_ops && ipi_ops->ipi_inject)
+		ipi_ops->ipi_inject(cpumask_of(cpu));
 	else
-		clint_clear_ipi(cpuid_to_hartid_map(smp_processor_id()));
+		pr_warn("SMP: IPI inject method not available\n");
 }
 
 #ifdef CONFIG_IRQ_WORK
@@ -140,7 +145,7 @@ void handle_IPI(struct pt_regs *regs)
 
 	irq_enter();
 
-	clear_ipi();
+	riscv_clear_ipi();
 
 	while (true) {
 		unsigned long ops;