+u32 (*ipi_read_clear)(int cpu);
+void (*ipi_write_action)(int cpu, u32 action);
+
+static u32 csr_ipi_read_clear(int cpu)
+{
+ u32 action;
+
+ /* Load the ipi register to figure out what we're supposed to do */
+ action = csr_readl(LOONGSON_CSR_IPI_STATUS);
+ /* Clear the ipi register to clear the interrupt */
+ csr_writel(action, LOONGSON_CSR_IPI_CLEAR);
+
+ return action;
+}
+
+static void csr_ipi_write_action(int cpu, u32 action)
+{
+ unsigned int irq = 0;
+
+ while ((irq = ffs(action))) {
+ uint32_t val = CSR_IPI_SEND_BLOCK;
+ val |= (irq - 1);
+ val |= (cpu << CSR_IPI_SEND_CPU_SHIFT);
+ csr_writel(val, LOONGSON_CSR_IPI_SEND);
+ action &= ~BIT(irq - 1);
+ }
+}
+
+static u32 legacy_ipi_read_clear(int cpu)
+{
+ u32 action;
+
+ /* Load the ipi register to figure out what we're supposed to do */
+ action = loongson3_ipi_read32(ipi_status0_regs[cpu_logical_map(cpu)]);
+ /* Clear the ipi register to clear the interrupt */
+ loongson3_ipi_write32(action, ipi_clear0_regs[cpu_logical_map(cpu)]);
+
+ return action;
+}
+
+static void legacy_ipi_write_action(int cpu, u32 action)
+{
+ loongson3_ipi_write32((u32)action, ipi_set0_regs[cpu]);
+}
+
+static void csr_ipi_probe(void)
+{
+ if (cpu_has_csr() && csr_readl(LOONGSON_CSR_FEATURES) & LOONGSON_CSRF_IPI) {
+ ipi_read_clear = csr_ipi_read_clear;
+ ipi_write_action = csr_ipi_write_action;
+ } else {
+ ipi_read_clear = legacy_ipi_read_clear;
+ ipi_write_action = legacy_ipi_write_action;
+ }
+}
+