[bcm28xx][arm64][ipi] Fix IPI on non-GIC based BCM28xx

arch/arm64/mp.c

@@ -30,8 +30,11 @@
 
 #if WITH_DEV_INTERRUPT_ARM_GIC
 #include <dev/interrupt/arm_gic.h>
-//#else
-//#error need other implementation of interrupt controller that can ipi
+#elif PLATFORM_BCM28XX
+/* bcm28xx has a weird custom interrupt controller for MP */
+extern void bcm28xx_send_ipi(uint irq, uint cpu_mask);
+#else
+#error need other implementation of interrupt controller that can ipi
 #endif
 
 #define LOCAL_TRACE 0
@@ -51,6 +54,12 @@ status_t arch_mp_send_ipi(mp_cpu_mask_t target, mp_ipi_t ipi)
         LTRACEF("target 0x%x, gic_ipi %u\n", target, gic_ipi_num);
         arm_gic_sgi(gic_ipi_num, ARM_GIC_SGI_FLAG_NS, target);
     }
+#elif PLATFORM_BCM2835
+    /* filter out targets outside of the range of cpus we care about */
+    target &= ((1UL << SMP_MAX_CPUS) - 1);
+    if (target != 0) {
+        bcm28xx_send_ipi(ipi, target);
+    }
 #endif
 
     return NO_ERROR;