kernel: smp_cpu_rendezvous(): Use counter instead of bitmap

headers/private/kernel/smp.h

@@ -47,7 +47,7 @@ status_t smp_per_cpu_init(struct kernel_args *args, int32 cpu);
 status_t smp_init_post_generic_syscalls(void);
 bool smp_trap_non_boot_cpus(int32 cpu, uint32* rendezVous);
 void smp_wake_up_non_boot_cpus(void);
-void smp_cpu_rendezvous(uint32 *var, int current_cpu);
+void smp_cpu_rendezvous(uint32 *var);
 void smp_send_ici(int32 targetCPU, int32 message, addr_t data, addr_t data2, addr_t data3,
 		void *data_ptr, uint32 flags);
 void smp_send_multicast_ici(cpu_mask_t cpuMask, int32 message, addr_t data,

src/system/kernel/arch/x86/arch_cpu.cpp

@@ -189,7 +189,7 @@ set_mtrr(void* _parameter, int cpu)
 		= (struct set_mtrr_parameter*)_parameter;
 
 	// wait until all CPUs have arrived here
-	smp_cpu_rendezvous(&sCpuRendezvous, cpu);
+	smp_cpu_rendezvous(&sCpuRendezvous);
 
 	// One CPU has to reset sCpuRendezvous3 -- it is needed to prevent the CPU
 	// that initiated the call_all_cpus() from doing that again and clearing
@@ -206,8 +206,8 @@ set_mtrr(void* _parameter, int cpu)
 	enable_caches();
 
 	// wait until all CPUs have arrived here
-	smp_cpu_rendezvous(&sCpuRendezvous2, cpu);
-	smp_cpu_rendezvous(&sCpuRendezvous3, cpu);
+	smp_cpu_rendezvous(&sCpuRendezvous2);
+	smp_cpu_rendezvous(&sCpuRendezvous3);
 }
 
 
@@ -217,7 +217,7 @@ set_mtrrs(void* _parameter, int cpu)
 	set_mtrrs_parameter* parameter = (set_mtrrs_parameter*)_parameter;
 
 	// wait until all CPUs have arrived here
-	smp_cpu_rendezvous(&sCpuRendezvous, cpu);
+	smp_cpu_rendezvous(&sCpuRendezvous);
 
 	// One CPU has to reset sCpuRendezvous3 -- it is needed to prevent the CPU
 	// that initiated the call_all_cpus() from doing that again and clearing
@@ -234,8 +234,8 @@ set_mtrrs(void* _parameter, int cpu)
 	enable_caches();
 
 	// wait until all CPUs have arrived here
-	smp_cpu_rendezvous(&sCpuRendezvous2, cpu);
-	smp_cpu_rendezvous(&sCpuRendezvous3, cpu);
+	smp_cpu_rendezvous(&sCpuRendezvous2);
+	smp_cpu_rendezvous(&sCpuRendezvous3);
 }
 
 
@@ -243,7 +243,7 @@ static void
 init_mtrrs(void* _unused, int cpu)
 {
 	// wait until all CPUs have arrived here
-	smp_cpu_rendezvous(&sCpuRendezvous, cpu);
+	smp_cpu_rendezvous(&sCpuRendezvous);
 
 	// One CPU has to reset sCpuRendezvous3 -- it is needed to prevent the CPU
 	// that initiated the call_all_cpus() from doing that again and clearing
@@ -259,8 +259,8 @@ init_mtrrs(void* _unused, int cpu)
 	enable_caches();
 
 	// wait until all CPUs have arrived here
-	smp_cpu_rendezvous(&sCpuRendezvous2, cpu);
-	smp_cpu_rendezvous(&sCpuRendezvous3, cpu);
+	smp_cpu_rendezvous(&sCpuRendezvous2);
+	smp_cpu_rendezvous(&sCpuRendezvous3);
 }
 
 

src/system/kernel/main.cpp

@@ -100,13 +100,13 @@ _start(kernel_args *bootKernelArgs, int currentCPU)
 	smp_set_num_cpus(bootKernelArgs->num_cpus);
 
 	// wait for all the cpus to get here
-	smp_cpu_rendezvous(&sCpuRendezvous, currentCPU);
+	smp_cpu_rendezvous(&sCpuRendezvous);
 
 	// the passed in kernel args are in a non-allocated range of memory
 	if (currentCPU == 0)
 		memcpy(&sKernelArgs, bootKernelArgs, sizeof(kernel_args));
 
-	smp_cpu_rendezvous(&sCpuRendezvous2, currentCPU);
+	smp_cpu_rendezvous(&sCpuRendezvous2);
 
 	// do any pre-booting cpu config
 	cpu_preboot_init_percpu(&sKernelArgs, currentCPU);
@@ -221,13 +221,13 @@ _start(kernel_args *bootKernelArgs, int currentCPU)
 		TRACE("waking up AP cpus\n");
 		sCpuRendezvous = sCpuRendezvous2 = 0;
 		smp_wake_up_non_boot_cpus();
-		smp_cpu_rendezvous(&sCpuRendezvous, 0); // wait until they're booted
+		smp_cpu_rendezvous(&sCpuRendezvous); // wait until they're booted
 
 		// exit the kernel startup phase (mutexes, etc work from now on out)
 		TRACE("exiting kernel startup\n");
 		gKernelStartup = false;
 
-		smp_cpu_rendezvous(&sCpuRendezvous2, 0);
+		smp_cpu_rendezvous(&sCpuRendezvous2);
 			// release the AP cpus to go enter the scheduler
 
 		TRACE("starting scheduler on cpu 0 and enabling interrupts\n");
@@ -244,8 +244,8 @@ _start(kernel_args *bootKernelArgs, int currentCPU)
 		smp_per_cpu_init(&sKernelArgs, currentCPU);
 
 		// wait for all other AP cpus to get to this point
-		smp_cpu_rendezvous(&sCpuRendezvous, currentCPU);
-		smp_cpu_rendezvous(&sCpuRendezvous2, currentCPU);
+		smp_cpu_rendezvous(&sCpuRendezvous);
+		smp_cpu_rendezvous(&sCpuRendezvous2);
 
 		// welcome to the machine
 		scheduler_start();

src/system/kernel/smp.cpp

@@ -1313,11 +1313,11 @@ bool
 smp_trap_non_boot_cpus(int32 cpu, uint32* rendezVous)
 {
 	if (cpu == 0) {
-		smp_cpu_rendezvous(rendezVous, cpu);
+		smp_cpu_rendezvous(rendezVous);
 		return true;
 	}
 
-	smp_cpu_rendezvous(rendezVous, cpu);
+	smp_cpu_rendezvous(rendezVous);
 
 	while (atomic_get(&sBootCPUSpin) == 0) {
 		if ((atomic_get(&sEarlyCPUCall) & (1 << cpu)) != 0)
@@ -1353,13 +1353,12 @@ smp_wake_up_non_boot_cpus()
 	ensured via another rendez-vous) the variable can be reset.
 */
 void
-smp_cpu_rendezvous(uint32* var, int current_cpu)
+smp_cpu_rendezvous(uint32* var)
 {
-	atomic_or((int32*)var, 1 << current_cpu);
+	atomic_add((int32*)var, 1);
 
-	uint32 allReady = ((uint32)1 << sNumCPUs) - 1;
-	while ((uint32)atomic_get((int32*)var) != allReady)
-		cpu_wait((int32*)var, allReady);
+	while ((uint32)atomic_get((int32*)var) < sNumCPUs)
+		cpu_wait((int32*)var, sNumCPUs);
 }