From 435b8dd2528f597e28b4ab99f57f7f81ae52a92b Mon Sep 17 00:00:00 2001
From: Alexander Boettcher <alexander.boettcher@genode-labs.com>
Date: Wed, 24 Jul 2013 09:48:54 +0200
Subject: [PATCH] foc: determine number of CPUs

Issue #814
Fixes #578
---
 base-foc/src/core/include/platform.h |  1 +
 base-foc/src/core/platform.cc        | 24 ++++++++++++++++++++++++
 2 files changed, 25 insertions(+)

diff --git a/base-foc/src/core/include/platform.h b/base-foc/src/core/include/platform.h
index 9b9eab64a..b62ecf4d7 100644
--- a/base-foc/src/core/include/platform.h
+++ b/base-foc/src/core/include/platform.h
@@ -159,6 +159,7 @@ namespace Genode {
 			addr_t            vm_start() const { return _vm_start;       }
 			size_t            vm_size()  const { return _vm_size;        }
 			Rom_fs           *rom_fs()         { return &_rom_fs;        }
+			unsigned          num_cpus() const;
 
 			void wait_for_exit();
 	};
diff --git a/base-foc/src/core/platform.cc b/base-foc/src/core/platform.cc
index b8120ffeb..1522f5660 100644
--- a/base-foc/src/core/platform.cc
+++ b/base-foc/src/core/platform.cc
@@ -35,6 +35,7 @@ namespace Fiasco {
 #include <l4/sys/thread.h>
 #include <l4/sys/types.h>
 #include <l4/sys/utcb.h>
+#include <l4/sys/scheduler.h>
 
 static l4_kernel_info_t *kip;
 }
@@ -511,4 +512,27 @@ void Platform::wait_for_exit()
 }
 
 
+unsigned Platform::num_cpus() const {
+
+	using namespace Genode;
+	using namespace Fiasco;
+	
+	l4_sched_cpu_set_t cpus = l4_sched_cpu_set(0, 0, 1);
+	l4_umword_t cpus_max;
+	l4_msgtag_t res = l4_scheduler_info(L4_BASE_SCHEDULER_CAP, &cpus_max,
+	                                    &cpus);
+	if (l4_error(res)) {
+		PERR("could not detect number of CPUs - assuming 1 CPU");
+		return 1;
+	}
+
+	unsigned cpus_online = 0;
+	for (unsigned i = 0; i < sizeof(cpus.map) * 8; i++)
+		if ((cpus.map >> i) & 0x1)
+			cpus_online ++;
+		
+	return cpus_online;
+}
+
+
 void Core_parent::exit(int exit_value) { }