summaryrefslogtreecommitdiff
path: root/arch/arm/include/asm/percpu.h
diff options
context:
space:
mode:
authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /arch/arm/include/asm/percpu.h
Initial import
Diffstat (limited to 'arch/arm/include/asm/percpu.h')
-rw-r--r--arch/arm/include/asm/percpu.h52
1 files changed, 52 insertions, 0 deletions
diff --git a/arch/arm/include/asm/percpu.h b/arch/arm/include/asm/percpu.h
new file mode 100644
index 000000000..a89b4076c
--- /dev/null
+++ b/arch/arm/include/asm/percpu.h
@@ -0,0 +1,52 @@
+/*
+ * Copyright 2012 Calxeda, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+#ifndef _ASM_ARM_PERCPU_H_
+#define _ASM_ARM_PERCPU_H_
+
+/*
+ * Same as asm-generic/percpu.h, except that we store the per cpu offset
+ * in the TPIDRPRW. TPIDRPRW only exists on V6K and V7
+ */
+#if defined(CONFIG_SMP) && !defined(CONFIG_CPU_V6)
+static inline void set_my_cpu_offset(unsigned long off)
+{
+ /* Set TPIDRPRW */
+ asm volatile("mcr p15, 0, %0, c13, c0, 4" : : "r" (off) : "memory");
+}
+
+static inline unsigned long __my_cpu_offset(void)
+{
+ unsigned long off;
+
+ /*
+ * Read TPIDRPRW.
+ * We want to allow caching the value, so avoid using volatile and
+ * instead use a fake stack read to hazard against barrier().
+ */
+ asm("mrc p15, 0, %0, c13, c0, 4" : "=r" (off)
+ : "Q" (*(const unsigned long *)current_stack_pointer));
+
+ return off;
+}
+#define __my_cpu_offset __my_cpu_offset()
+#else
+#define set_my_cpu_offset(x) do {} while(0)
+
+#endif /* CONFIG_SMP */
+
+#include <asm-generic/percpu.h>
+
+#endif /* _ASM_ARM_PERCPU_H_ */