Allow a thread to wait some specified amount of time. Can
specify in cycles, usecs, and msecs.
Signed-off-by: Andrew Jones <drjones@xxxxxxxxxx>
---
v8: rewrote basing on new sysreg framework. Also decided delay
functions warrant their own files (delay.[ch])
---
arm/Makefile.common | 1 +
lib/arm/asm/delay.h | 14 ++++++++++++++
lib/arm/asm/processor.h | 15 +++++++++++++++
lib/arm64/asm/delay.h | 1 +
lib/arm64/asm/processor.h | 12 ++++++++++++
lib/arm/delay.c | 29 +++++++++++++++++++++++++++++
6 files changed, 72 insertions(+)
create mode 100644 lib/arm/asm/delay.h
create mode 100644 lib/arm64/asm/delay.h
create mode 100644 lib/arm/delay.c
diff --git a/arm/Makefile.common b/arm/Makefile.common
index b2c0fc8a2fdc..89fe3f69eb44 100644
--- a/arm/Makefile.common
+++ b/arm/Makefile.common
@@ -48,6 +48,7 @@ cflatobjs += lib/arm/mmu.o
cflatobjs += lib/arm/bitops.o
cflatobjs += lib/arm/psci.o
cflatobjs += lib/arm/smp.o
+cflatobjs += lib/arm/delay.o
libeabi = lib/arm/libeabi.a
eabiobjs = lib/arm/eabi_compat.o
diff --git a/lib/arm/asm/delay.h b/lib/arm/asm/delay.h
new file mode 100644
index 000000000000..2436b28c77ae
--- /dev/null
+++ b/lib/arm/asm/delay.h
@@ -0,0 +1,14 @@
+#ifndef _ASMARM_DELAY_H_
+#define _ASMARM_DELAY_H_
+/*
+ * Copyright (C) 2016, Red Hat Inc, Andrew Jones <drjones@xxxxxxxxxx>
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2.
+ */
+#include <libcflat.h>
+
+extern void delay(u64 cycles);
+extern void udelay(unsigned long usecs);
+extern void mdelay(unsigned long msecs);
+
+#endif /* _ASMARM_DELAY_H_ */
diff --git a/lib/arm/asm/processor.h b/lib/arm/asm/processor.h
index 6b0d36b87817..857bdd96a3cc 100644
--- a/lib/arm/asm/processor.h
+++ b/lib/arm/asm/processor.h
@@ -7,6 +7,7 @@
*/
#include <asm/ptrace.h>
#include <asm/sysreg.h>
+#include <asm/barrier.h>
enum vector {
EXCPTN_RST,
@@ -51,4 +52,18 @@ extern int mpidr_to_cpu(uint64_t mpidr);
extern void start_usr(void (*func)(void *arg), void *arg, unsigned long sp_usr);
extern bool is_user(void);
+#define CNTVCT __ACCESS_CP15_64(1, c14)
+#define CNTFRQ __ACCESS_CP15(c14, 0, c0, 0)
+
+static inline u64 get_cntvct(void)
+{
+ isb();
+ return read_sysreg(CNTVCT);
+}
+
+static inline u32 get_cntfrq(void)
+{
+ return read_sysreg(CNTFRQ);
+}
+
#endif /* _ASMARM_PROCESSOR_H_ */
diff --git a/lib/arm64/asm/delay.h b/lib/arm64/asm/delay.h
new file mode 100644
index 000000000000..288e4b3fe610
--- /dev/null
+++ b/lib/arm64/asm/delay.h
@@ -0,0 +1 @@
+#include "../../arm/asm/delay.h"
diff --git a/lib/arm64/asm/processor.h b/lib/arm64/asm/processor.h
index 48abf2c9e358..0898d89f9761 100644
--- a/lib/arm64/asm/processor.h
+++ b/lib/arm64/asm/processor.h
@@ -20,6 +20,7 @@
#include <asm/ptrace.h>
#include <asm/esr.h>
#include <asm/sysreg.h>
+#include <asm/barrier.h>
enum vector {
EL1T_SYNC,
@@ -83,5 +84,16 @@ extern int mpidr_to_cpu(uint64_t mpidr);
extern void start_usr(void (*func)(void *arg), void *arg, unsigned long sp_usr);
extern bool is_user(void);
+static inline u64 get_cntvct(void)
+{
+ isb();
+ return read_sysreg(cntvct_el0);
+}
+
+static inline u32 get_cntfrq(void)
+{
+ return read_sysreg(cntfrq_el0);
+}
+
#endif /* !__ASSEMBLY__ */
#endif /* _ASMARM64_PROCESSOR_H_ */
diff --git a/lib/arm/delay.c b/lib/arm/delay.c
new file mode 100644
index 000000000000..fa65e2dc9e35
--- /dev/null
+++ b/lib/arm/delay.c
@@ -0,0 +1,29 @@
+/*
+ * Delay loops
+ *
+ * Copyright (C) 2016, Red Hat Inc, Andrew Jones <drjones@xxxxxxxxxx>
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2.
+ */
+#include <libcflat.h>
+#include <asm/processor.h>
+#include <asm/barrier.h>
+
+void delay(u64 cycles)
+{
+ u64 start = get_cntvct();
+
+ while ((get_cntvct() - start) < cycles)
+ cpu_relax();
+}
+
+void udelay(unsigned long usec)
+{
+ delay((u64)usec * get_cntfrq() / 1000000);
+}
+
+void mdelay(unsigned long msecs)
+{
+ while (msecs--)
+ udelay(1000);
+}
--
2.9.3
--
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