It would be nice if we had a generic sleep function which could be used
in unit tests, add one.
Add the variable tb_hz used to store the time base frequency which is read
from the device tree on setup.
Add functions msleep, usleep and sleep in processor.c to sleep for a given
number of milliseconds, microseconds and time base ticks respectively.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@xxxxxxxxx>
---
Change Log:
V2 -> V3:
- Add patch to series
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@xxxxxxxxx>
---
lib/powerpc/asm/processor.h | 19 +++++++++++++++++++
lib/powerpc/asm/setup.h | 2 ++
lib/powerpc/processor.c | 13 +++++++++++++
lib/powerpc/setup.c | 12 ++++++++++++
4 files changed, 46 insertions(+)
diff --git a/lib/powerpc/asm/processor.h b/lib/powerpc/asm/processor.h
index 09692bd..9554e08 100644
--- a/lib/powerpc/asm/processor.h
+++ b/lib/powerpc/asm/processor.h
@@ -1,11 +1,30 @@
#ifndef _ASMPOWERPC_PROCESSOR_H_
#define _ASMPOWERPC_PROCESSOR_H_
+#include <libcflat.h>
#include <asm/ptrace.h>
+#define cpu_relax() asm volatile ("" : : : "memory")
+
#ifndef __ASSEMBLY__
void handle_exception(int trap, void (*func)(struct pt_regs *, void *), void *);
void do_handle_exception(struct pt_regs *regs);
#endif /* __ASSEMBLY__ */
+static inline uint64_t get_tb(void)
+{
+ uint64_t tb;
+ asm volatile ("mfspr %[tb],268" : [tb] "=r" (tb));
+ return tb;
+}
+
+extern void delay(uint64_t cycles);
+extern void udelay(uint64_t us);
+
+static inline void mdelay(uint64_t ms)
+{
+ while (ms--)
+ udelay(1000);
+}
+
#endif /* _ASMPOWERPC_PROCESSOR_H_ */
diff --git a/lib/powerpc/asm/setup.h b/lib/powerpc/asm/setup.h
index b1e1e5a..23b4156 100644
--- a/lib/powerpc/asm/setup.h
+++ b/lib/powerpc/asm/setup.h
@@ -11,6 +11,8 @@
extern u32 cpus[NR_CPUS];
extern int nr_cpus;
+extern uint64_t tb_hz;
+
#define NR_MEM_REGIONS 8
#define MR_F_PRIMARY (1U << 0)
struct mem_region {
diff --git a/lib/powerpc/processor.c b/lib/powerpc/processor.c
index a78bc3c..c84bae5 100644
--- a/lib/powerpc/processor.c
+++ b/lib/powerpc/processor.c
@@ -5,6 +5,7 @@
#include <libcflat.h>
#include <asm/processor.h>
#include <asm/ptrace.h>
+#include <asm/setup.h>
static struct {
void (*func)(struct pt_regs *, void *data);
@@ -36,3 +37,15 @@ void do_handle_exception(struct pt_regs *regs)
printf("unhandled cpu exception 0x%lx\n", regs->trap);
abort();
}
+
+void delay(uint64_t cycles)
+{
+ uint64_t start = get_tb();
+ while((get_tb() - start) < cycles)
+ cpu_relax();
+}
+
+void udelay(uint64_t us)
+{
+ delay((us * tb_hz) / 1000000);
+}
diff --git a/lib/powerpc/setup.c b/lib/powerpc/setup.c
index e3d2afa..e7fa525 100644
--- a/lib/powerpc/setup.c
+++ b/lib/powerpc/setup.c
@@ -24,6 +24,7 @@ extern void setup_args_progname(const char *args);
u32 cpus[NR_CPUS] = { [0 ... NR_CPUS-1] = (~0U) };
int nr_cpus;
+uint64_t tb_hz;
struct mem_region mem_regions[NR_MEM_REGIONS];
phys_addr_t __physical_start, __physical_end;
@@ -51,6 +52,17 @@ static void cpu_set(int fdtnode, u32 regval, void *info)
}
cpus[cpu] = regval;
+ /* set timebase frequency */
+ if (!tb_hz) {
+ const struct fdt_property *prop;
+ u32 *data;
+ prop = fdt_get_property(dt_fdt(), fdtnode,
+ "timebase-frequency", NULL);
+ assert(prop != NULL);
+ data = (u32 *)prop->data;
+ tb_hz = fdt32_to_cpu(*data);
+ }
+
/* set exception stack address for this CPU (in SPGR0) */
asm volatile ("mtsprg0 %[addr]" ::
--
2.5.5
--
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