[U-Boot] [PATCH 0/5] Introduce basic headers for time, typecheck, iopoll

[U-Boot] [PATCH 0/5] Introduce basic headers for time, typecheck, iopoll

[Masahiro Yamada]

Masahiro Yamada (5):
  delay: collect {m,n,u}delay declarations to include/linux/delay.h
  time: move timer APIs to include/time.h
  typecheck: import include/linux/typecheck.h from Linux 4.9
  time: import time_after, time_before and friends from Linux
  iopoll: import include/linux/iopoll.h from Linux 4.9

 include/common.h          | 14 ++--------
 include/linux/compat.h    |  2 --
 include/linux/delay.h     | 24 +++++++++++++++++
 include/linux/iopoll.h    | 68 +++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/typecheck.h | 24 +++++++++++++++++
 include/time.h            | 57 +++++++++++++++++++++++++++++++++++++++
 lib/time.c                |  6 -----
 7 files changed, 175 insertions(+), 20 deletions(-)
 create mode 100644 include/linux/delay.h
 create mode 100644 include/linux/iopoll.h
 create mode 100644 include/linux/typecheck.h
 create mode 100644 include/time.h

-- 
2.7.4

[U-Boot] [PATCH 1/5] delay: collect {m, n, u}delay declarations to include/linux/delay.h

[Masahiro Yamada]

Currently, mdelay() and udelay() are declared in include/common.h,
while ndelay() in include/linux/compat.h.  It would be nice to
collect them into include/linux/delay.h like Linux.

While we are here, fix the ndelay() implementation; I used the
DIV_ROUND_UP() instead of (x)/1000 because we must wait *longer*
than the given period of time.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

 include/common.h       |  6 +-----
 include/linux/compat.h |  2 --
 include/linux/delay.h  | 24 ++++++++++++++++++++++++
 lib/time.c             |  6 ------
 4 files changed, 25 insertions(+), 13 deletions(-)
 create mode 100644 include/linux/delay.h

diff --git a/include/common.h b/include/common.h
index a8d833b..682205d 100644
--- a/include/common.h
+++ b/include/common.h
@@ -19,6 +19,7 @@ typedef volatile unsigned char	vu_char;
 #include <errno.h>
 #include <asm-offsets.h>
 #include <linux/bitops.h>
+#include <linux/delay.h>
 #include <linux/types.h>
 #include <linux/string.h>
 #include <linux/stringify.h>
@@ -776,7 +777,6 @@ uint64_t get_ticks(void);
 void	wait_ticks    (unsigned long);
 
 /* arch/$(ARCH)/lib/time.c */
-void	__udelay      (unsigned long);
 ulong	usec2ticks    (unsigned long usec);
 ulong	ticks2usec    (unsigned long ticks);
 int	init_timebase (void);
@@ -833,10 +833,6 @@ void qsort(void *base, size_t nmemb, size_t size,
 	   int(*compar)(const void *, const void *));
 int strcmp_compar(const void *, const void *);
 
-/* lib/time.c */
-void	udelay        (unsigned long);
-void mdelay(unsigned long);
-
 /* lib/uuid.c */
 #include <uuid.h>
 
diff --git a/include/linux/compat.h b/include/linux/compat.h
index 533983f..a43e4d6 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -15,8 +15,6 @@ struct p_current{
 
 extern struct p_current *current;
 
-#define ndelay(x)	udelay((x) < 1000 ? 1 : (x)/1000)
-
 #define dev_dbg(dev, fmt, args...)		\
 	debug(fmt, ##args)
 #define dev_vdbg(dev, fmt, args...)		\
diff --git a/include/linux/delay.h b/include/linux/delay.h
new file mode 100644
index 0000000..3dcd435
--- /dev/null
+++ b/include/linux/delay.h
@@ -0,0 +1,24 @@
+/*
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef _LINUX_DELAY_H
+#define _LINUX_DELAY_H
+
+#include <linux/kernel.h>
+
+void __udelay(unsigned long usec);
+void udelay(unsigned long usec);
+
+static inline void mdelay(unsigned long msec)
+{
+	while (msec--)
+		udelay(1000);
+}
+
+static inline void ndelay(unsigned long nsec)
+{
+	udelay(DIV_ROUND_UP(nsec, 1000));
+}
+
+#endif /* defined(_LINUX_DELAY_H) */
diff --git a/lib/time.c b/lib/time.c
index f37150f..3c49243 100644
--- a/lib/time.c
+++ b/lib/time.c
@@ -154,9 +154,3 @@ void udelay(unsigned long usec)
 		usec -= kv;
 	} while(usec);
 }
-
-void mdelay(unsigned long msec)
-{
-	while (msec--)
-		udelay(1000);
-}
-- 
2.7.4

[U-Boot] [PATCH 2/5] time: move timer APIs to include/time.h

[Masahiro Yamada]

The include/common.h is a collection of unrelated declarations,
macros, etc.

It is horrible to include such a cluttered header just for some
timer functions.  Split out timer functions into include/timer.h.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

 include/common.h |  8 +-------
 include/time.h   | 16 ++++++++++++++++
 2 files changed, 17 insertions(+), 7 deletions(-)
 create mode 100644 include/time.h

diff --git a/include/common.h b/include/common.h
index 682205d..08f581c 100644
--- a/include/common.h
+++ b/include/common.h
@@ -17,6 +17,7 @@ typedef volatile unsigned char	vu_char;
 
 #include <config.h>
 #include <errno.h>
+#include <time.h>
 #include <asm-offsets.h>
 #include <linux/bitops.h>
 #include <linux/delay.h>
@@ -577,12 +578,6 @@ void ddr_enable_ecc(unsigned int dram_size);
 #endif
 #endif
 
-/*
- * Return the current value of a monotonically increasing microsecond timer.
- * Granularity may be larger than 1us if hardware does not support this.
- */
-ulong timer_get_us(void);
-
 /* $(CPU)/cpu.c */
 static inline int cpumask_next(int cpu, unsigned int mask)
 {
@@ -721,7 +716,6 @@ void	external_interrupt (struct pt_regs *);
 void	irq_install_handler(int, interrupt_handler_t *, void *);
 void	irq_free_handler   (int);
 void	reset_timer	   (void);
-ulong	get_timer	   (ulong base);
 
 /* Return value of monotonic microsecond timer */
 unsigned long timer_get_us(void);
diff --git a/include/time.h b/include/time.h
new file mode 100644
index 0000000..5ed021f
--- /dev/null
+++ b/include/time.h
@@ -0,0 +1,16 @@
+/*
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef _TIME_H
+#define _TIME_H
+
+unsigned long get_timer(unsigned long base);
+
+/*
+ * Return the current value of a monotonically increasing microsecond timer.
+ * Granularity may be larger than 1us if hardware does not support this.
+ */
+unsigned long timer_get_us(void);
+
+#endif /* _TIME_H */
-- 
2.7.4

[U-Boot] [PATCH 3/5] typecheck: import include/linux/typecheck.h from Linux 4.9

[Masahiro Yamada]

Copied from Linux 4.9.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

 include/linux/typecheck.h | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)
 create mode 100644 include/linux/typecheck.h

diff --git a/include/linux/typecheck.h b/include/linux/typecheck.h
new file mode 100644
index 0000000..eb5b74a
--- /dev/null
+++ b/include/linux/typecheck.h
@@ -0,0 +1,24 @@
+#ifndef TYPECHECK_H_INCLUDED
+#define TYPECHECK_H_INCLUDED
+
+/*
+ * Check at compile time that something is of a particular type.
+ * Always evaluates to 1 so you may use it easily in comparisons.
+ */
+#define typecheck(type,x) \
+({	type __dummy; \
+	typeof(x) __dummy2; \
+	(void)(&__dummy == &__dummy2); \
+	1; \
+})
+
+/*
+ * Check at compile time that 'function' is a certain type, or is a pointer
+ * to that type (needs to use typedef for the function type.)
+ */
+#define typecheck_fn(type,function) \
+({	typeof(type) __tmp = function; \
+	(void)__tmp; \
+})
+
+#endif		/* TYPECHECK_H_INCLUDED */
-- 
2.7.4

[U-Boot] [PATCH 4/5] time: import time_after, time_before and friends from Linux

[Masahiro Yamada]

It is not safe to compare timer values directly.

On 32-bit systems, for example, timer_get_us() wraps around every
72 min. (2 ^ 32 / 1000000 =~ 4295 sec =~ 72 min).  Depending on
the get_ticks() implementation, it may wrap more frequently.
The 72 min might be possible on the use of U-Boot.

Let's borrow time_after, time_before, and friends to solve the
wrap-around problem.

These macros were copied from include/linux/jiffies.h of Linux 4.9.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

 include/time.h | 41 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)

diff --git a/include/time.h b/include/time.h
index 5ed021f..5746ad9 100644
--- a/include/time.h
+++ b/include/time.h
@@ -5,6 +5,8 @@
 #ifndef _TIME_H
 #define _TIME_H
 
+#include <linux/typecheck.h>
+
 unsigned long get_timer(unsigned long base);
 
 /*
@@ -13,4 +15,43 @@ unsigned long get_timer(unsigned long base);
  */
 unsigned long timer_get_us(void);
 
+/*
+ *	These inlines deal with timer wrapping correctly. You are
+ *	strongly encouraged to use them
+ *	1. Because people otherwise forget
+ *	2. Because if the timer wrap changes in future you won't have to
+ *	   alter your driver code.
+ *
+ * time_after(a,b) returns true if the time a is after time b.
+ *
+ * Do this with "<0" and ">=0" to only test the sign of the result. A
+ * good compiler would generate better code (and a really good compiler
+ * wouldn't care). Gcc is currently neither.
+ */
+#define time_after(a,b)		\
+	(typecheck(unsigned long, a) && \
+	 typecheck(unsigned long, b) && \
+	 ((long)((b) - (a)) < 0))
+#define time_before(a,b)	time_after(b,a)
+
+#define time_after_eq(a,b)	\
+	(typecheck(unsigned long, a) && \
+	 typecheck(unsigned long, b) && \
+	 ((long)((a) - (b)) >= 0))
+#define time_before_eq(a,b)	time_after_eq(b,a)
+
+/*
+ * Calculate whether a is in the range of [b, c].
+ */
+#define time_in_range(a,b,c) \
+	(time_after_eq(a,b) && \
+	 time_before_eq(a,c))
+
+/*
+ * Calculate whether a is in the range of [b, c).
+ */
+#define time_in_range_open(a,b,c) \
+	(time_after_eq(a,b) && \
+	 time_before(a,c))
+
 #endif /* _TIME_H */
-- 
2.7.4

[U-Boot] [PATCH 5/5] iopoll: import include/linux/iopoll.h from Linux 4.9

[Masahiro Yamada]

This was imported from Linux 4.9 and adjusted for U-Boot.

 - Replace the license block with SPDX
 - Drop all *_atomic variants, which make no sense for U-Boot
 - Remove the sleep_us argument, which makes no sense for U-Boot

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

 include/linux/iopoll.h | 68 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 68 insertions(+)
 create mode 100644 include/linux/iopoll.h

diff --git a/include/linux/iopoll.h b/include/linux/iopoll.h
new file mode 100644
index 0000000..31c55ae
--- /dev/null
+++ b/include/linux/iopoll.h
@@ -0,0 +1,68 @@
+/*
+ * Copyright (c) 2012-2014 The Linux Foundation. All rights reserved.
+ *
+ * SPDX-License-Identifier:	GPL-2.0
+ */
+
+#ifndef _LINUX_IOPOLL_H
+#define _LINUX_IOPOLL_H
+
+#include <linux/errno.h>
+#include <linux/io.h>
+#include <time.h>
+
+/**
+ * readx_poll_timeout - Periodically poll an address until a condition is met or a timeout occurs
+ * @op: accessor function (takes @addr as its only argument)
+ * @addr: Address to poll
+ * @val: Variable to read the value into
+ * @cond: Break condition (usually involving @val)
+ * @timeout_us: Timeout in us, 0 means never timeout
+ *
+ * Returns 0 on success and -ETIMEDOUT upon a timeout. In either
+ * case, the last read value at @addr is stored in @val.
+ *
+ * When available, you'll probably want to use one of the specialized
+ * macros defined below rather than this macro directly.
+ */
+#define readx_poll_timeout(op, addr, val, cond, timeout_us)	\
+({ \
+	unsigned long timeout = timer_get_us() + timeout_us; \
+	for (;;) { \
+		(val) = op(addr); \
+		if (cond) \
+			break; \
+		if (timeout_us && time_after(timer_get_us(), timeout)) { \
+			(val) = op(addr); \
+			break; \
+		} \
+	} \
+	(cond) ? 0 : -ETIMEDOUT; \
+})
+
+
+#define readb_poll_timeout(addr, val, cond, timeout_us) \
+	readx_poll_timeout(readb, addr, val, cond, timeout_us)
+
+#define readw_poll_timeout(addr, val, cond, timeout_us) \
+	readx_poll_timeout(readw, addr, val, cond, timeout_us)
+
+#define readl_poll_timeout(addr, val, cond, timeout_us) \
+	readx_poll_timeout(readl, addr, val, cond, timeout_us)
+
+#define readq_poll_timeout(addr, val, cond, timeout_us) \
+	readx_poll_timeout(readq, addr, val, cond, timeout_us)
+
+#define readb_relaxed_poll_timeout(addr, val, cond, timeout_us) \
+	readx_poll_timeout(readb_relaxed, addr, val, cond, timeout_us)
+
+#define readw_relaxed_poll_timeout(addr, val, cond, timeout_us) \
+	readx_poll_timeout(readw_relaxed, addr, val, cond, timeout_us)
+
+#define readl_relaxed_poll_timeout(addr, val, cond, timeout_us) \
+	readx_poll_timeout(readl_relaxed, addr, val, cond, timeout_us)
+
+#define readq_relaxed_poll_timeout(addr, val, cond, timeout_us) \
+	readx_poll_timeout(readq_relaxed, addr, val, cond, timeout_us)
+
+#endif /* _LINUX_IOPOLL_H */
-- 
2.7.4

[U-Boot] [PATCH 2/5] time: move timer APIs to include/time.h

[Simon Glass]

On 20 December 2016 at 19:53, Masahiro Yamada
<yamada.masahiro@socionext.com> wrote:
> The include/common.h is a collection of unrelated declarations,
> macros, etc.
>
> It is horrible to include such a cluttered header just for some
> timer functions.  Split out timer functions into include/timer.h.
>
> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
> ---
>
>  include/common.h |  8 +-------
>  include/time.h   | 16 ++++++++++++++++
>  2 files changed, 17 insertions(+), 7 deletions(-)
>  create mode 100644 include/time.h

Reviewed-by: Simon Glass <sjg@chromium.org>

[U-Boot] [PATCH 1/5] delay: collect {m, n, u}delay declarations to include/linux/delay.h

[Simon Glass]

On 20 December 2016 at 19:53, Masahiro Yamada
<yamada.masahiro@socionext.com> wrote:
> Currently, mdelay() and udelay() are declared in include/common.h,
> while ndelay() in include/linux/compat.h.  It would be nice to
> collect them into include/linux/delay.h like Linux.
>
> While we are here, fix the ndelay() implementation; I used the
> DIV_ROUND_UP() instead of (x)/1000 because we must wait *longer*
> than the given period of time.
>
> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
> ---
>
>  include/common.h       |  6 +-----
>  include/linux/compat.h |  2 --
>  include/linux/delay.h  | 24 ++++++++++++++++++++++++
>  lib/time.c             |  6 ------
>  4 files changed, 25 insertions(+), 13 deletions(-)
>  create mode 100644 include/linux/delay.h

Reviewed-by: Simon Glass <sjg@chromium.org>