ARM: versatile: convert sched_clock() to use new infrastructure

Convert versatile platforms to use the new sched_clock() infrastructure for extending 32bit counters to full 64-bit nanoseconds. Tested-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: versatile: convert sched_clock() to use new infrastructure
Convert versatile platforms to use the new sched_clock() infrastructure for extending 32bit counters to full 64-bit nanoseconds. Tested-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Russell King
1 parent f06a162462
Showing 5 changed files with 54 additions and 22 deletions Side-by-side Diff
arch/arm/Kconfig
arch/arm/mach-realview/core.c
arch/arm/mach-versatile/core.c
arch/arm/plat-versatile/include/plat/sched_clock.h
arch/arm/plat-versatile/sched-clock.c
@@ -236,6 +236,7 @@
 	bool "ARM Ltd. RealView family"
 	select ARM_AMBA
 	select COMMON_CLKDEV
+	select HAVE_SCHED_CLOCK
 	select ICST
 	select GENERIC_CLOCKEVENTS
 	select ARCH_WANT_OPTIONAL_GPIOLIB
@@ -250,6 +251,7 @@
 	select ARM_AMBA
 	select ARM_VIC
 	select COMMON_CLKDEV
+	select HAVE_SCHED_CLOCK
 	select ICST
 	select GENERIC_CLOCKEVENTS
 	select ARCH_WANT_OPTIONAL_GPIOLIB
@@ -52,6 +52,8 @@
 #include <mach/irqs.h>
 #include <plat/timer-sp.h>
  
+#include <plat/sched_clock.h>
+
 #include "core.h"
  
 /* used by entry-macro.S and platsmp.c */
@@ -658,6 +660,12 @@
 #endif	/* CONFIG_LEDS */
  
 /*
+ * The sched_clock counter
+ */
+#define REFCOUNTER		(__io_address(REALVIEW_SYS_BASE) + \
+				 REALVIEW_SYS_24MHz_OFFSET)
+
+/*
  * Where is the timer (VA)?
  */
 void __iomem *timer0_va_base;
@@ -671,6 +679,8 @@
 void __init realview_timer_init(unsigned int timer_irq)
 {
 	u32 val;
+
+	versatile_sched_clock_init(REFCOUNTER, 24000000);
  
 	/* 
 	 * set clock frequency: 
@@ -51,6 +51,8 @@
 #include <mach/platform.h>
 #include <plat/timer-sp.h>
  
+#include <plat/sched_clock.h>
+
 #include "core.h"
  
 /*
@@ -886,6 +888,12 @@
 }
  
 /*
+ * The sched_clock counter
+ */
+#define REFCOUNTER		(__io_address(VERSATILE_SYS_BASE) + \
+				 VERSATILE_SYS_24MHz_OFFSET)
+
+/*
  * Where is the timer (VA)?
  */
 #define TIMER0_VA_BASE		 __io_address(VERSATILE_TIMER0_1_BASE)
@@ -899,6 +907,8 @@
 static void __init versatile_timer_init(void)
 {
 	u32 val;
+
+	versatile_sched_clock_init(REFCOUNTER, 24000000);
  
 	/* 
 	 * set clock frequency: 
+#ifndef ARM_PLAT_SCHED_CLOCK_H
+#define ARM_PLAT_SCHED_CLOCK_H
+
+void versatile_sched_clock_init(void __iomem *, unsigned long);
+
+#endif
@@ -18,38 +18,42 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
-#include <linux/cnt32_to_63.h>
 #include <linux/io.h>
 #include <linux/sched.h>
-#include <asm/div64.h>
  
-#include <mach/hardware.h>
-#include <mach/platform.h>
+#include <asm/sched_clock.h>
+#include <plat/sched_clock.h>
  
-#ifdef VERSATILE_SYS_BASE
-#define REFCOUNTER	(__io_address(VERSATILE_SYS_BASE) + VERSATILE_SYS_24MHz_OFFSET)
-#endif
+static DEFINE_CLOCK_DATA(cd);
+static void __iomem *ctr;
  
-#ifdef REALVIEW_SYS_BASE
-#define REFCOUNTER	(__io_address(REALVIEW_SYS_BASE) + REALVIEW_SYS_24MHz_OFFSET)
-#endif
-
 /*
- * This is the Realview and Versatile sched_clock implementation.  This
- * has a resolution of 41.7ns, and a maximum value of about 35583 days.
- *
- * The return value is guaranteed to be monotonic in that range as
- * long as there is always less than 89 seconds between successive
- * calls to this function.
+ * Constants generated by clocks_calc_mult_shift(m, s, 24MHz, NSEC_PER_SEC, 60).
+ * This gives a resolution of about 41ns and a wrap period of about 178s.
  */
+#define SC_MULT		2796202667u
+#define SC_SHIFT	26
+
 unsigned long long notrace sched_clock(void)
 {
-	unsigned long long v = cnt32_to_63(readl(REFCOUNTER));
+	if (ctr) {
+		u32 cyc = readl(ctr);
+		return cyc_to_fixed_sched_clock(&cd, cyc, (u32)~0,
+						SC_MULT, SC_SHIFT);
+	} else
+		return 0;
+}
  
-	/* the <<1 gets rid of the cnt_32_to_63 top bit saving on a bic insn */
-	v *= 125<<1;
-	do_div(v, 3<<1);
+static void notrace versatile_update_sched_clock(void)
+{
+	u32 cyc = readl(ctr);
+	update_sched_clock(&cd, cyc, (u32)~0);
+}
  
-	return v;
+void __init versatile_sched_clock_init(void __iomem *reg, unsigned long rate)
+{
+	ctr = reg;
+	init_fixed_sched_clock(&cd, versatile_update_sched_clock,
+			       32, rate, SC_MULT, SC_SHIFT);
 }
...	...	@@ -236,6 +236,7 @@
236	236	bool "ARM Ltd. RealView family"
237	237	select ARM_AMBA
238	238	select COMMON_CLKDEV
	239	+ select HAVE_SCHED_CLOCK
239	240	select ICST
240	241	select GENERIC_CLOCKEVENTS
241	242	select ARCH_WANT_OPTIONAL_GPIOLIB
...	...	@@ -250,6 +251,7 @@
250	251	select ARM_AMBA
251	252	select ARM_VIC
252	253	select COMMON_CLKDEV
	254	+ select HAVE_SCHED_CLOCK
253	255	select ICST
254	256	select GENERIC_CLOCKEVENTS
255	257	select ARCH_WANT_OPTIONAL_GPIOLIB
...	...	@@ -52,6 +52,8 @@
52	52	#include <mach/irqs.h>
53	53	#include <plat/timer-sp.h>
54	54
	55	+#include <plat/sched_clock.h>
	56	+
55	57	#include "core.h"
56	58
57	59	/* used by entry-macro.S and platsmp.c */
...	...	@@ -658,6 +660,12 @@
658	660	#endif /* CONFIG_LEDS */
659	661
660	662	/*
	663	+ * The sched_clock counter
	664	+ */
	665	+#define REFCOUNTER (__io_address(REALVIEW_SYS_BASE) + \
	666	+ REALVIEW_SYS_24MHz_OFFSET)
	667	+
	668	+/*
661	669	* Where is the timer (VA)?
662	670	*/
663	671	void __iomem *timer0_va_base;
...	...	@@ -671,6 +679,8 @@
671	679	void __init realview_timer_init(unsigned int timer_irq)
672	680	{
673	681	u32 val;
	682	+
	683	+ versatile_sched_clock_init(REFCOUNTER, 24000000);
674	684
675	685	/*
676	686	* set clock frequency:
...	...	@@ -51,6 +51,8 @@
51	51	#include <mach/platform.h>
52	52	#include <plat/timer-sp.h>
53	53
	54	+#include <plat/sched_clock.h>
	55	+
54	56	#include "core.h"
55	57
56	58	/*
...	...	@@ -886,6 +888,12 @@
886	888	}
887	889
888	890	/*
	891	+ * The sched_clock counter
	892	+ */
	893	+#define REFCOUNTER (__io_address(VERSATILE_SYS_BASE) + \
	894	+ VERSATILE_SYS_24MHz_OFFSET)
	895	+
	896	+/*
889	897	* Where is the timer (VA)?
890	898	*/
891	899	#define TIMER0_VA_BASE __io_address(VERSATILE_TIMER0_1_BASE)
...	...	@@ -899,6 +907,8 @@
899	907	static void __init versatile_timer_init(void)
900	908	{
901	909	u32 val;
	910	+
	911	+ versatile_sched_clock_init(REFCOUNTER, 24000000);
902	912
903	913	/*
904	914	* set clock frequency:
	1	+#ifndef ARM_PLAT_SCHED_CLOCK_H
	2	+#define ARM_PLAT_SCHED_CLOCK_H
	3	+
	4	+void versatile_sched_clock_init(void __iomem *, unsigned long);
	5	+
	6	+#endif
...	...	@@ -18,38 +18,42 @@
18	18	* along with this program; if not, write to the Free Software
19	19	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20	20	*/
21		-#include <linux/cnt32_to_63.h>
22	21	#include <linux/io.h>
23	22	#include <linux/sched.h>
24		-#include <asm/div64.h>
25	23
26		-#include <mach/hardware.h>
27		-#include <mach/platform.h>
	24	+#include <asm/sched_clock.h>
	25	+#include <plat/sched_clock.h>
28	26
29		-#ifdef VERSATILE_SYS_BASE
30		-#define REFCOUNTER (__io_address(VERSATILE_SYS_BASE) + VERSATILE_SYS_24MHz_OFFSET)
31		-#endif
	27	+static DEFINE_CLOCK_DATA(cd);
	28	+static void __iomem *ctr;
32	29
33		-#ifdef REALVIEW_SYS_BASE
34		-#define REFCOUNTER (__io_address(REALVIEW_SYS_BASE) + REALVIEW_SYS_24MHz_OFFSET)
35		-#endif
36		-
37	30	/*
38		- * This is the Realview and Versatile sched_clock implementation. This
39		- * has a resolution of 41.7ns, and a maximum value of about 35583 days.
40		- *
41		- * The return value is guaranteed to be monotonic in that range as
42		- * long as there is always less than 89 seconds between successive
43		- * calls to this function.
	31	+ * Constants generated by clocks_calc_mult_shift(m, s, 24MHz, NSEC_PER_SEC, 60).
	32	+ * This gives a resolution of about 41ns and a wrap period of about 178s.
44	33	*/
	34	+#define SC_MULT 2796202667u
	35	+#define SC_SHIFT 26
	36	+
45	37	unsigned long long notrace sched_clock(void)
46	38	{
47		- unsigned long long v = cnt32_to_63(readl(REFCOUNTER));
	39	+ if (ctr) {
	40	+ u32 cyc = readl(ctr);
	41	+ return cyc_to_fixed_sched_clock(&cd, cyc, (u32)~0,
	42	+ SC_MULT, SC_SHIFT);
	43	+ } else
	44	+ return 0;
	45	+}
48	46
49		- /* the <<1 gets rid of the cnt_32_to_63 top bit saving on a bic insn */
50		- v *= 125<<1;
51		- do_div(v, 3<<1);
	47	+static void notrace versatile_update_sched_clock(void)
	48	+{
	49	+ u32 cyc = readl(ctr);
	50	+ update_sched_clock(&cd, cyc, (u32)~0);
	51	+}
52	52
53		- return v;
	53	+void __init versatile_sched_clock_init(void __iomem *reg, unsigned long rate)
	54	+{
	55	+ ctr = reg;
	56	+ init_fixed_sched_clock(&cd, versatile_update_sched_clock,
	57	+ 32, rate, SC_MULT, SC_SHIFT);
54	58	}