---

yaml
---
r: 372104
b: refs/heads/master
c: e8db288
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 0c91e7e07ebf08092bf8e28d8cd8d420732fc716
+refs/heads/master: e8db288e05e588ad3f416b3a24354d60d02f35f2

trunk/arch/arm/Kconfig

@@ -1599,6 +1599,14 @@ config HAVE_ARM_TWD
 	help
 	  This options enables support for the ARM timer and watchdog unit
 
+config MCPM
+	bool "Multi-Cluster Power Management"
+	depends on CPU_V7 && SMP
+	help
+	  This option provides the common power management infrastructure
+	  for (multi-)cluster based systems, such as big.LITTLE based
+	  systems.
+
 choice
 	prompt "Memory split"
 	default VMSPLIT_3G

trunk/arch/arm/common/Makefile

@@ -11,3 +11,4 @@ obj-$(CONFIG_SHARP_PARAM)	+= sharpsl_param.o
 obj-$(CONFIG_SHARP_SCOOP)	+= scoop.o
 obj-$(CONFIG_PCI_HOST_ITE8152)  += it8152.o
 obj-$(CONFIG_ARM_TIMER_SP804)	+= timer-sp.o
+obj-$(CONFIG_MCPM)		+= mcpm_head.o mcpm_entry.o

trunk/arch/arm/common/mcpm_entry.c

@@ -0,0 +1,22 @@
+/*
+ * arch/arm/common/mcpm_entry.c -- entry point for multi-cluster PM
+ *
+ * Created by:  Nicolas Pitre, March 2012
+ * Copyright:   (C) 2012-2013  Linaro Limited
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <asm/mcpm.h>
+#include <asm/cacheflush.h>
+
+extern unsigned long mcpm_entry_vectors[MAX_NR_CLUSTERS][MAX_CPUS_PER_CLUSTER];
+
+void mcpm_set_entry_vector(unsigned cpu, unsigned cluster, void *ptr)
+{
+	unsigned long val = ptr ? virt_to_phys(ptr) : 0;
+	mcpm_entry_vectors[cluster][cpu] = val;
+	sync_cache_w(&mcpm_entry_vectors[cluster][cpu]);
+}

trunk/arch/arm/common/mcpm_head.S

@@ -0,0 +1,86 @@
+/*
+ * arch/arm/common/mcpm_head.S -- kernel entry point for multi-cluster PM
+ *
+ * Created by:  Nicolas Pitre, March 2012
+ * Copyright:   (C) 2012-2013  Linaro Limited
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/linkage.h>
+#include <asm/mcpm.h>
+
+	.macro	pr_dbg	string
+#if defined(CONFIG_DEBUG_LL) && defined(DEBUG)
+	b	1901f
+1902:	.asciz	"CPU"
+1903:	.asciz	" cluster"
+1904:	.asciz	": \string"
+	.align
+1901:	adr	r0, 1902b
+	bl	printascii
+	mov	r0, r9
+	bl	printhex8
+	adr	r0, 1903b
+	bl	printascii
+	mov	r0, r10
+	bl	printhex8
+	adr	r0, 1904b
+	bl	printascii
+#endif
+	.endm
+
+	.arm
+	.align
+
+ENTRY(mcpm_entry_point)
+
+ THUMB(	adr	r12, BSYM(1f)	)
+ THUMB(	bx	r12		)
+ THUMB(	.thumb			)
+1:
+	mrc	p15, 0, r0, c0, c0, 5		@ MPIDR
+	ubfx	r9, r0, #0, #8			@ r9 = cpu
+	ubfx	r10, r0, #8, #8			@ r10 = cluster
+	mov	r3, #MAX_CPUS_PER_CLUSTER
+	mla	r4, r3, r10, r9			@ r4 = canonical CPU index
+	cmp	r4, #(MAX_CPUS_PER_CLUSTER * MAX_NR_CLUSTERS)
+	blo	2f
+
+	/* We didn't expect this CPU.  Try to cheaply make it quiet. */
+1:	wfi
+	wfe
+	b	1b
+
+2:	pr_dbg	"kernel mcpm_entry_point\n"
+
+	/*
+	 * MMU is off so we need to get to mcpm_entry_vectors in a
+	 * position independent way.
+	 */
+	adr	r5, 3f
+	ldr	r6, [r5]
+	add	r6, r5, r6			@ r6 = mcpm_entry_vectors
+
+mcpm_entry_gated:
+	ldr	r5, [r6, r4, lsl #2]		@ r5 = CPU entry vector
+	cmp	r5, #0
+	wfeeq
+	beq	mcpm_entry_gated
+	pr_dbg	"released\n"
+	bx	r5
+
+	.align	2
+
+3:	.word	mcpm_entry_vectors - .
+
+ENDPROC(mcpm_entry_point)
+
+	.bss
+	.align	5
+
+	.type	mcpm_entry_vectors, #object
+ENTRY(mcpm_entry_vectors)
+	.space	4 * MAX_NR_CLUSTERS * MAX_CPUS_PER_CLUSTER

trunk/arch/arm/include/asm/mcpm.h

@@ -0,0 +1,42 @@
+/*
+ * arch/arm/include/asm/mcpm.h
+ *
+ * Created by:  Nicolas Pitre, April 2012
+ * Copyright:   (C) 2012-2013  Linaro Limited
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef MCPM_H
+#define MCPM_H
+
+/*
+ * Maximum number of possible clusters / CPUs per cluster.
+ *
+ * This should be sufficient for quite a while, while keeping the
+ * (assembly) code simpler.  When this starts to grow then we'll have
+ * to consider dynamic allocation.
+ */
+#define MAX_CPUS_PER_CLUSTER	4
+#define MAX_NR_CLUSTERS		2
+
+#ifndef __ASSEMBLY__
+
+/*
+ * Platform specific code should use this symbol to set up secondary
+ * entry location for processors to use when released from reset.
+ */
+extern void mcpm_entry_point(void);
+
+/*
+ * This is used to indicate where the given CPU from given cluster should
+ * branch once it is ready to re-enter the kernel using ptr, or NULL if it
+ * should be gated.  A gated CPU is held in a WFE loop until its vector
+ * becomes non NULL.
+ */
+void mcpm_set_entry_vector(unsigned cpu, unsigned cluster, void *ptr);
+
+#endif /* ! __ASSEMBLY__ */
+#endif