diff options
| -rw-r--r-- | arch/arm/Kconfig | 8 | ||||
| -rw-r--r-- | arch/arm/common/Makefile | 1 | ||||
| -rw-r--r-- | arch/arm/common/mcpm_entry.c | 22 | ||||
| -rw-r--r-- | arch/arm/common/mcpm_head.S | 86 | ||||
| -rw-r--r-- | arch/arm/include/asm/mcpm.h | 42 |
5 files changed, 159 insertions, 0 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 2c3bdce15134..2d17275b5df2 100644 --- a/arch/arm/Kconfig +++ b/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 diff --git a/arch/arm/common/Makefile b/arch/arm/common/Makefile index dc8dd0de5c0f..b070671033ae 100644 --- a/arch/arm/common/Makefile +++ b/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 diff --git a/arch/arm/common/mcpm_entry.c b/arch/arm/common/mcpm_entry.c new file mode 100644 index 000000000000..7cbf70051ea7 --- /dev/null +++ b/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]); +} diff --git a/arch/arm/common/mcpm_head.S b/arch/arm/common/mcpm_head.S new file mode 100644 index 000000000000..68c9903075a9 --- /dev/null +++ b/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 diff --git a/arch/arm/include/asm/mcpm.h b/arch/arm/include/asm/mcpm.h new file mode 100644 index 000000000000..470a417d1351 --- /dev/null +++ b/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 |