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From: santosh.shilimkar@ti•com (Santosh Shilimkar)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 01/16] ARM: b.L: secondary kernel entry code
Date: Fri, 11 Jan 2013 22:46:07 +0530	[thread overview]
Message-ID: <50F048D7.6000904@ti.com> (raw)
In-Reply-To: <1357777251-13541-2-git-send-email-nicolas.pitre@linaro.org>

On Thursday 10 January 2013 05:50 AM, Nicolas Pitre wrote:
> CPUs in a big.LITTLE systems have special needs when entering the kernel
> due to a hotplug event, or when resuming from a deep sleep mode.
>
> This is vectorized so multiple CPUs can enter the kernel in parallel
> without serialization.
>
> Only the basic structure is introduced here.  This will be extended
> later.
>
> TODO: MPIDR based indexing should eventually be made runtime adjusted.
>
> Signed-off-by: Nicolas Pitre <nico@linaro•org>
> ---

[..]

> diff --git a/arch/arm/common/Makefile b/arch/arm/common/Makefile
> index e8a4e58f1b..50880c494f 100644
> --- a/arch/arm/common/Makefile
> +++ b/arch/arm/common/Makefile
> @@ -13,3 +13,6 @@ 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-$(CONFIG_FIQ_GLUE)		+= fiq_glue.o fiq_glue_setup.o
> +obj-$(CONFIG_FIQ_DEBUGGER)	+= fiq_debugger.o
> +obj-$(CONFIG_BIG_LITTLE)	+= bL_head.o bL_entry.o
> diff --git a/arch/arm/common/bL_entry.c b/arch/arm/common/bL_entry.c
> new file mode 100644
> index 0000000000..80fff49417
> --- /dev/null
> +++ b/arch/arm/common/bL_entry.c
> @@ -0,0 +1,30 @@
> +/*
> + * arch/arm/common/bL_entry.c -- big.LITTLE kernel re-entry point
> + *
> + * Created by:  Nicolas Pitre, March 2012
> + * Copyright:   (C) 2012  Linaro Limited
2013 now :-)
Looks like you need to update rest of the patches as well.
> + *
> + * 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/kernel.h>
> +#include <linux/init.h>
> +
> +#include <asm/bL_entry.h>
> +#include <asm/barrier.h>
> +#include <asm/proc-fns.h>
> +#include <asm/cacheflush.h>
> +
> +extern volatile unsigned long bL_entry_vectors[BL_NR_CLUSTERS][BL_CPUS_PER_CLUSTER];
> +
> +void bL_set_entry_vector(unsigned cpu, unsigned cluster, void *ptr)
> +{
> +	unsigned long val = ptr ? virt_to_phys(ptr) : 0;
> +	bL_entry_vectors[cluster][cpu] = val;
> +	smp_wmb();
> +	__cpuc_flush_dcache_area((void *)&bL_entry_vectors[cluster][cpu], 4);
> +	outer_clean_range(__pa(&bL_entry_vectors[cluster][cpu]),
> +			  __pa(&bL_entry_vectors[cluster][cpu + 1]));
> +}
I had the same question about smp_wmb() as Catalin but after following
rest of the comments, I understand it will be removed so thats good.

> diff --git a/arch/arm/common/bL_head.S b/arch/arm/common/bL_head.S
> new file mode 100644
> index 0000000000..9d351f2b4c
> --- /dev/null
> +++ b/arch/arm/common/bL_head.S
> @@ -0,0 +1,81 @@
> +/*
> + * arch/arm/common/bL_head.S -- big.LITTLE kernel re-entry point
> + *
> + * Created by:  Nicolas Pitre, March 2012
> + * Copyright:   (C) 2012  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/bL_entry.h>
> +
> +	.macro	pr_dbg	cpu, string
> +#if defined(CONFIG_DEBUG_LL) && defined(DEBUG)
> +	b	1901f
> +1902:	.ascii	"CPU 0: \0CPU 1: \0CPU 2: \0CPU 3: \0"
> +	.ascii	"CPU 4: \0CPU 5: \0CPU 6: \0CPU 7: \0"
> +1903:	.asciz	"\string"
> +	.align
> +1901:	adr	r0, 1902b
> +	add	r0, r0, \cpu, lsl #3
> +	bl	printascii
> +	adr	r0, 1903b
> +	bl	printascii
> +#endif
> +	.endm
> +
> +	.arm
> +	.align
> +
> +ENTRY(bL_entry_point)
> +
> + THUMB(	adr	r12, BSYM(1f)	)
> + THUMB(	bx	r12		)
> + THUMB(	.thumb			)
> +1:
> +	mrc	p15, 0, r0, c0, c0, 5
> +	ubfx	r9, r0, #0, #4			@ r9 = cpu
> +	ubfx	r10, r0, #8, #4			@ r10 = cluster
> +	mov	r3, #BL_CPUS_PER_CLUSTER
> +	mla	r4, r3, r10, r9			@ r4 = canonical CPU index
> +	cmp	r4, #(BL_CPUS_PER_CLUSTER * BL_NR_CLUSTERS)
> +	blo	2f
> +
> +	/* We didn't expect this CPU.  Try to make it quiet. */
> +1:	wfi
> +	wfe

Why do you need a wfe followed by wif ?
Just curious.

Regards
Santosh

  parent reply	other threads:[~2013-01-11 17:16 UTC|newest]

Thread overview: 132+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-01-10  0:20 [PATCH 00/16] big.LITTLE low-level CPU and cluster power management Nicolas Pitre
2013-01-10  0:20 ` [PATCH 01/16] ARM: b.L: secondary kernel entry code Nicolas Pitre
2013-01-10  7:12   ` Stephen Boyd
2013-01-10 15:30     ` Nicolas Pitre
2013-01-10 15:34   ` Catalin Marinas
2013-01-10 16:47     ` Nicolas Pitre
2013-01-11 11:45       ` Catalin Marinas
2013-01-11 12:05         ` Lorenzo Pieralisi
2013-01-11 12:19         ` Dave Martin
2013-01-10 23:05   ` Will Deacon
2013-01-11  1:26     ` Nicolas Pitre
2013-01-11 10:55       ` Will Deacon
2013-01-11 11:35         ` Dave Martin
2013-01-11 17:16   ` Santosh Shilimkar [this message]
2013-01-11 18:10     ` Nicolas Pitre
2013-01-11 18:30       ` Santosh Shilimkar
2013-03-07  7:37   ` Pavel Machek
2013-03-07  8:57     ` Nicolas Pitre
2013-01-10  0:20 ` [PATCH 02/16] ARM: b.L: introduce the CPU/cluster power API Nicolas Pitre
2013-01-10 23:08   ` Will Deacon
2013-01-11  2:30     ` Nicolas Pitre
2013-01-11 10:58       ` Will Deacon
2013-01-11 11:29       ` Dave Martin
2013-01-11 17:26   ` Santosh Shilimkar
2013-01-11 18:33     ` Nicolas Pitre
2013-01-11 18:41       ` Santosh Shilimkar
2013-01-11 19:54         ` Nicolas Pitre
2013-01-10  0:20 ` [PATCH 03/16] ARM: b.L: introduce helpers for platform coherency exit/setup Nicolas Pitre
2013-01-10 12:01   ` Dave Martin
2013-01-10 19:04     ` Nicolas Pitre
2013-01-11 11:30       ` Dave Martin
2013-01-10 16:53   ` Catalin Marinas
2013-01-10 17:59     ` Nicolas Pitre
2013-01-10 21:50       ` Catalin Marinas
2013-01-10 22:31         ` Nicolas Pitre
2013-01-11 10:36           ` Dave Martin
2013-01-10 22:32     ` Nicolas Pitre
2013-01-10 23:13   ` Will Deacon
2013-01-11  1:50     ` Nicolas Pitre
2013-01-11 11:09       ` Dave Martin
2013-01-11 17:46   ` Santosh Shilimkar
2013-01-11 18:07     ` Dave Martin
2013-01-11 18:34       ` Santosh Shilimkar
2013-01-14 17:08   ` Dave Martin
2013-01-14 17:15     ` Catalin Marinas
2013-01-14 18:10       ` Dave Martin
2013-01-14 21:34         ` Catalin Marinas
2013-01-10  0:20 ` [PATCH 04/16] ARM: b.L: Add baremetal voting mutexes Nicolas Pitre
2013-01-10 23:18   ` Will Deacon
2013-01-11  3:15     ` Nicolas Pitre
2013-01-11 11:03       ` Will Deacon
2013-01-11 16:57       ` Dave Martin
2013-01-10  0:20 ` [PATCH 05/16] ARM: bL_head: vlock-based first man election Nicolas Pitre
2013-01-10  0:20 ` [PATCH 06/16] ARM: b.L: generic SMP secondary bringup and hotplug support Nicolas Pitre
2013-01-11 18:02   ` Santosh Shilimkar
2013-01-14 18:05     ` Achin Gupta
2013-01-15  6:32       ` Santosh Shilimkar
2013-01-15 11:18         ` Achin Gupta
2013-01-15 11:26           ` Santosh Shilimkar
2013-01-15 18:53           ` Dave Martin
2013-01-14 16:35   ` Will Deacon
2013-01-14 16:51     ` Nicolas Pitre
2013-01-15 19:09       ` Dave Martin
2013-01-10  0:20 ` [PATCH 07/16] ARM: bL_platsmp.c: close the kernel entry gate before hot-unplugging a CPU Nicolas Pitre
2013-01-14 16:37   ` Will Deacon
2013-01-14 16:53     ` Nicolas Pitre
2013-01-14 17:00       ` Will Deacon
2013-01-14 17:11         ` Catalin Marinas
2013-01-14 17:15         ` Nicolas Pitre
2013-01-14 17:23           ` Will Deacon
2013-01-14 18:26           ` Russell King - ARM Linux
2013-01-14 18:49             ` Nicolas Pitre
2013-01-15 18:40             ` Dave Martin
2013-01-16 16:06               ` Catalin Marinas
2013-01-10  0:20 ` [PATCH 08/16] ARM: bL_platsmp.c: make sure the GIC interface of a dying CPU is disabled Nicolas Pitre
2013-01-11 18:07   ` Santosh Shilimkar
2013-01-11 19:07     ` Nicolas Pitre
2013-01-12  6:50       ` Santosh Shilimkar
2013-01-12 16:47         ` Nicolas Pitre
2013-01-13  4:37           ` Santosh Shilimkar
2013-01-14 17:53           ` Lorenzo Pieralisi
2013-01-14 16:39   ` Will Deacon
2013-01-14 16:54     ` Nicolas Pitre
2013-01-14 17:02       ` Will Deacon
2013-01-14 17:18         ` Nicolas Pitre
2013-01-14 17:24           ` Will Deacon
2013-01-14 17:56             ` Lorenzo Pieralisi
2013-01-10  0:20 ` [PATCH 09/16] ARM: vexpress: Select the correct SMP operations at run-time Nicolas Pitre
2013-01-10  0:20 ` [PATCH 10/16] ARM: vexpress: introduce DCSCB support Nicolas Pitre
2013-01-11 18:12   ` Santosh Shilimkar
2013-01-11 19:13     ` Nicolas Pitre
2013-01-12  6:52       ` Santosh Shilimkar
2013-01-10  0:20 ` [PATCH 11/16] ARM: vexpress/dcscb: add CPU use counts to the power up/down API implementation Nicolas Pitre
2013-01-10  0:20 ` [PATCH 12/16] ARM: vexpress/dcscb: do not hardcode number of CPUs per cluster Nicolas Pitre
2013-01-10  0:20 ` [PATCH 13/16] drivers: misc: add ARM CCI support Nicolas Pitre
2013-01-11 18:20   ` Santosh Shilimkar
2013-01-11 19:22     ` Nicolas Pitre
2013-01-12  6:53       ` Santosh Shilimkar
2013-01-15 18:34       ` Dave Martin
2013-01-10  0:20 ` [PATCH 14/16] ARM: TC2: ensure powerdown-time data is flushed from cache Nicolas Pitre
2013-01-10 18:50   ` Dave Martin
2013-01-10 19:13     ` Nicolas Pitre
2013-01-11 11:38       ` Dave Martin
2013-01-10  0:20 ` [PATCH 15/16] ARM: vexpress/dcscb: handle platform coherency exit/setup and CCI Nicolas Pitre
2013-01-10 12:05   ` Dave Martin
2013-01-11 18:27   ` Santosh Shilimkar
2013-01-11 19:28     ` Nicolas Pitre
2013-01-12  7:21       ` Santosh Shilimkar
2013-01-14 12:25         ` Lorenzo Pieralisi
2013-01-15  6:23           ` Santosh Shilimkar
2013-01-15 18:20             ` Dave Martin
2013-01-16  6:33               ` Santosh Shilimkar
2013-01-16 10:03                 ` Lorenzo Pieralisi
2013-01-16 10:12                   ` Santosh Shilimkar
2013-01-10  0:20 ` [PATCH 16/16] ARM: vexpress/dcscb: probe via device tree Nicolas Pitre
2013-01-10  0:46 ` [PATCH 00/16] big.LITTLE low-level CPU and cluster power management Rob Herring
2013-01-10  5:04   ` Nicolas Pitre
2013-01-10 23:01 ` Will Deacon
2013-01-14  9:56 ` Joseph Lo
2013-01-14 14:05   ` Nicolas Pitre
2013-01-15  2:44     ` Joseph Lo
2013-01-15 16:44       ` Nicolas Pitre
2013-01-16 16:02         ` Catalin Marinas
2013-01-16 21:18           ` Nicolas Pitre
2013-01-17 17:55             ` Catalin Marinas
2013-01-15 18:31     ` Dave Martin
2013-03-07  8:27 ` Pavel Machek
2013-03-07  9:12   ` Nicolas Pitre
2013-03-07  9:40     ` Pavel Machek
2013-03-07  9:56       ` Nicolas Pitre
2013-03-07 14:51         ` Pavel Machek
2013-03-07 15:42           ` Nicolas Pitre

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