From: santosh.shilimkar@ti•com (Santosh Shilimkar)
To: linux-arm-kernel@lists•infradead.org
Subject: [RFC PATCH 12/17] ARM: kernel: add SCU reset hook
Date: Thu, 07 Jul 2011 19:14:02 -0700 [thread overview]
Message-ID: <4E1667EA.5090509@ti.com> (raw)
In-Reply-To: <1310053830-23779-13-git-send-email-lorenzo.pieralisi@arm.com>
On 7/7/2011 8:50 AM, Lorenzo Pieralisi wrote:
> When a CLUSTER is powered down the SCU must be reinitialized on
> warm-boot.
> This patch adds a hook to reset the SCU, which implies invalidating
> TAG RAMs and renabling it.
>
> The scu virtual address is saved in a static variable when the SCU
> is first enabled at boot; this allows common idle code to be
> generic and avoid relying on platform code to get the address at
> run-time.
> On warm-boot the SCU TAG RAM is invalidated and the SCU enabled if
> it is not already enabled.
>
> The reset can be skipped altogether thanks to save/restore
> framework flags.
>
> Flushing D$ cache is cumbersome since the system just comes out of
> reset, which invalidates caches in the process if needed (A9), that
> is why the scu_enable function is not reused as it is to reset the SCU.
>
> If the init function is extended, there might not be a need for
> a SCU specific hook, since the init function can be reused to
> reinitialize the SCU at boot provided it is removed from the init
> section and kept in memory.
>
> Signed-off-by: Lorenzo Pieralisi<lorenzo.pieralisi@arm•com>
> ---
> arch/arm/include/asm/smp_scu.h | 3 ++-
> arch/arm/kernel/smp_scu.c | 33 ++++++++++++++++++++++++++++++---
> 2 files changed, 32 insertions(+), 4 deletions(-)
>
> diff --git a/arch/arm/include/asm/smp_scu.h b/arch/arm/include/asm/smp_scu.h
> index 4eb6d00..cfaa68e 100644
> --- a/arch/arm/include/asm/smp_scu.h
> +++ b/arch/arm/include/asm/smp_scu.h
> @@ -8,7 +8,8 @@
> #ifndef __ASSEMBLER__
> unsigned int scu_get_core_count(void __iomem *);
> void scu_enable(void __iomem *);
> -int scu_power_mode(void __iomem *, unsigned int);
> +int scu_power_mode(unsigned int);
> +void scu_reset(void);
> #endif
>
> #endif
> diff --git a/arch/arm/kernel/smp_scu.c b/arch/arm/kernel/smp_scu.c
> index a1e757c..980ced9 100644
> --- a/arch/arm/kernel/smp_scu.c
> +++ b/arch/arm/kernel/smp_scu.c
> @@ -20,6 +20,7 @@
> #define SCU_INVALIDATE 0x0c
> #define SCU_FPGA_REVISION 0x10
>
> +static void __iomem *scu_va;
Change log and patch doesn't seems to match. I remember suggesting
this change to Russell when "scu_power_mode()" was introduced.
His preference was to have scu_base passed as part of the API.
> /*
> * Get the number of CPU cores from the SCU configuration
> */
> @@ -36,6 +37,7 @@ void __init scu_enable(void __iomem *scu_base)
> {
> u32 scu_ctrl;
>
> + scu_va = scu_base;
> scu_ctrl = __raw_readl(scu_base + SCU_CTRL);
> /* already enabled? */
> if (scu_ctrl& 1)
> @@ -59,7 +61,7 @@ void __init scu_enable(void __iomem *scu_base)
> * has the side effect of disabling coherency, caches must have been
> * flushed. Interrupts must also have been disabled.
> */
> -int scu_power_mode(void __iomem *scu_base, unsigned int mode)
> +int scu_power_mode(unsigned int mode)
> {
> unsigned int val;
> int cpu = smp_processor_id();
> @@ -67,9 +69,34 @@ int scu_power_mode(void __iomem *scu_base, unsigned int mode)
> if (mode> 3 || mode == 1 || cpu> 3)
> return -EINVAL;
>
> - val = __raw_readb(scu_base + SCU_CPU_STATUS + cpu)& ~0x03;
> + val = __raw_readb(scu_va + SCU_CPU_STATUS + cpu)& ~0x03;
> val |= mode;
> - __raw_writeb(val, scu_base + SCU_CPU_STATUS + cpu);
> + __raw_writeb(val, scu_va + SCU_CPU_STATUS + cpu);
>
> return 0;
> }
> +
> +/*
> + * Reinitialise the SCU after power-down
> + */
> +
> +void scu_reset(void)
> +{
> + u32 scu_ctrl;
> +
> + scu_ctrl = __raw_readl(scu_va + SCU_CTRL);
> + /* already enabled? */
> + if (scu_ctrl& 1)
> + return;
> + /*
> + * SCU TAGS should be invalidated on boot-up
> + */
> + __raw_writel(0xffff, scu_va + SCU_INVALIDATE);
> + /*
> + * Coming out of reset, dcache invalidated
> + * no need to go through the whole hog again
> + * just enable the SCU and pop out
> + */
> + scu_ctrl |= 1;
> + __raw_writel(scu_ctrl, scu_va + SCU_CTRL);
> +}
next prev parent reply other threads:[~2011-07-08 2:14 UTC|newest]
Thread overview: 90+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-07-07 15:50 [RFC PATCH 00/17] ARM: common idle infrastructure Lorenzo Pieralisi
2011-07-07 15:50 ` [PATCH 01/17] ARM: proc: add definition of cpu_reset for ARMv6 and ARMv7 cores Lorenzo Pieralisi
2011-07-08 1:12 ` Santosh Shilimkar
2011-07-08 8:22 ` Will Deacon
2011-07-09 10:14 ` Russell King - ARM Linux
2011-07-10 11:00 ` Will Deacon
2011-07-10 11:52 ` Russell King - ARM Linux
2011-07-10 13:21 ` Will Deacon
2011-07-07 15:50 ` [PATCH 02/17] ARM: Add cpu power management notifiers Lorenzo Pieralisi
2011-07-08 1:14 ` Santosh Shilimkar
2011-07-09 10:15 ` Russell King - ARM Linux
2011-07-09 21:32 ` Colin Cross
2011-07-07 15:50 ` [PATCH 03/17] ARM: gic: Use cpu pm notifiers to save gic state Lorenzo Pieralisi
2011-07-08 1:35 ` Santosh Shilimkar
2011-07-08 1:41 ` Colin Cross
2011-07-08 2:07 ` Santosh Shilimkar
2011-07-08 7:08 ` Kukjin Kim
2011-07-09 10:21 ` Russell King - ARM Linux
2011-07-09 22:10 ` Colin Cross
2011-07-09 22:33 ` Russell King - ARM Linux
2011-07-09 23:01 ` Colin Cross
2011-07-09 23:05 ` Russell King - ARM Linux
2011-07-09 23:24 ` Colin Cross
2011-07-10 0:10 ` Santosh Shilimkar
2011-07-21 8:32 ` Santosh Shilimkar
2011-07-21 10:27 ` Lorenzo Pieralisi
2011-07-21 10:46 ` Santosh Shilimkar
2011-07-21 19:06 ` Colin Cross
2011-07-22 5:10 ` Santosh Shilimkar
2011-07-22 5:21 ` Colin Cross
2011-08-17 16:15 ` Santosh
2011-07-07 15:50 ` [PATCH 04/17] ARM: vfp: Use cpu pm notifiers to save vfp state Lorenzo Pieralisi
2011-07-09 10:44 ` Russell King - ARM Linux
2011-07-09 14:32 ` Russell King - ARM Linux
2011-07-07 15:50 ` [RFC PATCH 05/17] ARM: kernel: save/restore kernel IF Lorenzo Pieralisi
2011-07-08 1:45 ` Santosh Shilimkar
2011-07-08 8:39 ` Lorenzo Pieralisi
2011-07-08 16:12 ` Frank Hofmann
2011-07-11 14:00 ` Lorenzo Pieralisi
2011-07-11 14:31 ` Frank Hofmann
2011-07-11 16:02 ` Lorenzo Pieralisi
2011-07-11 16:57 ` Frank Hofmann
2011-07-11 18:05 ` Lorenzo Pieralisi
2011-07-11 18:40 ` Russell King - ARM Linux
2011-07-11 18:51 ` Colin Cross
2011-07-11 19:19 ` Russell King - ARM Linux
2011-07-11 19:38 ` Colin Cross
2011-07-11 20:09 ` Santosh Shilimkar
2011-07-11 20:05 ` Santosh Shilimkar
2011-07-11 20:14 ` Russell King - ARM Linux
2011-07-11 21:31 ` Santosh Shilimkar
2011-07-12 10:12 ` Lorenzo Pieralisi
2011-07-12 10:19 ` Russell King - ARM Linux
2011-07-09 8:38 ` Russell King - ARM Linux
2011-07-09 8:45 ` Russell King - ARM Linux
2011-07-11 15:36 ` Lorenzo Pieralisi
2011-07-07 15:50 ` [RFC PATCH 06/17] ARM: kernel: save/restore generic infrastructure Lorenzo Pieralisi
2011-07-08 1:58 ` Santosh Shilimkar
2011-07-08 10:33 ` Lorenzo Pieralisi
2011-07-09 10:01 ` Russell King - ARM Linux
2011-07-11 11:33 ` Lorenzo Pieralisi
2011-07-28 16:22 ` Amit Kachhap
2011-07-28 18:17 ` Lorenzo Pieralisi
2011-07-07 15:50 ` [RFC PATCH 07/17] ARM: kernel: save/restore v7 assembly helpers Lorenzo Pieralisi
2011-07-07 15:50 ` [RFC PATCH 08/17] ARM: kernel: save/restore arch runtime support Lorenzo Pieralisi
2011-07-07 15:50 ` [RFC PATCH 09/17] ARM: kernel: v7 resets support Lorenzo Pieralisi
2011-07-07 15:50 ` [RFC PATCH 10/17] ARM: kernel: save/restore v7 infrastructure support Lorenzo Pieralisi
2011-07-07 15:50 ` [RFC PATCH 11/17] ARM: kernel: add support for Lamport's bakery locks Lorenzo Pieralisi
2011-07-07 15:50 ` [RFC PATCH 12/17] ARM: kernel: add SCU reset hook Lorenzo Pieralisi
2011-07-08 2:14 ` Santosh Shilimkar [this message]
2011-07-08 9:47 ` Lorenzo Pieralisi
2011-07-07 15:50 ` [RFC PATCH 13/17] ARM: mm: L2x0 save/restore support Lorenzo Pieralisi
2011-07-07 22:06 ` Colin Cross
2011-07-08 8:25 ` Lorenzo Pieralisi
2011-07-08 2:19 ` Santosh Shilimkar
2011-07-08 10:54 ` Lorenzo Pieralisi
2011-07-07 15:50 ` [RFC PATCH 14/17] ARM: kernel: save/restore 1:1 page tables Lorenzo Pieralisi
2011-07-08 2:24 ` Santosh Shilimkar
2011-07-08 10:48 ` Lorenzo Pieralisi
2011-07-07 15:50 ` [RFC PATCH 15/17] ARM: perf: use cpu pm notifiers to save pmu state Lorenzo Pieralisi
2011-07-07 15:50 ` [RFC PATCH 16/17] ARM: PM: enhance idle pm notifiers Lorenzo Pieralisi
2011-07-07 21:20 ` Colin Cross
2011-07-08 9:04 ` Lorenzo Pieralisi
2011-07-07 15:50 ` [RFC PATCH 17/17] ARM: kernel: save/restore build infrastructure Lorenzo Pieralisi
2011-07-08 2:29 ` Santosh Shilimkar
2011-07-08 15:14 ` Lorenzo Pieralisi
2011-07-26 12:14 ` Amit Kachhap
2011-07-27 8:48 ` Lorenzo Pieralisi
2011-07-07 17:15 ` [RFC PATCH 00/17] ARM: common idle infrastructure Russell King - ARM Linux
2011-07-08 7:56 ` Lorenzo Pieralisi
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