Hi Bjorn,
On 5/24/2018 11:09 PM, Bjorn Andersson wrote:
> On Tue 06 Mar 06:38 PST 2018, Sricharan R wrote:
>
>> From: Stephen Boyd <sboyd@xxxxxxxxxxxxxx>
>>
>> Krait CPUs have a handful of L2 cache controller registers that
>> live behind a cp15 based indirection register. First you program
>> the indirection register (l2cpselr) to point the L2 'window'
>> register (l2cpdr) at what you want to read/write. Then you
>> read/write the 'window' register to do what you want. The
>> l2cpselr register is not banked per-cpu so we must lock around
>> accesses to it to prevent other CPUs from re-pointing l2cpdr
>> underneath us.
>>
>> Cc: Mark Rutland <mark.rutland@xxxxxxx>
>> Cc: Russell King <linux@xxxxxxxxxxxxxxxx>
>> Signed-off-by: Stephen Boyd <sboyd@xxxxxxxxxxxxxx>
>
> This should have your signed-off-by here as well.
>
ok.
> Apart from that:
>
> Acked-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
>
Thanks.
Regards,
Sricharan
> Regards,
> Bjorn
>
>> ---
>> arch/arm/common/Kconfig | 3 ++
>> arch/arm/common/Makefile | 1 +
>> arch/arm/common/krait-l2-accessors.c | 48 +++++++++++++++++++++++++++++++
>> arch/arm/include/asm/krait-l2-accessors.h | 10 +++++++
>> 4 files changed, 62 insertions(+)
>> create mode 100644 arch/arm/common/krait-l2-accessors.c
>> create mode 100644 arch/arm/include/asm/krait-l2-accessors.h
>>
>> diff --git a/arch/arm/common/Kconfig b/arch/arm/common/Kconfig
>> index e5ad070..c8e1986 100644
>> --- a/arch/arm/common/Kconfig
>> +++ b/arch/arm/common/Kconfig
>> @@ -7,6 +7,9 @@ config DMABOUNCE
>> bool
>> select ZONE_DMA
>>
>> +config KRAIT_L2_ACCESSORS
>> + bool
>> +
>> config SHARP_LOCOMO
>> bool
>>
>> diff --git a/arch/arm/common/Makefile b/arch/arm/common/Makefile
>> index 70b4a14..eec6cd1 100644
>> --- a/arch/arm/common/Makefile
>> +++ b/arch/arm/common/Makefile
>> @@ -7,6 +7,7 @@ obj-y += firmware.o
>>
>> obj-$(CONFIG_SA1111) += sa1111.o
>> obj-$(CONFIG_DMABOUNCE) += dmabounce.o
>> +obj-$(CONFIG_KRAIT_L2_ACCESSORS) += krait-l2-accessors.o
>> obj-$(CONFIG_SHARP_LOCOMO) += locomo.o
>> obj-$(CONFIG_SHARP_PARAM) += sharpsl_param.o
>> obj-$(CONFIG_SHARP_SCOOP) += scoop.o
>> diff --git a/arch/arm/common/krait-l2-accessors.c b/arch/arm/common/krait-l2-accessors.c
>> new file mode 100644
>> index 0000000..9a97dda
>> --- /dev/null
>> +++ b/arch/arm/common/krait-l2-accessors.c
>> @@ -0,0 +1,48 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +// Copyright (c) 2018, The Linux Foundation. All rights reserved.
>> +
>> +#include <linux/spinlock.h>
>> +#include <linux/export.h>
>> +
>> +#include <asm/barrier.h>
>> +#include <asm/krait-l2-accessors.h>
>> +
>> +static DEFINE_RAW_SPINLOCK(krait_l2_lock);
>> +
>> +void krait_set_l2_indirect_reg(u32 addr, u32 val)
>> +{
>> + unsigned long flags;
>> +
>> + raw_spin_lock_irqsave(&krait_l2_lock, flags);
>> + /*
>> + * Select the L2 window by poking l2cpselr, then write to the window
>> + * via l2cpdr.
>> + */
>> + asm volatile ("mcr p15, 3, %0, c15, c0, 6 @ l2cpselr" : : "r" (addr));
>> + isb();
>> + asm volatile ("mcr p15, 3, %0, c15, c0, 7 @ l2cpdr" : : "r" (val));
>> + isb();
>> +
>> + raw_spin_unlock_irqrestore(&krait_l2_lock, flags);
>> +}
>> +EXPORT_SYMBOL(krait_set_l2_indirect_reg);
>> +
>> +u32 krait_get_l2_indirect_reg(u32 addr)
>> +{
>> + u32 val;
>> + unsigned long flags;
>> +
>> + raw_spin_lock_irqsave(&krait_l2_lock, flags);
>> + /*
>> + * Select the L2 window by poking l2cpselr, then read from the window
>> + * via l2cpdr.
>> + */
>> + asm volatile ("mcr p15, 3, %0, c15, c0, 6 @ l2cpselr" : : "r" (addr));
>> + isb();
>> + asm volatile ("mrc p15, 3, %0, c15, c0, 7 @ l2cpdr" : "=r" (val));
>> +
>> + raw_spin_unlock_irqrestore(&krait_l2_lock, flags);
>> +
>> + return val;
>> +}
>> +EXPORT_SYMBOL(krait_get_l2_indirect_reg);
>> diff --git a/arch/arm/include/asm/krait-l2-accessors.h b/arch/arm/include/asm/krait-l2-accessors.h
>> new file mode 100644
>> index 0000000..dd7c474
>> --- /dev/null
>> +++ b/arch/arm/include/asm/krait-l2-accessors.h
>> @@ -0,0 +1,10 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +// Copyright (c) 2018, The Linux Foundation. All rights reserved.
>> +
>> +#ifndef __ASMARM_KRAIT_L2_ACCESSORS_H
>> +#define __ASMARM_KRAIT_L2_ACCESSORS_H
>> +
>> +extern void krait_set_l2_indirect_reg(u32 addr, u32 val);
>> +extern u32 krait_get_l2_indirect_reg(u32 addr);
>> +
>> +#endif
>> --
>> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation
>>
--
"QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation
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