target/linux/ipq806x/patches-4.14/0034-ARM-Add-Krait-L2-register-accessor-functions.patch

   1 From patchwork Fri Dec  8 09:42:19 2017
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   5 Subject: [v4,01/12] ARM: Add Krait L2 register accessor functions
   6 From: Sricharan R <sricharan@codeaurora.org>
   7 X-Patchwork-Id: 10102101
   8 Message-Id: <1512726150-7204-2-git-send-email-sricharan@codeaurora.org>
   9 To: mturquette@baylibre.com, sboyd@codeaurora.org,
  10  devicetree@vger.kernel.org, linux-pm@vger.kernel.org,
  11  linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org,
  12  viresh.kumar@linaro.org, linux-arm-kernel@lists.infradead.org
  13 Cc: sricharan@codeaurora.org, Mark Rutland <mark.rutland@arm.com>,
  14  Russell King <linux@arm.linux.org.uk>,
  15  Courtney Cavin <courtney.cavin@sonymobile.com>
  16 Date: Fri,  8 Dec 2017 15:12:19 +0530
  17
  18 From: Stephen Boyd <sboyd@codeaurora.org>
  19
  20 Krait CPUs have a handful of L2 cache controller registers that
  21 live behind a cp15 based indirection register. First you program
  22 the indirection register (l2cpselr) to point the L2 'window'
  23 register (l2cpdr) at what you want to read/write.  Then you
  24 read/write the 'window' register to do what you want. The
  25 l2cpselr register is not banked per-cpu so we must lock around
  26 accesses to it to prevent other CPUs from re-pointing l2cpdr
  27 underneath us.
  28
  29 Cc: Mark Rutland <mark.rutland@arm.com>
  30 Cc: Russell King <linux@arm.linux.org.uk>
  31 Cc: Courtney Cavin <courtney.cavin@sonymobile.com>
  32 Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
  33 ---
  34  arch/arm/common/Kconfig                   |  3 ++
  35  arch/arm/common/Makefile                  |  1 +
  36  arch/arm/common/krait-l2-accessors.c      | 58 +++++++++++++++++++++++++++++++
  37  arch/arm/include/asm/krait-l2-accessors.h | 20 +++++++++++
  38  4 files changed, 82 insertions(+)
  39  create mode 100644 arch/arm/common/krait-l2-accessors.c
  40  create mode 100644 arch/arm/include/asm/krait-l2-accessors.h
  41
  42 --- a/arch/arm/common/Kconfig
  43 +++ b/arch/arm/common/Kconfig
  44 @@ -7,6 +7,9 @@ config DMABOUNCE
  45         bool
  46         select ZONE_DMA
  47
  48 +config KRAIT_L2_ACCESSORS
  49 +       bool
  50 +
  51  config SHARP_LOCOMO
  52         bool
  53
  54 --- a/arch/arm/common/Makefile
  55 +++ b/arch/arm/common/Makefile
  56 @@ -7,6 +7,7 @@ obj-y                           += firmware.o
  57
  58  obj-$(CONFIG_SA1111)           += sa1111.o
  59  obj-$(CONFIG_DMABOUNCE)                += dmabounce.o
  60 +obj-$(CONFIG_KRAIT_L2_ACCESSORS) += krait-l2-accessors.o
  61  obj-$(CONFIG_SHARP_LOCOMO)     += locomo.o
  62  obj-$(CONFIG_SHARP_PARAM)      += sharpsl_param.o
  63  obj-$(CONFIG_SHARP_SCOOP)      += scoop.o
  64 --- /dev/null
  65 +++ b/arch/arm/common/krait-l2-accessors.c
  66 @@ -0,0 +1,58 @@
  67 +/*
  68 + * Copyright (c) 2011-2013, The Linux Foundation. All rights reserved.
  69 + *
  70 + * This program is free software; you can redistribute it and/or modify
  71 + * it under the terms of the GNU General Public License version 2 and
  72 + * only version 2 as published by the Free Software Foundation.
  73 + *
  74 + * This program is distributed in the hope that it will be useful,
  75 + * but WITHOUT ANY WARRANTY; without even the implied warranty of
  76 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  77 + * GNU General Public License for more details.
  78 + */
  79 +
  80 +#include <linux/spinlock.h>
  81 +#include <linux/export.h>
  82 +
  83 +#include <asm/barrier.h>
  84 +#include <asm/krait-l2-accessors.h>
  85 +
  86 +static DEFINE_RAW_SPINLOCK(krait_l2_lock);
  87 +
  88 +void krait_set_l2_indirect_reg(u32 addr, u32 val)
  89 +{
  90 +       unsigned long flags;
  91 +
  92 +       raw_spin_lock_irqsave(&krait_l2_lock, flags);
  93 +       /*
  94 +        * Select the L2 window by poking l2cpselr, then write to the window
  95 +        * via l2cpdr.
  96 +        */
  97 +       asm volatile ("mcr p15, 3, %0, c15, c0, 6 @ l2cpselr" : : "r" (addr));
  98 +       isb();
  99 +       asm volatile ("mcr p15, 3, %0, c15, c0, 7 @ l2cpdr" : : "r" (val));
 100 +       isb();
 101 +
 102 +       raw_spin_unlock_irqrestore(&krait_l2_lock, flags);
 103 +}
 104 +EXPORT_SYMBOL(krait_set_l2_indirect_reg);
 105 +
 106 +u32 krait_get_l2_indirect_reg(u32 addr)
 107 +{
 108 +       u32 val;
 109 +       unsigned long flags;
 110 +
 111 +       raw_spin_lock_irqsave(&krait_l2_lock, flags);
 112 +       /*
 113 +        * Select the L2 window by poking l2cpselr, then read from the window
 114 +        * via l2cpdr.
 115 +        */
 116 +       asm volatile ("mcr p15, 3, %0, c15, c0, 6 @ l2cpselr" : : "r" (addr));
 117 +       isb();
 118 +       asm volatile ("mrc p15, 3, %0, c15, c0, 7 @ l2cpdr" : "=r" (val));
 119 +
 120 +       raw_spin_unlock_irqrestore(&krait_l2_lock, flags);
 121 +
 122 +       return val;
 123 +}
 124 +EXPORT_SYMBOL(krait_get_l2_indirect_reg);
 125 --- /dev/null
 126 +++ b/arch/arm/include/asm/krait-l2-accessors.h
 127 @@ -0,0 +1,20 @@
 128 +/*
 129 + * Copyright (c) 2011-2013, The Linux Foundation. All rights reserved.
 130 + *
 131 + * This program is free software; you can redistribute it and/or modify
 132 + * it under the terms of the GNU General Public License version 2 and
 133 + * only version 2 as published by the Free Software Foundation.
 134 + *
 135 + * This program is distributed in the hope that it will be useful,
 136 + * but WITHOUT ANY WARRANTY; without even the implied warranty of
 137 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 138 + * GNU General Public License for more details.
 139 + */
 140 +
 141 +#ifndef __ASMARM_KRAIT_L2_ACCESSORS_H
 142 +#define __ASMARM_KRAIT_L2_ACCESSORS_H
 143 +
 144 +extern void krait_set_l2_indirect_reg(u32 addr, u32 val);
 145 +extern u32 krait_get_l2_indirect_reg(u32 addr);
 146 +
 147 +#endif