target/linux/ipq806x/patches-4.4/133-ARM-Add-Krait-L2-register-accessor-functions.patch

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   4 Subject: [v3,01/13] ARM: Add Krait L2 register accessor functions
   5 From: Stephen Boyd <sboyd@codeaurora.org>
   6 X-Patchwork-Id: 6063051
   7 Message-Id: <1426920332-9340-2-git-send-email-sboyd@codeaurora.org>
   8 To: Mike Turquette <mturquette@linaro.org>, Stephen Boyd <sboyd@codeaurora.org>
   9 Cc: linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org,
  10         linux-pm@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
  11         Viresh Kumar <viresh.kumar@linaro.org>,
  12         Mark Rutland <mark.rutland@arm.com>, Russell King <linux@arm.linux.org.uk>,
  13         Courtney Cavin <courtney.cavin@sonymobile.com>
  14 Date: Fri, 20 Mar 2015 23:45:20 -0700
  15
  16 Krait CPUs have a handful of L2 cache controller registers that
  17 live behind a cp15 based indirection register. First you program
  18 the indirection register (l2cpselr) to point the L2 'window'
  19 register (l2cpdr) at what you want to read/write.  Then you
  20 read/write the 'window' register to do what you want. The
  21 l2cpselr register is not banked per-cpu so we must lock around
  22 accesses to it to prevent other CPUs from re-pointing l2cpdr
  23 underneath us.
  24
  25 Cc: Mark Rutland <mark.rutland@arm.com>
  26 Cc: Russell King <linux@arm.linux.org.uk>
  27 Cc: Courtney Cavin <courtney.cavin@sonymobile.com>
  28 Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
  29
  30 ---
  31 arch/arm/common/Kconfig                   |  3 ++
  32  arch/arm/common/Makefile                  |  1 +
  33  arch/arm/common/krait-l2-accessors.c      | 58 +++++++++++++++++++++++++++++++
  34  arch/arm/include/asm/krait-l2-accessors.h | 20 +++++++++++
  35  4 files changed, 82 insertions(+)
  36  create mode 100644 arch/arm/common/krait-l2-accessors.c
  37  create mode 100644 arch/arm/include/asm/krait-l2-accessors.h
  38
  39 --- a/arch/arm/common/Kconfig
  40 +++ b/arch/arm/common/Kconfig
  41 @@ -9,6 +9,9 @@
  42         bool
  43         select ZONE_DMA
  44
  45 +config KRAIT_L2_ACCESSORS
  46 +       bool
  47 +
  48  config SHARP_LOCOMO
  49         bool
  50
  51 --- a/arch/arm/common/Makefile
  52 +++ b/arch/arm/common/Makefile
  53 @@ -7,6 +7,7 @@
  54  obj-$(CONFIG_ICST)             += icst.o
  55  obj-$(CONFIG_SA1111)           += sa1111.o
  56  obj-$(CONFIG_DMABOUNCE)                += dmabounce.o
  57 +obj-$(CONFIG_KRAIT_L2_ACCESSORS) += krait-l2-accessors.o
  58  obj-$(CONFIG_SHARP_LOCOMO)     += locomo.o
  59  obj-$(CONFIG_SHARP_PARAM)      += sharpsl_param.o
  60  obj-$(CONFIG_SHARP_SCOOP)      += scoop.o
  61 --- /dev/null
  62 +++ b/arch/arm/common/krait-l2-accessors.c
  63 @@ -0,0 +1,58 @@
  64 +/*
  65 + * Copyright (c) 2011-2013, The Linux Foundation. All rights reserved.
  66 + *
  67 + * This program is free software; you can redistribute it and/or modify
  68 + * it under the terms of the GNU General Public License version 2 and
  69 + * only version 2 as published by the Free Software Foundation.
  70 + *
  71 + * This program is distributed in the hope that it will be useful,
  72 + * but WITHOUT ANY WARRANTY; without even the implied warranty of
  73 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  74 + * GNU General Public License for more details.
  75 + */
  76 +
  77 +#include <linux/spinlock.h>
  78 +#include <linux/export.h>
  79 +
  80 +#include <asm/barrier.h>
  81 +#include <asm/krait-l2-accessors.h>
  82 +
  83 +static DEFINE_RAW_SPINLOCK(krait_l2_lock);
  84 +
  85 +void krait_set_l2_indirect_reg(u32 addr, u32 val)
  86 +{
  87 +       unsigned long flags;
  88 +
  89 +       raw_spin_lock_irqsave(&krait_l2_lock, flags);
  90 +       /*
  91 +        * Select the L2 window by poking l2cpselr, then write to the window
  92 +        * via l2cpdr.
  93 +        */
  94 +       asm volatile ("mcr p15, 3, %0, c15, c0, 6 @ l2cpselr" : : "r" (addr));
  95 +       isb();
  96 +       asm volatile ("mcr p15, 3, %0, c15, c0, 7 @ l2cpdr" : : "r" (val));
  97 +       isb();
  98 +
  99 +       raw_spin_unlock_irqrestore(&krait_l2_lock, flags);
 100 +}
 101 +EXPORT_SYMBOL(krait_set_l2_indirect_reg);
 102 +
 103 +u32 krait_get_l2_indirect_reg(u32 addr)
 104 +{
 105 +       u32 val;
 106 +       unsigned long flags;
 107 +
 108 +       raw_spin_lock_irqsave(&krait_l2_lock, flags);
 109 +       /*
 110 +        * Select the L2 window by poking l2cpselr, then read from the window
 111 +        * via l2cpdr.
 112 +        */
 113 +       asm volatile ("mcr p15, 3, %0, c15, c0, 6 @ l2cpselr" : : "r" (addr));
 114 +       isb();
 115 +       asm volatile ("mrc p15, 3, %0, c15, c0, 7 @ l2cpdr" : "=r" (val));
 116 +
 117 +       raw_spin_unlock_irqrestore(&krait_l2_lock, flags);
 118 +
 119 +       return val;
 120 +}
 121 +EXPORT_SYMBOL(krait_get_l2_indirect_reg);
 122 --- /dev/null
 123 +++ b/arch/arm/include/asm/krait-l2-accessors.h
 124 @@ -0,0 +1,20 @@
 125 +/*
 126 + * Copyright (c) 2011-2013, The Linux Foundation. All rights reserved.
 127 + *
 128 + * This program is free software; you can redistribute it and/or modify
 129 + * it under the terms of the GNU General Public License version 2 and
 130 + * only version 2 as published by the Free Software Foundation.
 131 + *
 132 + * This program is distributed in the hope that it will be useful,
 133 + * but WITHOUT ANY WARRANTY; without even the implied warranty of
 134 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 135 + * GNU General Public License for more details.
 136 + */
 137 +
 138 +#ifndef __ASMARM_KRAIT_L2_ACCESSORS_H
 139 +#define __ASMARM_KRAIT_L2_ACCESSORS_H
 140 +
 141 +extern void krait_set_l2_indirect_reg(u32 addr, u32 val);
 142 +extern u32 krait_get_l2_indirect_reg(u32 addr);
 143 +
 144 +#endif