target/linux/ipq806x/patches/0164-ARM-Add-Krait-L2-register-accessor-functions.patch

   1 From d8bf5e13683e027c52476b89b874d50e5281c130 Mon Sep 17 00:00:00 2001
   2 From: Stephen Boyd <sboyd@codeaurora.org>
   3 Date: Fri, 18 Oct 2013 16:45:05 -0700
   4 Subject: [PATCH 164/182] ARM: Add Krait L2 register accessor functions
   5
   6 Krait CPUs have a handful of L2 cache controller registers that
   7 live behind a cp15 based indirection register. First you program
   8 the indirection register (l2cpselr) to point the L2 'window'
   9 register (l2cpdr) at what you want to read/write.  Then you
  10 read/write the 'window' register to do what you want. The
  11 l2cpselr register is not banked per-cpu so we must lock around
  12 accesses to it to prevent other CPUs from re-pointing l2cpdr
  13 underneath us.
  14
  15 Cc: Mark Rutland <mark.rutland@arm.com>
  16 Cc: Russell King <linux@arm.linux.org.uk>
  17 Cc: Courtney Cavin <courtney.cavin@sonymobile.com>
  18 Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
  19 ---
  20  arch/arm/common/Kconfig                   |    3 ++
  21  arch/arm/common/Makefile                  |    1 +
  22  arch/arm/common/krait-l2-accessors.c      |   58 +++++++++++++++++++++++++++++
  23  arch/arm/include/asm/krait-l2-accessors.h |   20 ++++++++++
  24  4 files changed, 82 insertions(+)
  25  create mode 100644 arch/arm/common/krait-l2-accessors.c
  26  create mode 100644 arch/arm/include/asm/krait-l2-accessors.h
  27
  28 diff --git a/arch/arm/common/Kconfig b/arch/arm/common/Kconfig
  29 index c3a4e9c..9da52dc 100644
  30 --- a/arch/arm/common/Kconfig
  31 +++ b/arch/arm/common/Kconfig
  32 @@ -9,6 +9,9 @@ config DMABOUNCE
  33         bool
  34         select ZONE_DMA
  35
  36 +config KRAIT_L2_ACCESSORS
  37 +       bool
  38 +
  39  config SHARP_LOCOMO
  40         bool
  41
  42 diff --git a/arch/arm/common/Makefile b/arch/arm/common/Makefile
  43 index 4bdc4162..2836f99 100644
  44 --- a/arch/arm/common/Makefile
  45 +++ b/arch/arm/common/Makefile
  46 @@ -7,6 +7,7 @@ obj-y                           += firmware.o
  47  obj-$(CONFIG_ICST)             += icst.o
  48  obj-$(CONFIG_SA1111)           += sa1111.o
  49  obj-$(CONFIG_DMABOUNCE)                += dmabounce.o
  50 +obj-$(CONFIG_KRAIT_L2_ACCESSORS) += krait-l2-accessors.o
  51  obj-$(CONFIG_SHARP_LOCOMO)     += locomo.o
  52  obj-$(CONFIG_SHARP_PARAM)      += sharpsl_param.o
  53  obj-$(CONFIG_SHARP_SCOOP)      += scoop.o
  54 diff --git a/arch/arm/common/krait-l2-accessors.c b/arch/arm/common/krait-l2-accessors.c
  55 new file mode 100644
  56 index 0000000..5d514bb
  57 --- /dev/null
  58 +++ b/arch/arm/common/krait-l2-accessors.c
  59 @@ -0,0 +1,58 @@
  60 +/*
  61 + * Copyright (c) 2011-2013, The Linux Foundation. All rights reserved.
  62 + *
  63 + * This program is free software; you can redistribute it and/or modify
  64 + * it under the terms of the GNU General Public License version 2 and
  65 + * only version 2 as published by the Free Software Foundation.
  66 + *
  67 + * This program is distributed in the hope that it will be useful,
  68 + * but WITHOUT ANY WARRANTY; without even the implied warranty of
  69 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  70 + * GNU General Public License for more details.
  71 + */
  72 +
  73 +#include <linux/spinlock.h>
  74 +#include <linux/export.h>
  75 +
  76 +#include <asm/barrier.h>
  77 +#include <asm/krait-l2-accessors.h>
  78 +
  79 +static DEFINE_RAW_SPINLOCK(krait_l2_lock);
  80 +
  81 +void krait_set_l2_indirect_reg(u32 addr, u32 val)
  82 +{
  83 +       unsigned long flags;
  84 +
  85 +       raw_spin_lock_irqsave(&krait_l2_lock, flags);
  86 +       /*
  87 +        * Select the L2 window by poking l2cpselr, then write to the window
  88 +        * via l2cpdr.
  89 +        */
  90 +       asm volatile ("mcr p15, 3, %0, c15, c0, 6 @ l2cpselr" : : "r" (addr));
  91 +       isb();
  92 +       asm volatile ("mcr p15, 3, %0, c15, c0, 7 @ l2cpdr" : : "r" (val));
  93 +       isb();
  94 +
  95 +       raw_spin_unlock_irqrestore(&krait_l2_lock, flags);
  96 +}
  97 +EXPORT_SYMBOL(krait_set_l2_indirect_reg);
  98 +
  99 +u32 krait_get_l2_indirect_reg(u32 addr)
 100 +{
 101 +       u32 val;
 102 +       unsigned long flags;
 103 +
 104 +       raw_spin_lock_irqsave(&krait_l2_lock, flags);
 105 +       /*
 106 +        * Select the L2 window by poking l2cpselr, then read from the window
 107 +        * via l2cpdr.
 108 +        */
 109 +       asm volatile ("mcr p15, 3, %0, c15, c0, 6 @ l2cpselr" : : "r" (addr));
 110 +       isb();
 111 +       asm volatile ("mrc p15, 3, %0, c15, c0, 7 @ l2cpdr" : "=r" (val));
 112 +
 113 +       raw_spin_unlock_irqrestore(&krait_l2_lock, flags);
 114 +
 115 +       return val;
 116 +}
 117 +EXPORT_SYMBOL(krait_get_l2_indirect_reg);
 118 diff --git a/arch/arm/include/asm/krait-l2-accessors.h b/arch/arm/include/asm/krait-l2-accessors.h
 119 new file mode 100644
 120 index 0000000..48fe552
 121 --- /dev/null
 122 +++ b/arch/arm/include/asm/krait-l2-accessors.h
 123 @@ -0,0 +1,20 @@
 124 +/*
 125 + * Copyright (c) 2011-2013, The Linux Foundation. All rights reserved.
 126 + *
 127 + * This program is free software; you can redistribute it and/or modify
 128 + * it under the terms of the GNU General Public License version 2 and
 129 + * only version 2 as published by the Free Software Foundation.
 130 + *
 131 + * This program is distributed in the hope that it will be useful,
 132 + * but WITHOUT ANY WARRANTY; without even the implied warranty of
 133 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 134 + * GNU General Public License for more details.
 135 + */
 136 +
 137 +#ifndef __ASMARM_KRAIT_L2_ACCESSORS_H
 138 +#define __ASMARM_KRAIT_L2_ACCESSORS_H
 139 +
 140 +extern void krait_set_l2_indirect_reg(u32 addr, u32 val);
 141 +extern u32 krait_get_l2_indirect_reg(u32 addr);
 142 +
 143 +#endif
 144 --
 145 1.7.10.4
 146