target/linux/ipq806x/patches-4.9/0034-ARM-Add-Krait-L2-register-accessor-functions.patch

   1 From 1d6b12f73c98ecf252743936a53242356cc50a34 Mon Sep 17 00:00:00 2001
   2 From: Stephen Boyd <sboyd@codeaurora.org>
   3 Date: Fri, 20 Mar 2015 23:45:20 -0700
   4 Subject: [PATCH 34/69] 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 --- a/arch/arm/common/Kconfig
  29 +++ b/arch/arm/common/Kconfig
  30 @@ -9,6 +9,9 @@ config DMABOUNCE
  31         bool
  32         select ZONE_DMA
  33
  34 +config KRAIT_L2_ACCESSORS
  35 +       bool
  36 +
  37  config SHARP_LOCOMO
  38         bool
  39
  40 --- a/arch/arm/common/Makefile
  41 +++ b/arch/arm/common/Makefile
  42 @@ -7,6 +7,7 @@ obj-y                           += firmware.o
  43  obj-$(CONFIG_ICST)             += icst.o
  44  obj-$(CONFIG_SA1111)           += sa1111.o
  45  obj-$(CONFIG_DMABOUNCE)                += dmabounce.o
  46 +obj-$(CONFIG_KRAIT_L2_ACCESSORS) += krait-l2-accessors.o
  47  obj-$(CONFIG_SHARP_LOCOMO)     += locomo.o
  48  obj-$(CONFIG_SHARP_PARAM)      += sharpsl_param.o
  49  obj-$(CONFIG_SHARP_SCOOP)      += scoop.o
  50 --- /dev/null
  51 +++ b/arch/arm/common/krait-l2-accessors.c
  52 @@ -0,0 +1,58 @@
  53 +/*
  54 + * Copyright (c) 2011-2013, The Linux Foundation. All rights reserved.
  55 + *
  56 + * This program is free software; you can redistribute it and/or modify
  57 + * it under the terms of the GNU General Public License version 2 and
  58 + * only version 2 as published by the Free Software Foundation.
  59 + *
  60 + * This program is distributed in the hope that it will be useful,
  61 + * but WITHOUT ANY WARRANTY; without even the implied warranty of
  62 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  63 + * GNU General Public License for more details.
  64 + */
  65 +
  66 +#include <linux/spinlock.h>
  67 +#include <linux/export.h>
  68 +
  69 +#include <asm/barrier.h>
  70 +#include <asm/krait-l2-accessors.h>
  71 +
  72 +static DEFINE_RAW_SPINLOCK(krait_l2_lock);
  73 +
  74 +void krait_set_l2_indirect_reg(u32 addr, u32 val)
  75 +{
  76 +       unsigned long flags;
  77 +
  78 +       raw_spin_lock_irqsave(&krait_l2_lock, flags);
  79 +       /*
  80 +        * Select the L2 window by poking l2cpselr, then write to the window
  81 +        * via l2cpdr.
  82 +        */
  83 +       asm volatile ("mcr p15, 3, %0, c15, c0, 6 @ l2cpselr" : : "r" (addr));
  84 +       isb();
  85 +       asm volatile ("mcr p15, 3, %0, c15, c0, 7 @ l2cpdr" : : "r" (val));
  86 +       isb();
  87 +
  88 +       raw_spin_unlock_irqrestore(&krait_l2_lock, flags);
  89 +}
  90 +EXPORT_SYMBOL(krait_set_l2_indirect_reg);
  91 +
  92 +u32 krait_get_l2_indirect_reg(u32 addr)
  93 +{
  94 +       u32 val;
  95 +       unsigned long flags;
  96 +
  97 +       raw_spin_lock_irqsave(&krait_l2_lock, flags);
  98 +       /*
  99 +        * Select the L2 window by poking l2cpselr, then read from the window
 100 +        * via l2cpdr.
 101 +        */
 102 +       asm volatile ("mcr p15, 3, %0, c15, c0, 6 @ l2cpselr" : : "r" (addr));
 103 +       isb();
 104 +       asm volatile ("mrc p15, 3, %0, c15, c0, 7 @ l2cpdr" : "=r" (val));
 105 +
 106 +       raw_spin_unlock_irqrestore(&krait_l2_lock, flags);
 107 +
 108 +       return val;
 109 +}
 110 +EXPORT_SYMBOL(krait_get_l2_indirect_reg);
 111 --- /dev/null
 112 +++ b/arch/arm/include/asm/krait-l2-accessors.h
 113 @@ -0,0 +1,20 @@
 114 +/*
 115 + * Copyright (c) 2011-2013, The Linux Foundation. All rights reserved.
 116 + *
 117 + * This program is free software; you can redistribute it and/or modify
 118 + * it under the terms of the GNU General Public License version 2 and
 119 + * only version 2 as published by the Free Software Foundation.
 120 + *
 121 + * This program is distributed in the hope that it will be useful,
 122 + * but WITHOUT ANY WARRANTY; without even the implied warranty of
 123 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 124 + * GNU General Public License for more details.
 125 + */
 126 +
 127 +#ifndef __ASMARM_KRAIT_L2_ACCESSORS_H
 128 +#define __ASMARM_KRAIT_L2_ACCESSORS_H
 129 +
 130 +extern void krait_set_l2_indirect_reg(u32 addr, u32 val);
 131 +extern u32 krait_get_l2_indirect_reg(u32 addr);
 132 +
 133 +#endif