target/linux/ipq806x/patches-4.19/0034-0001-ARM-Add-Krait-L2-register-accessor-functions.patch

   1 From 36d68f64c411e09788687d5919886aadeb92adca Mon Sep 17 00:00:00 2001
   2 From: Stephen Boyd <sboyd@codeaurora.org>
   3 Date: Tue, 14 Aug 2018 17:42:20 +0530
   4 Subject: [PATCH 01/12] 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 Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org>
  18 Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
  19 Signed-off-by: Sricharan R <sricharan@codeaurora.org>
  20 Tested-by: Craig Tatlor <ctatlor97@gmail.com>
  21 Signed-off-by: Stephen Boyd <sboyd@kernel.org>
  22 ---
  23  arch/arm/common/Kconfig                   |  3 ++
  24  arch/arm/common/Makefile                  |  1 +
  25  arch/arm/common/krait-l2-accessors.c      | 48 +++++++++++++++++++++++
  26  arch/arm/include/asm/krait-l2-accessors.h |  9 +++++
  27  4 files changed, 61 insertions(+)
  28  create mode 100644 arch/arm/common/krait-l2-accessors.c
  29  create mode 100644 arch/arm/include/asm/krait-l2-accessors.h
  30
  31 --- a/arch/arm/common/Kconfig
  32 +++ b/arch/arm/common/Kconfig
  33 @@ -7,6 +7,9 @@ config DMABOUNCE
  34         bool
  35         select ZONE_DMA
  36
  37 +config KRAIT_L2_ACCESSORS
  38 +       bool
  39 +
  40  config SHARP_LOCOMO
  41         bool
  42
  43 --- a/arch/arm/common/Makefile
  44 +++ b/arch/arm/common/Makefile
  45 @@ -7,6 +7,7 @@ obj-y                           += firmware.o
  46
  47  obj-$(CONFIG_SA1111)           += sa1111.o
  48  obj-$(CONFIG_DMABOUNCE)                += dmabounce.o
  49 +obj-$(CONFIG_KRAIT_L2_ACCESSORS) += krait-l2-accessors.o
  50  obj-$(CONFIG_SHARP_LOCOMO)     += locomo.o
  51  obj-$(CONFIG_SHARP_PARAM)      += sharpsl_param.o
  52  obj-$(CONFIG_SHARP_SCOOP)      += scoop.o
  53 --- /dev/null
  54 +++ b/arch/arm/common/krait-l2-accessors.c
  55 @@ -0,0 +1,48 @@
  56 +// SPDX-License-Identifier: GPL-2.0
  57 +// Copyright (c) 2018, The Linux Foundation. All rights reserved.
  58 +
  59 +#include <linux/spinlock.h>
  60 +#include <linux/export.h>
  61 +
  62 +#include <asm/barrier.h>
  63 +#include <asm/krait-l2-accessors.h>
  64 +
  65 +static DEFINE_RAW_SPINLOCK(krait_l2_lock);
  66 +
  67 +void krait_set_l2_indirect_reg(u32 addr, u32 val)
  68 +{
  69 +       unsigned long flags;
  70 +
  71 +       raw_spin_lock_irqsave(&krait_l2_lock, flags);
  72 +       /*
  73 +        * Select the L2 window by poking l2cpselr, then write to the window
  74 +        * via l2cpdr.
  75 +        */
  76 +       asm volatile ("mcr p15, 3, %0, c15, c0, 6 @ l2cpselr" : : "r" (addr));
  77 +       isb();
  78 +       asm volatile ("mcr p15, 3, %0, c15, c0, 7 @ l2cpdr" : : "r" (val));
  79 +       isb();
  80 +
  81 +       raw_spin_unlock_irqrestore(&krait_l2_lock, flags);
  82 +}
  83 +EXPORT_SYMBOL(krait_set_l2_indirect_reg);
  84 +
  85 +u32 krait_get_l2_indirect_reg(u32 addr)
  86 +{
  87 +       u32 val;
  88 +       unsigned long flags;
  89 +
  90 +       raw_spin_lock_irqsave(&krait_l2_lock, flags);
  91 +       /*
  92 +        * Select the L2 window by poking l2cpselr, then read from the window
  93 +        * via l2cpdr.
  94 +        */
  95 +       asm volatile ("mcr p15, 3, %0, c15, c0, 6 @ l2cpselr" : : "r" (addr));
  96 +       isb();
  97 +       asm volatile ("mrc p15, 3, %0, c15, c0, 7 @ l2cpdr" : "=r" (val));
  98 +
  99 +       raw_spin_unlock_irqrestore(&krait_l2_lock, flags);
 100 +
 101 +       return val;
 102 +}
 103 +EXPORT_SYMBOL(krait_get_l2_indirect_reg);
 104 --- /dev/null
 105 +++ b/arch/arm/include/asm/krait-l2-accessors.h
 106 @@ -0,0 +1,9 @@
 107 +/* SPDX-License-Identifier: GPL-2.0 */
 108 +
 109 +#ifndef __ASMARM_KRAIT_L2_ACCESSORS_H
 110 +#define __ASMARM_KRAIT_L2_ACCESSORS_H
 111 +
 112 +extern void krait_set_l2_indirect_reg(u32 addr, u32 val);
 113 +extern u32 krait_get_l2_indirect_reg(u32 addr);
 114 +
 115 +#endif