LXR linux/arch/arm/common/krait-l2-accessors.c

   1// SPDX-License-Identifier: GPL-2.0
   2// Copyright (c) 2018, The Linux Foundation. All rights reserved.
   3
   4#include <linux/spinlock.h>
   5#include <linux/export.h>
   6
   7#include <asm/barrier.h>
   8#include <asm/krait-l2-accessors.h>
   9
  10static DEFINE_RAW_SPINLOCK(krait_l2_lock);
  11
  12void krait_set_l2_indirect_reg(u32 addr, u32 val)
  13{
  14        unsigned long flags;
  15
  16        raw_spin_lock_irqsave(&krait_l2_lock, flags);
  17        /*
  18         * Select the L2 window by poking l2cpselr, then write to the window
  19         * via l2cpdr.
  20         */
  21        asm volatile ("mcr p15, 3, %0, c15, c0, 6 @ l2cpselr" : : "r" (addr));
  22        isb();
  23        asm volatile ("mcr p15, 3, %0, c15, c0, 7 @ l2cpdr" : : "r" (val));
  24        isb();
  25
  26        raw_spin_unlock_irqrestore(&krait_l2_lock, flags);
  27}
  28EXPORT_SYMBOL(krait_set_l2_indirect_reg);
  29
  30u32 krait_get_l2_indirect_reg(u32 addr)
  31{
  32        u32 val;
  33        unsigned long flags;
  34
  35        raw_spin_lock_irqsave(&krait_l2_lock, flags);
  36        /*
  37         * Select the L2 window by poking l2cpselr, then read from the window
  38         * via l2cpdr.
  39         */
  40        asm volatile ("mcr p15, 3, %0, c15, c0, 6 @ l2cpselr" : : "r" (addr));
  41        isb();
  42        asm volatile ("mrc p15, 3, %0, c15, c0, 7 @ l2cpdr" : "=r" (val));
  43
  44        raw_spin_unlock_irqrestore(&krait_l2_lock, flags);
  45
  46        return val;
  47}
  48EXPORT_SYMBOL(krait_get_l2_indirect_reg);
  49