cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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sprd_hwspinlock.c (4159B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * Spreadtrum hardware spinlock driver
      4 * Copyright (C) 2017 Spreadtrum  - http://www.spreadtrum.com
      5 */
      6
      7#include <linux/clk.h>
      8#include <linux/delay.h>
      9#include <linux/device.h>
     10#include <linux/hwspinlock.h>
     11#include <linux/io.h>
     12#include <linux/kernel.h>
     13#include <linux/module.h>
     14#include <linux/of.h>
     15#include <linux/of_device.h>
     16#include <linux/platform_device.h>
     17
     18#include "hwspinlock_internal.h"
     19
     20/* hwspinlock registers definition */
     21#define HWSPINLOCK_RECCTRL		0x4
     22#define HWSPINLOCK_MASTERID(_X_)	(0x80 + 0x4 * (_X_))
     23#define HWSPINLOCK_TOKEN(_X_)		(0x800 + 0x4 * (_X_))
     24
     25/* unlocked value */
     26#define HWSPINLOCK_NOTTAKEN		0x55aa10c5
     27/* bits definition of RECCTRL reg */
     28#define HWSPINLOCK_USER_BITS		0x1
     29
     30/* hwspinlock number */
     31#define SPRD_HWLOCKS_NUM		32
     32
     33struct sprd_hwspinlock_dev {
     34	void __iomem *base;
     35	struct clk *clk;
     36	struct hwspinlock_device bank;
     37};
     38
     39/* try to lock the hardware spinlock */
     40static int sprd_hwspinlock_trylock(struct hwspinlock *lock)
     41{
     42	struct sprd_hwspinlock_dev *sprd_hwlock =
     43		dev_get_drvdata(lock->bank->dev);
     44	void __iomem *addr = lock->priv;
     45	int user_id, lock_id;
     46
     47	if (!readl(addr))
     48		return 1;
     49
     50	lock_id = hwlock_to_id(lock);
     51	/* get the hardware spinlock master/user id */
     52	user_id = readl(sprd_hwlock->base + HWSPINLOCK_MASTERID(lock_id));
     53	dev_warn(sprd_hwlock->bank.dev,
     54		 "hwspinlock [%d] lock failed and master/user id = %d!\n",
     55		 lock_id, user_id);
     56	return 0;
     57}
     58
     59/* unlock the hardware spinlock */
     60static void sprd_hwspinlock_unlock(struct hwspinlock *lock)
     61{
     62	void __iomem *lock_addr = lock->priv;
     63
     64	writel(HWSPINLOCK_NOTTAKEN, lock_addr);
     65}
     66
     67/* The specs recommended below number as the retry delay time */
     68static void sprd_hwspinlock_relax(struct hwspinlock *lock)
     69{
     70	ndelay(10);
     71}
     72
     73static const struct hwspinlock_ops sprd_hwspinlock_ops = {
     74	.trylock = sprd_hwspinlock_trylock,
     75	.unlock = sprd_hwspinlock_unlock,
     76	.relax = sprd_hwspinlock_relax,
     77};
     78
     79static void sprd_hwspinlock_disable(void *data)
     80{
     81	struct sprd_hwspinlock_dev *sprd_hwlock = data;
     82
     83	clk_disable_unprepare(sprd_hwlock->clk);
     84}
     85
     86static int sprd_hwspinlock_probe(struct platform_device *pdev)
     87{
     88	struct sprd_hwspinlock_dev *sprd_hwlock;
     89	struct hwspinlock *lock;
     90	int i, ret;
     91
     92	if (!pdev->dev.of_node)
     93		return -ENODEV;
     94
     95	sprd_hwlock = devm_kzalloc(&pdev->dev,
     96				   struct_size(sprd_hwlock, bank.lock, SPRD_HWLOCKS_NUM),
     97				   GFP_KERNEL);
     98	if (!sprd_hwlock)
     99		return -ENOMEM;
    100
    101	sprd_hwlock->base = devm_platform_ioremap_resource(pdev, 0);
    102	if (IS_ERR(sprd_hwlock->base))
    103		return PTR_ERR(sprd_hwlock->base);
    104
    105	sprd_hwlock->clk = devm_clk_get(&pdev->dev, "enable");
    106	if (IS_ERR(sprd_hwlock->clk)) {
    107		dev_err(&pdev->dev, "get hwspinlock clock failed!\n");
    108		return PTR_ERR(sprd_hwlock->clk);
    109	}
    110
    111	ret = clk_prepare_enable(sprd_hwlock->clk);
    112	if (ret)
    113		return ret;
    114
    115	ret = devm_add_action_or_reset(&pdev->dev, sprd_hwspinlock_disable,
    116				       sprd_hwlock);
    117	if (ret) {
    118		dev_err(&pdev->dev,
    119			"Failed to add hwspinlock disable action\n");
    120		return ret;
    121	}
    122
    123	/* set the hwspinlock to record user id to identify subsystems */
    124	writel(HWSPINLOCK_USER_BITS, sprd_hwlock->base + HWSPINLOCK_RECCTRL);
    125
    126	for (i = 0; i < SPRD_HWLOCKS_NUM; i++) {
    127		lock = &sprd_hwlock->bank.lock[i];
    128		lock->priv = sprd_hwlock->base + HWSPINLOCK_TOKEN(i);
    129	}
    130
    131	platform_set_drvdata(pdev, sprd_hwlock);
    132
    133	return devm_hwspin_lock_register(&pdev->dev, &sprd_hwlock->bank,
    134					 &sprd_hwspinlock_ops, 0,
    135					 SPRD_HWLOCKS_NUM);
    136}
    137
    138static const struct of_device_id sprd_hwspinlock_of_match[] = {
    139	{ .compatible = "sprd,hwspinlock-r3p0", },
    140	{ /* sentinel */ }
    141};
    142MODULE_DEVICE_TABLE(of, sprd_hwspinlock_of_match);
    143
    144static struct platform_driver sprd_hwspinlock_driver = {
    145	.probe = sprd_hwspinlock_probe,
    146	.driver = {
    147		.name = "sprd_hwspinlock",
    148		.of_match_table = sprd_hwspinlock_of_match,
    149	},
    150};
    151module_platform_driver(sprd_hwspinlock_driver);
    152
    153MODULE_LICENSE("GPL v2");
    154MODULE_DESCRIPTION("Hardware spinlock driver for Spreadtrum");
    155MODULE_AUTHOR("Baolin Wang <baolin.wang@spreadtrum.com>");
    156MODULE_AUTHOR("Lanqing Liu <lanqing.liu@spreadtrum.com>");
    157MODULE_AUTHOR("Long Cheng <aiden.cheng@spreadtrum.com>");