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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omap-iommu.c (2997B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * OMAP IOMMU quirks for various TI SoCs
      4 *
      5 * Copyright (C) 2015-2019 Texas Instruments Incorporated - https://www.ti.com/
      6 *      Suman Anna <s-anna@ti.com>
      7 */
      8
      9#include <linux/platform_device.h>
     10#include <linux/err.h>
     11#include <linux/clk.h>
     12#include <linux/list.h>
     13
     14#include "clockdomain.h"
     15#include "powerdomain.h"
     16#include "common.h"
     17
     18struct pwrdm_link {
     19	struct device *dev;
     20	struct powerdomain *pwrdm;
     21	struct list_head node;
     22};
     23
     24static DEFINE_SPINLOCK(iommu_lock);
     25static struct clockdomain *emu_clkdm;
     26static atomic_t emu_count;
     27
     28static void omap_iommu_dra7_emu_swsup_config(struct platform_device *pdev,
     29					     bool enable)
     30{
     31	struct device_node *np = pdev->dev.of_node;
     32	unsigned long flags;
     33
     34	if (!of_device_is_compatible(np, "ti,dra7-dsp-iommu"))
     35		return;
     36
     37	if (!emu_clkdm) {
     38		emu_clkdm = clkdm_lookup("emu_clkdm");
     39		if (WARN_ON_ONCE(!emu_clkdm))
     40			return;
     41	}
     42
     43	spin_lock_irqsave(&iommu_lock, flags);
     44
     45	if (enable && (atomic_inc_return(&emu_count) == 1))
     46		clkdm_deny_idle(emu_clkdm);
     47	else if (!enable && (atomic_dec_return(&emu_count) == 0))
     48		clkdm_allow_idle(emu_clkdm);
     49
     50	spin_unlock_irqrestore(&iommu_lock, flags);
     51}
     52
     53static struct powerdomain *_get_pwrdm(struct device *dev)
     54{
     55	struct clk *clk;
     56	struct clk_hw_omap *hwclk;
     57	struct clockdomain *clkdm;
     58	struct powerdomain *pwrdm = NULL;
     59	struct pwrdm_link *entry;
     60	unsigned long flags;
     61	static LIST_HEAD(cache);
     62
     63	spin_lock_irqsave(&iommu_lock, flags);
     64
     65	list_for_each_entry(entry, &cache, node) {
     66		if (entry->dev == dev) {
     67			pwrdm = entry->pwrdm;
     68			break;
     69		}
     70	}
     71
     72	spin_unlock_irqrestore(&iommu_lock, flags);
     73
     74	if (pwrdm)
     75		return pwrdm;
     76
     77	clk = of_clk_get(dev->of_node->parent, 0);
     78	if (IS_ERR(clk)) {
     79		dev_err(dev, "no fck found\n");
     80		return NULL;
     81	}
     82
     83	hwclk = to_clk_hw_omap(__clk_get_hw(clk));
     84	clk_put(clk);
     85	if (!hwclk || !hwclk->clkdm_name) {
     86		dev_err(dev, "no hwclk data\n");
     87		return NULL;
     88	}
     89
     90	clkdm = clkdm_lookup(hwclk->clkdm_name);
     91	if (!clkdm) {
     92		dev_err(dev, "clkdm not found: %s\n", hwclk->clkdm_name);
     93		return NULL;
     94	}
     95
     96	pwrdm = clkdm_get_pwrdm(clkdm);
     97	if (!pwrdm) {
     98		dev_err(dev, "pwrdm not found: %s\n", clkdm->name);
     99		return NULL;
    100	}
    101
    102	entry = kmalloc(sizeof(*entry), GFP_KERNEL);
    103	if (entry) {
    104		entry->dev = dev;
    105		entry->pwrdm = pwrdm;
    106		spin_lock_irqsave(&iommu_lock, flags);
    107		list_add(&entry->node, &cache);
    108		spin_unlock_irqrestore(&iommu_lock, flags);
    109	}
    110
    111	return pwrdm;
    112}
    113
    114int omap_iommu_set_pwrdm_constraint(struct platform_device *pdev, bool request,
    115				    u8 *pwrst)
    116{
    117	struct powerdomain *pwrdm;
    118	u8 next_pwrst;
    119	int ret = 0;
    120
    121	pwrdm = _get_pwrdm(&pdev->dev);
    122	if (!pwrdm)
    123		return -ENODEV;
    124
    125	if (request) {
    126		*pwrst = pwrdm_read_next_pwrst(pwrdm);
    127		omap_iommu_dra7_emu_swsup_config(pdev, true);
    128	}
    129
    130	if (*pwrst > PWRDM_POWER_RET)
    131		goto out;
    132
    133	next_pwrst = request ? PWRDM_POWER_ON : *pwrst;
    134
    135	ret = pwrdm_set_next_pwrst(pwrdm, next_pwrst);
    136
    137out:
    138	if (!request)
    139		omap_iommu_dra7_emu_swsup_config(pdev, false);
    140
    141	return ret;
    142}