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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exynos-nocp.c (7452B)


      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * exynos-nocp.c - Exynos NoC (Network On Chip) Probe support
      4 *
      5 * Copyright (c) 2016 Samsung Electronics Co., Ltd.
      6 * Author : Chanwoo Choi <cw00.choi@samsung.com>
      7 */
      8
      9#include <linux/clk.h>
     10#include <linux/module.h>
     11#include <linux/devfreq-event.h>
     12#include <linux/kernel.h>
     13#include <linux/of_address.h>
     14#include <linux/platform_device.h>
     15#include <linux/regmap.h>
     16
     17#include "exynos-nocp.h"
     18
     19struct exynos_nocp {
     20	struct devfreq_event_dev *edev;
     21	struct devfreq_event_desc desc;
     22
     23	struct device *dev;
     24
     25	struct regmap *regmap;
     26	struct clk *clk;
     27};
     28
     29/*
     30 * The devfreq-event ops structure for nocp probe.
     31 */
     32static int exynos_nocp_set_event(struct devfreq_event_dev *edev)
     33{
     34	struct exynos_nocp *nocp = devfreq_event_get_drvdata(edev);
     35	int ret;
     36
     37	/* Disable NoC probe */
     38	ret = regmap_update_bits(nocp->regmap, NOCP_MAIN_CTL,
     39				NOCP_MAIN_CTL_STATEN_MASK, 0);
     40	if (ret < 0) {
     41		dev_err(nocp->dev, "failed to disable the NoC probe device\n");
     42		return ret;
     43	}
     44
     45	/* Set a statistics dump period to 0 */
     46	ret = regmap_write(nocp->regmap, NOCP_STAT_PERIOD, 0x0);
     47	if (ret < 0)
     48		goto out;
     49
     50	/* Set the IntEvent fields of *_SRC */
     51	ret = regmap_update_bits(nocp->regmap, NOCP_COUNTERS_0_SRC,
     52				NOCP_CNT_SRC_INTEVENT_MASK,
     53				NOCP_CNT_SRC_INTEVENT_BYTE_MASK);
     54	if (ret < 0)
     55		goto out;
     56
     57	ret = regmap_update_bits(nocp->regmap, NOCP_COUNTERS_1_SRC,
     58				NOCP_CNT_SRC_INTEVENT_MASK,
     59				NOCP_CNT_SRC_INTEVENT_CHAIN_MASK);
     60	if (ret < 0)
     61		goto out;
     62
     63	ret = regmap_update_bits(nocp->regmap, NOCP_COUNTERS_2_SRC,
     64				NOCP_CNT_SRC_INTEVENT_MASK,
     65				NOCP_CNT_SRC_INTEVENT_CYCLE_MASK);
     66	if (ret < 0)
     67		goto out;
     68
     69	ret = regmap_update_bits(nocp->regmap, NOCP_COUNTERS_3_SRC,
     70				NOCP_CNT_SRC_INTEVENT_MASK,
     71				NOCP_CNT_SRC_INTEVENT_CHAIN_MASK);
     72	if (ret < 0)
     73		goto out;
     74
     75
     76	/* Set an alarm with a max/min value of 0 to generate StatALARM */
     77	ret = regmap_write(nocp->regmap, NOCP_STAT_ALARM_MIN, 0x0);
     78	if (ret < 0)
     79		goto out;
     80
     81	ret = regmap_write(nocp->regmap, NOCP_STAT_ALARM_MAX, 0x0);
     82	if (ret < 0)
     83		goto out;
     84
     85	/* Set AlarmMode */
     86	ret = regmap_update_bits(nocp->regmap, NOCP_COUNTERS_0_ALARM_MODE,
     87				NOCP_CNT_ALARM_MODE_MASK,
     88				NOCP_CNT_ALARM_MODE_MIN_MAX_MASK);
     89	if (ret < 0)
     90		goto out;
     91
     92	ret = regmap_update_bits(nocp->regmap, NOCP_COUNTERS_1_ALARM_MODE,
     93				NOCP_CNT_ALARM_MODE_MASK,
     94				NOCP_CNT_ALARM_MODE_MIN_MAX_MASK);
     95	if (ret < 0)
     96		goto out;
     97
     98	ret = regmap_update_bits(nocp->regmap, NOCP_COUNTERS_2_ALARM_MODE,
     99				NOCP_CNT_ALARM_MODE_MASK,
    100				NOCP_CNT_ALARM_MODE_MIN_MAX_MASK);
    101	if (ret < 0)
    102		goto out;
    103
    104	ret = regmap_update_bits(nocp->regmap, NOCP_COUNTERS_3_ALARM_MODE,
    105				NOCP_CNT_ALARM_MODE_MASK,
    106				NOCP_CNT_ALARM_MODE_MIN_MAX_MASK);
    107	if (ret < 0)
    108		goto out;
    109
    110	/* Enable the measurements by setting AlarmEn and StatEn */
    111	ret = regmap_update_bits(nocp->regmap, NOCP_MAIN_CTL,
    112			NOCP_MAIN_CTL_STATEN_MASK | NOCP_MAIN_CTL_ALARMEN_MASK,
    113			NOCP_MAIN_CTL_STATEN_MASK | NOCP_MAIN_CTL_ALARMEN_MASK);
    114	if (ret < 0)
    115		goto out;
    116
    117	/* Set GlobalEN */
    118	ret = regmap_update_bits(nocp->regmap, NOCP_CFG_CTL,
    119				NOCP_CFG_CTL_GLOBALEN_MASK,
    120				NOCP_CFG_CTL_GLOBALEN_MASK);
    121	if (ret < 0)
    122		goto out;
    123
    124	/* Enable NoC probe */
    125	ret = regmap_update_bits(nocp->regmap, NOCP_MAIN_CTL,
    126				NOCP_MAIN_CTL_STATEN_MASK,
    127				NOCP_MAIN_CTL_STATEN_MASK);
    128	if (ret < 0)
    129		goto out;
    130
    131	return 0;
    132
    133out:
    134	/* Reset NoC probe */
    135	if (regmap_update_bits(nocp->regmap, NOCP_MAIN_CTL,
    136				NOCP_MAIN_CTL_STATEN_MASK, 0)) {
    137		dev_err(nocp->dev, "Failed to reset NoC probe device\n");
    138	}
    139
    140	return ret;
    141}
    142
    143static int exynos_nocp_get_event(struct devfreq_event_dev *edev,
    144				struct devfreq_event_data *edata)
    145{
    146	struct exynos_nocp *nocp = devfreq_event_get_drvdata(edev);
    147	unsigned int counter[4];
    148	int ret;
    149
    150	/* Read cycle count */
    151	ret = regmap_read(nocp->regmap, NOCP_COUNTERS_0_VAL, &counter[0]);
    152	if (ret < 0)
    153		goto out;
    154
    155	ret = regmap_read(nocp->regmap, NOCP_COUNTERS_1_VAL, &counter[1]);
    156	if (ret < 0)
    157		goto out;
    158
    159	ret = regmap_read(nocp->regmap, NOCP_COUNTERS_2_VAL, &counter[2]);
    160	if (ret < 0)
    161		goto out;
    162
    163	ret = regmap_read(nocp->regmap, NOCP_COUNTERS_3_VAL, &counter[3]);
    164	if (ret < 0)
    165		goto out;
    166
    167	edata->load_count = ((counter[1] << 16) | counter[0]);
    168	edata->total_count = ((counter[3] << 16) | counter[2]);
    169
    170	dev_dbg(&edev->dev, "%s (event: %ld/%ld)\n", edev->desc->name,
    171					edata->load_count, edata->total_count);
    172
    173	return 0;
    174
    175out:
    176	dev_err(nocp->dev, "Failed to read the counter of NoC probe device\n");
    177
    178	return ret;
    179}
    180
    181static const struct devfreq_event_ops exynos_nocp_ops = {
    182	.set_event = exynos_nocp_set_event,
    183	.get_event = exynos_nocp_get_event,
    184};
    185
    186static const struct of_device_id exynos_nocp_id_match[] = {
    187	{ .compatible = "samsung,exynos5420-nocp", },
    188	{ /* sentinel */ },
    189};
    190MODULE_DEVICE_TABLE(of, exynos_nocp_id_match);
    191
    192static struct regmap_config exynos_nocp_regmap_config = {
    193	.reg_bits = 32,
    194	.val_bits = 32,
    195	.reg_stride = 4,
    196	.max_register = NOCP_COUNTERS_3_VAL,
    197};
    198
    199static int exynos_nocp_parse_dt(struct platform_device *pdev,
    200				struct exynos_nocp *nocp)
    201{
    202	struct device *dev = nocp->dev;
    203	struct device_node *np = dev->of_node;
    204	struct resource *res;
    205	void __iomem *base;
    206
    207	if (!np) {
    208		dev_err(dev, "failed to find devicetree node\n");
    209		return -EINVAL;
    210	}
    211
    212	nocp->clk = devm_clk_get(dev, "nocp");
    213	if (IS_ERR(nocp->clk))
    214		nocp->clk = NULL;
    215
    216	/* Maps the memory mapped IO to control nocp register */
    217	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    218	base = devm_ioremap_resource(dev, res);
    219	if (IS_ERR(base))
    220		return PTR_ERR(base);
    221
    222	exynos_nocp_regmap_config.max_register = resource_size(res) - 4;
    223
    224	nocp->regmap = devm_regmap_init_mmio(dev, base,
    225					&exynos_nocp_regmap_config);
    226	if (IS_ERR(nocp->regmap)) {
    227		dev_err(dev, "failed to initialize regmap\n");
    228		return PTR_ERR(nocp->regmap);
    229	}
    230
    231	return 0;
    232}
    233
    234static int exynos_nocp_probe(struct platform_device *pdev)
    235{
    236	struct device *dev = &pdev->dev;
    237	struct device_node *np = dev->of_node;
    238	struct exynos_nocp *nocp;
    239	int ret;
    240
    241	nocp = devm_kzalloc(&pdev->dev, sizeof(*nocp), GFP_KERNEL);
    242	if (!nocp)
    243		return -ENOMEM;
    244
    245	nocp->dev = &pdev->dev;
    246
    247	/* Parse dt data to get resource */
    248	ret = exynos_nocp_parse_dt(pdev, nocp);
    249	if (ret < 0) {
    250		dev_err(&pdev->dev,
    251			"failed to parse devicetree for resource\n");
    252		return ret;
    253	}
    254
    255	/* Add devfreq-event device to measure the bandwidth of NoC */
    256	nocp->desc.ops = &exynos_nocp_ops;
    257	nocp->desc.driver_data = nocp;
    258	nocp->desc.name = np->full_name;
    259	nocp->edev = devm_devfreq_event_add_edev(&pdev->dev, &nocp->desc);
    260	if (IS_ERR(nocp->edev)) {
    261		dev_err(&pdev->dev,
    262			"failed to add devfreq-event device\n");
    263		return PTR_ERR(nocp->edev);
    264	}
    265	platform_set_drvdata(pdev, nocp);
    266
    267	ret = clk_prepare_enable(nocp->clk);
    268	if (ret) {
    269		dev_err(&pdev->dev, "failed to prepare ppmu clock\n");
    270		return ret;
    271	}
    272
    273	pr_info("exynos-nocp: new NoC Probe device registered: %s\n",
    274			dev_name(dev));
    275
    276	return 0;
    277}
    278
    279static int exynos_nocp_remove(struct platform_device *pdev)
    280{
    281	struct exynos_nocp *nocp = platform_get_drvdata(pdev);
    282
    283	clk_disable_unprepare(nocp->clk);
    284
    285	return 0;
    286}
    287
    288static struct platform_driver exynos_nocp_driver = {
    289	.probe	= exynos_nocp_probe,
    290	.remove	= exynos_nocp_remove,
    291	.driver = {
    292		.name	= "exynos-nocp",
    293		.of_match_table = exynos_nocp_id_match,
    294	},
    295};
    296module_platform_driver(exynos_nocp_driver);
    297
    298MODULE_DESCRIPTION("Exynos NoC (Network on Chip) Probe driver");
    299MODULE_AUTHOR("Chanwoo Choi <cw00.choi@samsung.com>");
    300MODULE_LICENSE("GPL");