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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coresight-config.c (8333B)


      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * Copyright(C) 2020 Linaro Limited. All rights reserved.
      4 * Author: Mike Leach <mike.leach@linaro.org>
      5 */
      6
      7#include <linux/sysfs.h>
      8#include "coresight-config.h"
      9#include "coresight-priv.h"
     10
     11/*
     12 * This provides a set of generic functions that operate on configurations
     13 * and features to manage the handling of parameters, the programming and
     14 * saving of registers used by features on devices.
     15 */
     16
     17/*
     18 * Write the value held in the register structure into the driver internal memory
     19 * location.
     20 */
     21static void cscfg_set_reg(struct cscfg_regval_csdev *reg_csdev)
     22{
     23	u32 *p_val32 = (u32 *)reg_csdev->driver_regval;
     24	u32 tmp32 = reg_csdev->reg_desc.val32;
     25
     26	if (reg_csdev->reg_desc.type & CS_CFG_REG_TYPE_VAL_64BIT) {
     27		*((u64 *)reg_csdev->driver_regval) = reg_csdev->reg_desc.val64;
     28		return;
     29	}
     30
     31	if (reg_csdev->reg_desc.type & CS_CFG_REG_TYPE_VAL_MASK) {
     32		tmp32 = *p_val32;
     33		tmp32 &= ~reg_csdev->reg_desc.mask32;
     34		tmp32 |= reg_csdev->reg_desc.val32 & reg_csdev->reg_desc.mask32;
     35	}
     36	*p_val32 = tmp32;
     37}
     38
     39/*
     40 * Read the driver value into the reg if this is marked as one we want to save.
     41 */
     42static void cscfg_save_reg(struct cscfg_regval_csdev *reg_csdev)
     43{
     44	if (!(reg_csdev->reg_desc.type & CS_CFG_REG_TYPE_VAL_SAVE))
     45		return;
     46	if (reg_csdev->reg_desc.type & CS_CFG_REG_TYPE_VAL_64BIT)
     47		reg_csdev->reg_desc.val64 = *(u64 *)(reg_csdev->driver_regval);
     48	else
     49		reg_csdev->reg_desc.val32 = *(u32 *)(reg_csdev->driver_regval);
     50}
     51
     52/*
     53 * Some register values are set from parameters. Initialise these registers
     54 * from the current parameter values.
     55 */
     56static void cscfg_init_reg_param(struct cscfg_feature_csdev *feat_csdev,
     57				 struct cscfg_regval_desc *reg_desc,
     58				 struct cscfg_regval_csdev *reg_csdev)
     59{
     60	struct cscfg_parameter_csdev *param_csdev;
     61
     62	/* for param, load routines have validated the index */
     63	param_csdev = &feat_csdev->params_csdev[reg_desc->param_idx];
     64	param_csdev->reg_csdev = reg_csdev;
     65	param_csdev->val64 = reg_csdev->reg_desc.type & CS_CFG_REG_TYPE_VAL_64BIT;
     66
     67	if (param_csdev->val64)
     68		reg_csdev->reg_desc.val64 = param_csdev->current_value;
     69	else
     70		reg_csdev->reg_desc.val32 = (u32)param_csdev->current_value;
     71}
     72
     73/* set values into the driver locations referenced in cscfg_reg_csdev */
     74static int cscfg_set_on_enable(struct cscfg_feature_csdev *feat_csdev)
     75{
     76	unsigned long flags;
     77	int i;
     78
     79	spin_lock_irqsave(feat_csdev->drv_spinlock, flags);
     80	for (i = 0; i < feat_csdev->nr_regs; i++)
     81		cscfg_set_reg(&feat_csdev->regs_csdev[i]);
     82	spin_unlock_irqrestore(feat_csdev->drv_spinlock, flags);
     83	dev_dbg(&feat_csdev->csdev->dev, "Feature %s: %s",
     84		feat_csdev->feat_desc->name, "set on enable");
     85	return 0;
     86}
     87
     88/* copy back values from the driver locations referenced in cscfg_reg_csdev */
     89static void cscfg_save_on_disable(struct cscfg_feature_csdev *feat_csdev)
     90{
     91	unsigned long flags;
     92	int i;
     93
     94	spin_lock_irqsave(feat_csdev->drv_spinlock, flags);
     95	for (i = 0; i < feat_csdev->nr_regs; i++)
     96		cscfg_save_reg(&feat_csdev->regs_csdev[i]);
     97	spin_unlock_irqrestore(feat_csdev->drv_spinlock, flags);
     98	dev_dbg(&feat_csdev->csdev->dev, "Feature %s: %s",
     99		feat_csdev->feat_desc->name, "save on disable");
    100}
    101
    102/* default reset - restore default values */
    103void cscfg_reset_feat(struct cscfg_feature_csdev *feat_csdev)
    104{
    105	struct cscfg_regval_desc *reg_desc;
    106	struct cscfg_regval_csdev *reg_csdev;
    107	int i;
    108
    109	/*
    110	 * set the default values for all parameters and regs from the
    111	 * relevant static descriptors.
    112	 */
    113	for (i = 0; i < feat_csdev->nr_params; i++)
    114		feat_csdev->params_csdev[i].current_value =
    115			feat_csdev->feat_desc->params_desc[i].value;
    116
    117	for (i = 0; i < feat_csdev->nr_regs; i++) {
    118		reg_desc = &feat_csdev->feat_desc->regs_desc[i];
    119		reg_csdev = &feat_csdev->regs_csdev[i];
    120		reg_csdev->reg_desc.type = reg_desc->type;
    121
    122		/* check if reg set from a parameter otherwise desc default */
    123		if (reg_desc->type & CS_CFG_REG_TYPE_VAL_PARAM)
    124			cscfg_init_reg_param(feat_csdev, reg_desc, reg_csdev);
    125		else
    126			/*
    127			 * for normal values the union between val64 & val32 + mask32
    128			 * allows us to init using the 64 bit value
    129			 */
    130			reg_csdev->reg_desc.val64 = reg_desc->val64;
    131	}
    132}
    133
    134/*
    135 * For the selected presets, we set the register associated with the parameter, to
    136 * the value of the preset index associated with the parameter.
    137 */
    138static int cscfg_update_presets(struct cscfg_config_csdev *config_csdev, int preset)
    139{
    140	int i, j, val_idx = 0, nr_cfg_params;
    141	struct cscfg_parameter_csdev *param_csdev;
    142	struct cscfg_feature_csdev *feat_csdev;
    143	const struct cscfg_config_desc *config_desc = config_csdev->config_desc;
    144	const char *name;
    145	const u64 *preset_base;
    146	u64 val;
    147
    148	/* preset in range 1 to nr_presets */
    149	if (preset < 1 || preset > config_desc->nr_presets)
    150		return -EINVAL;
    151	/*
    152	 * Go through the array of features, assigning preset values to
    153	 * feature parameters in the order they appear.
    154	 * There should be precisely the same number of preset values as the
    155	 * sum of number of parameters over all the features - but we will
    156	 * ensure there is no overrun.
    157	 */
    158	nr_cfg_params = config_desc->nr_total_params;
    159	preset_base = &config_desc->presets[(preset - 1) * nr_cfg_params];
    160	for (i = 0; i < config_csdev->nr_feat; i++) {
    161		feat_csdev = config_csdev->feats_csdev[i];
    162		if (!feat_csdev->nr_params)
    163			continue;
    164
    165		for (j = 0; j < feat_csdev->nr_params; j++) {
    166			param_csdev = &feat_csdev->params_csdev[j];
    167			name = feat_csdev->feat_desc->params_desc[j].name;
    168			val = preset_base[val_idx++];
    169			if (param_csdev->val64) {
    170				dev_dbg(&config_csdev->csdev->dev,
    171					"set param %s (%lld)", name, val);
    172				param_csdev->reg_csdev->reg_desc.val64 = val;
    173			} else {
    174				param_csdev->reg_csdev->reg_desc.val32 = (u32)val;
    175				dev_dbg(&config_csdev->csdev->dev,
    176					"set param %s (%d)", name, (u32)val);
    177			}
    178		}
    179
    180		/* exit early if all params filled */
    181		if (val_idx >= nr_cfg_params)
    182			break;
    183	}
    184	return 0;
    185}
    186
    187/*
    188 * if we are not using a preset, then need to update the feature params
    189 * with current values. This sets the register associated with the parameter
    190 * with the current value of that parameter.
    191 */
    192static int cscfg_update_curr_params(struct cscfg_config_csdev *config_csdev)
    193{
    194	int i, j;
    195	struct cscfg_feature_csdev *feat_csdev;
    196	struct cscfg_parameter_csdev *param_csdev;
    197	const char *name;
    198	u64 val;
    199
    200	for (i = 0; i < config_csdev->nr_feat; i++) {
    201		feat_csdev = config_csdev->feats_csdev[i];
    202		if (!feat_csdev->nr_params)
    203			continue;
    204		for (j = 0; j < feat_csdev->nr_params; j++) {
    205			param_csdev = &feat_csdev->params_csdev[j];
    206			name = feat_csdev->feat_desc->params_desc[j].name;
    207			val = param_csdev->current_value;
    208			if (param_csdev->val64) {
    209				dev_dbg(&config_csdev->csdev->dev,
    210					"set param %s (%lld)", name, val);
    211				param_csdev->reg_csdev->reg_desc.val64 = val;
    212			} else {
    213				param_csdev->reg_csdev->reg_desc.val32 = (u32)val;
    214				dev_dbg(&config_csdev->csdev->dev,
    215					"set param %s (%d)", name, (u32)val);
    216			}
    217		}
    218	}
    219	return 0;
    220}
    221
    222/*
    223 * Configuration values will be programmed into the driver locations if enabling, or read
    224 * from relevant locations on disable.
    225 */
    226static int cscfg_prog_config(struct cscfg_config_csdev *config_csdev, bool enable)
    227{
    228	int i, err = 0;
    229	struct cscfg_feature_csdev *feat_csdev;
    230	struct coresight_device *csdev;
    231
    232	for (i = 0; i < config_csdev->nr_feat; i++) {
    233		feat_csdev = config_csdev->feats_csdev[i];
    234		csdev = feat_csdev->csdev;
    235		dev_dbg(&csdev->dev, "cfg %s;  %s feature:%s", config_csdev->config_desc->name,
    236			enable ? "enable" : "disable", feat_csdev->feat_desc->name);
    237
    238		if (enable)
    239			err = cscfg_set_on_enable(feat_csdev);
    240		else
    241			cscfg_save_on_disable(feat_csdev);
    242
    243		if (err)
    244			break;
    245	}
    246	return err;
    247}
    248
    249/*
    250 * Enable configuration for the device. Will result in the internal driver data
    251 * being updated ready for programming into the device.
    252 *
    253 * @config_csdev:	config_csdev to set.
    254 * @preset:		preset values to use - 0 for default.
    255 */
    256int cscfg_csdev_enable_config(struct cscfg_config_csdev *config_csdev, int preset)
    257{
    258	int err = 0;
    259
    260	if (preset)
    261		err = cscfg_update_presets(config_csdev, preset);
    262	else
    263		err = cscfg_update_curr_params(config_csdev);
    264	if (!err)
    265		err = cscfg_prog_config(config_csdev, true);
    266	return err;
    267}
    268
    269void cscfg_csdev_disable_config(struct cscfg_config_csdev *config_csdev)
    270{
    271	cscfg_prog_config(config_csdev, false);
    272}