linux/drivers/soc/samsung/exynos-asv.c
Dan Carpenter 89e551e838 soc: samsung: exynos-asv: Potential NULL dereference in exynos_asv_update_opps()
The dev_pm_opp_get_opp_table() returns error pointers if it's disabled
in the config and it returns NULL if there is an error.  This code only
checks for error pointers so it could lead to an Oops inside the
dev_pm_opp_put_opp_table() function.

Fixes: 5ea428595c ("soc: samsung: Add Exynos Adaptive Supply Voltage driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
2019-10-30 19:04:32 +01:00

178 lines
3.9 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2019 Samsung Electronics Co., Ltd.
* http://www.samsung.com/
* Author: Sylwester Nawrocki <s.nawrocki@samsung.com>
*
* Samsung Exynos SoC Adaptive Supply Voltage support
*/
#include <linux/cpu.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/pm_opp.h>
#include <linux/regmap.h>
#include <linux/soc/samsung/exynos-chipid.h>
#include "exynos-asv.h"
#include "exynos5422-asv.h"
#define MHZ 1000000U
static int exynos_asv_update_cpu_opps(struct exynos_asv *asv,
struct device *cpu)
{
struct exynos_asv_subsys *subsys = NULL;
struct dev_pm_opp *opp;
unsigned int opp_freq;
int i;
for (i = 0; i < ARRAY_SIZE(asv->subsys); i++) {
if (of_device_is_compatible(cpu->of_node,
asv->subsys[i].cpu_dt_compat)) {
subsys = &asv->subsys[i];
break;
}
}
if (!subsys)
return -EINVAL;
for (i = 0; i < subsys->table.num_rows; i++) {
unsigned int new_volt, volt;
int ret;
opp_freq = exynos_asv_opp_get_frequency(subsys, i);
opp = dev_pm_opp_find_freq_exact(cpu, opp_freq * MHZ, true);
if (IS_ERR(opp)) {
dev_info(asv->dev, "cpu%d opp%d, freq: %u missing\n",
cpu->id, i, opp_freq);
continue;
}
volt = dev_pm_opp_get_voltage(opp);
new_volt = asv->opp_get_voltage(subsys, i, volt);
dev_pm_opp_put(opp);
if (new_volt == volt)
continue;
ret = dev_pm_opp_adjust_voltage(cpu, opp_freq * MHZ,
new_volt, new_volt, new_volt);
if (ret < 0)
dev_err(asv->dev,
"Failed to adjust OPP %u Hz/%u uV for cpu%d\n",
opp_freq, new_volt, cpu->id);
else
dev_dbg(asv->dev,
"Adjusted OPP %u Hz/%u -> %u uV, cpu%d\n",
opp_freq, volt, new_volt, cpu->id);
}
return 0;
}
static int exynos_asv_update_opps(struct exynos_asv *asv)
{
struct opp_table *last_opp_table = NULL;
struct device *cpu;
int ret, cpuid;
for_each_possible_cpu(cpuid) {
struct opp_table *opp_table;
cpu = get_cpu_device(cpuid);
if (!cpu)
continue;
opp_table = dev_pm_opp_get_opp_table(cpu);
if (IS_ERR_OR_NULL(opp_table))
continue;
if (!last_opp_table || opp_table != last_opp_table) {
last_opp_table = opp_table;
ret = exynos_asv_update_cpu_opps(asv, cpu);
if (ret < 0)
dev_err(asv->dev, "Couldn't udate OPPs for cpu%d\n",
cpuid);
}
dev_pm_opp_put_opp_table(opp_table);
}
return 0;
}
static int exynos_asv_probe(struct platform_device *pdev)
{
int (*probe_func)(struct exynos_asv *asv);
struct exynos_asv *asv;
struct device *cpu_dev;
u32 product_id = 0;
int ret, i;
cpu_dev = get_cpu_device(0);
ret = dev_pm_opp_get_opp_count(cpu_dev);
if (ret < 0)
return -EPROBE_DEFER;
asv = devm_kzalloc(&pdev->dev, sizeof(*asv), GFP_KERNEL);
if (!asv)
return -ENOMEM;
asv->chipid_regmap = device_node_to_regmap(pdev->dev.of_node);
if (IS_ERR(asv->chipid_regmap)) {
dev_err(&pdev->dev, "Could not find syscon regmap\n");
return PTR_ERR(asv->chipid_regmap);
}
regmap_read(asv->chipid_regmap, EXYNOS_CHIPID_REG_PRO_ID, &product_id);
switch (product_id & EXYNOS_MASK) {
case 0xE5422000:
probe_func = exynos5422_asv_init;
break;
default:
return -ENODEV;
}
ret = of_property_read_u32(pdev->dev.of_node, "samsung,asv-bin",
&asv->of_bin);
if (ret < 0)
asv->of_bin = -EINVAL;
asv->dev = &pdev->dev;
dev_set_drvdata(&pdev->dev, asv);
for (i = 0; i < ARRAY_SIZE(asv->subsys); i++)
asv->subsys[i].asv = asv;
ret = probe_func(asv);
if (ret < 0)
return ret;
return exynos_asv_update_opps(asv);
}
static const struct of_device_id exynos_asv_of_device_ids[] = {
{ .compatible = "samsung,exynos4210-chipid" },
{}
};
static struct platform_driver exynos_asv_driver = {
.driver = {
.name = "exynos-asv",
.of_match_table = exynos_asv_of_device_ids,
},
.probe = exynos_asv_probe,
};
module_platform_driver(exynos_asv_driver);