| /* |
| * |
| * (C) COPYRIGHT 2017 ARM Limited. All rights reserved. |
| * |
| * This program is free software and is provided to you under the terms of the |
| * GNU General Public License version 2 as published by the Free Software |
| * Foundation, and any use by you of this program is subject to the terms |
| * of such GNU licence. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, you can access it online at |
| * http://www.gnu.org/licenses/gpl-2.0.html. |
| * |
| * SPDX-License-Identifier: GPL-2.0 |
| * |
| */ |
| |
| #include <linux/init.h> |
| #include <linux/module.h> |
| #include <linux/kernel.h> |
| #include <linux/platform_device.h> |
| #include <linux/of.h> |
| #include <linux/of_platform.h> |
| #include <linux/compiler.h> |
| |
| #include <linux/protected_mode_switcher.h> |
| |
| /* |
| * Protected Mode Switch |
| */ |
| |
| #define SMC_FAST_CALL (1 << 31) |
| #define SMC_64 (1 << 30) |
| #define SMC_OEN_OFFSET 24 |
| #define SMC_OEN_SIP (2 << SMC_OEN_OFFSET) |
| |
| struct smc_protected_mode_device { |
| u16 smc_fid_enable; |
| u16 smc_fid_disable; |
| struct device *dev; |
| }; |
| |
| asmlinkage u64 __invoke_protected_mode_switch_smc(u64, u64, u64, u64); |
| |
| static u64 invoke_smc(u32 oen, u16 function_number, bool smc64, |
| u64 arg0, u64 arg1, u64 arg2) |
| { |
| u32 fid = 0; |
| |
| fid |= SMC_FAST_CALL; /* Bit 31: Fast call */ |
| if (smc64) |
| fid |= SMC_64; /* Bit 30: 1=SMC64, 0=SMC32 */ |
| fid |= oen; /* Bit 29:24: OEN */ |
| /* Bit 23:16: Must be zero for fast calls */ |
| fid |= (function_number); /* Bit 15:0: function number */ |
| |
| return __invoke_protected_mode_switch_smc(fid, arg0, arg1, arg2); |
| } |
| |
| static int protected_mode_enable(struct protected_mode_device *protected_dev) |
| { |
| struct smc_protected_mode_device *sdev = protected_dev->data; |
| |
| if (!sdev) |
| /* Not supported */ |
| return -EINVAL; |
| |
| return invoke_smc(SMC_OEN_SIP, |
| sdev->smc_fid_enable, false, |
| 0, 0, 0); |
| |
| } |
| |
| static int protected_mode_disable(struct protected_mode_device *protected_dev) |
| { |
| struct smc_protected_mode_device *sdev = protected_dev->data; |
| |
| if (!sdev) |
| /* Not supported */ |
| return -EINVAL; |
| |
| return invoke_smc(SMC_OEN_SIP, |
| sdev->smc_fid_disable, false, |
| 0, 0, 0); |
| } |
| |
| |
| static int protected_mode_probe(struct platform_device *pdev) |
| { |
| struct device *dev = &pdev->dev; |
| struct protected_mode_device *protected_dev; |
| struct smc_protected_mode_device *sdev; |
| u32 tmp = 0; |
| |
| protected_dev = devm_kzalloc(&pdev->dev, sizeof(*protected_dev), |
| GFP_KERNEL); |
| if (!protected_dev) |
| return -ENOMEM; |
| |
| sdev = devm_kzalloc(&pdev->dev, sizeof(*sdev), GFP_KERNEL); |
| if (!sdev) { |
| devm_kfree(&pdev->dev, protected_dev); |
| return -ENOMEM; |
| } |
| |
| protected_dev->data = sdev; |
| protected_dev->ops.protected_mode_enable = protected_mode_enable; |
| protected_dev->ops.protected_mode_disable = protected_mode_disable; |
| sdev->dev = dev; |
| |
| if (!of_property_read_u32(dev->of_node, "arm,smc,protected_enable", |
| &tmp)) |
| sdev->smc_fid_enable = tmp; |
| |
| if (!of_property_read_u32(dev->of_node, "arm,smc,protected_disable", |
| &tmp)) |
| sdev->smc_fid_disable = tmp; |
| |
| /* Check older property names, for compatibility with outdated DTBs */ |
| if (!of_property_read_u32(dev->of_node, "arm,smc,secure_enable", &tmp)) |
| sdev->smc_fid_enable = tmp; |
| |
| if (!of_property_read_u32(dev->of_node, "arm,smc,secure_disable", &tmp)) |
| sdev->smc_fid_disable = tmp; |
| |
| platform_set_drvdata(pdev, protected_dev); |
| |
| dev_info(&pdev->dev, "Protected mode switcher %s loaded\n", pdev->name); |
| dev_info(&pdev->dev, "SMC enable: 0x%x\n", sdev->smc_fid_enable); |
| dev_info(&pdev->dev, "SMC disable: 0x%x\n", sdev->smc_fid_disable); |
| |
| return 0; |
| } |
| |
| static int protected_mode_remove(struct platform_device *pdev) |
| { |
| dev_info(&pdev->dev, "Protected mode switcher %s removed\n", |
| pdev->name); |
| |
| return 0; |
| } |
| |
| static const struct of_device_id protected_mode_dt_ids[] = { |
| { .compatible = "arm,smc-protected-mode-switcher" }, |
| { .compatible = "arm,secure-mode-switcher" }, |
| { /* sentinel */ } |
| }; |
| MODULE_DEVICE_TABLE(of, protected_mode_dt_ids); |
| |
| static struct platform_driver protected_mode_driver = { |
| .probe = protected_mode_probe, |
| .remove = protected_mode_remove, |
| .driver = { |
| .name = "smc-protected-mode-switcher", |
| .owner = THIS_MODULE, |
| .of_match_table = of_match_ptr(protected_mode_dt_ids), |
| } |
| }; |
| |
| module_platform_driver(protected_mode_driver); |
| |
| MODULE_LICENSE("GPL"); |
| MODULE_AUTHOR("ARM Ltd."); |
| MODULE_VERSION("1.0"); |