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1// SPDX-License-Identifier: GPL-2.0-only2// Copyright (c) 2018-2021 Intel Corporation3 4#include <linux/bitfield.h>5#include <linux/peci.h>6#include <linux/peci-cpu.h>7#include <linux/slab.h>8 9#include "internal.h"10 11/*12 * PECI device can be removed using sysfs, but the removal can also happen as13 * a result of controller being removed.14 * Mutex is used to protect PECI device from being double-deleted.15 */16static DEFINE_MUTEX(peci_device_del_lock);17 18#define REVISION_NUM_MASK GENMASK(15, 8)19static int peci_get_revision(struct peci_device *device, u8 *revision)20{21 struct peci_request *req;22 u64 dib;23 24 req = peci_xfer_get_dib(device);25 if (IS_ERR(req))26 return PTR_ERR(req);27 28 /*29 * PECI device may be in a state where it is unable to return a proper30 * DIB, in which case it returns 0 as DIB value.31 * Let's treat this as an error to avoid carrying on with the detection32 * using invalid revision.33 */34 dib = peci_request_dib_read(req);35 if (dib == 0) {36 peci_request_free(req);37 return -EIO;38 }39 40 *revision = FIELD_GET(REVISION_NUM_MASK, dib);41 42 peci_request_free(req);43 44 return 0;45}46 47static int peci_get_cpu_id(struct peci_device *device, u32 *cpu_id)48{49 struct peci_request *req;50 int ret;51 52 req = peci_xfer_pkg_cfg_readl(device, PECI_PCS_PKG_ID, PECI_PKG_ID_CPU_ID);53 if (IS_ERR(req))54 return PTR_ERR(req);55 56 ret = peci_request_status(req);57 if (ret)58 goto out_req_free;59 60 *cpu_id = peci_request_data_readl(req);61out_req_free:62 peci_request_free(req);63 64 return ret;65}66 67static unsigned int peci_x86_cpu_family(unsigned int sig)68{69 unsigned int x86;70 71 x86 = (sig >> 8) & 0xf;72 73 if (x86 == 0xf)74 x86 += (sig >> 20) & 0xff;75 76 return x86;77}78 79static unsigned int peci_x86_cpu_model(unsigned int sig)80{81 unsigned int fam, model;82 83 fam = peci_x86_cpu_family(sig);84 85 model = (sig >> 4) & 0xf;86 87 if (fam >= 0x6)88 model += ((sig >> 16) & 0xf) << 4;89 90 return model;91}92 93static int peci_device_info_init(struct peci_device *device)94{95 u8 revision;96 u32 cpu_id;97 int ret;98 99 ret = peci_get_cpu_id(device, &cpu_id);100 if (ret)101 return ret;102 103 device->info.x86_vfm = IFM(peci_x86_cpu_family(cpu_id), peci_x86_cpu_model(cpu_id));104 105 ret = peci_get_revision(device, &revision);106 if (ret)107 return ret;108 device->info.peci_revision = revision;109 110 device->info.socket_id = device->addr - PECI_BASE_ADDR;111 112 return 0;113}114 115static int peci_detect(struct peci_controller *controller, u8 addr)116{117 /*118 * PECI Ping is a command encoded by tx_len = 0, rx_len = 0.119 * We expect correct Write FCS if the device at the target address120 * is able to respond.121 */122 struct peci_request req = { 0 };123 int ret;124 125 mutex_lock(&controller->bus_lock);126 ret = controller->ops->xfer(controller, addr, &req);127 mutex_unlock(&controller->bus_lock);128 129 return ret;130}131 132static bool peci_addr_valid(u8 addr)133{134 return addr >= PECI_BASE_ADDR && addr < PECI_BASE_ADDR + PECI_DEVICE_NUM_MAX;135}136 137static int peci_dev_exists(struct device *dev, void *data)138{139 struct peci_device *device = to_peci_device(dev);140 u8 *addr = data;141 142 if (device->addr == *addr)143 return -EBUSY;144 145 return 0;146}147 148int peci_device_create(struct peci_controller *controller, u8 addr)149{150 struct peci_device *device;151 int ret;152 153 if (!peci_addr_valid(addr))154 return -EINVAL;155 156 /* Check if we have already detected this device before. */157 ret = device_for_each_child(&controller->dev, &addr, peci_dev_exists);158 if (ret)159 return 0;160 161 ret = peci_detect(controller, addr);162 if (ret) {163 /*164 * Device not present or host state doesn't allow successful165 * detection at this time.166 */167 if (ret == -EIO || ret == -ETIMEDOUT)168 return 0;169 170 return ret;171 }172 173 device = kzalloc(sizeof(*device), GFP_KERNEL);174 if (!device)175 return -ENOMEM;176 177 device_initialize(&device->dev);178 179 device->addr = addr;180 device->dev.parent = &controller->dev;181 device->dev.bus = &peci_bus_type;182 device->dev.type = &peci_device_type;183 184 ret = peci_device_info_init(device);185 if (ret)186 goto err_put;187 188 ret = dev_set_name(&device->dev, "%d-%02x", controller->id, device->addr);189 if (ret)190 goto err_put;191 192 ret = device_add(&device->dev);193 if (ret)194 goto err_put;195 196 return 0;197 198err_put:199 put_device(&device->dev);200 201 return ret;202}203 204void peci_device_destroy(struct peci_device *device)205{206 mutex_lock(&peci_device_del_lock);207 if (!device->deleted) {208 device_unregister(&device->dev);209 device->deleted = true;210 }211 mutex_unlock(&peci_device_del_lock);212}213 214int __peci_driver_register(struct peci_driver *driver, struct module *owner,215 const char *mod_name)216{217 driver->driver.bus = &peci_bus_type;218 driver->driver.owner = owner;219 driver->driver.mod_name = mod_name;220 221 if (!driver->probe) {222 pr_err("peci: trying to register driver without probe callback\n");223 return -EINVAL;224 }225 226 if (!driver->id_table) {227 pr_err("peci: trying to register driver without device id table\n");228 return -EINVAL;229 }230 231 return driver_register(&driver->driver);232}233EXPORT_SYMBOL_NS_GPL(__peci_driver_register, PECI);234 235void peci_driver_unregister(struct peci_driver *driver)236{237 driver_unregister(&driver->driver);238}239EXPORT_SYMBOL_NS_GPL(peci_driver_unregister, PECI);240 241static void peci_device_release(struct device *dev)242{243 struct peci_device *device = to_peci_device(dev);244 245 kfree(device);246}247 248const struct device_type peci_device_type = {249 .groups = peci_device_groups,250 .release = peci_device_release,251};252