diff options
Diffstat (limited to 'drivers/platform/x86/intel_speed_select_if/isst_if_common.c')
| -rw-r--r-- | drivers/platform/x86/intel_speed_select_if/isst_if_common.c | 672 |
1 files changed, 672 insertions, 0 deletions
diff --git a/drivers/platform/x86/intel_speed_select_if/isst_if_common.c b/drivers/platform/x86/intel_speed_select_if/isst_if_common.c new file mode 100644 index 000000000000..68d75391db57 --- /dev/null +++ b/drivers/platform/x86/intel_speed_select_if/isst_if_common.c @@ -0,0 +1,672 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Intel Speed Select Interface: Common functions + * Copyright (c) 2019, Intel Corporation. + * All rights reserved. + * + * Author: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> + */ + +#include <linux/cpufeature.h> +#include <linux/cpuhotplug.h> +#include <linux/fs.h> +#include <linux/hashtable.h> +#include <linux/miscdevice.h> +#include <linux/module.h> +#include <linux/pci.h> +#include <linux/sched/signal.h> +#include <linux/slab.h> +#include <linux/uaccess.h> +#include <uapi/linux/isst_if.h> + +#include "isst_if_common.h" + +#define MSR_THREAD_ID_INFO 0x53 +#define MSR_CPU_BUS_NUMBER 0x128 + +static struct isst_if_cmd_cb punit_callbacks[ISST_IF_DEV_MAX]; + +static int punit_msr_white_list[] = { + MSR_TURBO_RATIO_LIMIT, + MSR_CONFIG_TDP_CONTROL, +}; + +struct isst_valid_cmd_ranges { + u16 cmd; + u16 sub_cmd_beg; + u16 sub_cmd_end; +}; + +struct isst_cmd_set_req_type { + u16 cmd; + u16 sub_cmd; + u16 param; +}; + +static const struct isst_valid_cmd_ranges isst_valid_cmds[] = { + {0xD0, 0x00, 0x03}, + {0x7F, 0x00, 0x0B}, + {0x7F, 0x10, 0x12}, + {0x7F, 0x20, 0x23}, +}; + +static const struct isst_cmd_set_req_type isst_cmd_set_reqs[] = { + {0xD0, 0x00, 0x08}, + {0xD0, 0x01, 0x08}, + {0xD0, 0x02, 0x08}, + {0xD0, 0x03, 0x08}, + {0x7F, 0x02, 0x00}, + {0x7F, 0x08, 0x00}, +}; + +struct isst_cmd { + struct hlist_node hnode; + u64 data; + u32 cmd; + int cpu; + int mbox_cmd_type; + u32 param; +}; + +static DECLARE_HASHTABLE(isst_hash, 8); +static DEFINE_MUTEX(isst_hash_lock); + +static int isst_store_new_cmd(int cmd, u32 cpu, int mbox_cmd_type, u32 param, + u32 data) +{ + struct isst_cmd *sst_cmd; + + sst_cmd = kmalloc(sizeof(*sst_cmd), GFP_KERNEL); + if (!sst_cmd) + return -ENOMEM; + + sst_cmd->cpu = cpu; + sst_cmd->cmd = cmd; + sst_cmd->mbox_cmd_type = mbox_cmd_type; + sst_cmd->param = param; + sst_cmd->data = data; + + hash_add(isst_hash, &sst_cmd->hnode, sst_cmd->cmd); + + return 0; +} + +static void isst_delete_hash(void) +{ + struct isst_cmd *sst_cmd; + struct hlist_node *tmp; + int i; + + hash_for_each_safe(isst_hash, i, tmp, sst_cmd, hnode) { + hash_del(&sst_cmd->hnode); + kfree(sst_cmd); + } +} + +/** + * isst_store_cmd() - Store command to a hash table + * @cmd: Mailbox command. + * @sub_cmd: Mailbox sub-command or MSR id. + * @mbox_cmd_type: Mailbox or MSR command. + * @param: Mailbox parameter. + * @data: Mailbox request data or MSR data. + * + * Stores the command to a hash table if there is no such command already + * stored. If already stored update the latest parameter and data for the + * command. + * + * Return: Return result of store to hash table, 0 for success, others for + * failure. + */ +int isst_store_cmd(int cmd, int sub_cmd, u32 cpu, int mbox_cmd_type, + u32 param, u64 data) +{ + struct isst_cmd *sst_cmd; + int full_cmd, ret; + + full_cmd = (cmd & GENMASK_ULL(15, 0)) << 16; + full_cmd |= (sub_cmd & GENMASK_ULL(15, 0)); + mutex_lock(&isst_hash_lock); + hash_for_each_possible(isst_hash, sst_cmd, hnode, full_cmd) { + if (sst_cmd->cmd == full_cmd && sst_cmd->cpu == cpu && + sst_cmd->mbox_cmd_type == mbox_cmd_type) { + sst_cmd->param = param; + sst_cmd->data = data; + mutex_unlock(&isst_hash_lock); + return 0; + } + } + + ret = isst_store_new_cmd(full_cmd, cpu, mbox_cmd_type, param, data); + mutex_unlock(&isst_hash_lock); + + return ret; +} +EXPORT_SYMBOL_GPL(isst_store_cmd); + +static void isst_mbox_resume_command(struct isst_if_cmd_cb *cb, + struct isst_cmd *sst_cmd) +{ + struct isst_if_mbox_cmd mbox_cmd; + int wr_only; + + mbox_cmd.command = (sst_cmd->cmd & GENMASK_ULL(31, 16)) >> 16; + mbox_cmd.sub_command = sst_cmd->cmd & GENMASK_ULL(15, 0); + mbox_cmd.parameter = sst_cmd->param; + mbox_cmd.req_data = sst_cmd->data; + mbox_cmd.logical_cpu = sst_cmd->cpu; + (cb->cmd_callback)((u8 *)&mbox_cmd, &wr_only, 1); +} + +/** + * isst_resume_common() - Process Resume request + * + * On resume replay all mailbox commands and MSRs. + * + * Return: None. + */ +void isst_resume_common(void) +{ + struct isst_cmd *sst_cmd; + int i; + + hash_for_each(isst_hash, i, sst_cmd, hnode) { + struct isst_if_cmd_cb *cb; + + if (sst_cmd->mbox_cmd_type) { + cb = &punit_callbacks[ISST_IF_DEV_MBOX]; + if (cb->registered) + isst_mbox_resume_command(cb, sst_cmd); + } else { + wrmsrl_safe_on_cpu(sst_cmd->cpu, sst_cmd->cmd, + sst_cmd->data); + } + } +} +EXPORT_SYMBOL_GPL(isst_resume_common); + +static void isst_restore_msr_local(int cpu) +{ + struct isst_cmd *sst_cmd; + int i; + + mutex_lock(&isst_hash_lock); + for (i = 0; i < ARRAY_SIZE(punit_msr_white_list); ++i) { + if (!punit_msr_white_list[i]) + break; + + hash_for_each_possible(isst_hash, sst_cmd, hnode, + punit_msr_white_list[i]) { + if (!sst_cmd->mbox_cmd_type && sst_cmd->cpu == cpu) + wrmsrl_safe(sst_cmd->cmd, sst_cmd->data); + } + } + mutex_unlock(&isst_hash_lock); +} + +/** + * isst_if_mbox_cmd_invalid() - Check invalid mailbox commands + * @cmd: Pointer to the command structure to verify. + * + * Invalid command to PUNIT to may result in instability of the platform. + * This function has a whitelist of commands, which are allowed. + * + * Return: Return true if the command is invalid, else false. + */ +bool isst_if_mbox_cmd_invalid(struct isst_if_mbox_cmd *cmd) +{ + int i; + + if (cmd->logical_cpu >= nr_cpu_ids) + return true; + + for (i = 0; i < ARRAY_SIZE(isst_valid_cmds); ++i) { + if (cmd->command == isst_valid_cmds[i].cmd && + (cmd->sub_command >= isst_valid_cmds[i].sub_cmd_beg && + cmd->sub_command <= isst_valid_cmds[i].sub_cmd_end)) { + return false; + } + } + + return true; +} +EXPORT_SYMBOL_GPL(isst_if_mbox_cmd_invalid); + +/** + * isst_if_mbox_cmd_set_req() - Check mailbox command is a set request + * @cmd: Pointer to the command structure to verify. + * + * Check if the given mail box level is set request and not a get request. + * + * Return: Return true if the command is set_req, else false. + */ +bool isst_if_mbox_cmd_set_req(struct isst_if_mbox_cmd *cmd) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(isst_cmd_set_reqs); ++i) { + if (cmd->command == isst_cmd_set_reqs[i].cmd && + cmd->sub_command == isst_cmd_set_reqs[i].sub_cmd && + cmd->parameter == isst_cmd_set_reqs[i].param) { + return true; + } + } + + return false; +} +EXPORT_SYMBOL_GPL(isst_if_mbox_cmd_set_req); + +static int isst_if_get_platform_info(void __user *argp) +{ + struct isst_if_platform_info info; + + info.api_version = ISST_IF_API_VERSION, + info.driver_version = ISST_IF_DRIVER_VERSION, + info.max_cmds_per_ioctl = ISST_IF_CMD_LIMIT, + info.mbox_supported = punit_callbacks[ISST_IF_DEV_MBOX].registered; + info.mmio_supported = punit_callbacks[ISST_IF_DEV_MMIO].registered; + + if (copy_to_user(argp, &info, sizeof(info))) + return -EFAULT; + + return 0; +} + + +struct isst_if_cpu_info { + /* For BUS 0 and BUS 1 only, which we need for PUNIT interface */ + int bus_info[2]; + int punit_cpu_id; +}; + +static struct isst_if_cpu_info *isst_cpu_info; + +/** + * isst_if_get_pci_dev() - Get the PCI device instance for a CPU + * @cpu: Logical CPU number. + * @bus_number: The bus number assigned by the hardware. + * @dev: The device number assigned by the hardware. + * @fn: The function number assigned by the hardware. + * + * Using cached bus information, find out the PCI device for a bus number, + * device and function. + * + * Return: Return pci_dev pointer or NULL. + */ +struct pci_dev *isst_if_get_pci_dev(int cpu, int bus_no, int dev, int fn) +{ + int bus_number; + + if (bus_no < 0 || bus_no > 1 || cpu < 0 || cpu >= nr_cpu_ids || + cpu >= num_possible_cpus()) + return NULL; + + bus_number = isst_cpu_info[cpu].bus_info[bus_no]; + if (bus_number < 0) + return NULL; + + return pci_get_domain_bus_and_slot(0, bus_number, PCI_DEVFN(dev, fn)); +} +EXPORT_SYMBOL_GPL(isst_if_get_pci_dev); + +static int isst_if_cpu_online(unsigned int cpu) +{ + u64 data; + int ret; + + ret = rdmsrl_safe(MSR_CPU_BUS_NUMBER, &data); + if (ret) { + /* This is not a fatal error on MSR mailbox only I/F */ + isst_cpu_info[cpu].bus_info[0] = -1; + isst_cpu_info[cpu].bus_info[1] = -1; + } else { + isst_cpu_info[cpu].bus_info[0] = data & 0xff; + isst_cpu_info[cpu].bus_info[1] = (data >> 8) & 0xff; + } + + ret = rdmsrl_safe(MSR_THREAD_ID_INFO, &data); + if (ret) { + isst_cpu_info[cpu].punit_cpu_id = -1; + return ret; + } + isst_cpu_info[cpu].punit_cpu_id = data; + + isst_restore_msr_local(cpu); + + return 0; +} + +static int isst_if_online_id; + +static int isst_if_cpu_info_init(void) +{ + int ret; + + isst_cpu_info = kcalloc(num_possible_cpus(), + sizeof(*isst_cpu_info), + GFP_KERNEL); + if (!isst_cpu_info) + return -ENOMEM; + + ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, + "platform/x86/isst-if:online", + isst_if_cpu_online, NULL); + if (ret < 0) { + kfree(isst_cpu_info); + return ret; + } + + isst_if_online_id = ret; + + return 0; +} + +static void isst_if_cpu_info_exit(void) +{ + cpuhp_remove_state(isst_if_online_id); + kfree(isst_cpu_info); +}; + +static long isst_if_proc_phyid_req(u8 *cmd_ptr, int *write_only, int resume) +{ + struct isst_if_cpu_map *cpu_map; + + cpu_map = (struct isst_if_cpu_map *)cmd_ptr; + if (cpu_map->logical_cpu >= nr_cpu_ids || + cpu_map->logical_cpu >= num_possible_cpus()) + return -EINVAL; + + *write_only = 0; + cpu_map->physical_cpu = isst_cpu_info[cpu_map->logical_cpu].punit_cpu_id; + + return 0; +} + +static bool match_punit_msr_white_list(int msr) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(punit_msr_white_list); ++i) { + if (punit_msr_white_list[i] == msr) + return true; + } + + return false; +} + +static long isst_if_msr_cmd_req(u8 *cmd_ptr, int *write_only, int resume) +{ + struct isst_if_msr_cmd *msr_cmd; + int ret; + + msr_cmd = (struct isst_if_msr_cmd *)cmd_ptr; + + if (!match_punit_msr_white_list(msr_cmd->msr)) + return -EINVAL; + + if (msr_cmd->logical_cpu >= nr_cpu_ids) + return -EINVAL; + + if (msr_cmd->read_write) { + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + ret = wrmsrl_safe_on_cpu(msr_cmd->logical_cpu, + msr_cmd->msr, + msr_cmd->data); + *write_only = 1; + if (!ret && !resume) + ret = isst_store_cmd(0, msr_cmd->msr, + msr_cmd->logical_cpu, + 0, 0, msr_cmd->data); + } else { + u64 data; + + ret = rdmsrl_safe_on_cpu(msr_cmd->logical_cpu, + msr_cmd->msr, &data); + if (!ret) { + msr_cmd->data = data; + *write_only = 0; + } + } + + + return ret; +} + +static long isst_if_exec_multi_cmd(void __user *argp, struct isst_if_cmd_cb *cb) +{ + unsigned char __user *ptr; + u32 cmd_count; + u8 *cmd_ptr; + long ret; + int i; + + /* Each multi command has u32 command count as the first field */ + if (copy_from_user(&cmd_count, argp, sizeof(cmd_count))) + return -EFAULT; + + if (!cmd_count || cmd_count > ISST_IF_CMD_LIMIT) + return -EINVAL; + + cmd_ptr = kmalloc(cb->cmd_size, GFP_KERNEL); + if (!cmd_ptr) + return -ENOMEM; + + /* cb->offset points to start of the command after the command count */ + ptr = argp + cb->offset; + + for (i = 0; i < cmd_count; ++i) { + int wr_only; + + if (signal_pending(current)) { + ret = -EINTR; + break; + } + + if (copy_from_user(cmd_ptr, ptr, cb->cmd_size)) { + ret = -EFAULT; + break; + } + + ret = cb->cmd_callback(cmd_ptr, &wr_only, 0); + if (ret) + break; + + if (!wr_only && copy_to_user(ptr, cmd_ptr, cb->cmd_size)) { + ret = -EFAULT; + break; + } + + ptr += cb->cmd_size; + } + + kfree(cmd_ptr); + + return i ? i : ret; +} + +static long isst_if_def_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + void __user *argp = (void __user *)arg; + struct isst_if_cmd_cb cmd_cb; + struct isst_if_cmd_cb *cb; + long ret = -ENOTTY; + + switch (cmd) { + case ISST_IF_GET_PLATFORM_INFO: + ret = isst_if_get_platform_info(argp); + break; + case ISST_IF_GET_PHY_ID: + cmd_cb.cmd_size = sizeof(struct isst_if_cpu_map); + cmd_cb.offset = offsetof(struct isst_if_cpu_maps, cpu_map); + cmd_cb.cmd_callback = isst_if_proc_phyid_req; + ret = isst_if_exec_multi_cmd(argp, &cmd_cb); + break; + case ISST_IF_IO_CMD: + cb = &punit_callbacks[ISST_IF_DEV_MMIO]; + if (cb->registered) + ret = isst_if_exec_multi_cmd(argp, cb); + break; + case ISST_IF_MBOX_COMMAND: + cb = &punit_callbacks[ISST_IF_DEV_MBOX]; + if (cb->registered) + ret = isst_if_exec_multi_cmd(argp, cb); + break; + case ISST_IF_MSR_COMMAND: + cmd_cb.cmd_size = sizeof(struct isst_if_msr_cmd); + cmd_cb.offset = offsetof(struct isst_if_msr_cmds, msr_cmd); + cmd_cb.cmd_callback = isst_if_msr_cmd_req; + ret = isst_if_exec_multi_cmd(argp, &cmd_cb); + break; + default: + break; + } + + return ret; +} + +static DEFINE_MUTEX(punit_misc_dev_lock); +static int misc_usage_count; +static int misc_device_ret; +static int misc_device_open; + +static int isst_if_open(struct inode *inode, struct file *file) +{ + int i, ret = 0; + + /* Fail open, if a module is going away */ + mutex_lock(&punit_misc_dev_lock); + for (i = 0; i < ISST_IF_DEV_MAX; ++i) { + struct isst_if_cmd_cb *cb = &punit_callbacks[i]; + + if (cb->registered && !try_module_get(cb->owner)) { + ret = -ENODEV; + break; + } + } + if (ret) { + int j; + + for (j = 0; j < i; ++j) { + struct isst_if_cmd_cb *cb; + + cb = &punit_callbacks[j]; + if (cb->registered) + module_put(cb->owner); + } + } else { + misc_device_open++; + } + mutex_unlock(&punit_misc_dev_lock); + + return ret; +} + +static int isst_if_relase(struct inode *inode, struct file *f) +{ + int i; + + mutex_lock(&punit_misc_dev_lock); + misc_device_open--; + for (i = 0; i < ISST_IF_DEV_MAX; ++i) { + struct isst_if_cmd_cb *cb = &punit_callbacks[i]; + + if (cb->registered) + module_put(cb->owner); + } + mutex_unlock(&punit_misc_dev_lock); + + return 0; +} + +static const struct file_operations isst_if_char_driver_ops = { + .open = isst_if_open, + .unlocked_ioctl = isst_if_def_ioctl, + .release = isst_if_relase, +}; + +static struct miscdevice isst_if_char_driver = { + .minor = MISC_DYNAMIC_MINOR, + .name = "isst_interface", + .fops = &isst_if_char_driver_ops, +}; + +/** + * isst_if_cdev_register() - Register callback for IOCTL + * @device_type: The device type this callback handling. + * @cb: Callback structure. + * + * This function registers a callback to device type. On very first call + * it will register a misc device, which is used for user kernel interface. + * Other calls simply increment ref count. Registry will fail, if the user + * already opened misc device for operation. Also if the misc device + * creation failed, then it will not try again and all callers will get + * failure code. + * + * Return: Return the return value from the misc creation device or -EINVAL + * for unsupported device type. + */ +int isst_if_cdev_register(int device_type, struct isst_if_cmd_cb *cb) +{ + if (misc_device_ret) + return misc_device_ret; + + if (device_type >= ISST_IF_DEV_MAX) + return -EINVAL; + + mutex_lock(&punit_misc_dev_lock); + if (misc_device_open) { + mutex_unlock(&punit_misc_dev_lock); + return -EAGAIN; + } + if (!misc_usage_count) { + int ret; + + misc_device_ret = misc_register(&isst_if_char_driver); + if (misc_device_ret) + goto unlock_exit; + + ret = isst_if_cpu_info_init(); + if (ret) { + misc_deregister(&isst_if_char_driver); + misc_device_ret = ret; + goto unlock_exit; + } + } + memcpy(&punit_callbacks[device_type], cb, sizeof(*cb)); + punit_callbacks[device_type].registered = 1; + misc_usage_count++; +unlock_exit: + mutex_unlock(&punit_misc_dev_lock); + + return misc_device_ret; +} +EXPORT_SYMBOL_GPL(isst_if_cdev_register); + +/** + * isst_if_cdev_unregister() - Unregister callback for IOCTL + * @device_type: The device type to unregister. + * + * This function unregisters the previously registered callback. If this + * is the last callback unregistering, then misc device is removed. + * + * Return: None. + */ +void isst_if_cdev_unregister(int device_type) +{ + mutex_lock(&punit_misc_dev_lock); + misc_usage_count--; + punit_callbacks[device_type].registered = 0; + if (device_type == ISST_IF_DEV_MBOX) + isst_delete_hash(); + if (!misc_usage_count && !misc_device_ret) { + misc_deregister(&isst_if_char_driver); + isst_if_cpu_info_exit(); + } + mutex_unlock(&punit_misc_dev_lock); +} +EXPORT_SYMBOL_GPL(isst_if_cdev_unregister); + +MODULE_LICENSE("GPL v2"); |