// SPDX-License-Identifier: GPL-2.0
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/*
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* Intel Speed Select Interface: Common functions
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* Copyright (c) 2019, Intel Corporation.
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* All rights reserved.
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*
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* Author: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
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*/
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#include <linux/cpufeature.h>
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#include <linux/cpuhotplug.h>
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#include <linux/fs.h>
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#include <linux/hashtable.h>
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#include <linux/miscdevice.h>
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#include <linux/module.h>
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#include <linux/pci.h>
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#include <linux/sched/signal.h>
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#include <linux/slab.h>
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#include <linux/uaccess.h>
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#include <uapi/linux/isst_if.h>
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#include "isst_if_common.h"
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#define MSR_THREAD_ID_INFO 0x53
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#define MSR_CPU_BUS_NUMBER 0x128
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static struct isst_if_cmd_cb punit_callbacks[ISST_IF_DEV_MAX];
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static int punit_msr_white_list[] = {
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MSR_TURBO_RATIO_LIMIT,
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MSR_CONFIG_TDP_CONTROL,
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MSR_TURBO_RATIO_LIMIT1,
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MSR_TURBO_RATIO_LIMIT2,
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};
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struct isst_valid_cmd_ranges {
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u16 cmd;
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u16 sub_cmd_beg;
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u16 sub_cmd_end;
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};
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struct isst_cmd_set_req_type {
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u16 cmd;
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u16 sub_cmd;
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u16 param;
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};
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static const struct isst_valid_cmd_ranges isst_valid_cmds[] = {
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{0xD0, 0x00, 0x03},
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{0x7F, 0x00, 0x0B},
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{0x7F, 0x10, 0x12},
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{0x7F, 0x20, 0x23},
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{0x94, 0x03, 0x03},
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{0x95, 0x03, 0x03},
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};
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static const struct isst_cmd_set_req_type isst_cmd_set_reqs[] = {
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{0xD0, 0x00, 0x08},
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{0xD0, 0x01, 0x08},
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{0xD0, 0x02, 0x08},
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{0xD0, 0x03, 0x08},
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{0x7F, 0x02, 0x00},
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{0x7F, 0x08, 0x00},
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{0x95, 0x03, 0x03},
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};
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struct isst_cmd {
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struct hlist_node hnode;
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u64 data;
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u32 cmd;
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int cpu;
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int mbox_cmd_type;
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u32 param;
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};
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static DECLARE_HASHTABLE(isst_hash, 8);
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static DEFINE_MUTEX(isst_hash_lock);
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static int isst_store_new_cmd(int cmd, u32 cpu, int mbox_cmd_type, u32 param,
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u32 data)
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{
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struct isst_cmd *sst_cmd;
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sst_cmd = kmalloc(sizeof(*sst_cmd), GFP_KERNEL);
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if (!sst_cmd)
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return -ENOMEM;
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sst_cmd->cpu = cpu;
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sst_cmd->cmd = cmd;
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sst_cmd->mbox_cmd_type = mbox_cmd_type;
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sst_cmd->param = param;
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sst_cmd->data = data;
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hash_add(isst_hash, &sst_cmd->hnode, sst_cmd->cmd);
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return 0;
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}
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static void isst_delete_hash(void)
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{
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struct isst_cmd *sst_cmd;
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struct hlist_node *tmp;
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int i;
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hash_for_each_safe(isst_hash, i, tmp, sst_cmd, hnode) {
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hash_del(&sst_cmd->hnode);
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kfree(sst_cmd);
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}
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}
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/**
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* isst_store_cmd() - Store command to a hash table
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* @cmd: Mailbox command.
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* @sub_cmd: Mailbox sub-command or MSR id.
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* @mbox_cmd_type: Mailbox or MSR command.
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* @param: Mailbox parameter.
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* @data: Mailbox request data or MSR data.
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*
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* Stores the command to a hash table if there is no such command already
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* stored. If already stored update the latest parameter and data for the
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* command.
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*
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* Return: Return result of store to hash table, 0 for success, others for
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* failure.
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*/
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int isst_store_cmd(int cmd, int sub_cmd, u32 cpu, int mbox_cmd_type,
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u32 param, u64 data)
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{
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struct isst_cmd *sst_cmd;
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int full_cmd, ret;
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full_cmd = (cmd & GENMASK_ULL(15, 0)) << 16;
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full_cmd |= (sub_cmd & GENMASK_ULL(15, 0));
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mutex_lock(&isst_hash_lock);
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hash_for_each_possible(isst_hash, sst_cmd, hnode, full_cmd) {
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if (sst_cmd->cmd == full_cmd && sst_cmd->cpu == cpu &&
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sst_cmd->mbox_cmd_type == mbox_cmd_type) {
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sst_cmd->param = param;
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sst_cmd->data = data;
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mutex_unlock(&isst_hash_lock);
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return 0;
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}
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}
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ret = isst_store_new_cmd(full_cmd, cpu, mbox_cmd_type, param, data);
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mutex_unlock(&isst_hash_lock);
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return ret;
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}
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EXPORT_SYMBOL_GPL(isst_store_cmd);
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static void isst_mbox_resume_command(struct isst_if_cmd_cb *cb,
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struct isst_cmd *sst_cmd)
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{
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struct isst_if_mbox_cmd mbox_cmd;
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int wr_only;
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mbox_cmd.command = (sst_cmd->cmd & GENMASK_ULL(31, 16)) >> 16;
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mbox_cmd.sub_command = sst_cmd->cmd & GENMASK_ULL(15, 0);
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mbox_cmd.parameter = sst_cmd->param;
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mbox_cmd.req_data = sst_cmd->data;
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mbox_cmd.logical_cpu = sst_cmd->cpu;
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(cb->cmd_callback)((u8 *)&mbox_cmd, &wr_only, 1);
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}
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/**
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* isst_resume_common() - Process Resume request
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*
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* On resume replay all mailbox commands and MSRs.
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*
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* Return: None.
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*/
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void isst_resume_common(void)
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{
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struct isst_cmd *sst_cmd;
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int i;
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hash_for_each(isst_hash, i, sst_cmd, hnode) {
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struct isst_if_cmd_cb *cb;
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if (sst_cmd->mbox_cmd_type) {
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cb = &punit_callbacks[ISST_IF_DEV_MBOX];
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if (cb->registered)
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isst_mbox_resume_command(cb, sst_cmd);
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} else {
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wrmsrl_safe_on_cpu(sst_cmd->cpu, sst_cmd->cmd,
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sst_cmd->data);
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}
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}
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}
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EXPORT_SYMBOL_GPL(isst_resume_common);
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static void isst_restore_msr_local(int cpu)
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{
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struct isst_cmd *sst_cmd;
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int i;
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mutex_lock(&isst_hash_lock);
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for (i = 0; i < ARRAY_SIZE(punit_msr_white_list); ++i) {
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if (!punit_msr_white_list[i])
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break;
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hash_for_each_possible(isst_hash, sst_cmd, hnode,
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punit_msr_white_list[i]) {
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if (!sst_cmd->mbox_cmd_type && sst_cmd->cpu == cpu)
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wrmsrl_safe(sst_cmd->cmd, sst_cmd->data);
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}
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}
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mutex_unlock(&isst_hash_lock);
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}
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/**
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* isst_if_mbox_cmd_invalid() - Check invalid mailbox commands
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* @cmd: Pointer to the command structure to verify.
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*
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* Invalid command to PUNIT to may result in instability of the platform.
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* This function has a whitelist of commands, which are allowed.
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*
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* Return: Return true if the command is invalid, else false.
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*/
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bool isst_if_mbox_cmd_invalid(struct isst_if_mbox_cmd *cmd)
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{
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int i;
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if (cmd->logical_cpu >= nr_cpu_ids)
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return true;
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for (i = 0; i < ARRAY_SIZE(isst_valid_cmds); ++i) {
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if (cmd->command == isst_valid_cmds[i].cmd &&
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(cmd->sub_command >= isst_valid_cmds[i].sub_cmd_beg &&
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cmd->sub_command <= isst_valid_cmds[i].sub_cmd_end)) {
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return false;
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}
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}
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return true;
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}
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EXPORT_SYMBOL_GPL(isst_if_mbox_cmd_invalid);
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/**
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* isst_if_mbox_cmd_set_req() - Check mailbox command is a set request
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* @cmd: Pointer to the command structure to verify.
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*
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* Check if the given mail box level is set request and not a get request.
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*
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* Return: Return true if the command is set_req, else false.
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*/
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bool isst_if_mbox_cmd_set_req(struct isst_if_mbox_cmd *cmd)
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{
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int i;
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for (i = 0; i < ARRAY_SIZE(isst_cmd_set_reqs); ++i) {
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if (cmd->command == isst_cmd_set_reqs[i].cmd &&
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cmd->sub_command == isst_cmd_set_reqs[i].sub_cmd &&
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cmd->parameter == isst_cmd_set_reqs[i].param) {
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return true;
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}
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}
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return false;
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}
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EXPORT_SYMBOL_GPL(isst_if_mbox_cmd_set_req);
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static int isst_if_get_platform_info(void __user *argp)
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{
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struct isst_if_platform_info info;
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info.api_version = ISST_IF_API_VERSION,
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info.driver_version = ISST_IF_DRIVER_VERSION,
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info.max_cmds_per_ioctl = ISST_IF_CMD_LIMIT,
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info.mbox_supported = punit_callbacks[ISST_IF_DEV_MBOX].registered;
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info.mmio_supported = punit_callbacks[ISST_IF_DEV_MMIO].registered;
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if (copy_to_user(argp, &info, sizeof(info)))
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return -EFAULT;
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return 0;
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}
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struct isst_if_cpu_info {
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/* For BUS 0 and BUS 1 only, which we need for PUNIT interface */
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int bus_info[2];
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int punit_cpu_id;
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};
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static struct isst_if_cpu_info *isst_cpu_info;
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/**
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* isst_if_get_pci_dev() - Get the PCI device instance for a CPU
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* @cpu: Logical CPU number.
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* @bus_number: The bus number assigned by the hardware.
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* @dev: The device number assigned by the hardware.
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* @fn: The function number assigned by the hardware.
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*
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* Using cached bus information, find out the PCI device for a bus number,
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* device and function.
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*
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* Return: Return pci_dev pointer or NULL.
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*/
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struct pci_dev *isst_if_get_pci_dev(int cpu, int bus_no, int dev, int fn)
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{
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int bus_number;
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if (bus_no < 0 || bus_no > 1 || cpu < 0 || cpu >= nr_cpu_ids ||
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cpu >= num_possible_cpus())
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return NULL;
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bus_number = isst_cpu_info[cpu].bus_info[bus_no];
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if (bus_number < 0)
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return NULL;
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return pci_get_domain_bus_and_slot(0, bus_number, PCI_DEVFN(dev, fn));
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}
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EXPORT_SYMBOL_GPL(isst_if_get_pci_dev);
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static int isst_if_cpu_online(unsigned int cpu)
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{
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u64 data;
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int ret;
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ret = rdmsrl_safe(MSR_CPU_BUS_NUMBER, &data);
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if (ret) {
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/* This is not a fatal error on MSR mailbox only I/F */
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isst_cpu_info[cpu].bus_info[0] = -1;
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isst_cpu_info[cpu].bus_info[1] = -1;
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} else {
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isst_cpu_info[cpu].bus_info[0] = data & 0xff;
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isst_cpu_info[cpu].bus_info[1] = (data >> 8) & 0xff;
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}
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ret = rdmsrl_safe(MSR_THREAD_ID_INFO, &data);
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if (ret) {
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isst_cpu_info[cpu].punit_cpu_id = -1;
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return ret;
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}
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isst_cpu_info[cpu].punit_cpu_id = data;
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isst_restore_msr_local(cpu);
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return 0;
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}
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static int isst_if_online_id;
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static int isst_if_cpu_info_init(void)
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{
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int ret;
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isst_cpu_info = kcalloc(num_possible_cpus(),
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sizeof(*isst_cpu_info),
|
GFP_KERNEL);
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if (!isst_cpu_info)
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return -ENOMEM;
|
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ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
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"platform/x86/isst-if:online",
|
isst_if_cpu_online, NULL);
|
if (ret < 0) {
|
kfree(isst_cpu_info);
|
return ret;
|
}
|
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isst_if_online_id = ret;
|
|
return 0;
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}
|
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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;
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*write_only = 0;
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cpu_map->physical_cpu = isst_cpu_info[cpu_map->logical_cpu].punit_cpu_id;
|
|
return 0;
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}
|
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static bool match_punit_msr_white_list(int msr)
|
{
|
int i;
|
|
for (i = 0; i < ARRAY_SIZE(punit_msr_white_list); ++i) {
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if (punit_msr_white_list[i] == msr)
|
return true;
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}
|
|
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;
|
}
|
|
/* Lock to prevent module registration when already opened by user space */
|
static DEFINE_MUTEX(punit_misc_dev_open_lock);
|
/* Lock to allow one share misc device for all ISST interace */
|
static DEFINE_MUTEX(punit_misc_dev_reg_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_open_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_open_lock);
|
|
return ret;
|
}
|
|
static int isst_if_relase(struct inode *inode, struct file *f)
|
{
|
int i;
|
|
mutex_lock(&punit_misc_dev_open_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_open_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,
|
};
|
|
static int isst_misc_reg(void)
|
{
|
mutex_lock(&punit_misc_dev_reg_lock);
|
if (misc_device_ret)
|
goto unlock_exit;
|
|
if (!misc_usage_count) {
|
misc_device_ret = isst_if_cpu_info_init();
|
if (misc_device_ret)
|
goto unlock_exit;
|
|
misc_device_ret = misc_register(&isst_if_char_driver);
|
if (misc_device_ret) {
|
isst_if_cpu_info_exit();
|
goto unlock_exit;
|
}
|
}
|
misc_usage_count++;
|
|
unlock_exit:
|
mutex_unlock(&punit_misc_dev_reg_lock);
|
|
return misc_device_ret;
|
}
|
|
static void isst_misc_unreg(void)
|
{
|
mutex_lock(&punit_misc_dev_reg_lock);
|
if (misc_usage_count)
|
misc_usage_count--;
|
if (!misc_usage_count && !misc_device_ret) {
|
misc_deregister(&isst_if_char_driver);
|
isst_if_cpu_info_exit();
|
}
|
mutex_unlock(&punit_misc_dev_reg_lock);
|
}
|
|
/**
|
* 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)
|
{
|
int ret;
|
|
if (device_type >= ISST_IF_DEV_MAX)
|
return -EINVAL;
|
|
mutex_lock(&punit_misc_dev_open_lock);
|
/* Device is already open, we don't want to add new callbacks */
|
if (misc_device_open) {
|
mutex_unlock(&punit_misc_dev_open_lock);
|
return -EAGAIN;
|
}
|
memcpy(&punit_callbacks[device_type], cb, sizeof(*cb));
|
punit_callbacks[device_type].registered = 1;
|
mutex_unlock(&punit_misc_dev_open_lock);
|
|
ret = isst_misc_reg();
|
if (ret) {
|
/*
|
* No need of mutex as the misc device register failed
|
* as no one can open device yet. Hence no contention.
|
*/
|
punit_callbacks[device_type].registered = 0;
|
return ret;
|
}
|
return 0;
|
}
|
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)
|
{
|
isst_misc_unreg();
|
mutex_lock(&punit_misc_dev_open_lock);
|
punit_callbacks[device_type].registered = 0;
|
if (device_type == ISST_IF_DEV_MBOX)
|
isst_delete_hash();
|
mutex_unlock(&punit_misc_dev_open_lock);
|
}
|
EXPORT_SYMBOL_GPL(isst_if_cdev_unregister);
|
|
MODULE_LICENSE("GPL v2");
|
