linux/drivers/platform/x86/intel/speed_select_if/isst_if_mmio.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Intel Speed Select Interface: MMIO Interface
   4 * Copyright (c) 2019, Intel Corporation.
   5 * All rights reserved.
   6 *
   7 * Author: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
   8 */
   9
  10#include <linux/module.h>
  11#include <linux/pci.h>
  12#include <linux/sched/signal.h>
  13#include <linux/uaccess.h>
  14#include <uapi/linux/isst_if.h>
  15
  16#include "isst_if_common.h"
  17
  18struct isst_mmio_range {
  19        int beg;
  20        int end;
  21};
  22
  23static struct isst_mmio_range mmio_range_devid_0[] = {
  24        {0x04, 0x14},
  25        {0x20, 0xD0},
  26};
  27
  28static struct isst_mmio_range mmio_range_devid_1[] = {
  29        {0x04, 0x14},
  30        {0x20, 0x11C},
  31};
  32
  33struct isst_if_device {
  34        void __iomem *punit_mmio;
  35        u32 range_0[5];
  36        u32 range_1[64];
  37        struct isst_mmio_range *mmio_range;
  38        struct mutex mutex;
  39};
  40
  41static long isst_if_mmio_rd_wr(u8 *cmd_ptr, int *write_only, int resume)
  42{
  43        struct isst_if_device *punit_dev;
  44        struct isst_if_io_reg *io_reg;
  45        struct pci_dev *pdev;
  46
  47        io_reg = (struct isst_if_io_reg *)cmd_ptr;
  48
  49        if (io_reg->reg % 4)
  50                return -EINVAL;
  51
  52        if (io_reg->read_write && !capable(CAP_SYS_ADMIN))
  53                return -EPERM;
  54
  55        pdev = isst_if_get_pci_dev(io_reg->logical_cpu, 0, 0, 1);
  56        if (!pdev)
  57                return -EINVAL;
  58
  59        punit_dev = pci_get_drvdata(pdev);
  60        if (!punit_dev)
  61                return -EINVAL;
  62
  63        if (io_reg->reg < punit_dev->mmio_range[0].beg ||
  64            io_reg->reg > punit_dev->mmio_range[1].end)
  65                return -EINVAL;
  66
  67        /*
  68         * Ensure that operation is complete on a PCI device to avoid read
  69         * write race by using per PCI device mutex.
  70         */
  71        mutex_lock(&punit_dev->mutex);
  72        if (io_reg->read_write) {
  73                writel(io_reg->value, punit_dev->punit_mmio+io_reg->reg);
  74                *write_only = 1;
  75        } else {
  76                io_reg->value = readl(punit_dev->punit_mmio+io_reg->reg);
  77                *write_only = 0;
  78        }
  79        mutex_unlock(&punit_dev->mutex);
  80
  81        return 0;
  82}
  83
  84static const struct pci_device_id isst_if_ids[] = {
  85        { PCI_DEVICE_DATA(INTEL, RAPL_PRIO_DEVID_0, &mmio_range_devid_0)},
  86        { PCI_DEVICE_DATA(INTEL, RAPL_PRIO_DEVID_1, &mmio_range_devid_1)},
  87        { 0 },
  88};
  89MODULE_DEVICE_TABLE(pci, isst_if_ids);
  90
  91static int isst_if_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
  92{
  93        struct isst_if_device *punit_dev;
  94        struct isst_if_cmd_cb cb;
  95        u32 mmio_base, pcu_base;
  96        u64 base_addr;
  97        int ret;
  98
  99        punit_dev = devm_kzalloc(&pdev->dev, sizeof(*punit_dev), GFP_KERNEL);
 100        if (!punit_dev)
 101                return -ENOMEM;
 102
 103        ret = pcim_enable_device(pdev);
 104        if (ret)
 105                return ret;
 106
 107        ret = pci_read_config_dword(pdev, 0xD0, &mmio_base);
 108        if (ret)
 109                return ret;
 110
 111        ret = pci_read_config_dword(pdev, 0xFC, &pcu_base);
 112        if (ret)
 113                return ret;
 114
 115        pcu_base &= GENMASK(10, 0);
 116        base_addr = (u64)mmio_base << 23 | (u64) pcu_base << 12;
 117        punit_dev->punit_mmio = devm_ioremap(&pdev->dev, base_addr, 256);
 118        if (!punit_dev->punit_mmio)
 119                return -ENOMEM;
 120
 121        mutex_init(&punit_dev->mutex);
 122        pci_set_drvdata(pdev, punit_dev);
 123        punit_dev->mmio_range = (struct isst_mmio_range *) ent->driver_data;
 124
 125        memset(&cb, 0, sizeof(cb));
 126        cb.cmd_size = sizeof(struct isst_if_io_reg);
 127        cb.offset = offsetof(struct isst_if_io_regs, io_reg);
 128        cb.cmd_callback = isst_if_mmio_rd_wr;
 129        cb.owner = THIS_MODULE;
 130        ret = isst_if_cdev_register(ISST_IF_DEV_MMIO, &cb);
 131        if (ret)
 132                mutex_destroy(&punit_dev->mutex);
 133
 134        return ret;
 135}
 136
 137static void isst_if_remove(struct pci_dev *pdev)
 138{
 139        struct isst_if_device *punit_dev;
 140
 141        punit_dev = pci_get_drvdata(pdev);
 142        isst_if_cdev_unregister(ISST_IF_DEV_MMIO);
 143        mutex_destroy(&punit_dev->mutex);
 144}
 145
 146static int __maybe_unused isst_if_suspend(struct device *device)
 147{
 148        struct isst_if_device *punit_dev = dev_get_drvdata(device);
 149        int i;
 150
 151        for (i = 0; i < ARRAY_SIZE(punit_dev->range_0); ++i)
 152                punit_dev->range_0[i] = readl(punit_dev->punit_mmio +
 153                                                punit_dev->mmio_range[0].beg + 4 * i);
 154        for (i = 0; i < ARRAY_SIZE(punit_dev->range_1); ++i) {
 155                u32 addr;
 156
 157                addr = punit_dev->mmio_range[1].beg + 4 * i;
 158                if (addr > punit_dev->mmio_range[1].end)
 159                        break;
 160                punit_dev->range_1[i] = readl(punit_dev->punit_mmio + addr);
 161        }
 162
 163        return 0;
 164}
 165
 166static int __maybe_unused isst_if_resume(struct device *device)
 167{
 168        struct isst_if_device *punit_dev = dev_get_drvdata(device);
 169        int i;
 170
 171        for (i = 0; i < ARRAY_SIZE(punit_dev->range_0); ++i)
 172                writel(punit_dev->range_0[i], punit_dev->punit_mmio +
 173                                                punit_dev->mmio_range[0].beg + 4 * i);
 174        for (i = 0; i < ARRAY_SIZE(punit_dev->range_1); ++i) {
 175                u32 addr;
 176
 177                addr = punit_dev->mmio_range[1].beg + 4 * i;
 178                if (addr > punit_dev->mmio_range[1].end)
 179                        break;
 180
 181                writel(punit_dev->range_1[i], punit_dev->punit_mmio + addr);
 182        }
 183
 184        return 0;
 185}
 186
 187static SIMPLE_DEV_PM_OPS(isst_if_pm_ops, isst_if_suspend, isst_if_resume);
 188
 189static struct pci_driver isst_if_pci_driver = {
 190        .name                   = "isst_if_pci",
 191        .id_table               = isst_if_ids,
 192        .probe                  = isst_if_probe,
 193        .remove                 = isst_if_remove,
 194        .driver.pm              = &isst_if_pm_ops,
 195};
 196
 197module_pci_driver(isst_if_pci_driver);
 198
 199MODULE_LICENSE("GPL v2");
 200MODULE_DESCRIPTION("Intel speed select interface mmio driver");
 201