drivers/iommu/intel-pasid.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /**
   3  * intel-pasid.c - PASID idr, table and entry manipulation
   4  *
   5  * Copyright (C) 2018 Intel Corporation
   6  *
   7  * Author: Lu Baolu <baolu.lu@linux.intel.com>
   8  */
   9
  10 #define pr_fmt(fmt)     "DMAR: " fmt
  11
  12 #include <linux/dmar.h>
  13 #include <linux/intel-iommu.h>
  14 #include <linux/iommu.h>
  15 #include <linux/memory.h>
  16 #include <linux/pci.h>
  17 #include <linux/pci-ats.h>
  18 #include <linux/spinlock.h>
  19
  20 #include "intel-pasid.h"
  21
  22 /*
  23  * Intel IOMMU system wide PASID name space:
  24  */
  25 static DEFINE_SPINLOCK(pasid_lock);
  26 u32 intel_pasid_max_id = PASID_MAX;
  27 static DEFINE_IDR(pasid_idr);
  28
  29 int intel_pasid_alloc_id(void *ptr, int start, int end, gfp_t gfp)
  30 {
  31         int ret, min, max;
  32
  33         min = max_t(int, start, PASID_MIN);
  34         max = min_t(int, end, intel_pasid_max_id);
  35
  36         WARN_ON(in_interrupt());
  37         idr_preload(gfp);
  38         spin_lock(&pasid_lock);
  39         ret = idr_alloc(&pasid_idr, ptr, min, max, GFP_ATOMIC);
  40         spin_unlock(&pasid_lock);
  41         idr_preload_end();
  42
  43         return ret;
  44 }
  45
  46 void intel_pasid_free_id(int pasid)
  47 {
  48         spin_lock(&pasid_lock);
  49         idr_remove(&pasid_idr, pasid);
  50         spin_unlock(&pasid_lock);
  51 }
  52
  53 void *intel_pasid_lookup_id(int pasid)
  54 {
  55         void *p;
  56
  57         spin_lock(&pasid_lock);
  58         p = idr_find(&pasid_idr, pasid);
  59         spin_unlock(&pasid_lock);
  60
  61         return p;
  62 }
  63
  64 /*
  65  * Per device pasid table management:
  66  */
  67 static inline void
  68 device_attach_pasid_table(struct device_domain_info *info,
  69                           struct pasid_table *pasid_table)
  70 {
  71         info->pasid_table = pasid_table;
  72         list_add(&info->table, &pasid_table->dev);
  73 }
  74
  75 static inline void
  76 device_detach_pasid_table(struct device_domain_info *info,
  77                           struct pasid_table *pasid_table)
  78 {
  79         info->pasid_table = NULL;
  80         list_del(&info->table);
  81 }
  82
  83 struct pasid_table_opaque {
  84         struct pasid_table      **pasid_table;
  85         int                     segment;
  86         int                     bus;
  87         int                     devfn;
  88 };
  89
  90 static int search_pasid_table(struct device_domain_info *info, void *opaque)
  91 {
  92         struct pasid_table_opaque *data = opaque;
  93
  94         if (info->iommu->segment == data->segment &&
  95             info->bus == data->bus &&
  96             info->devfn == data->devfn &&
  97             info->pasid_table) {
  98                 *data->pasid_table = info->pasid_table;
  99                 return 1;
 100         }
 101
 102         return 0;
 103 }
 104
 105 static int get_alias_pasid_table(struct pci_dev *pdev, u16 alias, void *opaque)
 106 {
 107         struct pasid_table_opaque *data = opaque;
 108
 109         data->segment = pci_domain_nr(pdev->bus);
 110         data->bus = PCI_BUS_NUM(alias);
 111         data->devfn = alias & 0xff;
 112
 113         return for_each_device_domain(&search_pasid_table, data);
 114 }
 115
 116 /*
 117  * Allocate a pasid table for @dev. It should be called in a
 118  * single-thread context.
 119  */
 120 int intel_pasid_alloc_table(struct device *dev)
 121 {
 122         struct device_domain_info *info;
 123         struct pasid_table *pasid_table;
 124         struct pasid_table_opaque data;
 125         struct page *pages;
 126         size_t size, count;
 127         int ret, order;
 128
 129         info = dev->archdata.iommu;
 130         if (WARN_ON(!info || !dev_is_pci(dev) ||
 131                     !info->pasid_supported || info->pasid_table))
 132                 return -EINVAL;
 133
 134         /* DMA alias device already has a pasid table, use it: */
 135         data.pasid_table = &pasid_table;
 136         ret = pci_for_each_dma_alias(to_pci_dev(dev),
 137                                      &get_alias_pasid_table, &data);
 138         if (ret)
 139                 goto attach_out;
 140
 141         pasid_table = kzalloc(sizeof(*pasid_table), GFP_ATOMIC);
 142         if (!pasid_table)
 143                 return -ENOMEM;
 144         INIT_LIST_HEAD(&pasid_table->dev);
 145
 146         size = sizeof(struct pasid_entry);
 147         count = min_t(int, pci_max_pasids(to_pci_dev(dev)), intel_pasid_max_id);
 148         order = get_order(size * count);
 149         pages = alloc_pages_node(info->iommu->node,
 150                                  GFP_ATOMIC | __GFP_ZERO,
 151                                  order);
 152         if (!pages)
 153                 return -ENOMEM;
 154
 155         pasid_table->table = page_address(pages);
 156         pasid_table->order = order;
 157         pasid_table->max_pasid = count;
 158
 159 attach_out:
 160         device_attach_pasid_table(info, pasid_table);
 161
 162         return 0;
 163 }
 164
 165 void intel_pasid_free_table(struct device *dev)
 166 {
 167         struct device_domain_info *info;
 168         struct pasid_table *pasid_table;
 169
 170         info = dev->archdata.iommu;
 171         if (!info || !dev_is_pci(dev) ||
 172             !info->pasid_supported || !info->pasid_table)
 173                 return;
 174
 175         pasid_table = info->pasid_table;
 176         device_detach_pasid_table(info, pasid_table);
 177
 178         if (!list_empty(&pasid_table->dev))
 179                 return;
 180
 181         free_pages((unsigned long)pasid_table->table, pasid_table->order);
 182         kfree(pasid_table);
 183 }
 184
 185 struct pasid_table *intel_pasid_get_table(struct device *dev)
 186 {
 187         struct device_domain_info *info;
 188
 189         info = dev->archdata.iommu;
 190         if (!info)
 191                 return NULL;
 192
 193         return info->pasid_table;
 194 }
 195
 196 int intel_pasid_get_dev_max_id(struct device *dev)
 197 {
 198         struct device_domain_info *info;
 199
 200         info = dev->archdata.iommu;
 201         if (!info || !info->pasid_table)
 202                 return 0;
 203
 204         return info->pasid_table->max_pasid;
 205 }
 206
 207 struct pasid_entry *intel_pasid_get_entry(struct device *dev, int pasid)
 208 {
 209         struct pasid_table *pasid_table;
 210         struct pasid_entry *entries;
 211
 212         pasid_table = intel_pasid_get_table(dev);
 213         if (WARN_ON(!pasid_table || pasid < 0 ||
 214                     pasid >= intel_pasid_get_dev_max_id(dev)))
 215                 return NULL;
 216
 217         entries = pasid_table->table;
 218
 219         return &entries[pasid];
 220 }
 221
 222 /*
 223  * Interfaces for PASID table entry manipulation:
 224  */
 225 static inline void pasid_clear_entry(struct pasid_entry *pe)
 226 {
 227         WRITE_ONCE(pe->val, 0);
 228 }
 229
 230 void intel_pasid_clear_entry(struct device *dev, int pasid)
 231 {
 232         struct pasid_entry *pe;
 233
 234         pe = intel_pasid_get_entry(dev, pasid);
 235         if (WARN_ON(!pe))
 236                 return;
 237
 238         pasid_clear_entry(pe);
 239 }