arch/x86/pci/sta2x11-fixup.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * DMA translation between STA2x11 AMBA memory mapping and the x86 memory mapping
   4  *
   5  * ST Microelectronics ConneXt (STA2X11/STA2X10)
   6  *
   7  * Copyright (c) 2010-2011 Wind River Systems, Inc.
   8  */
   9
  10 #include <linux/pci.h>
  11 #include <linux/pci_ids.h>
  12 #include <linux/export.h>
  13 #include <linux/list.h>
  14 #include <linux/dma-direct.h>
  15 #include <asm/iommu.h>
  16
  17 #define STA2X11_SWIOTLB_SIZE (4*1024*1024)
  18 extern int swiotlb_late_init_with_default_size(size_t default_size);
  19
  20 /*
  21  * We build a list of bus numbers that are under the ConneXt. The
  22  * main bridge hosts 4 busses, which are the 4 endpoints, in order.
  23  */
  24 #define STA2X11_NR_EP           4       /* 0..3 included */
  25 #define STA2X11_NR_FUNCS        8       /* 0..7 included */
  26 #define STA2X11_AMBA_SIZE       (512 << 20)
  27
  28 struct sta2x11_ahb_regs { /* saved during suspend */
  29         u32 base, pexlbase, pexhbase, crw;
  30 };
  31
  32 struct sta2x11_mapping {
  33         int is_suspended;
  34         struct sta2x11_ahb_regs regs[STA2X11_NR_FUNCS];
  35 };
  36
  37 struct sta2x11_instance {
  38         struct list_head list;
  39         int bus0;
  40         struct sta2x11_mapping map[STA2X11_NR_EP];
  41 };
  42
  43 static LIST_HEAD(sta2x11_instance_list);
  44
  45 /* At probe time, record new instances of this bridge (likely one only) */
  46 static void sta2x11_new_instance(struct pci_dev *pdev)
  47 {
  48         struct sta2x11_instance *instance;
  49
  50         instance = kzalloc(sizeof(*instance), GFP_ATOMIC);
  51         if (!instance)
  52                 return;
  53         /* This has a subordinate bridge, with 4 more-subordinate ones */
  54         instance->bus0 = pdev->subordinate->number + 1;
  55
  56         if (list_empty(&sta2x11_instance_list)) {
  57                 int size = STA2X11_SWIOTLB_SIZE;
  58                 /* First instance: register your own swiotlb area */
  59                 dev_info(&pdev->dev, "Using SWIOTLB (size %i)\n", size);
  60                 if (swiotlb_late_init_with_default_size(size))
  61                         dev_emerg(&pdev->dev, "init swiotlb failed\n");
  62         }
  63         list_add(&instance->list, &sta2x11_instance_list);
  64 }
  65 DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_STMICRO, 0xcc17, sta2x11_new_instance);
  66
  67 /*
  68  * Utility functions used in this file from below
  69  */
  70 static struct sta2x11_instance *sta2x11_pdev_to_instance(struct pci_dev *pdev)
  71 {
  72         struct sta2x11_instance *instance;
  73         int ep;
  74
  75         list_for_each_entry(instance, &sta2x11_instance_list, list) {
  76                 ep = pdev->bus->number - instance->bus0;
  77                 if (ep >= 0 && ep < STA2X11_NR_EP)
  78                         return instance;
  79         }
  80         return NULL;
  81 }
  82
  83 static int sta2x11_pdev_to_ep(struct pci_dev *pdev)
  84 {
  85         struct sta2x11_instance *instance;
  86
  87         instance = sta2x11_pdev_to_instance(pdev);
  88         if (!instance)
  89                 return -1;
  90
  91         return pdev->bus->number - instance->bus0;
  92 }
  93
  94 /* This is exported, as some devices need to access the MFD registers */
  95 struct sta2x11_instance *sta2x11_get_instance(struct pci_dev *pdev)
  96 {
  97         return sta2x11_pdev_to_instance(pdev);
  98 }
  99 EXPORT_SYMBOL(sta2x11_get_instance);
 100
 101 /* At setup time, we use our own ops if the device is a ConneXt one */
 102 static void sta2x11_setup_pdev(struct pci_dev *pdev)
 103 {
 104         struct sta2x11_instance *instance = sta2x11_pdev_to_instance(pdev);
 105
 106         if (!instance) /* either a sta2x11 bridge or another ST device */
 107                 return;
 108
 109         /* We must enable all devices as master, for audio DMA to work */
 110         pci_set_master(pdev);
 111 }
 112 DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, sta2x11_setup_pdev);
 113
 114 /*
 115  * At boot we must set up the mappings for the pcie-to-amba bridge.
 116  * It involves device access, and the same happens at suspend/resume time
 117  */
 118
 119 #define AHB_MAPB                0xCA4
 120 #define AHB_CRW(i)              (AHB_MAPB + 0  + (i) * 0x10)
 121 #define AHB_CRW_SZMASK                  0xfffffc00UL
 122 #define AHB_CRW_ENABLE                  (1 << 0)
 123 #define AHB_CRW_WTYPE_MEM               (2 << 1)
 124 #define AHB_CRW_ROE                     (1UL << 3)      /* Relax Order Ena */
 125 #define AHB_CRW_NSE                     (1UL << 4)      /* No Snoop Enable */
 126 #define AHB_BASE(i)             (AHB_MAPB + 4  + (i) * 0x10)
 127 #define AHB_PEXLBASE(i)         (AHB_MAPB + 8  + (i) * 0x10)
 128 #define AHB_PEXHBASE(i)         (AHB_MAPB + 12 + (i) * 0x10)
 129
 130 /* At probe time, enable mapping for each endpoint, using the pdev */
 131 static void sta2x11_map_ep(struct pci_dev *pdev)
 132 {
 133         struct sta2x11_instance *instance = sta2x11_pdev_to_instance(pdev);
 134         struct device *dev = &pdev->dev;
 135         u32 amba_base, max_amba_addr;
 136         int i;
 137
 138         if (!instance)
 139                 return;
 140
 141         pci_read_config_dword(pdev, AHB_BASE(0), &amba_base);
 142         max_amba_addr = amba_base + STA2X11_AMBA_SIZE - 1;
 143
 144         dev->dma_pfn_offset = PFN_DOWN(-amba_base);
 145
 146         dev->bus_dma_limit = max_amba_addr;
 147         pci_set_consistent_dma_mask(pdev, max_amba_addr);
 148         pci_set_dma_mask(pdev, max_amba_addr);
 149
 150         /* Configure AHB mapping */
 151         pci_write_config_dword(pdev, AHB_PEXLBASE(0), 0);
 152         pci_write_config_dword(pdev, AHB_PEXHBASE(0), 0);
 153         pci_write_config_dword(pdev, AHB_CRW(0), STA2X11_AMBA_SIZE |
 154                                AHB_CRW_WTYPE_MEM | AHB_CRW_ENABLE);
 155
 156         /* Disable all the other windows */
 157         for (i = 1; i < STA2X11_NR_FUNCS; i++)
 158                 pci_write_config_dword(pdev, AHB_CRW(i), 0);
 159
 160         dev_info(&pdev->dev,
 161                  "sta2x11: Map EP %i: AMBA address %#8x-%#8x\n",
 162                  sta2x11_pdev_to_ep(pdev), amba_base, max_amba_addr);
 163 }
 164 DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, sta2x11_map_ep);
 165
 166 #ifdef CONFIG_PM /* Some register values must be saved and restored */
 167
 168 static struct sta2x11_mapping *sta2x11_pdev_to_mapping(struct pci_dev *pdev)
 169 {
 170         struct sta2x11_instance *instance;
 171         int ep;
 172
 173         instance = sta2x11_pdev_to_instance(pdev);
 174         if (!instance)
 175                 return NULL;
 176         ep = sta2x11_pdev_to_ep(pdev);
 177         return instance->map + ep;
 178 }
 179
 180 static void suspend_mapping(struct pci_dev *pdev)
 181 {
 182         struct sta2x11_mapping *map = sta2x11_pdev_to_mapping(pdev);
 183         int i;
 184
 185         if (!map)
 186                 return;
 187
 188         if (map->is_suspended)
 189                 return;
 190         map->is_suspended = 1;
 191
 192         /* Save all window configs */
 193         for (i = 0; i < STA2X11_NR_FUNCS; i++) {
 194                 struct sta2x11_ahb_regs *regs = map->regs + i;
 195
 196                 pci_read_config_dword(pdev, AHB_BASE(i), &regs->base);
 197                 pci_read_config_dword(pdev, AHB_PEXLBASE(i), &regs->pexlbase);
 198                 pci_read_config_dword(pdev, AHB_PEXHBASE(i), &regs->pexhbase);
 199                 pci_read_config_dword(pdev, AHB_CRW(i), &regs->crw);
 200         }
 201 }
 202 DECLARE_PCI_FIXUP_SUSPEND(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, suspend_mapping);
 203
 204 static void resume_mapping(struct pci_dev *pdev)
 205 {
 206         struct sta2x11_mapping *map = sta2x11_pdev_to_mapping(pdev);
 207         int i;
 208
 209         if (!map)
 210                 return;
 211
 212
 213         if (!map->is_suspended)
 214                 goto out;
 215         map->is_suspended = 0;
 216
 217         /* Restore all window configs */
 218         for (i = 0; i < STA2X11_NR_FUNCS; i++) {
 219                 struct sta2x11_ahb_regs *regs = map->regs + i;
 220
 221                 pci_write_config_dword(pdev, AHB_BASE(i), regs->base);
 222                 pci_write_config_dword(pdev, AHB_PEXLBASE(i), regs->pexlbase);
 223                 pci_write_config_dword(pdev, AHB_PEXHBASE(i), regs->pexhbase);
 224                 pci_write_config_dword(pdev, AHB_CRW(i), regs->crw);
 225         }
 226 out:
 227         pci_set_master(pdev); /* Like at boot, enable master on all devices */
 228 }
 229 DECLARE_PCI_FIXUP_RESUME(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, resume_mapping);
 230
 231 #endif /* CONFIG_PM */