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 u32 amba_base; 34 int is_suspended; 35 struct sta2x11_ahb_regs regs[STA2X11_NR_FUNCS]; 36 }; 37 38 struct sta2x11_instance { 39 struct list_head list; 40 int bus0; 41 struct sta2x11_mapping map[STA2X11_NR_EP]; 42 }; 43 44 static LIST_HEAD(sta2x11_instance_list); 45 46 /* At probe time, record new instances of this bridge (likely one only) */ 47 static void sta2x11_new_instance(struct pci_dev *pdev) 48 { 49 struct sta2x11_instance *instance; 50 51 instance = kzalloc(sizeof(*instance), GFP_ATOMIC); 52 if (!instance) 53 return; 54 /* This has a subordinate bridge, with 4 more-subordinate ones */ 55 instance->bus0 = pdev->subordinate->number + 1; 56 57 if (list_empty(&sta2x11_instance_list)) { 58 int size = STA2X11_SWIOTLB_SIZE; 59 /* First instance: register your own swiotlb area */ 60 dev_info(&pdev->dev, "Using SWIOTLB (size %i)\n", size); 61 if (swiotlb_late_init_with_default_size(size)) 62 dev_emerg(&pdev->dev, "init swiotlb failed\n"); 63 } 64 list_add(&instance->list, &sta2x11_instance_list); 65 } 66 DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_STMICRO, 0xcc17, sta2x11_new_instance); 67 68 /* 69 * Utility functions used in this file from below 70 */ 71 static struct sta2x11_instance *sta2x11_pdev_to_instance(struct pci_dev *pdev) 72 { 73 struct sta2x11_instance *instance; 74 int ep; 75 76 list_for_each_entry(instance, &sta2x11_instance_list, list) { 77 ep = pdev->bus->number - instance->bus0; 78 if (ep >= 0 && ep < STA2X11_NR_EP) 79 return instance; 80 } 81 return NULL; 82 } 83 84 static int sta2x11_pdev_to_ep(struct pci_dev *pdev) 85 { 86 struct sta2x11_instance *instance; 87 88 instance = sta2x11_pdev_to_instance(pdev); 89 if (!instance) 90 return -1; 91 92 return pdev->bus->number - instance->bus0; 93 } 94 95 static struct sta2x11_mapping *sta2x11_pdev_to_mapping(struct pci_dev *pdev) 96 { 97 struct sta2x11_instance *instance; 98 int ep; 99 100 instance = sta2x11_pdev_to_instance(pdev); 101 if (!instance) 102 return NULL; 103 ep = sta2x11_pdev_to_ep(pdev); 104 return instance->map + ep; 105 } 106 107 /* This is exported, as some devices need to access the MFD registers */ 108 struct sta2x11_instance *sta2x11_get_instance(struct pci_dev *pdev) 109 { 110 return sta2x11_pdev_to_instance(pdev); 111 } 112 EXPORT_SYMBOL(sta2x11_get_instance); 113 114 115 /** 116 * p2a - Translate physical address to STA2x11 AMBA address, 117 * used for DMA transfers to STA2x11 118 * @p: Physical address 119 * @pdev: PCI device (must be hosted within the connext) 120 */ 121 static dma_addr_t p2a(dma_addr_t p, struct pci_dev *pdev) 122 { 123 struct sta2x11_mapping *map; 124 dma_addr_t a; 125 126 map = sta2x11_pdev_to_mapping(pdev); 127 a = p + map->amba_base; 128 return a; 129 } 130 131 /** 132 * a2p - Translate STA2x11 AMBA address to physical address 133 * used for DMA transfers from STA2x11 134 * @a: STA2x11 AMBA address 135 * @pdev: PCI device (must be hosted within the connext) 136 */ 137 static dma_addr_t a2p(dma_addr_t a, struct pci_dev *pdev) 138 { 139 struct sta2x11_mapping *map; 140 dma_addr_t p; 141 142 map = sta2x11_pdev_to_mapping(pdev); 143 p = a - map->amba_base; 144 return p; 145 } 146 147 /* At setup time, we use our own ops if the device is a ConneXt one */ 148 static void sta2x11_setup_pdev(struct pci_dev *pdev) 149 { 150 struct sta2x11_instance *instance = sta2x11_pdev_to_instance(pdev); 151 152 if (!instance) /* either a sta2x11 bridge or another ST device */ 153 return; 154 pci_set_consistent_dma_mask(pdev, STA2X11_AMBA_SIZE - 1); 155 pci_set_dma_mask(pdev, STA2X11_AMBA_SIZE - 1); 156 pdev->dev.archdata.is_sta2x11 = true; 157 158 /* We must enable all devices as master, for audio DMA to work */ 159 pci_set_master(pdev); 160 } 161 DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, sta2x11_setup_pdev); 162 163 /* 164 * The following three functions are exported (used in swiotlb: FIXME) 165 */ 166 /** 167 * dma_capable - Check if device can manage DMA transfers (FIXME: kill it) 168 * @dev: device for a PCI device 169 * @addr: DMA address 170 * @size: DMA size 171 */ 172 bool dma_capable(struct device *dev, dma_addr_t addr, size_t size) 173 { 174 struct sta2x11_mapping *map; 175 176 if (!dev->archdata.is_sta2x11) { 177 if (!dev->dma_mask) 178 return false; 179 return addr + size - 1 <= *dev->dma_mask; 180 } 181 182 map = sta2x11_pdev_to_mapping(to_pci_dev(dev)); 183 184 if (!map || (addr < map->amba_base)) 185 return false; 186 if (addr + size >= map->amba_base + STA2X11_AMBA_SIZE) { 187 return false; 188 } 189 190 return true; 191 } 192 193 /** 194 * __phys_to_dma - Return the DMA AMBA address used for this STA2x11 device 195 * @dev: device for a PCI device 196 * @paddr: Physical address 197 */ 198 dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr) 199 { 200 if (!dev->archdata.is_sta2x11) 201 return paddr; 202 return p2a(paddr, to_pci_dev(dev)); 203 } 204 205 /** 206 * dma_to_phys - Return the physical address used for this STA2x11 DMA address 207 * @dev: device for a PCI device 208 * @daddr: STA2x11 AMBA DMA address 209 */ 210 phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t daddr) 211 { 212 if (!dev->archdata.is_sta2x11) 213 return daddr; 214 return a2p(daddr, to_pci_dev(dev)); 215 } 216 217 218 /* 219 * At boot we must set up the mappings for the pcie-to-amba bridge. 220 * It involves device access, and the same happens at suspend/resume time 221 */ 222 223 #define AHB_MAPB 0xCA4 224 #define AHB_CRW(i) (AHB_MAPB + 0 + (i) * 0x10) 225 #define AHB_CRW_SZMASK 0xfffffc00UL 226 #define AHB_CRW_ENABLE (1 << 0) 227 #define AHB_CRW_WTYPE_MEM (2 << 1) 228 #define AHB_CRW_ROE (1UL << 3) /* Relax Order Ena */ 229 #define AHB_CRW_NSE (1UL << 4) /* No Snoop Enable */ 230 #define AHB_BASE(i) (AHB_MAPB + 4 + (i) * 0x10) 231 #define AHB_PEXLBASE(i) (AHB_MAPB + 8 + (i) * 0x10) 232 #define AHB_PEXHBASE(i) (AHB_MAPB + 12 + (i) * 0x10) 233 234 /* At probe time, enable mapping for each endpoint, using the pdev */ 235 static void sta2x11_map_ep(struct pci_dev *pdev) 236 { 237 struct sta2x11_mapping *map = sta2x11_pdev_to_mapping(pdev); 238 int i; 239 240 if (!map) 241 return; 242 pci_read_config_dword(pdev, AHB_BASE(0), &map->amba_base); 243 244 /* Configure AHB mapping */ 245 pci_write_config_dword(pdev, AHB_PEXLBASE(0), 0); 246 pci_write_config_dword(pdev, AHB_PEXHBASE(0), 0); 247 pci_write_config_dword(pdev, AHB_CRW(0), STA2X11_AMBA_SIZE | 248 AHB_CRW_WTYPE_MEM | AHB_CRW_ENABLE); 249 250 /* Disable all the other windows */ 251 for (i = 1; i < STA2X11_NR_FUNCS; i++) 252 pci_write_config_dword(pdev, AHB_CRW(i), 0); 253 254 dev_info(&pdev->dev, 255 "sta2x11: Map EP %i: AMBA address %#8x-%#8x\n", 256 sta2x11_pdev_to_ep(pdev), map->amba_base, 257 map->amba_base + STA2X11_AMBA_SIZE - 1); 258 } 259 DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, sta2x11_map_ep); 260 261 #ifdef CONFIG_PM /* Some register values must be saved and restored */ 262 263 static void suspend_mapping(struct pci_dev *pdev) 264 { 265 struct sta2x11_mapping *map = sta2x11_pdev_to_mapping(pdev); 266 int i; 267 268 if (!map) 269 return; 270 271 if (map->is_suspended) 272 return; 273 map->is_suspended = 1; 274 275 /* Save all window configs */ 276 for (i = 0; i < STA2X11_NR_FUNCS; i++) { 277 struct sta2x11_ahb_regs *regs = map->regs + i; 278 279 pci_read_config_dword(pdev, AHB_BASE(i), ®s->base); 280 pci_read_config_dword(pdev, AHB_PEXLBASE(i), ®s->pexlbase); 281 pci_read_config_dword(pdev, AHB_PEXHBASE(i), ®s->pexhbase); 282 pci_read_config_dword(pdev, AHB_CRW(i), ®s->crw); 283 } 284 } 285 DECLARE_PCI_FIXUP_SUSPEND(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, suspend_mapping); 286 287 static void resume_mapping(struct pci_dev *pdev) 288 { 289 struct sta2x11_mapping *map = sta2x11_pdev_to_mapping(pdev); 290 int i; 291 292 if (!map) 293 return; 294 295 296 if (!map->is_suspended) 297 goto out; 298 map->is_suspended = 0; 299 300 /* Restore all window configs */ 301 for (i = 0; i < STA2X11_NR_FUNCS; i++) { 302 struct sta2x11_ahb_regs *regs = map->regs + i; 303 304 pci_write_config_dword(pdev, AHB_BASE(i), regs->base); 305 pci_write_config_dword(pdev, AHB_PEXLBASE(i), regs->pexlbase); 306 pci_write_config_dword(pdev, AHB_PEXHBASE(i), regs->pexhbase); 307 pci_write_config_dword(pdev, AHB_CRW(i), regs->crw); 308 } 309 out: 310 pci_set_master(pdev); /* Like at boot, enable master on all devices */ 311 } 312 DECLARE_PCI_FIXUP_RESUME(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, resume_mapping); 313 314 #endif /* CONFIG_PM */ 315