1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * arch/x86/pci/sta2x11-fixup.c 4 * glue code for lib/swiotlb.c and DMA translation between STA2x11 5 * AMBA memory mapping and the X86 memory mapping 6 * 7 * ST Microelectronics ConneXt (STA2X11/STA2X10) 8 * 9 * Copyright (c) 2010-2011 Wind River Systems, Inc. 10 */ 11 12 #include <linux/pci.h> 13 #include <linux/pci_ids.h> 14 #include <linux/export.h> 15 #include <linux/list.h> 16 #include <linux/dma-direct.h> 17 #include <asm/iommu.h> 18 19 #define STA2X11_SWIOTLB_SIZE (4*1024*1024) 20 extern int swiotlb_late_init_with_default_size(size_t default_size); 21 22 /* 23 * We build a list of bus numbers that are under the ConneXt. The 24 * main bridge hosts 4 busses, which are the 4 endpoints, in order. 25 */ 26 #define STA2X11_NR_EP 4 /* 0..3 included */ 27 #define STA2X11_NR_FUNCS 8 /* 0..7 included */ 28 #define STA2X11_AMBA_SIZE (512 << 20) 29 30 struct sta2x11_ahb_regs { /* saved during suspend */ 31 u32 base, pexlbase, pexhbase, crw; 32 }; 33 34 struct sta2x11_mapping { 35 u32 amba_base; 36 int is_suspended; 37 struct sta2x11_ahb_regs regs[STA2X11_NR_FUNCS]; 38 }; 39 40 struct sta2x11_instance { 41 struct list_head list; 42 int bus0; 43 struct sta2x11_mapping map[STA2X11_NR_EP]; 44 }; 45 46 static LIST_HEAD(sta2x11_instance_list); 47 48 /* At probe time, record new instances of this bridge (likely one only) */ 49 static void sta2x11_new_instance(struct pci_dev *pdev) 50 { 51 struct sta2x11_instance *instance; 52 53 instance = kzalloc(sizeof(*instance), GFP_ATOMIC); 54 if (!instance) 55 return; 56 /* This has a subordinate bridge, with 4 more-subordinate ones */ 57 instance->bus0 = pdev->subordinate->number + 1; 58 59 if (list_empty(&sta2x11_instance_list)) { 60 int size = STA2X11_SWIOTLB_SIZE; 61 /* First instance: register your own swiotlb area */ 62 dev_info(&pdev->dev, "Using SWIOTLB (size %i)\n", size); 63 if (swiotlb_late_init_with_default_size(size)) 64 dev_emerg(&pdev->dev, "init swiotlb failed\n"); 65 } 66 list_add(&instance->list, &sta2x11_instance_list); 67 } 68 DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_STMICRO, 0xcc17, sta2x11_new_instance); 69 70 /* 71 * Utility functions used in this file from below 72 */ 73 static struct sta2x11_instance *sta2x11_pdev_to_instance(struct pci_dev *pdev) 74 { 75 struct sta2x11_instance *instance; 76 int ep; 77 78 list_for_each_entry(instance, &sta2x11_instance_list, list) { 79 ep = pdev->bus->number - instance->bus0; 80 if (ep >= 0 && ep < STA2X11_NR_EP) 81 return instance; 82 } 83 return NULL; 84 } 85 86 static int sta2x11_pdev_to_ep(struct pci_dev *pdev) 87 { 88 struct sta2x11_instance *instance; 89 90 instance = sta2x11_pdev_to_instance(pdev); 91 if (!instance) 92 return -1; 93 94 return pdev->bus->number - instance->bus0; 95 } 96 97 static struct sta2x11_mapping *sta2x11_pdev_to_mapping(struct pci_dev *pdev) 98 { 99 struct sta2x11_instance *instance; 100 int ep; 101 102 instance = sta2x11_pdev_to_instance(pdev); 103 if (!instance) 104 return NULL; 105 ep = sta2x11_pdev_to_ep(pdev); 106 return instance->map + ep; 107 } 108 109 /* This is exported, as some devices need to access the MFD registers */ 110 struct sta2x11_instance *sta2x11_get_instance(struct pci_dev *pdev) 111 { 112 return sta2x11_pdev_to_instance(pdev); 113 } 114 EXPORT_SYMBOL(sta2x11_get_instance); 115 116 117 /** 118 * p2a - Translate physical address to STA2x11 AMBA address, 119 * used for DMA transfers to STA2x11 120 * @p: Physical address 121 * @pdev: PCI device (must be hosted within the connext) 122 */ 123 static dma_addr_t p2a(dma_addr_t p, struct pci_dev *pdev) 124 { 125 struct sta2x11_mapping *map; 126 dma_addr_t a; 127 128 map = sta2x11_pdev_to_mapping(pdev); 129 a = p + map->amba_base; 130 return a; 131 } 132 133 /** 134 * a2p - Translate STA2x11 AMBA address to physical address 135 * used for DMA transfers from STA2x11 136 * @a: STA2x11 AMBA address 137 * @pdev: PCI device (must be hosted within the connext) 138 */ 139 static dma_addr_t a2p(dma_addr_t a, struct pci_dev *pdev) 140 { 141 struct sta2x11_mapping *map; 142 dma_addr_t p; 143 144 map = sta2x11_pdev_to_mapping(pdev); 145 p = a - map->amba_base; 146 return p; 147 } 148 149 /* At setup time, we use our own ops if the device is a ConneXt one */ 150 static void sta2x11_setup_pdev(struct pci_dev *pdev) 151 { 152 struct sta2x11_instance *instance = sta2x11_pdev_to_instance(pdev); 153 154 if (!instance) /* either a sta2x11 bridge or another ST device */ 155 return; 156 pci_set_consistent_dma_mask(pdev, STA2X11_AMBA_SIZE - 1); 157 pci_set_dma_mask(pdev, STA2X11_AMBA_SIZE - 1); 158 pdev->dev.archdata.is_sta2x11 = true; 159 160 /* We must enable all devices as master, for audio DMA to work */ 161 pci_set_master(pdev); 162 } 163 DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, sta2x11_setup_pdev); 164 165 /* 166 * The following three functions are exported (used in swiotlb: FIXME) 167 */ 168 /** 169 * dma_capable - Check if device can manage DMA transfers (FIXME: kill it) 170 * @dev: device for a PCI device 171 * @addr: DMA address 172 * @size: DMA size 173 */ 174 bool dma_capable(struct device *dev, dma_addr_t addr, size_t size) 175 { 176 struct sta2x11_mapping *map; 177 178 if (!dev->archdata.is_sta2x11) { 179 if (!dev->dma_mask) 180 return false; 181 return addr + size - 1 <= *dev->dma_mask; 182 } 183 184 map = sta2x11_pdev_to_mapping(to_pci_dev(dev)); 185 186 if (!map || (addr < map->amba_base)) 187 return false; 188 if (addr + size >= map->amba_base + STA2X11_AMBA_SIZE) { 189 return false; 190 } 191 192 return true; 193 } 194 195 /** 196 * __phys_to_dma - Return the DMA AMBA address used for this STA2x11 device 197 * @dev: device for a PCI device 198 * @paddr: Physical address 199 */ 200 dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr) 201 { 202 if (!dev->archdata.is_sta2x11) 203 return paddr; 204 return p2a(paddr, to_pci_dev(dev)); 205 } 206 207 /** 208 * dma_to_phys - Return the physical address used for this STA2x11 DMA address 209 * @dev: device for a PCI device 210 * @daddr: STA2x11 AMBA DMA address 211 */ 212 phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t daddr) 213 { 214 if (!dev->archdata.is_sta2x11) 215 return daddr; 216 return a2p(daddr, to_pci_dev(dev)); 217 } 218 219 220 /* 221 * At boot we must set up the mappings for the pcie-to-amba bridge. 222 * It involves device access, and the same happens at suspend/resume time 223 */ 224 225 #define AHB_MAPB 0xCA4 226 #define AHB_CRW(i) (AHB_MAPB + 0 + (i) * 0x10) 227 #define AHB_CRW_SZMASK 0xfffffc00UL 228 #define AHB_CRW_ENABLE (1 << 0) 229 #define AHB_CRW_WTYPE_MEM (2 << 1) 230 #define AHB_CRW_ROE (1UL << 3) /* Relax Order Ena */ 231 #define AHB_CRW_NSE (1UL << 4) /* No Snoop Enable */ 232 #define AHB_BASE(i) (AHB_MAPB + 4 + (i) * 0x10) 233 #define AHB_PEXLBASE(i) (AHB_MAPB + 8 + (i) * 0x10) 234 #define AHB_PEXHBASE(i) (AHB_MAPB + 12 + (i) * 0x10) 235 236 /* At probe time, enable mapping for each endpoint, using the pdev */ 237 static void sta2x11_map_ep(struct pci_dev *pdev) 238 { 239 struct sta2x11_mapping *map = sta2x11_pdev_to_mapping(pdev); 240 int i; 241 242 if (!map) 243 return; 244 pci_read_config_dword(pdev, AHB_BASE(0), &map->amba_base); 245 246 /* Configure AHB mapping */ 247 pci_write_config_dword(pdev, AHB_PEXLBASE(0), 0); 248 pci_write_config_dword(pdev, AHB_PEXHBASE(0), 0); 249 pci_write_config_dword(pdev, AHB_CRW(0), STA2X11_AMBA_SIZE | 250 AHB_CRW_WTYPE_MEM | AHB_CRW_ENABLE); 251 252 /* Disable all the other windows */ 253 for (i = 1; i < STA2X11_NR_FUNCS; i++) 254 pci_write_config_dword(pdev, AHB_CRW(i), 0); 255 256 dev_info(&pdev->dev, 257 "sta2x11: Map EP %i: AMBA address %#8x-%#8x\n", 258 sta2x11_pdev_to_ep(pdev), map->amba_base, 259 map->amba_base + STA2X11_AMBA_SIZE - 1); 260 } 261 DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, sta2x11_map_ep); 262 263 #ifdef CONFIG_PM /* Some register values must be saved and restored */ 264 265 static void suspend_mapping(struct pci_dev *pdev) 266 { 267 struct sta2x11_mapping *map = sta2x11_pdev_to_mapping(pdev); 268 int i; 269 270 if (!map) 271 return; 272 273 if (map->is_suspended) 274 return; 275 map->is_suspended = 1; 276 277 /* Save all window configs */ 278 for (i = 0; i < STA2X11_NR_FUNCS; i++) { 279 struct sta2x11_ahb_regs *regs = map->regs + i; 280 281 pci_read_config_dword(pdev, AHB_BASE(i), ®s->base); 282 pci_read_config_dword(pdev, AHB_PEXLBASE(i), ®s->pexlbase); 283 pci_read_config_dword(pdev, AHB_PEXHBASE(i), ®s->pexhbase); 284 pci_read_config_dword(pdev, AHB_CRW(i), ®s->crw); 285 } 286 } 287 DECLARE_PCI_FIXUP_SUSPEND(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, suspend_mapping); 288 289 static void resume_mapping(struct pci_dev *pdev) 290 { 291 struct sta2x11_mapping *map = sta2x11_pdev_to_mapping(pdev); 292 int i; 293 294 if (!map) 295 return; 296 297 298 if (!map->is_suspended) 299 goto out; 300 map->is_suspended = 0; 301 302 /* Restore all window configs */ 303 for (i = 0; i < STA2X11_NR_FUNCS; i++) { 304 struct sta2x11_ahb_regs *regs = map->regs + i; 305 306 pci_write_config_dword(pdev, AHB_BASE(i), regs->base); 307 pci_write_config_dword(pdev, AHB_PEXLBASE(i), regs->pexlbase); 308 pci_write_config_dword(pdev, AHB_PEXHBASE(i), regs->pexhbase); 309 pci_write_config_dword(pdev, AHB_CRW(i), regs->crw); 310 } 311 out: 312 pci_set_master(pdev); /* Like at boot, enable master on all devices */ 313 } 314 DECLARE_PCI_FIXUP_RESUME(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, resume_mapping); 315 316 #endif /* CONFIG_PM */ 317