1 // SPDX-License-Identifier: GPL-2.0-only 2 /* Copyright(c) 2020 Intel Corporation. */ 3 #include <linux/io-64-nonatomic-lo-hi.h> 4 #include <linux/device.h> 5 #include <linux/slab.h> 6 #include <linux/pci.h> 7 #include <cxlmem.h> 8 9 /** 10 * DOC: cxl registers 11 * 12 * CXL device capabilities are enumerated by PCI DVSEC (Designated 13 * Vendor-specific) and / or descriptors provided by platform firmware. 14 * They can be defined as a set like the device and component registers 15 * mandated by CXL Section 8.1.12.2 Memory Device PCIe Capabilities and 16 * Extended Capabilities, or they can be individual capabilities 17 * appended to bridged and endpoint devices. 18 * 19 * Provide common infrastructure for enumerating and mapping these 20 * discrete capabilities. 21 */ 22 23 /** 24 * cxl_probe_component_regs() - Detect CXL Component register blocks 25 * @dev: Host device of the @base mapping 26 * @base: Mapping containing the HDM Decoder Capability Header 27 * @map: Map object describing the register block information found 28 * 29 * See CXL 2.0 8.2.4 Component Register Layout and Definition 30 * See CXL 2.0 8.2.5.5 CXL Device Register Interface 31 * 32 * Probe for component register information and return it in map object. 33 */ 34 void cxl_probe_component_regs(struct device *dev, void __iomem *base, 35 struct cxl_component_reg_map *map) 36 { 37 int cap, cap_count; 38 u64 cap_array; 39 40 *map = (struct cxl_component_reg_map) { 0 }; 41 42 /* 43 * CXL.cache and CXL.mem registers are at offset 0x1000 as defined in 44 * CXL 2.0 8.2.4 Table 141. 45 */ 46 base += CXL_CM_OFFSET; 47 48 cap_array = readq(base + CXL_CM_CAP_HDR_OFFSET); 49 50 if (FIELD_GET(CXL_CM_CAP_HDR_ID_MASK, cap_array) != CM_CAP_HDR_CAP_ID) { 51 dev_err(dev, 52 "Couldn't locate the CXL.cache and CXL.mem capability array header./n"); 53 return; 54 } 55 56 /* It's assumed that future versions will be backward compatible */ 57 cap_count = FIELD_GET(CXL_CM_CAP_HDR_ARRAY_SIZE_MASK, cap_array); 58 59 for (cap = 1; cap <= cap_count; cap++) { 60 void __iomem *register_block; 61 u32 hdr; 62 int decoder_cnt; 63 u16 cap_id, offset; 64 u32 length; 65 66 hdr = readl(base + cap * 0x4); 67 68 cap_id = FIELD_GET(CXL_CM_CAP_HDR_ID_MASK, hdr); 69 offset = FIELD_GET(CXL_CM_CAP_PTR_MASK, hdr); 70 register_block = base + offset; 71 72 switch (cap_id) { 73 case CXL_CM_CAP_CAP_ID_HDM: 74 dev_dbg(dev, "found HDM decoder capability (0x%x)\n", 75 offset); 76 77 hdr = readl(register_block); 78 79 decoder_cnt = cxl_hdm_decoder_count(hdr); 80 length = 0x20 * decoder_cnt + 0x10; 81 82 map->hdm_decoder.valid = true; 83 map->hdm_decoder.offset = CXL_CM_OFFSET + offset; 84 map->hdm_decoder.size = length; 85 break; 86 default: 87 dev_dbg(dev, "Unknown CM cap ID: %d (0x%x)\n", cap_id, 88 offset); 89 break; 90 } 91 } 92 } 93 EXPORT_SYMBOL_GPL(cxl_probe_component_regs); 94 95 /** 96 * cxl_probe_device_regs() - Detect CXL Device register blocks 97 * @dev: Host device of the @base mapping 98 * @base: Mapping of CXL 2.0 8.2.8 CXL Device Register Interface 99 * @map: Map object describing the register block information found 100 * 101 * Probe for device register information and return it in map object. 102 */ 103 void cxl_probe_device_regs(struct device *dev, void __iomem *base, 104 struct cxl_device_reg_map *map) 105 { 106 int cap, cap_count; 107 u64 cap_array; 108 109 *map = (struct cxl_device_reg_map){ 0 }; 110 111 cap_array = readq(base + CXLDEV_CAP_ARRAY_OFFSET); 112 if (FIELD_GET(CXLDEV_CAP_ARRAY_ID_MASK, cap_array) != 113 CXLDEV_CAP_ARRAY_CAP_ID) 114 return; 115 116 cap_count = FIELD_GET(CXLDEV_CAP_ARRAY_COUNT_MASK, cap_array); 117 118 for (cap = 1; cap <= cap_count; cap++) { 119 u32 offset, length; 120 u16 cap_id; 121 122 cap_id = FIELD_GET(CXLDEV_CAP_HDR_CAP_ID_MASK, 123 readl(base + cap * 0x10)); 124 offset = readl(base + cap * 0x10 + 0x4); 125 length = readl(base + cap * 0x10 + 0x8); 126 127 switch (cap_id) { 128 case CXLDEV_CAP_CAP_ID_DEVICE_STATUS: 129 dev_dbg(dev, "found Status capability (0x%x)\n", offset); 130 131 map->status.valid = true; 132 map->status.offset = offset; 133 map->status.size = length; 134 break; 135 case CXLDEV_CAP_CAP_ID_PRIMARY_MAILBOX: 136 dev_dbg(dev, "found Mailbox capability (0x%x)\n", offset); 137 map->mbox.valid = true; 138 map->mbox.offset = offset; 139 map->mbox.size = length; 140 break; 141 case CXLDEV_CAP_CAP_ID_SECONDARY_MAILBOX: 142 dev_dbg(dev, "found Secondary Mailbox capability (0x%x)\n", offset); 143 break; 144 case CXLDEV_CAP_CAP_ID_MEMDEV: 145 dev_dbg(dev, "found Memory Device capability (0x%x)\n", offset); 146 map->memdev.valid = true; 147 map->memdev.offset = offset; 148 map->memdev.size = length; 149 break; 150 default: 151 if (cap_id >= 0x8000) 152 dev_dbg(dev, "Vendor cap ID: %#x offset: %#x\n", cap_id, offset); 153 else 154 dev_dbg(dev, "Unknown cap ID: %#x offset: %#x\n", cap_id, offset); 155 break; 156 } 157 } 158 } 159 EXPORT_SYMBOL_GPL(cxl_probe_device_regs); 160 161 static void __iomem *devm_cxl_iomap_block(struct device *dev, 162 resource_size_t addr, 163 resource_size_t length) 164 { 165 void __iomem *ret_val; 166 struct resource *res; 167 168 res = devm_request_mem_region(dev, addr, length, dev_name(dev)); 169 if (!res) { 170 resource_size_t end = addr + length - 1; 171 172 dev_err(dev, "Failed to request region %pa-%pa\n", &addr, &end); 173 return NULL; 174 } 175 176 ret_val = devm_ioremap(dev, addr, length); 177 if (!ret_val) 178 dev_err(dev, "Failed to map region %pr\n", res); 179 180 return ret_val; 181 } 182 183 int cxl_map_component_regs(struct pci_dev *pdev, 184 struct cxl_component_regs *regs, 185 struct cxl_register_map *map) 186 { 187 struct device *dev = &pdev->dev; 188 resource_size_t phys_addr; 189 resource_size_t length; 190 191 phys_addr = pci_resource_start(pdev, map->barno); 192 phys_addr += map->block_offset; 193 194 phys_addr += map->component_map.hdm_decoder.offset; 195 length = map->component_map.hdm_decoder.size; 196 regs->hdm_decoder = devm_cxl_iomap_block(dev, phys_addr, length); 197 if (!regs->hdm_decoder) 198 return -ENOMEM; 199 200 return 0; 201 } 202 EXPORT_SYMBOL_GPL(cxl_map_component_regs); 203 204 int cxl_map_device_regs(struct pci_dev *pdev, 205 struct cxl_device_regs *regs, 206 struct cxl_register_map *map) 207 { 208 struct device *dev = &pdev->dev; 209 resource_size_t phys_addr; 210 211 phys_addr = pci_resource_start(pdev, map->barno); 212 phys_addr += map->block_offset; 213 214 if (map->device_map.status.valid) { 215 resource_size_t addr; 216 resource_size_t length; 217 218 addr = phys_addr + map->device_map.status.offset; 219 length = map->device_map.status.size; 220 regs->status = devm_cxl_iomap_block(dev, addr, length); 221 if (!regs->status) 222 return -ENOMEM; 223 } 224 225 if (map->device_map.mbox.valid) { 226 resource_size_t addr; 227 resource_size_t length; 228 229 addr = phys_addr + map->device_map.mbox.offset; 230 length = map->device_map.mbox.size; 231 regs->mbox = devm_cxl_iomap_block(dev, addr, length); 232 if (!regs->mbox) 233 return -ENOMEM; 234 } 235 236 if (map->device_map.memdev.valid) { 237 resource_size_t addr; 238 resource_size_t length; 239 240 addr = phys_addr + map->device_map.memdev.offset; 241 length = map->device_map.memdev.size; 242 regs->memdev = devm_cxl_iomap_block(dev, addr, length); 243 if (!regs->memdev) 244 return -ENOMEM; 245 } 246 247 return 0; 248 } 249 EXPORT_SYMBOL_GPL(cxl_map_device_regs); 250