1 /* 2 * Resource table and its types data structure 3 * 4 * Copyright(c) 2011 Texas Instruments, Inc. 5 * Copyright(c) 2011 Google, Inc. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 12 * * Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * * Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in 16 * the documentation and/or other materials provided with the 17 * distribution. 18 * * Neither the name Texas Instruments nor the names of its 19 * contributors may be used to endorse or promote products derived 20 * from this software without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 23 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 24 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 25 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 26 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 27 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 28 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 29 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 30 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 31 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 32 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 33 */ 34 35 #ifndef RSC_TABLE_H 36 #define RSC_TABLE_H 37 38 /** 39 * struct resource_table - firmware resource table header 40 * @ver: version number 41 * @num: number of resource entries 42 * @reserved: reserved (must be zero) 43 * @offset: array of offsets pointing at the various resource entries 44 * 45 * A resource table is essentially a list of system resources required 46 * by the remote processor. It may also include configuration entries. 47 * If needed, the remote processor firmware should contain this table 48 * as a dedicated ".resource_table" ELF section. 49 * 50 * Some resources entries are mere announcements, where the host is informed 51 * of specific remoteproc configuration. Other entries require the host to 52 * do something (e.g. allocate a system resource). Sometimes a negotiation 53 * is expected, where the firmware requests a resource, and once allocated, 54 * the host should provide back its details (e.g. address of an allocated 55 * memory region). 56 * 57 * The header of the resource table, as expressed by this structure, 58 * contains a version number (should we need to change this format in the 59 * future), the number of available resource entries, and their offsets 60 * in the table. 61 * 62 * Immediately following this header are the resource entries themselves, 63 * each of which begins with a resource entry header (as described below). 64 */ 65 struct resource_table { 66 u32 ver; 67 u32 num; 68 u32 reserved[2]; 69 u32 offset[]; 70 } __packed; 71 72 /** 73 * struct fw_rsc_hdr - firmware resource entry header 74 * @type: resource type 75 * @data: resource data 76 * 77 * Every resource entry begins with a 'struct fw_rsc_hdr' header providing 78 * its @type. The content of the entry itself will immediately follow 79 * this header, and it should be parsed according to the resource type. 80 */ 81 struct fw_rsc_hdr { 82 u32 type; 83 u8 data[]; 84 } __packed; 85 86 /** 87 * enum fw_resource_type - types of resource entries 88 * 89 * @RSC_CARVEOUT: request for allocation of a physically contiguous 90 * memory region. 91 * @RSC_DEVMEM: request to iommu_map a memory-based peripheral. 92 * @RSC_TRACE: announces the availability of a trace buffer into which 93 * the remote processor will be writing logs. 94 * @RSC_VDEV: declare support for a virtio device, and serve as its 95 * virtio header. 96 * @RSC_LAST: just keep this one at the end of standard resources 97 * @RSC_VENDOR_START: start of the vendor specific resource types range 98 * @RSC_VENDOR_END: end of the vendor specific resource types range 99 * 100 * For more details regarding a specific resource type, please see its 101 * dedicated structure below. 102 * 103 * Please note that these values are used as indices to the rproc_handle_rsc 104 * lookup table, so please keep them sane. Moreover, @RSC_LAST is used to 105 * check the validity of an index before the lookup table is accessed, so 106 * please update it as needed. 107 */ 108 enum fw_resource_type { 109 RSC_CARVEOUT = 0, 110 RSC_DEVMEM = 1, 111 RSC_TRACE = 2, 112 RSC_VDEV = 3, 113 RSC_LAST = 4, 114 RSC_VENDOR_START = 128, 115 RSC_VENDOR_END = 512, 116 }; 117 118 #define FW_RSC_ADDR_ANY (-1) 119 120 /** 121 * struct fw_rsc_carveout - physically contiguous memory request 122 * @da: device address 123 * @pa: physical address 124 * @len: length (in bytes) 125 * @flags: iommu protection flags 126 * @reserved: reserved (must be zero) 127 * @name: human-readable name of the requested memory region 128 * 129 * This resource entry requests the host to allocate a physically contiguous 130 * memory region. 131 * 132 * These request entries should precede other firmware resource entries, 133 * as other entries might request placing other data objects inside 134 * these memory regions (e.g. data/code segments, trace resource entries, ...). 135 * 136 * Allocating memory this way helps utilizing the reserved physical memory 137 * (e.g. CMA) more efficiently, and also minimizes the number of TLB entries 138 * needed to map it (in case @rproc is using an IOMMU). Reducing the TLB 139 * pressure is important; it may have a substantial impact on performance. 140 * 141 * If the firmware is compiled with static addresses, then @da should specify 142 * the expected device address of this memory region. If @da is set to 143 * FW_RSC_ADDR_ANY, then the host will dynamically allocate it, and then 144 * overwrite @da with the dynamically allocated address. 145 * 146 * We will always use @da to negotiate the device addresses, even if it 147 * isn't using an iommu. In that case, though, it will obviously contain 148 * physical addresses. 149 * 150 * Some remote processors needs to know the allocated physical address 151 * even if they do use an iommu. This is needed, e.g., if they control 152 * hardware accelerators which access the physical memory directly (this 153 * is the case with OMAP4 for instance). In that case, the host will 154 * overwrite @pa with the dynamically allocated physical address. 155 * Generally we don't want to expose physical addresses if we don't have to 156 * (remote processors are generally _not_ trusted), so we might want to 157 * change this to happen _only_ when explicitly required by the hardware. 158 * 159 * @flags is used to provide IOMMU protection flags, and @name should 160 * (optionally) contain a human readable name of this carveout region 161 * (mainly for debugging purposes). 162 */ 163 struct fw_rsc_carveout { 164 u32 da; 165 u32 pa; 166 u32 len; 167 u32 flags; 168 u32 reserved; 169 u8 name[32]; 170 } __packed; 171 172 /** 173 * struct fw_rsc_devmem - iommu mapping request 174 * @da: device address 175 * @pa: physical address 176 * @len: length (in bytes) 177 * @flags: iommu protection flags 178 * @reserved: reserved (must be zero) 179 * @name: human-readable name of the requested region to be mapped 180 * 181 * This resource entry requests the host to iommu map a physically contiguous 182 * memory region. This is needed in case the remote processor requires 183 * access to certain memory-based peripherals; _never_ use it to access 184 * regular memory. 185 * 186 * This is obviously only needed if the remote processor is accessing memory 187 * via an iommu. 188 * 189 * @da should specify the required device address, @pa should specify 190 * the physical address we want to map, @len should specify the size of 191 * the mapping and @flags is the IOMMU protection flags. As always, @name may 192 * (optionally) contain a human readable name of this mapping (mainly for 193 * debugging purposes). 194 * 195 * Note: at this point we just "trust" those devmem entries to contain valid 196 * physical addresses, but this isn't safe and will be changed: eventually we 197 * want remoteproc implementations to provide us ranges of physical addresses 198 * the firmware is allowed to request, and not allow firmwares to request 199 * access to physical addresses that are outside those ranges. 200 */ 201 struct fw_rsc_devmem { 202 u32 da; 203 u32 pa; 204 u32 len; 205 u32 flags; 206 u32 reserved; 207 u8 name[32]; 208 } __packed; 209 210 /** 211 * struct fw_rsc_trace - trace buffer declaration 212 * @da: device address 213 * @len: length (in bytes) 214 * @reserved: reserved (must be zero) 215 * @name: human-readable name of the trace buffer 216 * 217 * This resource entry provides the host information about a trace buffer 218 * into which the remote processor will write log messages. 219 * 220 * @da specifies the device address of the buffer, @len specifies 221 * its size, and @name may contain a human readable name of the trace buffer. 222 * 223 * After booting the remote processor, the trace buffers are exposed to the 224 * user via debugfs entries (called trace0, trace1, etc..). 225 */ 226 struct fw_rsc_trace { 227 u32 da; 228 u32 len; 229 u32 reserved; 230 u8 name[32]; 231 } __packed; 232 233 /** 234 * struct fw_rsc_vdev_vring - vring descriptor entry 235 * @da: device address 236 * @align: the alignment between the consumer and producer parts of the vring 237 * @num: num of buffers supported by this vring (must be power of two) 238 * @notifyid: a unique rproc-wide notify index for this vring. This notify 239 * index is used when kicking a remote processor, to let it know that this 240 * vring is triggered. 241 * @pa: physical address 242 * 243 * This descriptor is not a resource entry by itself; it is part of the 244 * vdev resource type (see below). 245 * 246 * Note that @da should either contain the device address where 247 * the remote processor is expecting the vring, or indicate that 248 * dynamically allocation of the vring's device address is supported. 249 */ 250 struct fw_rsc_vdev_vring { 251 u32 da; 252 u32 align; 253 u32 num; 254 u32 notifyid; 255 u32 pa; 256 } __packed; 257 258 /** 259 * struct fw_rsc_vdev - virtio device header 260 * @id: virtio device id (as in virtio_ids.h) 261 * @notifyid: a unique rproc-wide notify index for this vdev. This notify 262 * index is used when kicking a remote processor, to let it know that the 263 * status/features of this vdev have changes. 264 * @dfeatures: specifies the virtio device features supported by the firmware 265 * @gfeatures: a place holder used by the host to write back the 266 * negotiated features that are supported by both sides. 267 * @config_len: the size of the virtio config space of this vdev. The config 268 * space lies in the resource table immediate after this vdev header. 269 * @status: a place holder where the host will indicate its virtio progress. 270 * @num_of_vrings: indicates how many vrings are described in this vdev header 271 * @reserved: reserved (must be zero) 272 * @vring: an array of @num_of_vrings entries of 'struct fw_rsc_vdev_vring'. 273 * 274 * This resource is a virtio device header: it provides information about 275 * the vdev, and is then used by the host and its peer remote processors 276 * to negotiate and share certain virtio properties. 277 * 278 * By providing this resource entry, the firmware essentially asks remoteproc 279 * to statically allocate a vdev upon registration of the rproc (dynamic vdev 280 * allocation is not yet supported). 281 * 282 * Note: 283 * 1. unlike virtualization systems, the term 'host' here means 284 * the Linux side which is running remoteproc to control the remote 285 * processors. We use the name 'gfeatures' to comply with virtio's terms, 286 * though there isn't really any virtualized guest OS here: it's the host 287 * which is responsible for negotiating the final features. 288 * Yeah, it's a bit confusing. 289 * 290 * 2. immediately following this structure is the virtio config space for 291 * this vdev (which is specific to the vdev; for more info, read the virtio 292 * spec). The size of the config space is specified by @config_len. 293 */ 294 struct fw_rsc_vdev { 295 u32 id; 296 u32 notifyid; 297 u32 dfeatures; 298 u32 gfeatures; 299 u32 config_len; 300 u8 status; 301 u8 num_of_vrings; 302 u8 reserved[2]; 303 struct fw_rsc_vdev_vring vring[]; 304 } __packed; 305 306 /** 307 * rsc_table_for_each_entry() - iterate over all entries in a resource table 308 * @table: pointer to the resource table 309 * @table_sz: total size of the table buffer in bytes 310 * @dev: device used for error logging 311 * @cb: callback invoked for each entry: 312 * @type - value from enum fw_resource_type 313 * @rsc - pointer to the entry payload (past struct fw_rsc_hdr) 314 * @offset - byte offset of the payload within the table; callers 315 * that write back into the table (e.g. to record a 316 * dynamically allocated address) use this to locate the 317 * entry for later update 318 * @avail - bytes available in the payload 319 * @data - caller-supplied private pointer 320 * Return 0 to continue iteration, non-zero to stop. 321 * @data: private pointer forwarded to @cb on every call 322 * 323 * Iterates over every resource entry in @table, performing the standard 324 * truncation check, and invokes @cb for each one. Iteration stops on the 325 * first non-zero return from @cb or on a malformed table. 326 * 327 * Returns 0 after a complete iteration, -EINVAL if the table is truncated, 328 * or the first non-zero value returned by @cb. 329 */ 330 static inline int rsc_table_for_each_entry(struct resource_table *table, 331 size_t table_sz, 332 struct device *dev, 333 int (*cb)(u32 type, void *rsc, 334 int offset, int avail, 335 void *data), 336 void *data) { 337 int i, ret; 338 339 for (i = 0; i < table->num; i++) { 340 int offset = table->offset[i]; 341 struct fw_rsc_hdr *hdr = (void *)table + offset; 342 int avail = table_sz - offset - sizeof(*hdr); 343 int rsc_offset = offset + sizeof(*hdr); 344 void *rsc = (void *)hdr + sizeof(*hdr); 345 346 if (avail < 0) { 347 dev_err(dev, "rsc table is truncated\n"); 348 return -EINVAL; 349 } 350 351 ret = cb(hdr->type, rsc, rsc_offset, avail, data); 352 if (ret) 353 return ret; 354 } 355 356 return 0; 357 } 358 359 #endif /* RSC_TABLE_H */ 360