/* * Remote Processor Framework * * Copyright (C) 2011 Texas Instruments, Inc. * Copyright (C) 2011 Google, Inc. * * Ohad Ben-Cohen * Brian Swetland * Mark Grosen * Fernando Guzman Lugo * Suman Anna * Robert Tivy * Armando Uribe De Leon * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * version 2 as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #define pr_fmt(fmt) "%s: " fmt, __func__ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "remoteproc_internal.h" static void klist_rproc_get(struct klist_node *n); static void klist_rproc_put(struct klist_node *n); /* * klist of the available remote processors. * * We need this in order to support name-based lookups (needed by the * rproc_get_by_name()). * * That said, we don't use rproc_get_by_name() at this point. * The use cases that do require its existence should be * scrutinized, and hopefully migrated to rproc_boot() using device-based * binding. * * If/when this materializes, we could drop the klist (and the by_name * API). */ static DEFINE_KLIST(rprocs, klist_rproc_get, klist_rproc_put); typedef int (*rproc_handle_resources_t)(struct rproc *rproc, struct resource_table *table, int len); typedef int (*rproc_handle_resource_t)(struct rproc *rproc, void *, int avail); /* * This is the IOMMU fault handler we register with the IOMMU API * (when relevant; not all remote processors access memory through * an IOMMU). * * IOMMU core will invoke this handler whenever the remote processor * will try to access an unmapped device address. * * Currently this is mostly a stub, but it will be later used to trigger * the recovery of the remote processor. */ static int rproc_iommu_fault(struct iommu_domain *domain, struct device *dev, unsigned long iova, int flags, void *token) { dev_err(dev, "iommu fault: da 0x%lx flags 0x%x\n", iova, flags); /* * Let the iommu core know we're not really handling this fault; * we just plan to use this as a recovery trigger. */ return -ENOSYS; } static int rproc_enable_iommu(struct rproc *rproc) { struct iommu_domain *domain; struct device *dev = rproc->dev; int ret; /* * We currently use iommu_present() to decide if an IOMMU * setup is needed. * * This works for simple cases, but will easily fail with * platforms that do have an IOMMU, but not for this specific * rproc. * * This will be easily solved by introducing hw capabilities * that will be set by the remoteproc driver. */ if (!iommu_present(dev->bus)) { dev_dbg(dev, "iommu not found\n"); return 0; } domain = iommu_domain_alloc(dev->bus); if (!domain) { dev_err(dev, "can't alloc iommu domain\n"); return -ENOMEM; } iommu_set_fault_handler(domain, rproc_iommu_fault, rproc); ret = iommu_attach_device(domain, dev); if (ret) { dev_err(dev, "can't attach iommu device: %d\n", ret); goto free_domain; } rproc->domain = domain; return 0; free_domain: iommu_domain_free(domain); return ret; } static void rproc_disable_iommu(struct rproc *rproc) { struct iommu_domain *domain = rproc->domain; struct device *dev = rproc->dev; if (!domain) return; iommu_detach_device(domain, dev); iommu_domain_free(domain); return; } /* * Some remote processors will ask us to allocate them physically contiguous * memory regions (which we call "carveouts"), and map them to specific * device addresses (which are hardcoded in the firmware). * * They may then ask us to copy objects into specific device addresses (e.g. * code/data sections) or expose us certain symbols in other device address * (e.g. their trace buffer). * * This function is an internal helper with which we can go over the allocated * carveouts and translate specific device address to kernel virtual addresses * so we can access the referenced memory. * * Note: phys_to_virt(iommu_iova_to_phys(rproc->domain, da)) will work too, * but only on kernel direct mapped RAM memory. Instead, we're just using * here the output of the DMA API, which should be more correct. */ static void *rproc_da_to_va(struct rproc *rproc, u64 da, int len) { struct rproc_mem_entry *carveout; void *ptr = NULL; list_for_each_entry(carveout, &rproc->carveouts, node) { int offset = da - carveout->da; /* try next carveout if da is too small */ if (offset < 0) continue; /* try next carveout if da is too large */ if (offset + len > carveout->len) continue; ptr = carveout->va + offset; break; } return ptr; } /** * rproc_load_segments() - load firmware segments to memory * @rproc: remote processor which will be booted using these fw segments * @elf_data: the content of the ELF firmware image * @len: firmware size (in bytes) * * This function loads the firmware segments to memory, where the remote * processor expects them. * * Some remote processors will expect their code and data to be placed * in specific device addresses, and can't have them dynamically assigned. * * We currently support only those kind of remote processors, and expect * the program header's paddr member to contain those addresses. We then go * through the physically contiguous "carveout" memory regions which we * allocated (and mapped) earlier on behalf of the remote processor, * and "translate" device address to kernel addresses, so we can copy the * segments where they are expected. * * Currently we only support remote processors that required carveout * allocations and got them mapped onto their iommus. Some processors * might be different: they might not have iommus, and would prefer to * directly allocate memory for every segment/resource. This is not yet * supported, though. */ static int rproc_load_segments(struct rproc *rproc, const u8 *elf_data, size_t len) { struct device *dev = rproc->dev; struct elf32_hdr *ehdr; struct elf32_phdr *phdr; int i, ret = 0; ehdr = (struct elf32_hdr *)elf_data; phdr = (struct elf32_phdr *)(elf_data + ehdr->e_phoff); /* go through the available ELF segments */ for (i = 0; i < ehdr->e_phnum; i++, phdr++) { u32 da = phdr->p_paddr; u32 memsz = phdr->p_memsz; u32 filesz = phdr->p_filesz; u32 offset = phdr->p_offset; void *ptr; if (phdr->p_type != PT_LOAD) continue; dev_dbg(dev, "phdr: type %d da 0x%x memsz 0x%x filesz 0x%x\n", phdr->p_type, da, memsz, filesz); if (filesz > memsz) { dev_err(dev, "bad phdr filesz 0x%x memsz 0x%x\n", filesz, memsz); ret = -EINVAL; break; } if (offset + filesz > len) { dev_err(dev, "truncated fw: need 0x%x avail 0x%x\n", offset + filesz, len); ret = -EINVAL; break; } /* grab the kernel address for this device address */ ptr = rproc_da_to_va(rproc, da, memsz); if (!ptr) { dev_err(dev, "bad phdr da 0x%x mem 0x%x\n", da, memsz); ret = -EINVAL; break; } /* put the segment where the remote processor expects it */ if (phdr->p_filesz) memcpy(ptr, elf_data + phdr->p_offset, filesz); /* * Zero out remaining memory for this segment. * * This isn't strictly required since dma_alloc_coherent already * did this for us. albeit harmless, we may consider removing * this. */ if (memsz > filesz) memset(ptr + filesz, 0, memsz - filesz); } return ret; } static int __rproc_handle_vring(struct rproc_vdev *rvdev, struct fw_rsc_vdev *rsc, int i) { struct rproc *rproc = rvdev->rproc; struct device *dev = rproc->dev; struct fw_rsc_vdev_vring *vring = &rsc->vring[i]; dma_addr_t dma; void *va; int ret, size, notifyid; dev_dbg(dev, "vdev rsc: vring%d: da %x, qsz %d, align %d\n", i, vring->da, vring->num, vring->align); /* make sure reserved bytes are zeroes */ if (vring->reserved) { dev_err(dev, "vring rsc has non zero reserved bytes\n"); return -EINVAL; } /* verify queue size and vring alignment are sane */ if (!vring->num || !vring->align) { dev_err(dev, "invalid qsz (%d) or alignment (%d)\n", vring->num, vring->align); return -EINVAL; } /* actual size of vring (in bytes) */ size = PAGE_ALIGN(vring_size(vring->num, vring->align)); if (!idr_pre_get(&rproc->notifyids, GFP_KERNEL)) { dev_err(dev, "idr_pre_get failed\n"); return -ENOMEM; } /* * Allocate non-cacheable memory for the vring. In the future * this call will also configure the IOMMU for us */ va = dma_alloc_coherent(dev, size, &dma, GFP_KERNEL); if (!va) { dev_err(dev, "dma_alloc_coherent failed\n"); return -EINVAL; } /* assign an rproc-wide unique index for this vring */ /* TODO: assign a notifyid for rvdev updates as well */ ret = idr_get_new(&rproc->notifyids, &rvdev->vring[i], ¬ifyid); if (ret) { dev_err(dev, "idr_get_new failed: %d\n", ret); dma_free_coherent(dev, size, va, dma); return ret; } /* let the rproc know the da and notifyid of this vring */ /* TODO: expose this to remote processor */ vring->da = dma; vring->notifyid = notifyid; dev_dbg(dev, "vring%d: va %p dma %x size %x idr %d\n", i, va, dma, size, notifyid); rvdev->vring[i].len = vring->num; rvdev->vring[i].align = vring->align; rvdev->vring[i].va = va; rvdev->vring[i].dma = dma; rvdev->vring[i].notifyid = notifyid; rvdev->vring[i].rvdev = rvdev; return 0; } static void __rproc_free_vrings(struct rproc_vdev *rvdev, int i) { struct rproc *rproc = rvdev->rproc; for (i--; i >= 0; i--) { struct rproc_vring *rvring = &rvdev->vring[i]; int size = PAGE_ALIGN(vring_size(rvring->len, rvring->align)); dma_free_coherent(rproc->dev, size, rvring->va, rvring->dma); idr_remove(&rproc->notifyids, rvring->notifyid); } } /** * rproc_handle_vdev() - handle a vdev fw resource * @rproc: the remote processor * @rsc: the vring resource descriptor * @avail: size of available data (for sanity checking the image) * * This resource entry requests the host to statically register a virtio * device (vdev), and setup everything needed to support it. It contains * everything needed to make it possible: the virtio device id, virtio * device features, vrings information, virtio config space, etc... * * Before registering the vdev, the vrings are allocated from non-cacheable * physically contiguous memory. Currently we only support two vrings per * remote processor (temporary limitation). We might also want to consider * doing the vring allocation only later when ->find_vqs() is invoked, and * then release them upon ->del_vqs(). * * Note: @da is currently not really handled correctly: we dynamically * allocate it using the DMA API, ignoring requested hard coded addresses, * and we don't take care of any required IOMMU programming. This is all * going to be taken care of when the generic iommu-based DMA API will be * merged. Meanwhile, statically-addressed iommu-based firmware images should * use RSC_DEVMEM resource entries to map their required @da to the physical * address of their base CMA region (ouch, hacky!). * * Returns 0 on success, or an appropriate error code otherwise */ static int rproc_handle_vdev(struct rproc *rproc, struct fw_rsc_vdev *rsc, int avail) { struct device *dev = rproc->dev; struct rproc_vdev *rvdev; int i, ret; /* make sure resource isn't truncated */ if (sizeof(*rsc) + rsc->num_of_vrings * sizeof(struct fw_rsc_vdev_vring) + rsc->config_len > avail) { dev_err(rproc->dev, "vdev rsc is truncated\n"); return -EINVAL; } /* make sure reserved bytes are zeroes */ if (rsc->reserved[0] || rsc->reserved[1]) { dev_err(dev, "vdev rsc has non zero reserved bytes\n"); return -EINVAL; } dev_dbg(dev, "vdev rsc: id %d, dfeatures %x, cfg len %d, %d vrings\n", rsc->id, rsc->dfeatures, rsc->config_len, rsc->num_of_vrings); /* we currently support only two vrings per rvdev */ if (rsc->num_of_vrings > ARRAY_SIZE(rvdev->vring)) { dev_err(dev, "too many vrings: %d\n", rsc->num_of_vrings); return -EINVAL; } rvdev = kzalloc(sizeof(struct rproc_vdev), GFP_KERNEL); if (!rvdev) return -ENOMEM; rvdev->rproc = rproc; /* allocate the vrings */ for (i = 0; i < rsc->num_of_vrings; i++) { ret = __rproc_handle_vring(rvdev, rsc, i); if (ret) goto free_vrings; } /* remember the device features */ rvdev->dfeatures = rsc->dfeatures; list_add_tail(&rvdev->node, &rproc->rvdevs); /* it is now safe to add the virtio device */ ret = rproc_add_virtio_dev(rvdev, rsc->id); if (ret) goto free_vrings; return 0; free_vrings: __rproc_free_vrings(rvdev, i); kfree(rvdev); return ret; } /** * rproc_handle_trace() - handle a shared trace buffer resource * @rproc: the remote processor * @rsc: the trace resource descriptor * @avail: size of available data (for sanity checking the image) * * In case the remote processor dumps trace logs into memory, * export it via debugfs. * * Currently, the 'da' member of @rsc should contain the device address * where the remote processor is dumping the traces. Later we could also * support dynamically allocating this address using the generic * DMA API (but currently there isn't a use case for that). * * Returns 0 on success, or an appropriate error code otherwise */ static int rproc_handle_trace(struct rproc *rproc, struct fw_rsc_trace *rsc, int avail) { struct rproc_mem_entry *trace; struct device *dev = rproc->dev; void *ptr; char name[15]; if (sizeof(*rsc) > avail) { dev_err(rproc->dev, "trace rsc is truncated\n"); return -EINVAL; } /* make sure reserved bytes are zeroes */ if (rsc->reserved) { dev_err(dev, "trace rsc has non zero reserved bytes\n"); return -EINVAL; } /* what's the kernel address of this resource ? */ ptr = rproc_da_to_va(rproc, rsc->da, rsc->len); if (!ptr) { dev_err(dev, "erroneous trace resource entry\n"); return -EINVAL; } trace = kzalloc(sizeof(*trace), GFP_KERNEL); if (!trace) { dev_err(dev, "kzalloc trace failed\n"); return -ENOMEM; } /* set the trace buffer dma properties */ trace->len = rsc->len; trace->va = ptr; /* make sure snprintf always null terminates, even if truncating */ snprintf(name, sizeof(name), "trace%d", rproc->num_traces); /* create the debugfs entry */ trace->priv = rproc_create_trace_file(name, rproc, trace); if (!trace->priv) { trace->va = NULL; kfree(trace); return -EINVAL; } list_add_tail(&trace->node, &rproc->traces); rproc->num_traces++; dev_dbg(dev, "%s added: va %p, da 0x%x, len 0x%x\n", name, ptr, rsc->da, rsc->len); return 0; } /** * rproc_handle_devmem() - handle devmem resource entry * @rproc: remote processor handle * @rsc: the devmem resource entry * @avail: size of available data (for sanity checking the image) * * Remote processors commonly need to access certain on-chip peripherals. * * Some of these remote processors access memory via an iommu device, * and might require us to configure their iommu before they can access * the on-chip peripherals they need. * * This resource entry is a request to map such a peripheral device. * * These devmem entries will contain the physical address of the device in * the 'pa' member. If a specific device address is expected, then 'da' will * contain it (currently this is the only use case supported). 'len' will * contain the size of the physical region we need to map. * * Currently we just "trust" those devmem entries to contain valid physical * addresses, but this is going to change: we want the implementations to * tell us ranges of physical addresses the firmware is allowed to request, * and not allow firmwares to request access to physical addresses that * are outside those ranges. */ static int rproc_handle_devmem(struct rproc *rproc, struct fw_rsc_devmem *rsc, int avail) { struct rproc_mem_entry *mapping; int ret; /* no point in handling this resource without a valid iommu domain */ if (!rproc->domain) return -EINVAL; if (sizeof(*rsc) > avail) { dev_err(rproc->dev, "devmem rsc is truncated\n"); return -EINVAL; } /* make sure reserved bytes are zeroes */ if (rsc->reserved) { dev_err(rproc->dev, "devmem rsc has non zero reserved bytes\n"); return -EINVAL; } mapping = kzalloc(sizeof(*mapping), GFP_KERNEL); if (!mapping) { dev_err(rproc->dev, "kzalloc mapping failed\n"); return -ENOMEM; } ret = iommu_map(rproc->domain, rsc->da, rsc->pa, rsc->len, rsc->flags); if (ret) { dev_err(rproc->dev, "failed to map devmem: %d\n", ret); goto out; } /* * We'll need this info later when we'll want to unmap everything * (e.g. on shutdown). * * We can't trust the remote processor not to change the resource * table, so we must maintain this info independently. */ mapping->da = rsc->da; mapping->len = rsc->len; list_add_tail(&mapping->node, &rproc->mappings); dev_dbg(rproc->dev, "mapped devmem pa 0x%x, da 0x%x, len 0x%x\n", rsc->pa, rsc->da, rsc->len); return 0; out: kfree(mapping); return ret; } /** * rproc_handle_carveout() - handle phys contig memory allocation requests * @rproc: rproc handle * @rsc: the resource entry * @avail: size of available data (for image validation) * * This function will handle firmware requests for allocation of physically * contiguous memory regions. * * These request entries should come first in the firmware's resource table, * as other firmware entries might request placing other data objects inside * these memory regions (e.g. data/code segments, trace resource entries, ...). * * Allocating memory this way helps utilizing the reserved physical memory * (e.g. CMA) more efficiently, and also minimizes the number of TLB entries * needed to map it (in case @rproc is using an IOMMU). Reducing the TLB * pressure is important; it may have a substantial impact on performance. */ static int rproc_handle_carveout(struct rproc *rproc, struct fw_rsc_carveout *rsc, int avail) { struct rproc_mem_entry *carveout, *mapping; struct device *dev = rproc->dev; dma_addr_t dma; void *va; int ret; if (sizeof(*rsc) > avail) { dev_err(rproc->dev, "carveout rsc is truncated\n"); return -EINVAL; } /* make sure reserved bytes are zeroes */ if (rsc->reserved) { dev_err(dev, "carveout rsc has non zero reserved bytes\n"); return -EINVAL; } dev_dbg(dev, "carveout rsc: da %x, pa %x, len %x, flags %x\n", rsc->da, rsc->pa, rsc->len, rsc->flags); mapping = kzalloc(sizeof(*mapping), GFP_KERNEL); if (!mapping) { dev_err(dev, "kzalloc mapping failed\n"); return -ENOMEM; } carveout = kzalloc(sizeof(*carveout), GFP_KERNEL); if (!carveout) { dev_err(dev, "kzalloc carveout failed\n"); ret = -ENOMEM; goto free_mapping; } va = dma_alloc_coherent(dev, rsc->len, &dma, GFP_KERNEL); if (!va) { dev_err(dev, "failed to dma alloc carveout: %d\n", rsc->len); ret = -ENOMEM; goto free_carv; } dev_dbg(dev, "carveout va %p, dma %x, len 0x%x\n", va, dma, rsc->len); /* * Ok, this is non-standard. * * Sometimes we can't rely on the generic iommu-based DMA API * to dynamically allocate the device address and then set the IOMMU * tables accordingly, because some remote processors might * _require_ us to use hard coded device addresses that their * firmware was compiled with. * * In this case, we must use the IOMMU API directly and map * the memory to the device address as expected by the remote * processor. * * Obviously such remote processor devices should not be configured * to use the iommu-based DMA API: we expect 'dma' to contain the * physical address in this case. */ if (rproc->domain) { ret = iommu_map(rproc->domain, rsc->da, dma, rsc->len, rsc->flags); if (ret) { dev_err(dev, "iommu_map failed: %d\n", ret); goto dma_free; } /* * We'll need this info later when we'll want to unmap * everything (e.g. on shutdown). * * We can't trust the remote processor not to change the * resource table, so we must maintain this info independently. */ mapping->da = rsc->da; mapping->len = rsc->len; list_add_tail(&mapping->node, &rproc->mappings); dev_dbg(dev, "carveout mapped 0x%x to 0x%x\n", rsc->da, dma); /* * Some remote processors might need to know the pa * even though they are behind an IOMMU. E.g., OMAP4's * remote M3 processor needs this so it can control * on-chip hardware accelerators that are not behind * the IOMMU, and therefor must know the pa. * * Generally we don't want to expose physical addresses * if we don't have to (remote processors are generally * _not_ trusted), so we might want to do this only for * remote processor that _must_ have this (e.g. OMAP4's * dual M3 subsystem). */ rsc->pa = dma; } carveout->va = va; carveout->len = rsc->len; carveout->dma = dma; carveout->da = rsc->da; list_add_tail(&carveout->node, &rproc->carveouts); return 0; dma_free: dma_free_coherent(dev, rsc->len, va, dma); free_carv: kfree(carveout); free_mapping: kfree(mapping); return ret; } /* * A lookup table for resource handlers. The indices are defined in * enum fw_resource_type. */ static rproc_handle_resource_t rproc_handle_rsc[] = { [RSC_CARVEOUT] = (rproc_handle_resource_t)rproc_handle_carveout, [RSC_DEVMEM] = (rproc_handle_resource_t)rproc_handle_devmem, [RSC_TRACE] = (rproc_handle_resource_t)rproc_handle_trace, [RSC_VDEV] = NULL, /* VDEVs were handled upon registrarion */ }; /* handle firmware resource entries before booting the remote processor */ static int rproc_handle_boot_rsc(struct rproc *rproc, struct resource_table *table, int len) { struct device *dev = rproc->dev; rproc_handle_resource_t handler; int ret = 0, i; for (i = 0; i < table->num; i++) { int offset = table->offset[i]; struct fw_rsc_hdr *hdr = (void *)table + offset; int avail = len - offset - sizeof(*hdr); void *rsc = (void *)hdr + sizeof(*hdr); /* make sure table isn't truncated */ if (avail < 0) { dev_err(dev, "rsc table is truncated\n"); return -EINVAL; } dev_dbg(dev, "rsc: type %d\n", hdr->type); if (hdr->type >= RSC_LAST) { dev_warn(dev, "unsupported resource %d\n", hdr->type); continue; } handler = rproc_handle_rsc[hdr->type]; if (!handler) continue; ret = handler(rproc, rsc, avail); if (ret) break; } return ret; } /* handle firmware resource entries while registering the remote processor */ static int rproc_handle_virtio_rsc(struct rproc *rproc, struct resource_table *table, int len) { struct device *dev = rproc->dev; int ret = 0, i; for (i = 0; i < table->num; i++) { int offset = table->offset[i]; struct fw_rsc_hdr *hdr = (void *)table + offset; int avail = len - offset - sizeof(*hdr); struct fw_rsc_vdev *vrsc; /* make sure table isn't truncated */ if (avail < 0) { dev_err(dev, "rsc table is truncated\n"); return -EINVAL; } dev_dbg(dev, "%s: rsc type %d\n", __func__, hdr->type); if (hdr->type != RSC_VDEV) continue; vrsc = (struct fw_rsc_vdev *)hdr->data; ret = rproc_handle_vdev(rproc, vrsc, avail); if (ret) break; } return ret; } /** * rproc_find_rsc_table() - find the resource table * @rproc: the rproc handle * @elf_data: the content of the ELF firmware image * @len: firmware size (in bytes) * @tablesz: place holder for providing back the table size * * This function finds the resource table inside the remote processor's * firmware. It is used both upon the registration of @rproc (in order * to look for and register the supported virito devices), and when the * @rproc is booted. * * Returns the pointer to the resource table if it is found, and write its * size into @tablesz. If a valid table isn't found, NULL is returned * (and @tablesz isn't set). */ static struct resource_table * rproc_find_rsc_table(struct rproc *rproc, const u8 *elf_data, size_t len, int *tablesz) { struct elf32_hdr *ehdr; struct elf32_shdr *shdr; const char *name_table; struct device *dev = rproc->dev; struct resource_table *table = NULL; int i; ehdr = (struct elf32_hdr *)elf_data; shdr = (struct elf32_shdr *)(elf_data + ehdr->e_shoff); name_table = elf_data + shdr[ehdr->e_shstrndx].sh_offset; /* look for the resource table and handle it */ for (i = 0; i < ehdr->e_shnum; i++, shdr++) { int size = shdr->sh_size; int offset = shdr->sh_offset; if (strcmp(name_table + shdr->sh_name, ".resource_table")) continue; table = (struct resource_table *)(elf_data + offset); /* make sure we have the entire table */ if (offset + size > len) { dev_err(dev, "resource table truncated\n"); return NULL; } /* make sure table has at least the header */ if (sizeof(struct resource_table) > size) { dev_err(dev, "header-less resource table\n"); return NULL; } /* we don't support any version beyond the first */ if (table->ver != 1) { dev_err(dev, "unsupported fw ver: %d\n", table->ver); return NULL; } /* make sure reserved bytes are zeroes */ if (table->reserved[0] || table->reserved[1]) { dev_err(dev, "non zero reserved bytes\n"); return NULL; } /* make sure the offsets array isn't truncated */ if (table->num * sizeof(table->offset[0]) + sizeof(struct resource_table) > size) { dev_err(dev, "resource table incomplete\n"); return NULL; } *tablesz = shdr->sh_size; break; } return table; } /** * rproc_resource_cleanup() - clean up and free all acquired resources * @rproc: rproc handle * * This function will free all resources acquired for @rproc, and it * is called whenever @rproc either shuts down or fails to boot. */ static void rproc_resource_cleanup(struct rproc *rproc) { struct rproc_mem_entry *entry, *tmp; struct device *dev = rproc->dev; /* clean up debugfs trace entries */ list_for_each_entry_safe(entry, tmp, &rproc->traces, node) { rproc_remove_trace_file(entry->priv); rproc->num_traces--; list_del(&entry->node); kfree(entry); } /* clean up carveout allocations */ list_for_each_entry_safe(entry, tmp, &rproc->carveouts, node) { dma_free_coherent(dev, entry->len, entry->va, entry->dma); list_del(&entry->node); kfree(entry); } /* clean up iommu mapping entries */ list_for_each_entry_safe(entry, tmp, &rproc->mappings, node) { size_t unmapped; unmapped = iommu_unmap(rproc->domain, entry->da, entry->len); if (unmapped != entry->len) { /* nothing much to do besides complaining */ dev_err(dev, "failed to unmap %u/%u\n", entry->len, unmapped); } list_del(&entry->node); kfree(entry); } } /* make sure this fw image is sane */ static int rproc_fw_sanity_check(struct rproc *rproc, const struct firmware *fw) { const char *name = rproc->firmware; struct device *dev = rproc->dev; struct elf32_hdr *ehdr; char class; if (!fw) { dev_err(dev, "failed to load %s\n", name); return -EINVAL; } if (fw->size < sizeof(struct elf32_hdr)) { dev_err(dev, "Image is too small\n"); return -EINVAL; } ehdr = (struct elf32_hdr *)fw->data; /* We only support ELF32 at this point */ class = ehdr->e_ident[EI_CLASS]; if (class != ELFCLASS32) { dev_err(dev, "Unsupported class: %d\n", class); return -EINVAL; } /* We assume the firmware has the same endianess as the host */ # ifdef __LITTLE_ENDIAN if (ehdr->e_ident[EI_DATA] != ELFDATA2LSB) { # else /* BIG ENDIAN */ if (ehdr->e_ident[EI_DATA] != ELFDATA2MSB) { # endif dev_err(dev, "Unsupported firmware endianess\n"); return -EINVAL; } if (fw->size < ehdr->e_shoff + sizeof(struct elf32_shdr)) { dev_err(dev, "Image is too small\n"); return -EINVAL; } if (memcmp(ehdr->e_ident, ELFMAG, SELFMAG)) { dev_err(dev, "Image is corrupted (bad magic)\n"); return -EINVAL; } if (ehdr->e_phnum == 0) { dev_err(dev, "No loadable segments\n"); return -EINVAL; } if (ehdr->e_phoff > fw->size) { dev_err(dev, "Firmware size is too small\n"); return -EINVAL; } return 0; } /* * take a firmware and boot a remote processor with it. */ static int rproc_fw_boot(struct rproc *rproc, const struct firmware *fw) { struct device *dev = rproc->dev; const char *name = rproc->firmware; struct elf32_hdr *ehdr; struct resource_table *table; int ret, tablesz; ret = rproc_fw_sanity_check(rproc, fw); if (ret) return ret; ehdr = (struct elf32_hdr *)fw->data; dev_info(dev, "Booting fw image %s, size %d\n", name, fw->size); /* * if enabling an IOMMU isn't relevant for this rproc, this is * just a nop */ ret = rproc_enable_iommu(rproc); if (ret) { dev_err(dev, "can't enable iommu: %d\n", ret); return ret; } /* * The ELF entry point is the rproc's boot addr (though this is not * a configurable property of all remote processors: some will always * boot at a specific hardcoded address). */ rproc->bootaddr = ehdr->e_entry; /* look for the resource table */ table = rproc_find_rsc_table(rproc, fw->data, fw->size, &tablesz); if (!table) goto clean_up; /* handle fw resources which are required to boot rproc */ ret = rproc_handle_boot_rsc(rproc, table, tablesz); if (ret) { dev_err(dev, "Failed to process resources: %d\n", ret); goto clean_up; } /* load the ELF segments to memory */ ret = rproc_load_segments(rproc, fw->data, fw->size); if (ret) { dev_err(dev, "Failed to load program segments: %d\n", ret); goto clean_up; } /* power up the remote processor */ ret = rproc->ops->start(rproc); if (ret) { dev_err(dev, "can't start rproc %s: %d\n", rproc->name, ret); goto clean_up; } rproc->state = RPROC_RUNNING; dev_info(dev, "remote processor %s is now up\n", rproc->name); return 0; clean_up: rproc_resource_cleanup(rproc); rproc_disable_iommu(rproc); return ret; } /* * take a firmware and look for virtio devices to register. * * Note: this function is called asynchronously upon registration of the * remote processor (so we must wait until it completes before we try * to unregister the device. one other option is just to use kref here, * that might be cleaner). */ static void rproc_fw_config_virtio(const struct firmware *fw, void *context) { struct rproc *rproc = context; struct resource_table *table; int ret, tablesz; if (rproc_fw_sanity_check(rproc, fw) < 0) goto out; /* look for the resource table */ table = rproc_find_rsc_table(rproc, fw->data, fw->size, &tablesz); if (!table) goto out; /* look for virtio devices and register them */ ret = rproc_handle_virtio_rsc(rproc, table, tablesz); if (ret) goto out; out: if (fw) release_firmware(fw); /* allow rproc_unregister() contexts, if any, to proceed */ complete_all(&rproc->firmware_loading_complete); } /** * rproc_boot() - boot a remote processor * @rproc: handle of a remote processor * * Boot a remote processor (i.e. load its firmware, power it on, ...). * * If the remote processor is already powered on, this function immediately * returns (successfully). * * Returns 0 on success, and an appropriate error value otherwise. */ int rproc_boot(struct rproc *rproc) { const struct firmware *firmware_p; struct device *dev; int ret; if (!rproc) { pr_err("invalid rproc handle\n"); return -EINVAL; } dev = rproc->dev; ret = mutex_lock_interruptible(&rproc->lock); if (ret) { dev_err(dev, "can't lock rproc %s: %d\n", rproc->name, ret); return ret; } /* loading a firmware is required */ if (!rproc->firmware) { dev_err(dev, "%s: no firmware to load\n", __func__); ret = -EINVAL; goto unlock_mutex; } /* prevent underlying implementation from being removed */ if (!try_module_get(dev->driver->owner)) { dev_err(dev, "%s: can't get owner\n", __func__); ret = -EINVAL; goto unlock_mutex; } /* skip the boot process if rproc is already powered up */ if (atomic_inc_return(&rproc->power) > 1) { ret = 0; goto unlock_mutex; } dev_info(dev, "powering up %s\n", rproc->name); /* load firmware */ ret = request_firmware(&firmware_p, rproc->firmware, dev); if (ret < 0) { dev_err(dev, "request_firmware failed: %d\n", ret); goto downref_rproc; } ret = rproc_fw_boot(rproc, firmware_p); release_firmware(firmware_p); downref_rproc: if (ret) { module_put(dev->driver->owner); atomic_dec(&rproc->power); } unlock_mutex: mutex_unlock(&rproc->lock); return ret; } EXPORT_SYMBOL(rproc_boot); /** * rproc_shutdown() - power off the remote processor * @rproc: the remote processor * * Power off a remote processor (previously booted with rproc_boot()). * * In case @rproc is still being used by an additional user(s), then * this function will just decrement the power refcount and exit, * without really powering off the device. * * Every call to rproc_boot() must (eventually) be accompanied by a call * to rproc_shutdown(). Calling rproc_shutdown() redundantly is a bug. * * Notes: * - we're not decrementing the rproc's refcount, only the power refcount. * which means that the @rproc handle stays valid even after rproc_shutdown() * returns, and users can still use it with a subsequent rproc_boot(), if * needed. * - don't call rproc_shutdown() to unroll rproc_get_by_name(), exactly * because rproc_shutdown() _does not_ decrement the refcount of @rproc. * To decrement the refcount of @rproc, use rproc_put() (but _only_ if * you acquired @rproc using rproc_get_by_name()). */ void rproc_shutdown(struct rproc *rproc) { struct device *dev = rproc->dev; int ret; ret = mutex_lock_interruptible(&rproc->lock); if (ret) { dev_err(dev, "can't lock rproc %s: %d\n", rproc->name, ret); return; } /* if the remote proc is still needed, bail out */ if (!atomic_dec_and_test(&rproc->power)) goto out; /* power off the remote processor */ ret = rproc->ops->stop(rproc); if (ret) { atomic_inc(&rproc->power); dev_err(dev, "can't stop rproc: %d\n", ret); goto out; } /* clean up all acquired resources */ rproc_resource_cleanup(rproc); rproc_disable_iommu(rproc); rproc->state = RPROC_OFFLINE; dev_info(dev, "stopped remote processor %s\n", rproc->name); out: mutex_unlock(&rproc->lock); if (!ret) module_put(dev->driver->owner); } EXPORT_SYMBOL(rproc_shutdown); /** * rproc_release() - completely deletes the existence of a remote processor * @kref: the rproc's kref * * This function should _never_ be called directly. * * The only reasonable location to use it is as an argument when kref_put'ing * @rproc's refcount. * * This way it will be called when no one holds a valid pointer to this @rproc * anymore (and obviously after it is removed from the rprocs klist). * * Note: this function is not static because rproc_vdev_release() needs it when * it decrements @rproc's refcount. */ void rproc_release(struct kref *kref) { struct rproc *rproc = container_of(kref, struct rproc, refcount); struct rproc_vdev *rvdev, *rvtmp; dev_info(rproc->dev, "removing %s\n", rproc->name); rproc_delete_debug_dir(rproc); /* clean up remote vdev entries */ list_for_each_entry_safe(rvdev, rvtmp, &rproc->rvdevs, node) { __rproc_free_vrings(rvdev, RVDEV_NUM_VRINGS); list_del(&rvdev->node); } /* * At this point no one holds a reference to rproc anymore, * so we can directly unroll rproc_alloc() */ rproc_free(rproc); } /* will be called when an rproc is added to the rprocs klist */ static void klist_rproc_get(struct klist_node *n) { struct rproc *rproc = container_of(n, struct rproc, node); kref_get(&rproc->refcount); } /* will be called when an rproc is removed from the rprocs klist */ static void klist_rproc_put(struct klist_node *n) { struct rproc *rproc = container_of(n, struct rproc, node); kref_put(&rproc->refcount, rproc_release); } static struct rproc *next_rproc(struct klist_iter *i) { struct klist_node *n; n = klist_next(i); if (!n) return NULL; return container_of(n, struct rproc, node); } /** * rproc_get_by_name() - find a remote processor by name and boot it * @name: name of the remote processor * * Finds an rproc handle using the remote processor's name, and then * boot it. If it's already powered on, then just immediately return * (successfully). * * Returns the rproc handle on success, and NULL on failure. * * This function increments the remote processor's refcount, so always * use rproc_put() to decrement it back once rproc isn't needed anymore. * * Note: currently this function (and its counterpart rproc_put()) are not * being used. We need to scrutinize the use cases * that still need them, and see if we can migrate them to use the non * name-based boot/shutdown interface. */ struct rproc *rproc_get_by_name(const char *name) { struct rproc *rproc; struct klist_iter i; int ret; /* find the remote processor, and upref its refcount */ klist_iter_init(&rprocs, &i); while ((rproc = next_rproc(&i)) != NULL) if (!strcmp(rproc->name, name)) { kref_get(&rproc->refcount); break; } klist_iter_exit(&i); /* can't find this rproc ? */ if (!rproc) { pr_err("can't find remote processor %s\n", name); return NULL; } ret = rproc_boot(rproc); if (ret < 0) { kref_put(&rproc->refcount, rproc_release); return NULL; } return rproc; } EXPORT_SYMBOL(rproc_get_by_name); /** * rproc_put() - decrement the refcount of a remote processor, and shut it down * @rproc: the remote processor * * This function tries to shutdown @rproc, and it then decrements its * refcount. * * After this function returns, @rproc may _not_ be used anymore, and its * handle should be considered invalid. * * This function should be called _iff_ the @rproc handle was grabbed by * calling rproc_get_by_name(). */ void rproc_put(struct rproc *rproc) { /* try to power off the remote processor */ rproc_shutdown(rproc); /* downref rproc's refcount */ kref_put(&rproc->refcount, rproc_release); } EXPORT_SYMBOL(rproc_put); /** * rproc_register() - register a remote processor * @rproc: the remote processor handle to register * * Registers @rproc with the remoteproc framework, after it has been * allocated with rproc_alloc(). * * This is called by the platform-specific rproc implementation, whenever * a new remote processor device is probed. * * Returns 0 on success and an appropriate error code otherwise. * * Note: this function initiates an asynchronous firmware loading * context, which will look for virtio devices supported by the rproc's * firmware. * * If found, those virtio devices will be created and added, so as a result * of registering this remote processor, additional virtio drivers might be * probed. */ int rproc_register(struct rproc *rproc) { struct device *dev = rproc->dev; int ret = 0; /* expose to rproc_get_by_name users */ klist_add_tail(&rproc->node, &rprocs); dev_info(rproc->dev, "%s is available\n", rproc->name); dev_info(dev, "Note: remoteproc is still under development and considered experimental.\n"); dev_info(dev, "THE BINARY FORMAT IS NOT YET FINALIZED, and backward compatibility isn't yet guaranteed.\n"); /* create debugfs entries */ rproc_create_debug_dir(rproc); /* rproc_unregister() calls must wait until async loader completes */ init_completion(&rproc->firmware_loading_complete); /* * We must retrieve early virtio configuration info from * the firmware (e.g. whether to register a virtio device, * what virtio features does it support, ...). * * We're initiating an asynchronous firmware loading, so we can * be built-in kernel code, without hanging the boot process. */ ret = request_firmware_nowait(THIS_MODULE, FW_ACTION_HOTPLUG, rproc->firmware, dev, GFP_KERNEL, rproc, rproc_fw_config_virtio); if (ret < 0) { dev_err(dev, "request_firmware_nowait failed: %d\n", ret); complete_all(&rproc->firmware_loading_complete); klist_remove(&rproc->node); } return ret; } EXPORT_SYMBOL(rproc_register); /** * rproc_alloc() - allocate a remote processor handle * @dev: the underlying device * @name: name of this remote processor * @ops: platform-specific handlers (mainly start/stop) * @firmware: name of firmware file to load * @len: length of private data needed by the rproc driver (in bytes) * * Allocates a new remote processor handle, but does not register * it yet. * * This function should be used by rproc implementations during initialization * of the remote processor. * * After creating an rproc handle using this function, and when ready, * implementations should then call rproc_register() to complete * the registration of the remote processor. * * On success the new rproc is returned, and on failure, NULL. * * Note: _never_ directly deallocate @rproc, even if it was not registered * yet. Instead, if you just need to unroll rproc_alloc(), use rproc_free(). */ struct rproc *rproc_alloc(struct device *dev, const char *name, const struct rproc_ops *ops, const char *firmware, int len) { struct rproc *rproc; if (!dev || !name || !ops) return NULL; rproc = kzalloc(sizeof(struct rproc) + len, GFP_KERNEL); if (!rproc) { dev_err(dev, "%s: kzalloc failed\n", __func__); return NULL; } rproc->dev = dev; rproc->name = name; rproc->ops = ops; rproc->firmware = firmware; rproc->priv = &rproc[1]; atomic_set(&rproc->power, 0); kref_init(&rproc->refcount); mutex_init(&rproc->lock); idr_init(&rproc->notifyids); INIT_LIST_HEAD(&rproc->carveouts); INIT_LIST_HEAD(&rproc->mappings); INIT_LIST_HEAD(&rproc->traces); INIT_LIST_HEAD(&rproc->rvdevs); rproc->state = RPROC_OFFLINE; return rproc; } EXPORT_SYMBOL(rproc_alloc); /** * rproc_free() - free an rproc handle that was allocated by rproc_alloc * @rproc: the remote processor handle * * This function should _only_ be used if @rproc was only allocated, * but not registered yet. * * If @rproc was already successfully registered (by calling rproc_register()), * then use rproc_unregister() instead. */ void rproc_free(struct rproc *rproc) { idr_remove_all(&rproc->notifyids); idr_destroy(&rproc->notifyids); kfree(rproc); } EXPORT_SYMBOL(rproc_free); /** * rproc_unregister() - unregister a remote processor * @rproc: rproc handle to unregister * * Unregisters a remote processor, and decrements its refcount. * If its refcount drops to zero, then @rproc will be freed. If not, * it will be freed later once the last reference is dropped. * * This function should be called when the platform specific rproc * implementation decides to remove the rproc device. it should * _only_ be called if a previous invocation of rproc_register() * has completed successfully. * * After rproc_unregister() returns, @rproc is _not_ valid anymore and * it shouldn't be used. More specifically, don't call rproc_free() * or try to directly free @rproc after rproc_unregister() returns; * none of these are needed, and calling them is a bug. * * Returns 0 on success and -EINVAL if @rproc isn't valid. */ int rproc_unregister(struct rproc *rproc) { struct rproc_vdev *rvdev; if (!rproc) return -EINVAL; /* if rproc is just being registered, wait */ wait_for_completion(&rproc->firmware_loading_complete); /* clean up remote vdev entries */ list_for_each_entry(rvdev, &rproc->rvdevs, node) rproc_remove_virtio_dev(rvdev); /* the rproc is downref'ed as soon as it's removed from the klist */ klist_del(&rproc->node); /* the rproc will only be released after its refcount drops to zero */ kref_put(&rproc->refcount, rproc_release); return 0; } EXPORT_SYMBOL(rproc_unregister); static int __init remoteproc_init(void) { rproc_init_debugfs(); return 0; } module_init(remoteproc_init); static void __exit remoteproc_exit(void) { rproc_exit_debugfs(); } module_exit(remoteproc_exit); MODULE_LICENSE("GPL v2"); MODULE_DESCRIPTION("Generic Remote Processor Framework");