diff options
Diffstat (limited to 'drivers/remoteproc/remoteproc_core.c')
| -rw-r--r-- | drivers/remoteproc/remoteproc_core.c | 1410 |
1 files changed, 1410 insertions, 0 deletions
diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c new file mode 100644 index 000000000000..ad93d7d4ecbb --- /dev/null +++ b/drivers/remoteproc/remoteproc_core.c @@ -0,0 +1,1410 @@ +/* + * Remote Processor Framework + * + * Copyright (C) 2011 Texas Instruments, Inc. + * Copyright (C) 2011 Google, Inc. + * + * Ohad Ben-Cohen <ohad@wizery.com> + * Brian Swetland <swetland@google.com> + * Mark Grosen <mgrosen@ti.com> + * Fernando Guzman Lugo <fernando.lugo@ti.com> + * Suman Anna <s-anna@ti.com> + * Robert Tivy <rtivy@ti.com> + * Armando Uribe De Leon <x0095078@ti.com> + * + * 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 <linux/kernel.h> +#include <linux/module.h> +#include <linux/device.h> +#include <linux/slab.h> +#include <linux/mutex.h> +#include <linux/dma-mapping.h> +#include <linux/firmware.h> +#include <linux/string.h> +#include <linux/debugfs.h> +#include <linux/remoteproc.h> +#include <linux/iommu.h> +#include <linux/klist.h> +#include <linux/elf.h> +#include <linux/virtio_ids.h> +#include <linux/virtio_ring.h> + +#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() anymore within the rpmsg + * framework. 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 fw_resource *rsc, int len); + +/* + * 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) +{ + 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_err(dev, "iommu not found\n"); + return -ENODEV; + } + + 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); + + 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 + * + * 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) +{ + 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; + 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; + } + + /* 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; +} + +/** + * rproc_handle_virtio_hdr() - handle a virtio header resource + * @rproc: the remote processor + * @rsc: the resource descriptor + * + * The existence of this virtio hdr resource entry means that the firmware + * of this @rproc supports this virtio device. + * + * Currently we support only a single virtio device of type VIRTIO_ID_RPMSG, + * but the plan is to remove this limitation and support any number + * of virtio devices (and of any type). We'll also add support for dynamically + * adding (and removing) virtio devices over the rpmsg bus, but small + * firmwares that doesn't want to get involved with rpmsg will be able + * to simple use the resource table for this. + * + * At this point this virtio header entry is rather simple: it just + * announces the virtio device id and the supported virtio device features. + * The plan though is to extend this to include the vring information and + * the virtio config space, too (but first, some resource table overhaul + * is needed: move from fixed-sized to variable-length TLV entries). + * + * For now, the 'flags' member of the resource entry contains the virtio + * device id, the 'da' member contains the device features, and 'pa' is + * where we need to store the guest features once negotiation completes. + * As usual, the 'id' member of this resource contains the index of this + * resource type (i.e. is this the first virtio hdr entry, the 2nd, ...). + * + * Returns 0 on success, or an appropriate error code otherwise + */ +static int rproc_handle_virtio_hdr(struct rproc *rproc, struct fw_resource *rsc) +{ + struct rproc_vdev *rvdev; + + /* we only support VIRTIO_ID_RPMSG devices for now */ + if (rsc->flags != VIRTIO_ID_RPMSG) { + dev_warn(rproc->dev, "unsupported vdev: %d\n", rsc->flags); + return -EINVAL; + } + + /* we only support a single vdev per rproc for now */ + if (rsc->id || rproc->rvdev) { + dev_warn(rproc->dev, "redundant vdev entry: %s\n", rsc->name); + return -EINVAL; + } + + rvdev = kzalloc(sizeof(struct rproc_vdev), GFP_KERNEL); + if (!rvdev) + return -ENOMEM; + + /* remember the device features */ + rvdev->dfeatures = rsc->da; + + rproc->rvdev = rvdev; + rvdev->rproc = rproc; + + return 0; +} + +/** + * rproc_handle_vring() - handle a vring fw resource + * @rproc: the remote processor + * @rsc: the vring resource descriptor + * + * This resource entry requires allocation of non-cacheable memory + * for a virtio vring. Currently we only support two vrings per remote + * processor, required for the virtio rpmsg device. + * + * The 'len' member of @rsc should contain the number of buffers this vring + * support and 'da' should either contain the device address where + * the remote processor is expecting the vring, or indicate that + * dynamically allocation of the vring's device address is supported. + * + * Note: 'da' is currently not handled. This will be revised when the generic + * iommu-based DMA API will arrive, or a dynanic & non-iommu use case show + * up. Meanwhile, statically-addressed iommu-based images should use + * RSC_DEVMEM resource entries to map their require 'da' to the physical + * address of their base CMA region. + * + * Returns 0 on success, or an appropriate error code otherwise + */ +static int rproc_handle_vring(struct rproc *rproc, struct fw_resource *rsc) +{ + struct device *dev = rproc->dev; + struct rproc_vdev *rvdev = rproc->rvdev; + dma_addr_t dma; + int size, id = rsc->id; + void *va; + + /* no vdev is in place ? */ + if (!rvdev) { + dev_err(dev, "vring requested without a virtio dev entry\n"); + return -EINVAL; + } + + /* the firmware must provide the expected queue size */ + if (!rsc->len) { + dev_err(dev, "missing expected queue size\n"); + return -EINVAL; + } + + /* we currently support two vrings per rproc (for rx and tx) */ + if (id >= ARRAY_SIZE(rvdev->vring)) { + dev_err(dev, "%s: invalid vring id %d\n", rsc->name, id); + return -EINVAL; + } + + /* have we already allocated this vring id ? */ + if (rvdev->vring[id].len) { + dev_err(dev, "%s: duplicated id %d\n", rsc->name, id); + return -EINVAL; + } + + /* actual size of vring (in bytes) */ + size = PAGE_ALIGN(vring_size(rsc->len, AMP_VRING_ALIGN)); + + /* + * 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 -ENOMEM; + } + + dev_dbg(dev, "vring%d: va %p dma %x qsz %d ring size %x\n", id, va, + dma, rsc->len, size); + + rvdev->vring[id].len = rsc->len; + rvdev->vring[id].va = va; + rvdev->vring[id].dma = dma; + + return 0; +} + +/** + * rproc_handle_trace() - handle a shared trace buffer resource + * @rproc: the remote processor + * @rsc: the trace resource descriptor + * + * 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_resource *rsc) +{ + struct rproc_mem_entry *trace; + struct device *dev = rproc->dev; + void *ptr; + char name[15]; + + /* 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%llx, 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 + * + * 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_resource *rsc) +{ + struct rproc_mem_entry *mapping; + int ret; + + /* no point in handling this resource without a valid iommu domain */ + if (!rproc->domain) + 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%llx, da 0x%llx, 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 + * + * 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_resource *rsc) +{ + struct rproc_mem_entry *carveout, *mapping; + struct device *dev = rproc->dev; + dma_addr_t dma; + void *va; + int ret; + + 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%llx 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; +} + +/* handle firmware resource entries before booting the remote processor */ +static int +rproc_handle_boot_rsc(struct rproc *rproc, struct fw_resource *rsc, int len) +{ + struct device *dev = rproc->dev; + int ret = 0; + + while (len >= sizeof(*rsc)) { + dev_dbg(dev, "rsc: type %d, da 0x%llx, pa 0x%llx, len 0x%x, " + "id %d, name %s, flags %x\n", rsc->type, rsc->da, + rsc->pa, rsc->len, rsc->id, rsc->name, rsc->flags); + + switch (rsc->type) { + case RSC_CARVEOUT: + ret = rproc_handle_carveout(rproc, rsc); + break; + case RSC_DEVMEM: + ret = rproc_handle_devmem(rproc, rsc); + break; + case RSC_TRACE: + ret = rproc_handle_trace(rproc, rsc); + break; + case RSC_VRING: + ret = rproc_handle_vring(rproc, rsc); + break; + case RSC_VIRTIO_DEV: + /* this one is handled early upon registration */ + break; + default: + dev_warn(dev, "unsupported resource %d\n", rsc->type); + break; + } + + if (ret) + break; + + rsc++; + len -= sizeof(*rsc); + } + + return ret; +} + +/* handle firmware resource entries while registering the remote processor */ +static int +rproc_handle_virtio_rsc(struct rproc *rproc, struct fw_resource *rsc, int len) +{ + struct device *dev = rproc->dev; + int ret = 0; + + for (; len >= sizeof(*rsc); rsc++, len -= sizeof(*rsc)) + if (rsc->type == RSC_VIRTIO_DEV) { + dev_dbg(dev, "found vdev %d/%s features %llx\n", + rsc->flags, rsc->name, rsc->da); + ret = rproc_handle_virtio_hdr(rproc, rsc); + break; + } + + return ret; +} + +/** + * rproc_handle_resources() - find and handle the resource table + * @rproc: the rproc handle + * @elf_data: the content of the ELF firmware image + * @handler: function that should be used to handle the resource table + * + * This function finds the resource table inside the remote processor's + * firmware, and invoke a user-supplied handler with it (we have two + * possible handlers: one is invoked upon registration of @rproc, + * in order to register the supported virito devices, and the other is + * invoked when @rproc is actually booted). + * + * Currently this function fails if a resource table doesn't exist. + * This restriction will be removed when we'll start supporting remote + * processors that don't need a resource table. + */ +static int rproc_handle_resources(struct rproc *rproc, const u8 *elf_data, + rproc_handle_resources_t handler) + +{ + struct elf32_hdr *ehdr; + struct elf32_shdr *shdr; + const char *name_table; + int i, ret = -EINVAL; + + 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++) { + if (!strcmp(name_table + shdr->sh_name, ".resource_table")) { + struct fw_resource *table = (struct fw_resource *) + (elf_data + shdr->sh_offset); + + ret = handler(rproc, table, shdr->sh_size); + + break; + } + } + + return ret; +} + +/** + * 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 when @rproc shuts down, or just failed booting. + */ +static void rproc_resource_cleanup(struct rproc *rproc) +{ + struct rproc_mem_entry *entry, *tmp; + struct device *dev = rproc->dev; + struct rproc_vdev *rvdev = rproc->rvdev; + int i; + + /* 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); + } + + /* free the coherent memory allocated for the vrings */ + for (i = 0; rvdev && i < ARRAY_SIZE(rvdev->vring); i++) { + int qsz = rvdev->vring[i].len; + void *va = rvdev->vring[i].va; + int dma = rvdev->vring[i].dma; + + /* virtqueue size is expressed in number of buffers supported */ + if (qsz) { + /* how many bytes does this vring really occupy ? */ + int size = PAGE_ALIGN(vring_size(qsz, AMP_VRING_ALIGN)); + + dma_free_coherent(rproc->dev, size, va, dma); + + rvdev->vring[i].len = 0; + } + } + + /* 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; + + 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; + + 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; + int ret; + + 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; + + /* handle fw resources which are required to boot rproc */ + ret = rproc_handle_resources(rproc, fw->data, rproc_handle_boot_rsc); + 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); + 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 device *dev = rproc->dev; + int ret; + + if (rproc_fw_sanity_check(rproc, fw) < 0) + goto out; + + /* does the fw supports any virtio devices ? */ + ret = rproc_handle_resources(rproc, fw->data, rproc_handle_virtio_rsc); + if (ret) { + dev_info(dev, "No fw virtio device was found\n"); + goto out; + } + + /* add the virtio device (currently only rpmsg vdevs are supported) */ + ret = rproc_add_rpmsg_vdev(rproc); + 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); + + dev_info(rproc->dev, "removing %s\n", rproc->name); + + rproc_delete_debug_dir(rproc); + + /* at this point no one holds a reference to rproc anymore */ + kfree(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 + * used anymore by the rpmsg subsystem. 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 will be + * probed. + * + * Currently, though, we only support a single RPMSG virtio vdev per remote + * processor. + */ +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); + + /* 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 rpmsg 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); + + INIT_LIST_HEAD(&rproc->carveouts); + INIT_LIST_HEAD(&rproc->mappings); + INIT_LIST_HEAD(&rproc->traces); + + 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) +{ + 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) +{ + if (!rproc) + return -EINVAL; + + /* if rproc is just being registered, wait */ + wait_for_completion(&rproc->firmware_loading_complete); + + /* was an rpmsg vdev created ? */ + if (rproc->rvdev) + rproc_remove_rpmsg_vdev(rproc); + + klist_remove(&rproc->node); + + 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"); |