diff options
Diffstat (limited to 'drivers/remoteproc/remoteproc_core.c')
| -rw-r--r-- | drivers/remoteproc/remoteproc_core.c | 1586 |
1 files changed, 1586 insertions, 0 deletions
diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c new file mode 100644 index 00000000000..ee15c68fb51 --- /dev/null +++ b/drivers/remoteproc/remoteproc_core.c @@ -0,0 +1,1586 @@ +/* + * 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 <asm/byteorder.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() 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) +{ + 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); + + 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"); |