/*
* 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() 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);
typedef int (*rproc_handle_resource_t)(struct rproc *rproc,
struct fw_resource *rsc);
/*
* 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;
}
/**
* 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;
}
/*
* 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_carveout,
[RSC_DEVMEM] = rproc_handle_devmem,
[RSC_TRACE] = rproc_handle_trace,
[RSC_VRING] = rproc_handle_vring,
[RSC_VIRTIO_DEV] = NULL, /* handled early upon registration */
};
/* 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;
rproc_handle_resource_t handler;
int ret = 0;
for (; len >= sizeof(*rsc); rsc++, 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);
if (rsc->type >= RSC_LAST) {
dev_warn(dev, "unsupported resource %d\n", rsc->type);
continue;
}
handler = rproc_handle_rsc[rsc->type];
if (!handler)
continue;
ret = handler(rproc, rsc);
if (ret)
break;
}
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 = -ENODEV;
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
* @len: firmware size (in bytes)
* @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,
size_t len, 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);
if (shdr->sh_offset + shdr->sh_size > len) {
dev_err(rproc->dev,
"truncated fw: need 0x%x avail 0x%x\n",
shdr->sh_offset + shdr->sh_size, len);
ret = -EINVAL;
}
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;
/* 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;
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, fw->size,
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, 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 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, fw->size,
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);
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 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");
