blob: 41a45ecb62b65dd4bf65955e91bfb2a3e31d1007 [file] [log] [blame]
/*
* Greybus Firmware Download Protocol Driver.
*
* Copyright 2016 Google Inc.
* Copyright 2016 Linaro Ltd.
*
* Released under the GPLv2 only.
*/
#include <linux/firmware.h>
#include <linux/jiffies.h>
#include <linux/mutex.h>
#include <linux/workqueue.h>
#include "firmware.h"
#include "greybus.h"
/* Estimated minimum buffer size, actual size can be smaller than this */
#define MIN_FETCH_SIZE 512
/* Timeout, in jiffies, within which fetch or release firmware must be called */
#define NEXT_REQ_TIMEOUT_J msecs_to_jiffies(1000)
struct fw_request {
u8 firmware_id;
bool disabled;
bool timedout;
char name[FW_NAME_LEN];
const struct firmware *fw;
struct list_head node;
struct delayed_work dwork;
/* Timeout, in jiffies, within which the firmware shall download */
unsigned long release_timeout_j;
struct kref kref;
struct fw_download *fw_download;
};
struct fw_download {
struct device *parent;
struct gb_connection *connection;
struct list_head fw_requests;
struct ida id_map;
struct mutex mutex;
};
static void fw_req_release(struct kref *kref)
{
struct fw_request *fw_req = container_of(kref, struct fw_request, kref);
dev_dbg(fw_req->fw_download->parent, "firmware %s released\n",
fw_req->name);
release_firmware(fw_req->fw);
/*
* The request timed out and the module may send a fetch-fw or
* release-fw request later. Lets block the id we allocated for this
* request, so that the AP doesn't refer to a later fw-request (with
* same firmware_id) for the old timedout fw-request.
*
* NOTE:
*
* This also means that after 255 timeouts we will fail to service new
* firmware downloads. But what else can we do in that case anyway? Lets
* just hope that it never happens.
*/
if (!fw_req->timedout)
ida_simple_remove(&fw_req->fw_download->id_map,
fw_req->firmware_id);
kfree(fw_req);
}
/*
* Incoming requests are serialized for a connection, and the only race possible
* is between the timeout handler freeing this and an incoming request.
*
* The operations on the fw-request list are protected by the mutex and
* get_fw_req() increments the reference count before returning a fw_req pointer
* to the users.
*
* free_firmware() also takes the mutex while removing an entry from the list,
* it guarantees that every user of fw_req has taken a kref-reference by now and
* we wouldn't have any new users.
*
* Once the last user drops the reference, the fw_req structure is freed.
*/
static void put_fw_req(struct fw_request *fw_req)
{
kref_put(&fw_req->kref, fw_req_release);
}
/* Caller must call put_fw_req() after using struct fw_request */
static struct fw_request *get_fw_req(struct fw_download *fw_download,
u8 firmware_id)
{
struct fw_request *fw_req;
mutex_lock(&fw_download->mutex);
list_for_each_entry(fw_req, &fw_download->fw_requests, node) {
if (fw_req->firmware_id == firmware_id) {
kref_get(&fw_req->kref);
goto unlock;
}
}
fw_req = NULL;
unlock:
mutex_unlock(&fw_download->mutex);
return fw_req;
}
static void free_firmware(struct fw_download *fw_download,
struct fw_request *fw_req)
{
/* Already disabled from timeout handlers */
if (fw_req->disabled)
return;
mutex_lock(&fw_download->mutex);
list_del(&fw_req->node);
mutex_unlock(&fw_download->mutex);
fw_req->disabled = true;
put_fw_req(fw_req);
}
static void fw_request_timedout(struct work_struct *work)
{
struct delayed_work *dwork = to_delayed_work(work);
struct fw_request *fw_req = container_of(dwork, struct fw_request, dwork);
struct fw_download *fw_download = fw_req->fw_download;
dev_err(fw_download->parent,
"Timed out waiting for fetch / release firmware requests: %u\n",
fw_req->firmware_id);
fw_req->timedout = true;
free_firmware(fw_download, fw_req);
}
static int exceeds_release_timeout(struct fw_request *fw_req)
{
struct fw_download *fw_download = fw_req->fw_download;
if (time_before(jiffies, fw_req->release_timeout_j))
return 0;
dev_err(fw_download->parent,
"Firmware download didn't finish in time, abort: %d\n",
fw_req->firmware_id);
fw_req->timedout = true;
free_firmware(fw_download, fw_req);
return -ETIMEDOUT;
}
/* This returns path of the firmware blob on the disk */
static struct fw_request *find_firmware(struct fw_download *fw_download,
const char *tag)
{
struct gb_interface *intf = fw_download->connection->bundle->intf;
struct fw_request *fw_req;
int ret, req_count;
fw_req = kzalloc(sizeof(*fw_req), GFP_KERNEL);
if (!fw_req)
return ERR_PTR(-ENOMEM);
/* Allocate ids from 1 to 255 (u8-max), 0 is an invalid id */
ret = ida_simple_get(&fw_download->id_map, 1, 256, GFP_KERNEL);
if (ret < 0) {
dev_err(fw_download->parent,
"failed to allocate firmware id (%d)\n", ret);
goto err_free_req;
}
fw_req->firmware_id = ret;
snprintf(fw_req->name, sizeof(fw_req->name),
FW_NAME_PREFIX "%08x_%08x_%08x_%08x_%s.tftf",
intf->ddbl1_manufacturer_id, intf->ddbl1_product_id,
intf->vendor_id, intf->product_id, tag);
dev_info(fw_download->parent, "Requested firmware package '%s'\n",
fw_req->name);
ret = request_firmware(&fw_req->fw, fw_req->name, fw_download->parent);
if (ret) {
dev_err(fw_download->parent,
"firmware request failed for %s (%d)\n", fw_req->name,
ret);
goto err_free_id;
}
fw_req->fw_download = fw_download;
kref_init(&fw_req->kref);
mutex_lock(&fw_download->mutex);
list_add(&fw_req->node, &fw_download->fw_requests);
mutex_unlock(&fw_download->mutex);
/* Timeout, in jiffies, within which firmware should get loaded */
req_count = DIV_ROUND_UP(fw_req->fw->size, MIN_FETCH_SIZE);
fw_req->release_timeout_j = jiffies + req_count * NEXT_REQ_TIMEOUT_J;
INIT_DELAYED_WORK(&fw_req->dwork, fw_request_timedout);
schedule_delayed_work(&fw_req->dwork, NEXT_REQ_TIMEOUT_J);
return fw_req;
err_free_id:
ida_simple_remove(&fw_download->id_map, fw_req->firmware_id);
err_free_req:
kfree(fw_req);
return ERR_PTR(ret);
}
static int fw_download_find_firmware(struct gb_operation *op)
{
struct gb_connection *connection = op->connection;
struct fw_download *fw_download = gb_connection_get_data(connection);
struct gb_fw_download_find_firmware_request *request;
struct gb_fw_download_find_firmware_response *response;
struct fw_request *fw_req;
const char *tag;
if (op->request->payload_size != sizeof(*request)) {
dev_err(fw_download->parent,
"illegal size of find firmware request (%zu != %zu)\n",
op->request->payload_size, sizeof(*request));
return -EINVAL;
}
request = op->request->payload;
tag = (const char *)(request->firmware_tag);
/* firmware_tag should be null-terminated */
if (strnlen(tag, GB_FIRMWARE_TAG_MAX_LEN) == GB_FIRMWARE_TAG_MAX_LEN) {
dev_err(fw_download->parent,
"firmware-tag is not null-terminated\n");
return -EINVAL;
}
fw_req = find_firmware(fw_download, request->firmware_tag);
if (IS_ERR(fw_req))
return PTR_ERR(fw_req);
if (!gb_operation_response_alloc(op, sizeof(*response), GFP_KERNEL)) {
dev_err(fw_download->parent, "error allocating response\n");
free_firmware(fw_download, fw_req);
return -ENOMEM;
}
response = op->response->payload;
response->firmware_id = fw_req->firmware_id;
response->size = cpu_to_le32(fw_req->fw->size);
dev_dbg(fw_download->parent,
"firmware size is %zu bytes\n", fw_req->fw->size);
return 0;
}
static int fw_download_fetch_firmware(struct gb_operation *op)
{
struct gb_connection *connection = op->connection;
struct fw_download *fw_download = gb_connection_get_data(connection);
struct gb_fw_download_fetch_firmware_request *request;
struct gb_fw_download_fetch_firmware_response *response;
struct fw_request *fw_req;
const struct firmware *fw;
unsigned int offset, size;
u8 firmware_id;
int ret = 0;
if (op->request->payload_size != sizeof(*request)) {
dev_err(fw_download->parent,
"Illegal size of fetch firmware request (%zu %zu)\n",
op->request->payload_size, sizeof(*request));
return -EINVAL;
}
request = op->request->payload;
offset = le32_to_cpu(request->offset);
size = le32_to_cpu(request->size);
firmware_id = request->firmware_id;
fw_req = get_fw_req(fw_download, firmware_id);
if (!fw_req) {
dev_err(fw_download->parent,
"firmware not available for id: %02u\n", firmware_id);
return -EINVAL;
}
/* Make sure work handler isn't running in parallel */
cancel_delayed_work_sync(&fw_req->dwork);
/* We timed-out before reaching here ? */
if (fw_req->disabled) {
ret = -ETIMEDOUT;
goto put_fw;
}
/*
* Firmware download must finish within a limited time interval. If it
* doesn't, then we might have a buggy Module on the other side. Abort
* download.
*/
ret = exceeds_release_timeout(fw_req);
if (ret)
goto put_fw;
fw = fw_req->fw;
if (offset >= fw->size || size > fw->size - offset) {
dev_err(fw_download->parent,
"bad fetch firmware request (offs = %u, size = %u)\n",
offset, size);
ret = -EINVAL;
goto put_fw;
}
if (!gb_operation_response_alloc(op, sizeof(*response) + size,
GFP_KERNEL)) {
dev_err(fw_download->parent,
"error allocating fetch firmware response\n");
ret = -ENOMEM;
goto put_fw;
}
response = op->response->payload;
memcpy(response->data, fw->data + offset, size);
dev_dbg(fw_download->parent,
"responding with firmware (offs = %u, size = %u)\n", offset,
size);
/* Refresh timeout */
schedule_delayed_work(&fw_req->dwork, NEXT_REQ_TIMEOUT_J);
put_fw:
put_fw_req(fw_req);
return ret;
}
static int fw_download_release_firmware(struct gb_operation *op)
{
struct gb_connection *connection = op->connection;
struct fw_download *fw_download = gb_connection_get_data(connection);
struct gb_fw_download_release_firmware_request *request;
struct fw_request *fw_req;
u8 firmware_id;
if (op->request->payload_size != sizeof(*request)) {
dev_err(fw_download->parent,
"Illegal size of release firmware request (%zu %zu)\n",
op->request->payload_size, sizeof(*request));
return -EINVAL;
}
request = op->request->payload;
firmware_id = request->firmware_id;
fw_req = get_fw_req(fw_download, firmware_id);
if (!fw_req) {
dev_err(fw_download->parent,
"firmware not available for id: %02u\n", firmware_id);
return -EINVAL;
}
cancel_delayed_work_sync(&fw_req->dwork);
free_firmware(fw_download, fw_req);
put_fw_req(fw_req);
dev_dbg(fw_download->parent, "release firmware\n");
return 0;
}
int gb_fw_download_request_handler(struct gb_operation *op)
{
u8 type = op->type;
switch (type) {
case GB_FW_DOWNLOAD_TYPE_FIND_FIRMWARE:
return fw_download_find_firmware(op);
case GB_FW_DOWNLOAD_TYPE_FETCH_FIRMWARE:
return fw_download_fetch_firmware(op);
case GB_FW_DOWNLOAD_TYPE_RELEASE_FIRMWARE:
return fw_download_release_firmware(op);
default:
dev_err(&op->connection->bundle->dev,
"unsupported request: %u\n", type);
return -EINVAL;
}
}
int gb_fw_download_connection_init(struct gb_connection *connection)
{
struct fw_download *fw_download;
int ret;
if (!connection)
return 0;
fw_download = kzalloc(sizeof(*fw_download), GFP_KERNEL);
if (!fw_download)
return -ENOMEM;
fw_download->parent = &connection->bundle->dev;
INIT_LIST_HEAD(&fw_download->fw_requests);
ida_init(&fw_download->id_map);
gb_connection_set_data(connection, fw_download);
fw_download->connection = connection;
mutex_init(&fw_download->mutex);
ret = gb_connection_enable(connection);
if (ret)
goto err_destroy_id_map;
return 0;
err_destroy_id_map:
ida_destroy(&fw_download->id_map);
kfree(fw_download);
return ret;
}
void gb_fw_download_connection_exit(struct gb_connection *connection)
{
struct fw_download *fw_download;
struct fw_request *fw_req, *tmp;
if (!connection)
return;
fw_download = gb_connection_get_data(connection);
gb_connection_disable(fw_download->connection);
/*
* Make sure we have a reference to the pending requests, before they
* are freed from the timeout handler.
*/
mutex_lock(&fw_download->mutex);
list_for_each_entry(fw_req, &fw_download->fw_requests, node)
kref_get(&fw_req->kref);
mutex_unlock(&fw_download->mutex);
/* Release pending firmware packages */
list_for_each_entry_safe(fw_req, tmp, &fw_download->fw_requests, node) {
cancel_delayed_work_sync(&fw_req->dwork);
free_firmware(fw_download, fw_req);
put_fw_req(fw_req);
}
ida_destroy(&fw_download->id_map);
kfree(fw_download);
}