// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2003-2018, Intel Corporation. All rights reserved.
* Intel Management Engine Interface (Intel MEI) Linux driver
*/
#include <linux/export.h>
#include <linux/kthread.h>
#include <linux/interrupt.h>
#include <linux/fs.h>
#include <linux/jiffies.h>
#include <linux/slab.h>
#include <linux/pm_runtime.h>
#include <linux/mei.h>
#include "mei_dev.h"
#include "hbm.h"
#include "client.h"
/**
* mei_irq_compl_handler - dispatch complete handlers
* for the completed callbacks
*
* @dev: mei device
* @cmpl_list: list of completed cbs
*/
void mei_irq_compl_handler(struct mei_device *dev, struct list_head *cmpl_list)
{
struct mei_cl_cb *cb, *next;
struct mei_cl *cl;
list_for_each_entry_safe(cb, next, cmpl_list, list) {
cl = cb->cl;
list_del_init(&cb->list);
dev_dbg(dev->dev, "completing call back.\n");
mei_cl_complete(cl, cb);
}
}
EXPORT_SYMBOL_GPL(mei_irq_compl_handler);
/**
* mei_cl_hbm_equal - check if hbm is addressed to the client
*
* @cl: host client
* @mei_hdr: header of mei client message
*
* Return: true if matches, false otherwise
*/
static inline int mei_cl_hbm_equal(struct mei_cl *cl,
struct mei_msg_hdr *mei_hdr)
{
return mei_cl_host_addr(cl) == mei_hdr->host_addr &&
mei_cl_me_id(cl) == mei_hdr->me_addr;
}
/**
* mei_irq_discard_msg - discard received message
*
* @dev: mei device
* @hdr: message header
* @discard_len: the length of the message to discard (excluding header)
*/
static void mei_irq_discard_msg(struct mei_device *dev, struct mei_msg_hdr *hdr,
size_t discard_len)
{
if (hdr->dma_ring) {
mei_dma_ring_read(dev, NULL,
hdr->extension[dev->rd_msg_hdr_count - 2]);
discard_len = 0;
}
/*
* no need to check for size as it is guaranteed
* that length fits into rd_msg_buf
*/
mei_read_slots(dev, dev->rd_msg_buf, discard_len);
dev_dbg(dev->dev, "discarding message " MEI_HDR_FMT "\n",
MEI_HDR_PRM(hdr));
}
/**
* mei_cl_irq_read_msg - process client message
*
* @cl: reading client
* @mei_hdr: header of mei client message
* @meta: extend meta header
* @cmpl_list: completion list
*
* Return: always 0
*/
static int mei_cl_irq_read_msg(struct mei_cl *cl,
struct mei_msg_hdr *mei_hdr,
struct mei_ext_meta_hdr *meta,
struct list_head *cmpl_list)
{
struct mei_device *dev = cl->dev;
struct mei_cl_cb *cb;
struct mei_ext_hdr_vtag *vtag_hdr = NULL;
struct mei_ext_hdr_gsc_f2h *gsc_f2h = NULL;
size_t buf_sz;
u32 length;
u32 ext_len;
length = mei_hdr->length;
ext_len = 0;
if (mei_hdr->extended) {
ext_len = sizeof(*meta) + mei_slots2data(meta->size);
length -= ext_len;
}
cb = list_first_entry_or_null(&cl->rd_pending, struct mei_cl_cb, list);
if (!cb) {
if (!mei_cl_is_fixed_address(cl)) {
cl_err(dev, cl, "pending read cb not found\n");
goto discard;
}
cb = mei_cl_alloc_cb(cl, mei_cl_mtu(cl), MEI_FOP_READ, cl->fp);
if (!cb)
goto discard;
list_add_tail(&cb->list, &cl->rd_pending);
}
if (mei_hdr->extended) {
struct mei_ext_hdr *ext = mei_ext_begin(meta);
do {
switch (ext->type) {
case MEI_EXT_HDR_VTAG:
vtag_hdr = (struct mei_ext_hdr_vtag *)ext;
break;
case MEI_EXT_HDR_GSC:
gsc_f2h = (struct mei_ext_hdr_gsc_f2h *)ext;
cb->ext_hdr = kzalloc(sizeof(*gsc_f2h), GFP_KERNEL);
if (!cb->ext_hdr) {
cb->status = -ENOMEM;
goto discard;
}
break;
case MEI_EXT_HDR_NONE:
fallthrough;
default:
cl_err(dev, cl, "unknown extended header\n");
cb->status = -EPROTO;
break;
}
ext = mei_ext_next(ext);
} while (!mei_ext_last(meta, ext));
if (!vtag_hdr && !gsc_f2h) {
cl_dbg(dev, cl, "no vtag or gsc found in extended header.\n");
cb->status = -EPROTO;
goto discard;
}
}
if (vtag_hdr) {
cl_dbg(dev, cl, "vtag: %d\n", vtag_hdr->vtag);
if (cb->vtag && cb->vtag != vtag_hdr->vtag) {
cl_err(dev, cl, "mismatched tag: %d != %d\n",
cb->vtag, vtag_hdr->vtag);
cb->status = -EPROTO;
goto discard;
}
cb->vtag = vtag_hdr->vtag;
}
if (gsc_f2h) {
u32 ext_hdr_len = mei_ext_hdr_len(&gsc_f2h->hdr);
if (!dev->hbm_f_gsc_supported) {
cl_err(dev, cl, "gsc extended header is not supported\n");
cb->status = -EPROTO;
goto discard;
}
if (length) {
cl_err(dev, cl, "no data allowed in cb with gsc\n");
cb->status = -EPROTO;
goto discard;
}
if (ext_hdr_len > sizeof(*gsc_f2h)) {
cl_err(dev, cl, "gsc extended header is too big %u\n", ext_hdr_len);
cb->status = -EPROTO;
goto discard;
}
memcpy(cb->ext_hdr, gsc_f2h, ext_hdr_len);
}
if (!mei_cl_is_connected(cl)) {
cl_dbg(dev, cl, "not connected\n");
cb->status = -ENODEV;
goto discard;
}
if (mei_hdr->dma_ring)
length = mei_hdr->extension[mei_data2slots(ext_len)];
buf_sz = length + cb->buf_idx;
/* catch for integer overflow */
if (buf_sz < cb->buf_idx) {
cl_err(dev, cl, "message is too big len %d idx %zu\n",
length, cb->buf_idx);
cb->status = -EMSGSIZE;
goto discard;
}
if (cb->buf.size < buf_sz) {
cl_dbg(dev, cl, "message overflow. size %zu len %d idx %zu\n",
cb->buf.size, length, cb->buf_idx);
cb->status = -EMSGSIZE;
goto discard;
}
if (mei_hdr->dma_ring) {
mei_dma_ring_read(dev, cb->buf.data + cb->buf_idx, length);
/* for DMA read 0 length to generate interrupt to the device */
mei_read_slots(dev, cb->buf.data + cb->buf_idx, 0);
} else {
mei_read_slots(dev, cb->buf.data + cb->buf_idx, length);
}
cb->buf_idx += length;
if (mei_hdr->msg_complete) {
cl_dbg(dev, cl, "completed read length = %zu\n", cb->buf_idx);
list_move_tail(&cb->list, cmpl_list);
} else {
pm_runtime_mark_last_busy(dev->dev);
pm_request_autosuspend(dev->dev);
}
return 0;
discard:
if (cb)
list_move_tail(&cb->list, cmpl_list);
mei_irq_discard_msg(dev, mei_hdr, length);
return 0;
}
/**
* mei_cl_irq_disconnect_rsp - send disconnection response message
*
* @cl: client
* @cb: callback block.
* @cmpl_list: complete list.
*
* Return: 0, OK; otherwise, error.
*/
static int mei_cl_irq_disconnect_rsp(struct mei_cl *cl, struct mei_cl_cb *cb,
struct list_head *cmpl_list)
{
struct mei_device *dev = cl->dev;
u32 msg_slots;
int slots;
int ret;
msg_slots = mei_hbm2slots(sizeof(struct hbm_client_connect_response));
slots = mei_hbuf_empty_slots(dev);
if (slots < 0)
return -EOVERFLOW;
if ((u32)slots < msg_slots)
return -EMSGSIZE;
ret = mei_hbm_cl_disconnect_rsp(dev, cl);
list_move_tail(&cb->list, cmpl_list);
return ret;
}
/**
* mei_cl_irq_read - processes client read related operation from the
* interrupt thread context - request for flow control credits
*
* @cl: client
* @cb: callback block.
* @cmpl_list: complete list.
*
* Return: 0, OK; otherwise, error.
*/
static int mei_cl_irq_read(struct mei_cl *cl, struct mei_cl_cb *cb,
struct list_head *cmpl_list)
{
struct mei_device *dev = cl->dev;
u32 msg_slots;
int slots;
int ret;
if (!list_empty(&cl->rd_pending))
return 0;
msg_slots = mei_hbm2slots(sizeof(struct hbm_flow_control));
slots = mei_hbuf_empty_slots(dev);
if (slots < 0)
return -EOVERFLOW;
if ((u32)slots < msg_slots)
return -EMSGSIZE;
ret = mei_hbm_cl_flow_control_req(dev, cl);
if (ret) {
cl->status = ret;
cb->buf_idx = 0;
list_move_tail(&cb->list, cmpl_list);
return ret;
}
pm_runtime_mark_last_busy(dev->dev);
pm_request_autosuspend(dev->dev);
list_move_tail(&cb->list, &cl->rd_pending);
return 0;
}
static inline bool hdr_is_hbm(struct mei_msg_hdr *mei_hdr)
{
return mei_hdr->host_addr == 0 && mei_hdr->me_addr == 0;
}
static inline bool hdr_is_fixed(struct mei_msg_hdr *mei_hdr)
{
return mei_hdr->host_addr == 0 && mei_hdr->me_addr != 0;
}
static inline int hdr_is_valid(u32 msg_hdr)
{
struct mei_msg_hdr *mei_hdr;
u32 expected_len = 0;
mei_hdr = (struct mei_msg_hdr *)&msg_hdr;
if (!msg_hdr || mei_hdr->reserved)
return -EBADMSG;
if (mei_hdr->dma_ring)
expected_len += MEI_SLOT_SIZE;
if (mei_hdr->extended)
expected_len += MEI_SLOT_SIZE;
if (mei_hdr->length < expected_len)
return -EBADMSG;
return 0;
}
/**
* mei_irq_read_handler - bottom half read routine after ISR to
* handle the read processing.
*
* @dev: the device structure
* @cmpl_list: An instance of our list structure
* @slots: slots to read.
*
* Return: 0 on success, <0 on failure.
*/
int mei_irq_read_handler(struct mei_device *dev,
struct list_head *cmpl_list, s32 *slots)
{
struct mei_msg_hdr *mei_hdr;
struct mei_ext_meta_hdr *meta_hdr = NULL;
struct mei_cl *cl;
int ret;
u32 hdr_size_left;
u32 hdr_size_ext;
int i;
int ext_hdr_end;
if (!dev->rd_msg_hdr[0]) {
dev->rd_msg_hdr[0] = mei_read_hdr(dev);
dev->rd_msg_hdr_count = 1;
(*slots)--;
dev_dbg(dev->dev, "slots =%08x.\n", *slots);
ret = hdr_is_valid(dev->rd_msg_hdr[0]);
if (ret) {
dev_err(dev->dev, "corrupted message header 0x%08X\n",
dev->rd_msg_hdr[0]);
goto end;
}
}
mei_hdr = (struct mei_msg_hdr *)dev->rd_msg_hdr;
dev_dbg(dev->dev, MEI_HDR_FMT, MEI_HDR_PRM(mei_hdr));
if (mei_slots2data(*slots) < mei_hdr->length) {
dev_err(dev->dev, "less data available than length=%08x.\n",
*slots);
/* we can't read the message */
ret = -ENODATA;
goto end;
}
ext_hdr_end = 1;
hdr_size_left = mei_hdr->length;
if (mei_hdr->extended) {
if (!dev->rd_msg_hdr[1]) {
dev->rd_msg_hdr[1] = mei_read_hdr(dev);
dev->rd_msg_hdr_count++;
(*slots)--;
dev_dbg(dev->dev, "extended header is %08x\n", dev->rd_msg_hdr[1]);
}
meta_hdr = ((struct mei_ext_meta_hdr *)&dev->rd_msg_hdr[1]);
if (check_add_overflow((u32)sizeof(*meta_hdr),
mei_slots2data(meta_hdr->size),
&hdr_size_ext)) {
dev_err(dev->dev, "extended message size too big %d\n",
meta_hdr->size);
return -EBADMSG;
}
if (hdr_size_left < hdr_size_ext) {
dev_err(dev->dev, "corrupted message header len %d\n",
mei_hdr->length);
return -EBADMSG;
}
hdr_size_left -= hdr_size_ext;
ext_hdr_end = meta_hdr->size + 2;
for (i = dev->rd_msg_hdr_count; i < ext_hdr_end; i++) {
dev->rd_msg_hdr[i] = mei_read_hdr(dev);
dev_dbg(dev->dev, "extended header %d is %08x\n", i,
dev->rd_msg_hdr[i]);
dev->rd_msg_hdr_count++;
(*slots)--;
}
}
if (mei_hdr->dma_ring) {
if (hdr_size_left != sizeof(dev->rd_msg_hdr[ext_hdr_end])) {
dev_err(dev->dev, "corrupted message header len %d\n",
mei_hdr->length);
return -EBADMSG;
}
dev->rd_msg_hdr[ext_hdr_end] = mei_read_hdr(dev);
dev->rd_msg_hdr_count++;
(*slots)--;
mei_hdr->length -= sizeof(dev->rd_msg_hdr[ext_hdr_end]);
}
/* HBM message */
if (hdr_is_hbm(mei_hdr)) {
ret = mei_hbm_dispatch(dev, mei_hdr);
if (ret) {
dev_dbg(dev->dev, "mei_hbm_dispatch failed ret = %d\n",
ret);
goto end;
}
goto reset_slots;
}
/* find recipient cl */
list_for_each_entry(cl, &dev->file_list, link) {
if (mei_cl_hbm_equal(cl, mei_hdr)) {
cl_dbg(dev, cl, "got a message\n");
ret = mei_cl_irq_read_msg(cl, mei_hdr, meta_hdr, cmpl_list);
goto reset_slots;
}
}
/* if no recipient cl was found we assume corrupted header */
/* A message for not connected fixed address clients
* should be silently discarded
* On power down client may be force cleaned,
* silently discard such messages
*/
if (hdr_is_fixed(mei_hdr) ||
dev->dev_state == MEI_DEV_POWER_DOWN) {
mei_irq_discard_msg(dev, mei_hdr, mei_hdr->length);
ret = 0;
goto reset_slots;
}
dev_err(dev->dev, "no destination client found 0x%08X\n", dev->rd_msg_hdr[0]);
ret = -EBADMSG;
goto end;
reset_slots:
/* reset the number of slots and header */
memset(dev->rd_msg_hdr, 0, sizeof(dev->rd_msg_hdr));
dev->rd_msg_hdr_count = 0;
*slots = mei_count_full_read_slots(dev);
if (*slots == -EOVERFLOW) {
/* overflow - reset */
dev_err(dev->dev, "resetting due to slots overflow.\n");
/* set the event since message has been read */
ret = -ERANGE;
goto end;
}
end:
return ret;
}
EXPORT_SYMBOL_GPL(mei_irq_read_handler);
/**
* mei_irq_write_handler - dispatch write requests
* after irq received
*
* @dev: the device structure
* @cmpl_list: An instance of our list structure
*
* Return: 0 on success, <0 on failure.
*/
int mei_irq_write_handler(struct mei_device *dev, struct list_head *cmpl_list)
{
struct mei_cl *cl;
struct mei_cl_cb *cb, *next;
s32 slots;
int ret;
if (!mei_hbuf_acquire(dev))
return 0;
slots = mei_hbuf_empty_slots(dev);
if (slots < 0)
return -EOVERFLOW;
if (slots == 0)
return -EMSGSIZE;
/* complete all waiting for write CB */
dev_dbg(dev->dev, "complete all waiting for write cb.\n");
list_for_each_entry_safe(cb, next, &dev->write_waiting_list, list) {
cl = cb->cl;
cl->status = 0;
cl_dbg(dev, cl, "MEI WRITE COMPLETE\n");
cl->writing_state = MEI_WRITE_COMPLETE;
list_move_tail(&cb->list, cmpl_list);
}
/* complete control write list CB */
dev_dbg(dev->dev, "complete control write list cb.\n");
list_for_each_entry_safe(cb, next, &dev->ctrl_wr_list, list) {
cl = cb->cl;
switch (cb->fop_type) {
case MEI_FOP_DISCONNECT:
/* send disconnect message */
ret = mei_cl_irq_disconnect(cl, cb, cmpl_list);
if (ret)
return ret;
break;
case MEI_FOP_READ:
/* send flow control message */
ret = mei_cl_irq_read(cl, cb, cmpl_list);
if (ret)
return ret;
break;
case MEI_FOP_CONNECT:
/* connect message */
ret = mei_cl_irq_connect(cl, cb, cmpl_list);
if (ret)
return ret;
break;
case MEI_FOP_DISCONNECT_RSP:
/* send disconnect resp */
ret = mei_cl_irq_disconnect_rsp(cl, cb, cmpl_list);
if (ret)
return ret;
break;
case MEI_FOP_NOTIFY_START:
case MEI_FOP_NOTIFY_STOP:
ret = mei_cl_irq_notify(cl, cb, cmpl_list);
if (ret)
return ret;
break;
case MEI_FOP_DMA_MAP:
ret = mei_cl_irq_dma_map(cl, cb, cmpl_list);
if (ret)
return ret;
break;
case MEI_FOP_DMA_UNMAP:
ret = mei_cl_irq_dma_unmap(cl, cb, cmpl_list);
if (ret)
return ret;
break;
default:
BUG();
}
}
/* complete write list CB */
dev_dbg(dev->dev, "complete write list cb.\n");
list_for_each_entry_safe(cb, next, &dev->write_list, list) {
cl = cb->cl;
ret = mei_cl_irq_write(cl, cb, cmpl_list);
if (ret)
return ret;
}
return 0;
}
EXPORT_SYMBOL_GPL(mei_irq_write_handler);
/**
* mei_connect_timeout - connect/disconnect timeouts
*
* @cl: host client
*/
static void mei_connect_timeout(struct mei_cl *cl)
{
struct mei_device *dev = cl->dev;
if (cl->state == MEI_FILE_CONNECTING) {
if (dev->hbm_f_dot_supported) {
cl->state = MEI_FILE_DISCONNECT_REQUIRED;
wake_up(&cl->wait);
return;
}
}
mei_reset(dev);
}
#define MEI_STALL_TIMER_FREQ (2 * HZ)
/**
* mei_schedule_stall_timer - re-arm stall_timer work
*
* @dev: the device structure
*
* Schedule stall timer
*/
void mei_schedule_stall_timer(struct mei_device *dev)
{
schedule_delayed_work(&dev->timer_work, MEI_STALL_TIMER_FREQ);
}
/**
* mei_timer - timer function.
*
* @work: pointer to the work_struct structure
*
*/
void mei_timer(struct work_struct *work)
{
struct mei_cl *cl;
struct mei_device *dev = container_of(work,
struct mei_device, timer_work.work);
bool reschedule_timer = false;
mutex_lock(&dev->device_lock);
/* Catch interrupt stalls during HBM init handshake */
if (dev->dev_state == MEI_DEV_INIT_CLIENTS &&
dev->hbm_state != MEI_HBM_IDLE) {
if (dev->init_clients_timer) {
if (--dev->init_clients_timer == 0) {
dev_err(dev->dev, "timer: init clients timeout hbm_state = %d.\n",
dev->hbm_state);
mei_reset(dev);
goto out;
}
reschedule_timer = true;
}
}
if (dev->dev_state != MEI_DEV_ENABLED)
goto out;
/*** connect/disconnect timeouts ***/
list_for_each_entry(cl, &dev->file_list, link) {
if (cl->timer_count) {
if (--cl->timer_count == 0) {
dev_err(dev->dev, "timer: connect/disconnect timeout.\n");
mei_connect_timeout(cl);
goto out;
}
reschedule_timer = true;
}
}
out:
if (dev->dev_state != MEI_DEV_DISABLED && reschedule_timer)
mei_schedule_stall_timer(dev);
mutex_unlock(&dev->device_lock);
}
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