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|
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2018-2020, The Linux Foundation. All rights reserved.
*
*/
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/dma-direction.h>
#include <linux/dma-mapping.h>
#include <linux/interrupt.h>
#include <linux/list.h>
#include <linux/mhi.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include "internal.h"
int __must_check mhi_read_reg(struct mhi_controller *mhi_cntrl,
void __iomem *base, u32 offset, u32 *out)
{
return mhi_cntrl->read_reg(mhi_cntrl, base + offset, out);
}
int __must_check mhi_read_reg_field(struct mhi_controller *mhi_cntrl,
void __iomem *base, u32 offset,
u32 mask, u32 *out)
{
u32 tmp;
int ret;
ret = mhi_read_reg(mhi_cntrl, base, offset, &tmp);
if (ret)
return ret;
*out = (tmp & mask) >> __ffs(mask);
return 0;
}
int __must_check mhi_poll_reg_field(struct mhi_controller *mhi_cntrl,
void __iomem *base, u32 offset,
u32 mask, u32 val, u32 delayus,
u32 timeout_ms)
{
int ret;
u32 out, retry = (timeout_ms * 1000) / delayus;
while (retry--) {
ret = mhi_read_reg_field(mhi_cntrl, base, offset, mask, &out);
if (ret)
return ret;
if (out == val)
return 0;
fsleep(delayus);
}
return -ETIMEDOUT;
}
void mhi_write_reg(struct mhi_controller *mhi_cntrl, void __iomem *base,
u32 offset, u32 val)
{
mhi_cntrl->write_reg(mhi_cntrl, base + offset, val);
}
int __must_check mhi_write_reg_field(struct mhi_controller *mhi_cntrl,
void __iomem *base, u32 offset, u32 mask,
u32 val)
{
int ret;
u32 tmp;
ret = mhi_read_reg(mhi_cntrl, base, offset, &tmp);
if (ret)
return ret;
tmp &= ~mask;
tmp |= (val << __ffs(mask));
mhi_write_reg(mhi_cntrl, base, offset, tmp);
return 0;
}
void mhi_write_db(struct mhi_controller *mhi_cntrl, void __iomem *db_addr,
dma_addr_t db_val)
{
mhi_write_reg(mhi_cntrl, db_addr, 4, upper_32_bits(db_val));
mhi_write_reg(mhi_cntrl, db_addr, 0, lower_32_bits(db_val));
}
void mhi_db_brstmode(struct mhi_controller *mhi_cntrl,
struct db_cfg *db_cfg,
void __iomem *db_addr,
dma_addr_t db_val)
{
if (db_cfg->db_mode) {
db_cfg->db_val = db_val;
mhi_write_db(mhi_cntrl, db_addr, db_val);
db_cfg->db_mode = 0;
}
}
void mhi_db_brstmode_disable(struct mhi_controller *mhi_cntrl,
struct db_cfg *db_cfg,
void __iomem *db_addr,
dma_addr_t db_val)
{
db_cfg->db_val = db_val;
mhi_write_db(mhi_cntrl, db_addr, db_val);
}
void mhi_ring_er_db(struct mhi_event *mhi_event)
{
struct mhi_ring *ring = &mhi_event->ring;
mhi_event->db_cfg.process_db(mhi_event->mhi_cntrl, &mhi_event->db_cfg,
ring->db_addr, le64_to_cpu(*ring->ctxt_wp));
}
void mhi_ring_cmd_db(struct mhi_controller *mhi_cntrl, struct mhi_cmd *mhi_cmd)
{
dma_addr_t db;
struct mhi_ring *ring = &mhi_cmd->ring;
db = ring->iommu_base + (ring->wp - ring->base);
*ring->ctxt_wp = cpu_to_le64(db);
mhi_write_db(mhi_cntrl, ring->db_addr, db);
}
void mhi_ring_chan_db(struct mhi_controller *mhi_cntrl,
struct mhi_chan *mhi_chan)
{
struct mhi_ring *ring = &mhi_chan->tre_ring;
dma_addr_t db;
db = ring->iommu_base + (ring->wp - ring->base);
/*
* Writes to the new ring element must be visible to the hardware
* before letting h/w know there is new element to fetch.
*/
dma_wmb();
*ring->ctxt_wp = cpu_to_le64(db);
mhi_chan->db_cfg.process_db(mhi_cntrl, &mhi_chan->db_cfg,
ring->db_addr, db);
}
enum mhi_ee_type mhi_get_exec_env(struct mhi_controller *mhi_cntrl)
{
u32 exec;
int ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->bhi, BHI_EXECENV, &exec);
return (ret) ? MHI_EE_MAX : exec;
}
EXPORT_SYMBOL_GPL(mhi_get_exec_env);
enum mhi_state mhi_get_mhi_state(struct mhi_controller *mhi_cntrl)
{
u32 state;
int ret = mhi_read_reg_field(mhi_cntrl, mhi_cntrl->regs, MHISTATUS,
MHISTATUS_MHISTATE_MASK, &state);
return ret ? MHI_STATE_MAX : state;
}
EXPORT_SYMBOL_GPL(mhi_get_mhi_state);
void mhi_soc_reset(struct mhi_controller *mhi_cntrl)
{
if (mhi_cntrl->reset) {
mhi_cntrl->reset(mhi_cntrl);
return;
}
/* Generic MHI SoC reset */
mhi_write_reg(mhi_cntrl, mhi_cntrl->regs, MHI_SOC_RESET_REQ_OFFSET,
MHI_SOC_RESET_REQ);
}
EXPORT_SYMBOL_GPL(mhi_soc_reset);
int mhi_map_single_no_bb(struct mhi_controller *mhi_cntrl,
struct mhi_buf_info *buf_info)
{
buf_info->p_addr = dma_map_single(mhi_cntrl->cntrl_dev,
buf_info->v_addr, buf_info->len,
buf_info->dir);
if (dma_mapping_error(mhi_cntrl->cntrl_dev, buf_info->p_addr))
return -ENOMEM;
return 0;
}
int mhi_map_single_use_bb(struct mhi_controller *mhi_cntrl,
struct mhi_buf_info *buf_info)
{
void *buf = dma_alloc_coherent(mhi_cntrl->cntrl_dev, buf_info->len,
&buf_info->p_addr, GFP_ATOMIC);
if (!buf)
return -ENOMEM;
if (buf_info->dir == DMA_TO_DEVICE)
memcpy(buf, buf_info->v_addr, buf_info->len);
buf_info->bb_addr = buf;
return 0;
}
void mhi_unmap_single_no_bb(struct mhi_controller *mhi_cntrl,
struct mhi_buf_info *buf_info)
{
dma_unmap_single(mhi_cntrl->cntrl_dev, buf_info->p_addr, buf_info->len,
buf_info->dir);
}
void mhi_unmap_single_use_bb(struct mhi_controller *mhi_cntrl,
struct mhi_buf_info *buf_info)
{
if (buf_info->dir == DMA_FROM_DEVICE)
memcpy(buf_info->v_addr, buf_info->bb_addr, buf_info->len);
dma_free_coherent(mhi_cntrl->cntrl_dev, buf_info->len,
buf_info->bb_addr, buf_info->p_addr);
}
static int get_nr_avail_ring_elements(struct mhi_controller *mhi_cntrl,
struct mhi_ring *ring)
{
int nr_el;
if (ring->wp < ring->rp) {
nr_el = ((ring->rp - ring->wp) / ring->el_size) - 1;
} else {
nr_el = (ring->rp - ring->base) / ring->el_size;
nr_el += ((ring->base + ring->len - ring->wp) /
ring->el_size) - 1;
}
return nr_el;
}
static void *mhi_to_virtual(struct mhi_ring *ring, dma_addr_t addr)
{
return (addr - ring->iommu_base) + ring->base;
}
static void mhi_add_ring_element(struct mhi_controller *mhi_cntrl,
struct mhi_ring *ring)
{
ring->wp += ring->el_size;
if (ring->wp >= (ring->base + ring->len))
ring->wp = ring->base;
/* smp update */
smp_wmb();
}
static void mhi_del_ring_element(struct mhi_controller *mhi_cntrl,
struct mhi_ring *ring)
{
ring->rp += ring->el_size;
if (ring->rp >= (ring->base + ring->len))
ring->rp = ring->base;
/* smp update */
smp_wmb();
}
static bool is_valid_ring_ptr(struct mhi_ring *ring, dma_addr_t addr)
{
return addr >= ring->iommu_base && addr < ring->iommu_base + ring->len &&
!(addr & (sizeof(struct mhi_ring_element) - 1));
}
int mhi_destroy_device(struct device *dev, void *data)
{
struct mhi_chan *ul_chan, *dl_chan;
struct mhi_device *mhi_dev;
struct mhi_controller *mhi_cntrl;
enum mhi_ee_type ee = MHI_EE_MAX;
if (dev->bus != &mhi_bus_type)
return 0;
mhi_dev = to_mhi_device(dev);
mhi_cntrl = mhi_dev->mhi_cntrl;
/* Only destroy virtual devices thats attached to bus */
if (mhi_dev->dev_type == MHI_DEVICE_CONTROLLER)
return 0;
ul_chan = mhi_dev->ul_chan;
dl_chan = mhi_dev->dl_chan;
/*
* If execution environment is specified, remove only those devices that
* started in them based on ee_mask for the channels as we move on to a
* different execution environment
*/
if (data)
ee = *(enum mhi_ee_type *)data;
/*
* For the suspend and resume case, this function will get called
* without mhi_unregister_controller(). Hence, we need to drop the
* references to mhi_dev created for ul and dl channels. We can
* be sure that there will be no instances of mhi_dev left after
* this.
*/
if (ul_chan) {
if (ee != MHI_EE_MAX && !(ul_chan->ee_mask & BIT(ee)))
return 0;
put_device(&ul_chan->mhi_dev->dev);
}
if (dl_chan) {
if (ee != MHI_EE_MAX && !(dl_chan->ee_mask & BIT(ee)))
return 0;
put_device(&dl_chan->mhi_dev->dev);
}
dev_dbg(&mhi_cntrl->mhi_dev->dev, "destroy device for chan:%s\n",
mhi_dev->name);
/* Notify the client and remove the device from MHI bus */
device_del(dev);
put_device(dev);
return 0;
}
int mhi_get_free_desc_count(struct mhi_device *mhi_dev,
enum dma_data_direction dir)
{
struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
struct mhi_chan *mhi_chan = (dir == DMA_TO_DEVICE) ?
mhi_dev->ul_chan : mhi_dev->dl_chan;
struct mhi_ring *tre_ring = &mhi_chan->tre_ring;
return get_nr_avail_ring_elements(mhi_cntrl, tre_ring);
}
EXPORT_SYMBOL_GPL(mhi_get_free_desc_count);
void mhi_notify(struct mhi_device *mhi_dev, enum mhi_callback cb_reason)
{
struct mhi_driver *mhi_drv;
if (!mhi_dev->dev.driver)
return;
mhi_drv = to_mhi_driver(mhi_dev->dev.driver);
if (mhi_drv->status_cb)
mhi_drv->status_cb(mhi_dev, cb_reason);
}
EXPORT_SYMBOL_GPL(mhi_notify);
/* Bind MHI channels to MHI devices */
void mhi_create_devices(struct mhi_controller *mhi_cntrl)
{
struct mhi_chan *mhi_chan;
struct mhi_device *mhi_dev;
struct device *dev = &mhi_cntrl->mhi_dev->dev;
int i, ret;
mhi_chan = mhi_cntrl->mhi_chan;
for (i = 0; i < mhi_cntrl->max_chan; i++, mhi_chan++) {
if (!mhi_chan->configured || mhi_chan->mhi_dev ||
!(mhi_chan->ee_mask & BIT(mhi_cntrl->ee)))
continue;
mhi_dev = mhi_alloc_device(mhi_cntrl);
if (IS_ERR(mhi_dev))
return;
mhi_dev->dev_type = MHI_DEVICE_XFER;
switch (mhi_chan->dir) {
case DMA_TO_DEVICE:
mhi_dev->ul_chan = mhi_chan;
mhi_dev->ul_chan_id = mhi_chan->chan;
break;
case DMA_FROM_DEVICE:
/* We use dl_chan as offload channels */
mhi_dev->dl_chan = mhi_chan;
mhi_dev->dl_chan_id = mhi_chan->chan;
break;
default:
dev_err(dev, "Direction not supported\n");
put_device(&mhi_dev->dev);
return;
}
get_device(&mhi_dev->dev);
mhi_chan->mhi_dev = mhi_dev;
/* Check next channel if it matches */
if ((i + 1) < mhi_cntrl->max_chan && mhi_chan[1].configured) {
if (!strcmp(mhi_chan[1].name, mhi_chan->name)) {
i++;
mhi_chan++;
if (mhi_chan->dir == DMA_TO_DEVICE) {
mhi_dev->ul_chan = mhi_chan;
mhi_dev->ul_chan_id = mhi_chan->chan;
} else {
mhi_dev->dl_chan = mhi_chan;
mhi_dev->dl_chan_id = mhi_chan->chan;
}
get_device(&mhi_dev->dev);
mhi_chan->mhi_dev = mhi_dev;
}
}
/* Channel name is same for both UL and DL */
mhi_dev->name = mhi_chan->name;
dev_set_name(&mhi_dev->dev, "%s_%s",
dev_name(&mhi_cntrl->mhi_dev->dev),
mhi_dev->name);
/* Init wakeup source if available */
if (mhi_dev->dl_chan && mhi_dev->dl_chan->wake_capable)
device_init_wakeup(&mhi_dev->dev, true);
ret = device_add(&mhi_dev->dev);
if (ret)
put_device(&mhi_dev->dev);
}
}
irqreturn_t mhi_irq_handler(int irq_number, void *dev)
{
struct mhi_event *mhi_event = dev;
struct mhi_controller *mhi_cntrl = mhi_event->mhi_cntrl;
struct mhi_event_ctxt *er_ctxt;
struct mhi_ring *ev_ring = &mhi_event->ring;
dma_addr_t ptr;
void *dev_rp;
/*
* If CONFIG_DEBUG_SHIRQ is set, the IRQ handler will get invoked during __free_irq()
* and by that time mhi_ctxt() would've freed. So check for the existence of mhi_ctxt
* before handling the IRQs.
*/
if (!mhi_cntrl->mhi_ctxt) {
dev_dbg(&mhi_cntrl->mhi_dev->dev,
"mhi_ctxt has been freed\n");
return IRQ_HANDLED;
}
er_ctxt = &mhi_cntrl->mhi_ctxt->er_ctxt[mhi_event->er_index];
ptr = le64_to_cpu(er_ctxt->rp);
if (!is_valid_ring_ptr(ev_ring, ptr)) {
dev_err(&mhi_cntrl->mhi_dev->dev,
"Event ring rp points outside of the event ring\n");
return IRQ_HANDLED;
}
dev_rp = mhi_to_virtual(ev_ring, ptr);
/* Only proceed if event ring has pending events */
if (ev_ring->rp == dev_rp)
return IRQ_HANDLED;
/* For client managed event ring, notify pending data */
if (mhi_event->cl_manage) {
struct mhi_chan *mhi_chan = mhi_event->mhi_chan;
struct mhi_device *mhi_dev = mhi_chan->mhi_dev;
if (mhi_dev)
mhi_notify(mhi_dev, MHI_CB_PENDING_DATA);
} else {
tasklet_schedule(&mhi_event->task);
}
return IRQ_HANDLED;
}
irqreturn_t mhi_intvec_threaded_handler(int irq_number, void *priv)
{
struct mhi_controller *mhi_cntrl = priv;
struct device *dev = &mhi_cntrl->mhi_dev->dev;
enum mhi_state state;
enum mhi_pm_state pm_state = 0;
enum mhi_ee_type ee;
write_lock_irq(&mhi_cntrl->pm_lock);
if (!MHI_REG_ACCESS_VALID(mhi_cntrl->pm_state)) {
write_unlock_irq(&mhi_cntrl->pm_lock);
goto exit_intvec;
}
state = mhi_get_mhi_state(mhi_cntrl);
ee = mhi_get_exec_env(mhi_cntrl);
dev_dbg(dev, "local ee: %s state: %s device ee: %s state: %s\n",
TO_MHI_EXEC_STR(mhi_cntrl->ee),
mhi_state_str(mhi_cntrl->dev_state),
TO_MHI_EXEC_STR(ee), mhi_state_str(state));
if (state == MHI_STATE_SYS_ERR) {
dev_dbg(dev, "System error detected\n");
pm_state = mhi_tryset_pm_state(mhi_cntrl,
MHI_PM_SYS_ERR_DETECT);
}
write_unlock_irq(&mhi_cntrl->pm_lock);
if (pm_state != MHI_PM_SYS_ERR_DETECT)
goto exit_intvec;
switch (ee) {
case MHI_EE_RDDM:
/* proceed if power down is not already in progress */
if (mhi_cntrl->rddm_image && mhi_is_active(mhi_cntrl)) {
mhi_cntrl->status_cb(mhi_cntrl, MHI_CB_EE_RDDM);
mhi_cntrl->ee = ee;
wake_up_all(&mhi_cntrl->state_event);
}
break;
case MHI_EE_PBL:
case MHI_EE_EDL:
case MHI_EE_PTHRU:
mhi_cntrl->status_cb(mhi_cntrl, MHI_CB_FATAL_ERROR);
mhi_cntrl->ee = ee;
wake_up_all(&mhi_cntrl->state_event);
mhi_pm_sys_err_handler(mhi_cntrl);
break;
default:
wake_up_all(&mhi_cntrl->state_event);
mhi_pm_sys_err_handler(mhi_cntrl);
break;
}
exit_intvec:
return IRQ_HANDLED;
}
irqreturn_t mhi_intvec_handler(int irq_number, void *dev)
{
struct mhi_controller *mhi_cntrl = dev;
/* Wake up events waiting for state change */
wake_up_all(&mhi_cntrl->state_event);
return IRQ_WAKE_THREAD;
}
static void mhi_recycle_ev_ring_element(struct mhi_controller *mhi_cntrl,
struct mhi_ring *ring)
{
/* Update the WP */
ring->wp += ring->el_size;
if (ring->wp >= (ring->base + ring->len))
ring->wp = ring->base;
*ring->ctxt_wp = cpu_to_le64(ring->iommu_base + (ring->wp - ring->base));
/* Update the RP */
ring->rp += ring->el_size;
if (ring->rp >= (ring->base + ring->len))
ring->rp = ring->base;
/* Update to all cores */
smp_wmb();
}
static int parse_xfer_event(struct mhi_controller *mhi_cntrl,
struct mhi_ring_element *event,
struct mhi_chan *mhi_chan)
{
struct mhi_ring *buf_ring, *tre_ring;
struct device *dev = &mhi_cntrl->mhi_dev->dev;
struct mhi_result result;
unsigned long flags = 0;
u32 ev_code;
ev_code = MHI_TRE_GET_EV_CODE(event);
buf_ring = &mhi_chan->buf_ring;
tre_ring = &mhi_chan->tre_ring;
result.transaction_status = (ev_code == MHI_EV_CC_OVERFLOW) ?
-EOVERFLOW : 0;
/*
* If it's a DB Event then we need to grab the lock
* with preemption disabled and as a write because we
* have to update db register and there are chances that
* another thread could be doing the same.
*/
if (ev_code >= MHI_EV_CC_OOB)
write_lock_irqsave(&mhi_chan->lock, flags);
else
read_lock_bh(&mhi_chan->lock);
if (mhi_chan->ch_state != MHI_CH_STATE_ENABLED)
goto end_process_tx_event;
switch (ev_code) {
case MHI_EV_CC_OVERFLOW:
case MHI_EV_CC_EOB:
case MHI_EV_CC_EOT:
{
dma_addr_t ptr = MHI_TRE_GET_EV_PTR(event);
struct mhi_ring_element *local_rp, *ev_tre;
void *dev_rp;
struct mhi_buf_info *buf_info;
u16 xfer_len;
if (!is_valid_ring_ptr(tre_ring, ptr)) {
dev_err(&mhi_cntrl->mhi_dev->dev,
"Event element points outside of the tre ring\n");
break;
}
/* Get the TRB this event points to */
ev_tre = mhi_to_virtual(tre_ring, ptr);
dev_rp = ev_tre + 1;
if (dev_rp >= (tre_ring->base + tre_ring->len))
dev_rp = tre_ring->base;
result.dir = mhi_chan->dir;
local_rp = tre_ring->rp;
while (local_rp != dev_rp) {
buf_info = buf_ring->rp;
/* If it's the last TRE, get length from the event */
if (local_rp == ev_tre)
xfer_len = MHI_TRE_GET_EV_LEN(event);
else
xfer_len = buf_info->len;
/* Unmap if it's not pre-mapped by client */
if (likely(!buf_info->pre_mapped))
mhi_cntrl->unmap_single(mhi_cntrl, buf_info);
result.buf_addr = buf_info->cb_buf;
/* truncate to buf len if xfer_len is larger */
result.bytes_xferd =
min_t(u16, xfer_len, buf_info->len);
mhi_del_ring_element(mhi_cntrl, buf_ring);
mhi_del_ring_element(mhi_cntrl, tre_ring);
local_rp = tre_ring->rp;
/* notify client */
mhi_chan->xfer_cb(mhi_chan->mhi_dev, &result);
if (mhi_chan->dir == DMA_TO_DEVICE) {
atomic_dec(&mhi_cntrl->pending_pkts);
/* Release the reference got from mhi_queue() */
mhi_cntrl->runtime_put(mhi_cntrl);
}
/*
* Recycle the buffer if buffer is pre-allocated,
* if there is an error, not much we can do apart
* from dropping the packet
*/
if (mhi_chan->pre_alloc) {
if (mhi_queue_buf(mhi_chan->mhi_dev,
mhi_chan->dir,
buf_info->cb_buf,
buf_info->len, MHI_EOT)) {
dev_err(dev,
"Error recycling buffer for chan:%d\n",
mhi_chan->chan);
kfree(buf_info->cb_buf);
}
}
}
break;
} /* CC_EOT */
case MHI_EV_CC_OOB:
case MHI_EV_CC_DB_MODE:
{
unsigned long pm_lock_flags;
mhi_chan->db_cfg.db_mode = 1;
read_lock_irqsave(&mhi_cntrl->pm_lock, pm_lock_flags);
if (tre_ring->wp != tre_ring->rp &&
MHI_DB_ACCESS_VALID(mhi_cntrl)) {
mhi_ring_chan_db(mhi_cntrl, mhi_chan);
}
read_unlock_irqrestore(&mhi_cntrl->pm_lock, pm_lock_flags);
break;
}
case MHI_EV_CC_BAD_TRE:
default:
dev_err(dev, "Unknown event 0x%x\n", ev_code);
break;
} /* switch(MHI_EV_READ_CODE(EV_TRB_CODE,event)) */
end_process_tx_event:
if (ev_code >= MHI_EV_CC_OOB)
write_unlock_irqrestore(&mhi_chan->lock, flags);
else
read_unlock_bh(&mhi_chan->lock);
return 0;
}
static int parse_rsc_event(struct mhi_controller *mhi_cntrl,
struct mhi_ring_element *event,
struct mhi_chan *mhi_chan)
{
struct mhi_ring *buf_ring, *tre_ring;
struct mhi_buf_info *buf_info;
struct mhi_result result;
int ev_code;
u32 cookie; /* offset to local descriptor */
u16 xfer_len;
buf_ring = &mhi_chan->buf_ring;
tre_ring = &mhi_chan->tre_ring;
ev_code = MHI_TRE_GET_EV_CODE(event);
cookie = MHI_TRE_GET_EV_COOKIE(event);
xfer_len = MHI_TRE_GET_EV_LEN(event);
/* Received out of bound cookie */
WARN_ON(cookie >= buf_ring->len);
buf_info = buf_ring->base + cookie;
result.transaction_status = (ev_code == MHI_EV_CC_OVERFLOW) ?
-EOVERFLOW : 0;
/* truncate to buf len if xfer_len is larger */
result.bytes_xferd = min_t(u16, xfer_len, buf_info->len);
result.buf_addr = buf_info->cb_buf;
result.dir = mhi_chan->dir;
read_lock_bh(&mhi_chan->lock);
if (mhi_chan->ch_state != MHI_CH_STATE_ENABLED)
goto end_process_rsc_event;
WARN_ON(!buf_info->used);
/* notify the client */
mhi_chan->xfer_cb(mhi_chan->mhi_dev, &result);
/*
* Note: We're arbitrarily incrementing RP even though, completion
* packet we processed might not be the same one, reason we can do this
* is because device guaranteed to cache descriptors in order it
* receive, so even though completion event is different we can re-use
* all descriptors in between.
* Example:
* Transfer Ring has descriptors: A, B, C, D
* Last descriptor host queue is D (WP) and first descriptor
* host queue is A (RP).
* The completion event we just serviced is descriptor C.
* Then we can safely queue descriptors to replace A, B, and C
* even though host did not receive any completions.
*/
mhi_del_ring_element(mhi_cntrl, tre_ring);
buf_info->used = false;
end_process_rsc_event:
read_unlock_bh(&mhi_chan->lock);
return 0;
}
static void mhi_process_cmd_completion(struct mhi_controller *mhi_cntrl,
struct mhi_ring_element *tre)
{
dma_addr_t ptr = MHI_TRE_GET_EV_PTR(tre);
struct mhi_cmd *cmd_ring = &mhi_cntrl->mhi_cmd[PRIMARY_CMD_RING];
struct mhi_ring *mhi_ring = &cmd_ring->ring;
struct mhi_ring_element *cmd_pkt;
struct mhi_chan *mhi_chan;
u32 chan;
if (!is_valid_ring_ptr(mhi_ring, ptr)) {
dev_err(&mhi_cntrl->mhi_dev->dev,
"Event element points outside of the cmd ring\n");
return;
}
cmd_pkt = mhi_to_virtual(mhi_ring, ptr);
chan = MHI_TRE_GET_CMD_CHID(cmd_pkt);
if (chan < mhi_cntrl->max_chan &&
mhi_cntrl->mhi_chan[chan].configured) {
mhi_chan = &mhi_cntrl->mhi_chan[chan];
write_lock_bh(&mhi_chan->lock);
mhi_chan->ccs = MHI_TRE_GET_EV_CODE(tre);
complete(&mhi_chan->completion);
write_unlock_bh(&mhi_chan->lock);
} else {
dev_err(&mhi_cntrl->mhi_dev->dev,
"Completion packet for invalid channel ID: %d\n", chan);
}
mhi_del_ring_element(mhi_cntrl, mhi_ring);
}
int mhi_process_ctrl_ev_ring(struct mhi_controller *mhi_cntrl,
struct mhi_event *mhi_event,
u32 event_quota)
{
struct mhi_ring_element *dev_rp, *local_rp;
struct mhi_ring *ev_ring = &mhi_event->ring;
struct mhi_event_ctxt *er_ctxt =
&mhi_cntrl->mhi_ctxt->er_ctxt[mhi_event->er_index];
struct mhi_chan *mhi_chan;
struct device *dev = &mhi_cntrl->mhi_dev->dev;
u32 chan;
int count = 0;
dma_addr_t ptr = le64_to_cpu(er_ctxt->rp);
/*
* This is a quick check to avoid unnecessary event processing
* in case MHI is already in error state, but it's still possible
* to transition to error state while processing events
*/
if (unlikely(MHI_EVENT_ACCESS_INVALID(mhi_cntrl->pm_state)))
return -EIO;
if (!is_valid_ring_ptr(ev_ring, ptr)) {
dev_err(&mhi_cntrl->mhi_dev->dev,
"Event ring rp points outside of the event ring\n");
return -EIO;
}
dev_rp = mhi_to_virtual(ev_ring, ptr);
local_rp = ev_ring->rp;
while (dev_rp != local_rp) {
enum mhi_pkt_type type = MHI_TRE_GET_EV_TYPE(local_rp);
switch (type) {
case MHI_PKT_TYPE_BW_REQ_EVENT:
{
struct mhi_link_info *link_info;
link_info = &mhi_cntrl->mhi_link_info;
write_lock_irq(&mhi_cntrl->pm_lock);
link_info->target_link_speed =
MHI_TRE_GET_EV_LINKSPEED(local_rp);
link_info->target_link_width =
MHI_TRE_GET_EV_LINKWIDTH(local_rp);
write_unlock_irq(&mhi_cntrl->pm_lock);
dev_dbg(dev, "Received BW_REQ event\n");
mhi_cntrl->status_cb(mhi_cntrl, MHI_CB_BW_REQ);
break;
}
case MHI_PKT_TYPE_STATE_CHANGE_EVENT:
{
enum mhi_state new_state;
new_state = MHI_TRE_GET_EV_STATE(local_rp);
dev_dbg(dev, "State change event to state: %s\n",
mhi_state_str(new_state));
switch (new_state) {
case MHI_STATE_M0:
mhi_pm_m0_transition(mhi_cntrl);
break;
case MHI_STATE_M1:
mhi_pm_m1_transition(mhi_cntrl);
break;
case MHI_STATE_M3:
mhi_pm_m3_transition(mhi_cntrl);
break;
case MHI_STATE_SYS_ERR:
{
enum mhi_pm_state pm_state;
dev_dbg(dev, "System error detected\n");
write_lock_irq(&mhi_cntrl->pm_lock);
pm_state = mhi_tryset_pm_state(mhi_cntrl,
MHI_PM_SYS_ERR_DETECT);
write_unlock_irq(&mhi_cntrl->pm_lock);
if (pm_state == MHI_PM_SYS_ERR_DETECT)
mhi_pm_sys_err_handler(mhi_cntrl);
break;
}
default:
dev_err(dev, "Invalid state: %s\n",
mhi_state_str(new_state));
}
break;
}
case MHI_PKT_TYPE_CMD_COMPLETION_EVENT:
mhi_process_cmd_completion(mhi_cntrl, local_rp);
break;
case MHI_PKT_TYPE_EE_EVENT:
{
enum dev_st_transition st = DEV_ST_TRANSITION_MAX;
enum mhi_ee_type event = MHI_TRE_GET_EV_EXECENV(local_rp);
dev_dbg(dev, "Received EE event: %s\n",
TO_MHI_EXEC_STR(event));
switch (event) {
case MHI_EE_SBL:
st = DEV_ST_TRANSITION_SBL;
break;
case MHI_EE_WFW:
case MHI_EE_AMSS:
st = DEV_ST_TRANSITION_MISSION_MODE;
break;
case MHI_EE_FP:
st = DEV_ST_TRANSITION_FP;
break;
case MHI_EE_RDDM:
mhi_cntrl->status_cb(mhi_cntrl, MHI_CB_EE_RDDM);
write_lock_irq(&mhi_cntrl->pm_lock);
mhi_cntrl->ee = event;
write_unlock_irq(&mhi_cntrl->pm_lock);
wake_up_all(&mhi_cntrl->state_event);
break;
default:
dev_err(dev,
"Unhandled EE event: 0x%x\n", type);
}
if (st != DEV_ST_TRANSITION_MAX)
mhi_queue_state_transition(mhi_cntrl, st);
break;
}
case MHI_PKT_TYPE_TX_EVENT:
chan = MHI_TRE_GET_EV_CHID(local_rp);
WARN_ON(chan >= mhi_cntrl->max_chan);
/*
* Only process the event ring elements whose channel
* ID is within the maximum supported range.
*/
if (chan < mhi_cntrl->max_chan) {
mhi_chan = &mhi_cntrl->mhi_chan[chan];
if (!mhi_chan->configured)
break;
parse_xfer_event(mhi_cntrl, local_rp, mhi_chan);
}
break;
default:
dev_err(dev, "Unhandled event type: %d\n", type);
break;
}
mhi_recycle_ev_ring_element(mhi_cntrl, ev_ring);
local_rp = ev_ring->rp;
ptr = le64_to_cpu(er_ctxt->rp);
if (!is_valid_ring_ptr(ev_ring, ptr)) {
dev_err(&mhi_cntrl->mhi_dev->dev,
"Event ring rp points outside of the event ring\n");
return -EIO;
}
dev_rp = mhi_to_virtual(ev_ring, ptr);
count++;
}
read_lock_bh(&mhi_cntrl->pm_lock);
/* Ring EV DB only if there is any pending element to process */
if (likely(MHI_DB_ACCESS_VALID(mhi_cntrl)) && count)
mhi_ring_er_db(mhi_event);
read_unlock_bh(&mhi_cntrl->pm_lock);
return count;
}
int mhi_process_data_event_ring(struct mhi_controller *mhi_cntrl,
struct mhi_event *mhi_event,
u32 event_quota)
{
struct mhi_ring_element *dev_rp, *local_rp;
struct mhi_ring *ev_ring = &mhi_event->ring;
struct mhi_event_ctxt *er_ctxt =
&mhi_cntrl->mhi_ctxt->er_ctxt[mhi_event->er_index];
int count = 0;
u32 chan;
struct mhi_chan *mhi_chan;
dma_addr_t ptr = le64_to_cpu(er_ctxt->rp);
if (unlikely(MHI_EVENT_ACCESS_INVALID(mhi_cntrl->pm_state)))
return -EIO;
if (!is_valid_ring_ptr(ev_ring, ptr)) {
dev_err(&mhi_cntrl->mhi_dev->dev,
"Event ring rp points outside of the event ring\n");
return -EIO;
}
dev_rp = mhi_to_virtual(ev_ring, ptr);
local_rp = ev_ring->rp;
while (dev_rp != local_rp && event_quota > 0) {
enum mhi_pkt_type type = MHI_TRE_GET_EV_TYPE(local_rp);
chan = MHI_TRE_GET_EV_CHID(local_rp);
WARN_ON(chan >= mhi_cntrl->max_chan);
/*
* Only process the event ring elements whose channel
* ID is within the maximum supported range.
*/
if (chan < mhi_cntrl->max_chan &&
mhi_cntrl->mhi_chan[chan].configured) {
mhi_chan = &mhi_cntrl->mhi_chan[chan];
if (likely(type == MHI_PKT_TYPE_TX_EVENT)) {
parse_xfer_event(mhi_cntrl, local_rp, mhi_chan);
event_quota--;
} else if (type == MHI_PKT_TYPE_RSC_TX_EVENT) {
parse_rsc_event(mhi_cntrl, local_rp, mhi_chan);
event_quota--;
}
}
mhi_recycle_ev_ring_element(mhi_cntrl, ev_ring);
local_rp = ev_ring->rp;
ptr = le64_to_cpu(er_ctxt->rp);
if (!is_valid_ring_ptr(ev_ring, ptr)) {
dev_err(&mhi_cntrl->mhi_dev->dev,
"Event ring rp points outside of the event ring\n");
return -EIO;
}
dev_rp = mhi_to_virtual(ev_ring, ptr);
count++;
}
read_lock_bh(&mhi_cntrl->pm_lock);
/* Ring EV DB only if there is any pending element to process */
if (likely(MHI_DB_ACCESS_VALID(mhi_cntrl)) && count)
mhi_ring_er_db(mhi_event);
read_unlock_bh(&mhi_cntrl->pm_lock);
return count;
}
void mhi_ev_task(unsigned long data)
{
struct mhi_event *mhi_event = (struct mhi_event *)data;
struct mhi_controller *mhi_cntrl = mhi_event->mhi_cntrl;
/* process all pending events */
spin_lock_bh(&mhi_event->lock);
mhi_event->process_event(mhi_cntrl, mhi_event, U32_MAX);
spin_unlock_bh(&mhi_event->lock);
}
void mhi_ctrl_ev_task(unsigned long data)
{
struct mhi_event *mhi_event = (struct mhi_event *)data;
struct mhi_controller *mhi_cntrl = mhi_event->mhi_cntrl;
struct device *dev = &mhi_cntrl->mhi_dev->dev;
enum mhi_state state;
enum mhi_pm_state pm_state = 0;
int ret;
/*
* We can check PM state w/o a lock here because there is no way
* PM state can change from reg access valid to no access while this
* thread being executed.
*/
if (!MHI_REG_ACCESS_VALID(mhi_cntrl->pm_state)) {
/*
* We may have a pending event but not allowed to
* process it since we are probably in a suspended state,
* so trigger a resume.
*/
mhi_trigger_resume(mhi_cntrl);
return;
}
/* Process ctrl events */
ret = mhi_event->process_event(mhi_cntrl, mhi_event, U32_MAX);
/*
* We received an IRQ but no events to process, maybe device went to
* SYS_ERR state? Check the state to confirm.
*/
if (!ret) {
write_lock_irq(&mhi_cntrl->pm_lock);
state = mhi_get_mhi_state(mhi_cntrl);
if (state == MHI_STATE_SYS_ERR) {
dev_dbg(dev, "System error detected\n");
pm_state = mhi_tryset_pm_state(mhi_cntrl,
MHI_PM_SYS_ERR_DETECT);
}
write_unlock_irq(&mhi_cntrl->pm_lock);
if (pm_state == MHI_PM_SYS_ERR_DETECT)
mhi_pm_sys_err_handler(mhi_cntrl);
}
}
static bool mhi_is_ring_full(struct mhi_controller *mhi_cntrl,
struct mhi_ring *ring)
{
void *tmp = ring->wp + ring->el_size;
if (tmp >= (ring->base + ring->len))
tmp = ring->base;
return (tmp == ring->rp);
}
static int mhi_queue(struct mhi_device *mhi_dev, struct mhi_buf_info *buf_info,
enum dma_data_direction dir, enum mhi_flags mflags)
{
struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
struct mhi_chan *mhi_chan = (dir == DMA_TO_DEVICE) ? mhi_dev->ul_chan :
mhi_dev->dl_chan;
struct mhi_ring *tre_ring = &mhi_chan->tre_ring;
unsigned long flags;
int ret;
if (unlikely(MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)))
return -EIO;
ret = mhi_is_ring_full(mhi_cntrl, tre_ring);
if (unlikely(ret))
return -EAGAIN;
ret = mhi_gen_tre(mhi_cntrl, mhi_chan, buf_info, mflags);
if (unlikely(ret))
return ret;
read_lock_irqsave(&mhi_cntrl->pm_lock, flags);
/* Packet is queued, take a usage ref to exit M3 if necessary
* for host->device buffer, balanced put is done on buffer completion
* for device->host buffer, balanced put is after ringing the DB
*/
mhi_cntrl->runtime_get(mhi_cntrl);
/* Assert dev_wake (to exit/prevent M1/M2)*/
mhi_cntrl->wake_toggle(mhi_cntrl);
if (mhi_chan->dir == DMA_TO_DEVICE)
atomic_inc(&mhi_cntrl->pending_pkts);
if (likely(MHI_DB_ACCESS_VALID(mhi_cntrl)))
mhi_ring_chan_db(mhi_cntrl, mhi_chan);
if (dir == DMA_FROM_DEVICE)
mhi_cntrl->runtime_put(mhi_cntrl);
read_unlock_irqrestore(&mhi_cntrl->pm_lock, flags);
return ret;
}
int mhi_queue_skb(struct mhi_device *mhi_dev, enum dma_data_direction dir,
struct sk_buff *skb, size_t len, enum mhi_flags mflags)
{
struct mhi_chan *mhi_chan = (dir == DMA_TO_DEVICE) ? mhi_dev->ul_chan :
mhi_dev->dl_chan;
struct mhi_buf_info buf_info = { };
buf_info.v_addr = skb->data;
buf_info.cb_buf = skb;
buf_info.len = len;
if (unlikely(mhi_chan->pre_alloc))
return -EINVAL;
return mhi_queue(mhi_dev, &buf_info, dir, mflags);
}
EXPORT_SYMBOL_GPL(mhi_queue_skb);
int mhi_queue_dma(struct mhi_device *mhi_dev, enum dma_data_direction dir,
struct mhi_buf *mhi_buf, size_t len, enum mhi_flags mflags)
{
struct mhi_chan *mhi_chan = (dir == DMA_TO_DEVICE) ? mhi_dev->ul_chan :
mhi_dev->dl_chan;
struct mhi_buf_info buf_info = { };
buf_info.p_addr = mhi_buf->dma_addr;
buf_info.cb_buf = mhi_buf;
buf_info.pre_mapped = true;
buf_info.len = len;
if (unlikely(mhi_chan->pre_alloc))
return -EINVAL;
return mhi_queue(mhi_dev, &buf_info, dir, mflags);
}
EXPORT_SYMBOL_GPL(mhi_queue_dma);
int mhi_gen_tre(struct mhi_controller *mhi_cntrl, struct mhi_chan *mhi_chan,
struct mhi_buf_info *info, enum mhi_flags flags)
{
struct mhi_ring *buf_ring, *tre_ring;
struct mhi_ring_element *mhi_tre;
struct mhi_buf_info *buf_info;
int eot, eob, chain, bei;
int ret;
/* Protect accesses for reading and incrementing WP */
write_lock_bh(&mhi_chan->lock);
buf_ring = &mhi_chan->buf_ring;
tre_ring = &mhi_chan->tre_ring;
buf_info = buf_ring->wp;
WARN_ON(buf_info->used);
buf_info->pre_mapped = info->pre_mapped;
if (info->pre_mapped)
buf_info->p_addr = info->p_addr;
else
buf_info->v_addr = info->v_addr;
buf_info->cb_buf = info->cb_buf;
buf_info->wp = tre_ring->wp;
buf_info->dir = mhi_chan->dir;
buf_info->len = info->len;
if (!info->pre_mapped) {
ret = mhi_cntrl->map_single(mhi_cntrl, buf_info);
if (ret) {
write_unlock_bh(&mhi_chan->lock);
return ret;
}
}
eob = !!(flags & MHI_EOB);
eot = !!(flags & MHI_EOT);
chain = !!(flags & MHI_CHAIN);
bei = !!(mhi_chan->intmod);
mhi_tre = tre_ring->wp;
mhi_tre->ptr = MHI_TRE_DATA_PTR(buf_info->p_addr);
mhi_tre->dword[0] = MHI_TRE_DATA_DWORD0(info->len);
mhi_tre->dword[1] = MHI_TRE_DATA_DWORD1(bei, eot, eob, chain);
/* increment WP */
mhi_add_ring_element(mhi_cntrl, tre_ring);
mhi_add_ring_element(mhi_cntrl, buf_ring);
write_unlock_bh(&mhi_chan->lock);
return 0;
}
int mhi_queue_buf(struct mhi_device *mhi_dev, enum dma_data_direction dir,
void *buf, size_t len, enum mhi_flags mflags)
{
struct mhi_buf_info buf_info = { };
buf_info.v_addr = buf;
buf_info.cb_buf = buf;
buf_info.len = len;
return mhi_queue(mhi_dev, &buf_info, dir, mflags);
}
EXPORT_SYMBOL_GPL(mhi_queue_buf);
bool mhi_queue_is_full(struct mhi_device *mhi_dev, enum dma_data_direction dir)
{
struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
struct mhi_chan *mhi_chan = (dir == DMA_TO_DEVICE) ?
mhi_dev->ul_chan : mhi_dev->dl_chan;
struct mhi_ring *tre_ring = &mhi_chan->tre_ring;
return mhi_is_ring_full(mhi_cntrl, tre_ring);
}
EXPORT_SYMBOL_GPL(mhi_queue_is_full);
int mhi_send_cmd(struct mhi_controller *mhi_cntrl,
struct mhi_chan *mhi_chan,
enum mhi_cmd_type cmd)
{
struct mhi_ring_element *cmd_tre = NULL;
struct mhi_cmd *mhi_cmd = &mhi_cntrl->mhi_cmd[PRIMARY_CMD_RING];
struct mhi_ring *ring = &mhi_cmd->ring;
struct device *dev = &mhi_cntrl->mhi_dev->dev;
int chan = 0;
if (mhi_chan)
chan = mhi_chan->chan;
spin_lock_bh(&mhi_cmd->lock);
if (!get_nr_avail_ring_elements(mhi_cntrl, ring)) {
spin_unlock_bh(&mhi_cmd->lock);
return -ENOMEM;
}
/* prepare the cmd tre */
cmd_tre = ring->wp;
switch (cmd) {
case MHI_CMD_RESET_CHAN:
cmd_tre->ptr = MHI_TRE_CMD_RESET_PTR;
cmd_tre->dword[0] = MHI_TRE_CMD_RESET_DWORD0;
cmd_tre->dword[1] = MHI_TRE_CMD_RESET_DWORD1(chan);
break;
case MHI_CMD_STOP_CHAN:
cmd_tre->ptr = MHI_TRE_CMD_STOP_PTR;
cmd_tre->dword[0] = MHI_TRE_CMD_STOP_DWORD0;
cmd_tre->dword[1] = MHI_TRE_CMD_STOP_DWORD1(chan);
break;
case MHI_CMD_START_CHAN:
cmd_tre->ptr = MHI_TRE_CMD_START_PTR;
cmd_tre->dword[0] = MHI_TRE_CMD_START_DWORD0;
cmd_tre->dword[1] = MHI_TRE_CMD_START_DWORD1(chan);
break;
default:
dev_err(dev, "Command not supported\n");
break;
}
/* queue to hardware */
mhi_add_ring_element(mhi_cntrl, ring);
read_lock_bh(&mhi_cntrl->pm_lock);
if (likely(MHI_DB_ACCESS_VALID(mhi_cntrl)))
mhi_ring_cmd_db(mhi_cntrl, mhi_cmd);
read_unlock_bh(&mhi_cntrl->pm_lock);
spin_unlock_bh(&mhi_cmd->lock);
return 0;
}
static int mhi_update_channel_state(struct mhi_controller *mhi_cntrl,
struct mhi_chan *mhi_chan,
enum mhi_ch_state_type to_state)
{
struct device *dev = &mhi_chan->mhi_dev->dev;
enum mhi_cmd_type cmd = MHI_CMD_NOP;
int ret;
dev_dbg(dev, "%d: Updating channel state to: %s\n", mhi_chan->chan,
TO_CH_STATE_TYPE_STR(to_state));
switch (to_state) {
case MHI_CH_STATE_TYPE_RESET:
write_lock_irq(&mhi_chan->lock);
if (mhi_chan->ch_state != MHI_CH_STATE_STOP &&
mhi_chan->ch_state != MHI_CH_STATE_ENABLED &&
mhi_chan->ch_state != MHI_CH_STATE_SUSPENDED) {
write_unlock_irq(&mhi_chan->lock);
return -EINVAL;
}
mhi_chan->ch_state = MHI_CH_STATE_DISABLED;
write_unlock_irq(&mhi_chan->lock);
cmd = MHI_CMD_RESET_CHAN;
break;
case MHI_CH_STATE_TYPE_STOP:
if (mhi_chan->ch_state != MHI_CH_STATE_ENABLED)
return -EINVAL;
cmd = MHI_CMD_STOP_CHAN;
break;
case MHI_CH_STATE_TYPE_START:
if (mhi_chan->ch_state != MHI_CH_STATE_STOP &&
mhi_chan->ch_state != MHI_CH_STATE_DISABLED)
return -EINVAL;
cmd = MHI_CMD_START_CHAN;
break;
default:
dev_err(dev, "%d: Channel state update to %s not allowed\n",
mhi_chan->chan, TO_CH_STATE_TYPE_STR(to_state));
return -EINVAL;
}
/* bring host and device out of suspended states */
ret = mhi_device_get_sync(mhi_cntrl->mhi_dev);
if (ret)
return ret;
mhi_cntrl->runtime_get(mhi_cntrl);
reinit_completion(&mhi_chan->completion);
ret = mhi_send_cmd(mhi_cntrl, mhi_chan, cmd);
if (ret) {
dev_err(dev, "%d: Failed to send %s channel command\n",
mhi_chan->chan, TO_CH_STATE_TYPE_STR(to_state));
goto exit_channel_update;
}
ret = wait_for_completion_timeout(&mhi_chan->completion,
msecs_to_jiffies(mhi_cntrl->timeout_ms));
if (!ret || mhi_chan->ccs != MHI_EV_CC_SUCCESS) {
dev_err(dev,
"%d: Failed to receive %s channel command completion\n",
mhi_chan->chan, TO_CH_STATE_TYPE_STR(to_state));
ret = -EIO;
goto exit_channel_update;
}
ret = 0;
if (to_state != MHI_CH_STATE_TYPE_RESET) {
write_lock_irq(&mhi_chan->lock);
mhi_chan->ch_state = (to_state == MHI_CH_STATE_TYPE_START) ?
MHI_CH_STATE_ENABLED : MHI_CH_STATE_STOP;
write_unlock_irq(&mhi_chan->lock);
}
dev_dbg(dev, "%d: Channel state change to %s successful\n",
mhi_chan->chan, TO_CH_STATE_TYPE_STR(to_state));
exit_channel_update:
mhi_cntrl->runtime_put(mhi_cntrl);
mhi_device_put(mhi_cntrl->mhi_dev);
return ret;
}
static void mhi_unprepare_channel(struct mhi_controller *mhi_cntrl,
struct mhi_chan *mhi_chan)
{
int ret;
struct device *dev = &mhi_chan->mhi_dev->dev;
mutex_lock(&mhi_chan->mutex);
if (!(BIT(mhi_cntrl->ee) & mhi_chan->ee_mask)) {
dev_dbg(dev, "Current EE: %s Required EE Mask: 0x%x\n",
TO_MHI_EXEC_STR(mhi_cntrl->ee), mhi_chan->ee_mask);
goto exit_unprepare_channel;
}
/* no more processing events for this channel */
ret = mhi_update_channel_state(mhi_cntrl, mhi_chan,
MHI_CH_STATE_TYPE_RESET);
if (ret)
dev_err(dev, "%d: Failed to reset channel, still resetting\n",
mhi_chan->chan);
exit_unprepare_channel:
write_lock_irq(&mhi_chan->lock);
mhi_chan->ch_state = MHI_CH_STATE_DISABLED;
write_unlock_irq(&mhi_chan->lock);
if (!mhi_chan->offload_ch) {
mhi_reset_chan(mhi_cntrl, mhi_chan);
mhi_deinit_chan_ctxt(mhi_cntrl, mhi_chan);
}
dev_dbg(dev, "%d: successfully reset\n", mhi_chan->chan);
mutex_unlock(&mhi_chan->mutex);
}
int mhi_prepare_channel(struct mhi_controller *mhi_cntrl,
struct mhi_chan *mhi_chan, unsigned int flags)
{
int ret = 0;
struct device *dev = &mhi_chan->mhi_dev->dev;
if (!(BIT(mhi_cntrl->ee) & mhi_chan->ee_mask)) {
dev_err(dev, "Current EE: %s Required EE Mask: 0x%x\n",
TO_MHI_EXEC_STR(mhi_cntrl->ee), mhi_chan->ee_mask);
return -ENOTCONN;
}
mutex_lock(&mhi_chan->mutex);
/* Check of client manages channel context for offload channels */
if (!mhi_chan->offload_ch) {
ret = mhi_init_chan_ctxt(mhi_cntrl, mhi_chan);
if (ret)
goto error_init_chan;
}
ret = mhi_update_channel_state(mhi_cntrl, mhi_chan,
MHI_CH_STATE_TYPE_START);
if (ret)
goto error_pm_state;
if (mhi_chan->dir == DMA_FROM_DEVICE)
mhi_chan->pre_alloc = !!(flags & MHI_CH_INBOUND_ALLOC_BUFS);
/* Pre-allocate buffer for xfer ring */
if (mhi_chan->pre_alloc) {
int nr_el = get_nr_avail_ring_elements(mhi_cntrl,
&mhi_chan->tre_ring);
size_t len = mhi_cntrl->buffer_len;
while (nr_el--) {
void *buf;
struct mhi_buf_info info = { };
buf = kmalloc(len, GFP_KERNEL);
if (!buf) {
ret = -ENOMEM;
goto error_pre_alloc;
}
/* Prepare transfer descriptors */
info.v_addr = buf;
info.cb_buf = buf;
info.len = len;
ret = mhi_gen_tre(mhi_cntrl, mhi_chan, &info, MHI_EOT);
if (ret) {
kfree(buf);
goto error_pre_alloc;
}
}
read_lock_bh(&mhi_cntrl->pm_lock);
if (MHI_DB_ACCESS_VALID(mhi_cntrl)) {
read_lock_irq(&mhi_chan->lock);
mhi_ring_chan_db(mhi_cntrl, mhi_chan);
read_unlock_irq(&mhi_chan->lock);
}
read_unlock_bh(&mhi_cntrl->pm_lock);
}
mutex_unlock(&mhi_chan->mutex);
return 0;
error_pm_state:
if (!mhi_chan->offload_ch)
mhi_deinit_chan_ctxt(mhi_cntrl, mhi_chan);
error_init_chan:
mutex_unlock(&mhi_chan->mutex);
return ret;
error_pre_alloc:
mutex_unlock(&mhi_chan->mutex);
mhi_unprepare_channel(mhi_cntrl, mhi_chan);
return ret;
}
static void mhi_mark_stale_events(struct mhi_controller *mhi_cntrl,
struct mhi_event *mhi_event,
struct mhi_event_ctxt *er_ctxt,
int chan)
{
struct mhi_ring_element *dev_rp, *local_rp;
struct mhi_ring *ev_ring;
struct device *dev = &mhi_cntrl->mhi_dev->dev;
unsigned long flags;
dma_addr_t ptr;
dev_dbg(dev, "Marking all events for chan: %d as stale\n", chan);
ev_ring = &mhi_event->ring;
/* mark all stale events related to channel as STALE event */
spin_lock_irqsave(&mhi_event->lock, flags);
ptr = le64_to_cpu(er_ctxt->rp);
if (!is_valid_ring_ptr(ev_ring, ptr)) {
dev_err(&mhi_cntrl->mhi_dev->dev,
"Event ring rp points outside of the event ring\n");
dev_rp = ev_ring->rp;
} else {
dev_rp = mhi_to_virtual(ev_ring, ptr);
}
local_rp = ev_ring->rp;
while (dev_rp != local_rp) {
if (MHI_TRE_GET_EV_TYPE(local_rp) == MHI_PKT_TYPE_TX_EVENT &&
chan == MHI_TRE_GET_EV_CHID(local_rp))
local_rp->dword[1] = MHI_TRE_EV_DWORD1(chan,
MHI_PKT_TYPE_STALE_EVENT);
local_rp++;
if (local_rp == (ev_ring->base + ev_ring->len))
local_rp = ev_ring->base;
}
dev_dbg(dev, "Finished marking events as stale events\n");
spin_unlock_irqrestore(&mhi_event->lock, flags);
}
static void mhi_reset_data_chan(struct mhi_controller *mhi_cntrl,
struct mhi_chan *mhi_chan)
{
struct mhi_ring *buf_ring, *tre_ring;
struct mhi_result result;
/* Reset any pending buffers */
buf_ring = &mhi_chan->buf_ring;
tre_ring = &mhi_chan->tre_ring;
result.transaction_status = -ENOTCONN;
result.bytes_xferd = 0;
while (tre_ring->rp != tre_ring->wp) {
struct mhi_buf_info *buf_info = buf_ring->rp;
if (mhi_chan->dir == DMA_TO_DEVICE) {
atomic_dec(&mhi_cntrl->pending_pkts);
/* Release the reference got from mhi_queue() */
mhi_cntrl->runtime_put(mhi_cntrl);
}
if (!buf_info->pre_mapped)
mhi_cntrl->unmap_single(mhi_cntrl, buf_info);
mhi_del_ring_element(mhi_cntrl, buf_ring);
mhi_del_ring_element(mhi_cntrl, tre_ring);
if (mhi_chan->pre_alloc) {
kfree(buf_info->cb_buf);
} else {
result.buf_addr = buf_info->cb_buf;
mhi_chan->xfer_cb(mhi_chan->mhi_dev, &result);
}
}
}
void mhi_reset_chan(struct mhi_controller *mhi_cntrl, struct mhi_chan *mhi_chan)
{
struct mhi_event *mhi_event;
struct mhi_event_ctxt *er_ctxt;
int chan = mhi_chan->chan;
/* Nothing to reset, client doesn't queue buffers */
if (mhi_chan->offload_ch)
return;
read_lock_bh(&mhi_cntrl->pm_lock);
mhi_event = &mhi_cntrl->mhi_event[mhi_chan->er_index];
er_ctxt = &mhi_cntrl->mhi_ctxt->er_ctxt[mhi_chan->er_index];
mhi_mark_stale_events(mhi_cntrl, mhi_event, er_ctxt, chan);
mhi_reset_data_chan(mhi_cntrl, mhi_chan);
read_unlock_bh(&mhi_cntrl->pm_lock);
}
static int __mhi_prepare_for_transfer(struct mhi_device *mhi_dev, unsigned int flags)
{
int ret, dir;
struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
struct mhi_chan *mhi_chan;
for (dir = 0; dir < 2; dir++) {
mhi_chan = dir ? mhi_dev->dl_chan : mhi_dev->ul_chan;
if (!mhi_chan)
continue;
ret = mhi_prepare_channel(mhi_cntrl, mhi_chan, flags);
if (ret)
goto error_open_chan;
}
return 0;
error_open_chan:
for (--dir; dir >= 0; dir--) {
mhi_chan = dir ? mhi_dev->dl_chan : mhi_dev->ul_chan;
if (!mhi_chan)
continue;
mhi_unprepare_channel(mhi_cntrl, mhi_chan);
}
return ret;
}
int mhi_prepare_for_transfer(struct mhi_device *mhi_dev)
{
return __mhi_prepare_for_transfer(mhi_dev, 0);
}
EXPORT_SYMBOL_GPL(mhi_prepare_for_transfer);
int mhi_prepare_for_transfer_autoqueue(struct mhi_device *mhi_dev)
{
return __mhi_prepare_for_transfer(mhi_dev, MHI_CH_INBOUND_ALLOC_BUFS);
}
EXPORT_SYMBOL_GPL(mhi_prepare_for_transfer_autoqueue);
void mhi_unprepare_from_transfer(struct mhi_device *mhi_dev)
{
struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
struct mhi_chan *mhi_chan;
int dir;
for (dir = 0; dir < 2; dir++) {
mhi_chan = dir ? mhi_dev->ul_chan : mhi_dev->dl_chan;
if (!mhi_chan)
continue;
mhi_unprepare_channel(mhi_cntrl, mhi_chan);
}
}
EXPORT_SYMBOL_GPL(mhi_unprepare_from_transfer);
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