diff options
Diffstat (limited to 'drivers/bus/mhi/host/main.c')
| -rw-r--r-- | drivers/bus/mhi/host/main.c | 1696 |
1 files changed, 1696 insertions, 0 deletions
diff --git a/drivers/bus/mhi/host/main.c b/drivers/bus/mhi/host/main.c new file mode 100644 index 000000000000..df0fbfee7b78 --- /dev/null +++ b/drivers/bus/mhi/host/main.c @@ -0,0 +1,1696 @@ +// 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) +{ + int ret; + u32 out, retry = (mhi_cntrl->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; +} + +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 || ee == mhi_cntrl->ee) + 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); + event_quota--; + } + 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); + if (likely(MHI_DB_ACCESS_VALID(mhi_cntrl))) + 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); + if (likely(MHI_DB_ACCESS_VALID(mhi_cntrl))) + 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; + + read_lock_irqsave(&mhi_cntrl->pm_lock, flags); + + ret = mhi_is_ring_full(mhi_cntrl, tre_ring); + if (unlikely(ret)) { + ret = -EAGAIN; + goto exit_unlock; + } + + ret = mhi_gen_tre(mhi_cntrl, mhi_chan, buf_info, mflags); + if (unlikely(ret)) + goto exit_unlock; + + /* 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); + +exit_unlock: + 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; + + 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) + 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); + + 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); + +int mhi_poll(struct mhi_device *mhi_dev, u32 budget) +{ + struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl; + struct mhi_chan *mhi_chan = mhi_dev->dl_chan; + struct mhi_event *mhi_event = &mhi_cntrl->mhi_event[mhi_chan->er_index]; + int ret; + + spin_lock_bh(&mhi_event->lock); + ret = mhi_event->process_event(mhi_cntrl, mhi_event, budget); + spin_unlock_bh(&mhi_event->lock); + + return ret; +} +EXPORT_SYMBOL_GPL(mhi_poll); |