Serialize execution environment changes for MHI
Subsystems (2)
cover Serialize execution environment changes for MHI
During full boot chain firmware download, the PM state worker downloads the AMSS image after waiting for the SBL execution environment change in PBL mode itself. Since getting rid of the firmware load worker thread, this design needs to change and MHI host must download the AMSS image from the SBL mode of PM state worker thread instead.
Also ensure that EE changes are handled only from appropriate places and occur one after another and handle only PBL or RDDM EE changes as critical events directly from the interrupt handler and the status callback is given to the controller drivers promptly.
Bhaumik Bhatt (2):
bus: mhi: core: Download AMSS image from appropriate function
bus: mhi: core: Process execution environment changes serially
drivers/bus/mhi/core/boot.c | 44 ++++++++++++++++++++--------------------- drivers/bus/mhi/core/internal.h | 1 + drivers/bus/mhi/core/main.c | 14 +++++++------ drivers/bus/mhi/core/pm.c | 14 +++++++++---- 4 files changed, 40 insertions(+), 33 deletions(-)
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PATCH 1/2 bus: mhi: core: Download AMSS image from appropriate function
During full boot chain firmware download, the PM state worker downloads the AMSS image after waiting for the SBL execution environment change in PBL mode itself. Since getting rid of the firmware load worker thread, this design needs to change and MHI host must download the AMSS image from the SBL mode of PM state worker thread instead. Since the full boot chain firmware download is associated with a synchronous power up and has MHI host waiting for a transition to mission mode with a timeout, we can skip creating any devices (or probing any client drivers) in SBL mode transition and proceed directly with the AMSS image download.
This means that if MHI host driver is not responsible for the AMSS image download or the controller plans to have client drivers opening any SBL channels, for example, to download images or monitor debug logs for memory allocations or power management, the device can be powered up asynchronously.
--- drivers/bus/mhi/core/boot.c | 44 ++++++++++++++++++++--------------------- drivers/bus/mhi/core/internal.h | 1 + drivers/bus/mhi/core/pm.c | 8 ++++++-- 3 files changed, 28 insertions(+), 25 deletions(-)
drivers/bus/mhi/core/boot.c +21 -23
@@ -389,7 +389,6 @@ static void mhi_firmware_copy(struct mhi_controller *mhi_cntrl,void mhi_fw_load_handler (struct mhi_controller *mhi_cntrl) {const struct firmware *firmware =NULL ; -struct image_info *image_info;struct device *dev = &mhi_cntrl->mhi_dev->dev;const char *fw_name;void *buf;
@@ -500,28 +499,6 @@ void mhi_fw_load_handler(struct mhi_controller *mhi_cntrl) goto error_ready_state; } -/* Wait for the SBL event */ - ret =wait_event_timeout (mhi_cntrl->state_event, - mhi_cntrl->ee ==MHI_EE_SBL || -MHI_PM_IN_ERROR_STATE (mhi_cntrl->pm_state), -msecs_to_jiffies (mhi_cntrl->timeout_ms)); - -if (!ret ||MHI_PM_IN_ERROR_STATE (mhi_cntrl->pm_state)) { -dev_err (dev,"MHI did not enter SBL\n" ); - goto error_ready_state; - } - -/* Start full firmware image download */ - image_info = mhi_cntrl->fbc_image; - ret =mhi_fw_load_bhie (mhi_cntrl, -/* Vector table is the last entry */ - &image_info->mhi_buf[image_info->entries -1 ]); -if (ret) { -dev_err (dev,"MHI did not load image over BHIe, ret: %d\n" , - ret); - goto error_fw_load; - } -return ; error_ready_state:
@@ -532,3 +509,24 @@ void mhi_fw_load_handler(struct mhi_controller *mhi_cntrl) mhi_cntrl->pm_state =MHI_PM_FW_DL_ERR ;wake_up_all (&mhi_cntrl->state_event); } + +int mhi_download_amss_image (struct mhi_controller *mhi_cntrl) +{ +struct image_info *image_info = mhi_cntrl->fbc_image; +struct device *dev = &mhi_cntrl->mhi_dev->dev; +int ret; + +if (!image_info) +return -EIO ; + + ret =mhi_fw_load_bhie (mhi_cntrl, +/* Vector table is the last entry */ + &image_info->mhi_buf[image_info->entries -1 ]); +if (ret) { +dev_err (dev,"MHI did not load AMSS, ret:%d\n" , ret); + mhi_cntrl->pm_state =MHI_PM_FW_DL_ERR ; +wake_up_all (&mhi_cntrl->state_event); + } + +return ret; +}
drivers/bus/mhi/core/internal.h +1 -0
@@ -619,6 +619,7 @@ int mhi_pm_m3_transition(struct mhi_controller *mhi_cntrl);int __mhi_device_get_sync (struct mhi_controller *mhi_cntrl);int mhi_send_cmd (struct mhi_controller *mhi_cntrl,struct mhi_chan *mhi_chan,enum mhi_cmd_type cmd); +int mhi_download_amss_image (struct mhi_controller *mhi_cntrl);static inline bool mhi_is_active (struct mhi_controller *mhi_cntrl) { return (mhi_cntrl->dev_state >= MHI_STATE_M0 &&
drivers/bus/mhi/core/pm.c +6 -2
@@ -752,9 +752,13 @@ void mhi_pm_st_worker(struct work_struct *work)/* * The MHI devices are only created when the client * device switches its Execution Environment (EE) to -* either SBL or AMSS states +* either SBL or AMSS states. If FBC download is +* expected, we do not create devices in SBL. */ -mhi_create_devices (mhi_cntrl); +if (mhi_cntrl->fbc_download) +mhi_download_amss_image (mhi_cntrl); +else +mhi_create_devices (mhi_cntrl);break ;case DEV_ST_TRANSITION_MISSION_MODE :mhi_pm_mission_mode_transition (mhi_cntrl);
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PATCH 2/2 bus: mhi: core: Process execution environment changes serially
In reply to Bhaumik BhattIn current design, whenever the BHI interrupt is fired, the execution environment is updated. This can cause race conditions and impede any ongoing power up/down processing. For example, if a power down is in progress and the host has updated the execution environment to a local "disabled" state, any BHI interrupt firing later could replace it with the value from the BHI EE register. Another example would be that the device can enter mission mode while device creation for SBL is still going on, leading to multiple attempts at opening the same channel.
Ensure that EE changes are handled only from appropriate places and occur one after another and handle only PBL or RDDM EE changes as critical events directly from the interrupt handler. This also makes sure that we use the correct execution environment to notify the controller driver when the device resets to one of the PBL execution environments.
--- drivers/bus/mhi/core/main.c | 14 ++++++++------ drivers/bus/mhi/core/pm.c | 6 ++++-- 2 files changed, 12 insertions(+), 8 deletions(-)
drivers/bus/mhi/core/main.c +8 -6
@@ -377,7 +377,7 @@ irqreturn_t mhi_intvec_threaded_handler(int irq_number, void *priv)struct device *dev = &mhi_cntrl->mhi_dev->dev;enum mhi_state state =MHI_STATE_MAX ;enum mhi_pm_state pm_state =0 ; -enum mhi_ee_type ee =0 ; +enum mhi_ee_type ee =MHI_EE_MAX ;write_lock_irq (&mhi_cntrl->pm_lock);if (!MHI_REG_ACCESS_VALID (mhi_cntrl->pm_state)) {
@@ -386,8 +386,7 @@ irqreturn_t mhi_intvec_threaded_handler(int irq_number, void *priv) } state =mhi_get_mhi_state (mhi_cntrl); - ee = mhi_cntrl->ee; - mhi_cntrl->ee =mhi_get_exec_env (mhi_cntrl); + ee =mhi_get_exec_env (mhi_cntrl);dev_dbg (dev,"local ee:%s device ee:%s dev_state:%s\n" ,TO_MHI_EXEC_STR (mhi_cntrl->ee),TO_MHI_EXEC_STR (ee),TO_MHI_STATE_STR (state));
@@ -405,8 +404,9 @@ irqreturn_t mhi_intvec_threaded_handler(int irq_number, void *priv)if (!mhi_is_active (mhi_cntrl)) goto exit_intvec; -if (mhi_cntrl->ee ==MHI_EE_RDDM && mhi_cntrl->ee != ee) { +if (ee ==MHI_EE_RDDM && mhi_cntrl->ee !=MHI_EE_RDDM ) { mhi_cntrl->status_cb (mhi_cntrl,MHI_CB_EE_RDDM ); + mhi_cntrl->ee = ee;wake_up_all (&mhi_cntrl->state_event); } goto exit_intvec;
@@ -416,10 +416,12 @@ irqreturn_t mhi_intvec_threaded_handler(int irq_number, void *priv)wake_up_all (&mhi_cntrl->state_event);/* For fatal errors, we let controller decide next step */ -if (MHI_IN_PBL (ee)) +if (MHI_IN_PBL (ee)) { mhi_cntrl->status_cb (mhi_cntrl,MHI_CB_FATAL_ERROR ); -else + mhi_cntrl->ee = ee; + }else {mhi_pm_sys_err_handler (mhi_cntrl); + } } exit_intvec:
drivers/bus/mhi/core/pm.c +4 -2
@@ -377,20 +377,22 @@ static int mhi_pm_mission_mode_transition(struct mhi_controller *mhi_cntrl) {struct mhi_event *mhi_event;struct device *dev = &mhi_cntrl->mhi_dev->dev; +enum mhi_ee_type ee =MHI_EE_MAX ;int i, ret;dev_dbg (dev,"Processing Mission Mode transition\n" );write_lock_irq (&mhi_cntrl->pm_lock);if (MHI_REG_ACCESS_VALID (mhi_cntrl->pm_state)) - mhi_cntrl->ee =mhi_get_exec_env (mhi_cntrl); + ee =mhi_get_exec_env (mhi_cntrl); -if (!MHI_IN_MISSION_MODE (mhi_cntrl->ee)) { +if (!MHI_IN_MISSION_MODE (ee)) { mhi_cntrl->pm_state =MHI_PM_LD_ERR_FATAL_DETECT ;write_unlock_irq (&mhi_cntrl->pm_lock);wake_up_all (&mhi_cntrl->state_event);return -EIO ; } + mhi_cntrl->ee = ee;write_unlock_irq (&mhi_cntrl->pm_lock);wake_up_all (&mhi_cntrl->state_event);
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