[PATCH 00/18] MHI changes for v5.10

[PATCH 00/18] MHI changes for v5.10

[Manivannan Sadhasivam]

Hi Greg,

Here is the MHI series for v5.10 cycle. Most of the patches are cleanups
in the MHI stack. Notable changes are below:

* Saving the client device hardware information obtained through the BHI
  protocol. This information will be exposed through sysfs to make use in
  the userland applications.
* Introduce sysfs entries to read the serial number and OEM PK hash values
  of the client device obtained from BHI protocol. Relevant API documentation
  is also added.
* Introduce debugfs entries to show MHI states, events, channels, register
  state etc... to aid debug.
* Fix the warning reported by Kbuild bot by using append (+=) Kbuild rule
  to the mhi/core Makefile.
* Removed the requirement to have a dedicated IRQ for each event ring.
  The MHI controllers can now use a single IRQ for all event rings.

Please consider merging!

Thanks,
Mani

Bhaumik Bhatt (12):
  bus: mhi: core: Remove double occurrence for mhi_ctrl_ev_task()
    declaration
  bus: mhi: core: Abort suspends due to outgoing pending packets
  bus: mhi: core: Use helper API to trigger a non-blocking host resume
  bus: mhi: core: Trigger host resume if suspended during
    mhi_device_get()
  bus: mhi: core: Use generic name field for an MHI device
  bus: mhi: core: Introduce helper function to check device state
  bus: mhi: core: Introduce counters to track MHI device state
    transitions
  bus: mhi: core: Read and save device hardware information from BHI
  bus: mhi: core: Introduce APIs to allocate and free the MHI controller
  bus: mhi: Fix entries based on Kconfig coding style
  bus: mhi: core: Introduce debugfs entries for MHI
  bus: mhi: core: Introduce sysfs entries for MHI

Clark Williams (1):
  bus: mhi: Remove include of rwlock_types.h

Hemant Kumar (1):
  bus: mhi: core: Add const qualifier to MHI config information

Loic Poulain (2):
  bus: mhi: core: Allow shared IRQ for event rings
  bus: mhi: Remove unused nr_irqs_req variable

Manivannan Sadhasivam (1):
  bus: mhi: core: Fix the building of MHI module

Randy Dunlap (1):
  bus: mhi: fix doubled words and struct image_info kernel-doc

 Documentation/ABI/stable/sysfs-bus-mhi |  21 ++
 MAINTAINERS                            |   1 +
 drivers/bus/mhi/Kconfig                |  20 +-
 drivers/bus/mhi/core/Makefile          |   3 +-
 drivers/bus/mhi/core/boot.c            |  17 +-
 drivers/bus/mhi/core/debugfs.c         | 410 +++++++++++++++++++++++++
 drivers/bus/mhi/core/init.c            | 103 ++++++-
 drivers/bus/mhi/core/internal.h        |  37 ++-
 drivers/bus/mhi/core/main.c            |  27 +-
 drivers/bus/mhi/core/pm.c              |  28 +-
 include/linux/mhi.h                    |  51 ++-
 11 files changed, 654 insertions(+), 64 deletions(-)
 create mode 100644 Documentation/ABI/stable/sysfs-bus-mhi
 create mode 100644 drivers/bus/mhi/core/debugfs.c

-- 
2.17.1

[PATCH] bus: mhi: core: Fix the building of MHI module

[Manivannan Sadhasivam]

The Kbuild rule to build MHI should use the append operator. This fixes
the below warning reported by Kbuild test bot.

WARNING: modpost: missing MODULE_LICENSE() in
drivers/bus/mhi/core/main.o
WARNING: modpost: missing MODULE_LICENSE() in drivers/bus/mhi/core/pm.o
WARNING: modpost: missing MODULE_LICENSE() in
drivers/bus/mhi/core/boot.o

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/bus/mhi/core/Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/bus/mhi/core/Makefile b/drivers/bus/mhi/core/Makefile
index 12c57ab3724c..c3feb4130aa3 100644
--- a/drivers/bus/mhi/core/Makefile
+++ b/drivers/bus/mhi/core/Makefile
@@ -1,4 +1,4 @@
-obj-$(CONFIG_MHI_BUS) := mhi.o
+obj-$(CONFIG_MHI_BUS) += mhi.o
 
 mhi-y := init.o main.o pm.o boot.o
 mhi-$(CONFIG_MHI_BUS_DEBUG) += debugfs.o
-- 
2.17.1

Re: [PATCH] bus: mhi: core: Fix the building of MHI module

[Manivannan Sadhasivam]

On Mon, Sep 21, 2020 at 09:37:57PM +0530, Manivannan Sadhasivam wrote:
> The Kbuild rule to build MHI should use the append operator. This fixes
> the below warning reported by Kbuild test bot.
> 
> WARNING: modpost: missing MODULE_LICENSE() in
> drivers/bus/mhi/core/main.o
> WARNING: modpost: missing MODULE_LICENSE() in drivers/bus/mhi/core/pm.o
> WARNING: modpost: missing MODULE_LICENSE() in
> drivers/bus/mhi/core/boot.o
> 
> Reported-by: kernel test robot <lkp@intel.com>
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

Oops! This one sneaked in. Please ignore this patch as it is already included
in the series.

Thanks,
Mani

> ---
>  drivers/bus/mhi/core/Makefile | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/bus/mhi/core/Makefile b/drivers/bus/mhi/core/Makefile
> index 12c57ab3724c..c3feb4130aa3 100644
> --- a/drivers/bus/mhi/core/Makefile
> +++ b/drivers/bus/mhi/core/Makefile
> @@ -1,4 +1,4 @@
> -obj-$(CONFIG_MHI_BUS) := mhi.o
> +obj-$(CONFIG_MHI_BUS) += mhi.o
>  
>  mhi-y := init.o main.o pm.o boot.o
>  mhi-$(CONFIG_MHI_BUS_DEBUG) += debugfs.o
> -- 
> 2.17.1
> 

[PATCH 01/18] bus: mhi: fix doubled words and struct image_info kernel-doc

[Manivannan Sadhasivam]

From: Randy Dunlap <rdunlap@infradead.org>

Drop doubled word "table" in kernel-doc.
Fix syntax for the kernel-doc notation for struct image_info.
Note that the bhi_vec field is private and not part of the kernel-doc.

Drop doubled word "device" in a comment.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Cc: Hemant Kumar <hemantk@codeaurora.org>
Cc: linux-arm-msm@vger.kernel.org
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
[mani: Added bus: prefix to the commit subject]
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 include/linux/mhi.h | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/include/linux/mhi.h b/include/linux/mhi.h
index c4a940d98912..0779bc689b3e 100644
--- a/include/linux/mhi.h
+++ b/include/linux/mhi.h
@@ -85,13 +85,15 @@ enum mhi_ch_type {
 };
 
 /**
- * struct image_info - Firmware and RDDM table table
- * @mhi_buf - Buffer for firmware and RDDM table
- * @entries - # of entries in table
+ * struct image_info - Firmware and RDDM table
+ * @mhi_buf: Buffer for firmware and RDDM table
+ * @entries: # of entries in table
  */
 struct image_info {
 	struct mhi_buf *mhi_buf;
+	/* private: from internal.h */
 	struct bhi_vec_entry *bhi_vec;
+	/* public: */
 	u32 entries;
 };
 
@@ -593,7 +595,7 @@ int mhi_async_power_up(struct mhi_controller *mhi_cntrl);
 
 /**
  * mhi_sync_power_up - Start MHI power up sequence and wait till the device
- *                     device enters valid EE state
+ *                     enters valid EE state
  * @mhi_cntrl: MHI controller
  */
 int mhi_sync_power_up(struct mhi_controller *mhi_cntrl);
-- 
2.17.1

[PATCH 02/18] bus: mhi: core: Remove double occurrence for mhi_ctrl_ev_task() declaration

[Manivannan Sadhasivam]

From: Bhaumik Bhatt <bbhatt@codeaurora.org>

mhi_ctrl_ev_task() in the internal header file occurred twice.
Remove one of the occurrences for clean-up.

Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/bus/mhi/core/internal.h | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/bus/mhi/core/internal.h b/drivers/bus/mhi/core/internal.h
index b1f640b75a94..bcfa7b6558ef 100644
--- a/drivers/bus/mhi/core/internal.h
+++ b/drivers/bus/mhi/core/internal.h
@@ -592,7 +592,6 @@ void mhi_pm_st_worker(struct work_struct *work);
 void mhi_pm_sys_err_handler(struct mhi_controller *mhi_cntrl);
 void mhi_fw_load_worker(struct work_struct *work);
 int mhi_ready_state_transition(struct mhi_controller *mhi_cntrl);
-void mhi_ctrl_ev_task(unsigned long data);
 int mhi_pm_m0_transition(struct mhi_controller *mhi_cntrl);
 void mhi_pm_m1_transition(struct mhi_controller *mhi_cntrl);
 int mhi_pm_m3_transition(struct mhi_controller *mhi_cntrl);
-- 
2.17.1

[PATCH 03/18] bus: mhi: core: Abort suspends due to outgoing pending packets

[Manivannan Sadhasivam]

From: Bhaumik Bhatt <bbhatt@codeaurora.org>

Add the missing check to abort suspends if a client driver has pending
outgoing packets to send to the device. This allows better utilization
of the MHI bus wherein clients on the host are not left waiting for
longer suspend or resume cycles to finish for data transfers.

Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/bus/mhi/core/pm.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c
index 796098078083..661d704c8093 100644
--- a/drivers/bus/mhi/core/pm.c
+++ b/drivers/bus/mhi/core/pm.c
@@ -686,7 +686,8 @@ int mhi_pm_suspend(struct mhi_controller *mhi_cntrl)
 		return -EIO;
 
 	/* Return busy if there are any pending resources */
-	if (atomic_read(&mhi_cntrl->dev_wake))
+	if (atomic_read(&mhi_cntrl->dev_wake) ||
+	    atomic_read(&mhi_cntrl->pending_pkts))
 		return -EBUSY;
 
 	/* Take MHI out of M2 state */
@@ -712,7 +713,8 @@ int mhi_pm_suspend(struct mhi_controller *mhi_cntrl)
 
 	write_lock_irq(&mhi_cntrl->pm_lock);
 
-	if (atomic_read(&mhi_cntrl->dev_wake)) {
+	if (atomic_read(&mhi_cntrl->dev_wake) ||
+	    atomic_read(&mhi_cntrl->pending_pkts)) {
 		write_unlock_irq(&mhi_cntrl->pm_lock);
 		return -EBUSY;
 	}
-- 
2.17.1

[PATCH 04/18] bus: mhi: core: Use helper API to trigger a non-blocking host resume

[Manivannan Sadhasivam]

From: Bhaumik Bhatt <bbhatt@codeaurora.org>

Autonomous low power mode support requires the MHI host to resume from
multiple places and post a wakeup source to exit system suspend. This
needs to be done in a non-blocking manner. Introduce a helper API to
trigger the host resume for data transfers and other non-blocking use
cases while supporting implementation of autonomous low power modes.

Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/bus/mhi/core/internal.h |  7 +++++++
 drivers/bus/mhi/core/main.c     | 21 +++++++--------------
 drivers/bus/mhi/core/pm.c       | 13 ++++---------
 3 files changed, 18 insertions(+), 23 deletions(-)

diff --git a/drivers/bus/mhi/core/internal.h b/drivers/bus/mhi/core/internal.h
index bcfa7b6558ef..1bbd6e99d38d 100644
--- a/drivers/bus/mhi/core/internal.h
+++ b/drivers/bus/mhi/core/internal.h
@@ -599,6 +599,13 @@ 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);
 
+static inline void mhi_trigger_resume(struct mhi_controller *mhi_cntrl)
+{
+	pm_wakeup_event(&mhi_cntrl->mhi_dev->dev, 0);
+	mhi_cntrl->runtime_get(mhi_cntrl);
+	mhi_cntrl->runtime_put(mhi_cntrl);
+}
+
 /* Register access methods */
 void mhi_db_brstmode(struct mhi_controller *mhi_cntrl, struct db_cfg *db_cfg,
 		     void __iomem *db_addr, dma_addr_t db_val);
diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c
index 1f622ce6be8b..79be18ec2ebf 100644
--- a/drivers/bus/mhi/core/main.c
+++ b/drivers/bus/mhi/core/main.c
@@ -909,8 +909,7 @@ void mhi_ctrl_ev_task(unsigned long data)
 		 * process it since we are probably in a suspended state,
 		 * so trigger a resume.
 		 */
-		mhi_cntrl->runtime_get(mhi_cntrl);
-		mhi_cntrl->runtime_put(mhi_cntrl);
+		mhi_trigger_resume(mhi_cntrl);
 
 		return;
 	}
@@ -971,10 +970,8 @@ int mhi_queue_skb(struct mhi_device *mhi_dev, enum dma_data_direction dir,
 	}
 
 	/* we're in M3 or transitioning to M3 */
-	if (MHI_PM_IN_SUSPEND_STATE(mhi_cntrl->pm_state)) {
-		mhi_cntrl->runtime_get(mhi_cntrl);
-		mhi_cntrl->runtime_put(mhi_cntrl);
-	}
+	if (MHI_PM_IN_SUSPEND_STATE(mhi_cntrl->pm_state))
+		mhi_trigger_resume(mhi_cntrl);
 
 	/* Toggle wake to exit out of M2 */
 	mhi_cntrl->wake_toggle(mhi_cntrl);
@@ -1032,10 +1029,8 @@ int mhi_queue_dma(struct mhi_device *mhi_dev, enum dma_data_direction dir,
 	}
 
 	/* we're in M3 or transitioning to M3 */
-	if (MHI_PM_IN_SUSPEND_STATE(mhi_cntrl->pm_state)) {
-		mhi_cntrl->runtime_get(mhi_cntrl);
-		mhi_cntrl->runtime_put(mhi_cntrl);
-	}
+	if (MHI_PM_IN_SUSPEND_STATE(mhi_cntrl->pm_state))
+		mhi_trigger_resume(mhi_cntrl);
 
 	/* Toggle wake to exit out of M2 */
 	mhi_cntrl->wake_toggle(mhi_cntrl);
@@ -1147,10 +1142,8 @@ int mhi_queue_buf(struct mhi_device *mhi_dev, enum dma_data_direction dir,
 	read_lock_irqsave(&mhi_cntrl->pm_lock, flags);
 
 	/* we're in M3 or transitioning to M3 */
-	if (MHI_PM_IN_SUSPEND_STATE(mhi_cntrl->pm_state)) {
-		mhi_cntrl->runtime_get(mhi_cntrl);
-		mhi_cntrl->runtime_put(mhi_cntrl);
-	}
+	if (MHI_PM_IN_SUSPEND_STATE(mhi_cntrl->pm_state))
+		mhi_trigger_resume(mhi_cntrl);
 
 	/* Toggle wake to exit out of M2 */
 	mhi_cntrl->wake_toggle(mhi_cntrl);
diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c
index 661d704c8093..b227d415e937 100644
--- a/drivers/bus/mhi/core/pm.c
+++ b/drivers/bus/mhi/core/pm.c
@@ -824,11 +824,8 @@ int __mhi_device_get_sync(struct mhi_controller *mhi_cntrl)
 	/* Wake up the device */
 	read_lock_bh(&mhi_cntrl->pm_lock);
 	mhi_cntrl->wake_get(mhi_cntrl, true);
-	if (MHI_PM_IN_SUSPEND_STATE(mhi_cntrl->pm_state)) {
-		pm_wakeup_event(&mhi_cntrl->mhi_dev->dev, 0);
-		mhi_cntrl->runtime_get(mhi_cntrl);
-		mhi_cntrl->runtime_put(mhi_cntrl);
-	}
+	if (MHI_PM_IN_SUSPEND_STATE(mhi_cntrl->pm_state))
+		mhi_trigger_resume(mhi_cntrl);
 	read_unlock_bh(&mhi_cntrl->pm_lock);
 
 	ret = wait_event_timeout(mhi_cntrl->state_event,
@@ -1139,10 +1136,8 @@ void mhi_device_put(struct mhi_device *mhi_dev)
 
 	mhi_dev->dev_wake--;
 	read_lock_bh(&mhi_cntrl->pm_lock);
-	if (MHI_PM_IN_SUSPEND_STATE(mhi_cntrl->pm_state)) {
-		mhi_cntrl->runtime_get(mhi_cntrl);
-		mhi_cntrl->runtime_put(mhi_cntrl);
-	}
+	if (MHI_PM_IN_SUSPEND_STATE(mhi_cntrl->pm_state))
+		mhi_trigger_resume(mhi_cntrl);
 
 	mhi_cntrl->wake_put(mhi_cntrl, false);
 	read_unlock_bh(&mhi_cntrl->pm_lock);
-- 
2.17.1

[PATCH 05/18] bus: mhi: core: Trigger host resume if suspended during mhi_device_get()

[Manivannan Sadhasivam]

From: Bhaumik Bhatt <bbhatt@codeaurora.org>

It is possible that the host may be suspending or suspended and may
not allow an outgoing device wake assert immediately if a client has
requested for it. Ensure that the host wakes up and allows for it so
the client does not have to wait for an external trigger or an
outgoing packet to be queued for the host resume to occur.

Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/bus/mhi/core/pm.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c
index b227d415e937..27bb471c8f4e 100644
--- a/drivers/bus/mhi/core/pm.c
+++ b/drivers/bus/mhi/core/pm.c
@@ -1112,6 +1112,9 @@ void mhi_device_get(struct mhi_device *mhi_dev)
 
 	mhi_dev->dev_wake++;
 	read_lock_bh(&mhi_cntrl->pm_lock);
+	if (MHI_PM_IN_SUSPEND_STATE(mhi_cntrl->pm_state))
+		mhi_trigger_resume(mhi_cntrl);
+
 	mhi_cntrl->wake_get(mhi_cntrl, true);
 	read_unlock_bh(&mhi_cntrl->pm_lock);
 }
-- 
2.17.1

[PATCH 06/18] bus: mhi: core: Use generic name field for an MHI device

[Manivannan Sadhasivam]

From: Bhaumik Bhatt <bbhatt@codeaurora.org>

An MHI device is not necessarily associated with only channels as we can
have one associated with the controller itself. Hence, the chan_name
field within the mhi_device structure should instead be replaced with a
generic name to accurately reflect any type of MHI device.

Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: Jeffrey Hugo <jhugo@codeaurora.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/bus/mhi/core/init.c | 5 +++--
 drivers/bus/mhi/core/main.c | 6 +++---
 include/linux/mhi.h         | 8 ++++----
 3 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
index e43a190a7a36..e2011ec46b92 100644
--- a/drivers/bus/mhi/core/init.c
+++ b/drivers/bus/mhi/core/init.c
@@ -904,6 +904,7 @@ int mhi_register_controller(struct mhi_controller *mhi_cntrl,
 	mhi_dev->dev_type = MHI_DEVICE_CONTROLLER;
 	mhi_dev->mhi_cntrl = mhi_cntrl;
 	dev_set_name(&mhi_dev->dev, "%s", dev_name(mhi_cntrl->cntrl_dev));
+	mhi_dev->name = dev_name(mhi_cntrl->cntrl_dev);
 
 	/* Init wakeup source */
 	device_init_wakeup(&mhi_dev->dev, true);
@@ -1249,7 +1250,7 @@ static int mhi_uevent(struct device *dev, struct kobj_uevent_env *env)
 	struct mhi_device *mhi_dev = to_mhi_device(dev);
 
 	return add_uevent_var(env, "MODALIAS=" MHI_DEVICE_MODALIAS_FMT,
-					mhi_dev->chan_name);
+					mhi_dev->name);
 }
 
 static int mhi_match(struct device *dev, struct device_driver *drv)
@@ -1266,7 +1267,7 @@ static int mhi_match(struct device *dev, struct device_driver *drv)
 		return 0;
 
 	for (id = mhi_drv->id_table; id->chan[0]; id++)
-		if (!strcmp(mhi_dev->chan_name, id->chan)) {
+		if (!strcmp(mhi_dev->name, id->chan)) {
 			mhi_dev->id = id;
 			return 1;
 		}
diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c
index 79be18ec2ebf..2cff5ddff225 100644
--- a/drivers/bus/mhi/core/main.c
+++ b/drivers/bus/mhi/core/main.c
@@ -249,7 +249,7 @@ int mhi_destroy_device(struct device *dev, void *data)
 		put_device(&mhi_dev->dl_chan->mhi_dev->dev);
 
 	dev_dbg(&mhi_cntrl->mhi_dev->dev, "destroy device for chan:%s\n",
-		 mhi_dev->chan_name);
+		 mhi_dev->name);
 
 	/* Notify the client and remove the device from MHI bus */
 	device_del(dev);
@@ -327,10 +327,10 @@ void mhi_create_devices(struct mhi_controller *mhi_cntrl)
 		}
 
 		/* Channel name is same for both UL and DL */
-		mhi_dev->chan_name = mhi_chan->name;
+		mhi_dev->name = mhi_chan->name;
 		dev_set_name(&mhi_dev->dev, "%s_%s",
 			     dev_name(mhi_cntrl->cntrl_dev),
-			     mhi_dev->chan_name);
+			     mhi_dev->name);
 
 		/* Init wakeup source if available */
 		if (mhi_dev->dl_chan && mhi_dev->dl_chan->wake_capable)
diff --git a/include/linux/mhi.h b/include/linux/mhi.h
index 0779bc689b3e..bb337d163dda 100644
--- a/include/linux/mhi.h
+++ b/include/linux/mhi.h
@@ -438,10 +438,10 @@ struct mhi_controller {
 };
 
 /**
- * struct mhi_device - Structure representing a MHI device which binds
- *                     to channels
+ * struct mhi_device - Structure representing an MHI device which binds
+ *                     to channels or is associated with controllers
  * @id: Pointer to MHI device ID struct
- * @chan_name: Name of the channel to which the device binds
+ * @name: Name of the associated MHI device
  * @mhi_cntrl: Controller the device belongs to
  * @ul_chan: UL channel for the device
  * @dl_chan: DL channel for the device
@@ -453,7 +453,7 @@ struct mhi_controller {
  */
 struct mhi_device {
 	const struct mhi_device_id *id;
-	const char *chan_name;
+	const char *name;
 	struct mhi_controller *mhi_cntrl;
 	struct mhi_chan *ul_chan;
 	struct mhi_chan *dl_chan;
-- 
2.17.1

[PATCH 07/18] bus: mhi: core: Introduce helper function to check device state

[Manivannan Sadhasivam]

From: Bhaumik Bhatt <bbhatt@codeaurora.org>

Introduce a helper function to determine whether the device is in a
powered ON state and resides in one of the active MHI states. This will
allow for some use cases where access can be pre-determined.

Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: Jeffrey Hugo <jhugo@codeaurora.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/bus/mhi/core/internal.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/bus/mhi/core/internal.h b/drivers/bus/mhi/core/internal.h
index 1bbd6e99d38d..5a81a428c4aa 100644
--- a/drivers/bus/mhi/core/internal.h
+++ b/drivers/bus/mhi/core/internal.h
@@ -598,6 +598,11 @@ 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);
+static inline bool mhi_is_active(struct mhi_controller *mhi_cntrl)
+{
+	return (mhi_cntrl->dev_state >= MHI_STATE_M0 &&
+		mhi_cntrl->dev_state <= MHI_STATE_M3_FAST);
+}
 
 static inline void mhi_trigger_resume(struct mhi_controller *mhi_cntrl)
 {
-- 
2.17.1

[PATCH 08/18] bus: mhi: core: Introduce counters to track MHI device state transitions

[Manivannan Sadhasivam]

From: Bhaumik Bhatt <bbhatt@codeaurora.org>

Use counters to track MHI device state transitions such as those
to M0, M2, or M3 states. This can help in better debug, allowing
the user to see the number of transitions to a certain MHI state
when queried using debugfs entries or via other mechanisms.

Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/bus/mhi/core/pm.c | 4 ++++
 include/linux/mhi.h       | 2 ++
 2 files changed, 6 insertions(+)

diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c
index 27bb471c8f4e..ce4d969818b4 100644
--- a/drivers/bus/mhi/core/pm.c
+++ b/drivers/bus/mhi/core/pm.c
@@ -256,6 +256,7 @@ int mhi_pm_m0_transition(struct mhi_controller *mhi_cntrl)
 		dev_err(dev, "Unable to transition to M0 state\n");
 		return -EIO;
 	}
+	mhi_cntrl->M0++;
 
 	/* Wake up the device */
 	read_lock_bh(&mhi_cntrl->pm_lock);
@@ -326,6 +327,8 @@ void mhi_pm_m1_transition(struct mhi_controller *mhi_cntrl)
 		mhi_cntrl->dev_state = MHI_STATE_M2;
 
 		write_unlock_irq(&mhi_cntrl->pm_lock);
+
+		mhi_cntrl->M2++;
 		wake_up_all(&mhi_cntrl->state_event);
 
 		/* If there are any pending resources, exit M2 immediately */
@@ -362,6 +365,7 @@ int mhi_pm_m3_transition(struct mhi_controller *mhi_cntrl)
 		return -EIO;
 	}
 
+	mhi_cntrl->M3++;
 	wake_up_all(&mhi_cntrl->state_event);
 
 	return 0;
diff --git a/include/linux/mhi.h b/include/linux/mhi.h
index bb337d163dda..c56b4447a4e9 100644
--- a/include/linux/mhi.h
+++ b/include/linux/mhi.h
@@ -328,6 +328,7 @@ struct mhi_controller_config {
  * @dev_state: MHI device state
  * @dev_wake: Device wakeup count
  * @pending_pkts: Pending packets for the controller
+ * @M0, M2, M3: Counters to track number of device MHI state changes
  * @transition_list: List of MHI state transitions
  * @transition_lock: Lock for protecting MHI state transition list
  * @wlock: Lock for protecting device wakeup
@@ -407,6 +408,7 @@ struct mhi_controller {
 	enum mhi_state dev_state;
 	atomic_t dev_wake;
 	atomic_t pending_pkts;
+	u32 M0, M2, M3;
 	struct list_head transition_list;
 	spinlock_t transition_lock;
 	spinlock_t wlock;
-- 
2.17.1

[PATCH 09/18] bus: mhi: core: Read and save device hardware information from BHI

[Manivannan Sadhasivam]

From: Bhaumik Bhatt <bbhatt@codeaurora.org>

Device hardware specific information such as serial number and the OEM
PK hash can be read using BHI and saved on host to identify the
endpoint.

Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: Jeffrey Hugo <jhugo@codeaurora.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/bus/mhi/core/boot.c | 17 ++++++++++++++++-
 include/linux/mhi.h         |  6 ++++++
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/drivers/bus/mhi/core/boot.c b/drivers/bus/mhi/core/boot.c
index 0b38014d040e..24422f5c3d80 100644
--- a/drivers/bus/mhi/core/boot.c
+++ b/drivers/bus/mhi/core/boot.c
@@ -392,13 +392,28 @@ void mhi_fw_load_handler(struct mhi_controller *mhi_cntrl)
 	void *buf;
 	dma_addr_t dma_addr;
 	size_t size;
-	int ret;
+	int i, ret;
 
 	if (MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)) {
 		dev_err(dev, "Device MHI is not in valid state\n");
 		return;
 	}
 
+	/* save hardware info from BHI */
+	ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->bhi, BHI_SERIALNU,
+			   &mhi_cntrl->serial_number);
+	if (ret)
+		dev_err(dev, "Could not capture serial number via BHI\n");
+
+	for (i = 0; i < ARRAY_SIZE(mhi_cntrl->oem_pk_hash); i++) {
+		ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->bhi, BHI_OEMPKHASH(i),
+				   &mhi_cntrl->oem_pk_hash[i]);
+		if (ret) {
+			dev_err(dev, "Could not capture OEM PK HASH via BHI\n");
+			break;
+		}
+	}
+
 	/* If device is in pass through, do reset to ready state transition */
 	if (mhi_cntrl->ee == MHI_EE_PTHRU)
 		goto fw_load_ee_pthru;
diff --git a/include/linux/mhi.h b/include/linux/mhi.h
index c56b4447a4e9..0c97f4bc5fae 100644
--- a/include/linux/mhi.h
+++ b/include/linux/mhi.h
@@ -16,6 +16,8 @@
 #include <linux/wait.h>
 #include <linux/workqueue.h>
 
+#define MHI_MAX_OEM_PK_HASH_SEGMENTS 16
+
 struct mhi_chan;
 struct mhi_event;
 struct mhi_ctxt;
@@ -316,6 +318,8 @@ struct mhi_controller_config {
  * @device_number: MHI controller device number
  * @major_version: MHI controller major revision number
  * @minor_version: MHI controller minor revision number
+ * @serial_number: MHI controller serial number obtained from BHI
+ * @oem_pk_hash: MHI controller OEM PK Hash obtained from BHI
  * @mhi_event: MHI event ring configurations table
  * @mhi_cmd: MHI command ring configurations table
  * @mhi_ctxt: MHI device context, shared memory between host and device
@@ -394,6 +398,8 @@ struct mhi_controller {
 	u32 device_number;
 	u32 major_version;
 	u32 minor_version;
+	u32 serial_number;
+	u32 oem_pk_hash[MHI_MAX_OEM_PK_HASH_SEGMENTS];
 
 	struct mhi_event *mhi_event;
 	struct mhi_cmd *mhi_cmd;
-- 
2.17.1

[PATCH 10/18] bus: mhi: core: Introduce APIs to allocate and free the MHI controller

[Manivannan Sadhasivam]

From: Bhaumik Bhatt <bbhatt@codeaurora.org>

Client devices should use the APIs provided to allocate and free
the MHI controller structure. This will help ensure that the
structure is zero-initialized and there are no false positives
with respect to reading any values such as the serial number or
the OEM PK hash.

Suggested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/bus/mhi/core/init.c | 16 ++++++++++++++++
 include/linux/mhi.h         | 12 ++++++++++++
 2 files changed, 28 insertions(+)

diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
index e2011ec46b92..f69a2f3d039d 100644
--- a/drivers/bus/mhi/core/init.c
+++ b/drivers/bus/mhi/core/init.c
@@ -954,6 +954,22 @@ void mhi_unregister_controller(struct mhi_controller *mhi_cntrl)
 }
 EXPORT_SYMBOL_GPL(mhi_unregister_controller);
 
+struct mhi_controller *mhi_alloc_controller(void)
+{
+	struct mhi_controller *mhi_cntrl;
+
+	mhi_cntrl = kzalloc(sizeof(*mhi_cntrl), GFP_KERNEL);
+
+	return mhi_cntrl;
+}
+EXPORT_SYMBOL_GPL(mhi_alloc_controller);
+
+void mhi_free_controller(struct mhi_controller *mhi_cntrl)
+{
+	kfree(mhi_cntrl);
+}
+EXPORT_SYMBOL_GPL(mhi_free_controller);
+
 int mhi_prepare_for_power_up(struct mhi_controller *mhi_cntrl)
 {
 	struct device *dev = &mhi_cntrl->mhi_dev->dev;
diff --git a/include/linux/mhi.h b/include/linux/mhi.h
index 0c97f4bc5fae..6b987e8cc438 100644
--- a/include/linux/mhi.h
+++ b/include/linux/mhi.h
@@ -527,6 +527,18 @@ struct mhi_driver {
 #define to_mhi_driver(drv) container_of(drv, struct mhi_driver, driver)
 #define to_mhi_device(dev) container_of(dev, struct mhi_device, dev)
 
+/**
+ * mhi_alloc_controller - Allocate the MHI Controller structure
+ * Allocate the mhi_controller structure using zero initialized memory
+ */
+struct mhi_controller *mhi_alloc_controller(void);
+
+/**
+ * mhi_free_controller - Free the MHI Controller structure
+ * Free the mhi_controller structure which was previously allocated
+ */
+void mhi_free_controller(struct mhi_controller *mhi_cntrl);
+
 /**
  * mhi_register_controller - Register MHI controller
  * @mhi_cntrl: MHI controller to register
-- 
2.17.1

[PATCH 11/18] bus: mhi: core: Add const qualifier to MHI config information

[Manivannan Sadhasivam]

From: Hemant Kumar <hemantk@codeaurora.org>

MHI channel, event and controller config data needs to be
treated read only information. Add const qualifier to make
sure config information passed by MHI controller is not
modified by MHI core driver.

Suggested-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Hemant Kumar <hemantk@codeaurora.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/bus/mhi/core/init.c | 12 ++++++------
 include/linux/mhi.h         |  6 +++---
 2 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
index f69a2f3d039d..d23293876be8 100644
--- a/drivers/bus/mhi/core/init.c
+++ b/drivers/bus/mhi/core/init.c
@@ -562,10 +562,10 @@ int mhi_init_chan_ctxt(struct mhi_controller *mhi_cntrl,
 }
 
 static int parse_ev_cfg(struct mhi_controller *mhi_cntrl,
-			struct mhi_controller_config *config)
+			const struct mhi_controller_config *config)
 {
 	struct mhi_event *mhi_event;
-	struct mhi_event_config *event_cfg;
+	const struct mhi_event_config *event_cfg;
 	struct device *dev = &mhi_cntrl->mhi_dev->dev;
 	int i, num;
 
@@ -648,9 +648,9 @@ static int parse_ev_cfg(struct mhi_controller *mhi_cntrl,
 }
 
 static int parse_ch_cfg(struct mhi_controller *mhi_cntrl,
-			struct mhi_controller_config *config)
+			const struct mhi_controller_config *config)
 {
-	struct mhi_channel_config *ch_cfg;
+	const struct mhi_channel_config *ch_cfg;
 	struct device *dev = &mhi_cntrl->mhi_dev->dev;
 	int i;
 	u32 chan;
@@ -766,7 +766,7 @@ static int parse_ch_cfg(struct mhi_controller *mhi_cntrl,
 }
 
 static int parse_config(struct mhi_controller *mhi_cntrl,
-			struct mhi_controller_config *config)
+			const struct mhi_controller_config *config)
 {
 	int ret;
 
@@ -803,7 +803,7 @@ static int parse_config(struct mhi_controller *mhi_cntrl,
 }
 
 int mhi_register_controller(struct mhi_controller *mhi_cntrl,
-			    struct mhi_controller_config *config)
+			    const struct mhi_controller_config *config)
 {
 	struct mhi_event *mhi_event;
 	struct mhi_chan *mhi_chan;
diff --git a/include/linux/mhi.h b/include/linux/mhi.h
index 6b987e8cc438..b2c0214bfbd6 100644
--- a/include/linux/mhi.h
+++ b/include/linux/mhi.h
@@ -280,9 +280,9 @@ struct mhi_controller_config {
 	u32 timeout_ms;
 	u32 buf_len;
 	u32 num_channels;
-	struct mhi_channel_config *ch_cfg;
+	const struct mhi_channel_config *ch_cfg;
 	u32 num_events;
-	struct mhi_event_config *event_cfg;
+	const struct mhi_event_config *event_cfg;
 	bool use_bounce_buf;
 	bool m2_no_db;
 };
@@ -545,7 +545,7 @@ void mhi_free_controller(struct mhi_controller *mhi_cntrl);
  * @config: Configuration to use for the controller
  */
 int mhi_register_controller(struct mhi_controller *mhi_cntrl,
-			    struct mhi_controller_config *config);
+			const struct mhi_controller_config *config);
 
 /**
  * mhi_unregister_controller - Unregister MHI controller
-- 
2.17.1

[PATCH 12/18] bus: mhi: Remove include of rwlock_types.h

[Manivannan Sadhasivam]

From: Clark Williams <williams@redhat.com>

rwlock.h should not be included directly. Instead linux/splinlock.h
should be included. Including it directly will break the RT build.

Also there is no point in including _types.h headers directly. There is
no benefit in including the type without the accessor.

Fixes: 0cbf260820fa7 ("bus: mhi: core: Add support for registering MHI controllers")
Signed-off-by: Clark Williams <williams@redhat.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 include/linux/mhi.h | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/include/linux/mhi.h b/include/linux/mhi.h
index b2c0214bfbd6..008b8f6fa9ff 100644
--- a/include/linux/mhi.h
+++ b/include/linux/mhi.h
@@ -9,10 +9,9 @@
 #include <linux/device.h>
 #include <linux/dma-direction.h>
 #include <linux/mutex.h>
-#include <linux/rwlock_types.h>
 #include <linux/skbuff.h>
 #include <linux/slab.h>
-#include <linux/spinlock_types.h>
+#include <linux/spinlock.h>
 #include <linux/wait.h>
 #include <linux/workqueue.h>
 
-- 
2.17.1

[PATCH 13/18] bus: mhi: Fix entries based on Kconfig coding style

[Manivannan Sadhasivam]

From: Bhaumik Bhatt <bbhatt@codeaurora.org>

Kconfig coding style mandates use of tabs for the configuration
definition and an additional two spaces for the help text. Make the
required changes to the MHI Kconfig adhering to those guidelines.

Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/bus/mhi/Kconfig | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/bus/mhi/Kconfig b/drivers/bus/mhi/Kconfig
index a8bd9bd7db7c..6677cccd61f3 100644
--- a/drivers/bus/mhi/Kconfig
+++ b/drivers/bus/mhi/Kconfig
@@ -6,9 +6,9 @@
 #
 
 config MHI_BUS
-       tristate "Modem Host Interface (MHI) bus"
-       help
-	 Bus driver for MHI protocol. Modem Host Interface (MHI) is a
-	 communication protocol used by the host processors to control
-	 and communicate with modem devices over a high speed peripheral
-	 bus or shared memory.
+	tristate "Modem Host Interface (MHI) bus"
+	help
+	  Bus driver for MHI protocol. Modem Host Interface (MHI) is a
+	  communication protocol used by the host processors to control
+	  and communicate with modem devices over a high speed peripheral
+	  bus or shared memory.
-- 
2.17.1

[PATCH 14/18] bus: mhi: core: Introduce debugfs entries for MHI

[Manivannan Sadhasivam]

From: Bhaumik Bhatt <bbhatt@codeaurora.org>

Introduce debugfs entries to show state, register, channel, device,
and event rings information. Allow the host to dump registers,
issue device wake, and change the MHI timeout to help in debug.

Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/bus/mhi/Kconfig         |   8 +
 drivers/bus/mhi/core/Makefile   |   1 +
 drivers/bus/mhi/core/debugfs.c  | 410 ++++++++++++++++++++++++++++++++
 drivers/bus/mhi/core/init.c     |   7 +
 drivers/bus/mhi/core/internal.h |  24 ++
 include/linux/mhi.h             |   2 +
 6 files changed, 452 insertions(+)
 create mode 100644 drivers/bus/mhi/core/debugfs.c

diff --git a/drivers/bus/mhi/Kconfig b/drivers/bus/mhi/Kconfig
index 6677cccd61f3..e841c1097fb4 100644
--- a/drivers/bus/mhi/Kconfig
+++ b/drivers/bus/mhi/Kconfig
@@ -12,3 +12,11 @@ config MHI_BUS
 	  communication protocol used by the host processors to control
 	  and communicate with modem devices over a high speed peripheral
 	  bus or shared memory.
+
+config MHI_BUS_DEBUG
+	bool "Debugfs support for the MHI bus"
+	depends on MHI_BUS && DEBUG_FS
+	help
+	  Enable debugfs support for use with the MHI transport. Allows
+	  reading and/or modifying some values within the MHI controller
+	  for debug and test purposes.
diff --git a/drivers/bus/mhi/core/Makefile b/drivers/bus/mhi/core/Makefile
index 66e2700c9032..12c57ab3724c 100644
--- a/drivers/bus/mhi/core/Makefile
+++ b/drivers/bus/mhi/core/Makefile
@@ -1,3 +1,4 @@
 obj-$(CONFIG_MHI_BUS) := mhi.o
 
 mhi-y := init.o main.o pm.o boot.o
+mhi-$(CONFIG_MHI_BUS_DEBUG) += debugfs.o
diff --git a/drivers/bus/mhi/core/debugfs.c b/drivers/bus/mhi/core/debugfs.c
new file mode 100644
index 000000000000..53d05a8e168d
--- /dev/null
+++ b/drivers/bus/mhi/core/debugfs.c
@@ -0,0 +1,410 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2020, The Linux Foundation. All rights reserved.
+ *
+ */
+
+#include <linux/debugfs.h>
+#include <linux/device.h>
+#include <linux/interrupt.h>
+#include <linux/list.h>
+#include <linux/mhi.h>
+#include <linux/module.h>
+#include "internal.h"
+
+static int mhi_debugfs_states_show(struct seq_file *m, void *d)
+{
+	struct mhi_controller *mhi_cntrl = m->private;
+
+	/* states */
+	seq_printf(m, "PM state: %s Device: %s MHI state: %s EE: %s wake: %s\n",
+		   to_mhi_pm_state_str(mhi_cntrl->pm_state),
+		   mhi_is_active(mhi_cntrl) ? "Active" : "Inactive",
+		   TO_MHI_STATE_STR(mhi_cntrl->dev_state),
+		   TO_MHI_EXEC_STR(mhi_cntrl->ee),
+		   mhi_cntrl->wake_set ? "true" : "false");
+
+	/* counters */
+	seq_printf(m, "M0: %u M2: %u M3: %u", mhi_cntrl->M0, mhi_cntrl->M2,
+		   mhi_cntrl->M3);
+
+	seq_printf(m, " device wake: %u pending packets: %u\n",
+		   atomic_read(&mhi_cntrl->dev_wake),
+		   atomic_read(&mhi_cntrl->pending_pkts));
+
+	return 0;
+}
+
+static int mhi_debugfs_events_show(struct seq_file *m, void *d)
+{
+	struct mhi_controller *mhi_cntrl = m->private;
+	struct mhi_event *mhi_event;
+	struct mhi_event_ctxt *er_ctxt;
+	int i;
+
+	if (!mhi_is_active(mhi_cntrl)) {
+		seq_puts(m, "Device not ready\n");
+		return -ENODEV;
+	}
+
+	er_ctxt = mhi_cntrl->mhi_ctxt->er_ctxt;
+	mhi_event = mhi_cntrl->mhi_event;
+	for (i = 0; i < mhi_cntrl->total_ev_rings;
+						i++, er_ctxt++, mhi_event++) {
+		struct mhi_ring *ring = &mhi_event->ring;
+
+		if (mhi_event->offload_ev) {
+			seq_printf(m, "Index: %d is an offload event ring\n",
+				   i);
+			continue;
+		}
+
+		seq_printf(m, "Index: %d intmod count: %lu time: %lu",
+			   i, (er_ctxt->intmod & EV_CTX_INTMODC_MASK) >>
+			   EV_CTX_INTMODC_SHIFT,
+			   (er_ctxt->intmod & EV_CTX_INTMODT_MASK) >>
+			   EV_CTX_INTMODT_SHIFT);
+
+		seq_printf(m, " base: 0x%0llx len: 0x%llx", er_ctxt->rbase,
+			   er_ctxt->rlen);
+
+		seq_printf(m, " rp: 0x%llx wp: 0x%llx", er_ctxt->rp,
+			   er_ctxt->wp);
+
+		seq_printf(m, " local rp: 0x%llx db: 0x%llx\n", (u64)ring->rp,
+			   mhi_event->db_cfg.db_val);
+	}
+
+	return 0;
+}
+
+static int mhi_debugfs_channels_show(struct seq_file *m, void *d)
+{
+	struct mhi_controller *mhi_cntrl = m->private;
+	struct mhi_chan *mhi_chan;
+	struct mhi_chan_ctxt *chan_ctxt;
+	int i;
+
+	if (!mhi_is_active(mhi_cntrl)) {
+		seq_puts(m, "Device not ready\n");
+		return -ENODEV;
+	}
+
+	mhi_chan = mhi_cntrl->mhi_chan;
+	chan_ctxt = mhi_cntrl->mhi_ctxt->chan_ctxt;
+	for (i = 0; i < mhi_cntrl->max_chan; i++, chan_ctxt++, mhi_chan++) {
+		struct mhi_ring *ring = &mhi_chan->tre_ring;
+
+		if (mhi_chan->offload_ch) {
+			seq_printf(m, "%s(%u) is an offload channel\n",
+				   mhi_chan->name, mhi_chan->chan);
+			continue;
+		}
+
+		if (!mhi_chan->mhi_dev)
+			continue;
+
+		seq_printf(m,
+			   "%s(%u) state: 0x%lx brstmode: 0x%lx pollcfg: 0x%lx",
+			   mhi_chan->name, mhi_chan->chan, (chan_ctxt->chcfg &
+			   CHAN_CTX_CHSTATE_MASK) >> CHAN_CTX_CHSTATE_SHIFT,
+			   (chan_ctxt->chcfg & CHAN_CTX_BRSTMODE_MASK) >>
+			   CHAN_CTX_BRSTMODE_SHIFT, (chan_ctxt->chcfg &
+			   CHAN_CTX_POLLCFG_MASK) >> CHAN_CTX_POLLCFG_SHIFT);
+
+		seq_printf(m, " type: 0x%x event ring: %u", chan_ctxt->chtype,
+			   chan_ctxt->erindex);
+
+		seq_printf(m, " base: 0x%llx len: 0x%llx wp: 0x%llx",
+			   chan_ctxt->rbase, chan_ctxt->rlen, chan_ctxt->wp);
+
+		seq_printf(m, " local rp: 0x%llx local wp: 0x%llx db: 0x%llx\n",
+			   (u64)ring->rp, (u64)ring->wp,
+			   mhi_chan->db_cfg.db_val);
+	}
+
+	return 0;
+}
+
+static int mhi_device_info_show(struct device *dev, void *data)
+{
+	struct mhi_device *mhi_dev;
+
+	if (dev->bus != &mhi_bus_type)
+		return 0;
+
+	mhi_dev = to_mhi_device(dev);
+
+	seq_printf((struct seq_file *)data, "%s: type: %s dev_wake: %u",
+		   mhi_dev->name, mhi_dev->dev_type ? "Controller" : "Transfer",
+		   mhi_dev->dev_wake);
+
+	/* for transfer device types only */
+	if (mhi_dev->dev_type == MHI_DEVICE_XFER)
+		seq_printf((struct seq_file *)data, " channels: %u(UL)/%u(DL)",
+			   mhi_dev->ul_chan_id, mhi_dev->dl_chan_id);
+
+	seq_puts((struct seq_file *)data, "\n");
+
+	return 0;
+}
+
+static int mhi_debugfs_devices_show(struct seq_file *m, void *d)
+{
+	struct mhi_controller *mhi_cntrl = m->private;
+
+	if (!mhi_is_active(mhi_cntrl)) {
+		seq_puts(m, "Device not ready\n");
+		return -ENODEV;
+	}
+
+	device_for_each_child(mhi_cntrl->cntrl_dev, m, mhi_device_info_show);
+
+	return 0;
+}
+
+static int mhi_debugfs_regdump_show(struct seq_file *m, void *d)
+{
+	struct mhi_controller *mhi_cntrl = m->private;
+	enum mhi_state state;
+	enum mhi_ee_type ee;
+	int i, ret = -EIO;
+	u32 val;
+	void __iomem *mhi_base = mhi_cntrl->regs;
+	void __iomem *bhi_base = mhi_cntrl->bhi;
+	void __iomem *bhie_base = mhi_cntrl->bhie;
+	void __iomem *wake_db = mhi_cntrl->wake_db;
+	struct {
+		const char *name;
+		int offset;
+		void __iomem *base;
+	} regs[] = {
+		{ "MHI_REGLEN", MHIREGLEN, mhi_base},
+		{ "MHI_VER", MHIVER, mhi_base},
+		{ "MHI_CFG", MHICFG, mhi_base},
+		{ "MHI_CTRL", MHICTRL, mhi_base},
+		{ "MHI_STATUS", MHISTATUS, mhi_base},
+		{ "MHI_WAKE_DB", 0, wake_db},
+		{ "BHI_EXECENV", BHI_EXECENV, bhi_base},
+		{ "BHI_STATUS", BHI_STATUS, bhi_base},
+		{ "BHI_ERRCODE", BHI_ERRCODE, bhi_base},
+		{ "BHI_ERRDBG1", BHI_ERRDBG1, bhi_base},
+		{ "BHI_ERRDBG2", BHI_ERRDBG2, bhi_base},
+		{ "BHI_ERRDBG3", BHI_ERRDBG3, bhi_base},
+		{ "BHIE_TXVEC_DB", BHIE_TXVECDB_OFFS, bhie_base},
+		{ "BHIE_TXVEC_STATUS", BHIE_TXVECSTATUS_OFFS, bhie_base},
+		{ "BHIE_RXVEC_DB", BHIE_RXVECDB_OFFS, bhie_base},
+		{ "BHIE_RXVEC_STATUS", BHIE_RXVECSTATUS_OFFS, bhie_base},
+		{ NULL },
+	};
+
+	if (!MHI_REG_ACCESS_VALID(mhi_cntrl->pm_state))
+		return ret;
+
+	seq_printf(m, "Host PM state: %s Device state: %s EE: %s\n",
+		   to_mhi_pm_state_str(mhi_cntrl->pm_state),
+		   TO_MHI_STATE_STR(mhi_cntrl->dev_state),
+		   TO_MHI_EXEC_STR(mhi_cntrl->ee));
+
+	state = mhi_get_mhi_state(mhi_cntrl);
+	ee = mhi_get_exec_env(mhi_cntrl);
+	seq_printf(m, "Device EE: %s state: %s\n", TO_MHI_EXEC_STR(ee),
+		   TO_MHI_STATE_STR(state));
+
+	for (i = 0; regs[i].name; i++) {
+		if (!regs[i].base)
+			continue;
+		ret = mhi_read_reg(mhi_cntrl, regs[i].base, regs[i].offset,
+				   &val);
+		if (ret)
+			continue;
+
+		seq_printf(m, "%s: 0x%x\n", regs[i].name, val);
+	}
+
+	return 0;
+}
+
+static int mhi_debugfs_device_wake_show(struct seq_file *m, void *d)
+{
+	struct mhi_controller *mhi_cntrl = m->private;
+	struct mhi_device *mhi_dev = mhi_cntrl->mhi_dev;
+
+	if (!mhi_is_active(mhi_cntrl)) {
+		seq_puts(m, "Device not ready\n");
+		return -ENODEV;
+	}
+
+	seq_printf(m,
+		   "Wake count: %d\n%s\n", mhi_dev->dev_wake,
+		   "Usage: echo get/put > device_wake to vote/unvote for M0");
+
+	return 0;
+}
+
+static ssize_t mhi_debugfs_device_wake_write(struct file *file,
+					     const char __user *ubuf,
+					     size_t count, loff_t *ppos)
+{
+	struct seq_file	*m = file->private_data;
+	struct mhi_controller *mhi_cntrl = m->private;
+	struct mhi_device *mhi_dev = mhi_cntrl->mhi_dev;
+	char buf[16];
+	int ret = -EINVAL;
+
+	if (copy_from_user(&buf, ubuf, min_t(size_t, sizeof(buf) - 1, count)))
+		return -EFAULT;
+
+	if (!strncmp(buf, "get", 3)) {
+		ret = mhi_device_get_sync(mhi_dev);
+	} else if (!strncmp(buf, "put", 3)) {
+		mhi_device_put(mhi_dev);
+		ret = 0;
+	}
+
+	return ret ? ret : count;
+}
+
+static int mhi_debugfs_timeout_ms_show(struct seq_file *m, void *d)
+{
+	struct mhi_controller *mhi_cntrl = m->private;
+
+	seq_printf(m, "%u ms\n", mhi_cntrl->timeout_ms);
+
+	return 0;
+}
+
+static ssize_t mhi_debugfs_timeout_ms_write(struct file *file,
+					    const char __user *ubuf,
+					    size_t count, loff_t *ppos)
+{
+	struct seq_file	*m = file->private_data;
+	struct mhi_controller *mhi_cntrl = m->private;
+	u32 timeout_ms;
+
+	if (kstrtou32_from_user(ubuf, count, 0, &timeout_ms))
+		return -EINVAL;
+
+	mhi_cntrl->timeout_ms = timeout_ms;
+
+	return count;
+}
+
+static int mhi_debugfs_states_open(struct inode *inode, struct file *fp)
+{
+	return single_open(fp, mhi_debugfs_states_show, inode->i_private);
+}
+
+static int mhi_debugfs_events_open(struct inode *inode, struct file *fp)
+{
+	return single_open(fp, mhi_debugfs_events_show, inode->i_private);
+}
+
+static int mhi_debugfs_channels_open(struct inode *inode, struct file *fp)
+{
+	return single_open(fp, mhi_debugfs_channels_show, inode->i_private);
+}
+
+static int mhi_debugfs_devices_open(struct inode *inode, struct file *fp)
+{
+	return single_open(fp, mhi_debugfs_devices_show, inode->i_private);
+}
+
+static int mhi_debugfs_regdump_open(struct inode *inode, struct file *fp)
+{
+	return single_open(fp, mhi_debugfs_regdump_show, inode->i_private);
+}
+
+static int mhi_debugfs_device_wake_open(struct inode *inode, struct file *fp)
+{
+	return single_open(fp, mhi_debugfs_device_wake_show, inode->i_private);
+}
+
+static int mhi_debugfs_timeout_ms_open(struct inode *inode, struct file *fp)
+{
+	return single_open(fp, mhi_debugfs_timeout_ms_show, inode->i_private);
+}
+
+static const struct file_operations debugfs_states_fops = {
+	.open = mhi_debugfs_states_open,
+	.release = single_release,
+	.read = seq_read,
+};
+
+static const struct file_operations debugfs_events_fops = {
+	.open = mhi_debugfs_events_open,
+	.release = single_release,
+	.read = seq_read,
+};
+
+static const struct file_operations debugfs_channels_fops = {
+	.open = mhi_debugfs_channels_open,
+	.release = single_release,
+	.read = seq_read,
+};
+
+static const struct file_operations debugfs_devices_fops = {
+	.open = mhi_debugfs_devices_open,
+	.release = single_release,
+	.read = seq_read,
+};
+
+static const struct file_operations debugfs_regdump_fops = {
+	.open = mhi_debugfs_regdump_open,
+	.release = single_release,
+	.read = seq_read,
+};
+
+static const struct file_operations debugfs_device_wake_fops = {
+	.open = mhi_debugfs_device_wake_open,
+	.write = mhi_debugfs_device_wake_write,
+	.release = single_release,
+	.read = seq_read,
+};
+
+static const struct file_operations debugfs_timeout_ms_fops = {
+	.open = mhi_debugfs_timeout_ms_open,
+	.write = mhi_debugfs_timeout_ms_write,
+	.release = single_release,
+	.read = seq_read,
+};
+
+static struct dentry *mhi_debugfs_root;
+
+void mhi_create_debugfs(struct mhi_controller *mhi_cntrl)
+{
+	mhi_cntrl->debugfs_dentry =
+			debugfs_create_dir(dev_name(mhi_cntrl->cntrl_dev),
+					   mhi_debugfs_root);
+
+	debugfs_create_file("states", 0444, mhi_cntrl->debugfs_dentry,
+			    mhi_cntrl, &debugfs_states_fops);
+	debugfs_create_file("events", 0444, mhi_cntrl->debugfs_dentry,
+			    mhi_cntrl, &debugfs_events_fops);
+	debugfs_create_file("channels", 0444, mhi_cntrl->debugfs_dentry,
+			    mhi_cntrl, &debugfs_channels_fops);
+	debugfs_create_file("devices", 0444, mhi_cntrl->debugfs_dentry,
+			    mhi_cntrl, &debugfs_devices_fops);
+	debugfs_create_file("regdump", 0444, mhi_cntrl->debugfs_dentry,
+			    mhi_cntrl, &debugfs_regdump_fops);
+	debugfs_create_file("device_wake", 0644, mhi_cntrl->debugfs_dentry,
+			    mhi_cntrl, &debugfs_device_wake_fops);
+	debugfs_create_file("timeout_ms", 0644, mhi_cntrl->debugfs_dentry,
+			    mhi_cntrl, &debugfs_timeout_ms_fops);
+}
+
+void mhi_destroy_debugfs(struct mhi_controller *mhi_cntrl)
+{
+	debugfs_remove_recursive(mhi_cntrl->debugfs_dentry);
+	mhi_cntrl->debugfs_dentry = NULL;
+}
+
+void mhi_debugfs_init(void)
+{
+	mhi_debugfs_root = debugfs_create_dir(mhi_bus_type.name, NULL);
+}
+
+void mhi_debugfs_exit(void)
+{
+	debugfs_remove_recursive(mhi_debugfs_root);
+}
diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
index d23293876be8..61e5885a331a 100644
--- a/drivers/bus/mhi/core/init.c
+++ b/drivers/bus/mhi/core/init.c
@@ -4,6 +4,7 @@
  *
  */
 
+#include <linux/debugfs.h>
 #include <linux/device.h>
 #include <linux/dma-direction.h>
 #include <linux/dma-mapping.h>
@@ -915,6 +916,8 @@ int mhi_register_controller(struct mhi_controller *mhi_cntrl,
 
 	mhi_cntrl->mhi_dev = mhi_dev;
 
+	mhi_create_debugfs(mhi_cntrl);
+
 	return 0;
 
 error_add_dev:
@@ -937,6 +940,8 @@ void mhi_unregister_controller(struct mhi_controller *mhi_cntrl)
 	struct mhi_chan *mhi_chan = mhi_cntrl->mhi_chan;
 	unsigned int i;
 
+	mhi_destroy_debugfs(mhi_cntrl);
+
 	kfree(mhi_cntrl->mhi_cmd);
 	kfree(mhi_cntrl->mhi_event);
 
@@ -1300,11 +1305,13 @@ struct bus_type mhi_bus_type = {
 
 static int __init mhi_init(void)
 {
+	mhi_debugfs_init();
 	return bus_register(&mhi_bus_type);
 }
 
 static void __exit mhi_exit(void)
 {
+	mhi_debugfs_exit();
 	bus_unregister(&mhi_bus_type);
 }
 
diff --git a/drivers/bus/mhi/core/internal.h b/drivers/bus/mhi/core/internal.h
index 5a81a428c4aa..7989269ddd96 100644
--- a/drivers/bus/mhi/core/internal.h
+++ b/drivers/bus/mhi/core/internal.h
@@ -570,6 +570,30 @@ struct mhi_chan {
 /* Default MHI timeout */
 #define MHI_TIMEOUT_MS (1000)
 
+/* debugfs related functions */
+#ifdef CONFIG_MHI_BUS_DEBUG
+void mhi_create_debugfs(struct mhi_controller *mhi_cntrl);
+void mhi_destroy_debugfs(struct mhi_controller *mhi_cntrl);
+void mhi_debugfs_init(void);
+void mhi_debugfs_exit(void);
+#else
+static inline void mhi_create_debugfs(struct mhi_controller *mhi_cntrl)
+{
+}
+
+static inline void mhi_destroy_debugfs(struct mhi_controller *mhi_cntrl)
+{
+}
+
+static inline void mhi_debugfs_init(void)
+{
+}
+
+static inline void mhi_debugfs_exit(void)
+{
+}
+#endif
+
 struct mhi_device *mhi_alloc_device(struct mhi_controller *mhi_cntrl);
 
 int mhi_destroy_device(struct device *dev, void *data);
diff --git a/include/linux/mhi.h b/include/linux/mhi.h
index 008b8f6fa9ff..fb45a0ff9aa3 100644
--- a/include/linux/mhi.h
+++ b/include/linux/mhi.h
@@ -291,6 +291,7 @@ struct mhi_controller_config {
  * @cntrl_dev: Pointer to the struct device of physical bus acting as the MHI
  *            controller (required)
  * @mhi_dev: MHI device instance for the controller
+ * @debugfs_dentry: MHI controller debugfs directory
  * @regs: Base address of MHI MMIO register space (required)
  * @bhi: Points to base of MHI BHI register space
  * @bhie: Points to base of MHI BHIe register space
@@ -370,6 +371,7 @@ struct mhi_controller_config {
 struct mhi_controller {
 	struct device *cntrl_dev;
 	struct mhi_device *mhi_dev;
+	struct dentry *debugfs_dentry;
 	void __iomem *regs;
 	void __iomem *bhi;
 	void __iomem *bhie;
-- 
2.17.1

[PATCH 15/18] bus: mhi: core: Introduce sysfs entries for MHI

[Manivannan Sadhasivam]

From: Bhaumik Bhatt <bbhatt@codeaurora.org>

Introduce sysfs entries to enable userspace clients the ability to read
the serial number and the OEM PK Hash values obtained from BHI. OEMs
need to read these device-specific hardware information values through
userspace for factory testing purposes and cannot be exposed via degbufs
as it may remain disabled for performance reasons. Also, update the
documentation for ABI to include these entries.

Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 Documentation/ABI/stable/sysfs-bus-mhi | 21 ++++++++++
 MAINTAINERS                            |  1 +
 drivers/bus/mhi/core/init.c            | 53 ++++++++++++++++++++++++++
 3 files changed, 75 insertions(+)
 create mode 100644 Documentation/ABI/stable/sysfs-bus-mhi

diff --git a/Documentation/ABI/stable/sysfs-bus-mhi b/Documentation/ABI/stable/sysfs-bus-mhi
new file mode 100644
index 000000000000..ecfe7662f8d0
--- /dev/null
+++ b/Documentation/ABI/stable/sysfs-bus-mhi
@@ -0,0 +1,21 @@
+What:		/sys/bus/mhi/devices/.../serialnumber
+Date:		Sept 2020
+KernelVersion:	5.10
+Contact:	Bhaumik Bhatt <bbhatt@codeaurora.org>
+Description:	The file holds the serial number of the client device obtained
+		using a BHI (Boot Host Interface) register read after at least
+		one attempt to power up the device has been done. If read
+		without having the device power on at least once, the file will
+		read all 0's.
+Users:		Any userspace application or clients interested in device info.
+
+What:		/sys/bus/mhi/devices/.../oem_pk_hash
+Date:		Sept 2020
+KernelVersion:	5.10
+Contact:	Bhaumik Bhatt <bbhatt@codeaurora.org>
+Description:	The file holds the OEM PK Hash value of the endpoint device
+		obtained using a BHI (Boot Host Interface) register read after
+		at least one attempt to power up the device has been done. If
+		read without having the device power on at least once, the file
+		will read all 0's.
+Users:		Any userspace application or clients interested in device info.
diff --git a/MAINTAINERS b/MAINTAINERS
index deaafb617361..11e7be9b9163 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -11323,6 +11323,7 @@ M:	Hemant Kumar <hemantk@codeaurora.org>
 L:	linux-arm-msm@vger.kernel.org
 S:	Maintained
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/mani/mhi.git
+F:	Documentation/ABI/stable/sysfs-bus-mhi
 F:	Documentation/mhi/
 F:	drivers/bus/mhi/
 F:	include/linux/mhi.h
diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
index 61e5885a331a..1b4161eaf0d8 100644
--- a/drivers/bus/mhi/core/init.c
+++ b/drivers/bus/mhi/core/init.c
@@ -76,6 +76,56 @@ const char *to_mhi_pm_state_str(enum mhi_pm_state state)
 	return mhi_pm_state_str[index];
 }
 
+static ssize_t serial_number_show(struct device *dev,
+				  struct device_attribute *attr,
+				  char *buf)
+{
+	struct mhi_device *mhi_dev = to_mhi_device(dev);
+	struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
+
+	return snprintf(buf, PAGE_SIZE, "Serial Number: %u\n",
+			mhi_cntrl->serial_number);
+}
+static DEVICE_ATTR_RO(serial_number);
+
+static ssize_t oem_pk_hash_show(struct device *dev,
+				struct device_attribute *attr,
+				char *buf)
+{
+	struct mhi_device *mhi_dev = to_mhi_device(dev);
+	struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
+	int i, cnt = 0;
+
+	for (i = 0; i < ARRAY_SIZE(mhi_cntrl->oem_pk_hash); i++)
+		cnt += snprintf(buf + cnt, PAGE_SIZE - cnt,
+				"OEMPKHASH[%d]: 0x%x\n", i,
+				mhi_cntrl->oem_pk_hash[i]);
+
+	return cnt;
+}
+static DEVICE_ATTR_RO(oem_pk_hash);
+
+static struct attribute *mhi_sysfs_attrs[] = {
+	&dev_attr_serial_number.attr,
+	&dev_attr_oem_pk_hash.attr,
+	NULL,
+};
+
+static const struct attribute_group mhi_sysfs_group = {
+	.attrs = mhi_sysfs_attrs,
+};
+
+static int mhi_create_sysfs(struct mhi_controller *mhi_cntrl)
+{
+	return sysfs_create_group(&mhi_cntrl->mhi_dev->dev.kobj,
+				  &mhi_sysfs_group);
+}
+
+static void mhi_destroy_sysfs(struct mhi_controller *mhi_cntrl)
+{
+	sysfs_remove_group(&mhi_cntrl->mhi_dev->dev.kobj, &mhi_sysfs_group);
+}
+
 /* MHI protocol requires the transfer ring to be aligned with ring length */
 static int mhi_alloc_aligned_ring(struct mhi_controller *mhi_cntrl,
 				  struct mhi_ring *ring,
@@ -917,6 +967,8 @@ int mhi_register_controller(struct mhi_controller *mhi_cntrl,
 	mhi_cntrl->mhi_dev = mhi_dev;
 
 	mhi_create_debugfs(mhi_cntrl);
+	if (mhi_create_sysfs(mhi_cntrl))
+		dev_err(mhi_cntrl->cntrl_dev, "Failed to create sysfs entries\n");
 
 	return 0;
 
@@ -940,6 +992,7 @@ void mhi_unregister_controller(struct mhi_controller *mhi_cntrl)
 	struct mhi_chan *mhi_chan = mhi_cntrl->mhi_chan;
 	unsigned int i;
 
+	mhi_destroy_sysfs(mhi_cntrl);
 	mhi_destroy_debugfs(mhi_cntrl);
 
 	kfree(mhi_cntrl->mhi_cmd);
-- 
2.17.1

Re: [PATCH 15/18] bus: mhi: core: Introduce sysfs entries for MHI

[Greg KH]

On Mon, Sep 21, 2020 at 09:38:12PM +0530, Manivannan Sadhasivam wrote:
> From: Bhaumik Bhatt <bbhatt@codeaurora.org>
> 
> Introduce sysfs entries to enable userspace clients the ability to read
> the serial number and the OEM PK Hash values obtained from BHI. OEMs
> need to read these device-specific hardware information values through
> userspace for factory testing purposes and cannot be exposed via degbufs
> as it may remain disabled for performance reasons. Also, update the
> documentation for ABI to include these entries.
> 
> Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
> Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> ---
>  Documentation/ABI/stable/sysfs-bus-mhi | 21 ++++++++++
>  MAINTAINERS                            |  1 +
>  drivers/bus/mhi/core/init.c            | 53 ++++++++++++++++++++++++++
>  3 files changed, 75 insertions(+)
>  create mode 100644 Documentation/ABI/stable/sysfs-bus-mhi
> 
> diff --git a/Documentation/ABI/stable/sysfs-bus-mhi b/Documentation/ABI/stable/sysfs-bus-mhi
> new file mode 100644
> index 000000000000..ecfe7662f8d0
> --- /dev/null
> +++ b/Documentation/ABI/stable/sysfs-bus-mhi
> @@ -0,0 +1,21 @@
> +What:		/sys/bus/mhi/devices/.../serialnumber
> +Date:		Sept 2020
> +KernelVersion:	5.10
> +Contact:	Bhaumik Bhatt <bbhatt@codeaurora.org>
> +Description:	The file holds the serial number of the client device obtained
> +		using a BHI (Boot Host Interface) register read after at least
> +		one attempt to power up the device has been done. If read
> +		without having the device power on at least once, the file will
> +		read all 0's.
> +Users:		Any userspace application or clients interested in device info.
> +
> +What:		/sys/bus/mhi/devices/.../oem_pk_hash
> +Date:		Sept 2020
> +KernelVersion:	5.10
> +Contact:	Bhaumik Bhatt <bbhatt@codeaurora.org>
> +Description:	The file holds the OEM PK Hash value of the endpoint device
> +		obtained using a BHI (Boot Host Interface) register read after
> +		at least one attempt to power up the device has been done. If
> +		read without having the device power on at least once, the file
> +		will read all 0's.
> +Users:		Any userspace application or clients interested in device info.
> diff --git a/MAINTAINERS b/MAINTAINERS
> index deaafb617361..11e7be9b9163 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -11323,6 +11323,7 @@ M:	Hemant Kumar <hemantk@codeaurora.org>
>  L:	linux-arm-msm@vger.kernel.org
>  S:	Maintained
>  T:	git git://git.kernel.org/pub/scm/linux/kernel/git/mani/mhi.git
> +F:	Documentation/ABI/stable/sysfs-bus-mhi
>  F:	Documentation/mhi/
>  F:	drivers/bus/mhi/
>  F:	include/linux/mhi.h
> diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
> index 61e5885a331a..1b4161eaf0d8 100644
> --- a/drivers/bus/mhi/core/init.c
> +++ b/drivers/bus/mhi/core/init.c
> @@ -76,6 +76,56 @@ const char *to_mhi_pm_state_str(enum mhi_pm_state state)
>  	return mhi_pm_state_str[index];
>  }
>  
> +static ssize_t serial_number_show(struct device *dev,
> +				  struct device_attribute *attr,
> +				  char *buf)
> +{
> +	struct mhi_device *mhi_dev = to_mhi_device(dev);
> +	struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
> +
> +	return snprintf(buf, PAGE_SIZE, "Serial Number: %u\n",
> +			mhi_cntrl->serial_number);
> +}
> +static DEVICE_ATTR_RO(serial_number);
> +
> +static ssize_t oem_pk_hash_show(struct device *dev,
> +				struct device_attribute *attr,
> +				char *buf)
> +{
> +	struct mhi_device *mhi_dev = to_mhi_device(dev);
> +	struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
> +	int i, cnt = 0;
> +
> +	for (i = 0; i < ARRAY_SIZE(mhi_cntrl->oem_pk_hash); i++)
> +		cnt += snprintf(buf + cnt, PAGE_SIZE - cnt,
> +				"OEMPKHASH[%d]: 0x%x\n", i,
> +				mhi_cntrl->oem_pk_hash[i]);
> +
> +	return cnt;
> +}
> +static DEVICE_ATTR_RO(oem_pk_hash);
> +
> +static struct attribute *mhi_sysfs_attrs[] = {
> +	&dev_attr_serial_number.attr,
> +	&dev_attr_oem_pk_hash.attr,
> +	NULL,
> +};
> +
> +static const struct attribute_group mhi_sysfs_group = {
> +	.attrs = mhi_sysfs_attrs,
> +};
> +
> +static int mhi_create_sysfs(struct mhi_controller *mhi_cntrl)
> +{
> +	return sysfs_create_group(&mhi_cntrl->mhi_dev->dev.kobj,
> +				  &mhi_sysfs_group);

You should never have to call a sysfs_* function from a driver or bus
code, that implies something is wrong :)

Just set the sysfs attributes to be the default groups for your
bus/device/whatever-you-have-here and then the driver core will properly
manage the creation and removal of these files, in a race-free manner.

As it is, I think this is racy and will cause userspace confusion, but I
haven't looked for sure, as you should use the api that guarantees it is
safe...

thanks,

greg k-h

Re: [PATCH 15/18] bus: mhi: core: Introduce sysfs entries for MHI

[Manivannan Sadhasivam]

On Sun, Sep 27, 2020 at 12:26:59PM +0200, Greg KH wrote:
> On Mon, Sep 21, 2020 at 09:38:12PM +0530, Manivannan Sadhasivam wrote:
> > From: Bhaumik Bhatt <bbhatt@codeaurora.org>
> > 
> > Introduce sysfs entries to enable userspace clients the ability to read
> > the serial number and the OEM PK Hash values obtained from BHI. OEMs
> > need to read these device-specific hardware information values through
> > userspace for factory testing purposes and cannot be exposed via degbufs
> > as it may remain disabled for performance reasons. Also, update the
> > documentation for ABI to include these entries.
> > 
> > Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
> > Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> > ---
> >  Documentation/ABI/stable/sysfs-bus-mhi | 21 ++++++++++
> >  MAINTAINERS                            |  1 +
> >  drivers/bus/mhi/core/init.c            | 53 ++++++++++++++++++++++++++
> >  3 files changed, 75 insertions(+)
> >  create mode 100644 Documentation/ABI/stable/sysfs-bus-mhi
> > 
> > diff --git a/Documentation/ABI/stable/sysfs-bus-mhi b/Documentation/ABI/stable/sysfs-bus-mhi
> > new file mode 100644
> > index 000000000000..ecfe7662f8d0
> > --- /dev/null
> > +++ b/Documentation/ABI/stable/sysfs-bus-mhi
> > @@ -0,0 +1,21 @@
> > +What:		/sys/bus/mhi/devices/.../serialnumber
> > +Date:		Sept 2020
> > +KernelVersion:	5.10
> > +Contact:	Bhaumik Bhatt <bbhatt@codeaurora.org>
> > +Description:	The file holds the serial number of the client device obtained
> > +		using a BHI (Boot Host Interface) register read after at least
> > +		one attempt to power up the device has been done. If read
> > +		without having the device power on at least once, the file will
> > +		read all 0's.
> > +Users:		Any userspace application or clients interested in device info.
> > +
> > +What:		/sys/bus/mhi/devices/.../oem_pk_hash
> > +Date:		Sept 2020
> > +KernelVersion:	5.10
> > +Contact:	Bhaumik Bhatt <bbhatt@codeaurora.org>
> > +Description:	The file holds the OEM PK Hash value of the endpoint device
> > +		obtained using a BHI (Boot Host Interface) register read after
> > +		at least one attempt to power up the device has been done. If
> > +		read without having the device power on at least once, the file
> > +		will read all 0's.
> > +Users:		Any userspace application or clients interested in device info.
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index deaafb617361..11e7be9b9163 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -11323,6 +11323,7 @@ M:	Hemant Kumar <hemantk@codeaurora.org>
> >  L:	linux-arm-msm@vger.kernel.org
> >  S:	Maintained
> >  T:	git git://git.kernel.org/pub/scm/linux/kernel/git/mani/mhi.git
> > +F:	Documentation/ABI/stable/sysfs-bus-mhi
> >  F:	Documentation/mhi/
> >  F:	drivers/bus/mhi/
> >  F:	include/linux/mhi.h
> > diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
> > index 61e5885a331a..1b4161eaf0d8 100644
> > --- a/drivers/bus/mhi/core/init.c
> > +++ b/drivers/bus/mhi/core/init.c
> > @@ -76,6 +76,56 @@ const char *to_mhi_pm_state_str(enum mhi_pm_state state)
> >  	return mhi_pm_state_str[index];
> >  }
> >  

[...]

> > +static int mhi_create_sysfs(struct mhi_controller *mhi_cntrl)
> > +{
> > +	return sysfs_create_group(&mhi_cntrl->mhi_dev->dev.kobj,
> > +				  &mhi_sysfs_group);
> 
> You should never have to call a sysfs_* function from a driver or bus
> code, that implies something is wrong :)
> 

Hmm. I think the inspiration is drawn from an old bus driver :(
Will submit a patch later to fix it!

> Just set the sysfs attributes to be the default groups for your
> bus/device/whatever-you-have-here and then the driver core will properly
> manage the creation and removal of these files, in a race-free manner.
> 
> As it is, I think this is racy and will cause userspace confusion, but I
> haven't looked for sure, as you should use the api that guarantees it is
> safe...
> 

Okay. Will use the dev_groups callback to manage the sysfs attributes.

Thanks,
Mani

> thanks,
> 
> greg k-h

[PATCH 16/18] bus: mhi: core: Allow shared IRQ for event rings

[Manivannan Sadhasivam]

From: Loic Poulain <loic.poulain@linaro.org>

There is no requirement for using a dedicated IRQ per event ring.
Some systems does not support multiple MSI vectors (e.g. intel
without CONFIG_IRQ_REMAP), In that case the MHI controller can
configure all the event rings to use the same interrupt (as fallback).

Allow this by removing the nr_irqs = ev_ring test and add extra check
in the irq_setup function.

Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/bus/mhi/core/init.c | 7 +++++++
 drivers/bus/mhi/core/pm.c   | 2 +-
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
index 1b4161eaf0d8..049a10fa42d7 100644
--- a/drivers/bus/mhi/core/init.c
+++ b/drivers/bus/mhi/core/init.c
@@ -176,6 +176,13 @@ int mhi_init_irq_setup(struct mhi_controller *mhi_cntrl)
 		if (mhi_event->offload_ev)
 			continue;
 
+		if (mhi_event->irq >= mhi_cntrl->nr_irqs) {
+			dev_err(dev, "irq %d not available for event ring\n",
+				mhi_event->irq);
+			ret = -EINVAL;
+			goto error_request;
+		}
+
 		ret = request_irq(mhi_cntrl->irq[mhi_event->irq],
 				  mhi_irq_handler,
 				  IRQF_SHARED | IRQF_NO_SUSPEND,
diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c
index ce4d969818b4..3de7b1639ec6 100644
--- a/drivers/bus/mhi/core/pm.c
+++ b/drivers/bus/mhi/core/pm.c
@@ -918,7 +918,7 @@ int mhi_async_power_up(struct mhi_controller *mhi_cntrl)
 
 	dev_info(dev, "Requested to power ON\n");
 
-	if (mhi_cntrl->nr_irqs < mhi_cntrl->total_ev_rings)
+	if (mhi_cntrl->nr_irqs < 1)
 		return -EINVAL;
 
 	/* Supply default wake routines if not provided by controller driver */
-- 
2.17.1

[PATCH 17/18] bus: mhi: Remove unused nr_irqs_req variable

[Manivannan Sadhasivam]

From: Loic Poulain <loic.poulain@linaro.org>

nr_irqs_req is unused in MHI stack.

Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/bus/mhi/core/init.c | 3 ---
 include/linux/mhi.h         | 2 --
 2 files changed, 5 deletions(-)

diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
index 049a10fa42d7..799111baceba 100644
--- a/drivers/bus/mhi/core/init.c
+++ b/drivers/bus/mhi/core/init.c
@@ -694,9 +694,6 @@ static int parse_ev_cfg(struct mhi_controller *mhi_cntrl,
 		mhi_event++;
 	}
 
-	/* We need IRQ for each event ring + additional one for BHI */
-	mhi_cntrl->nr_irqs_req = mhi_cntrl->total_ev_rings + 1;
-
 	return 0;
 
 error_ev_cfg:
diff --git a/include/linux/mhi.h b/include/linux/mhi.h
index fb45a0ff9aa3..d4841e5a5f45 100644
--- a/include/linux/mhi.h
+++ b/include/linux/mhi.h
@@ -312,7 +312,6 @@ struct mhi_controller_config {
  * @total_ev_rings: Total # of event rings allocated
  * @hw_ev_rings: Number of hardware event rings
  * @sw_ev_rings: Number of software event rings
- * @nr_irqs_req: Number of IRQs required to operate (optional)
  * @nr_irqs: Number of IRQ allocated by bus master (required)
  * @family_number: MHI controller family number
  * @device_number: MHI controller device number
@@ -393,7 +392,6 @@ struct mhi_controller {
 	u32 total_ev_rings;
 	u32 hw_ev_rings;
 	u32 sw_ev_rings;
-	u32 nr_irqs_req;
 	u32 nr_irqs;
 	u32 family_number;
 	u32 device_number;
-- 
2.17.1

[PATCH 18/18] bus: mhi: core: Fix the building of MHI module

[Manivannan Sadhasivam]

The Kbuild rule to build MHI should use the append operator. This fixes
the below warning reported by Kbuild test bot.

WARNING: modpost: missing MODULE_LICENSE() in
drivers/bus/mhi/core/main.o
WARNING: modpost: missing MODULE_LICENSE() in drivers/bus/mhi/core/pm.o
WARNING: modpost: missing MODULE_LICENSE() in
drivers/bus/mhi/core/boot.o

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/bus/mhi/core/Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/bus/mhi/core/Makefile b/drivers/bus/mhi/core/Makefile
index 12c57ab3724c..c3feb4130aa3 100644
--- a/drivers/bus/mhi/core/Makefile
+++ b/drivers/bus/mhi/core/Makefile
@@ -1,4 +1,4 @@
-obj-$(CONFIG_MHI_BUS) := mhi.o
+obj-$(CONFIG_MHI_BUS) += mhi.o
 
 mhi-y := init.o main.o pm.o boot.o
 mhi-$(CONFIG_MHI_BUS_DEBUG) += debugfs.o
-- 
2.17.1

Re: [PATCH 18/18] bus: mhi: core: Fix the building of MHI module

[Greg KH]

On Mon, Sep 21, 2020 at 09:38:15PM +0530, Manivannan Sadhasivam wrote:
> The Kbuild rule to build MHI should use the append operator. This fixes
> the below warning reported by Kbuild test bot.
> 
> WARNING: modpost: missing MODULE_LICENSE() in
> drivers/bus/mhi/core/main.o
> WARNING: modpost: missing MODULE_LICENSE() in drivers/bus/mhi/core/pm.o
> WARNING: modpost: missing MODULE_LICENSE() in
> drivers/bus/mhi/core/boot.o
> 
> Reported-by: kernel test robot <lkp@intel.com>
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

What commit caused this problem?  Can you add a Fixes: line for it?

thanks,

greg k-h

Re: [PATCH 18/18] bus: mhi: core: Fix the building of MHI module

[Manivannan Sadhasivam]

On Sun, Sep 27, 2020 at 12:22:33PM +0200, Greg KH wrote:
> On Mon, Sep 21, 2020 at 09:38:15PM +0530, Manivannan Sadhasivam wrote:
> > The Kbuild rule to build MHI should use the append operator. This fixes
> > the below warning reported by Kbuild test bot.
> > 
> > WARNING: modpost: missing MODULE_LICENSE() in
> > drivers/bus/mhi/core/main.o
> > WARNING: modpost: missing MODULE_LICENSE() in drivers/bus/mhi/core/pm.o
> > WARNING: modpost: missing MODULE_LICENSE() in
> > drivers/bus/mhi/core/boot.o
> > 
> > Reported-by: kernel test robot <lkp@intel.com>
> > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> 
> What commit caused this problem?  Can you add a Fixes: line for it?
> 

Sure, will add the fixes tag!

Thanks,
Mani

> thanks,
> 
> greg k-h