[PATCH v6 0/9] Add support for MHI Endpoint function driver

[PATCH v6 0/9] Add support for MHI Endpoint function driver

[Manivannan Sadhasivam]

Hello,

This series adds support for Modem Host Interface (MHI) Endpoint function
driver and few updates to the PCI endpoint core.

MHI
===

MHI is the communication protocol used by the host machines to control and
communicate with the Qualcomm modems/WLAN devices over any high speed physical
bus like PCIe. In Linux kernel, MHI is modeled as a bus driver [1] and there
are two instances of MHI used in a typical setup.

1. MHI host - MHI implementation for the host machines like x86/ARM64.
2. MHI Endpoint - MHI implementation for the endpoint devices like modems.

MHI EPF
=======

The MHI Endpoint function driver (MHI EPF) is used on the MHI endpoint devices
like modems. The MHI EPF driver sits in between the PCIe EP and MHI EP bus and
carries out all of the PCIe related activities like BAR config, PCIe Event
handling, MMIO read/write etc,... for the MHI EP bus.

Below is the simple representation of the setup:


                 +----------------------------------------------------+
                 |                  Endpoint CPU                      |                   
                 |                                                    |
+------------+   |   +------------+   +-----------+   +-----------+   |
|            |   |   |            |   |           |   |           |   |
|            |   |   |   MHI EP   |   |           |   |           |   | PCIe Bus
|  Modem DSP +---+---+    Bus     +---+  MHI EPF  +---+  PCIe EP  +---+---------
|            |   |   |            |   |           |   |           |   |
|            |   |   |            |   |           |   |           |   |
+------------+   |   +------------+   +-----------+   +-----------+   |
                 |                                                    |
                 |                                                    |
                 +----------------------------------------------------+

The data packets will be read from the Modem DSP by the MHI stack and will be
transmitted to the host machine over PCIe bus with the help of MHI EPF driver.

Test setup
==========

This series has been tested on Snapdragon X55 modem a.k.a SDX55 connected to
the ARM64 host machine.

Thanks,
Mani

[1] https://www.kernel.org/doc/html/latest/mhi/mhi.html

Changes in v6:

* Moved the alloc/map and unmap/free code to separate helper functions and used
  them to avoid code duplication in epf driver.
* Removed superfluous WARN_ON_ONCE() from epf driver.

Changes in v5:

* Moved the PCI EPF driver match logic to pci_epf_match_id() function and used
  that to get the matched driver ID for passing to driver probe instead of
  storing the id during match.
* Added a patch to fix the missing documentation about MSI/MSI-X start vector.
* Addressed the review comments on the MHI EPF driver. Most notably, got rid of
  local variable for tracking MHI registration and used the mhi_dev pointer.
  Also, modified the MSI vector increment comment to make it clear.
* Added a patch for adding MHI EPF driver to MAINTAINERS file

Changes in v4:

* Collected review tag from Kishon
* Changed the IP_SW0 channel numbers as per latest MHI spec

Changes in v3:

* Fixed the probe function of EPF_VNTB driver

Changes in v2:

* Rebased on top of v6.3-rc1
* Switched to the new callback interface for passing events from EPC to EPF
* Dropped one patch related to notifier

Manivannan Sadhasivam (9):
  PCI: endpoint: Add missing documentation about the MSI/MSI-X range
  PCI: endpoint: Pass EPF device ID to the probe function
  PCI: endpoint: Return error if EPC is started/stopped multiple times
  PCI: endpoint: Add linkdown notifier support
  PCI: endpoint: Add BME notifier support
  PCI: qcom-ep: Add support for Link down notification
  PCI: qcom-ep: Add support for BME notification
  PCI: endpoint: Add PCI Endpoint function driver for MHI bus
  MAINTAINERS: Add PCI MHI endpoint function driver under MHI bus

 MAINTAINERS                                   |   1 +
 drivers/pci/controller/dwc/pcie-qcom-ep.c     |   2 +
 drivers/pci/endpoint/functions/Kconfig        |  10 +
 drivers/pci/endpoint/functions/Makefile       |   1 +
 drivers/pci/endpoint/functions/pci-epf-mhi.c  | 465 ++++++++++++++++++
 drivers/pci/endpoint/functions/pci-epf-ntb.c  |   3 +-
 drivers/pci/endpoint/functions/pci-epf-test.c |   2 +-
 drivers/pci/endpoint/functions/pci-epf-vntb.c |   2 +-
 drivers/pci/endpoint/pci-ep-cfs.c             |   3 +
 drivers/pci/endpoint/pci-epc-core.c           |  56 ++-
 drivers/pci/endpoint/pci-epf-core.c           |  18 +-
 include/linux/pci-epc.h                       |   2 +
 include/linux/pci-epf.h                       |   8 +-
 13 files changed, 560 insertions(+), 13 deletions(-)
 create mode 100644 drivers/pci/endpoint/functions/pci-epf-mhi.c

-- 
2.25.1

[PATCH v6 1/9] PCI: endpoint: Add missing documentation about the MSI/MSI-X range

[Manivannan Sadhasivam]

Both pci_epc_raise_irq() and pci_epc_map_msi_irq() APIs expects the
MSI/MSI-X vectors to start from 1 but it is not documented. Add the
range info to the kdoc of the APIs to make it clear.

Fixes: 5e8cb4033807 ("PCI: endpoint: Add EP core layer to enable EP controller and EP functions")
Fixes: 87d5972e476f ("PCI: endpoint: Add pci_epc_ops to map MSI IRQ")
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/pci/endpoint/pci-epc-core.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
index 46c9a5c3ca14..0cf602c83d4a 100644
--- a/drivers/pci/endpoint/pci-epc-core.c
+++ b/drivers/pci/endpoint/pci-epc-core.c
@@ -213,7 +213,7 @@ EXPORT_SYMBOL_GPL(pci_epc_start);
  * @func_no: the physical endpoint function number in the EPC device
  * @vfunc_no: the virtual endpoint function number in the physical function
  * @type: specify the type of interrupt; legacy, MSI or MSI-X
- * @interrupt_num: the MSI or MSI-X interrupt number
+ * @interrupt_num: the MSI or MSI-X interrupt number with range (1-N)
  *
  * Invoke to raise an legacy, MSI or MSI-X interrupt
  */
@@ -246,7 +246,7 @@ EXPORT_SYMBOL_GPL(pci_epc_raise_irq);
  * @func_no: the physical endpoint function number in the EPC device
  * @vfunc_no: the virtual endpoint function number in the physical function
  * @phys_addr: the physical address of the outbound region
- * @interrupt_num: the MSI interrupt number
+ * @interrupt_num: the MSI interrupt number with range (1-N)
  * @entry_size: Size of Outbound address region for each interrupt
  * @msi_data: the data that should be written in order to raise MSI interrupt
  *            with interrupt number as 'interrupt num'
-- 
2.25.1

[PATCH v6 2/9] PCI: endpoint: Pass EPF device ID to the probe function

[Manivannan Sadhasivam]

Currently, the EPF probe function doesn't get the device ID argument needed
to correctly identify the device table ID of the EPF device.

When multiple entries are added to the "struct pci_epf_device_id" table,
the probe function needs to identify the correct one. This is achieved by
modifying the pci_epf_match_id() function to return the match ID pointer
and passing it to the driver's probe function.

pci_epf_device_match() function can return bool based on the return value
of pci_epf_match_id().

Reviewed-by: Kishon Vijay Abraham I <kishon@kernel.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/pci/endpoint/functions/pci-epf-ntb.c  |  3 ++-
 drivers/pci/endpoint/functions/pci-epf-test.c |  2 +-
 drivers/pci/endpoint/functions/pci-epf-vntb.c |  2 +-
 drivers/pci/endpoint/pci-epf-core.c           | 18 +++++++++++-------
 include/linux/pci-epf.h                       |  4 +++-
 5 files changed, 18 insertions(+), 11 deletions(-)

diff --git a/drivers/pci/endpoint/functions/pci-epf-ntb.c b/drivers/pci/endpoint/functions/pci-epf-ntb.c
index 9a00448c7e61..980b4ecf19a2 100644
--- a/drivers/pci/endpoint/functions/pci-epf-ntb.c
+++ b/drivers/pci/endpoint/functions/pci-epf-ntb.c
@@ -2075,11 +2075,12 @@ static struct config_group *epf_ntb_add_cfs(struct pci_epf *epf,
 /**
  * epf_ntb_probe() - Probe NTB function driver
  * @epf: NTB endpoint function device
+ * @id: NTB endpoint function device ID
  *
  * Probe NTB function driver when endpoint function bus detects a NTB
  * endpoint function.
  */
-static int epf_ntb_probe(struct pci_epf *epf)
+static int epf_ntb_probe(struct pci_epf *epf, const struct pci_epf_device_id *id)
 {
 	struct epf_ntb *ntb;
 	struct device *dev;
diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
index 0f9d2ec822ac..d5fcc78a5b73 100644
--- a/drivers/pci/endpoint/functions/pci-epf-test.c
+++ b/drivers/pci/endpoint/functions/pci-epf-test.c
@@ -980,7 +980,7 @@ static const struct pci_epf_device_id pci_epf_test_ids[] = {
 	{},
 };
 
-static int pci_epf_test_probe(struct pci_epf *epf)
+static int pci_epf_test_probe(struct pci_epf *epf, const struct pci_epf_device_id *id)
 {
 	struct pci_epf_test *epf_test;
 	struct device *dev = &epf->dev;
diff --git a/drivers/pci/endpoint/functions/pci-epf-vntb.c b/drivers/pci/endpoint/functions/pci-epf-vntb.c
index b7c7a8af99f4..122eb7a12028 100644
--- a/drivers/pci/endpoint/functions/pci-epf-vntb.c
+++ b/drivers/pci/endpoint/functions/pci-epf-vntb.c
@@ -1401,7 +1401,7 @@ static struct pci_epf_ops epf_ntb_ops = {
  *
  * Returns: Zero for success, or an error code in case of failure
  */
-static int epf_ntb_probe(struct pci_epf *epf)
+static int epf_ntb_probe(struct pci_epf *epf, const struct pci_epf_device_id *id)
 {
 	struct epf_ntb *ntb;
 	struct device *dev;
diff --git a/drivers/pci/endpoint/pci-epf-core.c b/drivers/pci/endpoint/pci-epf-core.c
index 2036e38be093..ea6e0aef0bb3 100644
--- a/drivers/pci/endpoint/pci-epf-core.c
+++ b/drivers/pci/endpoint/pci-epf-core.c
@@ -493,16 +493,16 @@ static const struct device_type pci_epf_type = {
 	.release	= pci_epf_dev_release,
 };
 
-static int
-pci_epf_match_id(const struct pci_epf_device_id *id, const struct pci_epf *epf)
+static const struct pci_epf_device_id
+*pci_epf_match_id(const struct pci_epf_device_id *id, const struct pci_epf *epf)
 {
 	while (id->name[0]) {
 		if (strcmp(epf->name, id->name) == 0)
-			return true;
+			return id;
 		id++;
 	}
 
-	return false;
+	return NULL;
 }
 
 static int pci_epf_device_match(struct device *dev, struct device_driver *drv)
@@ -510,8 +510,12 @@ static int pci_epf_device_match(struct device *dev, struct device_driver *drv)
 	struct pci_epf *epf = to_pci_epf(dev);
 	struct pci_epf_driver *driver = to_pci_epf_driver(drv);
 
-	if (driver->id_table)
-		return pci_epf_match_id(driver->id_table, epf);
+	if (driver->id_table) {
+		if (pci_epf_match_id(driver->id_table, epf))
+			return true;
+		else
+			return false;
+	}
 
 	return !strcmp(epf->name, drv->name);
 }
@@ -526,7 +530,7 @@ static int pci_epf_device_probe(struct device *dev)
 
 	epf->driver = driver;
 
-	return driver->probe(epf);
+	return driver->probe(epf, pci_epf_match_id(driver->id_table, epf));
 }
 
 static void pci_epf_device_remove(struct device *dev)
diff --git a/include/linux/pci-epf.h b/include/linux/pci-epf.h
index a215dc8ce693..bc613f0df7e3 100644
--- a/include/linux/pci-epf.h
+++ b/include/linux/pci-epf.h
@@ -89,7 +89,7 @@ struct pci_epc_event_ops {
  * @id_table: identifies EPF devices for probing
  */
 struct pci_epf_driver {
-	int	(*probe)(struct pci_epf *epf);
+	int	(*probe)(struct pci_epf *epf, const struct pci_epf_device_id *id);
 	void	(*remove)(struct pci_epf *epf);
 
 	struct device_driver	driver;
@@ -131,6 +131,7 @@ struct pci_epf_bar {
  * @epc: the EPC device to which this EPF device is bound
  * @epf_pf: the physical EPF device to which this virtual EPF device is bound
  * @driver: the EPF driver to which this EPF device is bound
+ * @id: Pointer to the EPF device ID
  * @list: to add pci_epf as a list of PCI endpoint functions to pci_epc
  * @lock: mutex to protect pci_epf_ops
  * @sec_epc: the secondary EPC device to which this EPF device is bound
@@ -158,6 +159,7 @@ struct pci_epf {
 	struct pci_epc		*epc;
 	struct pci_epf		*epf_pf;
 	struct pci_epf_driver	*driver;
+	const struct pci_epf_device_id *id;
 	struct list_head	list;
 	/* mutex to protect against concurrent access of pci_epf_ops */
 	struct mutex		lock;
-- 
2.25.1

Re: [PATCH v6 2/9] PCI: endpoint: Pass EPF device ID to the probe function

[Damien Le Moal]

On 6/2/23 20:47, Manivannan Sadhasivam wrote:
> Currently, the EPF probe function doesn't get the device ID argument needed
> to correctly identify the device table ID of the EPF device.
> 
> When multiple entries are added to the "struct pci_epf_device_id" table,
> the probe function needs to identify the correct one. This is achieved by
> modifying the pci_epf_match_id() function to return the match ID pointer
> and passing it to the driver's probe function.
> 
> pci_epf_device_match() function can return bool based on the return value
> of pci_epf_match_id().
> 
> Reviewed-by: Kishon Vijay Abraham I <kishon@kernel.org>
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

[...]

>  static int pci_epf_device_match(struct device *dev, struct device_driver *drv)
> @@ -510,8 +510,12 @@ static int pci_epf_device_match(struct device *dev, struct device_driver *drv)
>  	struct pci_epf *epf = to_pci_epf(dev);
>  	struct pci_epf_driver *driver = to_pci_epf_driver(drv);
>  
> -	if (driver->id_table)
> -		return pci_epf_match_id(driver->id_table, epf);
> +	if (driver->id_table) {
> +		if (pci_epf_match_id(driver->id_table, epf))
> +			return true;
> +		else
> +			return false;

You prefer keeping this pattern ?

return pci_epf_match_id(driver->id_table, epf) != NULL;

is no much nicer !

Anyway:

Reviewed-by: Damien Le Moal <dlemoal@kernel.org>

-- 
Damien Le Moal
Western Digital Research

Re: [PATCH v6 2/9] PCI: endpoint: Pass EPF device ID to the probe function

[Lorenzo Pieralisi]

On Fri, Jun 02, 2023 at 09:13:25PM +0900, Damien Le Moal wrote:
> On 6/2/23 20:47, Manivannan Sadhasivam wrote:
> > Currently, the EPF probe function doesn't get the device ID argument needed
> > to correctly identify the device table ID of the EPF device.
> > 
> > When multiple entries are added to the "struct pci_epf_device_id" table,
> > the probe function needs to identify the correct one. This is achieved by
> > modifying the pci_epf_match_id() function to return the match ID pointer
> > and passing it to the driver's probe function.
> > 
> > pci_epf_device_match() function can return bool based on the return value
> > of pci_epf_match_id().
> > 
> > Reviewed-by: Kishon Vijay Abraham I <kishon@kernel.org>
> > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> 
> [...]
> 
> >  static int pci_epf_device_match(struct device *dev, struct device_driver *drv)
> > @@ -510,8 +510,12 @@ static int pci_epf_device_match(struct device *dev, struct device_driver *drv)
> >  	struct pci_epf *epf = to_pci_epf(dev);
> >  	struct pci_epf_driver *driver = to_pci_epf_driver(drv);
> >  
> > -	if (driver->id_table)
> > -		return pci_epf_match_id(driver->id_table, epf);
> > +	if (driver->id_table) {
> > +		if (pci_epf_match_id(driver->id_table, epf))
> > +			return true;
> > +		else
> > +			return false;
> 
> You prefer keeping this pattern ?
> 
> return pci_epf_match_id(driver->id_table, epf) != NULL;
> 
> is no much nicer !

s/no/so

Yes it is, I can change it myself to spare Mani few cycles.

Lorenzo

> 
> Anyway:
> 
> Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
> 
> -- 
> Damien Le Moal
> Western Digital Research
> 

Re: [PATCH v6 2/9] PCI: endpoint: Pass EPF device ID to the probe function

[Manivannan Sadhasivam]

On Mon, Jun 05, 2023 at 03:08:33PM +0200, Lorenzo Pieralisi wrote:
> On Fri, Jun 02, 2023 at 09:13:25PM +0900, Damien Le Moal wrote:
> > On 6/2/23 20:47, Manivannan Sadhasivam wrote:
> > > Currently, the EPF probe function doesn't get the device ID argument needed
> > > to correctly identify the device table ID of the EPF device.
> > > 
> > > When multiple entries are added to the "struct pci_epf_device_id" table,
> > > the probe function needs to identify the correct one. This is achieved by
> > > modifying the pci_epf_match_id() function to return the match ID pointer
> > > and passing it to the driver's probe function.
> > > 
> > > pci_epf_device_match() function can return bool based on the return value
> > > of pci_epf_match_id().
> > > 
> > > Reviewed-by: Kishon Vijay Abraham I <kishon@kernel.org>
> > > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> > 
> > [...]
> > 
> > >  static int pci_epf_device_match(struct device *dev, struct device_driver *drv)
> > > @@ -510,8 +510,12 @@ static int pci_epf_device_match(struct device *dev, struct device_driver *drv)
> > >  	struct pci_epf *epf = to_pci_epf(dev);
> > >  	struct pci_epf_driver *driver = to_pci_epf_driver(drv);
> > >  
> > > -	if (driver->id_table)
> > > -		return pci_epf_match_id(driver->id_table, epf);
> > > +	if (driver->id_table) {
> > > +		if (pci_epf_match_id(driver->id_table, epf))
> > > +			return true;
> > > +		else
> > > +			return false;
> > 
> > You prefer keeping this pattern ?
> > 
> > return pci_epf_match_id(driver->id_table, epf) != NULL;
> > 
> > is no much nicer !
> 
> s/no/so
> 
> Yes it is, I can change it myself to spare Mani few cycles.
> 

Please do!

- Mani

> Lorenzo
> 
> > 
> > Anyway:
> > 
> > Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
> > 
> > -- 
> > Damien Le Moal
> > Western Digital Research
> > 

-- 
மணிவண்ணன் சதாசிவம்

Re: [PATCH v6 2/9] PCI: endpoint: Pass EPF device ID to the probe function

[Lorenzo Pieralisi]

On Fri, Jun 02, 2023 at 05:17:49PM +0530, Manivannan Sadhasivam wrote:
> Currently, the EPF probe function doesn't get the device ID argument needed
> to correctly identify the device table ID of the EPF device.
> 
> When multiple entries are added to the "struct pci_epf_device_id" table,
> the probe function needs to identify the correct one. This is achieved by
> modifying the pci_epf_match_id() function to return the match ID pointer
> and passing it to the driver's probe function.
> 
> pci_epf_device_match() function can return bool based on the return value
> of pci_epf_match_id().
> 
> Reviewed-by: Kishon Vijay Abraham I <kishon@kernel.org>
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> ---
>  drivers/pci/endpoint/functions/pci-epf-ntb.c  |  3 ++-
>  drivers/pci/endpoint/functions/pci-epf-test.c |  2 +-
>  drivers/pci/endpoint/functions/pci-epf-vntb.c |  2 +-
>  drivers/pci/endpoint/pci-epf-core.c           | 18 +++++++++++-------
>  include/linux/pci-epf.h                       |  4 +++-
>  5 files changed, 18 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/pci/endpoint/functions/pci-epf-ntb.c b/drivers/pci/endpoint/functions/pci-epf-ntb.c
> index 9a00448c7e61..980b4ecf19a2 100644
> --- a/drivers/pci/endpoint/functions/pci-epf-ntb.c
> +++ b/drivers/pci/endpoint/functions/pci-epf-ntb.c
> @@ -2075,11 +2075,12 @@ static struct config_group *epf_ntb_add_cfs(struct pci_epf *epf,
>  /**
>   * epf_ntb_probe() - Probe NTB function driver
>   * @epf: NTB endpoint function device
> + * @id: NTB endpoint function device ID
>   *
>   * Probe NTB function driver when endpoint function bus detects a NTB
>   * endpoint function.
>   */
> -static int epf_ntb_probe(struct pci_epf *epf)
> +static int epf_ntb_probe(struct pci_epf *epf, const struct pci_epf_device_id *id)
>  {
>  	struct epf_ntb *ntb;
>  	struct device *dev;
> diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
> index 0f9d2ec822ac..d5fcc78a5b73 100644
> --- a/drivers/pci/endpoint/functions/pci-epf-test.c
> +++ b/drivers/pci/endpoint/functions/pci-epf-test.c
> @@ -980,7 +980,7 @@ static const struct pci_epf_device_id pci_epf_test_ids[] = {
>  	{},
>  };
>  
> -static int pci_epf_test_probe(struct pci_epf *epf)
> +static int pci_epf_test_probe(struct pci_epf *epf, const struct pci_epf_device_id *id)
>  {
>  	struct pci_epf_test *epf_test;
>  	struct device *dev = &epf->dev;
> diff --git a/drivers/pci/endpoint/functions/pci-epf-vntb.c b/drivers/pci/endpoint/functions/pci-epf-vntb.c
> index b7c7a8af99f4..122eb7a12028 100644
> --- a/drivers/pci/endpoint/functions/pci-epf-vntb.c
> +++ b/drivers/pci/endpoint/functions/pci-epf-vntb.c
> @@ -1401,7 +1401,7 @@ static struct pci_epf_ops epf_ntb_ops = {
>   *
>   * Returns: Zero for success, or an error code in case of failure
>   */
> -static int epf_ntb_probe(struct pci_epf *epf)
> +static int epf_ntb_probe(struct pci_epf *epf, const struct pci_epf_device_id *id)
>  {
>  	struct epf_ntb *ntb;
>  	struct device *dev;
> diff --git a/drivers/pci/endpoint/pci-epf-core.c b/drivers/pci/endpoint/pci-epf-core.c
> index 2036e38be093..ea6e0aef0bb3 100644
> --- a/drivers/pci/endpoint/pci-epf-core.c
> +++ b/drivers/pci/endpoint/pci-epf-core.c
> @@ -493,16 +493,16 @@ static const struct device_type pci_epf_type = {
>  	.release	= pci_epf_dev_release,
>  };
>  
> -static int
> -pci_epf_match_id(const struct pci_epf_device_id *id, const struct pci_epf *epf)
> +static const struct pci_epf_device_id
> +*pci_epf_match_id(const struct pci_epf_device_id *id, const struct pci_epf *epf)
>  {
>  	while (id->name[0]) {
>  		if (strcmp(epf->name, id->name) == 0)
> -			return true;
> +			return id;
>  		id++;
>  	}
>  
> -	return false;
> +	return NULL;
>  }
>  
>  static int pci_epf_device_match(struct device *dev, struct device_driver *drv)
> @@ -510,8 +510,12 @@ static int pci_epf_device_match(struct device *dev, struct device_driver *drv)
>  	struct pci_epf *epf = to_pci_epf(dev);
>  	struct pci_epf_driver *driver = to_pci_epf_driver(drv);
>  
> -	if (driver->id_table)
> -		return pci_epf_match_id(driver->id_table, epf);
> +	if (driver->id_table) {
> +		if (pci_epf_match_id(driver->id_table, epf))
> +			return true;
> +		else
> +			return false;
> +	}
>  
>  	return !strcmp(epf->name, drv->name);
>  }
> @@ -526,7 +530,7 @@ static int pci_epf_device_probe(struct device *dev)
>  
>  	epf->driver = driver;
>  
> -	return driver->probe(epf);
> +	return driver->probe(epf, pci_epf_match_id(driver->id_table, epf));

I don't think we should do it this way. If we are probing a driver that
means that we have got a driver that matches a device id. The device id
is a property of the device, there is no reason why we should pass it
to the probe function, it has got to be stored somewhere at device
creation stage (well, not in the match function - since that's what
we changed), probe() should retrieve it from the device structure.

Thanks,
Lorenzo

>  }
>  
>  static void pci_epf_device_remove(struct device *dev)
> diff --git a/include/linux/pci-epf.h b/include/linux/pci-epf.h
> index a215dc8ce693..bc613f0df7e3 100644
> --- a/include/linux/pci-epf.h
> +++ b/include/linux/pci-epf.h
> @@ -89,7 +89,7 @@ struct pci_epc_event_ops {
>   * @id_table: identifies EPF devices for probing
>   */
>  struct pci_epf_driver {
> -	int	(*probe)(struct pci_epf *epf);
> +	int	(*probe)(struct pci_epf *epf, const struct pci_epf_device_id *id);
>  	void	(*remove)(struct pci_epf *epf);
>  
>  	struct device_driver	driver;
> @@ -131,6 +131,7 @@ struct pci_epf_bar {
>   * @epc: the EPC device to which this EPF device is bound
>   * @epf_pf: the physical EPF device to which this virtual EPF device is bound
>   * @driver: the EPF driver to which this EPF device is bound
> + * @id: Pointer to the EPF device ID
>   * @list: to add pci_epf as a list of PCI endpoint functions to pci_epc
>   * @lock: mutex to protect pci_epf_ops
>   * @sec_epc: the secondary EPC device to which this EPF device is bound
> @@ -158,6 +159,7 @@ struct pci_epf {
>  	struct pci_epc		*epc;
>  	struct pci_epf		*epf_pf;
>  	struct pci_epf_driver	*driver;
> +	const struct pci_epf_device_id *id;
>  	struct list_head	list;
>  	/* mutex to protect against concurrent access of pci_epf_ops */
>  	struct mutex		lock;
> -- 
> 2.25.1
> 

Re: [PATCH v6 2/9] PCI: endpoint: Pass EPF device ID to the probe function

[Manivannan Sadhasivam]

On Mon, Jun 05, 2023 at 11:27:09AM +0200, Lorenzo Pieralisi wrote:
> On Fri, Jun 02, 2023 at 05:17:49PM +0530, Manivannan Sadhasivam wrote:
> > Currently, the EPF probe function doesn't get the device ID argument needed
> > to correctly identify the device table ID of the EPF device.
> > 
> > When multiple entries are added to the "struct pci_epf_device_id" table,
> > the probe function needs to identify the correct one. This is achieved by
> > modifying the pci_epf_match_id() function to return the match ID pointer
> > and passing it to the driver's probe function.
> > 
> > pci_epf_device_match() function can return bool based on the return value
> > of pci_epf_match_id().
> > 
> > Reviewed-by: Kishon Vijay Abraham I <kishon@kernel.org>
> > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> > ---
> >  drivers/pci/endpoint/functions/pci-epf-ntb.c  |  3 ++-
> >  drivers/pci/endpoint/functions/pci-epf-test.c |  2 +-
> >  drivers/pci/endpoint/functions/pci-epf-vntb.c |  2 +-
> >  drivers/pci/endpoint/pci-epf-core.c           | 18 +++++++++++-------
> >  include/linux/pci-epf.h                       |  4 +++-
> >  5 files changed, 18 insertions(+), 11 deletions(-)
> > 
> > diff --git a/drivers/pci/endpoint/functions/pci-epf-ntb.c b/drivers/pci/endpoint/functions/pci-epf-ntb.c
> > index 9a00448c7e61..980b4ecf19a2 100644
> > --- a/drivers/pci/endpoint/functions/pci-epf-ntb.c
> > +++ b/drivers/pci/endpoint/functions/pci-epf-ntb.c
> > @@ -2075,11 +2075,12 @@ static struct config_group *epf_ntb_add_cfs(struct pci_epf *epf,
> >  /**
> >   * epf_ntb_probe() - Probe NTB function driver
> >   * @epf: NTB endpoint function device
> > + * @id: NTB endpoint function device ID
> >   *
> >   * Probe NTB function driver when endpoint function bus detects a NTB
> >   * endpoint function.
> >   */
> > -static int epf_ntb_probe(struct pci_epf *epf)
> > +static int epf_ntb_probe(struct pci_epf *epf, const struct pci_epf_device_id *id)
> >  {
> >  	struct epf_ntb *ntb;
> >  	struct device *dev;
> > diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
> > index 0f9d2ec822ac..d5fcc78a5b73 100644
> > --- a/drivers/pci/endpoint/functions/pci-epf-test.c
> > +++ b/drivers/pci/endpoint/functions/pci-epf-test.c
> > @@ -980,7 +980,7 @@ static const struct pci_epf_device_id pci_epf_test_ids[] = {
> >  	{},
> >  };
> >  
> > -static int pci_epf_test_probe(struct pci_epf *epf)
> > +static int pci_epf_test_probe(struct pci_epf *epf, const struct pci_epf_device_id *id)
> >  {
> >  	struct pci_epf_test *epf_test;
> >  	struct device *dev = &epf->dev;
> > diff --git a/drivers/pci/endpoint/functions/pci-epf-vntb.c b/drivers/pci/endpoint/functions/pci-epf-vntb.c
> > index b7c7a8af99f4..122eb7a12028 100644
> > --- a/drivers/pci/endpoint/functions/pci-epf-vntb.c
> > +++ b/drivers/pci/endpoint/functions/pci-epf-vntb.c
> > @@ -1401,7 +1401,7 @@ static struct pci_epf_ops epf_ntb_ops = {
> >   *
> >   * Returns: Zero for success, or an error code in case of failure
> >   */
> > -static int epf_ntb_probe(struct pci_epf *epf)
> > +static int epf_ntb_probe(struct pci_epf *epf, const struct pci_epf_device_id *id)
> >  {
> >  	struct epf_ntb *ntb;
> >  	struct device *dev;
> > diff --git a/drivers/pci/endpoint/pci-epf-core.c b/drivers/pci/endpoint/pci-epf-core.c
> > index 2036e38be093..ea6e0aef0bb3 100644
> > --- a/drivers/pci/endpoint/pci-epf-core.c
> > +++ b/drivers/pci/endpoint/pci-epf-core.c
> > @@ -493,16 +493,16 @@ static const struct device_type pci_epf_type = {
> >  	.release	= pci_epf_dev_release,
> >  };
> >  
> > -static int
> > -pci_epf_match_id(const struct pci_epf_device_id *id, const struct pci_epf *epf)
> > +static const struct pci_epf_device_id
> > +*pci_epf_match_id(const struct pci_epf_device_id *id, const struct pci_epf *epf)
> >  {
> >  	while (id->name[0]) {
> >  		if (strcmp(epf->name, id->name) == 0)
> > -			return true;
> > +			return id;
> >  		id++;
> >  	}
> >  
> > -	return false;
> > +	return NULL;
> >  }
> >  
> >  static int pci_epf_device_match(struct device *dev, struct device_driver *drv)
> > @@ -510,8 +510,12 @@ static int pci_epf_device_match(struct device *dev, struct device_driver *drv)
> >  	struct pci_epf *epf = to_pci_epf(dev);
> >  	struct pci_epf_driver *driver = to_pci_epf_driver(drv);
> >  
> > -	if (driver->id_table)
> > -		return pci_epf_match_id(driver->id_table, epf);
> > +	if (driver->id_table) {
> > +		if (pci_epf_match_id(driver->id_table, epf))
> > +			return true;
> > +		else
> > +			return false;
> > +	}
> >  
> >  	return !strcmp(epf->name, drv->name);
> >  }
> > @@ -526,7 +530,7 @@ static int pci_epf_device_probe(struct device *dev)
> >  
> >  	epf->driver = driver;
> >  
> > -	return driver->probe(epf);
> > +	return driver->probe(epf, pci_epf_match_id(driver->id_table, epf));
> 
> I don't think we should do it this way. If we are probing a driver that
> means that we have got a driver that matches a device id. The device id
> is a property of the device, there is no reason why we should pass it
> to the probe function, it has got to be stored somewhere at device
> creation stage (well, not in the match function - since that's what
> we changed), probe() should retrieve it from the device structure.
> 

Device id defined by the drivers will only be known during the match() stage as
that's when the drivers are queried for match of the device. During device
creation stage, there is no way for the EPF core to fetch the ids.

And, passing id during probe() is not new. For most of the non-platform devices,
the bus driver will pass the id. The PCI core itself is doing the same for the
client drivers as well and I'd like to keep it same for EPF also:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/linux/pci.h#n921

- Mani

> Thanks,
> Lorenzo
> 
> >  }
> >  
> >  static void pci_epf_device_remove(struct device *dev)
> > diff --git a/include/linux/pci-epf.h b/include/linux/pci-epf.h
> > index a215dc8ce693..bc613f0df7e3 100644
> > --- a/include/linux/pci-epf.h
> > +++ b/include/linux/pci-epf.h
> > @@ -89,7 +89,7 @@ struct pci_epc_event_ops {
> >   * @id_table: identifies EPF devices for probing
> >   */
> >  struct pci_epf_driver {
> > -	int	(*probe)(struct pci_epf *epf);
> > +	int	(*probe)(struct pci_epf *epf, const struct pci_epf_device_id *id);
> >  	void	(*remove)(struct pci_epf *epf);
> >  
> >  	struct device_driver	driver;
> > @@ -131,6 +131,7 @@ struct pci_epf_bar {
> >   * @epc: the EPC device to which this EPF device is bound
> >   * @epf_pf: the physical EPF device to which this virtual EPF device is bound
> >   * @driver: the EPF driver to which this EPF device is bound
> > + * @id: Pointer to the EPF device ID
> >   * @list: to add pci_epf as a list of PCI endpoint functions to pci_epc
> >   * @lock: mutex to protect pci_epf_ops
> >   * @sec_epc: the secondary EPC device to which this EPF device is bound
> > @@ -158,6 +159,7 @@ struct pci_epf {
> >  	struct pci_epc		*epc;
> >  	struct pci_epf		*epf_pf;
> >  	struct pci_epf_driver	*driver;
> > +	const struct pci_epf_device_id *id;
> >  	struct list_head	list;
> >  	/* mutex to protect against concurrent access of pci_epf_ops */
> >  	struct mutex		lock;
> > -- 
> > 2.25.1
> > 

-- 
மணிவண்ணன் சதாசிவம்

Re: [PATCH v6 2/9] PCI: endpoint: Pass EPF device ID to the probe function

[Lorenzo Pieralisi]

On Mon, Jun 05, 2023 at 05:27:46PM +0530, Manivannan Sadhasivam wrote:
> On Mon, Jun 05, 2023 at 11:27:09AM +0200, Lorenzo Pieralisi wrote:
> > On Fri, Jun 02, 2023 at 05:17:49PM +0530, Manivannan Sadhasivam wrote:
> > > Currently, the EPF probe function doesn't get the device ID argument needed
> > > to correctly identify the device table ID of the EPF device.
> > > 
> > > When multiple entries are added to the "struct pci_epf_device_id" table,
> > > the probe function needs to identify the correct one. This is achieved by
> > > modifying the pci_epf_match_id() function to return the match ID pointer
> > > and passing it to the driver's probe function.
> > > 
> > > pci_epf_device_match() function can return bool based on the return value
> > > of pci_epf_match_id().
> > > 
> > > Reviewed-by: Kishon Vijay Abraham I <kishon@kernel.org>
> > > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> > > ---
> > >  drivers/pci/endpoint/functions/pci-epf-ntb.c  |  3 ++-
> > >  drivers/pci/endpoint/functions/pci-epf-test.c |  2 +-
> > >  drivers/pci/endpoint/functions/pci-epf-vntb.c |  2 +-
> > >  drivers/pci/endpoint/pci-epf-core.c           | 18 +++++++++++-------
> > >  include/linux/pci-epf.h                       |  4 +++-
> > >  5 files changed, 18 insertions(+), 11 deletions(-)
> > > 
> > > diff --git a/drivers/pci/endpoint/functions/pci-epf-ntb.c b/drivers/pci/endpoint/functions/pci-epf-ntb.c
> > > index 9a00448c7e61..980b4ecf19a2 100644
> > > --- a/drivers/pci/endpoint/functions/pci-epf-ntb.c
> > > +++ b/drivers/pci/endpoint/functions/pci-epf-ntb.c
> > > @@ -2075,11 +2075,12 @@ static struct config_group *epf_ntb_add_cfs(struct pci_epf *epf,
> > >  /**
> > >   * epf_ntb_probe() - Probe NTB function driver
> > >   * @epf: NTB endpoint function device
> > > + * @id: NTB endpoint function device ID
> > >   *
> > >   * Probe NTB function driver when endpoint function bus detects a NTB
> > >   * endpoint function.
> > >   */
> > > -static int epf_ntb_probe(struct pci_epf *epf)
> > > +static int epf_ntb_probe(struct pci_epf *epf, const struct pci_epf_device_id *id)
> > >  {
> > >  	struct epf_ntb *ntb;
> > >  	struct device *dev;
> > > diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
> > > index 0f9d2ec822ac..d5fcc78a5b73 100644
> > > --- a/drivers/pci/endpoint/functions/pci-epf-test.c
> > > +++ b/drivers/pci/endpoint/functions/pci-epf-test.c
> > > @@ -980,7 +980,7 @@ static const struct pci_epf_device_id pci_epf_test_ids[] = {
> > >  	{},
> > >  };
> > >  
> > > -static int pci_epf_test_probe(struct pci_epf *epf)
> > > +static int pci_epf_test_probe(struct pci_epf *epf, const struct pci_epf_device_id *id)
> > >  {
> > >  	struct pci_epf_test *epf_test;
> > >  	struct device *dev = &epf->dev;
> > > diff --git a/drivers/pci/endpoint/functions/pci-epf-vntb.c b/drivers/pci/endpoint/functions/pci-epf-vntb.c
> > > index b7c7a8af99f4..122eb7a12028 100644
> > > --- a/drivers/pci/endpoint/functions/pci-epf-vntb.c
> > > +++ b/drivers/pci/endpoint/functions/pci-epf-vntb.c
> > > @@ -1401,7 +1401,7 @@ static struct pci_epf_ops epf_ntb_ops = {
> > >   *
> > >   * Returns: Zero for success, or an error code in case of failure
> > >   */
> > > -static int epf_ntb_probe(struct pci_epf *epf)
> > > +static int epf_ntb_probe(struct pci_epf *epf, const struct pci_epf_device_id *id)
> > >  {
> > >  	struct epf_ntb *ntb;
> > >  	struct device *dev;
> > > diff --git a/drivers/pci/endpoint/pci-epf-core.c b/drivers/pci/endpoint/pci-epf-core.c
> > > index 2036e38be093..ea6e0aef0bb3 100644
> > > --- a/drivers/pci/endpoint/pci-epf-core.c
> > > +++ b/drivers/pci/endpoint/pci-epf-core.c
> > > @@ -493,16 +493,16 @@ static const struct device_type pci_epf_type = {
> > >  	.release	= pci_epf_dev_release,
> > >  };
> > >  
> > > -static int
> > > -pci_epf_match_id(const struct pci_epf_device_id *id, const struct pci_epf *epf)
> > > +static const struct pci_epf_device_id
> > > +*pci_epf_match_id(const struct pci_epf_device_id *id, const struct pci_epf *epf)
> > >  {
> > >  	while (id->name[0]) {
> > >  		if (strcmp(epf->name, id->name) == 0)
> > > -			return true;
> > > +			return id;
> > >  		id++;
> > >  	}
> > >  
> > > -	return false;
> > > +	return NULL;
> > >  }
> > >  
> > >  static int pci_epf_device_match(struct device *dev, struct device_driver *drv)
> > > @@ -510,8 +510,12 @@ static int pci_epf_device_match(struct device *dev, struct device_driver *drv)
> > >  	struct pci_epf *epf = to_pci_epf(dev);
> > >  	struct pci_epf_driver *driver = to_pci_epf_driver(drv);
> > >  
> > > -	if (driver->id_table)
> > > -		return pci_epf_match_id(driver->id_table, epf);
> > > +	if (driver->id_table) {
> > > +		if (pci_epf_match_id(driver->id_table, epf))
> > > +			return true;
> > > +		else
> > > +			return false;
> > > +	}
> > >  
> > >  	return !strcmp(epf->name, drv->name);
> > >  }
> > > @@ -526,7 +530,7 @@ static int pci_epf_device_probe(struct device *dev)
> > >  
> > >  	epf->driver = driver;
> > >  
> > > -	return driver->probe(epf);
> > > +	return driver->probe(epf, pci_epf_match_id(driver->id_table, epf));
> > 
> > I don't think we should do it this way. If we are probing a driver that
> > means that we have got a driver that matches a device id. The device id
> > is a property of the device, there is no reason why we should pass it
> > to the probe function, it has got to be stored somewhere at device
> > creation stage (well, not in the match function - since that's what
> > we changed), probe() should retrieve it from the device structure.
> > 
> 
> Device id defined by the drivers will only be known during the match() stage as
> that's when the drivers are queried for match of the device. During device
> creation stage, there is no way for the EPF core to fetch the ids.
> 
> And, passing id during probe() is not new. For most of the non-platform devices,
> the bus driver will pass the id. The PCI core itself is doing the same for the
> client drivers as well and I'd like to keep it same for EPF also:
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/linux/pci.h#n921

Right - I mixed things up (driver->probe() vs bus->probe), apologies,
it makes sense.

Lorenzo

> 
> - Mani
> 
> > Thanks,
> > Lorenzo
> > 
> > >  }
> > >  
> > >  static void pci_epf_device_remove(struct device *dev)
> > > diff --git a/include/linux/pci-epf.h b/include/linux/pci-epf.h
> > > index a215dc8ce693..bc613f0df7e3 100644
> > > --- a/include/linux/pci-epf.h
> > > +++ b/include/linux/pci-epf.h
> > > @@ -89,7 +89,7 @@ struct pci_epc_event_ops {
> > >   * @id_table: identifies EPF devices for probing
> > >   */
> > >  struct pci_epf_driver {
> > > -	int	(*probe)(struct pci_epf *epf);
> > > +	int	(*probe)(struct pci_epf *epf, const struct pci_epf_device_id *id);
> > >  	void	(*remove)(struct pci_epf *epf);
> > >  
> > >  	struct device_driver	driver;
> > > @@ -131,6 +131,7 @@ struct pci_epf_bar {
> > >   * @epc: the EPC device to which this EPF device is bound
> > >   * @epf_pf: the physical EPF device to which this virtual EPF device is bound
> > >   * @driver: the EPF driver to which this EPF device is bound
> > > + * @id: Pointer to the EPF device ID
> > >   * @list: to add pci_epf as a list of PCI endpoint functions to pci_epc
> > >   * @lock: mutex to protect pci_epf_ops
> > >   * @sec_epc: the secondary EPC device to which this EPF device is bound
> > > @@ -158,6 +159,7 @@ struct pci_epf {
> > >  	struct pci_epc		*epc;
> > >  	struct pci_epf		*epf_pf;
> > >  	struct pci_epf_driver	*driver;
> > > +	const struct pci_epf_device_id *id;
> > >  	struct list_head	list;
> > >  	/* mutex to protect against concurrent access of pci_epf_ops */
> > >  	struct mutex		lock;
> > > -- 
> > > 2.25.1
> > > 
> 
> -- 
> மணிவண்ணன் சதாசிவம்

Re: [PATCH v6 2/9] PCI: endpoint: Pass EPF device ID to the probe function

[Bjorn Helgaas]

On Fri, Jun 02, 2023 at 05:17:49PM +0530, Manivannan Sadhasivam wrote:
> Currently, the EPF probe function doesn't get the device ID argument needed
> to correctly identify the device table ID of the EPF device.
> ...

> +++ b/drivers/pci/endpoint/functions/pci-epf-ntb.c
> @@ -2075,11 +2075,12 @@ static struct config_group *epf_ntb_add_cfs(struct pci_epf *epf,
>  /**
>   * epf_ntb_probe() - Probe NTB function driver
>   * @epf: NTB endpoint function device
> + * @id: NTB endpoint function device ID
>   *
>   * Probe NTB function driver when endpoint function bus detects a NTB
>   * endpoint function.
>   */
> -static int epf_ntb_probe(struct pci_epf *epf)
> +static int epf_ntb_probe(struct pci_epf *epf, const struct pci_epf_device_id *id)
> ...

> +++ b/drivers/pci/endpoint/functions/pci-epf-vntb.c
> @@ -1401,7 +1401,7 @@ static struct pci_epf_ops epf_ntb_ops = {

>   *
>   * Returns: Zero for success, or an error code in case of failure
>   */
> -static int epf_ntb_probe(struct pci_epf *epf)
> +static int epf_ntb_probe(struct pci_epf *epf, const struct pci_epf_device_id *id)

I updated the pci/endpoint branch to add kernel-doc for the new "id",
same as you did in pci-epf-ntb.c.

Just FYI, Lorenzo & Krzysztof -- hopefully there are no more updates
before the merge window, but if you do add anything to this branch,
update it first.

Bjorn

[PATCH v6 3/9] PCI: endpoint: Return error if EPC is started/stopped multiple times

[Manivannan Sadhasivam]

When the EPC is started or stopped multiple times from configfs, just
return -EALREADY. There is no need to call the EPC start/stop functions
in those cases.

Reviewed-by: Kishon Vijay Abraham I <kishon@kernel.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/pci/endpoint/pci-ep-cfs.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/pci/endpoint/pci-ep-cfs.c b/drivers/pci/endpoint/pci-ep-cfs.c
index 4b8ac0ac84d5..7e0e430e4ceb 100644
--- a/drivers/pci/endpoint/pci-ep-cfs.c
+++ b/drivers/pci/endpoint/pci-ep-cfs.c
@@ -178,6 +178,9 @@ static ssize_t pci_epc_start_store(struct config_item *item, const char *page,
 	if (kstrtobool(page, &start) < 0)
 		return -EINVAL;
 
+	if (start == epc_group->start)
+		return -EALREADY;
+
 	if (!start) {
 		pci_epc_stop(epc);
 		epc_group->start = 0;
-- 
2.25.1

Re: [PATCH v6 3/9] PCI: endpoint: Return error if EPC is started/stopped multiple times

[Damien Le Moal]

On 6/2/23 20:47, Manivannan Sadhasivam wrote:
> When the EPC is started or stopped multiple times from configfs, just
> return -EALREADY. There is no need to call the EPC start/stop functions
> in those cases.
> 
> Reviewed-by: Kishon Vijay Abraham I <kishon@kernel.org>
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

Reviewed-by: Damien Le Moal <dlemoal@kernel.org>

-- 
Damien Le Moal
Western Digital Research

[PATCH v6 4/9] PCI: endpoint: Add linkdown notifier support

[Manivannan Sadhasivam]

Add support to notify the EPF device about the linkdown event from the
EPC device.

Reviewed-by: Kishon Vijay Abraham I <kishon@kernel.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/pci/endpoint/pci-epc-core.c | 26 ++++++++++++++++++++++++++
 include/linux/pci-epc.h             |  1 +
 include/linux/pci-epf.h             |  2 ++
 3 files changed, 29 insertions(+)

diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
index 0cf602c83d4a..e0570b52698d 100644
--- a/drivers/pci/endpoint/pci-epc-core.c
+++ b/drivers/pci/endpoint/pci-epc-core.c
@@ -706,6 +706,32 @@ void pci_epc_linkup(struct pci_epc *epc)
 }
 EXPORT_SYMBOL_GPL(pci_epc_linkup);
 
+/**
+ * pci_epc_linkdown() - Notify the EPF device that EPC device has dropped the
+ *			connection with the Root Complex.
+ * @epc: the EPC device which has dropped the link with the host
+ *
+ * Invoke to Notify the EPF device that the EPC device has dropped the
+ * connection with the Root Complex.
+ */
+void pci_epc_linkdown(struct pci_epc *epc)
+{
+	struct pci_epf *epf;
+
+	if (!epc || IS_ERR(epc))
+		return;
+
+	mutex_lock(&epc->list_lock);
+	list_for_each_entry(epf, &epc->pci_epf, list) {
+		mutex_lock(&epf->lock);
+		if (epf->event_ops && epf->event_ops->link_down)
+			epf->event_ops->link_down(epf);
+		mutex_unlock(&epf->lock);
+	}
+	mutex_unlock(&epc->list_lock);
+}
+EXPORT_SYMBOL_GPL(pci_epc_linkdown);
+
 /**
  * pci_epc_init_notify() - Notify the EPF device that EPC device's core
  *			   initialization is completed.
diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h
index 301bb0e53707..63a6cc5e5282 100644
--- a/include/linux/pci-epc.h
+++ b/include/linux/pci-epc.h
@@ -203,6 +203,7 @@ void pci_epc_destroy(struct pci_epc *epc);
 int pci_epc_add_epf(struct pci_epc *epc, struct pci_epf *epf,
 		    enum pci_epc_interface_type type);
 void pci_epc_linkup(struct pci_epc *epc);
+void pci_epc_linkdown(struct pci_epc *epc);
 void pci_epc_init_notify(struct pci_epc *epc);
 void pci_epc_remove_epf(struct pci_epc *epc, struct pci_epf *epf,
 			enum pci_epc_interface_type type);
diff --git a/include/linux/pci-epf.h b/include/linux/pci-epf.h
index bc613f0df7e3..f8e5a63d0c83 100644
--- a/include/linux/pci-epf.h
+++ b/include/linux/pci-epf.h
@@ -71,10 +71,12 @@ struct pci_epf_ops {
  * struct pci_epf_event_ops - Callbacks for capturing the EPC events
  * @core_init: Callback for the EPC initialization complete event
  * @link_up: Callback for the EPC link up event
+ * @link_down: Callback for the EPC link down event
  */
 struct pci_epc_event_ops {
 	int (*core_init)(struct pci_epf *epf);
 	int (*link_up)(struct pci_epf *epf);
+	int (*link_down)(struct pci_epf *epf);
 };
 
 /**
-- 
2.25.1

[PATCH v6 5/9] PCI: endpoint: Add BME notifier support

[Manivannan Sadhasivam]

Add support to notify the EPF device about the Bus Master Enable (BME)
event received by the EPC device from the Root complex.

Reviewed-by: Kishon Vijay Abraham I <kishon@kernel.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/pci/endpoint/pci-epc-core.c | 26 ++++++++++++++++++++++++++
 include/linux/pci-epc.h             |  1 +
 include/linux/pci-epf.h             |  2 ++
 3 files changed, 29 insertions(+)

diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
index e0570b52698d..6c54fa5684d2 100644
--- a/drivers/pci/endpoint/pci-epc-core.c
+++ b/drivers/pci/endpoint/pci-epc-core.c
@@ -758,6 +758,32 @@ void pci_epc_init_notify(struct pci_epc *epc)
 }
 EXPORT_SYMBOL_GPL(pci_epc_init_notify);
 
+/**
+ * pci_epc_bme_notify() - Notify the EPF device that the EPC device has received
+ *			  the BME event from the Root complex
+ * @epc: the EPC device that received the BME event
+ *
+ * Invoke to Notify the EPF device that the EPC device has received the Bus
+ * Master Enable (BME) event from the Root complex
+ */
+void pci_epc_bme_notify(struct pci_epc *epc)
+{
+	struct pci_epf *epf;
+
+	if (!epc || IS_ERR(epc))
+		return;
+
+	mutex_lock(&epc->list_lock);
+	list_for_each_entry(epf, &epc->pci_epf, list) {
+		mutex_lock(&epf->lock);
+		if (epf->event_ops && epf->event_ops->bme)
+			epf->event_ops->bme(epf);
+		mutex_unlock(&epf->lock);
+	}
+	mutex_unlock(&epc->list_lock);
+}
+EXPORT_SYMBOL_GPL(pci_epc_bme_notify);
+
 /**
  * pci_epc_destroy() - destroy the EPC device
  * @epc: the EPC device that has to be destroyed
diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h
index 63a6cc5e5282..5cb694031072 100644
--- a/include/linux/pci-epc.h
+++ b/include/linux/pci-epc.h
@@ -205,6 +205,7 @@ int pci_epc_add_epf(struct pci_epc *epc, struct pci_epf *epf,
 void pci_epc_linkup(struct pci_epc *epc);
 void pci_epc_linkdown(struct pci_epc *epc);
 void pci_epc_init_notify(struct pci_epc *epc);
+void pci_epc_bme_notify(struct pci_epc *epc);
 void pci_epc_remove_epf(struct pci_epc *epc, struct pci_epf *epf,
 			enum pci_epc_interface_type type);
 int pci_epc_write_header(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
diff --git a/include/linux/pci-epf.h b/include/linux/pci-epf.h
index f8e5a63d0c83..f34b3b32a0e7 100644
--- a/include/linux/pci-epf.h
+++ b/include/linux/pci-epf.h
@@ -72,11 +72,13 @@ struct pci_epf_ops {
  * @core_init: Callback for the EPC initialization complete event
  * @link_up: Callback for the EPC link up event
  * @link_down: Callback for the EPC link down event
+ * @bme: Callback for the EPC BME (Bus Master Enable) event
  */
 struct pci_epc_event_ops {
 	int (*core_init)(struct pci_epf *epf);
 	int (*link_up)(struct pci_epf *epf);
 	int (*link_down)(struct pci_epf *epf);
+	int (*bme)(struct pci_epf *epf);
 };
 
 /**
-- 
2.25.1

[PATCH v6 6/9] PCI: qcom-ep: Add support for Link down notification

[Manivannan Sadhasivam]

Add support to pass Link down notification to Endpoint function driver
so that the LINK_DOWN event can be processed by the function.

Reviewed-by: Kishon Vijay Abraham I <kishon@kernel.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/pci/controller/dwc/pcie-qcom-ep.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/pci/controller/dwc/pcie-qcom-ep.c b/drivers/pci/controller/dwc/pcie-qcom-ep.c
index 19b32839ea26..4ce01ff7527c 100644
--- a/drivers/pci/controller/dwc/pcie-qcom-ep.c
+++ b/drivers/pci/controller/dwc/pcie-qcom-ep.c
@@ -569,6 +569,7 @@ static irqreturn_t qcom_pcie_ep_global_irq_thread(int irq, void *data)
 	if (FIELD_GET(PARF_INT_ALL_LINK_DOWN, status)) {
 		dev_dbg(dev, "Received Linkdown event\n");
 		pcie_ep->link_status = QCOM_PCIE_EP_LINK_DOWN;
+		pci_epc_linkdown(pci->ep.epc);
 	} else if (FIELD_GET(PARF_INT_ALL_BME, status)) {
 		dev_dbg(dev, "Received BME event. Link is enabled!\n");
 		pcie_ep->link_status = QCOM_PCIE_EP_LINK_ENABLED;
-- 
2.25.1

[PATCH v6 7/9] PCI: qcom-ep: Add support for BME notification

[Manivannan Sadhasivam]

Add support to pass BME (Bus Master Enable) notification to Endpoint
function driver so that the BME event can be processed by the function.

Reviewed-by: Kishon Vijay Abraham I <kishon@kernel.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/pci/controller/dwc/pcie-qcom-ep.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/pci/controller/dwc/pcie-qcom-ep.c b/drivers/pci/controller/dwc/pcie-qcom-ep.c
index 4ce01ff7527c..1435f516d3f7 100644
--- a/drivers/pci/controller/dwc/pcie-qcom-ep.c
+++ b/drivers/pci/controller/dwc/pcie-qcom-ep.c
@@ -573,6 +573,7 @@ static irqreturn_t qcom_pcie_ep_global_irq_thread(int irq, void *data)
 	} else if (FIELD_GET(PARF_INT_ALL_BME, status)) {
 		dev_dbg(dev, "Received BME event. Link is enabled!\n");
 		pcie_ep->link_status = QCOM_PCIE_EP_LINK_ENABLED;
+		pci_epc_bme_notify(pci->ep.epc);
 	} else if (FIELD_GET(PARF_INT_ALL_PM_TURNOFF, status)) {
 		dev_dbg(dev, "Received PM Turn-off event! Entering L23\n");
 		val = readl_relaxed(pcie_ep->parf + PARF_PM_CTRL);
-- 
2.25.1

[PATCH v6 8/9] PCI: endpoint: Add PCI Endpoint function driver for MHI bus

[Manivannan Sadhasivam]

Add PCI Endpoint driver for the Qualcomm MHI (Modem Host Interface) bus.
The driver implements the MHI function over PCI in the endpoint device
such as SDX55 modem. The MHI endpoint function driver acts as a
controller driver for the MHI Endpoint stack and carries out all PCI
related activities like mapping the host memory using iATU, triggering
MSIs etc...

Reviewed-by: Kishon Vijay Abraham I <kishon@kernel.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/pci/endpoint/functions/Kconfig       |  10 +
 drivers/pci/endpoint/functions/Makefile      |   1 +
 drivers/pci/endpoint/functions/pci-epf-mhi.c | 465 +++++++++++++++++++
 3 files changed, 476 insertions(+)
 create mode 100644 drivers/pci/endpoint/functions/pci-epf-mhi.c

diff --git a/drivers/pci/endpoint/functions/Kconfig b/drivers/pci/endpoint/functions/Kconfig
index 9fd560886871..f5171b4fabbe 100644
--- a/drivers/pci/endpoint/functions/Kconfig
+++ b/drivers/pci/endpoint/functions/Kconfig
@@ -37,3 +37,13 @@ config PCI_EPF_VNTB
 	  between PCI Root Port and PCIe Endpoint.
 
 	  If in doubt, say "N" to disable Endpoint NTB driver.
+
+config PCI_EPF_MHI
+	tristate "PCI Endpoint driver for MHI bus"
+	depends on PCI_ENDPOINT && MHI_BUS_EP
+	help
+	   Enable this configuration option to enable the PCI Endpoint
+	   driver for Modem Host Interface (MHI) bus in Qualcomm Endpoint
+	   devices such as SDX55.
+
+	   If in doubt, say "N" to disable Endpoint driver for MHI bus.
diff --git a/drivers/pci/endpoint/functions/Makefile b/drivers/pci/endpoint/functions/Makefile
index 5c13001deaba..696473fce50e 100644
--- a/drivers/pci/endpoint/functions/Makefile
+++ b/drivers/pci/endpoint/functions/Makefile
@@ -6,3 +6,4 @@
 obj-$(CONFIG_PCI_EPF_TEST)		+= pci-epf-test.o
 obj-$(CONFIG_PCI_EPF_NTB)		+= pci-epf-ntb.o
 obj-$(CONFIG_PCI_EPF_VNTB) 		+= pci-epf-vntb.o
+obj-$(CONFIG_PCI_EPF_MHI)		+= pci-epf-mhi.o
diff --git a/drivers/pci/endpoint/functions/pci-epf-mhi.c b/drivers/pci/endpoint/functions/pci-epf-mhi.c
new file mode 100644
index 000000000000..0504ee13f692
--- /dev/null
+++ b/drivers/pci/endpoint/functions/pci-epf-mhi.c
@@ -0,0 +1,465 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PCI EPF driver for MHI Endpoint devices
+ *
+ * Copyright (C) 2023 Linaro Ltd.
+ * Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
+ */
+
+#include <linux/mhi_ep.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pci-epc.h>
+#include <linux/pci-epf.h>
+
+#define MHI_VERSION_1_0 0x01000000
+
+#define to_epf_mhi(cntrl) container_of(cntrl, struct pci_epf_mhi, cntrl)
+
+struct pci_epf_mhi_ep_info {
+	const struct mhi_ep_cntrl_config *config;
+	struct pci_epf_header *epf_header;
+	enum pci_barno bar_num;
+	u32 epf_flags;
+	u32 msi_count;
+	u32 mru;
+};
+
+#define MHI_EP_CHANNEL_CONFIG(ch_num, ch_name, direction)	\
+	{							\
+		.num = ch_num,					\
+		.name = ch_name,				\
+		.dir = direction,				\
+	}
+
+#define MHI_EP_CHANNEL_CONFIG_UL(ch_num, ch_name)		\
+	MHI_EP_CHANNEL_CONFIG(ch_num, ch_name, DMA_TO_DEVICE)
+
+#define MHI_EP_CHANNEL_CONFIG_DL(ch_num, ch_name)		\
+	MHI_EP_CHANNEL_CONFIG(ch_num, ch_name, DMA_FROM_DEVICE)
+
+static const struct mhi_ep_channel_config mhi_v1_channels[] = {
+	MHI_EP_CHANNEL_CONFIG_UL(0, "LOOPBACK"),
+	MHI_EP_CHANNEL_CONFIG_DL(1, "LOOPBACK"),
+	MHI_EP_CHANNEL_CONFIG_UL(2, "SAHARA"),
+	MHI_EP_CHANNEL_CONFIG_DL(3, "SAHARA"),
+	MHI_EP_CHANNEL_CONFIG_UL(4, "DIAG"),
+	MHI_EP_CHANNEL_CONFIG_DL(5, "DIAG"),
+	MHI_EP_CHANNEL_CONFIG_UL(6, "SSR"),
+	MHI_EP_CHANNEL_CONFIG_DL(7, "SSR"),
+	MHI_EP_CHANNEL_CONFIG_UL(8, "QDSS"),
+	MHI_EP_CHANNEL_CONFIG_DL(9, "QDSS"),
+	MHI_EP_CHANNEL_CONFIG_UL(10, "EFS"),
+	MHI_EP_CHANNEL_CONFIG_DL(11, "EFS"),
+	MHI_EP_CHANNEL_CONFIG_UL(12, "MBIM"),
+	MHI_EP_CHANNEL_CONFIG_DL(13, "MBIM"),
+	MHI_EP_CHANNEL_CONFIG_UL(14, "QMI"),
+	MHI_EP_CHANNEL_CONFIG_DL(15, "QMI"),
+	MHI_EP_CHANNEL_CONFIG_UL(16, "QMI"),
+	MHI_EP_CHANNEL_CONFIG_DL(17, "QMI"),
+	MHI_EP_CHANNEL_CONFIG_UL(18, "IP-CTRL-1"),
+	MHI_EP_CHANNEL_CONFIG_DL(19, "IP-CTRL-1"),
+	MHI_EP_CHANNEL_CONFIG_UL(20, "IPCR"),
+	MHI_EP_CHANNEL_CONFIG_DL(21, "IPCR"),
+	MHI_EP_CHANNEL_CONFIG_UL(32, "DUN"),
+	MHI_EP_CHANNEL_CONFIG_DL(33, "DUN"),
+	MHI_EP_CHANNEL_CONFIG_UL(46, "IP_SW0"),
+	MHI_EP_CHANNEL_CONFIG_DL(47, "IP_SW0"),
+};
+
+static const struct mhi_ep_cntrl_config mhi_v1_config = {
+	.max_channels = 128,
+	.num_channels = ARRAY_SIZE(mhi_v1_channels),
+	.ch_cfg = mhi_v1_channels,
+	.mhi_version = MHI_VERSION_1_0,
+};
+
+static struct pci_epf_header sdx55_header = {
+	.vendorid = PCI_VENDOR_ID_QCOM,
+	.deviceid = 0x0306,
+	.baseclass_code = PCI_BASE_CLASS_COMMUNICATION,
+	.subclass_code = PCI_CLASS_COMMUNICATION_MODEM & 0xff,
+	.interrupt_pin	= PCI_INTERRUPT_INTA,
+};
+
+static const struct pci_epf_mhi_ep_info sdx55_info = {
+	.config = &mhi_v1_config,
+	.epf_header = &sdx55_header,
+	.bar_num = BAR_0,
+	.epf_flags = PCI_BASE_ADDRESS_MEM_TYPE_32,
+	.msi_count = 32,
+	.mru = 0x8000,
+};
+
+struct pci_epf_mhi {
+	const struct pci_epf_mhi_ep_info *info;
+	struct mhi_ep_cntrl mhi_cntrl;
+	struct pci_epf *epf;
+	struct mutex lock;
+	void __iomem *mmio;
+	resource_size_t mmio_phys;
+	u32 mmio_size;
+	int irq;
+};
+
+static int __pci_epf_mhi_alloc_map(struct mhi_ep_cntrl *mhi_cntrl, u64 pci_addr,
+				 phys_addr_t *paddr, void __iomem **vaddr,
+				 size_t offset, size_t size)
+{
+	struct pci_epf_mhi *epf_mhi = to_epf_mhi(mhi_cntrl);
+	struct pci_epf *epf = epf_mhi->epf;
+	struct pci_epc *epc = epf->epc;
+	int ret;
+
+	*vaddr = pci_epc_mem_alloc_addr(epc, paddr, size + offset);
+	if (!vaddr)
+		return -ENOMEM;
+
+	ret = pci_epc_map_addr(epc, epf->func_no, epf->vfunc_no, *paddr,
+			       pci_addr - offset, size + offset);
+	if (ret) {
+		pci_epc_mem_free_addr(epc, *paddr, *vaddr, size + offset);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int pci_epf_mhi_alloc_map(struct mhi_ep_cntrl *mhi_cntrl, u64 pci_addr,
+				 phys_addr_t *paddr, void __iomem **vaddr,
+				 size_t size)
+{
+	struct pci_epf_mhi *epf_mhi = to_epf_mhi(mhi_cntrl);
+	struct pci_epc *epc = epf_mhi->epf->epc;
+	size_t offset = pci_addr & (epc->mem->window.page_size - 1);
+	int ret;
+
+	ret = __pci_epf_mhi_alloc_map(mhi_cntrl, pci_addr, paddr, vaddr,
+				      offset, size);
+	if (ret)
+		return ret;
+
+	*paddr = *paddr + offset;
+	*vaddr = *vaddr + offset;
+
+	return 0;
+}
+
+static void __pci_epf_mhi_unmap_free(struct mhi_ep_cntrl *mhi_cntrl,
+				     u64 pci_addr, phys_addr_t paddr,
+				     void __iomem *vaddr, size_t offset,
+				     size_t size)
+{
+	struct pci_epf_mhi *epf_mhi = to_epf_mhi(mhi_cntrl);
+	struct pci_epf *epf = epf_mhi->epf;
+	struct pci_epc *epc = epf->epc;
+
+	pci_epc_unmap_addr(epc, epf->func_no, epf->vfunc_no, paddr - offset);
+	pci_epc_mem_free_addr(epc, paddr - offset, vaddr - offset,
+			      size + offset);
+}
+
+static void pci_epf_mhi_unmap_free(struct mhi_ep_cntrl *mhi_cntrl, u64 pci_addr,
+				   phys_addr_t paddr, void __iomem *vaddr,
+				   size_t size)
+{
+	struct pci_epf_mhi *epf_mhi = to_epf_mhi(mhi_cntrl);
+	struct pci_epf *epf = epf_mhi->epf;
+	struct pci_epc *epc = epf->epc;
+	size_t offset = pci_addr & (epc->mem->window.page_size - 1);
+
+	__pci_epf_mhi_unmap_free(mhi_cntrl, pci_addr, paddr, vaddr, offset,
+				 size);
+}
+
+static void pci_epf_mhi_raise_irq(struct mhi_ep_cntrl *mhi_cntrl, u32 vector)
+{
+	struct pci_epf_mhi *epf_mhi = to_epf_mhi(mhi_cntrl);
+	struct pci_epf *epf = epf_mhi->epf;
+	struct pci_epc *epc = epf->epc;
+
+	/*
+	 * MHI supplies 0 based MSI vector but the API expects the vector to be
+	 * 1 based, so we need to increment the vector by 1.
+	 */
+	pci_epc_raise_irq(epc, epf->func_no, epf->vfunc_no, PCI_EPC_IRQ_MSI,
+			  vector + 1);
+}
+
+static int pci_epf_mhi_read_from_host(struct mhi_ep_cntrl *mhi_cntrl, u64 from,
+				      void *to, size_t size)
+{
+	struct pci_epf_mhi *epf_mhi = to_epf_mhi(mhi_cntrl);
+	size_t offset = from % SZ_4K;
+	void __iomem *tre_buf;
+	phys_addr_t tre_phys;
+	int ret;
+
+	mutex_lock(&epf_mhi->lock);
+
+	ret = __pci_epf_mhi_alloc_map(mhi_cntrl, from, &tre_phys, &tre_buf,
+				      offset, size);
+	if (ret) {
+		mutex_unlock(&epf_mhi->lock);
+		return ret;
+	}
+
+	memcpy_fromio(to, tre_buf + offset, size);
+
+	__pci_epf_mhi_unmap_free(mhi_cntrl, from, tre_phys, tre_buf, offset,
+				 size);
+
+	mutex_unlock(&epf_mhi->lock);
+
+	return 0;
+}
+
+static int pci_epf_mhi_write_to_host(struct mhi_ep_cntrl *mhi_cntrl,
+				     void *from, u64 to, size_t size)
+{
+	struct pci_epf_mhi *epf_mhi = to_epf_mhi(mhi_cntrl);
+	size_t offset = to % SZ_4K;
+	void __iomem *tre_buf;
+	phys_addr_t tre_phys;
+	int ret;
+
+	mutex_lock(&epf_mhi->lock);
+
+	ret = __pci_epf_mhi_alloc_map(mhi_cntrl, to, &tre_phys, &tre_buf,
+				      offset, size);
+	if (ret) {
+		mutex_unlock(&epf_mhi->lock);
+		return ret;
+	}
+
+	memcpy_toio(tre_buf + offset, from, size);
+
+	__pci_epf_mhi_unmap_free(mhi_cntrl, to, tre_phys, tre_buf, offset,
+				 size);
+
+	mutex_unlock(&epf_mhi->lock);
+
+	return 0;
+}
+
+static int pci_epf_mhi_core_init(struct pci_epf *epf)
+{
+	struct pci_epf_mhi *epf_mhi = epf_get_drvdata(epf);
+	const struct pci_epf_mhi_ep_info *info = epf_mhi->info;
+	struct pci_epf_bar *epf_bar = &epf->bar[info->bar_num];
+	struct pci_epc *epc = epf->epc;
+	struct device *dev = &epf->dev;
+	int ret;
+
+	epf_bar->phys_addr = epf_mhi->mmio_phys;
+	epf_bar->size = epf_mhi->mmio_size;
+	epf_bar->barno = info->bar_num;
+	epf_bar->flags = info->epf_flags;
+	ret = pci_epc_set_bar(epc, epf->func_no, epf->vfunc_no, epf_bar);
+	if (ret) {
+		dev_err(dev, "Failed to set BAR: %d\n", ret);
+		return ret;
+	}
+
+	ret = pci_epc_set_msi(epc, epf->func_no, epf->vfunc_no,
+			      order_base_2(info->msi_count));
+	if (ret) {
+		dev_err(dev, "Failed to set MSI configuration: %d\n", ret);
+		return ret;
+	}
+
+	ret = pci_epc_write_header(epc, epf->func_no, epf->vfunc_no,
+				   epf->header);
+	if (ret) {
+		dev_err(dev, "Failed to set Configuration header: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int pci_epf_mhi_link_up(struct pci_epf *epf)
+{
+	struct pci_epf_mhi *epf_mhi = epf_get_drvdata(epf);
+	const struct pci_epf_mhi_ep_info *info = epf_mhi->info;
+	struct mhi_ep_cntrl *mhi_cntrl = &epf_mhi->mhi_cntrl;
+	struct pci_epc *epc = epf->epc;
+	struct device *dev = &epf->dev;
+	int ret;
+
+	mhi_cntrl->mmio = epf_mhi->mmio;
+	mhi_cntrl->irq = epf_mhi->irq;
+	mhi_cntrl->mru = info->mru;
+
+	/* Assign the struct dev of PCI EP as MHI controller device */
+	mhi_cntrl->cntrl_dev = epc->dev.parent;
+	mhi_cntrl->raise_irq = pci_epf_mhi_raise_irq;
+	mhi_cntrl->alloc_map = pci_epf_mhi_alloc_map;
+	mhi_cntrl->unmap_free = pci_epf_mhi_unmap_free;
+	mhi_cntrl->read_from_host = pci_epf_mhi_read_from_host;
+	mhi_cntrl->write_to_host = pci_epf_mhi_write_to_host;
+
+	/* Register the MHI EP controller */
+	ret = mhi_ep_register_controller(mhi_cntrl, info->config);
+	if (ret) {
+		dev_err(dev, "Failed to register MHI EP controller: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int pci_epf_mhi_link_down(struct pci_epf *epf)
+{
+	struct pci_epf_mhi *epf_mhi = epf_get_drvdata(epf);
+	struct mhi_ep_cntrl *mhi_cntrl = &epf_mhi->mhi_cntrl;
+
+	if (mhi_cntrl->mhi_dev) {
+		mhi_ep_power_down(mhi_cntrl);
+		mhi_ep_unregister_controller(mhi_cntrl);
+	}
+
+	return 0;
+}
+
+static int pci_epf_mhi_bme(struct pci_epf *epf)
+{
+	struct pci_epf_mhi *epf_mhi = epf_get_drvdata(epf);
+	struct mhi_ep_cntrl *mhi_cntrl = &epf_mhi->mhi_cntrl;
+	struct device *dev = &epf->dev;
+	int ret;
+
+	/*
+	 * Power up the MHI EP stack if link is up and stack is in power down
+	 * state.
+	 */
+	if (!mhi_cntrl->enabled && mhi_cntrl->mhi_dev) {
+		ret = mhi_ep_power_up(mhi_cntrl);
+		if (ret) {
+			dev_err(dev, "Failed to power up MHI EP: %d\n", ret);
+			mhi_ep_unregister_controller(mhi_cntrl);
+		}
+	}
+
+	return 0;
+}
+
+static int pci_epf_mhi_bind(struct pci_epf *epf)
+{
+	struct pci_epf_mhi *epf_mhi = epf_get_drvdata(epf);
+	struct pci_epc *epc = epf->epc;
+	struct platform_device *pdev = to_platform_device(epc->dev.parent);
+	struct device *dev = &epf->dev;
+	struct resource *res;
+	int ret;
+
+	/* Get MMIO base address from Endpoint controller */
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mmio");
+	epf_mhi->mmio_phys = res->start;
+	epf_mhi->mmio_size = resource_size(res);
+
+	epf_mhi->mmio = ioremap(epf_mhi->mmio_phys, epf_mhi->mmio_size);
+	if (IS_ERR(epf_mhi->mmio))
+		return PTR_ERR(epf_mhi->mmio);
+
+	ret = platform_get_irq_byname(pdev, "doorbell");
+	if (ret < 0) {
+		dev_err(dev, "Failed to get Doorbell IRQ\n");
+		iounmap(epf_mhi->mmio);
+		return ret;
+	}
+
+	epf_mhi->irq = ret;
+
+	return 0;
+}
+
+static void pci_epf_mhi_unbind(struct pci_epf *epf)
+{
+	struct pci_epf_mhi *epf_mhi = epf_get_drvdata(epf);
+	const struct pci_epf_mhi_ep_info *info = epf_mhi->info;
+	struct pci_epf_bar *epf_bar = &epf->bar[info->bar_num];
+	struct mhi_ep_cntrl *mhi_cntrl = &epf_mhi->mhi_cntrl;
+	struct pci_epc *epc = epf->epc;
+
+	/*
+	 * Forcefully power down the MHI EP stack. Only way to bring the MHI EP
+	 * stack back to working state after successive bind is by getting BME
+	 * from host.
+	 */
+	if (mhi_cntrl->mhi_dev) {
+		mhi_ep_power_down(mhi_cntrl);
+		mhi_ep_unregister_controller(mhi_cntrl);
+	}
+
+	iounmap(epf_mhi->mmio);
+	pci_epc_clear_bar(epc, epf->func_no, epf->vfunc_no, epf_bar);
+}
+
+static struct pci_epc_event_ops pci_epf_mhi_event_ops = {
+	.core_init = pci_epf_mhi_core_init,
+	.link_up = pci_epf_mhi_link_up,
+	.link_down = pci_epf_mhi_link_down,
+	.bme = pci_epf_mhi_bme,
+};
+
+static int pci_epf_mhi_probe(struct pci_epf *epf,
+			     const struct pci_epf_device_id *id)
+{
+	struct pci_epf_mhi_ep_info *info =
+			(struct pci_epf_mhi_ep_info *)id->driver_data;
+	struct pci_epf_mhi *epf_mhi;
+	struct device *dev = &epf->dev;
+
+	epf_mhi = devm_kzalloc(dev, sizeof(*epf_mhi), GFP_KERNEL);
+	if (!epf_mhi)
+		return -ENOMEM;
+
+	epf->header = info->epf_header;
+	epf_mhi->info = info;
+	epf_mhi->epf = epf;
+
+	epf->event_ops = &pci_epf_mhi_event_ops;
+
+	mutex_init(&epf_mhi->lock);
+
+	epf_set_drvdata(epf, epf_mhi);
+
+	return 0;
+}
+
+static const struct pci_epf_device_id pci_epf_mhi_ids[] = {
+	{
+		.name = "sdx55", .driver_data = (kernel_ulong_t)&sdx55_info,
+	},
+	{},
+};
+
+static struct pci_epf_ops pci_epf_mhi_ops = {
+	.unbind	= pci_epf_mhi_unbind,
+	.bind	= pci_epf_mhi_bind,
+};
+
+static struct pci_epf_driver pci_epf_mhi_driver = {
+	.driver.name	= "pci_epf_mhi",
+	.probe		= pci_epf_mhi_probe,
+	.id_table	= pci_epf_mhi_ids,
+	.ops		= &pci_epf_mhi_ops,
+	.owner		= THIS_MODULE,
+};
+
+static int __init pci_epf_mhi_init(void)
+{
+	return pci_epf_register_driver(&pci_epf_mhi_driver);
+}
+module_init(pci_epf_mhi_init);
+
+static void __exit pci_epf_mhi_exit(void)
+{
+	pci_epf_unregister_driver(&pci_epf_mhi_driver);
+}
+module_exit(pci_epf_mhi_exit);
+
+MODULE_DESCRIPTION("PCI EPF driver for MHI Endpoint devices");
+MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>");
+MODULE_LICENSE("GPL");
-- 
2.25.1

Re: [PATCH v6 8/9] PCI: endpoint: Add PCI Endpoint function driver for MHI bus

[Bjorn Helgaas]

On Fri, Jun 02, 2023 at 05:17:55PM +0530, Manivannan Sadhasivam wrote:
> Add PCI Endpoint driver for the Qualcomm MHI (Modem Host Interface) bus.
> The driver implements the MHI function over PCI in the endpoint device
> such as SDX55 modem. The MHI endpoint function driver acts as a
> controller driver for the MHI Endpoint stack and carries out all PCI
> related activities like mapping the host memory using iATU, triggering
> MSIs etc...
> ...

> +static int pci_epf_mhi_bind(struct pci_epf *epf)
> +{
> ...

> +	ret = platform_get_irq_byname(pdev, "doorbell");
> +	if (ret < 0) {
> +		dev_err(dev, "Failed to get Doorbell IRQ\n");

This dev_err() causes this new warning from the 0-day robot [1]:

  drivers/pci/endpoint/functions/pci-epf-mhi.c:362:2-9: line 362 is redundant because platform_get_irq() already prints an error

Maybe we could drop it?

Bjorn

[1] https://lore.kernel.org/all/20230607163937.ZTc-D%25lkp@intel.com/

Re: [PATCH v6 8/9] PCI: endpoint: Add PCI Endpoint function driver for MHI bus

[Bjorn Helgaas]

[+cc Yang Li, sorry I didn't notice your patch earlier:
https://lore.kernel.org/r/20230607093514.104012-1-yang.lee@linux.alibaba.com]

I think we can squash this into the original commit since it hasn't
gone upstream yet.  Also note that removing the dev_err() apparently
makes "dev" unused, so we'd have to remove that as well, based on this
report [2].

[2] https://lore.kernel.org/r/202306080418.i64hTj5T-lkp@intel.com

On Wed, Jun 07, 2023 at 03:49:25PM -0500, Bjorn Helgaas wrote:
> On Fri, Jun 02, 2023 at 05:17:55PM +0530, Manivannan Sadhasivam wrote:
> > Add PCI Endpoint driver for the Qualcomm MHI (Modem Host Interface) bus.
> > The driver implements the MHI function over PCI in the endpoint device
> > such as SDX55 modem. The MHI endpoint function driver acts as a
> > controller driver for the MHI Endpoint stack and carries out all PCI
> > related activities like mapping the host memory using iATU, triggering
> > MSIs etc...
> > ...
> 
> > +static int pci_epf_mhi_bind(struct pci_epf *epf)
> > +{
> > ...
> 
> > +	ret = platform_get_irq_byname(pdev, "doorbell");
> > +	if (ret < 0) {
> > +		dev_err(dev, "Failed to get Doorbell IRQ\n");
> 
> This dev_err() causes this new warning from the 0-day robot [1]:
> 
>   drivers/pci/endpoint/functions/pci-epf-mhi.c:362:2-9: line 362 is redundant because platform_get_irq() already prints an error
> 
> Maybe we could drop it?
> 
> Bjorn
> 
> [1] https://lore.kernel.org/all/20230607163937.ZTc-D%25lkp@intel.com/

Re: [PATCH v6 8/9] PCI: endpoint: Add PCI Endpoint function driver for MHI bus

[Manivannan Sadhasivam]

On Wed, Jun 07, 2023 at 04:19:41PM -0500, Bjorn Helgaas wrote:
> [+cc Yang Li, sorry I didn't notice your patch earlier:
> https://lore.kernel.org/r/20230607093514.104012-1-yang.lee@linux.alibaba.com]
> 
> I think we can squash this into the original commit since it hasn't
> gone upstream yet.  Also note that removing the dev_err() apparently
> makes "dev" unused, so we'd have to remove that as well, based on this
> report [2].
> 
> [2] https://lore.kernel.org/r/202306080418.i64hTj5T-lkp@intel.com
> 
> On Wed, Jun 07, 2023 at 03:49:25PM -0500, Bjorn Helgaas wrote:
> > On Fri, Jun 02, 2023 at 05:17:55PM +0530, Manivannan Sadhasivam wrote:
> > > Add PCI Endpoint driver for the Qualcomm MHI (Modem Host Interface) bus.
> > > The driver implements the MHI function over PCI in the endpoint device
> > > such as SDX55 modem. The MHI endpoint function driver acts as a
> > > controller driver for the MHI Endpoint stack and carries out all PCI
> > > related activities like mapping the host memory using iATU, triggering
> > > MSIs etc...
> > > ...
> > 
> > > +static int pci_epf_mhi_bind(struct pci_epf *epf)
> > > +{
> > > ...
> > 
> > > +	ret = platform_get_irq_byname(pdev, "doorbell");
> > > +	if (ret < 0) {
> > > +		dev_err(dev, "Failed to get Doorbell IRQ\n");
> > 
> > This dev_err() causes this new warning from the 0-day robot [1]:
> > 
> >   drivers/pci/endpoint/functions/pci-epf-mhi.c:362:2-9: line 362 is redundant because platform_get_irq() already prints an error
> > 
> > Maybe we could drop it?
> > 

Right. I think Lorenzo can handle both while squashing.

- Mani

> > Bjorn
> > 
> > [1] https://lore.kernel.org/all/20230607163937.ZTc-D%25lkp@intel.com/

-- 
மணிவண்ணன் சதாசிவம்

Re: [PATCH v6 8/9] PCI: endpoint: Add PCI Endpoint function driver for MHI bus

[Lorenzo Pieralisi]

On Wed, Jun 07, 2023 at 04:19:41PM -0500, Bjorn Helgaas wrote:
> [+cc Yang Li, sorry I didn't notice your patch earlier:
> https://lore.kernel.org/r/20230607093514.104012-1-yang.lee@linux.alibaba.com]
> 
> I think we can squash this into the original commit since it hasn't
> gone upstream yet.  Also note that removing the dev_err() apparently
> makes "dev" unused, so we'd have to remove that as well, based on this
> report [2].
> 
> [2] https://lore.kernel.org/r/202306080418.i64hTj5T-lkp@intel.com

Done.

Thanks,
Lorenzo

> On Wed, Jun 07, 2023 at 03:49:25PM -0500, Bjorn Helgaas wrote:
> > On Fri, Jun 02, 2023 at 05:17:55PM +0530, Manivannan Sadhasivam wrote:
> > > Add PCI Endpoint driver for the Qualcomm MHI (Modem Host Interface) bus.
> > > The driver implements the MHI function over PCI in the endpoint device
> > > such as SDX55 modem. The MHI endpoint function driver acts as a
> > > controller driver for the MHI Endpoint stack and carries out all PCI
> > > related activities like mapping the host memory using iATU, triggering
> > > MSIs etc...
> > > ...
> > 
> > > +static int pci_epf_mhi_bind(struct pci_epf *epf)
> > > +{
> > > ...
> > 
> > > +	ret = platform_get_irq_byname(pdev, "doorbell");
> > > +	if (ret < 0) {
> > > +		dev_err(dev, "Failed to get Doorbell IRQ\n");
> > 
> > This dev_err() causes this new warning from the 0-day robot [1]:
> > 
> >   drivers/pci/endpoint/functions/pci-epf-mhi.c:362:2-9: line 362 is redundant because platform_get_irq() already prints an error
> > 
> > Maybe we could drop it?
> > 
> > Bjorn
> > 
> > [1] https://lore.kernel.org/all/20230607163937.ZTc-D%25lkp@intel.com/

[PATCH v6 9/9] MAINTAINERS: Add PCI MHI endpoint function driver under MHI bus

[Manivannan Sadhasivam]

Add PCI endpoint driver for MHI bus under the MHI bus entry in MAINTAINERS
file.

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 MAINTAINERS | 1 +
 1 file changed, 1 insertion(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 07625a47cf08..a4ac2d567334 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -13630,6 +13630,7 @@ F:	Documentation/ABI/stable/sysfs-bus-mhi
 F:	Documentation/mhi/
 F:	drivers/bus/mhi/
 F:	drivers/net/mhi_*
+F:	drivers/pci/endpoint/functions/pci-epf-mhi.c
 F:	include/linux/mhi.h
 
 MICROBLAZE ARCHITECTURE
-- 
2.25.1

Re: [PATCH v6 9/9] MAINTAINERS: Add PCI MHI endpoint function driver under MHI bus

[Damien Le Moal]

On 6/2/23 20:47, Manivannan Sadhasivam wrote:
> Add PCI endpoint driver for MHI bus under the MHI bus entry in MAINTAINERS
> file.
> 
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

Reviewed-by: Damien Le Moal <dlemoal@kernel.org>

-- 
Damien Le Moal
Western Digital Research

Re: [PATCH v6 0/9] Add support for MHI Endpoint function driver

[Lorenzo Pieralisi]

On Fri, 02 Jun 2023 17:17:47 +0530, Manivannan Sadhasivam wrote:
> This series adds support for Modem Host Interface (MHI) Endpoint function
> driver and few updates to the PCI endpoint core.
> 
> MHI
> ===
> 
> MHI is the communication protocol used by the host machines to control and
> communicate with the Qualcomm modems/WLAN devices over any high speed physical
> bus like PCIe. In Linux kernel, MHI is modeled as a bus driver [1] and there
> are two instances of MHI used in a typical setup.
> 
> [...]

Applied [with few changes, please check] to controller/endpoint, thanks!

[1/9] PCI: endpoint: Add missing documentation about the MSI/MSI-X range
      https://git.kernel.org/pci/pci/c/4753e6a0fe22
[2/9] PCI: endpoint: Pass EPF device ID to the probe function
      https://git.kernel.org/pci/pci/c/765b0e80681a
[3/9] PCI: endpoint: Return error if EPC is started/stopped multiple times
      https://git.kernel.org/pci/pci/c/0ff3de7a6c87
[4/9] PCI: endpoint: Add linkdown notifier support
      https://git.kernel.org/pci/pci/c/755cb1cc2615
[5/9] PCI: endpoint: Add BME notifier support
      https://git.kernel.org/pci/pci/c/a2bd0e62f6fd
[6/9] PCI: qcom-ep: Add support for Link down notification
      https://git.kernel.org/pci/pci/c/c53dc1547231
[7/9] PCI: qcom-ep: Add support for BME notification
      https://git.kernel.org/pci/pci/c/258dfe82065c
[8/9] PCI: endpoint: Add PCI Endpoint function driver for MHI bus
      https://git.kernel.org/pci/pci/c/fd0fda1ef61a
[9/9] MAINTAINERS: Add PCI MHI endpoint function driver under MHI bus
      https://git.kernel.org/pci/pci/c/71f1861bb90d

Thanks,
Lorenzo