Commit 2cf1e703 authored by Ioana Ciornei's avatar Ioana Ciornei Committed by Greg Kroah-Hartman
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bus: fsl-mc: add fsl-mc userspace support 



Adding userspace support for the MC (Management Complex) means exporting
an ioctl capable device file representing the root resource container.

This new functionality in the fsl-mc bus driver intends to provide
userspace applications an interface to interact with the MC firmware.

Commands that are composed in userspace are sent to the MC firmware
through the FSL_MC_SEND_MC_COMMAND ioctl.  By default the implicit MC
I/O portal is used for this operation, but if the implicit one is busy,
a dynamic portal is allocated and then freed upon execution.

The command received through the ioctl interface is checked against a
known whitelist of accepted MC commands. Commands that attempt a change
in hardware configuration will need CAP_NET_ADMIN, while commands used
in debugging do not need it.

Acked-by: default avatarLaurentiu Tudor <laurentiu.tudor@nxp.com>
Signed-off-by: default avatarIoana Ciornei <ioana.ciornei@nxp.com>
Link: https://lore.kernel.org/r/20210114170752.2927915-4-ciorneiioana@gmail.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 46707989

Documentation/userspace-api/ioctl/ioctl-number.rst

+1 −0
Original line number Diff line number Diff line
@@ -180,6 +180,7 @@ Code Seq# Include File Comments 
'R'   00-1F  linux/random.h                                          conflict!

'R'   01     linux/rfkill.h                                          conflict!

'R'   C0-DF  net/bluetooth/rfcomm.h

'R'   E0     uapi/linux/fsl_mc.h

'S'   all    linux/cdrom.h                                           conflict!

'S'   80-81  scsi/scsi_ioctl.h                                       conflict!

'S'   82-FF  scsi/scsi.h                                             conflict!

drivers/bus/fsl-mc/Kconfig

+7 −0
Original line number Diff line number Diff line
@@ -14,3 +14,10 @@ config FSL_MC_BUS 
	  architecture.  The fsl-mc bus driver handles discovery of

	  DPAA2 objects (which are represented as Linux devices) and

	  binding objects to drivers.



config FSL_MC_UAPI_SUPPORT

	bool "Management Complex (MC) userspace support"

	depends on FSL_MC_BUS

	help

	  Provides userspace support for interrogating, creating, destroying or

	  configuring DPAA2 objects exported by the Management Complex.

drivers/bus/fsl-mc/Makefile

+3 −0
Original line number Diff line number Diff line
@@ -16,3 +16,6 @@ mc-bus-driver-objs := fsl-mc-bus.o \ 
		      fsl-mc-allocator.o \

		      fsl-mc-msi.o \

		      dpmcp.o



# MC userspace support

obj-$(CONFIG_FSL_MC_UAPI_SUPPORT) += fsl-mc-uapi.o

drivers/bus/fsl-mc/dprc-driver.c

+12 −0
Original line number Diff line number Diff line
@@ -603,6 +603,7 @@ int dprc_setup(struct fsl_mc_device *mc_dev) 
	struct irq_domain *mc_msi_domain;

	bool mc_io_created = false;

	bool msi_domain_set = false;

	bool uapi_created = false;

	u16 major_ver, minor_ver;

	size_t region_size;

	int error;
@@ -635,6 +636,11 @@ int dprc_setup(struct fsl_mc_device *mc_dev) 
			return error;



		mc_io_created = true;

	} else {

		error = fsl_mc_uapi_create_device_file(mc_bus);

		if (error < 0)

			return -EPROBE_DEFER;

		uapi_created = true;

	}



	mc_msi_domain = fsl_mc_find_msi_domain(&mc_dev->dev);
@@ -692,6 +698,9 @@ int dprc_setup(struct fsl_mc_device *mc_dev) 
		mc_dev->mc_io = NULL;

	}



	if (uapi_created)

		fsl_mc_uapi_remove_device_file(mc_bus);



	return error;

}

EXPORT_SYMBOL_GPL(dprc_setup);
@@ -763,6 +772,7 @@ static void dprc_teardown_irq(struct fsl_mc_device *mc_dev) 


int dprc_cleanup(struct fsl_mc_device *mc_dev)

{

	struct fsl_mc_bus *mc_bus = to_fsl_mc_bus(mc_dev);

	int error;



	/* this function should be called only for DPRCs, it
@@ -793,6 +803,8 @@ int dprc_cleanup(struct fsl_mc_device *mc_dev) 
	if (!fsl_mc_is_root_dprc(&mc_dev->dev)) {

		fsl_destroy_mc_io(mc_dev->mc_io);

		mc_dev->mc_io = NULL;

	} else {

		fsl_mc_uapi_remove_device_file(mc_bus);

	}



	return 0;

drivers/bus/fsl-mc/fsl-mc-private.h

+39 −0
Original line number Diff line number Diff line
@@ -10,6 +10,8 @@ 


#include <linux/fsl/mc.h>

#include <linux/mutex.h>

#include <linux/ioctl.h>

#include <linux/miscdevice.h>



/*

 * Data Path Management Complex (DPMNG) General API
@@ -542,6 +544,22 @@ struct fsl_mc_resource_pool { 
	struct fsl_mc_bus *mc_bus;

};



/**

 * struct fsl_mc_uapi - information associated with a device file

 * @misc: struct miscdevice linked to the root dprc

 * @device: newly created device in /dev

 * @mutex: mutex lock to serialize the open/release operations

 * @local_instance_in_use: local MC I/O instance in use or not

 * @static_mc_io: pointer to the static MC I/O object

 */

struct fsl_mc_uapi {

	struct miscdevice misc;

	struct device *device;

	struct mutex mutex; /* serialize open/release operations */

	u32 local_instance_in_use;

	struct fsl_mc_io *static_mc_io;

};



/**

 * struct fsl_mc_bus - logical bus that corresponds to a physical DPRC

 * @mc_dev: fsl-mc device for the bus device itself.
@@ -551,6 +569,7 @@ struct fsl_mc_resource_pool { 
 * @irq_resources: Pointer to array of IRQ objects for the IRQ pool

 * @scan_mutex: Serializes bus scanning

 * @dprc_attr: DPRC attributes

 * @uapi_misc: struct that abstracts the interaction with userspace

 */

struct fsl_mc_bus {

	struct fsl_mc_device mc_dev;
@@ -558,6 +577,7 @@ struct fsl_mc_bus { 
	struct fsl_mc_device_irq *irq_resources;

	struct mutex scan_mutex;    /* serializes bus scanning */

	struct dprc_attributes dprc_attr;

	struct fsl_mc_uapi uapi_misc;

};



#define to_fsl_mc_bus(_mc_dev) \
@@ -614,4 +634,23 @@ struct fsl_mc_device *fsl_mc_device_lookup(struct fsl_mc_obj_desc *obj_desc, 


u16 mc_cmd_hdr_read_cmdid(struct fsl_mc_command *cmd);



#ifdef CONFIG_FSL_MC_UAPI_SUPPORT



int fsl_mc_uapi_create_device_file(struct fsl_mc_bus *mc_bus);



void fsl_mc_uapi_remove_device_file(struct fsl_mc_bus *mc_bus);



#else



static inline int fsl_mc_uapi_create_device_file(struct fsl_mc_bus *mc_bus)

{

	return 0;

}



static inline void fsl_mc_uapi_remove_device_file(struct fsl_mc_bus *mc_bus)

{

}



#endif



#endif /* _FSL_MC_PRIVATE_H_ */