diff mbox series

[v4,4/7] firmware: arm_ffa: Add initial Arm FFA driver support

Message ID 20210212154614.38604-5-sudeep.holla@arm.com
State Superseded
Headers show
Series firmware: Add initial support for Arm FF-A | expand

Commit Message

Sudeep Holla Feb. 12, 2021, 3:46 p.m. UTC
This just add a basic driver that sets up the transport(e.g. SMCCC),
checks the FFA version implemented, get the partition ID for self and
sets up the Tx/Rx buffers for communication.

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

---
 drivers/firmware/arm_ffa/Makefile |   3 +-
 drivers/firmware/arm_ffa/bus.c    |  14 +-
 drivers/firmware/arm_ffa/common.h |  26 +++
 drivers/firmware/arm_ffa/driver.c | 297 ++++++++++++++++++++++++++++++
 4 files changed, 329 insertions(+), 11 deletions(-)
 create mode 100644 drivers/firmware/arm_ffa/common.h
 create mode 100644 drivers/firmware/arm_ffa/driver.c

-- 
2.25.1

Comments

Jens Wiklander March 19, 2021, 7:25 a.m. UTC | #1
On Fri, Feb 12, 2021 at 03:46:11PM +0000, Sudeep Holla wrote:
> This just add a basic driver that sets up the transport(e.g. SMCCC),

> checks the FFA version implemented, get the partition ID for self and

> sets up the Tx/Rx buffers for communication.

> 

> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

> ---

>  drivers/firmware/arm_ffa/Makefile |   3 +-

>  drivers/firmware/arm_ffa/bus.c    |  14 +-

>  drivers/firmware/arm_ffa/common.h |  26 +++

>  drivers/firmware/arm_ffa/driver.c | 297 ++++++++++++++++++++++++++++++

>  4 files changed, 329 insertions(+), 11 deletions(-)

>  create mode 100644 drivers/firmware/arm_ffa/common.h

>  create mode 100644 drivers/firmware/arm_ffa/driver.c

> 

> diff --git a/drivers/firmware/arm_ffa/Makefile b/drivers/firmware/arm_ffa/Makefile

> index bfe4323a8784..82d0d35c5324 100644

> --- a/drivers/firmware/arm_ffa/Makefile

> +++ b/drivers/firmware/arm_ffa/Makefile

> @@ -1,4 +1,5 @@

>  # SPDX-License-Identifier: GPL-2.0-only

>  ffa-bus-y = bus.o

> -ffa-module-objs := $(ffa-bus-y)

> +ffa-driver-y = driver.o

> +ffa-module-objs := $(ffa-bus-y) $(ffa-driver-y)

>  obj-$(CONFIG_ARM_FFA_TRANSPORT) = ffa-module.o

> diff --git a/drivers/firmware/arm_ffa/bus.c b/drivers/firmware/arm_ffa/bus.c

> index 3b01a3586f7b..9debdc87111c 100644

> --- a/drivers/firmware/arm_ffa/bus.c

> +++ b/drivers/firmware/arm_ffa/bus.c

> @@ -13,6 +13,8 @@

>  #include <linux/slab.h>

>  #include <linux/types.h>

>  

> +#include "common.h"

> +

>  static int ffa_device_match(struct device *dev, struct device_driver *drv)

>  {

>  	const struct ffa_device_id *id_table;

> @@ -167,21 +169,13 @@ void ffa_device_unregister(struct ffa_device *ffa_dev)

>  }

>  EXPORT_SYMBOL_GPL(ffa_device_unregister);

>  

> -static int __init arm_ffa_bus_init(void)

> +int __init arm_ffa_bus_init(void)

>  {

>  	return bus_register(&ffa_bus_type);

>  }

> -module_init(arm_ffa_bus_init);

>  

> -static void __exit arm_ffa_bus_exit(void)

> +void __exit arm_ffa_bus_exit(void)

>  {

>  	ffa_devices_unregister();

>  	bus_unregister(&ffa_bus_type);

>  }

> -

> -module_exit(arm_ffa_bus_exit);

> -

> -MODULE_ALIAS("arm-ffa-bus");

> -MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");

> -MODULE_DESCRIPTION("Arm FF-A bus driver");

> -MODULE_LICENSE("GPL v2");

> diff --git a/drivers/firmware/arm_ffa/common.h b/drivers/firmware/arm_ffa/common.h

> new file mode 100644

> index 000000000000..fc6948efe9f3

> --- /dev/null

> +++ b/drivers/firmware/arm_ffa/common.h

> @@ -0,0 +1,26 @@

> +/* SPDX-License-Identifier: GPL-2.0 */

> +/*

> + * Copyright (C) 2020 ARM Ltd.

> + */

> +

> +#ifndef _FFA_COMMON_H

> +#define _FFA_COMMON_H

> +

> +#include <linux/arm-smccc.h>

> +#include <linux/err.h>

> +

> +typedef struct arm_smccc_v1_2_res ffa_res_t;

> +

> +typedef ffa_res_t

> +(ffa_fn)(unsigned long, unsigned long, unsigned long, unsigned long,

> +	 unsigned long, unsigned long, unsigned long, unsigned long);

> +

> +int __init arm_ffa_bus_init(void);

> +void __exit arm_ffa_bus_exit(void);

> +

> +static inline int __init ffa_transport_init(ffa_fn **invoke_ffa_fn)

> +{

> +	return -EOPNOTSUPP;

> +}

> +

> +#endif /* _FFA_COMMON_H */

> diff --git a/drivers/firmware/arm_ffa/driver.c b/drivers/firmware/arm_ffa/driver.c

> new file mode 100644

> index 000000000000..334dfe7102fa

> --- /dev/null

> +++ b/drivers/firmware/arm_ffa/driver.c

> @@ -0,0 +1,297 @@

> +// SPDX-License-Identifier: GPL-2.0-only

> +/*

> + * Arm Firmware Framework for ARMv8-A(FFA) interface driver

> + *

> + * The Arm FFA specification[1] describes a software architecture to

> + * leverages the virtualization extension to isolate software images

> + * provided by an ecosystem of vendors from each other and describes

> + * interfaces that standardize communication between the various software

> + * images including communication between images in the Secure world and

> + * Normal world. Any Hypervisor could use the FFA interfaces to enable

> + * communication between VMs it manages.

> + *

> + * The Hypervisor a.k.a Partition managers in FFA terminology can assign

> + * system resources(Memory regions, Devices, CPU cycles) to the partitions

> + * and manage isolation amongst them.

> + *

> + * [1] https://developer.arm.com/docs/den0077/latest

> + *

> + * Copyright (C) 2020 Arm Ltd.

> + */

> +

> +#define DRIVER_NAME "ARM FF-A"

> +#define pr_fmt(fmt) DRIVER_NAME ": " fmt

> +

> +#include <linux/arm_ffa.h>

> +#include <linux/bitfield.h>

> +#include <linux/io.h>

> +#include <linux/module.h>

> +#include <linux/slab.h>

> +

> +#include "common.h"

> +

> +#define FFA_DRIVER_VERSION	FFA_VERSION_1_0

> +

> +#define FFA_SMC(calling_convention, func_num)				\

> +	ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, (calling_convention),	\

> +			   ARM_SMCCC_OWNER_STANDARD, (func_num))

> +

> +#define FFA_SMC_32(func_num)	FFA_SMC(ARM_SMCCC_SMC_32, (func_num))

> +#define FFA_SMC_64(func_num)	FFA_SMC(ARM_SMCCC_SMC_64, (func_num))

> +

> +#define FFA_ERROR			FFA_SMC_32(0x60)

> +#define FFA_SUCCESS			FFA_SMC_32(0x61)

> +#define FFA_INTERRUPT			FFA_SMC_32(0x62)

> +#define FFA_VERSION			FFA_SMC_32(0x63)

> +#define FFA_FEATURES			FFA_SMC_32(0x64)

> +#define FFA_RX_RELEASE			FFA_SMC_32(0x65)

> +#define FFA_RXTX_MAP			FFA_SMC_32(0x66)

> +#define FFA_RXTX_UNMAP			FFA_SMC_32(0x67)

> +#define FFA_PARTITION_INFO_GET		FFA_SMC_32(0x68)

> +#define FFA_ID_GET			FFA_SMC_32(0x69)

> +#define FFA_MSG_POLL			FFA_SMC_32(0x6A)

> +#define FFA_MSG_WAIT			FFA_SMC_32(0x6B)

> +#define FFA_YIELD			FFA_SMC_32(0x6C)

> +#define FFA_RUN				FFA_SMC_32(0x6D)

> +#define FFA_MSG_SEND			FFA_SMC_32(0x6E)

> +#define FFA_MSG_SEND_DIRECT_REQ		FFA_SMC_32(0x6F)

> +#define FFA_FN64_MSG_SEND_DIRECT_REQ	FFA_SMC_64(0x6F)

> +#define FFA_MSG_SEND_DIRECT_RESP	FFA_SMC_32(0x70)

> +#define FFA_FN64_MSG_SEND_DIRECT_RESP	FFA_SMC_64(0x70)

> +#define FFA_MEM_DONATE			FFA_SMC_32(0x71)

> +#define FFA_FN64_MEM_DONATE		FFA_SMC_64(0x71)

> +#define FFA_MEM_LEND			FFA_SMC_32(0x72)

> +#define FFA_FN64_MEM_LEND		FFA_SMC_64(0x72)

> +#define FFA_MEM_SHARE			FFA_SMC_32(0x73)

> +#define FFA_FN64_MEM_SHARE		FFA_SMC_64(0x73)

> +#define FFA_MEM_RETRIEVE_REQ		FFA_SMC_32(0x74)

> +#define FFA_FN64_MEM_RETRIEVE_REQ	FFA_SMC_64(0x74)

> +#define FFA_MEM_RETRIEVE_RESP		FFA_SMC_32(0x75)

> +#define FFA_MEM_RELINQUISH		FFA_SMC_32(0x76)

> +#define FFA_MEM_RECLAIM			FFA_SMC_32(0x77)

> +#define FFA_MEM_OP_PAUSE		FFA_SMC_32(0x78)

> +#define FFA_MEM_OP_RESUME		FFA_SMC_32(0x79)

> +#define FFA_MEM_FRAG_RX			FFA_SMC_32(0x7A)

> +#define FFA_MEM_FRAG_TX			FFA_SMC_32(0x7B)

> +#define FFA_NORMAL_WORLD_RESUME		FFA_SMC_32(0x7C)

> +

> +/*

> + * For some calls it is necessary to use SMC64 to pass or return 64-bit values.

> + * For such calls FFA_FN_NATIVE(name) will choose the appropriate

> + * (native-width) function ID.

> + */

> +#ifdef CONFIG_64BIT

> +#define FFA_FN_NATIVE(name)	FFA_FN64_##name

> +#else

> +#define FFA_FN_NATIVE(name)	FFA_##name

> +#endif

> +

> +/* FFA error codes. */

> +#define FFA_RET_SUCCESS            (0)

> +#define FFA_RET_NOT_SUPPORTED      (-1)

> +#define FFA_RET_INVALID_PARAMETERS (-2)

> +#define FFA_RET_NO_MEMORY          (-3)

> +#define FFA_RET_BUSY               (-4)

> +#define FFA_RET_INTERRUPTED        (-5)

> +#define FFA_RET_DENIED             (-6)

> +#define FFA_RET_RETRY              (-7)

> +#define FFA_RET_ABORTED            (-8)

> +

> +#define MAJOR_VERSION_MASK	GENMASK(30, 16)

> +#define MINOR_VERSION_MASK	GENMASK(15, 0)

> +#define MAJOR_VERSION(x)	(u16)(FIELD_GET(MAJOR_VERSION_MASK, (x)))

> +#define MINOR_VERSION(x)	(u16)(FIELD_GET(MINOR_VERSION_MASK, (x)))

> +#define PACK_VERSION_INFO(major, minor)			\

> +	(FIELD_PREP(MAJOR_VERSION_MASK, (major)) |	\

> +	 FIELD_PREP(MINOR_VERSION_MASK, (minor)))

> +#define FFA_VERSION_1_0		PACK_VERSION_INFO(1, 0)

> +#define FFA_MIN_VERSION		FFA_VERSION_1_0

> +

> +#define SENDER_ID_MASK		GENMASK(31, 16)

> +#define RECEIVER_ID_MASK	GENMASK(15, 0)

> +#define SENDER_ID(x)		(u16)(FIELD_GET(SENDER_ID_MASK, (x)))

> +#define RECEIVER_ID(x)		(u16)(FIELD_GET(RECEIVER_ID_MASK, (x)))

> +#define PACK_TARGET_INFO(s, r)		\

> +	(FIELD_PREP(SENDER_ID_MASK, (s)) | FIELD_PREP(RECEIVER_ID_MASK, (r)))

> +

> +/**

> + * FF-A specification mentions explicitly about '4K pages'. This should

> + * not be confused with the kernel PAGE_SIZE, which is the translation

> + * granule kernel is configured and may be one among 4K, 16K and 64K.

> + */

> +#define FFA_PAGE_SIZE		SZ_4K

> +/*

> + * Keeping RX TX buffer size as 4K for now

> + * 64K may be preferred to keep it min a page in 64K PAGE_SIZE config

> + */

> +#define RXTX_BUFFER_SIZE	SZ_4K

> +

> +static ffa_fn *invoke_ffa_fn;

> +

> +static const int ffa_linux_errmap[] = {

> +	/* better than switch case as long as return value is continuous */

> +	0,		/* FFA_RET_SUCCESS */

> +	-EOPNOTSUPP,	/* FFA_RET_NOT_SUPPORTED */

> +	-EINVAL,	/* FFA_RET_INVALID_PARAMETERS */

> +	-ENOMEM,	/* FFA_RET_NO_MEMORY */

> +	-EBUSY,		/* FFA_RET_BUSY */

> +	-EINTR,		/* FFA_RET_INTERRUPTED */

> +	-EACCES,	/* FFA_RET_DENIED */

> +	-EAGAIN,	/* FFA_RET_RETRY */

> +	-ECANCELED,	/* FFA_RET_ABORTED */

> +};

> +

> +static inline int ffa_to_linux_errno(int errno)

> +{

> +	if (errno < FFA_RET_SUCCESS && errno >= -ARRAY_SIZE(ffa_linux_errmap))

> +		return ffa_linux_errmap[-errno];

> +	return -EINVAL;

> +}

> +

> +struct ffa_drv_info {

> +	u32 version;

> +	u16 vm_id;

> +	struct mutex rx_lock; /* lock to protect Rx buffer */

> +	struct mutex tx_lock; /* lock to protect Tx buffer */

> +	void *rx_buffer;

> +	void *tx_buffer;

> +};

> +

> +static struct ffa_drv_info *drv_info;

> +

> +static int ffa_version_check(u32 *version)

> +{

> +	ffa_res_t ver;

> +

> +	ver = invoke_ffa_fn(FFA_VERSION, FFA_DRIVER_VERSION, 0, 0, 0, 0, 0, 0);

> +

> +	if (ver.a0 == FFA_RET_NOT_SUPPORTED) {

> +		pr_info("FFA_VERSION returned not supported\n");

> +		return -EOPNOTSUPP;

> +	}

> +

> +	if (ver.a0 < FFA_MIN_VERSION || ver.a0 > FFA_DRIVER_VERSION) {

> +		pr_err("Incompatible version %d.%d found\n",

> +		       MAJOR_VERSION(ver.a0), MINOR_VERSION(ver.a0));

> +		return -EINVAL;

> +	}

> +

> +	*version = ver.a0;

> +	pr_info("Version %d.%d found\n", MAJOR_VERSION(ver.a0),

> +		MINOR_VERSION(ver.a0));

> +	return 0;

> +}

> +

> +static int ffa_rxtx_map(phys_addr_t tx_buf, phys_addr_t rx_buf, u32 pg_cnt)

> +{

> +	ffa_res_t ret;

> +

> +	ret = invoke_ffa_fn(FFA_RXTX_MAP, tx_buf, rx_buf, pg_cnt, 0, 0, 0, 0);


I believe this is one of the cases where 64-bit calling convention might
be needed so a FFA_FN_NATIVE(RXTX_MAP) should be used instead.

> +

> +	if (ret.a0 == FFA_ERROR)

> +		return ffa_to_linux_errno((int)ret.a2);

> +

> +	return 0;

> +}

> +

> +static int ffa_rxtx_unmap(u16 vm_id)

> +{

> +	ffa_res_t ret;

> +

> +	ret = invoke_ffa_fn(FFA_RXTX_UNMAP, vm_id, 0, 0, 0, 0, 0, 0);


The vm_id should be passed in the upper 16 bits of the 32-bit word with
the lower 16 bits set to zero.


Cheers,
Jens

> +

> +	if (ret.a0 == FFA_ERROR)

> +		return ffa_to_linux_errno((int)ret.a2);

> +

> +	return 0;

> +}

> +

> +#define VM_ID_MASK	GENMASK(15, 0)

> +static int ffa_id_get(u16 *vm_id)

> +{

> +	ffa_res_t id;

> +

> +	id = invoke_ffa_fn(FFA_ID_GET, 0, 0, 0, 0, 0, 0, 0);

> +

> +	if (id.a0 == FFA_ERROR)

> +		return ffa_to_linux_errno((int)id.a2);

> +

> +	*vm_id = FIELD_GET(VM_ID_MASK, (id.a2));

> +

> +	return 0;

> +}

> +

> +static int __init ffa_init(void)

> +{

> +	int ret;

> +

> +	ret = arm_ffa_bus_init();

> +	if (ret)

> +		return ret;

> +

> +	ret = ffa_transport_init(&invoke_ffa_fn);

> +	if (ret)

> +		return ret;

> +

> +	drv_info = kzalloc(sizeof(*drv_info), GFP_KERNEL);

> +	if (!drv_info)

> +		return -ENOMEM;

> +

> +	ret = ffa_version_check(&drv_info->version);

> +	if (ret)

> +		goto free_drv_info;

> +

> +	if (ffa_id_get(&drv_info->vm_id)) {

> +		pr_err("failed to obtain VM id for self\n");

> +		ret = -ENODEV;

> +		goto free_drv_info;

> +	}

> +

> +	drv_info->rx_buffer = alloc_pages_exact(RXTX_BUFFER_SIZE, GFP_KERNEL);

> +	if (!drv_info->rx_buffer) {

> +		ret = -ENOMEM;

> +		goto free_pages;

> +	}

> +

> +	drv_info->tx_buffer = alloc_pages_exact(RXTX_BUFFER_SIZE, GFP_KERNEL);

> +	if (!drv_info->tx_buffer) {

> +		ret = -ENOMEM;

> +		goto free_pages;

> +	}

> +

> +	ret = ffa_rxtx_map(virt_to_phys(drv_info->tx_buffer),

> +			   virt_to_phys(drv_info->rx_buffer),

> +			   RXTX_BUFFER_SIZE / FFA_PAGE_SIZE);

> +	if (ret) {

> +		pr_err("failed to register FFA RxTx buffers\n");

> +		goto free_pages;

> +	}

> +

> +	mutex_init(&drv_info->rx_lock);

> +	mutex_init(&drv_info->tx_lock);

> +

> +	return 0;

> +free_pages:

> +	if (drv_info->tx_buffer)

> +		free_pages_exact(drv_info->tx_buffer, RXTX_BUFFER_SIZE);

> +	free_pages_exact(drv_info->rx_buffer, RXTX_BUFFER_SIZE);

> +free_drv_info:

> +	kfree(drv_info);

> +	return ret;

> +}

> +module_init(ffa_init);

> +

> +static void __exit ffa_exit(void)

> +{

> +	ffa_rxtx_unmap(drv_info->vm_id);

> +	free_pages_exact(drv_info->tx_buffer, RXTX_BUFFER_SIZE);

> +	free_pages_exact(drv_info->rx_buffer, RXTX_BUFFER_SIZE);

> +	kfree(drv_info);

> +	arm_ffa_bus_exit();

> +}

> +module_exit(ffa_exit);

> +

> +MODULE_ALIAS("arm-ffa");

> +MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");

> +MODULE_DESCRIPTION("Arm FF-A interface driver");

> +MODULE_LICENSE("GPL v2");

> -- 

> 2.25.1

>
Sudeep Holla March 23, 2021, 9:53 a.m. UTC | #2
On Fri, Mar 19, 2021 at 08:25:23AM +0100, Jens Wiklander wrote:
> On Fri, Feb 12, 2021 at 03:46:11PM +0000, Sudeep Holla wrote:

> > This just add a basic driver that sets up the transport(e.g. SMCCC),

> > checks the FFA version implemented, get the partition ID for self and

> > sets up the Tx/Rx buffers for communication.

> > 

> > Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

> > ---

> >  drivers/firmware/arm_ffa/Makefile |   3 +-

> >  drivers/firmware/arm_ffa/bus.c    |  14 +-

> >  drivers/firmware/arm_ffa/common.h |  26 +++

> >  drivers/firmware/arm_ffa/driver.c | 297 ++++++++++++++++++++++++++++++

> >  4 files changed, 329 insertions(+), 11 deletions(-)

> >  create mode 100644 drivers/firmware/arm_ffa/common.h

> >  create mode 100644 drivers/firmware/arm_ffa/driver.c

> > 

> > diff --git a/drivers/firmware/arm_ffa/Makefile b/drivers/firmware/arm_ffa/Makefile

> > index bfe4323a8784..82d0d35c5324 100644

> > --- a/drivers/firmware/arm_ffa/Makefile

> > +++ b/drivers/firmware/arm_ffa/Makefile

> > @@ -1,4 +1,5 @@

> >  # SPDX-License-Identifier: GPL-2.0-only

> >  ffa-bus-y = bus.o

> > -ffa-module-objs := $(ffa-bus-y)

> > +ffa-driver-y = driver.o

> > +ffa-module-objs := $(ffa-bus-y) $(ffa-driver-y)

> >  obj-$(CONFIG_ARM_FFA_TRANSPORT) = ffa-module.o

> > diff --git a/drivers/firmware/arm_ffa/bus.c b/drivers/firmware/arm_ffa/bus.c

> > index 3b01a3586f7b..9debdc87111c 100644

> > --- a/drivers/firmware/arm_ffa/bus.c

> > +++ b/drivers/firmware/arm_ffa/bus.c

> > @@ -13,6 +13,8 @@

> >  #include <linux/slab.h>

> >  #include <linux/types.h>

> >  

> > +#include "common.h"

> > +

> >  static int ffa_device_match(struct device *dev, struct device_driver *drv)

> >  {

> >  	const struct ffa_device_id *id_table;

> > @@ -167,21 +169,13 @@ void ffa_device_unregister(struct ffa_device *ffa_dev)

> >  }

> >  EXPORT_SYMBOL_GPL(ffa_device_unregister);

> >  

> > -static int __init arm_ffa_bus_init(void)

> > +int __init arm_ffa_bus_init(void)

> >  {

> >  	return bus_register(&ffa_bus_type);

> >  }

> > -module_init(arm_ffa_bus_init);

> >  

> > -static void __exit arm_ffa_bus_exit(void)

> > +void __exit arm_ffa_bus_exit(void)

> >  {

> >  	ffa_devices_unregister();

> >  	bus_unregister(&ffa_bus_type);

> >  }

> > -

> > -module_exit(arm_ffa_bus_exit);

> > -

> > -MODULE_ALIAS("arm-ffa-bus");

> > -MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");

> > -MODULE_DESCRIPTION("Arm FF-A bus driver");

> > -MODULE_LICENSE("GPL v2");

> > diff --git a/drivers/firmware/arm_ffa/common.h b/drivers/firmware/arm_ffa/common.h

> > new file mode 100644

> > index 000000000000..fc6948efe9f3

> > --- /dev/null

> > +++ b/drivers/firmware/arm_ffa/common.h

> > @@ -0,0 +1,26 @@

> > +/* SPDX-License-Identifier: GPL-2.0 */

> > +/*

> > + * Copyright (C) 2020 ARM Ltd.

> > + */

> > +

> > +#ifndef _FFA_COMMON_H

> > +#define _FFA_COMMON_H

> > +

> > +#include <linux/arm-smccc.h>

> > +#include <linux/err.h>

> > +

> > +typedef struct arm_smccc_v1_2_res ffa_res_t;

> > +

> > +typedef ffa_res_t

> > +(ffa_fn)(unsigned long, unsigned long, unsigned long, unsigned long,

> > +	 unsigned long, unsigned long, unsigned long, unsigned long);

> > +

> > +int __init arm_ffa_bus_init(void);

> > +void __exit arm_ffa_bus_exit(void);

> > +

> > +static inline int __init ffa_transport_init(ffa_fn **invoke_ffa_fn)

> > +{

> > +	return -EOPNOTSUPP;

> > +}

> > +

> > +#endif /* _FFA_COMMON_H */

> > diff --git a/drivers/firmware/arm_ffa/driver.c b/drivers/firmware/arm_ffa/driver.c

> > new file mode 100644

> > index 000000000000..334dfe7102fa

> > --- /dev/null

> > +++ b/drivers/firmware/arm_ffa/driver.c

> > @@ -0,0 +1,297 @@

> > +// SPDX-License-Identifier: GPL-2.0-only

> > +/*

> > + * Arm Firmware Framework for ARMv8-A(FFA) interface driver

> > + *

> > + * The Arm FFA specification[1] describes a software architecture to

> > + * leverages the virtualization extension to isolate software images

> > + * provided by an ecosystem of vendors from each other and describes

> > + * interfaces that standardize communication between the various software

> > + * images including communication between images in the Secure world and

> > + * Normal world. Any Hypervisor could use the FFA interfaces to enable

> > + * communication between VMs it manages.

> > + *

> > + * The Hypervisor a.k.a Partition managers in FFA terminology can assign

> > + * system resources(Memory regions, Devices, CPU cycles) to the partitions

> > + * and manage isolation amongst them.

> > + *

> > + * [1] https://developer.arm.com/docs/den0077/latest

> > + *

> > + * Copyright (C) 2020 Arm Ltd.

> > + */

> > +

> > +#define DRIVER_NAME "ARM FF-A"

> > +#define pr_fmt(fmt) DRIVER_NAME ": " fmt

> > +

> > +#include <linux/arm_ffa.h>

> > +#include <linux/bitfield.h>

> > +#include <linux/io.h>

> > +#include <linux/module.h>

> > +#include <linux/slab.h>

> > +

> > +#include "common.h"

> > +

> > +#define FFA_DRIVER_VERSION	FFA_VERSION_1_0

> > +

> > +#define FFA_SMC(calling_convention, func_num)				\

> > +	ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, (calling_convention),	\

> > +			   ARM_SMCCC_OWNER_STANDARD, (func_num))

> > +

> > +#define FFA_SMC_32(func_num)	FFA_SMC(ARM_SMCCC_SMC_32, (func_num))

> > +#define FFA_SMC_64(func_num)	FFA_SMC(ARM_SMCCC_SMC_64, (func_num))

> > +

> > +#define FFA_ERROR			FFA_SMC_32(0x60)

> > +#define FFA_SUCCESS			FFA_SMC_32(0x61)

> > +#define FFA_INTERRUPT			FFA_SMC_32(0x62)

> > +#define FFA_VERSION			FFA_SMC_32(0x63)

> > +#define FFA_FEATURES			FFA_SMC_32(0x64)

> > +#define FFA_RX_RELEASE			FFA_SMC_32(0x65)

> > +#define FFA_RXTX_MAP			FFA_SMC_32(0x66)

> > +#define FFA_RXTX_UNMAP			FFA_SMC_32(0x67)

> > +#define FFA_PARTITION_INFO_GET		FFA_SMC_32(0x68)

> > +#define FFA_ID_GET			FFA_SMC_32(0x69)

> > +#define FFA_MSG_POLL			FFA_SMC_32(0x6A)

> > +#define FFA_MSG_WAIT			FFA_SMC_32(0x6B)

> > +#define FFA_YIELD			FFA_SMC_32(0x6C)

> > +#define FFA_RUN				FFA_SMC_32(0x6D)

> > +#define FFA_MSG_SEND			FFA_SMC_32(0x6E)

> > +#define FFA_MSG_SEND_DIRECT_REQ		FFA_SMC_32(0x6F)

> > +#define FFA_FN64_MSG_SEND_DIRECT_REQ	FFA_SMC_64(0x6F)

> > +#define FFA_MSG_SEND_DIRECT_RESP	FFA_SMC_32(0x70)

> > +#define FFA_FN64_MSG_SEND_DIRECT_RESP	FFA_SMC_64(0x70)

> > +#define FFA_MEM_DONATE			FFA_SMC_32(0x71)

> > +#define FFA_FN64_MEM_DONATE		FFA_SMC_64(0x71)

> > +#define FFA_MEM_LEND			FFA_SMC_32(0x72)

> > +#define FFA_FN64_MEM_LEND		FFA_SMC_64(0x72)

> > +#define FFA_MEM_SHARE			FFA_SMC_32(0x73)

> > +#define FFA_FN64_MEM_SHARE		FFA_SMC_64(0x73)

> > +#define FFA_MEM_RETRIEVE_REQ		FFA_SMC_32(0x74)

> > +#define FFA_FN64_MEM_RETRIEVE_REQ	FFA_SMC_64(0x74)

> > +#define FFA_MEM_RETRIEVE_RESP		FFA_SMC_32(0x75)

> > +#define FFA_MEM_RELINQUISH		FFA_SMC_32(0x76)

> > +#define FFA_MEM_RECLAIM			FFA_SMC_32(0x77)

> > +#define FFA_MEM_OP_PAUSE		FFA_SMC_32(0x78)

> > +#define FFA_MEM_OP_RESUME		FFA_SMC_32(0x79)

> > +#define FFA_MEM_FRAG_RX			FFA_SMC_32(0x7A)

> > +#define FFA_MEM_FRAG_TX			FFA_SMC_32(0x7B)

> > +#define FFA_NORMAL_WORLD_RESUME		FFA_SMC_32(0x7C)

> > +

> > +/*

> > + * For some calls it is necessary to use SMC64 to pass or return 64-bit values.

> > + * For such calls FFA_FN_NATIVE(name) will choose the appropriate

> > + * (native-width) function ID.

> > + */

> > +#ifdef CONFIG_64BIT

> > +#define FFA_FN_NATIVE(name)	FFA_FN64_##name

> > +#else

> > +#define FFA_FN_NATIVE(name)	FFA_##name

> > +#endif

> > +

> > +/* FFA error codes. */

> > +#define FFA_RET_SUCCESS            (0)

> > +#define FFA_RET_NOT_SUPPORTED      (-1)

> > +#define FFA_RET_INVALID_PARAMETERS (-2)

> > +#define FFA_RET_NO_MEMORY          (-3)

> > +#define FFA_RET_BUSY               (-4)

> > +#define FFA_RET_INTERRUPTED        (-5)

> > +#define FFA_RET_DENIED             (-6)

> > +#define FFA_RET_RETRY              (-7)

> > +#define FFA_RET_ABORTED            (-8)

> > +

> > +#define MAJOR_VERSION_MASK	GENMASK(30, 16)

> > +#define MINOR_VERSION_MASK	GENMASK(15, 0)

> > +#define MAJOR_VERSION(x)	(u16)(FIELD_GET(MAJOR_VERSION_MASK, (x)))

> > +#define MINOR_VERSION(x)	(u16)(FIELD_GET(MINOR_VERSION_MASK, (x)))

> > +#define PACK_VERSION_INFO(major, minor)			\

> > +	(FIELD_PREP(MAJOR_VERSION_MASK, (major)) |	\

> > +	 FIELD_PREP(MINOR_VERSION_MASK, (minor)))

> > +#define FFA_VERSION_1_0		PACK_VERSION_INFO(1, 0)

> > +#define FFA_MIN_VERSION		FFA_VERSION_1_0

> > +

> > +#define SENDER_ID_MASK		GENMASK(31, 16)

> > +#define RECEIVER_ID_MASK	GENMASK(15, 0)

> > +#define SENDER_ID(x)		(u16)(FIELD_GET(SENDER_ID_MASK, (x)))

> > +#define RECEIVER_ID(x)		(u16)(FIELD_GET(RECEIVER_ID_MASK, (x)))

> > +#define PACK_TARGET_INFO(s, r)		\

> > +	(FIELD_PREP(SENDER_ID_MASK, (s)) | FIELD_PREP(RECEIVER_ID_MASK, (r)))

> > +

> > +/**

> > + * FF-A specification mentions explicitly about '4K pages'. This should

> > + * not be confused with the kernel PAGE_SIZE, which is the translation

> > + * granule kernel is configured and may be one among 4K, 16K and 64K.

> > + */

> > +#define FFA_PAGE_SIZE		SZ_4K

> > +/*

> > + * Keeping RX TX buffer size as 4K for now

> > + * 64K may be preferred to keep it min a page in 64K PAGE_SIZE config

> > + */

> > +#define RXTX_BUFFER_SIZE	SZ_4K

> > +

> > +static ffa_fn *invoke_ffa_fn;

> > +

> > +static const int ffa_linux_errmap[] = {

> > +	/* better than switch case as long as return value is continuous */

> > +	0,		/* FFA_RET_SUCCESS */

> > +	-EOPNOTSUPP,	/* FFA_RET_NOT_SUPPORTED */

> > +	-EINVAL,	/* FFA_RET_INVALID_PARAMETERS */

> > +	-ENOMEM,	/* FFA_RET_NO_MEMORY */

> > +	-EBUSY,		/* FFA_RET_BUSY */

> > +	-EINTR,		/* FFA_RET_INTERRUPTED */

> > +	-EACCES,	/* FFA_RET_DENIED */

> > +	-EAGAIN,	/* FFA_RET_RETRY */

> > +	-ECANCELED,	/* FFA_RET_ABORTED */

> > +};

> > +

> > +static inline int ffa_to_linux_errno(int errno)

> > +{

> > +	if (errno < FFA_RET_SUCCESS && errno >= -ARRAY_SIZE(ffa_linux_errmap))

> > +		return ffa_linux_errmap[-errno];

> > +	return -EINVAL;

> > +}

> > +

> > +struct ffa_drv_info {

> > +	u32 version;

> > +	u16 vm_id;

> > +	struct mutex rx_lock; /* lock to protect Rx buffer */

> > +	struct mutex tx_lock; /* lock to protect Tx buffer */

> > +	void *rx_buffer;

> > +	void *tx_buffer;

> > +};

> > +

> > +static struct ffa_drv_info *drv_info;

> > +

> > +static int ffa_version_check(u32 *version)

> > +{

> > +	ffa_res_t ver;

> > +

> > +	ver = invoke_ffa_fn(FFA_VERSION, FFA_DRIVER_VERSION, 0, 0, 0, 0, 0, 0);

> > +

> > +	if (ver.a0 == FFA_RET_NOT_SUPPORTED) {

> > +		pr_info("FFA_VERSION returned not supported\n");

> > +		return -EOPNOTSUPP;

> > +	}

> > +

> > +	if (ver.a0 < FFA_MIN_VERSION || ver.a0 > FFA_DRIVER_VERSION) {

> > +		pr_err("Incompatible version %d.%d found\n",

> > +		       MAJOR_VERSION(ver.a0), MINOR_VERSION(ver.a0));

> > +		return -EINVAL;

> > +	}

> > +

> > +	*version = ver.a0;

> > +	pr_info("Version %d.%d found\n", MAJOR_VERSION(ver.a0),

> > +		MINOR_VERSION(ver.a0));

> > +	return 0;

> > +}

> > +

> > +static int ffa_rxtx_map(phys_addr_t tx_buf, phys_addr_t rx_buf, u32 pg_cnt)

> > +{

> > +	ffa_res_t ret;

> > +

> > +	ret = invoke_ffa_fn(FFA_RXTX_MAP, tx_buf, rx_buf, pg_cnt, 0, 0, 0, 0);

> 

> I believe this is one of the cases where 64-bit calling convention might

> be needed so a FFA_FN_NATIVE(RXTX_MAP) should be used instead.

>


Indeed, missed that completely. Thanks for spotting it.

> > +

> > +	if (ret.a0 == FFA_ERROR)

> > +		return ffa_to_linux_errno((int)ret.a2);

> > +

> > +	return 0;

> > +}

> > +

> > +static int ffa_rxtx_unmap(u16 vm_id)

> > +{

> > +	ffa_res_t ret;

> > +

> > +	ret = invoke_ffa_fn(FFA_RXTX_UNMAP, vm_id, 0, 0, 0, 0, 0, 0);

> 

> The vm_id should be passed in the upper 16 bits of the 32-bit word with

> the lower 16 bits set to zero.

> 


Good catch, will fix it.

-- 
Regards,
Sudeep
diff mbox series

Patch

diff --git a/drivers/firmware/arm_ffa/Makefile b/drivers/firmware/arm_ffa/Makefile
index bfe4323a8784..82d0d35c5324 100644
--- a/drivers/firmware/arm_ffa/Makefile
+++ b/drivers/firmware/arm_ffa/Makefile
@@ -1,4 +1,5 @@ 
 # SPDX-License-Identifier: GPL-2.0-only
 ffa-bus-y = bus.o
-ffa-module-objs := $(ffa-bus-y)
+ffa-driver-y = driver.o
+ffa-module-objs := $(ffa-bus-y) $(ffa-driver-y)
 obj-$(CONFIG_ARM_FFA_TRANSPORT) = ffa-module.o
diff --git a/drivers/firmware/arm_ffa/bus.c b/drivers/firmware/arm_ffa/bus.c
index 3b01a3586f7b..9debdc87111c 100644
--- a/drivers/firmware/arm_ffa/bus.c
+++ b/drivers/firmware/arm_ffa/bus.c
@@ -13,6 +13,8 @@ 
 #include <linux/slab.h>
 #include <linux/types.h>
 
+#include "common.h"
+
 static int ffa_device_match(struct device *dev, struct device_driver *drv)
 {
 	const struct ffa_device_id *id_table;
@@ -167,21 +169,13 @@  void ffa_device_unregister(struct ffa_device *ffa_dev)
 }
 EXPORT_SYMBOL_GPL(ffa_device_unregister);
 
-static int __init arm_ffa_bus_init(void)
+int __init arm_ffa_bus_init(void)
 {
 	return bus_register(&ffa_bus_type);
 }
-module_init(arm_ffa_bus_init);
 
-static void __exit arm_ffa_bus_exit(void)
+void __exit arm_ffa_bus_exit(void)
 {
 	ffa_devices_unregister();
 	bus_unregister(&ffa_bus_type);
 }
-
-module_exit(arm_ffa_bus_exit);
-
-MODULE_ALIAS("arm-ffa-bus");
-MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
-MODULE_DESCRIPTION("Arm FF-A bus driver");
-MODULE_LICENSE("GPL v2");
diff --git a/drivers/firmware/arm_ffa/common.h b/drivers/firmware/arm_ffa/common.h
new file mode 100644
index 000000000000..fc6948efe9f3
--- /dev/null
+++ b/drivers/firmware/arm_ffa/common.h
@@ -0,0 +1,26 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020 ARM Ltd.
+ */
+
+#ifndef _FFA_COMMON_H
+#define _FFA_COMMON_H
+
+#include <linux/arm-smccc.h>
+#include <linux/err.h>
+
+typedef struct arm_smccc_v1_2_res ffa_res_t;
+
+typedef ffa_res_t
+(ffa_fn)(unsigned long, unsigned long, unsigned long, unsigned long,
+	 unsigned long, unsigned long, unsigned long, unsigned long);
+
+int __init arm_ffa_bus_init(void);
+void __exit arm_ffa_bus_exit(void);
+
+static inline int __init ffa_transport_init(ffa_fn **invoke_ffa_fn)
+{
+	return -EOPNOTSUPP;
+}
+
+#endif /* _FFA_COMMON_H */
diff --git a/drivers/firmware/arm_ffa/driver.c b/drivers/firmware/arm_ffa/driver.c
new file mode 100644
index 000000000000..334dfe7102fa
--- /dev/null
+++ b/drivers/firmware/arm_ffa/driver.c
@@ -0,0 +1,297 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Arm Firmware Framework for ARMv8-A(FFA) interface driver
+ *
+ * The Arm FFA specification[1] describes a software architecture to
+ * leverages the virtualization extension to isolate software images
+ * provided by an ecosystem of vendors from each other and describes
+ * interfaces that standardize communication between the various software
+ * images including communication between images in the Secure world and
+ * Normal world. Any Hypervisor could use the FFA interfaces to enable
+ * communication between VMs it manages.
+ *
+ * The Hypervisor a.k.a Partition managers in FFA terminology can assign
+ * system resources(Memory regions, Devices, CPU cycles) to the partitions
+ * and manage isolation amongst them.
+ *
+ * [1] https://developer.arm.com/docs/den0077/latest
+ *
+ * Copyright (C) 2020 Arm Ltd.
+ */
+
+#define DRIVER_NAME "ARM FF-A"
+#define pr_fmt(fmt) DRIVER_NAME ": " fmt
+
+#include <linux/arm_ffa.h>
+#include <linux/bitfield.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+#include "common.h"
+
+#define FFA_DRIVER_VERSION	FFA_VERSION_1_0
+
+#define FFA_SMC(calling_convention, func_num)				\
+	ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, (calling_convention),	\
+			   ARM_SMCCC_OWNER_STANDARD, (func_num))
+
+#define FFA_SMC_32(func_num)	FFA_SMC(ARM_SMCCC_SMC_32, (func_num))
+#define FFA_SMC_64(func_num)	FFA_SMC(ARM_SMCCC_SMC_64, (func_num))
+
+#define FFA_ERROR			FFA_SMC_32(0x60)
+#define FFA_SUCCESS			FFA_SMC_32(0x61)
+#define FFA_INTERRUPT			FFA_SMC_32(0x62)
+#define FFA_VERSION			FFA_SMC_32(0x63)
+#define FFA_FEATURES			FFA_SMC_32(0x64)
+#define FFA_RX_RELEASE			FFA_SMC_32(0x65)
+#define FFA_RXTX_MAP			FFA_SMC_32(0x66)
+#define FFA_RXTX_UNMAP			FFA_SMC_32(0x67)
+#define FFA_PARTITION_INFO_GET		FFA_SMC_32(0x68)
+#define FFA_ID_GET			FFA_SMC_32(0x69)
+#define FFA_MSG_POLL			FFA_SMC_32(0x6A)
+#define FFA_MSG_WAIT			FFA_SMC_32(0x6B)
+#define FFA_YIELD			FFA_SMC_32(0x6C)
+#define FFA_RUN				FFA_SMC_32(0x6D)
+#define FFA_MSG_SEND			FFA_SMC_32(0x6E)
+#define FFA_MSG_SEND_DIRECT_REQ		FFA_SMC_32(0x6F)
+#define FFA_FN64_MSG_SEND_DIRECT_REQ	FFA_SMC_64(0x6F)
+#define FFA_MSG_SEND_DIRECT_RESP	FFA_SMC_32(0x70)
+#define FFA_FN64_MSG_SEND_DIRECT_RESP	FFA_SMC_64(0x70)
+#define FFA_MEM_DONATE			FFA_SMC_32(0x71)
+#define FFA_FN64_MEM_DONATE		FFA_SMC_64(0x71)
+#define FFA_MEM_LEND			FFA_SMC_32(0x72)
+#define FFA_FN64_MEM_LEND		FFA_SMC_64(0x72)
+#define FFA_MEM_SHARE			FFA_SMC_32(0x73)
+#define FFA_FN64_MEM_SHARE		FFA_SMC_64(0x73)
+#define FFA_MEM_RETRIEVE_REQ		FFA_SMC_32(0x74)
+#define FFA_FN64_MEM_RETRIEVE_REQ	FFA_SMC_64(0x74)
+#define FFA_MEM_RETRIEVE_RESP		FFA_SMC_32(0x75)
+#define FFA_MEM_RELINQUISH		FFA_SMC_32(0x76)
+#define FFA_MEM_RECLAIM			FFA_SMC_32(0x77)
+#define FFA_MEM_OP_PAUSE		FFA_SMC_32(0x78)
+#define FFA_MEM_OP_RESUME		FFA_SMC_32(0x79)
+#define FFA_MEM_FRAG_RX			FFA_SMC_32(0x7A)
+#define FFA_MEM_FRAG_TX			FFA_SMC_32(0x7B)
+#define FFA_NORMAL_WORLD_RESUME		FFA_SMC_32(0x7C)
+
+/*
+ * For some calls it is necessary to use SMC64 to pass or return 64-bit values.
+ * For such calls FFA_FN_NATIVE(name) will choose the appropriate
+ * (native-width) function ID.
+ */
+#ifdef CONFIG_64BIT
+#define FFA_FN_NATIVE(name)	FFA_FN64_##name
+#else
+#define FFA_FN_NATIVE(name)	FFA_##name
+#endif
+
+/* FFA error codes. */
+#define FFA_RET_SUCCESS            (0)
+#define FFA_RET_NOT_SUPPORTED      (-1)
+#define FFA_RET_INVALID_PARAMETERS (-2)
+#define FFA_RET_NO_MEMORY          (-3)
+#define FFA_RET_BUSY               (-4)
+#define FFA_RET_INTERRUPTED        (-5)
+#define FFA_RET_DENIED             (-6)
+#define FFA_RET_RETRY              (-7)
+#define FFA_RET_ABORTED            (-8)
+
+#define MAJOR_VERSION_MASK	GENMASK(30, 16)
+#define MINOR_VERSION_MASK	GENMASK(15, 0)
+#define MAJOR_VERSION(x)	(u16)(FIELD_GET(MAJOR_VERSION_MASK, (x)))
+#define MINOR_VERSION(x)	(u16)(FIELD_GET(MINOR_VERSION_MASK, (x)))
+#define PACK_VERSION_INFO(major, minor)			\
+	(FIELD_PREP(MAJOR_VERSION_MASK, (major)) |	\
+	 FIELD_PREP(MINOR_VERSION_MASK, (minor)))
+#define FFA_VERSION_1_0		PACK_VERSION_INFO(1, 0)
+#define FFA_MIN_VERSION		FFA_VERSION_1_0
+
+#define SENDER_ID_MASK		GENMASK(31, 16)
+#define RECEIVER_ID_MASK	GENMASK(15, 0)
+#define SENDER_ID(x)		(u16)(FIELD_GET(SENDER_ID_MASK, (x)))
+#define RECEIVER_ID(x)		(u16)(FIELD_GET(RECEIVER_ID_MASK, (x)))
+#define PACK_TARGET_INFO(s, r)		\
+	(FIELD_PREP(SENDER_ID_MASK, (s)) | FIELD_PREP(RECEIVER_ID_MASK, (r)))
+
+/**
+ * FF-A specification mentions explicitly about '4K pages'. This should
+ * not be confused with the kernel PAGE_SIZE, which is the translation
+ * granule kernel is configured and may be one among 4K, 16K and 64K.
+ */
+#define FFA_PAGE_SIZE		SZ_4K
+/*
+ * Keeping RX TX buffer size as 4K for now
+ * 64K may be preferred to keep it min a page in 64K PAGE_SIZE config
+ */
+#define RXTX_BUFFER_SIZE	SZ_4K
+
+static ffa_fn *invoke_ffa_fn;
+
+static const int ffa_linux_errmap[] = {
+	/* better than switch case as long as return value is continuous */
+	0,		/* FFA_RET_SUCCESS */
+	-EOPNOTSUPP,	/* FFA_RET_NOT_SUPPORTED */
+	-EINVAL,	/* FFA_RET_INVALID_PARAMETERS */
+	-ENOMEM,	/* FFA_RET_NO_MEMORY */
+	-EBUSY,		/* FFA_RET_BUSY */
+	-EINTR,		/* FFA_RET_INTERRUPTED */
+	-EACCES,	/* FFA_RET_DENIED */
+	-EAGAIN,	/* FFA_RET_RETRY */
+	-ECANCELED,	/* FFA_RET_ABORTED */
+};
+
+static inline int ffa_to_linux_errno(int errno)
+{
+	if (errno < FFA_RET_SUCCESS && errno >= -ARRAY_SIZE(ffa_linux_errmap))
+		return ffa_linux_errmap[-errno];
+	return -EINVAL;
+}
+
+struct ffa_drv_info {
+	u32 version;
+	u16 vm_id;
+	struct mutex rx_lock; /* lock to protect Rx buffer */
+	struct mutex tx_lock; /* lock to protect Tx buffer */
+	void *rx_buffer;
+	void *tx_buffer;
+};
+
+static struct ffa_drv_info *drv_info;
+
+static int ffa_version_check(u32 *version)
+{
+	ffa_res_t ver;
+
+	ver = invoke_ffa_fn(FFA_VERSION, FFA_DRIVER_VERSION, 0, 0, 0, 0, 0, 0);
+
+	if (ver.a0 == FFA_RET_NOT_SUPPORTED) {
+		pr_info("FFA_VERSION returned not supported\n");
+		return -EOPNOTSUPP;
+	}
+
+	if (ver.a0 < FFA_MIN_VERSION || ver.a0 > FFA_DRIVER_VERSION) {
+		pr_err("Incompatible version %d.%d found\n",
+		       MAJOR_VERSION(ver.a0), MINOR_VERSION(ver.a0));
+		return -EINVAL;
+	}
+
+	*version = ver.a0;
+	pr_info("Version %d.%d found\n", MAJOR_VERSION(ver.a0),
+		MINOR_VERSION(ver.a0));
+	return 0;
+}
+
+static int ffa_rxtx_map(phys_addr_t tx_buf, phys_addr_t rx_buf, u32 pg_cnt)
+{
+	ffa_res_t ret;
+
+	ret = invoke_ffa_fn(FFA_RXTX_MAP, tx_buf, rx_buf, pg_cnt, 0, 0, 0, 0);
+
+	if (ret.a0 == FFA_ERROR)
+		return ffa_to_linux_errno((int)ret.a2);
+
+	return 0;
+}
+
+static int ffa_rxtx_unmap(u16 vm_id)
+{
+	ffa_res_t ret;
+
+	ret = invoke_ffa_fn(FFA_RXTX_UNMAP, vm_id, 0, 0, 0, 0, 0, 0);
+
+	if (ret.a0 == FFA_ERROR)
+		return ffa_to_linux_errno((int)ret.a2);
+
+	return 0;
+}
+
+#define VM_ID_MASK	GENMASK(15, 0)
+static int ffa_id_get(u16 *vm_id)
+{
+	ffa_res_t id;
+
+	id = invoke_ffa_fn(FFA_ID_GET, 0, 0, 0, 0, 0, 0, 0);
+
+	if (id.a0 == FFA_ERROR)
+		return ffa_to_linux_errno((int)id.a2);
+
+	*vm_id = FIELD_GET(VM_ID_MASK, (id.a2));
+
+	return 0;
+}
+
+static int __init ffa_init(void)
+{
+	int ret;
+
+	ret = arm_ffa_bus_init();
+	if (ret)
+		return ret;
+
+	ret = ffa_transport_init(&invoke_ffa_fn);
+	if (ret)
+		return ret;
+
+	drv_info = kzalloc(sizeof(*drv_info), GFP_KERNEL);
+	if (!drv_info)
+		return -ENOMEM;
+
+	ret = ffa_version_check(&drv_info->version);
+	if (ret)
+		goto free_drv_info;
+
+	if (ffa_id_get(&drv_info->vm_id)) {
+		pr_err("failed to obtain VM id for self\n");
+		ret = -ENODEV;
+		goto free_drv_info;
+	}
+
+	drv_info->rx_buffer = alloc_pages_exact(RXTX_BUFFER_SIZE, GFP_KERNEL);
+	if (!drv_info->rx_buffer) {
+		ret = -ENOMEM;
+		goto free_pages;
+	}
+
+	drv_info->tx_buffer = alloc_pages_exact(RXTX_BUFFER_SIZE, GFP_KERNEL);
+	if (!drv_info->tx_buffer) {
+		ret = -ENOMEM;
+		goto free_pages;
+	}
+
+	ret = ffa_rxtx_map(virt_to_phys(drv_info->tx_buffer),
+			   virt_to_phys(drv_info->rx_buffer),
+			   RXTX_BUFFER_SIZE / FFA_PAGE_SIZE);
+	if (ret) {
+		pr_err("failed to register FFA RxTx buffers\n");
+		goto free_pages;
+	}
+
+	mutex_init(&drv_info->rx_lock);
+	mutex_init(&drv_info->tx_lock);
+
+	return 0;
+free_pages:
+	if (drv_info->tx_buffer)
+		free_pages_exact(drv_info->tx_buffer, RXTX_BUFFER_SIZE);
+	free_pages_exact(drv_info->rx_buffer, RXTX_BUFFER_SIZE);
+free_drv_info:
+	kfree(drv_info);
+	return ret;
+}
+module_init(ffa_init);
+
+static void __exit ffa_exit(void)
+{
+	ffa_rxtx_unmap(drv_info->vm_id);
+	free_pages_exact(drv_info->tx_buffer, RXTX_BUFFER_SIZE);
+	free_pages_exact(drv_info->rx_buffer, RXTX_BUFFER_SIZE);
+	kfree(drv_info);
+	arm_ffa_bus_exit();
+}
+module_exit(ffa_exit);
+
+MODULE_ALIAS("arm-ffa");
+MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
+MODULE_DESCRIPTION("Arm FF-A interface driver");
+MODULE_LICENSE("GPL v2");