From 9dd15934f60d1298ad1c427711f338a194294a78 Mon Sep 17 00:00:00 2001 From: Sudeep Holla Date: Wed, 15 May 2024 10:40:27 +0100 Subject: firmware: arm_ffa: Move the FF-A v1.0 NULL UUID workaround to bus notifier Currently FF-A bus ffa_device_match() handles the workaround for the FF-A v1.0 devices which are not populated with UUID to match. The FF-A bus layer calls into FF-A driver and populates the device UUID if it matches with the driver attempting to match. But this forces to have both FF-A bus and core driver to be bundled into a single module. However, keep it as a single module adds problems for the FF-A driver registrations and their initcall levels. In preparation to split the FF-A bus and the core driver into distinct modules, we need to move the workaround away from the FF-A bus layer. We can add it into the FF-A core driver as a bus notifier. In order to do so, we need to always match any driver with the device if the UUID is NULL and then during the driver binding phase, we can populate the UUID if it matches with the driver UUID table using the bus notifiers. We also need to add a check for NULL UUID before calling the device/driver probe as devices with NULL UUID is possible since we match all for that case. Acked-by: Sebastian Ene Link: https://lore.kernel.org/r/20240515094028.1947976-1-sudeep.holla@arm.com Signed-off-by: Sudeep Holla --- drivers/firmware/arm_ffa/bus.c | 11 ++++++---- drivers/firmware/arm_ffa/driver.c | 45 +++++++++++++++++++++++++++++++-------- 2 files changed, 43 insertions(+), 13 deletions(-) (limited to 'drivers') diff --git a/drivers/firmware/arm_ffa/bus.c b/drivers/firmware/arm_ffa/bus.c index 2f557e90f2eb..4baaec7f0a09 100644 --- a/drivers/firmware/arm_ffa/bus.c +++ b/drivers/firmware/arm_ffa/bus.c @@ -30,12 +30,11 @@ static int ffa_device_match(struct device *dev, struct device_driver *drv) while (!uuid_is_null(&id_table->uuid)) { /* * FF-A v1.0 doesn't provide discovery of UUIDs, just the - * partition IDs, so fetch the partitions IDs for this - * id_table UUID and assign the UUID to the device if the - * partition ID matches + * partition IDs, so match it unconditionally here and handle + * it via the installed bus notifier during driver binding. */ if (uuid_is_null(&ffa_dev->uuid)) - ffa_device_match_uuid(ffa_dev, &id_table->uuid); + return 1; if (uuid_equal(&ffa_dev->uuid, &id_table->uuid)) return 1; @@ -50,6 +49,10 @@ static int ffa_device_probe(struct device *dev) struct ffa_driver *ffa_drv = to_ffa_driver(dev->driver); struct ffa_device *ffa_dev = to_ffa_dev(dev); + /* UUID can be still NULL with FF-A v1.0, so just skip probing them */ + if (uuid_is_null(&ffa_dev->uuid)) + return -ENODEV; + return ffa_drv->probe(ffa_dev); } diff --git a/drivers/firmware/arm_ffa/driver.c b/drivers/firmware/arm_ffa/driver.c index 1609247cfafc..61d514776e5b 100644 --- a/drivers/firmware/arm_ffa/driver.c +++ b/drivers/firmware/arm_ffa/driver.c @@ -1224,14 +1224,6 @@ void ffa_device_match_uuid(struct ffa_device *ffa_dev, const uuid_t *uuid) int count, idx; struct ffa_partition_info *pbuf, *tpbuf; - /* - * FF-A v1.1 provides UUID for each partition as part of the discovery - * API, the discovered UUID must be populated in the device's UUID and - * there is no need to copy the same from the driver table. - */ - if (drv_info->version > FFA_VERSION_1_0) - return; - count = ffa_partition_probe(uuid, &pbuf); if (count <= 0) return; @@ -1242,6 +1234,35 @@ void ffa_device_match_uuid(struct ffa_device *ffa_dev, const uuid_t *uuid) kfree(pbuf); } +static int +ffa_bus_notifier(struct notifier_block *nb, unsigned long action, void *data) +{ + struct device *dev = data; + struct ffa_device *fdev = to_ffa_dev(dev); + + if (action == BUS_NOTIFY_BIND_DRIVER) { + struct ffa_driver *ffa_drv = to_ffa_driver(dev->driver); + const struct ffa_device_id *id_table= ffa_drv->id_table; + + /* + * FF-A v1.1 provides UUID for each partition as part of the + * discovery API, the discovered UUID must be populated in the + * device's UUID and there is no need to workaround by copying + * the same from the driver table. + */ + if (uuid_is_null(&fdev->uuid)) + ffa_device_match_uuid(fdev, &id_table->uuid); + + return NOTIFY_OK; + } + + return NOTIFY_DONE; +} + +static struct notifier_block ffa_bus_nb = { + .notifier_call = ffa_bus_notifier, +}; + static int ffa_setup_partitions(void) { int count, idx, ret; @@ -1250,6 +1271,12 @@ static int ffa_setup_partitions(void) struct ffa_dev_part_info *info; struct ffa_partition_info *pbuf, *tpbuf; + if (drv_info->version == FFA_VERSION_1_0) { + ret = bus_register_notifier(&ffa_bus_type, &ffa_bus_nb); + if (ret) + pr_err("Failed to register FF-A bus notifiers\n"); + } + count = ffa_partition_probe(&uuid_null, &pbuf); if (count <= 0) { pr_info("%s: No partitions found, error %d\n", __func__, count); @@ -1261,7 +1288,7 @@ static int ffa_setup_partitions(void) import_uuid(&uuid, (u8 *)tpbuf->uuid); /* Note that if the UUID will be uuid_null, that will require - * ffa_device_match() to find the UUID of this partition id + * ffa_bus_notifier() to find the UUID of this partition id * with help of ffa_device_match_uuid(). FF-A v1.1 and above * provides UUID here for each partition as part of the * discovery API and the same is passed. -- cgit v1.2.3 From 18c250bd7ed0fc6917bad13560851ef0f519778d Mon Sep 17 00:00:00 2001 From: Sudeep Holla Date: Wed, 15 May 2024 10:40:28 +0100 Subject: firmware: arm_ffa: Split bus and driver into distinct modules Make the FF-A bus on its own as a distinct module initialized at subsys_initcall level when builtin. Keep the FF-A driver core stack, together with any configured transport, in a different module initialized as module_init level. FF-A drivers initialization is now changed to module_init level. Acked-by: Sebastian Ene Link: https://lore.kernel.org/r/20240515094028.1947976-2-sudeep.holla@arm.com Signed-off-by: Sudeep Holla --- drivers/firmware/arm_ffa/Makefile | 6 ++++-- drivers/firmware/arm_ffa/bus.c | 11 +++++++++-- drivers/firmware/arm_ffa/common.h | 2 -- drivers/firmware/arm_ffa/driver.c | 12 ++---------- 4 files changed, 15 insertions(+), 16 deletions(-) (limited to 'drivers') diff --git a/drivers/firmware/arm_ffa/Makefile b/drivers/firmware/arm_ffa/Makefile index 9d9f37523200..168990a7e792 100644 --- a/drivers/firmware/arm_ffa/Makefile +++ b/drivers/firmware/arm_ffa/Makefile @@ -2,5 +2,7 @@ ffa-bus-y = bus.o ffa-driver-y = driver.o ffa-transport-$(CONFIG_ARM_FFA_SMCCC) += smccc.o -ffa-module-objs := $(ffa-bus-y) $(ffa-driver-y) $(ffa-transport-y) -obj-$(CONFIG_ARM_FFA_TRANSPORT) = ffa-module.o +ffa-core-objs := $(ffa-bus-y) +ffa-module-objs := $(ffa-driver-y) $(ffa-transport-y) +obj-$(CONFIG_ARM_FFA_TRANSPORT) = ffa-core.o +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 4baaec7f0a09..0c83931485f6 100644 --- a/drivers/firmware/arm_ffa/bus.c +++ b/drivers/firmware/arm_ffa/bus.c @@ -235,14 +235,21 @@ void ffa_device_unregister(struct ffa_device *ffa_dev) } EXPORT_SYMBOL_GPL(ffa_device_unregister); -int arm_ffa_bus_init(void) +static int __init arm_ffa_bus_init(void) { return bus_register(&ffa_bus_type); } +subsys_initcall(arm_ffa_bus_init); -void arm_ffa_bus_exit(void) +static void __exit arm_ffa_bus_exit(void) { ffa_devices_unregister(); bus_unregister(&ffa_bus_type); ida_destroy(&ffa_bus_id); } +module_exit(arm_ffa_bus_exit); + +MODULE_ALIAS("ffa-core"); +MODULE_AUTHOR("Sudeep Holla "); +MODULE_DESCRIPTION("ARM FF-A bus"); +MODULE_LICENSE("GPL"); diff --git a/drivers/firmware/arm_ffa/common.h b/drivers/firmware/arm_ffa/common.h index d6eccf1fd3f6..9c6425a81d0d 100644 --- a/drivers/firmware/arm_ffa/common.h +++ b/drivers/firmware/arm_ffa/common.h @@ -14,8 +14,6 @@ typedef struct arm_smccc_1_2_regs ffa_value_t; typedef void (ffa_fn)(ffa_value_t, ffa_value_t *); -int arm_ffa_bus_init(void); -void arm_ffa_bus_exit(void); bool ffa_device_is_valid(struct ffa_device *ffa_dev); void ffa_device_match_uuid(struct ffa_device *ffa_dev, const uuid_t *uuid); diff --git a/drivers/firmware/arm_ffa/driver.c b/drivers/firmware/arm_ffa/driver.c index 61d514776e5b..7ba98c7af2e9 100644 --- a/drivers/firmware/arm_ffa/driver.c +++ b/drivers/firmware/arm_ffa/driver.c @@ -1608,14 +1608,9 @@ static int __init ffa_init(void) if (ret) return ret; - ret = arm_ffa_bus_init(); - if (ret) - return ret; - drv_info = kzalloc(sizeof(*drv_info), GFP_KERNEL); if (!drv_info) { - ret = -ENOMEM; - goto ffa_bus_exit; + return -ENOMEM; } ret = ffa_version_check(&drv_info->version); @@ -1676,11 +1671,9 @@ free_pages: free_pages_exact(drv_info->rx_buffer, RXTX_BUFFER_SIZE); free_drv_info: kfree(drv_info); -ffa_bus_exit: - arm_ffa_bus_exit(); return ret; } -subsys_initcall(ffa_init); +module_init(ffa_init); static void __exit ffa_exit(void) { @@ -1690,7 +1683,6 @@ static void __exit ffa_exit(void) 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); -- cgit v1.2.3