Hi all,
This adds support for asynchronous notifications from OP-TEE in secure world to the OP-TEE driver. This allows a design with a top half and bottom half type of driver where the top half runs in secure interrupt context and a notifications tells normal world to schedule a yielding call to do the bottom half processing.
An edge-triggered interrupt is used to notify the driver that there are asynchronous notifications pending.
Only the SMC based ABI of the OP-TEE driver gains asynchronous notifications. Future support for asynchronous notifications in the FF-A based ABI will rely on APIs which are expected to be provided by the FF-A driver in a not too distant future.
This patchset is also available at https://git.linaro.org/people/jens.wiklander/linux-tee.git/log/?h=async_noti...
v7->v8: * Fixed an error in "dt-bindings: arm: optee: add interrupt property" reported by Rob's bot. * "optee: add asynchronous notifications": - Fixed a few spell errors in comments - Added a missing optee_unregister_devices() in the cleanup path of optee_probe(). - Added Sumit's Reviewed-by
v6->v7: * Rebased on 4615e5a34b95 ("optee: add FF-A support") in https://git.kernel.org/pub/scm/linux/kernel/git/soc/soc.git with 34f3c67b8178 ("optee: smc_abi.c: add missing #include <linux/mm.h>") cherry-picked on top. This allows to resolve the conflicts with pull request "[GIT PULL] OP-TEE FF-A for V5.16" * Factored out the interrupt handling added in "optee: add asynchronous notifications" to only go into smb_abi.c. A different approach is expected with FF-A once it has asynchronous notifications. * Addressed review comments from Sumit Garg: - Replaced 0 and 1 with the macros GIC_SPI and IRQ_TYPE_EDGE_RISING in the example in the bindings. - Replaced the magic number to optee_notif_init() with OPTEE_DEFAULT_MAX_NOTIF_VALUE in the commit "optee: separate notification functions" - Switched back to tagged error path in optee_probe() - Fixed a few nits in "optee: add asynchronous notifications" - Applied Sumit's Reviewed-by on all commits but the last, "optee: add asynchronous notifications"
v5->v6: * Rebased on v5.15-rc2 * Replaced "tee: add tee_dev_open_helper() primitive" with "tee: export teedev_open() and teedev_close_context()" since it turned out that the normal teedev functions could be used instead as noted by Sumit. * Changed "optee: add asynchronous notifications" to use the exported teedev_open() and teedev_close_context() functions instead.
v4->v5: * Rebased on v5.14-rc7 * Updated documentation to clarify that one interrupt may represent multiple notifications as requested. * Applied Marc's and Rob's tags
v3->v4: * Clarfied the expected type of interrypt is edge-triggered, both in the normal documentation and in the DT bindings as requested.
v2->v3: * Rebased on v5.14-rc2 which made the patch "dt-bindings: arm: Convert optee binding to json-schema" from the V2 patch set obsolete. * Applied Ard's Acked-by on "optee: add asynchronous notifications"
v1->v2: * Added documentation * Converted optee bindings to json-schema and added interrupt property * Configure notification interrupt from DT instead of getting it from secure world, suggested by Ard Biesheuvel ardb@kernel.org.
Thanks, Jens
Jens Wiklander (6): docs: staging/tee.rst: add a section on OP-TEE notifications dt-bindings: arm: optee: add interrupt property tee: fix put order in teedev_close_context() tee: export teedev_open() and teedev_close_context() optee: separate notification functions optee: add asynchronous notifications
.../arm/firmware/linaro,optee-tz.yaml | 8 + Documentation/staging/tee.rst | 30 +++ drivers/tee/optee/Makefile | 1 + drivers/tee/optee/core.c | 2 +- drivers/tee/optee/ffa_abi.c | 6 +- drivers/tee/optee/notif.c | 125 +++++++++ drivers/tee/optee/optee_msg.h | 9 + drivers/tee/optee/optee_private.h | 28 +- drivers/tee/optee/optee_rpc_cmd.h | 31 ++- drivers/tee/optee/optee_smc.h | 75 +++++- drivers/tee/optee/rpc.c | 71 +----- drivers/tee/optee/smc_abi.c | 241 +++++++++++++++--- drivers/tee/tee_core.c | 10 +- include/linux/tee_drv.h | 14 + 14 files changed, 525 insertions(+), 126 deletions(-) create mode 100644 drivers/tee/optee/notif.c
Adds a section on notifications used by OP-TEE, synchronous and asynchronous.
Reviewed-by: Sumit Garg sumit.garg@linaro.org Acked-by: Marc Zyngier maz@kernel.org Signed-off-by: Jens Wiklander jens.wiklander@linaro.org --- Documentation/staging/tee.rst | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+)
diff --git a/Documentation/staging/tee.rst b/Documentation/staging/tee.rst index 4d4b5f889603..3c63d8dcd61e 100644 --- a/Documentation/staging/tee.rst +++ b/Documentation/staging/tee.rst @@ -184,6 +184,36 @@ order to support device enumeration. In other words, OP-TEE driver invokes this application to retrieve a list of Trusted Applications which can be registered as devices on the TEE bus.
+OP-TEE notifications +-------------------- + +There are two kinds of notifications that secure world can use to make +normal world aware of some event. + +1. Synchronous notifications delivered with ``OPTEE_RPC_CMD_NOTIFICATION`` + using the ``OPTEE_RPC_NOTIFICATION_SEND`` parameter. +2. Asynchronous notifications delivered with a combination of a non-secure + edge-triggered interrupt and a fast call from the non-secure interrupt + handler. + +Synchronous notifications are limited by depending on RPC for delivery, +this is only usable when secure world is entered with a yielding call via +``OPTEE_SMC_CALL_WITH_ARG``. This excludes such notifications from secure +world interrupt handlers. + +An asynchronous notification is delivered via a non-secure edge-triggered +interrupt to an interrupt handler registered in the OP-TEE driver. The +actual notification value are retrieved with the fast call +``OPTEE_SMC_GET_ASYNC_NOTIF_VALUE``. Note that one interrupt can represent +multiple notifications. + +One notification value ``OPTEE_SMC_ASYNC_NOTIF_VALUE_DO_BOTTOM_HALF`` has a +special meaning. When this value is received it means that normal world is +supposed to make a yielding call ``OPTEE_MSG_CMD_DO_BOTTOM_HALF``. This +call is done from the thread assisting the interrupt handler. This is a +building block for OP-TEE OS in secure world to implement the top half and +bottom half style of device drivers. + AMD-TEE driver ==============
Adds an optional interrupt property to the optee binding.
Reviewed-by: Sumit Garg sumit.garg@linaro.org Reviewed-by: Rob Herring robh@kernel.org Acked-by: Marc Zyngier maz@kernel.org Signed-off-by: Jens Wiklander jens.wiklander@linaro.org --- .../devicetree/bindings/arm/firmware/linaro,optee-tz.yaml | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/Documentation/devicetree/bindings/arm/firmware/linaro,optee-tz.yaml b/Documentation/devicetree/bindings/arm/firmware/linaro,optee-tz.yaml index c24047c1fdd5..9a426110a14a 100644 --- a/Documentation/devicetree/bindings/arm/firmware/linaro,optee-tz.yaml +++ b/Documentation/devicetree/bindings/arm/firmware/linaro,optee-tz.yaml @@ -24,6 +24,12 @@ properties: compatible: const: linaro,optee-tz
+ interrupts: + maxItems: 1 + description: | + This interrupt which is used to signal an event by the secure world + software is expected to be edge-triggered. + method: enum: [smc, hvc] description: | @@ -42,10 +48,12 @@ additionalProperties: false
examples: - | + #include <dt-bindings/interrupt-controller/arm-gic.h> firmware { optee { compatible = "linaro,optee-tz"; method = "smc"; + interrupts = <GIC_SPI 187 IRQ_TYPE_EDGE_RISING>; }; };
Prior to this patch was teedev_close_context() calling tee_device_put() before teedev_ctx_put() leading to teedev_ctx_release() accessing ctx->teedev just after the reference counter was decreased on the teedev. Fix this by calling teedev_ctx_put() before tee_device_put().
Fixes: 217e0250cccb ("tee: use reference counting for tee_context") Reviewed-by: Sumit Garg sumit.garg@linaro.org Signed-off-by: Jens Wiklander jens.wiklander@linaro.org --- drivers/tee/tee_core.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c index 2b37bc408fc3..85102d12d716 100644 --- a/drivers/tee/tee_core.c +++ b/drivers/tee/tee_core.c @@ -98,8 +98,10 @@ void teedev_ctx_put(struct tee_context *ctx)
static void teedev_close_context(struct tee_context *ctx) { - tee_device_put(ctx->teedev); + struct tee_device *teedev = ctx->teedev; + teedev_ctx_put(ctx); + tee_device_put(teedev); }
static int tee_open(struct inode *inode, struct file *filp)
Exports the two functions teedev_open() and teedev_close_context() in order to make it easier to create a driver internal struct tee_context.
Reviewed-by: Sumit Garg sumit.garg@linaro.org Signed-off-by: Jens Wiklander jens.wiklander@linaro.org --- drivers/tee/tee_core.c | 6 ++++-- include/linux/tee_drv.h | 14 ++++++++++++++ 2 files changed, 18 insertions(+), 2 deletions(-)
diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c index 85102d12d716..3fc426dad2df 100644 --- a/drivers/tee/tee_core.c +++ b/drivers/tee/tee_core.c @@ -43,7 +43,7 @@ static DEFINE_SPINLOCK(driver_lock); static struct class *tee_class; static dev_t tee_devt;
-static struct tee_context *teedev_open(struct tee_device *teedev) +struct tee_context *teedev_open(struct tee_device *teedev) { int rc; struct tee_context *ctx; @@ -70,6 +70,7 @@ static struct tee_context *teedev_open(struct tee_device *teedev) return ERR_PTR(rc);
} +EXPORT_SYMBOL_GPL(teedev_open);
void teedev_ctx_get(struct tee_context *ctx) { @@ -96,13 +97,14 @@ void teedev_ctx_put(struct tee_context *ctx) kref_put(&ctx->refcount, teedev_ctx_release); }
-static void teedev_close_context(struct tee_context *ctx) +void teedev_close_context(struct tee_context *ctx) { struct tee_device *teedev = ctx->teedev;
teedev_ctx_put(ctx); tee_device_put(teedev); } +EXPORT_SYMBOL_GPL(teedev_close_context);
static int tee_open(struct inode *inode, struct file *filp) { diff --git a/include/linux/tee_drv.h b/include/linux/tee_drv.h index a1f03461369b..468a7d83dc6c 100644 --- a/include/linux/tee_drv.h +++ b/include/linux/tee_drv.h @@ -587,4 +587,18 @@ struct tee_client_driver { #define to_tee_client_driver(d) \ container_of(d, struct tee_client_driver, driver)
+/** + * teedev_open() - Open a struct tee_device + * @teedev: Device to open + * + * @return a pointer to struct tee_context on success or an ERR_PTR on failure. + */ +struct tee_context *teedev_open(struct tee_device *teedev); + +/** + * teedev_close_context() - closes a struct tee_context + * @ctx: The struct tee_context to close + */ +void teedev_close_context(struct tee_context *ctx); + #endif /*__TEE_DRV_H*/
Renames struct optee_wait_queue to struct optee_notif and all related functions to optee_notif_*().
The implementation is changed to allow sending a notification from an atomic state, that is from the top half of an interrupt handler.
Waiting for keys is currently only used when secure world is waiting for a mutex or condition variable. The old implementation could handle any 32-bit key while this new implementation is restricted to only 8 bits or the maximum value 255. A upper value is needed since a bitmap is allocated to allow an interrupt handler to only set a bit in case the waiter hasn't had the time yet to allocate and register a completion.
The keys are currently only representing secure world threads which number usually are never even close to 255 so it should be safe for now. In future ABI updates the maximum value of the key will be communicated while the driver is initializing.
Reviewed-by: Sumit Garg sumit.garg@linaro.org Signed-off-by: Jens Wiklander jens.wiklander@linaro.org --- drivers/tee/optee/Makefile | 1 + drivers/tee/optee/core.c | 2 +- drivers/tee/optee/ffa_abi.c | 6 +- drivers/tee/optee/notif.c | 125 ++++++++++++++++++++++++++++++ drivers/tee/optee/optee_private.h | 26 +++++-- drivers/tee/optee/optee_rpc_cmd.h | 31 ++++---- drivers/tee/optee/rpc.c | 71 ++--------------- drivers/tee/optee/smc_abi.c | 10 ++- 8 files changed, 181 insertions(+), 91 deletions(-) create mode 100644 drivers/tee/optee/notif.c
diff --git a/drivers/tee/optee/Makefile b/drivers/tee/optee/Makefile index 66b8a17f14c4..a6eff388d300 100644 --- a/drivers/tee/optee/Makefile +++ b/drivers/tee/optee/Makefile @@ -2,6 +2,7 @@ obj-$(CONFIG_OPTEE) += optee.o optee-objs += core.o optee-objs += call.o +optee-objs += notif.o optee-objs += rpc.o optee-objs += supp.o optee-objs += device.o diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c index ab2edfcc6c70..ba7300ca9ddf 100644 --- a/drivers/tee/optee/core.c +++ b/drivers/tee/optee/core.c @@ -159,6 +159,7 @@ void optee_remove_common(struct optee *optee) /* Unregister OP-TEE specific client devices on TEE bus */ optee_unregister_devices();
+ optee_notif_uninit(optee); /* * The two devices have to be unregistered before we can free the * other resources. @@ -167,7 +168,6 @@ void optee_remove_common(struct optee *optee) tee_device_unregister(optee->teedev);
tee_shm_pool_free(optee->pool); - optee_wait_queue_exit(&optee->wait_queue); optee_supp_uninit(&optee->supp); mutex_destroy(&optee->call_queue.mutex); } diff --git a/drivers/tee/optee/ffa_abi.c b/drivers/tee/optee/ffa_abi.c index 6defd1ec982a..4a3e28b3270c 100644 --- a/drivers/tee/optee/ffa_abi.c +++ b/drivers/tee/optee/ffa_abi.c @@ -856,9 +856,13 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev) mutex_init(&optee->ffa.mutex); mutex_init(&optee->call_queue.mutex); INIT_LIST_HEAD(&optee->call_queue.waiters); - optee_wait_queue_init(&optee->wait_queue); optee_supp_init(&optee->supp); ffa_dev_set_drvdata(ffa_dev, optee); + rc = optee_notif_init(optee, OPTEE_DEFAULT_MAX_NOTIF_VALUE); + if (rc) { + optee_ffa_remove(ffa_dev); + return rc; + }
rc = optee_enumerate_devices(PTA_CMD_GET_DEVICES); if (rc) { diff --git a/drivers/tee/optee/notif.c b/drivers/tee/optee/notif.c new file mode 100644 index 000000000000..a28fa03dcd0e --- /dev/null +++ b/drivers/tee/optee/notif.c @@ -0,0 +1,125 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2015-2021, Linaro Limited + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/arm-smccc.h> +#include <linux/errno.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/tee_drv.h> +#include "optee_private.h" + +struct notif_entry { + struct list_head link; + struct completion c; + u_int key; +}; + +static bool have_key(struct optee *optee, u_int key) +{ + struct notif_entry *entry; + + list_for_each_entry(entry, &optee->notif.db, link) + if (entry->key == key) + return true; + + return false; +} + +int optee_notif_wait(struct optee *optee, u_int key) +{ + unsigned long flags; + struct notif_entry *entry; + int rc = 0; + + if (key > optee->notif.max_key) + return -EINVAL; + + entry = kmalloc(sizeof(*entry), GFP_KERNEL); + if (!entry) + return -ENOMEM; + init_completion(&entry->c); + entry->key = key; + + spin_lock_irqsave(&optee->notif.lock, flags); + + /* + * If the bit is already set it means that the key has already + * been posted and we must not wait. + */ + if (test_bit(key, optee->notif.bitmap)) { + clear_bit(key, optee->notif.bitmap); + goto out; + } + + /* + * Check if someone is already waiting for this key. If there is + * it's a programming error. + */ + if (have_key(optee, key)) { + rc = -EBUSY; + goto out; + } + + list_add_tail(&entry->link, &optee->notif.db); + + /* + * Unlock temporarily and wait for completion. + */ + spin_unlock_irqrestore(&optee->notif.lock, flags); + wait_for_completion(&entry->c); + spin_lock_irqsave(&optee->notif.lock, flags); + + list_del(&entry->link); +out: + spin_unlock_irqrestore(&optee->notif.lock, flags); + + kfree(entry); + + return rc; +} + +int optee_notif_send(struct optee *optee, u_int key) +{ + unsigned long flags; + struct notif_entry *entry; + + if (key > optee->notif.max_key) + return -EINVAL; + + spin_lock_irqsave(&optee->notif.lock, flags); + + list_for_each_entry(entry, &optee->notif.db, link) + if (entry->key == key) { + complete(&entry->c); + goto out; + } + + /* Only set the bit in case there where nobody waiting */ + set_bit(key, optee->notif.bitmap); +out: + spin_unlock_irqrestore(&optee->notif.lock, flags); + + return 0; +} + +int optee_notif_init(struct optee *optee, u_int max_key) +{ + spin_lock_init(&optee->notif.lock); + INIT_LIST_HEAD(&optee->notif.db); + optee->notif.bitmap = bitmap_zalloc(max_key, GFP_KERNEL); + if (!optee->notif.bitmap) + return -ENOMEM; + + optee->notif.max_key = max_key; + + return 0; +} + +void optee_notif_uninit(struct optee *optee) +{ + kfree(optee->notif.bitmap); +} diff --git a/drivers/tee/optee/optee_private.h b/drivers/tee/optee/optee_private.h index 6660e05298db..68fd28f8c6e9 100644 --- a/drivers/tee/optee/optee_private.h +++ b/drivers/tee/optee/optee_private.h @@ -28,6 +28,13 @@
#define TEEC_ORIGIN_COMMS 0x00000002
+/* + * This value should be larger than the number threads in secure world to + * meet the need from secure world. The number of threads in secure world + * are usually not even close to 255 so we should be safe for now. + */ +#define OPTEE_DEFAULT_MAX_NOTIF_VALUE 255 + typedef void (optee_invoke_fn)(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, @@ -44,10 +51,12 @@ struct optee_call_queue { struct list_head waiters; };
-struct optee_wait_queue { - /* Serializes access to this struct */ - struct mutex mu; +struct optee_notif { + u_int max_key; + /* Serializes access to the elements below in this struct */ + spinlock_t lock; struct list_head db; + u_long *bitmap; };
/** @@ -129,8 +138,7 @@ struct optee_ops { * @smc: specific to SMC ABI * @ffa: specific to FF-A ABI * @call_queue: queue of threads waiting to call @invoke_fn - * @wait_queue: queue of threads from secure world waiting for a - * secure world sync object + * @notif: notification synchronization struct * @supp: supplicant synchronization struct for RPC to supplicant * @pool: shared memory pool * @rpc_arg_count: If > 0 number of RPC parameters to make room for @@ -147,7 +155,7 @@ struct optee { struct optee_ffa ffa; }; struct optee_call_queue call_queue; - struct optee_wait_queue wait_queue; + struct optee_notif notif; struct optee_supp supp; struct tee_shm_pool *pool; unsigned int rpc_arg_count; @@ -185,8 +193,10 @@ struct optee_call_ctx { size_t num_entries; };
-void optee_wait_queue_init(struct optee_wait_queue *wq); -void optee_wait_queue_exit(struct optee_wait_queue *wq); +int optee_notif_init(struct optee *optee, u_int max_key); +void optee_notif_uninit(struct optee *optee); +int optee_notif_wait(struct optee *optee, u_int key); +int optee_notif_send(struct optee *optee, u_int key);
u32 optee_supp_thrd_req(struct tee_context *ctx, u32 func, size_t num_params, struct tee_param *param); diff --git a/drivers/tee/optee/optee_rpc_cmd.h b/drivers/tee/optee/optee_rpc_cmd.h index b8275140cef8..f3f06e0994a7 100644 --- a/drivers/tee/optee/optee_rpc_cmd.h +++ b/drivers/tee/optee/optee_rpc_cmd.h @@ -28,24 +28,27 @@ #define OPTEE_RPC_CMD_GET_TIME 3
/* - * Wait queue primitive, helper for secure world to implement a wait queue. + * Notification from/to secure world. * - * If secure world needs to wait for a secure world mutex it issues a sleep - * request instead of spinning in secure world. Conversely is a wakeup - * request issued when a secure world mutex with a thread waiting thread is - * unlocked. + * If secure world needs to wait for something, for instance a mutex, it + * does a notification wait request instead of spinning in secure world. + * Conversely can a synchronous notification can be sent when a secure + * world mutex with a thread waiting thread is unlocked. * - * Waiting on a key - * [in] value[0].a OPTEE_RPC_WAIT_QUEUE_SLEEP - * [in] value[0].b Wait key + * This interface can also be used to wait for a asynchronous notification + * which instead is sent via a non-secure interrupt. * - * Waking up a key - * [in] value[0].a OPTEE_RPC_WAIT_QUEUE_WAKEUP - * [in] value[0].b Wakeup key + * Waiting on notification + * [in] value[0].a OPTEE_RPC_NOTIFICATION_WAIT + * [in] value[0].b notification value + * + * Sending a synchronous notification + * [in] value[0].a OPTEE_RPC_NOTIFICATION_SEND + * [in] value[0].b notification value */ -#define OPTEE_RPC_CMD_WAIT_QUEUE 4 -#define OPTEE_RPC_WAIT_QUEUE_SLEEP 0 -#define OPTEE_RPC_WAIT_QUEUE_WAKEUP 1 +#define OPTEE_RPC_CMD_NOTIFICATION 4 +#define OPTEE_RPC_NOTIFICATION_WAIT 0 +#define OPTEE_RPC_NOTIFICATION_SEND 1
/* * Suspend execution diff --git a/drivers/tee/optee/rpc.c b/drivers/tee/optee/rpc.c index cd642e340eaf..e69bc6380683 100644 --- a/drivers/tee/optee/rpc.c +++ b/drivers/tee/optee/rpc.c @@ -12,23 +12,6 @@ #include "optee_private.h" #include "optee_rpc_cmd.h"
-struct wq_entry { - struct list_head link; - struct completion c; - u32 key; -}; - -void optee_wait_queue_init(struct optee_wait_queue *priv) -{ - mutex_init(&priv->mu); - INIT_LIST_HEAD(&priv->db); -} - -void optee_wait_queue_exit(struct optee_wait_queue *priv) -{ - mutex_destroy(&priv->mu); -} - static void handle_rpc_func_cmd_get_time(struct optee_msg_arg *arg) { struct timespec64 ts; @@ -144,48 +127,6 @@ static void handle_rpc_func_cmd_i2c_transfer(struct tee_context *ctx, } #endif
-static struct wq_entry *wq_entry_get(struct optee_wait_queue *wq, u32 key) -{ - struct wq_entry *w; - - mutex_lock(&wq->mu); - - list_for_each_entry(w, &wq->db, link) - if (w->key == key) - goto out; - - w = kmalloc(sizeof(*w), GFP_KERNEL); - if (w) { - init_completion(&w->c); - w->key = key; - list_add_tail(&w->link, &wq->db); - } -out: - mutex_unlock(&wq->mu); - return w; -} - -static void wq_sleep(struct optee_wait_queue *wq, u32 key) -{ - struct wq_entry *w = wq_entry_get(wq, key); - - if (w) { - wait_for_completion(&w->c); - mutex_lock(&wq->mu); - list_del(&w->link); - mutex_unlock(&wq->mu); - kfree(w); - } -} - -static void wq_wakeup(struct optee_wait_queue *wq, u32 key) -{ - struct wq_entry *w = wq_entry_get(wq, key); - - if (w) - complete(&w->c); -} - static void handle_rpc_func_cmd_wq(struct optee *optee, struct optee_msg_arg *arg) { @@ -197,11 +138,13 @@ static void handle_rpc_func_cmd_wq(struct optee *optee, goto bad;
switch (arg->params[0].u.value.a) { - case OPTEE_RPC_WAIT_QUEUE_SLEEP: - wq_sleep(&optee->wait_queue, arg->params[0].u.value.b); + case OPTEE_RPC_NOTIFICATION_WAIT: + if (optee_notif_wait(optee, arg->params[0].u.value.b)) + goto bad; break; - case OPTEE_RPC_WAIT_QUEUE_WAKEUP: - wq_wakeup(&optee->wait_queue, arg->params[0].u.value.b); + case OPTEE_RPC_NOTIFICATION_SEND: + if (optee_notif_send(optee, arg->params[0].u.value.b)) + goto bad; break; default: goto bad; @@ -319,7 +262,7 @@ void optee_rpc_cmd(struct tee_context *ctx, struct optee *optee, case OPTEE_RPC_CMD_GET_TIME: handle_rpc_func_cmd_get_time(arg); break; - case OPTEE_RPC_CMD_WAIT_QUEUE: + case OPTEE_RPC_CMD_NOTIFICATION: handle_rpc_func_cmd_wq(optee, arg); break; case OPTEE_RPC_CMD_SUSPEND: diff --git a/drivers/tee/optee/smc_abi.c b/drivers/tee/optee/smc_abi.c index 6196d7c3888f..00a7ff00a7c0 100644 --- a/drivers/tee/optee/smc_abi.c +++ b/drivers/tee/optee/smc_abi.c @@ -1288,11 +1288,17 @@ static int optee_probe(struct platform_device *pdev)
mutex_init(&optee->call_queue.mutex); INIT_LIST_HEAD(&optee->call_queue.waiters); - optee_wait_queue_init(&optee->wait_queue); optee_supp_init(&optee->supp); optee->smc.memremaped_shm = memremaped_shm; optee->pool = pool;
+ platform_set_drvdata(pdev, optee); + rc = optee_notif_init(optee, OPTEE_DEFAULT_MAX_NOTIF_VALUE); + if (rc) { + optee_remove(pdev); + return rc; + } + /* * Ensure that there are no pre-existing shm objects before enabling * the shm cache so that there's no chance of receiving an invalid @@ -1307,8 +1313,6 @@ static int optee_probe(struct platform_device *pdev) if (optee->smc.sec_caps & OPTEE_SMC_SEC_CAP_DYNAMIC_SHM) pr_info("dynamic shared memory is enabled\n");
- platform_set_drvdata(pdev, optee); - rc = optee_enumerate_devices(PTA_CMD_GET_DEVICES); if (rc) { optee_smc_remove(pdev);
Adds support for asynchronous notifications from secure world to normal world. This allows a design with a top half and bottom half type of driver where the top half runs in secure interrupt context and a notifications tells normal world to schedule a yielding call to do the bottom half processing.
The protocol is defined in optee_msg.h optee_rpc_cmd.h and optee_smc.h.
A notification consists of a 32-bit value which normal world can retrieve using a fastcall into secure world. The value OPTEE_SMC_ASYNC_NOTIF_VALUE_DO_BOTTOM_HALF (0) has a special meaning. When this value is sent it means that normal world is supposed to make a yielding call OPTEE_MSG_CMD_DO_BOTTOM_HALF.
Notification capability is negotiated while the driver is initialized. If both sides supports these notifications then they are enabled.
An interrupt is used to notify the driver that there are asynchronous notifications pending. The maximum needed notification value is communicated at this stage. This allows scaling up when needed.
Reviewed-by: Sumit Garg sumit.garg@linaro.org Acked-by: Ard Biesheuvel ardb@kernel.org Signed-off-by: Jens Wiklander jens.wiklander@linaro.org --- drivers/tee/optee/optee_msg.h | 9 ++ drivers/tee/optee/optee_private.h | 2 + drivers/tee/optee/optee_smc.h | 75 +++++++++- drivers/tee/optee/smc_abi.c | 239 +++++++++++++++++++++++++----- 4 files changed, 289 insertions(+), 36 deletions(-)
diff --git a/drivers/tee/optee/optee_msg.h b/drivers/tee/optee/optee_msg.h index 2422e185d400..70e9cc2ee96b 100644 --- a/drivers/tee/optee/optee_msg.h +++ b/drivers/tee/optee/optee_msg.h @@ -318,6 +318,13 @@ struct optee_msg_arg { * [in] param[0].u.rmem.shm_ref holds shared memory reference * [in] param[0].u.rmem.offs 0 * [in] param[0].u.rmem.size 0 + * + * OPTEE_MSG_CMD_DO_BOTTOM_HALF does the scheduled bottom half processing + * of a driver. + * + * OPTEE_MSG_CMD_STOP_ASYNC_NOTIF informs secure world that from now is + * normal world unable to process asynchronous notifications. Typically + * used when the driver is shut down. */ #define OPTEE_MSG_CMD_OPEN_SESSION 0 #define OPTEE_MSG_CMD_INVOKE_COMMAND 1 @@ -325,6 +332,8 @@ struct optee_msg_arg { #define OPTEE_MSG_CMD_CANCEL 3 #define OPTEE_MSG_CMD_REGISTER_SHM 4 #define OPTEE_MSG_CMD_UNREGISTER_SHM 5 +#define OPTEE_MSG_CMD_DO_BOTTOM_HALF 6 +#define OPTEE_MSG_CMD_STOP_ASYNC_NOTIF 7 #define OPTEE_MSG_FUNCID_CALL_WITH_ARG 0x0004
#endif /* _OPTEE_MSG_H */ diff --git a/drivers/tee/optee/optee_private.h b/drivers/tee/optee/optee_private.h index 68fd28f8c6e9..46f74ab07c7e 100644 --- a/drivers/tee/optee/optee_private.h +++ b/drivers/tee/optee/optee_private.h @@ -53,6 +53,7 @@ struct optee_call_queue {
struct optee_notif { u_int max_key; + struct tee_context *ctx; /* Serializes access to the elements below in this struct */ spinlock_t lock; struct list_head db; @@ -88,6 +89,7 @@ struct optee_smc { optee_invoke_fn *invoke_fn; void *memremaped_shm; u32 sec_caps; + unsigned int notif_irq; };
/** diff --git a/drivers/tee/optee/optee_smc.h b/drivers/tee/optee/optee_smc.h index 80eb763a8a80..d44a6ae994f8 100644 --- a/drivers/tee/optee/optee_smc.h +++ b/drivers/tee/optee/optee_smc.h @@ -107,6 +107,12 @@ struct optee_smc_call_get_os_revision_result { /* * Call with struct optee_msg_arg as argument * + * When calling this function normal world has a few responsibilities: + * 1. It must be able to handle eventual RPCs + * 2. Non-secure interrupts should not be masked + * 3. If asynchronous notifications has been negotiated successfully, then + * asynchronous notifications should be unmasked during this call. + * * Call register usage: * a0 SMC Function ID, OPTEE_SMC*CALL_WITH_ARG * a1 Upper 32 bits of a 64-bit physical pointer to a struct optee_msg_arg @@ -195,7 +201,8 @@ struct optee_smc_get_shm_config_result { * Normal return register usage: * a0 OPTEE_SMC_RETURN_OK * a1 bitfield of secure world capabilities OPTEE_SMC_SEC_CAP_* - * a2-7 Preserved + * a2 The maximum secure world notification number + * a3-7 Preserved * * Error return register usage: * a0 OPTEE_SMC_RETURN_ENOTAVAIL, can't use the capabilities from normal world @@ -218,6 +225,8 @@ struct optee_smc_get_shm_config_result { #define OPTEE_SMC_SEC_CAP_VIRTUALIZATION BIT(3) /* Secure world supports Shared Memory with a NULL reference */ #define OPTEE_SMC_SEC_CAP_MEMREF_NULL BIT(4) +/* Secure world supports asynchronous notification of normal world */ +#define OPTEE_SMC_SEC_CAP_ASYNC_NOTIF BIT(5)
#define OPTEE_SMC_FUNCID_EXCHANGE_CAPABILITIES 9 #define OPTEE_SMC_EXCHANGE_CAPABILITIES \ @@ -226,8 +235,8 @@ struct optee_smc_get_shm_config_result { struct optee_smc_exchange_capabilities_result { unsigned long status; unsigned long capabilities; + unsigned long max_notif_value; unsigned long reserved0; - unsigned long reserved1; };
/* @@ -319,6 +328,68 @@ struct optee_smc_disable_shm_cache_result { #define OPTEE_SMC_GET_THREAD_COUNT \ OPTEE_SMC_FAST_CALL_VAL(OPTEE_SMC_FUNCID_GET_THREAD_COUNT)
+/* + * Inform OP-TEE that normal world is able to receive asynchronous + * notifications. + * + * Call requests usage: + * a0 SMC Function ID, OPTEE_SMC_ENABLE_ASYNC_NOTIF + * a1-6 Not used + * a7 Hypervisor Client ID register + * + * Normal return register usage: + * a0 OPTEE_SMC_RETURN_OK + * a1-7 Preserved + * + * Not supported return register usage: + * a0 OPTEE_SMC_RETURN_ENOTAVAIL + * a1-7 Preserved + */ +#define OPTEE_SMC_FUNCID_ENABLE_ASYNC_NOTIF 16 +#define OPTEE_SMC_ENABLE_ASYNC_NOTIF \ + OPTEE_SMC_FAST_CALL_VAL(OPTEE_SMC_FUNCID_ENABLE_ASYNC_NOTIF) + +/* + * Retrieve a value of notifications pending since the last call of this + * function. + * + * OP-TEE keeps a record of all posted values. When an interrupt is + * received which indicates that there are posted values this function + * should be called until all pended values have been retrieved. When a + * value is retrieved, it's cleared from the record in secure world. + * + * Call requests usage: + * a0 SMC Function ID, OPTEE_SMC_GET_ASYNC_NOTIF_VALUE + * a1-6 Not used + * a7 Hypervisor Client ID register + * + * Normal return register usage: + * a0 OPTEE_SMC_RETURN_OK + * a1 value + * a2 Bit[0]: OPTEE_SMC_ASYNC_NOTIF_VALUE_VALID if the value in a1 is + * valid, else 0 if no values where pending + * a2 Bit[1]: OPTEE_SMC_ASYNC_NOTIF_VALUE_PENDING if another value is + * pending, else 0. + * Bit[31:2]: MBZ + * a3-7 Preserved + * + * Not supported return register usage: + * a0 OPTEE_SMC_RETURN_ENOTAVAIL + * a1-7 Preserved + */ +#define OPTEE_SMC_ASYNC_NOTIF_VALUE_VALID BIT(0) +#define OPTEE_SMC_ASYNC_NOTIF_VALUE_PENDING BIT(1) + +/* + * Notification that OP-TEE expects a yielding call to do some bottom half + * work in a driver. + */ +#define OPTEE_SMC_ASYNC_NOTIF_VALUE_DO_BOTTOM_HALF 0 + +#define OPTEE_SMC_FUNCID_GET_ASYNC_NOTIF_VALUE 17 +#define OPTEE_SMC_GET_ASYNC_NOTIF_VALUE \ + OPTEE_SMC_FAST_CALL_VAL(OPTEE_SMC_FUNCID_GET_ASYNC_NOTIF_VALUE) + /* * Resume from RPC (for example after processing a foreign interrupt) * diff --git a/drivers/tee/optee/smc_abi.c b/drivers/tee/optee/smc_abi.c index 00a7ff00a7c0..92759d70bfce 100644 --- a/drivers/tee/optee/smc_abi.c +++ b/drivers/tee/optee/smc_abi.c @@ -8,13 +8,16 @@
#include <linux/arm-smccc.h> #include <linux/errno.h> +#include <linux/interrupt.h> #include <linux/io.h> -#include <linux/sched.h> +#include <linux/irqdomain.h> #include <linux/mm.h> #include <linux/module.h> #include <linux/of.h> +#include <linux/of_irq.h> #include <linux/of_platform.h> #include <linux/platform_device.h> +#include <linux/sched.h> #include <linux/slab.h> #include <linux/string.h> #include <linux/tee_drv.h> @@ -34,7 +37,8 @@ * 2. Low level support functions to register shared memory in secure world * 3. Dynamic shared memory pool based on alloc_pages() * 4. Do a normal scheduled call into secure world - * 5. Driver initialization. + * 5. Asynchronous notification + * 6. Driver initialization. */
#define OPTEE_SHM_NUM_PRIV_PAGES CONFIG_OPTEE_SHM_NUM_PRIV_PAGES @@ -875,10 +879,137 @@ static int optee_smc_do_call_with_arg(struct tee_context *ctx, return rc; }
+static int simple_call_with_arg(struct tee_context *ctx, u32 cmd) +{ + struct optee_msg_arg *msg_arg; + struct tee_shm *shm; + + shm = optee_get_msg_arg(ctx, 0, &msg_arg); + if (IS_ERR(shm)) + return PTR_ERR(shm); + + msg_arg->cmd = cmd; + optee_smc_do_call_with_arg(ctx, shm); + + tee_shm_free(shm); + return 0; +} + +static int optee_smc_do_bottom_half(struct tee_context *ctx) +{ + return simple_call_with_arg(ctx, OPTEE_MSG_CMD_DO_BOTTOM_HALF); +} + +static int optee_smc_stop_async_notif(struct tee_context *ctx) +{ + return simple_call_with_arg(ctx, OPTEE_MSG_CMD_STOP_ASYNC_NOTIF); +} + /* - * 5. Driver initialization + * 5. Asynchronous notification + */ + +static u32 get_async_notif_value(optee_invoke_fn *invoke_fn, bool *value_valid, + bool *value_pending) +{ + struct arm_smccc_res res; + + invoke_fn(OPTEE_SMC_GET_ASYNC_NOTIF_VALUE, 0, 0, 0, 0, 0, 0, 0, &res); + + if (res.a0) + return 0; + *value_valid = (res.a2 & OPTEE_SMC_ASYNC_NOTIF_VALUE_VALID); + *value_pending = (res.a2 & OPTEE_SMC_ASYNC_NOTIF_VALUE_PENDING); + return res.a1; +} + +static irqreturn_t notif_irq_handler(int irq, void *dev_id) +{ + struct optee *optee = dev_id; + bool do_bottom_half = false; + bool value_valid; + bool value_pending; + u32 value; + + do { + value = get_async_notif_value(optee->smc.invoke_fn, + &value_valid, &value_pending); + if (!value_valid) + break; + + if (value == OPTEE_SMC_ASYNC_NOTIF_VALUE_DO_BOTTOM_HALF) + do_bottom_half = true; + else + optee_notif_send(optee, value); + } while (value_pending); + + if (do_bottom_half) + return IRQ_WAKE_THREAD; + return IRQ_HANDLED; +} + +static irqreturn_t notif_irq_thread_fn(int irq, void *dev_id) +{ + struct optee *optee = dev_id; + + optee_smc_do_bottom_half(optee->notif.ctx); + + return IRQ_HANDLED; +} + +static int optee_smc_notif_init_irq(struct optee *optee, u_int irq) +{ + struct tee_context *ctx; + int rc; + + ctx = teedev_open(optee->teedev); + if (IS_ERR(ctx)) + return PTR_ERR(ctx); + + optee->notif.ctx = ctx; + rc = request_threaded_irq(irq, notif_irq_handler, + notif_irq_thread_fn, + 0, "optee_notification", optee); + if (rc) + goto err_close_ctx; + + optee->smc.notif_irq = irq; + + return 0; + +err_close_ctx: + teedev_close_context(optee->notif.ctx); + optee->notif.ctx = NULL; + + return rc; +} + +static void optee_smc_notif_uninit_irq(struct optee *optee) +{ + if (optee->notif.ctx) { + optee_smc_stop_async_notif(optee->notif.ctx); + if (optee->smc.notif_irq) { + free_irq(optee->smc.notif_irq, optee); + irq_dispose_mapping(optee->smc.notif_irq); + } + + /* + * The thread normally working with optee->notif.ctx was + * stopped with free_irq() above. + * + * Note we're not using teedev_close_context() or + * tee_client_close_context() since we have already called + * tee_device_put() while initializing to avoid a circular + * reference counting. + */ + teedev_close_context(optee->notif.ctx); + } +} + +/* + * 6. Driver initialization * - * During driver inititialization is secure world probed to find out which + * During driver initialization is secure world probed to find out which * features it supports so the driver can be initialized with a matching * configuration. This involves for instance support for dynamic shared * memory instead of a static memory carvout. @@ -950,6 +1081,17 @@ static const struct optee_ops optee_ops = { .from_msg_param = optee_from_msg_param, };
+static int enable_async_notif(optee_invoke_fn *invoke_fn) +{ + struct arm_smccc_res res; + + invoke_fn(OPTEE_SMC_ENABLE_ASYNC_NOTIF, 0, 0, 0, 0, 0, 0, 0, &res); + + if (res.a0) + return -EINVAL; + return 0; +} + static bool optee_msg_api_uid_is_optee_api(optee_invoke_fn *invoke_fn) { struct arm_smccc_res res; @@ -999,7 +1141,7 @@ static bool optee_msg_api_revision_is_compatible(optee_invoke_fn *invoke_fn) }
static bool optee_msg_exchange_capabilities(optee_invoke_fn *invoke_fn, - u32 *sec_caps) + u32 *sec_caps, u32 *max_notif_value) { union { struct arm_smccc_res smccc; @@ -1022,6 +1164,11 @@ static bool optee_msg_exchange_capabilities(optee_invoke_fn *invoke_fn, return false;
*sec_caps = res.result.capabilities; + if (*sec_caps & OPTEE_SMC_SEC_CAP_ASYNC_NOTIF) + *max_notif_value = res.result.max_notif_value; + else + *max_notif_value = OPTEE_DEFAULT_MAX_NOTIF_VALUE; + return true; }
@@ -1186,6 +1333,8 @@ static int optee_smc_remove(struct platform_device *pdev) */ optee_disable_shm_cache(optee);
+ optee_smc_notif_uninit_irq(optee); + optee_remove_common(optee);
if (optee->smc.memremaped_shm) @@ -1215,6 +1364,7 @@ static int optee_probe(struct platform_device *pdev) struct optee *optee = NULL; void *memremaped_shm = NULL; struct tee_device *teedev; + u32 max_notif_value; u32 sec_caps; int rc;
@@ -1234,7 +1384,8 @@ static int optee_probe(struct platform_device *pdev) return -EINVAL; }
- if (!optee_msg_exchange_capabilities(invoke_fn, &sec_caps)) { + if (!optee_msg_exchange_capabilities(invoke_fn, &sec_caps, + &max_notif_value)) { pr_warn("capabilities mismatch\n"); return -EINVAL; } @@ -1257,7 +1408,7 @@ static int optee_probe(struct platform_device *pdev) optee = kzalloc(sizeof(*optee), GFP_KERNEL); if (!optee) { rc = -ENOMEM; - goto err; + goto err_free_pool; }
optee->ops = &optee_ops; @@ -1267,24 +1418,24 @@ static int optee_probe(struct platform_device *pdev) teedev = tee_device_alloc(&optee_clnt_desc, NULL, pool, optee); if (IS_ERR(teedev)) { rc = PTR_ERR(teedev); - goto err; + goto err_free_optee; } optee->teedev = teedev;
teedev = tee_device_alloc(&optee_supp_desc, NULL, pool, optee); if (IS_ERR(teedev)) { rc = PTR_ERR(teedev); - goto err; + goto err_unreg_teedev; } optee->supp_teedev = teedev;
rc = tee_device_register(optee->teedev); if (rc) - goto err; + goto err_unreg_supp_teedev;
rc = tee_device_register(optee->supp_teedev); if (rc) - goto err; + goto err_unreg_supp_teedev;
mutex_init(&optee->call_queue.mutex); INIT_LIST_HEAD(&optee->call_queue.waiters); @@ -1293,10 +1444,27 @@ static int optee_probe(struct platform_device *pdev) optee->pool = pool;
platform_set_drvdata(pdev, optee); - rc = optee_notif_init(optee, OPTEE_DEFAULT_MAX_NOTIF_VALUE); - if (rc) { - optee_remove(pdev); - return rc; + rc = optee_notif_init(optee, max_notif_value); + if (rc) + goto err_supp_uninit; + + if (sec_caps & OPTEE_SMC_SEC_CAP_ASYNC_NOTIF) { + unsigned int irq; + + rc = platform_get_irq(pdev, 0); + if (rc < 0) { + pr_err("platform_get_irq: ret %d\n", rc); + goto err_notif_uninit; + } + irq = rc; + + rc = optee_smc_notif_init_irq(optee, irq); + if (rc) { + irq_dispose_mapping(irq); + goto err_notif_uninit; + } + enable_async_notif(optee->smc.invoke_fn); + pr_info("Asynchronous notifications enabled\n"); }
/* @@ -1314,28 +1482,31 @@ static int optee_probe(struct platform_device *pdev) pr_info("dynamic shared memory is enabled\n");
rc = optee_enumerate_devices(PTA_CMD_GET_DEVICES); - if (rc) { - optee_smc_remove(pdev); - return rc; - } + if (rc) + goto err_disable_shm_cache;
pr_info("initialized driver\n"); return 0; -err: - if (optee) { - /* - * tee_device_unregister() is safe to call even if the - * devices hasn't been registered with - * tee_device_register() yet. - */ - tee_device_unregister(optee->supp_teedev); - tee_device_unregister(optee->teedev); - kfree(optee); - } - if (pool) - tee_shm_pool_free(pool); - if (memremaped_shm) - memunmap(memremaped_shm); + +err_disable_shm_cache: + optee_disable_shm_cache(optee); + optee_smc_notif_uninit_irq(optee); + optee_unregister_devices(); +err_notif_uninit: + optee_notif_uninit(optee); +err_supp_uninit: + optee_supp_uninit(&optee->supp); + mutex_destroy(&optee->call_queue.mutex); +err_unreg_supp_teedev: + tee_device_unregister(optee->supp_teedev); +err_unreg_teedev: + tee_device_unregister(optee->teedev); +err_free_optee: + kfree(optee); +err_free_pool: + tee_shm_pool_free(pool); + if (optee->smc.memremaped_shm) + memunmap(optee->smc.memremaped_shm); return rc; }
op-tee@lists.trustedfirmware.org
-
Jens Wiklander