diff options
Diffstat (limited to 'drivers/char/tpm/tpm_crb_ffa.c')
-rw-r--r-- | drivers/char/tpm/tpm_crb_ffa.c | 94 |
1 files changed, 66 insertions, 28 deletions
diff --git a/drivers/char/tpm/tpm_crb_ffa.c b/drivers/char/tpm/tpm_crb_ffa.c index 4ead61f01299..755b77b32ea4 100644 --- a/drivers/char/tpm/tpm_crb_ffa.c +++ b/drivers/char/tpm/tpm_crb_ffa.c @@ -10,8 +10,16 @@ #define pr_fmt(fmt) "CRB_FFA: " fmt #include <linux/arm_ffa.h> +#include <linux/delay.h> +#include <linux/moduleparam.h> #include "tpm_crb_ffa.h" +static unsigned int busy_timeout_ms = 2000; + +module_param(busy_timeout_ms, uint, 0644); +MODULE_PARM_DESC(busy_timeout_ms, + "Maximum time in ms to retry before giving up on busy"); + /* TPM service function status codes */ #define CRB_FFA_OK 0x05000001 #define CRB_FFA_OK_RESULTS_RETURNED 0x05000002 @@ -115,6 +123,7 @@ struct tpm_crb_ffa { }; static struct tpm_crb_ffa *tpm_crb_ffa; +static struct ffa_driver tpm_crb_ffa_driver; static int tpm_crb_ffa_to_linux_errno(int errno) { @@ -168,50 +177,51 @@ static int tpm_crb_ffa_to_linux_errno(int errno) */ int tpm_crb_ffa_init(void) { + int ret = 0; + + if (!IS_MODULE(CONFIG_TCG_ARM_CRB_FFA)) { + ret = ffa_register(&tpm_crb_ffa_driver); + if (ret) { + tpm_crb_ffa = ERR_PTR(-ENODEV); + return ret; + } + } + if (!tpm_crb_ffa) - return -ENOENT; + ret = -ENOENT; if (IS_ERR_VALUE(tpm_crb_ffa)) - return -ENODEV; + ret = -ENODEV; - return 0; + return ret; } EXPORT_SYMBOL_GPL(tpm_crb_ffa_init); -static int __tpm_crb_ffa_send_recieve(unsigned long func_id, - unsigned long a0, - unsigned long a1, - unsigned long a2) +static int __tpm_crb_ffa_try_send_receive(unsigned long func_id, + unsigned long a0, unsigned long a1, + unsigned long a2) { const struct ffa_msg_ops *msg_ops; int ret; - if (!tpm_crb_ffa) - return -ENOENT; - msg_ops = tpm_crb_ffa->ffa_dev->ops->msg_ops; if (ffa_partition_supports_direct_req2_recv(tpm_crb_ffa->ffa_dev)) { - memset(&tpm_crb_ffa->direct_msg_data2, 0x00, - sizeof(struct ffa_send_direct_data2)); - - tpm_crb_ffa->direct_msg_data2.data[0] = func_id; - tpm_crb_ffa->direct_msg_data2.data[1] = a0; - tpm_crb_ffa->direct_msg_data2.data[2] = a1; - tpm_crb_ffa->direct_msg_data2.data[3] = a2; + tpm_crb_ffa->direct_msg_data2 = (struct ffa_send_direct_data2){ + .data = { func_id, a0, a1, a2 }, + }; ret = msg_ops->sync_send_receive2(tpm_crb_ffa->ffa_dev, &tpm_crb_ffa->direct_msg_data2); if (!ret) ret = tpm_crb_ffa_to_linux_errno(tpm_crb_ffa->direct_msg_data2.data[0]); } else { - memset(&tpm_crb_ffa->direct_msg_data, 0x00, - sizeof(struct ffa_send_direct_data)); - - tpm_crb_ffa->direct_msg_data.data1 = func_id; - tpm_crb_ffa->direct_msg_data.data2 = a0; - tpm_crb_ffa->direct_msg_data.data3 = a1; - tpm_crb_ffa->direct_msg_data.data4 = a2; + tpm_crb_ffa->direct_msg_data = (struct ffa_send_direct_data){ + .data1 = func_id, + .data2 = a0, + .data3 = a1, + .data4 = a2, + }; ret = msg_ops->sync_send_receive(tpm_crb_ffa->ffa_dev, &tpm_crb_ffa->direct_msg_data); @@ -219,6 +229,33 @@ static int __tpm_crb_ffa_send_recieve(unsigned long func_id, ret = tpm_crb_ffa_to_linux_errno(tpm_crb_ffa->direct_msg_data.data1); } + return ret; +} + +static int __tpm_crb_ffa_send_receive(unsigned long func_id, unsigned long a0, + unsigned long a1, unsigned long a2) +{ + ktime_t start, stop; + int ret; + + if (!tpm_crb_ffa) + return -ENOENT; + + start = ktime_get(); + stop = ktime_add(start, ms_to_ktime(busy_timeout_ms)); + + for (;;) { + ret = __tpm_crb_ffa_try_send_receive(func_id, a0, a1, a2); + if (ret != -EBUSY) + break; + + usleep_range(50, 100); + if (ktime_after(ktime_get(), stop)) { + dev_warn(&tpm_crb_ffa->ffa_dev->dev, + "Busy retry timed out\n"); + break; + } + } return ret; } @@ -236,7 +273,7 @@ static int __tpm_crb_ffa_send_recieve(unsigned long func_id, * * Return: 0 on success, negative error code on failure. */ -int tpm_crb_ffa_get_interface_version(u16 *major, u16 *minor) +static int tpm_crb_ffa_get_interface_version(u16 *major, u16 *minor) { int rc; @@ -251,7 +288,7 @@ int tpm_crb_ffa_get_interface_version(u16 *major, u16 *minor) guard(mutex)(&tpm_crb_ffa->msg_data_lock); - rc = __tpm_crb_ffa_send_recieve(CRB_FFA_GET_INTERFACE_VERSION, 0x00, 0x00, 0x00); + rc = __tpm_crb_ffa_send_receive(CRB_FFA_GET_INTERFACE_VERSION, 0x00, 0x00, 0x00); if (!rc) { if (ffa_partition_supports_direct_req2_recv(tpm_crb_ffa->ffa_dev)) { *major = CRB_FFA_MAJOR_VERSION(tpm_crb_ffa->direct_msg_data2.data[1]); @@ -264,7 +301,6 @@ int tpm_crb_ffa_get_interface_version(u16 *major, u16 *minor) return rc; } -EXPORT_SYMBOL_GPL(tpm_crb_ffa_get_interface_version); /** * tpm_crb_ffa_start() - signals the TPM that a field has changed in the CRB @@ -289,7 +325,7 @@ int tpm_crb_ffa_start(int request_type, int locality) guard(mutex)(&tpm_crb_ffa->msg_data_lock); - return __tpm_crb_ffa_send_recieve(CRB_FFA_START, request_type, locality, 0x00); + return __tpm_crb_ffa_send_receive(CRB_FFA_START, request_type, locality, 0x00); } EXPORT_SYMBOL_GPL(tpm_crb_ffa_start); @@ -369,7 +405,9 @@ static struct ffa_driver tpm_crb_ffa_driver = { .id_table = tpm_crb_ffa_device_id, }; +#ifdef MODULE module_ffa_driver(tpm_crb_ffa_driver); +#endif MODULE_AUTHOR("Arm"); MODULE_DESCRIPTION("TPM CRB FFA driver"); |