Messages in this thread Patch in this message | | | From | Tim Gardner <> | Subject | [PATCH 3/3] TPM: data_pending is no longer atomic | Date | Tue, 6 Dec 2011 11:29:22 -0700 |
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Now that data_pending is fully protected by a mutex, it no longer needs to be atomic.
Reported-by: Seth Forshee <seth.forshee@canonical.com> Cc: Debora Velarde <debora@linux.vnet.ibm.com> Cc: Rajiv Andrade <srajiv@linux.vnet.ibm.com> Cc: Marcel Selhorst <m.selhorst@sirrix.com> Cc: tpmdd-devel@lists.sourceforge.net Signed-off-by: Tim Gardner <tim.gardner@canonical.com> --- drivers/char/tpm/tpm.c | 16 ++++++++-------- drivers/char/tpm/tpm.h | 2 +- 2 files changed, 9 insertions(+), 9 deletions(-)
diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c index 70bf9e5..6ac164f 100644 --- a/drivers/char/tpm/tpm.c +++ b/drivers/char/tpm/tpm.c @@ -342,7 +342,7 @@ static void timeout_work(struct work_struct *work) struct tpm_chip *chip = container_of(work, struct tpm_chip, work); mutex_lock(&chip->buffer_mutex); - atomic_set(&chip->data_pending, 0); + chip->data_pending = 0; memset(chip->data_buffer, 0, TPM_BUFSIZE); mutex_unlock(&chip->buffer_mutex); } @@ -1043,7 +1043,7 @@ int tpm_open(struct inode *inode, struct file *file) return -ENOMEM; } - atomic_set(&chip->data_pending, 0); + chip->data_pending = 0; file->private_data = chip; return 0; @@ -1060,7 +1060,7 @@ int tpm_release(struct inode *inode, struct file *file) del_singleshot_timer_sync(&chip->user_read_timer); flush_work_sync(&chip->work); file->private_data = NULL; - atomic_set(&chip->data_pending, 0); + chip->data_pending = 0; kfree(chip->data_buffer); clear_bit(0, &chip->is_open); put_device(chip->dev); @@ -1078,7 +1078,7 @@ ssize_t tpm_write(struct file *file, const char __user *buf, /* cannot perform a write until the read has cleared either via tpm_read or a user_read_timer timeout */ - while (atomic_read(&chip->data_pending) != 0) { + while (chip->data_pending != 0) { mutex_unlock(&chip->buffer_mutex); msleep(TPM_TIMEOUT); mutex_lock(&chip->buffer_mutex); @@ -1096,7 +1096,7 @@ ssize_t tpm_write(struct file *file, const char __user *buf, /* atomic tpm command send and result receive */ out_size = tpm_transmit(chip, chip->data_buffer, TPM_BUFSIZE); - atomic_set(&chip->data_pending, out_size); + chip->data_pending = out_size; mutex_unlock(&chip->buffer_mutex); /* Set a timeout by which the reader must come claim the result */ @@ -1116,18 +1116,18 @@ ssize_t tpm_read(struct file *file, char __user *buf, del_singleshot_timer_sync(&chip->user_read_timer); flush_work_sync(&chip->work); mutex_lock(&chip->buffer_mutex); - ret_size = atomic_xchg(&chip->data_pending, 0); + ret_size = chip->data_pending; if (ret_size > 0) { /* relay data */ - ssize_t orig_ret_size = ret_size; if (size < ret_size) ret_size = size; rc = copy_to_user(buf, chip->data_buffer, ret_size); - memset(chip->data_buffer, 0, orig_ret_size); + memset(chip->data_buffer, 0, chip->data_pending); if (rc) ret_size = -EFAULT; } + chip->data_pending = 0; mutex_unlock(&chip->buffer_mutex); return ret_size; } diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h index 9c4163c..6ee8064 100644 --- a/drivers/char/tpm/tpm.h +++ b/drivers/char/tpm/tpm.h @@ -103,7 +103,7 @@ struct tpm_chip { /* Data passed to and from the tpm via the read/write calls */ u8 *data_buffer; - atomic_t data_pending; + size_t data_pending; struct mutex buffer_mutex; struct timer_list user_read_timer; /* user needs to claim result */ -- 1.7.0.4
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