tpm: Fix cancellation of TPM commands (interrupt mode)

Support cancellation of TPM commands when driver is used in interrupt
mode.

Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Signed-off-by: Kent Yoder <key@linux.vnet.ibm.com>

3 files changed, 31 insertions, 12 deletions

diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c
index a244cd3e7dbc..0d2e82f95577 100644
--- a/drivers/char/tpm/tpm.c
+++ b/drivers/char/tpm/tpm.c
@@ -1102,12 +1102,28 @@ ssize_t tpm_store_cancel(struct device *dev, struct device_attribute *attr,
 }
 EXPORT_SYMBOL_GPL(tpm_store_cancel);
 
+static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask, bool check_cancel,
+                                   bool *canceled)
+{
+        u8 status = chip->vendor.status(chip);
+
+        *canceled = false;
+        if ((status & mask) == mask)
+                return true;
+        if (check_cancel && chip->vendor.req_canceled(chip, status)) {
+                *canceled = true;
+                return true;
+        }
+        return false;
+}
+
 int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
-                         wait_queue_head_t *queue)
+                      wait_queue_head_t *queue, bool check_cancel)
 {
         unsigned long stop;
         long rc;
         u8 status;
+        bool canceled = false;
 
         /* check current status */
         status = chip->vendor.status(chip);
@@ -1122,11 +1138,14 @@ again:
                 if ((long)timeout <= 0)
                         return -ETIME;
                 rc = wait_event_interruptible_timeout(*queue,
-                                                      ((chip->vendor.status(chip)
-                                                      & mask) == mask),
-                                                      timeout);
-                if (rc > 0)
+                        wait_for_tpm_stat_cond(chip, mask, check_cancel,
+                                               &canceled),
+                        timeout);
+                if (rc > 0) {
+                        if (canceled)
+                                return -ECANCELED;
                         return 0;
+                }
                 if (rc == -ERESTARTSYS && freezing(current)) {
                         clear_thread_flag(TIF_SIGPENDING);
                         goto again;
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 725cb9b657dd..81b52015f669 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -338,7 +338,7 @@ extern void tpm_remove_hardware(struct device *);
 extern int tpm_pm_suspend(struct device *);
 extern int tpm_pm_resume(struct device *);
 extern int wait_for_tpm_stat(struct tpm_chip *, u8, unsigned long,
-                             wait_queue_head_t *);
+                             wait_queue_head_t *, bool);
 
 #ifdef CONFIG_ACPI
 extern int tpm_add_ppi(struct kobject *);
diff --git a/drivers/char/tpm/tpm_tis.c b/drivers/char/tpm/tpm_tis.c
index e4e0c65df768..ae91c115c438 100644
--- a/drivers/char/tpm/tpm_tis.c
+++ b/drivers/char/tpm/tpm_tis.c
@@ -198,7 +198,7 @@ static int recv_data(struct tpm_chip *chip, u8 *buf, size_t count)
                wait_for_tpm_stat(chip,
                                  TPM_STS_DATA_AVAIL | TPM_STS_VALID,
                                  chip->vendor.timeout_c,
-                                 &chip->vendor.read_queue)
+                                 &chip->vendor.read_queue, true)
                == 0) {
                 burstcnt = get_burstcount(chip);
                 for (; burstcnt > 0 && size < count; burstcnt--)
@@ -241,7 +241,7 @@ static int tpm_tis_recv(struct tpm_chip *chip, u8 *buf, size_t count)
         }
 
         wait_for_tpm_stat(chip, TPM_STS_VALID, chip->vendor.timeout_c,
-                          &chip->vendor.int_queue);
+                          &chip->vendor.int_queue, false);
         status = tpm_tis_status(chip);
         if (status & TPM_STS_DATA_AVAIL) {      /* retry? */
                 dev_err(chip->dev, "Error left over data\n");
@@ -277,7 +277,7 @@ static int tpm_tis_send_data(struct tpm_chip *chip, u8 *buf, size_t len)
                 tpm_tis_ready(chip);
                 if (wait_for_tpm_stat
                     (chip, TPM_STS_COMMAND_READY, chip->vendor.timeout_b,
-                     &chip->vendor.int_queue) < 0) {
+                     &chip->vendor.int_queue, false) < 0) {
                         rc = -ETIME;
                         goto out_err;
                 }
@@ -292,7 +292,7 @@ static int tpm_tis_send_data(struct tpm_chip *chip, u8 *buf, size_t len)
                 }
 
                 wait_for_tpm_stat(chip, TPM_STS_VALID, chip->vendor.timeout_c,
-                                  &chip->vendor.int_queue);
+                                  &chip->vendor.int_queue, false);
                 status = tpm_tis_status(chip);
                 if (!itpm && (status & TPM_STS_DATA_EXPECT) == 0) {
                         rc = -EIO;
@@ -304,7 +304,7 @@ static int tpm_tis_send_data(struct tpm_chip *chip, u8 *buf, size_t len)
         iowrite8(buf[count],
                  chip->vendor.iobase + TPM_DATA_FIFO(chip->vendor.locality));
         wait_for_tpm_stat(chip, TPM_STS_VALID, chip->vendor.timeout_c,
-                          &chip->vendor.int_queue);
+                          &chip->vendor.int_queue, false);
         status = tpm_tis_status(chip);
         if ((status & TPM_STS_DATA_EXPECT) != 0) {
                 rc = -EIO;
@@ -342,7 +342,7 @@ static int tpm_tis_send(struct tpm_chip *chip, u8 *buf, size_t len)
                 if (wait_for_tpm_stat
                     (chip, TPM_STS_DATA_AVAIL | TPM_STS_VALID,
                      tpm_calc_ordinal_duration(chip, ordinal),
-                     &chip->vendor.read_queue) < 0) {
+                     &chip->vendor.read_queue, false) < 0) {
                         rc = -ETIME;
                         goto out_err;
                 }