tpm/tpm_crb: Access locality for only CRB_START method

For ARM64, the locality is handled by Trust Zone in FW. The layout does not have crb_regs_head. It is hitting the following line.
dev_warn(dev, FW_BUG "Bad ACPI memory layout");

Current code excludes CRB_FL_ACPI_START and when CRB_FL_CRB_SMC_START is added around the same time locality support is added, it should also be excluded. Change the if condition to be only for CRB_FL_CRB_START.

For goIdle and cmdReady where code was excluding CRB_FL_ACPI_START only (do nothing for ACPI start method), CRB_FL_CRB_SMC_START was also excluded as ARM64 SMC start method does not have TPM_CRB_CTRL_REQ.
Change the if condition to be only for CRB_FL_CRB_START in crb_go_idle() and crb_cmd_ready().

Signed-off-by Jiandi An <[email protected]>

---
v2
Changed if condition to CRB_FL_CRB_START for go idle and crb_cmd_ready per maintainer's comment.

 drivers/char/tpm/tpm_crb.c | 36 +++++++++++++++++-------------------
 1 file changed, 17 insertions(+), 19 deletions(-)

drivers/char/tpm/tpm_crb.c +6 -10

index 8f0a98d..7a6735d 100644
@@ -128,18 +128,16 @@ struct tpm2_crb_smc {
  * Anyhow, we do not wait here as a consequent CMD_READY request
  * will be handled correctly even if idle was not completed.
  *
- * The function does nothing for devices with ACPI-start method.
+ * The function does nothing for devices with ACPI-start method
+ * and SMC-start method.
  *
  * Return: 0 always
  */
 static int __maybe_unused crb_go_idle(struct device *dev, struct crb_priv *priv)
 {
-	if ((priv->flags & CRB_FL_ACPI_START) ||
-	    (priv->flags & CRB_FL_CRB_SMC_START))
-		return 0;
-
-	iowrite32(CRB_CTRL_REQ_GO_IDLE, &priv->regs_t->ctrl_req);
-	/* we don't really care when this settles */
+	if (priv->flags & CRB_FL_CRB_START)
+		iowrite32(CRB_CTRL_REQ_GO_IDLE, &priv->regs_t->ctrl_req);
+		/* we don't really care when this settles */
 
 	return 0;
 }

@@ -174,23 +172,23 @@ static bool crb_wait_for_reg_32(u32 __iomem *reg, u32 mask, u32 value,
  * The device should respond within TIMEOUT_C.
  *
  * The function does nothing for devices with ACPI-start method
+ * and SMC-start method.
  *
  * Return: 0 on success -ETIME on timeout;
  */
 static int __maybe_unused crb_cmd_ready(struct device *dev,
 					struct crb_priv *priv)
 {
-	if ((priv->flags & CRB_FL_ACPI_START) ||
-	    (priv->flags & CRB_FL_CRB_SMC_START))
-		return 0;

drivers/char/tpm/tpm_crb.c +9 -1

+		iowrite32(CRB_CTRL_REQ_CMD_READY, &priv->regs_t->ctrl_req);
+		if (!crb_wait_for_reg_32(&priv->regs_t->ctrl_req,
+					 CRB_CTRL_REQ_CMD_READY /* mask */,
+					 0, /* value */
+					 TPM2_TIMEOUT_C)) {
+			dev_warn(dev, "cmdReady timed out\n");
+			return -ETIME;
+		}
 	}
 
 	return 0;

@@ -458,7 +456,7 @@ static int crb_map_io(struct acpi_device *device, struct crb_priv *priv,
 	 * the control area, as one nice sane region except for some older
 	 * stuff that puts the control area outside the ACPI IO region.
 	 */
-	if (!(priv->flags & CRB_FL_ACPI_START)) {
+	if (priv->flags & CRB_FL_CRB_START) {
 		if (buf->control_address == io_res.start +
 		    sizeof(*priv->regs_h))
 			priv->regs_h = priv->iobase;

Signature · 3 lines

Jiandi An
Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc.
Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.