[PATCH] tpm/tpm_crb: Access locality for only CRB_START method

[PATCH] tpm/tpm_crb: Access locality for only CRB_START method

[Jiandi An]

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 <anjiandi@codeaurora.org>
---
 drivers/char/tpm/tpm_crb.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
index 8f0a98d..d583c50 100644
--- a/drivers/char/tpm/tpm_crb.c
+++ b/drivers/char/tpm/tpm_crb.c
@@ -128,14 +128,14 @@ 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))
+	if (!(priv->flags & CRB_FL_CRB_START))
 		return 0;
 
 	iowrite32(CRB_CTRL_REQ_GO_IDLE, &priv->regs_t->ctrl_req);
@@ -174,14 +174,14 @@ 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))
+	if (!(priv->flags & CRB_FL_CRB_START))
 		return 0;
 
 	iowrite32(CRB_CTRL_REQ_CMD_READY, &priv->regs_t->ctrl_req);
@@ -458,7 +458,7 @@ 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;
-- 
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.

Re: [PATCH] tpm/tpm_crb: Access locality for only CRB_START method

[Jason Gunthorpe]

On Sun, Aug 06, 2017 at 09:54:15PM -0500, Jiandi An wrote:

>  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))
> +	if (!(priv->flags & CRB_FL_CRB_START))

I think it would be better to have these list the cases where go_idle
is known to be required. Less brittle that way..

  if ((priv->flags & (CRB_FL_ACPI_START | CRB_FL_CRB_START)) == 0)
       return 0

> -	if (!(priv->flags & CRB_FL_ACPI_START)) {
> +	if (priv->flags & CRB_FL_CRB_START) {

Eg like this now makes more sense, assumming CRB_START is the right
test :)

Jason