2017-08-07 02:54:22

by Jiandi An

Subject: [PATCH] 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]>
---
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.

2017-08-08 22:36:55

by Jason Gunthorpe

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

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