On 08/22/2017 12:39 PM, Jarkko Sakkinen wrote:
On Thu, Aug 17, 2017 at 11:15:36PM -0500, Jiandi An wrote:
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.

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 if confition to white list instead of black list.

Signed-off-by: Jiandi An <anjia...@codeaurora.org>
---
 drivers/char/tpm/tpm_crb.c | 35 ++++++++++++++++-------------------
 1 file changed, 16 insertions(+), 19 deletions(-)

diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
index 8f0a98d..cbfdbdde 100644
--- a/drivers/char/tpm/tpm_crb.c
+++ b/drivers/char/tpm/tpm_crb.c
@@ -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
+ * or 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_ACPI_START | CRB_FL_CRB_SMC_START)) == 0)
+               iowrite32(CRB_CTRL_REQ_GO_IDLE, &priv->regs_t->ctrl_req);
+               /* we don't really care when this settles */

It's *exactly* the same condition expessed in different form.


I'm sorry perhaps I didn't fully understand the workaround specific to Intel PPT. In previous patch thread, you mentioned the following where
a platform could report to require start method 2 (ACPI start) which is
sm = ACPI_TPM2_START_METHOD, and actually requires start method 8, which
is sm = ACPI_TPM2_COMMAND_BUFFER_WITH_START_METHOD.

But you listed the following code logic which for either sm = 2 or
sm = 8, CRB_FL_ACPI_START flag is set.

if (sm == ACPI_TPM2_START_METHOD ||
    sm == ACPI_TPM2_COMMAND_BUFFER_WITH_START_METHOD)
        priv->flags |= CRB_FL_ACPI_START;

So I'm a little confused about the PPT workaround you mentioned

/* The reason for the extra quirk is that the PTT in 4th Gen Core CPUs
 * report only ACPI start but in practice seems to require both
 * ACPI start and CRB start.
 */
if (sm == ACPI_TPM2_COMMAND_BUFFER || sm == ACPI_TPM2_MEMORY_MAPPED ||
    !strcmp(acpi_device_hid(device), "MSFT0101"))
        priv->flags |= CRB_FL_CRB_START;

I took it as some platform sm = 2 or sm = 8 which CRB_FL_ACPI_START
flag is set, additionally, if HID = MSFT0101, CRB_FL_CRB_START flag
is set.

So I took it as the PPT workaround you mentioned is an instance where
both CRB_FL_ACPI_START and CRB_FL_CRB_START are set.

The original code logic for crb_go_idle() and crb_cmd_ready() only
exclude CRB_FL_ACPI_START, saying crb_go_idle() and crb_cmd_ready()
do nothing if CRB_FL_ACPI_START is set.

static int __maybe_unused crb_go_idle(struct device *dev,
                                      struct crb_priv *priv)
{
     if (priv->flags & CRB_FL_ACPI_START)
         return 0;

So even in the case when both CRB_FL_ACPI_START and CRB_FL_CRB_START
are set, crb_go_idle() and crb_cmd_ready() will not do anything because
CRB_FL_ACPI_START is set.

And when SMC start method was enabled for ARM64, I further excluded
CRB_FL_CRB_SMC_START

static int __maybe_unused crb_go_idle(struct device *dev,
                                      struct crb_priv *priv)
{
     if ((priv->flags & CRB_FL_ACPI_START) ||
         (prive->flags & CRB_FL_CRB_SMC_START))
         return 0;

And Jason's comment was telling me to have these list the cases where
crb_go_idle() and crb_cmd_ready() are known to be required.  Less
brittle that way.  And he gave example...

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


The following is your comment and Jason's comment in the other patch
thread discussion here
https://sourceforge.net/p/tpmdd/mailman/message/35984747/

*****************************
What about platforms with firmware bug that they report only requiring
ACPI start but actually also require CRB start.

if (sm == ACPI_TPM2_START_METHOD ||
    sm == ACPI_TPM2_COMMAND_BUFFER_WITH_START_METHOD)
        priv->flags |= CRB_FL_ACPI_START;

I've encountered a platform that reports to require start method 2 (ACPI
start) while it actually requires start method 8.

That's why we have this nasty workaround:

/* The reason for the extra quirk is that the PTT in 4th Gen Core CPUs
 * report only ACPI start but in practice seems to require both
 * ACPI start and CRB start.
 */
if (sm == ACPI_TPM2_COMMAND_BUFFER || sm == ACPI_TPM2_MEMORY_MAPPED ||
    !strcmp(acpi_device_hid(device), "MSFT0101"))
        priv->flags |= CRB_FL_CRB_START;

Also, since start method 8 exist in the spec, it is a legit config.

/Jarkko


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

Jason
*****************************

The intent of this patch is to additionally exclude CRB_FL_CRB_SMC_START
from crb_go_idle(), crb_cmd_ready(), and the check for "Bad ACPI memory
layout" in crb_map_io(), on top of current conditions.

The original code just has as long as CRB_FL_ACPI_START is not set,
don't do crb_go_idle(), crb_cmd_ready() and the additional check for
"Bad ACPI memory layout" in crb_map_io().

Could you share some insight on what exact conditions are for crb_go_idle(), crb_cmd_ready(), and the check "BAD ACPI memory layout" in crb_map_io()?

Is it as long as !CRB_FL_ACPI_START? (before SMC was added, that just
means CRB_FL_CRB_START is set).
So with the PTT workaround condition, are you suggesting the following
conditions are when crb_go_idle(), crb_cmd_ready(), and check for "Bad ACPI memory layout" in crb_map_io() should run?

1. CRB_FL_CRB_START is set.
2. CRB_FL_CRB_START and CRB_FL_ACPI_START are set.

Thanks.
- Jiandi



        return 0;
 }
@@ -174,23 +172,22 @@ 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
+ * or 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;
-
-       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;
+       if ((priv->flags & (CRB_FL_ACPI_START | CRB_FL_CRB_SMC_START)) == 0) {
+               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 +455,7 @@ 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_ACPI_START | CRB_FL_CRB_SMC_START)) == 0) {
                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.


NAK

/Jarkko


--
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.

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