diff mbox series

[v6,2/4] crypto: ccp: Return doorbell status code as an argument

Message ID 20230322210227.464-3-mario.limonciello@amd.com
State New
Headers
Series Use CCP driver to handle PSP I2C arbitration |

Commit Message

Mario Limonciello March 22, 2023, 9:02 p.m. UTC 
  If the doorbell failed to ring we return -EIO, but the caller can't
determine why it failed.  Pass the reason for the failure in an
argument for caller to investigate.

Suggested-by: Mark Hasemeyer <markhas@chromium.org>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
v5->v6:
 * New patch
---
 drivers/crypto/ccp/platform-access.c | 4 +++-
 include/linux/psp-platform-access.h  | 4 ++--
 2 files changed, 5 insertions(+), 3 deletions(-)

Comments

Mark Hasemeyer March 27, 2023, 4:26 p.m. UTC | #1 
> -int psp_ring_platform_doorbell(int msg)
> +int psp_ring_platform_doorbell(int msg, u32 *result)
>  {
>         struct psp_device *psp = psp_get_master_device();
>         struct psp_platform_access_device *pa_dev;
> @@ -184,6 +184,8 @@ int psp_ring_platform_doorbell(int msg)
>
>         val = FIELD_GET(PSP_CMDRESP_STS, ioread32(cmd));
>         if (val) {
> +               if (result)
> +                       *result = val;
>                 ret = -EIO;
>                 goto unlock;
>         }
The bitfields in the new mailbox architecture have changed, as it is
now a dedicated mailbox for I2C arbitration. The 8 lsbs are used for
command and response status, and bit 31 is the ready bit.
Accounting for these changes, I was able to get the TPM contention
test to pass locally. I also removed calls to "check_doorbell" and
"check_recovery" as those steps weren't described in the design doc.
diff mbox series

Patch

diff --git a/drivers/crypto/ccp/platform-access.c b/drivers/crypto/ccp/platform-access.c
index 3e97ce60270d..9f3d469bbe76 100644
--- a/drivers/crypto/ccp/platform-access.c
+++ b/drivers/crypto/ccp/platform-access.c
@@ -140,7 +140,7 @@  int psp_send_platform_access_msg(enum psp_platform_access_msg msg,
 }
 EXPORT_SYMBOL_GPL(psp_send_platform_access_msg);
 
-int psp_ring_platform_doorbell(int msg)
+int psp_ring_platform_doorbell(int msg, u32 *result)
 {
 	struct psp_device *psp = psp_get_master_device();
 	struct psp_platform_access_device *pa_dev;
@@ -184,6 +184,8 @@  int psp_ring_platform_doorbell(int msg)
 
 	val = FIELD_GET(PSP_CMDRESP_STS, ioread32(cmd));
 	if (val) {
+		if (result)
+			*result = val;
 		ret = -EIO;
 		goto unlock;
 	}
diff --git a/include/linux/psp-platform-access.h b/include/linux/psp-platform-access.h
index 89df4549fada..1b661341d8f3 100644
--- a/include/linux/psp-platform-access.h
+++ b/include/linux/psp-platform-access.h
@@ -45,9 +45,9 @@  int psp_send_platform_access_msg(enum psp_platform_access_msg, struct psp_reques
  *  -%EBUSY:     mailbox in recovery or in use
  *  -%ENODEV:    driver not bound with PSP device
  *  -%ETIMEDOUT: request timed out
- *  -%EIO:       unknown error (see kernel log)
+ *  -%EIO:       error will be stored in result argument
  */
-int psp_ring_platform_doorbell(int msg);
+int psp_ring_platform_doorbell(int msg, u32 *result);
 
 /**
  * psp_check_platform_access_status() - Checks whether platform features is ready