[PATCH v1 0/2] ArmPkg/ArmScmiDxe: Fix a bug uncovered with the new SCP firmware

[PATCH v1 0/2] ArmPkg/ArmScmiDxe: Fix a bug uncovered with the new SCP firmware

[Girish Pathak]

This series fixes a bug in the ArmScmiDxe which was revealed while
testing with the new SCP firmware. 

The changes can be seen at https://github.com/girishpathak/edk2/tree/281_scmi_fix_v1 

Girish Pathak (2):
  ArmPkg/ArmScmiDxe: Fix ASSERT error in SCMI DXE
  ArmPkg/ArmScmiDxe: Dynamically allocate buffer for protocol ids

 ArmPkg/Drivers/ArmScmiDxe/Scmi.c    |  5 --
 ArmPkg/Drivers/ArmScmiDxe/ScmiDxe.c | 62 ++++++++++++--------
 ArmPkg/Drivers/ArmScmiDxe/ScmiDxe.h |  9 +--
 3 files changed, 43 insertions(+), 33 deletions(-)

-- 
'Guid(CE165669-3EF3-493F-B85D-6190EE5B9759)'

[PATCH v1 1/2] ArmPkg/ArmScmiDxe: Fix ASSERT error in SCMI DXE

[Girish Pathak]

This change fixes a bug in the SCMI DXE which is observed with the
upcoming release of the SCP firmware.

The PROTOCOL_ID_MASK (0xF) which is used to generate an index in
the ProtocolInitFxns is wrong because protocol ids can be
anywhere in 0x10 - 15 or 0x80 - FF range. This mask generates
the same index for two different protocols e.g. for protocol ids
0x10 and 0x90, which causes duplicate initialization of a protocol
resulting in a failure.

This change removes the use of PROTOCOL_ID_MASK and instead
uses a list of protocol ids and their initialization functions
to identify a supported protocol and initialize it.

Change-Id: Ib004294d2bec853045ed6e811d123832fba555cd
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Girish Pathak <girish.pathak@arm.com>
---
 ArmPkg/Drivers/ArmScmiDxe/ScmiDxe.c | 35 ++++++++++----------
 ArmPkg/Drivers/ArmScmiDxe/ScmiDxe.h |  8 +++--
 2 files changed, 22 insertions(+), 21 deletions(-)

diff --git a/ArmPkg/Drivers/ArmScmiDxe/ScmiDxe.c b/ArmPkg/Drivers/ArmScmiDxe/ScmiDxe.c
index 2920c6f6f33c5bb8ac00c903a0b199ba5f06f4de..cc68cbc922fcc06bff8f7e0aa8b6bf64a9932874 100644
--- a/ArmPkg/Drivers/ArmScmiDxe/ScmiDxe.c
+++ b/ArmPkg/Drivers/ArmScmiDxe/ScmiDxe.c
@@ -29,13 +29,10 @@
 #include "ScmiDxe.h"
 #include "ScmiPrivate.h"
 
-STATIC CONST SCMI_PROTOCOL_INIT_TABLE ProtocolInitFxns[MAX_PROTOCOLS] = {
-  { ScmiBaseProtocolInit },
-  { NULL },
-  { NULL },
-  { ScmiPerformanceProtocolInit },
-  { ScmiClockProtocolInit },
-  { NULL }
+STATIC CONST SCMI_PROTOCOL_ENTRY Protocols[] = {
+  { SCMI_PROTOCOL_ID_BASE, ScmiBaseProtocolInit },
+  { SCMI_PROTOCOL_ID_PERFORMANCE, ScmiPerformanceProtocolInit },
+  { SCMI_PROTOCOL_ID_CLOCK, ScmiClockProtocolInit }
 };
 
 /** ARM SCMI driver entry point function.
@@ -65,14 +62,14 @@ ArmScmiDxeEntryPoint (
   UINT32              Version;
   UINT32              Index;
   UINT32              NumProtocols;
-  UINT32              ProtocolNo;
+  UINT32              ProtocolIndex = 0;
   UINT8               SupportedList[MAX_PROTOCOLS];
   UINT32              SupportedListSize = sizeof (SupportedList);
 
-  ProtocolNo = SCMI_PROTOCOL_ID_BASE & PROTOCOL_ID_MASK;
-
   // Every SCMI implementation must implement the base protocol.
-  Status = ProtocolInitFxns[ProtocolNo].Init (&ImageHandle);
+  ASSERT (Protocols[ProtocolIndex].Id == SCMI_PROTOCOL_ID_BASE);
+
+  Status = Protocols[ProtocolIndex].InitFxn (&ImageHandle);
   if (EFI_ERROR (Status)) {
     ASSERT (FALSE);
     return Status;
@@ -123,13 +120,15 @@ ArmScmiDxeEntryPoint (
   }
 
   // Install supported protocol on ImageHandle.
-  for (Index = 0; Index < NumProtocols; Index++) {
-    ProtocolNo = SupportedList[Index] & PROTOCOL_ID_MASK;
-    if (ProtocolInitFxns[ProtocolNo].Init != NULL) {
-      Status = ProtocolInitFxns[ProtocolNo].Init (&ImageHandle);
-      if (EFI_ERROR (Status)) {
-        ASSERT (FALSE);
-        return Status;
+  while (++ProtocolIndex < ARRAY_SIZE (Protocols)) {
+    for (Index = 0; Index < NumProtocols; Index++) {
+      if (Protocols[ProtocolIndex].Id == SupportedList[Index]) {
+        Status = Protocols[ProtocolIndex].InitFxn (&ImageHandle);
+        if (EFI_ERROR (Status)) {
+          ASSERT (FALSE);
+          return Status;
+        }
+        break;
       }
     }
   }
diff --git a/ArmPkg/Drivers/ArmScmiDxe/ScmiDxe.h b/ArmPkg/Drivers/ArmScmiDxe/ScmiDxe.h
index 29cdde173659c701116b021a3c437a92b473e4e5..5815e1e78074067760b6f618e248526ee25e59c8 100644
--- a/ArmPkg/Drivers/ArmScmiDxe/ScmiDxe.h
+++ b/ArmPkg/Drivers/ArmScmiDxe/ScmiDxe.h
@@ -17,8 +17,9 @@
 #ifndef SCMI_DXE_H_
 #define SCMI_DXE_H_
 
+#include "ScmiPrivate.h"
+
 #define MAX_PROTOCOLS        6
-#define PROTOCOL_ID_MASK     0xF
 #define MAX_VENDOR_LEN       SCMI_MAX_STR_LEN
 
 /** Pointer to protocol initialization function.
@@ -35,7 +36,8 @@ EFI_STATUS
   );
 
 typedef struct {
-  SCMI_PROTOCOL_INIT_FXN Init;
-} SCMI_PROTOCOL_INIT_TABLE;
+  SCMI_PROTOCOL_ID Id;            // Protocol Id.
+  SCMI_PROTOCOL_INIT_FXN InitFxn; // Protocol init function.
+} SCMI_PROTOCOL_ENTRY;
 
 #endif /* SCMI_DXE_H_ */
-- 
'Guid(CE165669-3EF3-493F-B85D-6190EE5B9759)'

[PATCH v1 2/2] ArmPkg/ArmScmiDxe: Dynamically allocate buffer for protocol ids

[Girish Pathak]

Dynamically allocate the buffer to receive the SCMI protocol list.
This makes MAX_PROTOCOLS redundant, so it is removed.
It also fixes one minor code alignment issue and removes an unused
macro PROTOCOL_MASK.

Change-Id: Idc5880d4fb7b5c674f5fb7dce1198a7cad0303a7
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Girish Pathak <girish.pathak@arm.com>
---
 ArmPkg/Drivers/ArmScmiDxe/Scmi.c    |  5 ----
 ArmPkg/Drivers/ArmScmiDxe/ScmiDxe.c | 27 +++++++++++++++-----
 ArmPkg/Drivers/ArmScmiDxe/ScmiDxe.h |  1 -
 3 files changed, 21 insertions(+), 12 deletions(-)

diff --git a/ArmPkg/Drivers/ArmScmiDxe/Scmi.c b/ArmPkg/Drivers/ArmScmiDxe/Scmi.c
index 1e279f69cf615428dbb6477b8ac7de3258628df3..d247d3a932fe9f197460a95e9afa88681742e4b4 100644
--- a/ArmPkg/Drivers/ArmScmiDxe/Scmi.c
+++ b/ArmPkg/Drivers/ArmScmiDxe/Scmi.c
@@ -22,11 +22,6 @@
 
 #include "ScmiPrivate.h"
 
-// SCMI Specification 1.0
-#define  MAX_PROTOCOLS       6
-
-#define  PROTOCOL_MASK     0xF
-
 // Arbitrary timeout value 20ms.
 #define  RESPONSE_TIMEOUT  20000
 
diff --git a/ArmPkg/Drivers/ArmScmiDxe/ScmiDxe.c b/ArmPkg/Drivers/ArmScmiDxe/ScmiDxe.c
index cc68cbc922fcc06bff8f7e0aa8b6bf64a9932874..e7b9feca5e1b565fc031385bfe2f2dc0ca53aab0 100644
--- a/ArmPkg/Drivers/ArmScmiDxe/ScmiDxe.c
+++ b/ArmPkg/Drivers/ArmScmiDxe/ScmiDxe.c
@@ -63,8 +63,8 @@ ArmScmiDxeEntryPoint (
   UINT32              Index;
   UINT32              NumProtocols;
   UINT32              ProtocolIndex = 0;
-  UINT8               SupportedList[MAX_PROTOCOLS];
-  UINT32              SupportedListSize = sizeof (SupportedList);
+  UINT8               *SupportedList;
+  UINT32              SupportedListSize;
 
   // Every SCMI implementation must implement the base protocol.
   ASSERT (Protocols[ProtocolIndex].Id == SCMI_PROTOCOL_ID_BASE);
@@ -108,13 +108,26 @@ ArmScmiDxeEntryPoint (
 
   ASSERT (NumProtocols != 0);
 
+  SupportedListSize = (NumProtocols * sizeof (*SupportedList));
+
+  Status = gBS->AllocatePool (
+                  EfiBootServicesData,
+                  SupportedListSize,
+                  (VOID**)&SupportedList
+                  );
+  if (EFI_ERROR (Status)) {
+    ASSERT (FALSE);
+    return Status;
+  }
+
   // Get the list of protocols supported by SCP firmware on the platform.
   Status = BaseProtocol->DiscoverListProtocols (
-             BaseProtocol,
-             &SupportedListSize,
-             SupportedList
-             );
+                           BaseProtocol,
+                           &SupportedListSize,
+                           SupportedList
+                           );
   if (EFI_ERROR (Status)) {
+    gBS->FreePool (SupportedList);
     ASSERT (FALSE);
     return Status;
   }
@@ -133,5 +146,7 @@ ArmScmiDxeEntryPoint (
     }
   }
 
+  gBS->FreePool (SupportedList);
+
   return EFI_SUCCESS;
 }
diff --git a/ArmPkg/Drivers/ArmScmiDxe/ScmiDxe.h b/ArmPkg/Drivers/ArmScmiDxe/ScmiDxe.h
index 5815e1e78074067760b6f618e248526ee25e59c8..b50a52a01d47efbbccec8c97bf44041c47ff8b38 100644
--- a/ArmPkg/Drivers/ArmScmiDxe/ScmiDxe.h
+++ b/ArmPkg/Drivers/ArmScmiDxe/ScmiDxe.h
@@ -19,7 +19,6 @@
 
 #include "ScmiPrivate.h"
 
-#define MAX_PROTOCOLS        6
 #define MAX_VENDOR_LEN       SCMI_MAX_STR_LEN
 
 /** Pointer to protocol initialization function.
-- 
'Guid(CE165669-3EF3-493F-B85D-6190EE5B9759)'

Re: [PATCH v1 0/2] ArmPkg/ArmScmiDxe: Fix a bug uncovered with the new SCP firmware

[Sudeep Holla]

Hi Girish,

On Fri, Jun 15, 2018 at 03:10:52PM +0100, Girish Pathak wrote:
> This series fixes a bug in the ArmScmiDxe which was revealed while testing
> with the new SCP firmware.
>
> The changes can be seen at https://github.com/girishpathak/edk2/tree/281_scmi_fix_v1
>

Thanks for the fix. This fixes the issue I originally reported. So, FWIW

Tested-by: Sudeep Holla <sudeep.holla@arm.com>

--
Regards,
Sudeep

Re: [PATCH v1 1/2] ArmPkg/ArmScmiDxe: Fix ASSERT error in SCMI DXE

[Ard Biesheuvel]

Hello Girish,

On 15 June 2018 at 16:10, Girish Pathak <girish.pathak@arm.com> wrote:
> This change fixes a bug in the SCMI DXE which is observed with the
> upcoming release of the SCP firmware.
>
> The PROTOCOL_ID_MASK (0xF) which is used to generate an index in
> the ProtocolInitFxns is wrong because protocol ids can be
> anywhere in 0x10 - 15 or 0x80 - FF range. This mask generates
> the same index for two different protocols e.g. for protocol ids
> 0x10 and 0x90, which causes duplicate initialization of a protocol
> resulting in a failure.
>
> This change removes the use of PROTOCOL_ID_MASK and instead
> uses a list of protocol ids and their initialization functions
> to identify a supported protocol and initialize it.
>
> Change-Id: Ib004294d2bec853045ed6e811d123832fba555cd
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Girish Pathak <girish.pathak@arm.com>
> ---
>  ArmPkg/Drivers/ArmScmiDxe/ScmiDxe.c | 35 ++++++++++----------
>  ArmPkg/Drivers/ArmScmiDxe/ScmiDxe.h |  8 +++--
>  2 files changed, 22 insertions(+), 21 deletions(-)
>
> diff --git a/ArmPkg/Drivers/ArmScmiDxe/ScmiDxe.c b/ArmPkg/Drivers/ArmScmiDxe/ScmiDxe.c
> index 2920c6f6f33c5bb8ac00c903a0b199ba5f06f4de..cc68cbc922fcc06bff8f7e0aa8b6bf64a9932874 100644
> --- a/ArmPkg/Drivers/ArmScmiDxe/ScmiDxe.c
> +++ b/ArmPkg/Drivers/ArmScmiDxe/ScmiDxe.c
> @@ -29,13 +29,10 @@
>  #include "ScmiDxe.h"
>  #include "ScmiPrivate.h"
>
> -STATIC CONST SCMI_PROTOCOL_INIT_TABLE ProtocolInitFxns[MAX_PROTOCOLS] = {
> -  { ScmiBaseProtocolInit },
> -  { NULL },
> -  { NULL },
> -  { ScmiPerformanceProtocolInit },
> -  { ScmiClockProtocolInit },
> -  { NULL }
> +STATIC CONST SCMI_PROTOCOL_ENTRY Protocols[] = {
> +  { SCMI_PROTOCOL_ID_BASE, ScmiBaseProtocolInit },
> +  { SCMI_PROTOCOL_ID_PERFORMANCE, ScmiPerformanceProtocolInit },
> +  { SCMI_PROTOCOL_ID_CLOCK, ScmiClockProtocolInit }
>  };
>
>  /** ARM SCMI driver entry point function.
> @@ -65,14 +62,14 @@ ArmScmiDxeEntryPoint (
>    UINT32              Version;
>    UINT32              Index;
>    UINT32              NumProtocols;
> -  UINT32              ProtocolNo;
> +  UINT32              ProtocolIndex = 0;

We don't permit initialized automatic variables.

>    UINT8               SupportedList[MAX_PROTOCOLS];
>    UINT32              SupportedListSize = sizeof (SupportedList);

This applies here as well, but it slipped through the cracks last
time. Care to fix this one as well? Thanks.

>
> -  ProtocolNo = SCMI_PROTOCOL_ID_BASE & PROTOCOL_ID_MASK;
> -
>    // Every SCMI implementation must implement the base protocol.
> -  Status = ProtocolInitFxns[ProtocolNo].Init (&ImageHandle);
> +  ASSERT (Protocols[ProtocolIndex].Id == SCMI_PROTOCOL_ID_BASE);
> +

Just use Protocols[0].Id here instead of obfuscating the code with a
var reference known to be == 0

> +  Status = Protocols[ProtocolIndex].InitFxn (&ImageHandle);

Same here. In fact, why not just call ScmiBaseProtocolInit() here?

>    if (EFI_ERROR (Status)) {
>      ASSERT (FALSE);
>      return Status;
> @@ -123,13 +120,15 @@ ArmScmiDxeEntryPoint (
>    }
>
>    // Install supported protocol on ImageHandle.
> -  for (Index = 0; Index < NumProtocols; Index++) {
> -    ProtocolNo = SupportedList[Index] & PROTOCOL_ID_MASK;
> -    if (ProtocolInitFxns[ProtocolNo].Init != NULL) {
> -      Status = ProtocolInitFxns[ProtocolNo].Init (&ImageHandle);
> -      if (EFI_ERROR (Status)) {
> -        ASSERT (FALSE);
> -        return Status;
> +  while (++ProtocolIndex < ARRAY_SIZE (Protocols)) {

Please use a for () loop here, including the 0 assignment that
replaces the initializer above.

> +    for (Index = 0; Index < NumProtocols; Index++) {
> +      if (Protocols[ProtocolIndex].Id == SupportedList[Index]) {
> +        Status = Protocols[ProtocolIndex].InitFxn (&ImageHandle);
> +        if (EFI_ERROR (Status)) {
> +          ASSERT (FALSE);

In general, ASSERT_EFI_ERROR () is really much more useful than ASSERT
(FALSE), because the DEBUG output will tell you the actual value of
Status. Just a tip.

> +          return Status;
> +        }
> +        break;
>        }
>      }
>    }
> diff --git a/ArmPkg/Drivers/ArmScmiDxe/ScmiDxe.h b/ArmPkg/Drivers/ArmScmiDxe/ScmiDxe.h
> index 29cdde173659c701116b021a3c437a92b473e4e5..5815e1e78074067760b6f618e248526ee25e59c8 100644
> --- a/ArmPkg/Drivers/ArmScmiDxe/ScmiDxe.h
> +++ b/ArmPkg/Drivers/ArmScmiDxe/ScmiDxe.h
> @@ -17,8 +17,9 @@
>  #ifndef SCMI_DXE_H_
>  #define SCMI_DXE_H_
>
> +#include "ScmiPrivate.h"
> +
>  #define MAX_PROTOCOLS        6
> -#define PROTOCOL_ID_MASK     0xF
>  #define MAX_VENDOR_LEN       SCMI_MAX_STR_LEN
>
>  /** Pointer to protocol initialization function.
> @@ -35,7 +36,8 @@ EFI_STATUS
>    );
>
>  typedef struct {
> -  SCMI_PROTOCOL_INIT_FXN Init;
> -} SCMI_PROTOCOL_INIT_TABLE;
> +  SCMI_PROTOCOL_ID Id;            // Protocol Id.
> +  SCMI_PROTOCOL_INIT_FXN InitFxn; // Protocol init function.

Could you replace this with InitFn please? Fxn as an abbreviation for
function is not idiomatic in any of the projects I have ever been
involved in, so let's not confuse people unnecessarily.

> +} SCMI_PROTOCOL_ENTRY;
>
>  #endif /* SCMI_DXE_H_ */
> --
> 'Guid(CE165669-3EF3-493F-B85D-6190EE5B9759)'
>
>

Re: [PATCH v1 2/2] ArmPkg/ArmScmiDxe: Dynamically allocate buffer for protocol ids

[Ard Biesheuvel]

On 15 June 2018 at 16:10, Girish Pathak <girish.pathak@arm.com> wrote:
> Dynamically allocate the buffer to receive the SCMI protocol list.
> This makes MAX_PROTOCOLS redundant, so it is removed.
> It also fixes one minor code alignment issue and removes an unused
> macro PROTOCOL_MASK.
>
> Change-Id: Idc5880d4fb7b5c674f5fb7dce1198a7cad0303a7

Can you please get rid of these change IDs? They have no meaning in
the context of the upstream repo.

> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Girish Pathak <girish.pathak@arm.com>
> ---
>  ArmPkg/Drivers/ArmScmiDxe/Scmi.c    |  5 ----
>  ArmPkg/Drivers/ArmScmiDxe/ScmiDxe.c | 27 +++++++++++++++-----
>  ArmPkg/Drivers/ArmScmiDxe/ScmiDxe.h |  1 -
>  3 files changed, 21 insertions(+), 12 deletions(-)
>
> diff --git a/ArmPkg/Drivers/ArmScmiDxe/Scmi.c b/ArmPkg/Drivers/ArmScmiDxe/Scmi.c
> index 1e279f69cf615428dbb6477b8ac7de3258628df3..d247d3a932fe9f197460a95e9afa88681742e4b4 100644
> --- a/ArmPkg/Drivers/ArmScmiDxe/Scmi.c
> +++ b/ArmPkg/Drivers/ArmScmiDxe/Scmi.c
> @@ -22,11 +22,6 @@
>
>  #include "ScmiPrivate.h"
>
> -// SCMI Specification 1.0
> -#define  MAX_PROTOCOLS       6
> -
> -#define  PROTOCOL_MASK     0xF
> -
>  // Arbitrary timeout value 20ms.
>  #define  RESPONSE_TIMEOUT  20000
>
> diff --git a/ArmPkg/Drivers/ArmScmiDxe/ScmiDxe.c b/ArmPkg/Drivers/ArmScmiDxe/ScmiDxe.c
> index cc68cbc922fcc06bff8f7e0aa8b6bf64a9932874..e7b9feca5e1b565fc031385bfe2f2dc0ca53aab0 100644
> --- a/ArmPkg/Drivers/ArmScmiDxe/ScmiDxe.c
> +++ b/ArmPkg/Drivers/ArmScmiDxe/ScmiDxe.c
> @@ -63,8 +63,8 @@ ArmScmiDxeEntryPoint (
>    UINT32              Index;
>    UINT32              NumProtocols;
>    UINT32              ProtocolIndex = 0;
> -  UINT8               SupportedList[MAX_PROTOCOLS];
> -  UINT32              SupportedListSize = sizeof (SupportedList);

Ah excellent. Forget what I said about this line in the previous message.

> +  UINT8               *SupportedList;
> +  UINT32              SupportedListSize;
>
>    // Every SCMI implementation must implement the base protocol.
>    ASSERT (Protocols[ProtocolIndex].Id == SCMI_PROTOCOL_ID_BASE);
> @@ -108,13 +108,26 @@ ArmScmiDxeEntryPoint (
>
>    ASSERT (NumProtocols != 0);
>
> +  SupportedListSize = (NumProtocols * sizeof (*SupportedList));
> +
> +  Status = gBS->AllocatePool (
> +                  EfiBootServicesData,
> +                  SupportedListSize,
> +                  (VOID**)&SupportedList
> +                  );
> +  if (EFI_ERROR (Status)) {
> +    ASSERT (FALSE);
> +    return Status;
> +  }
> +
>    // Get the list of protocols supported by SCP firmware on the platform.
>    Status = BaseProtocol->DiscoverListProtocols (
> -             BaseProtocol,
> -             &SupportedListSize,
> -             SupportedList
> -             );
> +                           BaseProtocol,
> +                           &SupportedListSize,
> +                           SupportedList
> +                           );
>    if (EFI_ERROR (Status)) {
> +    gBS->FreePool (SupportedList);
>      ASSERT (FALSE);
>      return Status;
>    }
> @@ -133,5 +146,7 @@ ArmScmiDxeEntryPoint (
>      }
>    }
>
> +  gBS->FreePool (SupportedList);
> +
>    return EFI_SUCCESS;
>  }
> diff --git a/ArmPkg/Drivers/ArmScmiDxe/ScmiDxe.h b/ArmPkg/Drivers/ArmScmiDxe/ScmiDxe.h
> index 5815e1e78074067760b6f618e248526ee25e59c8..b50a52a01d47efbbccec8c97bf44041c47ff8b38 100644
> --- a/ArmPkg/Drivers/ArmScmiDxe/ScmiDxe.h
> +++ b/ArmPkg/Drivers/ArmScmiDxe/ScmiDxe.h
> @@ -19,7 +19,6 @@
>
>  #include "ScmiPrivate.h"
>
> -#define MAX_PROTOCOLS        6
>  #define MAX_VENDOR_LEN       SCMI_MAX_STR_LEN
>
>  /** Pointer to protocol initialization function.
> --
> 'Guid(CE165669-3EF3-493F-B85D-6190EE5B9759)'
>
>