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From: "Pete Batard" <pete@akeo.ie>
To: devel@edk2.groups.io
Cc: ard.biesheuvel@arm.com, leif@nuviainc.com, awarkentin@vmware.com,
	Andrei Warkentin <andrey.warkentin@gmail.com>
Subject: [edk2-platforms][PATCH 1/3] Platform/RPi: Fortify mailbox code
Date: Mon,  4 May 2020 12:15:46 +0100	[thread overview]
Message-ID: <20200504111548.11112-2-pete@akeo.ie> (raw)
In-Reply-To: <20200504111548.11112-1-pete@akeo.ie>

From: Andrei Warkentin <andrey.warkentin@gmail.com>

As part of the analysis done in:
https://github.com/raspberrypi/firmware/issues/1376:
* Bump up max tries, to avoid command time-outs.
* Macro-ify RaspberryPiHelper.S some more to make code more maintainable.
* Add ".align 4" before every command buffer.

Co-authored-by: Pete Batard <pete@akeo.ie>
Co-authored-by: Andrei Warkentin <andrey.warkentin@gmail.com>
Signed-off-by: Pete Batard <pete@akeo.ie>
---
 Platform/RaspberryPi/Drivers/RpiFirmwareDxe/RpiFirmwareDxe.c         | 11 +---
 Platform/RaspberryPi/Include/IndustryStandard/RpiMbox.h              | 11 +++-
 Platform/RaspberryPi/Library/PlatformLib/AArch64/RaspberryPiHelper.S | 60 ++++++++------------
 3 files changed, 37 insertions(+), 45 deletions(-)

diff --git a/Platform/RaspberryPi/Drivers/RpiFirmwareDxe/RpiFirmwareDxe.c b/Platform/RaspberryPi/Drivers/RpiFirmwareDxe/RpiFirmwareDxe.c
index 40c78b5d57cf..6c45cf47f082 100644
--- a/Platform/RaspberryPi/Drivers/RpiFirmwareDxe/RpiFirmwareDxe.c
+++ b/Platform/RaspberryPi/Drivers/RpiFirmwareDxe/RpiFirmwareDxe.c
@@ -1,5 +1,6 @@
 /** @file
  *
+ *  Copyright (c) 2020, Pete Batard <pete@akeo.ie>
  *  Copyright (c) 2019, ARM Limited. All rights reserved.
  *  Copyright (c) 2017-2018, Andrei Warkentin <andrey.warkentin@gmail.com>
  *  Copyright (c) 2016, Linaro, Ltd. All rights reserved.
@@ -30,12 +31,6 @@
 //
 #define NUM_PAGES   1
 
-//
-// The number of iterations to perform when waiting for the mailbox
-// status to change
-//
-#define MAX_TRIES   0x100000
-
 STATIC VOID  *mDmaBuffer;
 STATIC VOID  *mDmaBufferMapping;
 STATIC UINTN mDmaBufferBusAddress;
@@ -62,7 +57,7 @@ DrainMailbox (
     }
     ArmDataSynchronizationBarrier ();
     MmioRead32 (BCM2836_MBOX_BASE_ADDRESS + BCM2836_MBOX_READ_OFFSET);
-  } while (++Tries < MAX_TRIES);
+  } while (++Tries < RPI_MBOX_MAX_TRIES);
 
   return FALSE;
 }
@@ -86,7 +81,7 @@ MailboxWaitForStatusCleared (
       return TRUE;
     }
     ArmDataSynchronizationBarrier ();
-  } while (++Tries < MAX_TRIES);
+  } while (++Tries < RPI_MBOX_MAX_TRIES);
 
   return FALSE;
 }
diff --git a/Platform/RaspberryPi/Include/IndustryStandard/RpiMbox.h b/Platform/RaspberryPi/Include/IndustryStandard/RpiMbox.h
index 584786a61dfd..3328be582df1 100644
--- a/Platform/RaspberryPi/Include/IndustryStandard/RpiMbox.h
+++ b/Platform/RaspberryPi/Include/IndustryStandard/RpiMbox.h
@@ -1,6 +1,6 @@
 /** @file
  *
- * Copyright (c) 2019, Pete Batard <pete@akeo.ie>
+ * Copyright (c) 2019-2020, Pete Batard <pete@akeo.ie>
  * Copyright (c) 2016, Linaro Limited. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-2-Clause-Patent
@@ -10,6 +10,15 @@
 #ifndef __RASPBERRY_PI_MAILBOX_H__
 #define __RASPBERRY_PI_MAILBOX_H__
 
+/*
+ * Number of iterations to perform when waiting for the mailbox.
+ *
+ * This number was arrived at empirically, following discussion
+ * at https://github.com/raspberrypi/firmware/issues/1376, to
+ * avoid mailbox time-outs on some commands.
+ */
+#define RPI_MBOX_MAX_TRIES                                    0x8000000
+
 /* Mailbox channels */
 #define RPI_MBOX_PM_CHANNEL                                   0
 #define RPI_MBOX_FB_CHANNEL                                   1
diff --git a/Platform/RaspberryPi/Library/PlatformLib/AArch64/RaspberryPiHelper.S b/Platform/RaspberryPi/Library/PlatformLib/AArch64/RaspberryPiHelper.S
index cc58406e1bfc..91dfe1bb981e 100644
--- a/Platform/RaspberryPi/Library/PlatformLib/AArch64/RaspberryPiHelper.S
+++ b/Platform/RaspberryPi/Library/PlatformLib/AArch64/RaspberryPiHelper.S
@@ -1,6 +1,7 @@
 /** @file
  *
- *  Copyright (c) 2019, Pete Batard <pete@akeo.ie>
+ *  Copyright (c) 2020, Andrei Warkentin <andrey.warkentin@gmail.com>
+ *  Copyright (c) 2019-2020, Pete Batard <pete@akeo.ie>
  *  Copyright (c) 2016, Linaro Limited. All rights reserved.
  *  Copyright (c) 2011-2013, ARM Limited. All rights reserved.
  *
@@ -13,10 +14,8 @@
 #include <IndustryStandard/Bcm2836.h>
 #include <IndustryStandard/RpiMbox.h>
 
-#define MAX_TRIES     0x100000
-
     .macro  drain
-    mov     x5, #MAX_TRIES
+    mov     x5, #RPI_MBOX_MAX_TRIES
 0:  ldr     w6, [x4, #BCM2836_MBOX_STATUS_OFFSET]
     tbnz    w6, #BCM2836_MBOX_STATUS_EMPTY, 1f
     dmb     ld
@@ -27,7 +26,7 @@
     .endm
 
     .macro  poll, status
-    mov     x5, #MAX_TRIES
+    mov     x5, #RPI_MBOX_MAX_TRIES
 0:  ldr     w6, [x4, #BCM2836_MBOX_STATUS_OFFSET]
     tbz     w6, #\status, 1f
     dmb     ld
@@ -36,23 +35,30 @@
 1:
     .endm
 
+    .macro  run, command_buffer
+    adr     x0, \command_buffer
+    orr     x0, x0, #RPI_MBOX_VC_CHANNEL
+    add     x0, x0, x1
+
+    poll    BCM2836_MBOX_STATUS_FULL
+    str     w0, [x4, #BCM2836_MBOX_WRITE_OFFSET]
+    dmb     sy
+    poll    BCM2836_MBOX_STATUS_EMPTY
+    dmb     sy
+    ldr     wzr, [x4, #BCM2836_MBOX_READ_OFFSET]
+    dmb     ld
+    .endm
+
 ASM_FUNC (ArmPlatformPeiBootAction)
-    adr     x0, .Lmeminfo_buffer
     mov     x1, #FixedPcdGet64 (PcdDmaDeviceOffset)
     orr     x0, x0, #RPI_MBOX_VC_CHANNEL
     // x1 holds the value of PcdDmaDeviceOffset throughout this function
-    add     x0, x0, x1
 
     MOV32   (x4, BCM2836_MBOX_BASE_ADDRESS)
 
     drain
-    poll    BCM2836_MBOX_STATUS_FULL
-    str     w0, [x4, #BCM2836_MBOX_WRITE_OFFSET]
-    dmb     sy
-    poll    BCM2836_MBOX_STATUS_EMPTY
-    dmb     sy
-    ldr     wzr, [x4, #BCM2836_MBOX_READ_OFFSET]
-    dmb     ld
+
+    run     .Lmeminfo_buffer
 
     ldr     w0, .Lmembase
     adr     x2, mSystemMemoryBase
@@ -63,17 +69,7 @@ ASM_FUNC (ArmPlatformPeiBootAction)
     adr     x2, mSystemMemoryEnd
     str     x0, [x2]
 
-    adr     x0, .Lvcinfo_buffer
-    orr     x0, x0, #RPI_MBOX_VC_CHANNEL
-    add     x0, x0, x1
-
-    poll    BCM2836_MBOX_STATUS_FULL
-    str     w0, [x4, #BCM2836_MBOX_WRITE_OFFSET]
-    dmb     sy
-    poll    BCM2836_MBOX_STATUS_EMPTY
-    dmb     sy
-    ldr     wzr, [x4, #BCM2836_MBOX_READ_OFFSET]
-    dmb     ld
+    run     .Lvcinfo_buffer
 
     ldr     w0, .Lvcbase
     adr     x2, mVideoCoreBase
@@ -83,17 +79,7 @@ ASM_FUNC (ArmPlatformPeiBootAction)
     adr     x2, mVideoCoreSize
     str     x0, [x2]
 
-    adr     x0, .Lrevinfo_buffer
-    orr     x0, x0, #RPI_MBOX_VC_CHANNEL
-    add     x0, x0, x1
-
-    poll    BCM2836_MBOX_STATUS_FULL
-    str     w0, [x4, #BCM2836_MBOX_WRITE_OFFSET]
-    dmb     sy
-    poll    BCM2836_MBOX_STATUS_EMPTY
-    dmb     sy
-    ldr     wzr, [x4, #BCM2836_MBOX_READ_OFFSET]
-    dmb     ld
+    run     .Lrevinfo_buffer
 
     ldr     w0, .Lrevision
     adr     x2, mBoardRevision
@@ -115,6 +101,7 @@ ASM_FUNC (ArmPlatformPeiBootAction)
     .long   0                           // end tag
     .set    .Lmeminfo_size, . - .Lmeminfo_buffer
 
+    .align  4
 .Lvcinfo_buffer:
     .long   .Lvcinfo_size
     .long   0x0
@@ -128,6 +115,7 @@ ASM_FUNC (ArmPlatformPeiBootAction)
     .long   0                           // end tag
     .set    .Lvcinfo_size, . - .Lvcinfo_buffer
 
+    .align  4
 .Lrevinfo_buffer:
     .long   .Lrevinfo_size
     .long   0x0
-- 
2.21.0.windows.1


  reply	other threads:[~2020-05-04 11:16 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-04 11:15 [edk2-platforms][PATCH 0/3] Platform/RPi: Fix compatibility with recent start.elf Pete Batard
2020-05-04 11:15 ` Pete Batard [this message]
2020-05-06 12:39   ` [edk2-platforms][PATCH 1/3] Platform/RPi: Fortify mailbox code Ard Biesheuvel
2020-05-04 11:15 ` [edk2-platforms][PATCH 2/3] Platform/RPi/DualSerialPortLib: Fix miniUART serial divisor computation Pete Batard
2020-05-05 10:05   ` Ard Biesheuvel
2020-05-05 11:54     ` Pete Batard
2020-05-05 12:05       ` Ard Biesheuvel
2020-05-05 12:09         ` Pete Batard
2020-05-04 11:15 ` [edk2-platforms][PATCH 3/3] Platform/RPi: Report core clock frequency during early init Pete Batard
2020-05-04 11:37   ` [edk2-devel] " Philippe Mathieu-Daudé
2020-05-05  6:04   ` Andrei Warkentin

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