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ArmVirtPkg: introduce FdtSerialPortAddressLib 

Introduce a new library class + instance for:

- collecting serial port base addresses from the device tree,

- collecting the /chosen stdout-path serial port base address from the
  device tree.

The logic is loosely based on the following functions:

- SerialPortGetBaseAddress()
  [ArmVirtPkg/Library/FdtPL011SerialPortLib/EarlyFdtPL011SerialPortLib.c]

- PlatformPeim() [ArmVirtPkg/Library/PlatformPeiLib/PlatformPeiLib.c]

- GetSerialConsolePortAddress()
  [ArmVirtPkg/Library/Fdt16550SerialPortHookLib/EarlyFdt16550SerialPortHookLib.c]

which are going to be converted to clients of the new library later.
Copyright notices from those other files are preserved.

The new library fixes the following warts, found by reading the existent
code:

- Neither of the three functions check whether the "reg" property exists.
  (This may be implicitly checked when they compare the property size to
  16.)

- GetSerialConsolePortAddress() uses ScanMem8() for locating a colon (":")
  node path separator in "stdout-path", when AsciiStrStr() could work just
  as fine. While ScanMem8() is likely faster, "stdout-path" is presumably
  very short, and ScanMem8() introduces an extra lib class dependency
  (namely BaseMemoryLib).

- If ScanMem8() fails to locate a colon in "stdout-path", then
  GetSerialConsolePortAddress() re-measures the length of the whole
  "stdout-path" property. This is conceptually (if not performance-wise)
  disturbing, because we know the whole size of the "stdout-path" property
  from the property lookup just before, so we only need to subtract the
  NUL-terminator for learning the length.

- GetSerialConsolePortAddress() does not check if the first (or only) node
  path inside the "stdout-path" property is empty. (Not a big deal, the
  subsequent alias resolution should simply fail.)

- GetSerialConsolePortAddress() does not verify if the node path retrieved
  (and potentially alias-resolved) from "stdout-path" can be located in
  the device tree; it assumes it.

- Code is duplicated (of course) between SerialPortGetBaseAddress() and
  PlatformPeim(), but more surprisingly, all three functions embed the
  same code for verifying the "status" property of the serial port node,
  and for checking and reading its "reg" property.

Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Leif Lindholm <quic_llindhol@quicinc.com>
Cc: Sami Mujawar <sami.mujawar@arm.com>
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20231008153912.175941-2-lersek@redhat.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=4577
[lersek@redhat.com: add TianoCore BZ reference]
This commit is contained in:
Laszlo Ersek 2023-10-08 17:39:04 +02:00 committed by mergify[bot]
parent 74c687cc2f
commit eb83b53309
5 changed files with 368 additions and 0 deletions
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1
ArmVirtPkg/ArmVirt.dsc.inc
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@ -121,6 +121,7 @@
# ARM PL011 UART Driver
PL011UartLib|ArmPlatformPkg/Library/PL011UartLib/PL011UartLib.inf
SerialPortLib|ArmVirtPkg/Library/FdtPL011SerialPortLib/FdtPL011SerialPortLib.inf
FdtSerialPortAddressLib|ArmVirtPkg/Library/FdtSerialPortAddressLib/FdtSerialPortAddressLib.inf
PeCoffExtraActionLib|ArmPkg/Library/DebugPeCoffExtraActionLib/DebugPeCoffExtraActionLib.inf
#PeCoffExtraActionLib|MdePkg/Library/BasePeCoffExtraActionLibNull/BasePeCoffExtraActionLibNull.inf

1
ArmVirtPkg/ArmVirtPkg.dec
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@ -27,6 +27,7 @@
[LibraryClasses]
ArmVirtMemInfoLib|Include/Library/ArmVirtMemInfoLib.h
FdtSerialPortAddressLib|Include/Library/FdtSerialPortAddressLib.h
[Guids.common]
gArmVirtTokenSpaceGuid = { 0x0B6F5CA7, 0x4F53, 0x445A, { 0xB7, 0x6E, 0x2E, 0x36, 0x5B, 0x80, 0x63, 0x66 } }

83
ArmVirtPkg/Include/Library/FdtSerialPortAddressLib.h Normal file
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@ -0,0 +1,83 @@
/** @file
Determine the base addresses of serial ports from the Device Tree.
Copyright (C) Red Hat
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#ifndef FDT_SERIAL_PORT_ADDRESS_LIB_H_
#define FDT_SERIAL_PORT_ADDRESS_LIB_H_
#include <Base.h>
typedef struct {
UINTN NumberOfPorts;
UINT64 BaseAddress[2];
} FDT_SERIAL_PORTS;
/**
Collect the first ARRAY_SIZE (Ports->BaseAddress) serial ports into Ports from
DeviceTree.
@param[in] DeviceTree The flat device tree (FDT) to scan.
@param[in] Compatible Look for Compatible in the "compatible" property of the
scanned nodes.
@param[out] Ports On successful return, Ports->NumberOfPorts contains the
number of serial ports found; it is (a) positive and
(b) at most ARRAY_SIZE (Ports->BaseAddress). If the FDT
had more serial ports, those are not reported. On
error, the contents of Ports are indeterminate.
@retval RETURN_INVALID_PARAMETER DeviceTree does not point to a valid FDT
header.
@retval RETURN_NOT_FOUND No compatible and enabled serial port has
been found.
@retval RETURN_SUCCESS At least one compatible and enabled serial
port has been found; Ports has been filled
in.
**/
RETURN_STATUS
EFIAPI
FdtSerialGetPorts (
IN CONST VOID *DeviceTree,
IN CONST CHAR8 *Compatible,
OUT FDT_SERIAL_PORTS *Ports
);
/**
Fetch the base address of the serial port identified in the "stdout-path"
property of the "/chosen" node in DeviceTree.
@param[in] DeviceTree The flat device tree (FDT) to scan.
@param[out] BaseAddress On success, the base address of the preferred serial
port (to be used as console). On error, BaseAddress
is not modified.
@retval RETURN_INVALID_PARAMETER DeviceTree does not point to a valid FDT
header.
@retval RETURN_NOT_FOUND No enabled console port has been found.
@retval RETURN_PROTOCOL_ERROR The first (or only) node path in the
"stdout-path" property is an empty string.
@retval RETURN_PROTOCOL_ERROR The console port has been found in the FDT,
but its base address is not correctly
represented.
@retval RETURN_SUCCESS BaseAddress has been populated.
**/
RETURN_STATUS
EFIAPI
FdtSerialGetConsolePort (
IN CONST VOID *DeviceTree,
OUT UINT64 *BaseAddress
);
#endif

256
ArmVirtPkg/Library/FdtSerialPortAddressLib/FdtSerialPortAddressLib.c Normal file
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@ -0,0 +1,256 @@
/** @file
Determine the base addresses of serial ports from the Device Tree.
Copyright (C) Red Hat
Copyright (c) 2011 - 2023, Arm Ltd. All rights reserved.<BR>
Copyright (c) 2008 - 2010, Apple Inc. All rights reserved.<BR>
Copyright (c) 2014 - 2020, Linaro Ltd. All rights reserved.<BR>
Copyright (c) 2015, Intel Corporation. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#include <Library/BaseLib.h>
#include <Library/FdtSerialPortAddressLib.h>
#include <libfdt.h>
/**
Read the "reg" property of Node in DeviceTree as a UINT64 base address.
@param[in] DeviceTree The flat device tree (FDT) to scan.
@param[in] Node The node to read the "reg" property of.
@param[out] BaseAddress On success, the base address read out of Node's "reg"
property. On error, not modified.
@retval RETURN_DEVICE_ERROR Node has a "status" property with value
different from "okay".
@retval RETURN_NOT_FOUND Node does not have a "reg" property.
@retval RETURN_BAD_BUFFER_SIZE The size of Node's "reg" property is not 16
bytes.
@retval RETURN_SUCCESS BaseAddress has been populated.
**/
STATIC
RETURN_STATUS
GetBaseAddress (
IN CONST VOID *DeviceTree,
IN INT32 Node,
OUT UINT64 *BaseAddress
)
{
CONST CHAR8 *NodeStatus;
CONST VOID *RegProp;
INT32 PropSize;
NodeStatus = fdt_getprop (DeviceTree, Node, "status", NULL);
if ((NodeStatus != NULL) && (AsciiStrCmp (NodeStatus, "okay") != 0)) {
return RETURN_DEVICE_ERROR;
}
RegProp = fdt_getprop (DeviceTree, Node, "reg", &PropSize);
if (RegProp == NULL) {
return RETURN_NOT_FOUND;
}
if (PropSize != 16) {
return RETURN_BAD_BUFFER_SIZE;
}
*BaseAddress = fdt64_to_cpu (ReadUnaligned64 (RegProp));
return RETURN_SUCCESS;
}
/**
Collect the first ARRAY_SIZE (Ports->BaseAddress) serial ports into Ports from
DeviceTree.
@param[in] DeviceTree The flat device tree (FDT) to scan.
@param[in] Compatible Look for Compatible in the "compatible" property of the
scanned nodes.
@param[out] Ports On successful return, Ports->NumberOfPorts contains the
number of serial ports found; it is (a) positive and
(b) at most ARRAY_SIZE (Ports->BaseAddress). If the FDT
had more serial ports, those are not reported. On
error, the contents of Ports are indeterminate.
@retval RETURN_INVALID_PARAMETER DeviceTree does not point to a valid FDT
header.
@retval RETURN_NOT_FOUND No compatible and enabled serial port has
been found.
@retval RETURN_SUCCESS At least one compatible and enabled serial
port has been found; Ports has been filled
in.
**/
RETURN_STATUS
EFIAPI
FdtSerialGetPorts (
IN CONST VOID *DeviceTree,
IN CONST CHAR8 *Compatible,
OUT FDT_SERIAL_PORTS *Ports
)
{
INT32 Node;
if (fdt_check_header (DeviceTree) != 0) {
return RETURN_INVALID_PARAMETER;
}
Ports->NumberOfPorts = 0;
Node = fdt_next_node (DeviceTree, 0, NULL);
while ((Node > 0) &&
(Ports->NumberOfPorts < ARRAY_SIZE (Ports->BaseAddress)))
{
CONST CHAR8 *CompatProp;
INT32 PropSize;
CompatProp = fdt_getprop (DeviceTree, Node, "compatible", &PropSize);
if (CompatProp != NULL) {
CONST CHAR8 *CompatItem;
CompatItem = CompatProp;
while ((CompatItem < CompatProp + PropSize) &&
(AsciiStrCmp (CompatItem, Compatible) != 0))
{
CompatItem += AsciiStrLen (CompatItem) + 1;
}
if (CompatItem < CompatProp + PropSize) {
RETURN_STATUS Status;
UINT64 BaseAddress;
Status = GetBaseAddress (DeviceTree, Node, &BaseAddress);
if (!RETURN_ERROR (Status)) {
Ports->BaseAddress[Ports->NumberOfPorts++] = BaseAddress;
}
}
}
Node = fdt_next_node (DeviceTree, Node, NULL);
}
return Ports->NumberOfPorts > 0 ? RETURN_SUCCESS : RETURN_NOT_FOUND;
}
/**
Fetch the base address of the serial port identified in the "stdout-path"
property of the "/chosen" node in DeviceTree.
@param[in] DeviceTree The flat device tree (FDT) to scan.
@param[out] BaseAddress On success, the base address of the preferred serial
port (to be used as console). On error, BaseAddress
is not modified.
@retval RETURN_INVALID_PARAMETER DeviceTree does not point to a valid FDT
header.
@retval RETURN_NOT_FOUND No enabled console port has been found.
@retval RETURN_PROTOCOL_ERROR The first (or only) node path in the
"stdout-path" property is an empty string.
@retval RETURN_PROTOCOL_ERROR The console port has been found in the FDT,
but its base address is not correctly
represented.
@retval RETURN_SUCCESS BaseAddress has been populated.
**/
RETURN_STATUS
EFIAPI
FdtSerialGetConsolePort (
IN CONST VOID *DeviceTree,
OUT UINT64 *BaseAddress
)
{
INT32 ChosenNode;
CONST CHAR8 *StdoutPathProp;
INT32 PropSize;
CONST CHAR8 *StdoutPathEnd;
UINTN StdoutPathLength;
INT32 ConsoleNode;
RETURN_STATUS Status;
if (fdt_check_header (DeviceTree) != 0) {
return RETURN_INVALID_PARAMETER;
}
ChosenNode = fdt_path_offset (DeviceTree, "/chosen");
if (ChosenNode < 0) {
return RETURN_NOT_FOUND;
}
StdoutPathProp = fdt_getprop (
DeviceTree,
ChosenNode,
"stdout-path",
&PropSize
);
if (StdoutPathProp == NULL) {
return RETURN_NOT_FOUND;
}
//
// If StdoutPathProp contains a colon (":"), then the colon terminates the
// path we're interested in.
//
StdoutPathEnd = AsciiStrStr (StdoutPathProp, ":");
if (StdoutPathEnd == NULL) {
StdoutPathLength = PropSize - 1;
} else {
StdoutPathLength = StdoutPathEnd - StdoutPathProp;
}
if (StdoutPathLength == 0) {
return RETURN_PROTOCOL_ERROR;
}
if (StdoutPathProp[0] == '/') {
//
// StdoutPathProp starts with an absolute node path.
//
ConsoleNode = fdt_path_offset_namelen (
DeviceTree,
StdoutPathProp,
(INT32)StdoutPathLength
);
} else {
//
// StdoutPathProp starts with an alias.
//
CONST CHAR8 *ResolvedStdoutPath;
ResolvedStdoutPath = fdt_get_alias_namelen (
DeviceTree,
StdoutPathProp,
(INT32)StdoutPathLength
);
if (ResolvedStdoutPath == NULL) {
return RETURN_NOT_FOUND;
}
ConsoleNode = fdt_path_offset (DeviceTree, ResolvedStdoutPath);
}
if (ConsoleNode < 0) {
return RETURN_NOT_FOUND;
}
Status = GetBaseAddress (DeviceTree, ConsoleNode, BaseAddress);
switch (Status) {
case RETURN_NOT_FOUND:
case RETURN_BAD_BUFFER_SIZE:
return RETURN_PROTOCOL_ERROR;
case RETURN_SUCCESS:
return RETURN_SUCCESS;
default:
return RETURN_NOT_FOUND;
}
}

27
ArmVirtPkg/Library/FdtSerialPortAddressLib/FdtSerialPortAddressLib.inf Normal file
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@ -0,0 +1,27 @@
## @file
# Determine the base addresses of serial ports from the Device Tree.
#
# Copyright (C) Red Hat
#
# SPDX-License-Identifier: BSD-2-Clause-Patent
##
[Defines]
INF_VERSION = 1.27
BASE_NAME = FdtSerialPortAddressLib
FILE_GUID = AEBE813B-25EA-40E5-95C4-2B864FE1E951
MODULE_TYPE = BASE
VERSION_STRING = 1.0
LIBRARY_CLASS = FdtSerialPortAddressLib
[Sources]
FdtSerialPortAddressLib.c
[Packages]
ArmVirtPkg/ArmVirtPkg.dec
EmbeddedPkg/EmbeddedPkg.dec
MdePkg/MdePkg.dec
[LibraryClasses]
BaseLib
FdtLib