On 6 April 2016 at 22:25, Laszlo Ersek <[email protected]> wrote: > On 04/06/16 18:15, Ard Biesheuvel wrote: >> This implements a new DXE driver FdtClientDxe to produce the FDT client >> protocol based on a device tree image supplied by the virt host. >> >> Contributed-under: TianoCore Contribution Agreement 1.0 >> Signed-off-by: Ard Biesheuvel <[email protected]> >> --- >> ArmVirtPkg/FdtClientDxe/FdtClientDxe.c | 236 ++++++++++++++++++++ >> ArmVirtPkg/FdtClientDxe/FdtClientDxe.inf | 48 ++++ >> 2 files changed, 284 insertions(+) > > Starting with the INF file: > >> diff --git a/ArmVirtPkg/FdtClientDxe/FdtClientDxe.inf >> b/ArmVirtPkg/FdtClientDxe/FdtClientDxe.inf >> new file mode 100644 >> index 000000000000..55a1e680ce7c >> --- /dev/null >> +++ b/ArmVirtPkg/FdtClientDxe/FdtClientDxe.inf >> @@ -0,0 +1,48 @@ >> +## @file >> +# FDT client driver >> +# >> +# Copyright (c) 2016, Linaro Ltd. All rights reserved.<BR> >> +# >> +# This program and the accompanying materials are >> +# licensed and made available under the terms and conditions of the BSD >> License >> +# which accompanies this distribution. The full text of the license may >> be found at >> +# http://opensource.org/licenses/bsd-license.php >> +# >> +# THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, >> +# WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR >> IMPLIED. >> +# >> +## >> + >> +[Defines] >> + INF_VERSION = 0x00010005 >> + BASE_NAME = FdtClientDxe >> + FILE_GUID = 9A871B00-1C16-4F61-8D2C-93B6654B5AD6 >> + MODULE_TYPE = DXE_DRIVER >> + VERSION_STRING = 1.0 >> + ENTRY_POINT = InitializeFdtClientDxe >> + >> +[Sources] >> + FdtClientDxe.c >> + >> +[Packages] >> + MdePkg/MdePkg.dec >> + MdeModulePkg/MdeModulePkg.dec >> + ArmVirtPkg/ArmVirtPkg.dec >> + EmbeddedPkg/EmbeddedPkg.dec >> + >> +[LibraryClasses] >> + BaseLib >> + PcdLib >> + UefiDriverEntryPoint >> + FdtLib >> + HobLib >> + UefiBootServicesTableLib > > (5) For new code, please strive to keep the Packages / LibraryClasses / > etc sections in INF files sorted. First, it looks nice; second (more > importantly), it helps you verify that you list all the library classes > explicitly that you depend on. > > For example, DebugLib.h is included from the source code (correctly), > but DebugLib is not present here (it should be). The linker succeeds > because one of the library instances we depend on pulls in DebugLib > anyway, but it's not nice. Concord can be reached if the C source > includes Library/*.h headers until the compiler stops whining
I don't think minimising the set of #includes should be a goal in itself, especially since you may end up relying on transitive includes. A source file should include the header files for all functionality it pulls in from other objects. I know we still end up relying on transitive includes for things like types, and EDK2 with its AutoGen.? may supply some things implicitly as well. But in general, I don't think removing header #includes because you can is a good thing. Other than that, I agree that this should be cleaned up > (and > nothing more), and if the LibraryClasses section is consequently matched > to the include list (+ UefiDriverEntryPoint). > > Similarly, PcdLib looks superfluous. Etc. > >> + >> +[Protocols] >> + gFdtClientProtocolGuid > > (6) Please add "## PRODUCES". > OK >> + >> +[Guids] >> + gFdtHobGuid >> + >> +[Depex] >> + TRUE >> > > C file: > >> diff --git a/ArmVirtPkg/FdtClientDxe/FdtClientDxe.c >> b/ArmVirtPkg/FdtClientDxe/FdtClientDxe.c >> new file mode 100644 >> index 000000000000..716194ef798a >> --- /dev/null >> +++ b/ArmVirtPkg/FdtClientDxe/FdtClientDxe.c >> @@ -0,0 +1,236 @@ >> +/** @file >> +* FDT client driver >> +* >> +* Copyright (c) 2016, Linaro Ltd. All rights reserved.<BR> >> +* >> +* This program and the accompanying materials are >> +* licensed and made available under the terms and conditions of the BSD >> License >> +* which accompanies this distribution. The full text of the license may >> be found at >> +* http://opensource.org/licenses/bsd-license.php >> +* >> +* THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, >> +* WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR >> IMPLIED. >> +* >> +**/ >> + >> +#include <Library/BaseLib.h> >> +#include <Library/DebugLib.h> >> +#include <Library/UefiLib.h> > > (7) Can you remove BaseLib.h and UefiLib.h? Hmmm wait, BaseLib.h is > needed for AsciiStrCmp() below. > > What about UefiLib.h though? > It can be removed >> +#include <Library/UefiDriverEntryPoint.h> >> +#include <Library/UefiBootServicesTableLib.h> >> +#include <Library/HobLib.h> >> +#include <libfdt.h> >> + >> +#include <Guid/Fdt.h> > > (8) <Guid/Fdt.h> should be unnecessary. > OK >> +#include <Guid/FdtHob.h> >> + >> +#include <Protocol/FdtClient.h> >> + >> +STATIC VOID *mDeviceTreeBase; >> + >> +STATIC >> +EFI_STATUS >> +GetNodeProperty ( >> + IN FDT_CLIENT_PROTOCOL *This, >> + IN INT32 Node, >> + IN CONST CHAR8 *PropertyName, >> + OUT CONST VOID **Prop, >> + OUT UINTN *PropSize OPTIONAL >> + ) >> +{ >> + INT32 Len; >> + >> + ASSERT (mDeviceTreeBase != NULL); >> + >> + *Prop = fdt_getprop (mDeviceTreeBase, Node, PropertyName, &Len); >> + if (*Prop == NULL) { >> + return EFI_NOT_FOUND; >> + } >> + >> + if (PropSize != NULL) { >> + *PropSize = Len; > > (9) I think we can present the property size directly as UINT32 in the > protocol interface. > Indeed. Will change that. >> + } >> + return EFI_SUCCESS; >> +} >> + >> +STATIC >> +EFI_STATUS >> +SetNodeProperty ( >> + IN FDT_CLIENT_PROTOCOL *This, >> + IN INT32 Node, >> + IN CONST CHAR8 *PropertyName, >> + IN CONST VOID *Prop, >> + IN UINTN PropSize >> + ) >> +{ >> + INT32 Ret; >> + >> + ASSERT (mDeviceTreeBase != NULL); >> + >> + Ret = fdt_setprop (mDeviceTreeBase, Node, PropertyName, Prop, >> (UINT32)PropSize); > > (10) Again, I think we can expose the property size as UINT32. > Ack >> + if (Ret != 0) { >> + return EFI_DEVICE_ERROR; >> + } >> + >> + return EFI_SUCCESS; >> +} >> + >> +STATIC >> +EFI_STATUS >> +EFIAPI >> +FindCompatibleNode ( >> + IN FDT_CLIENT_PROTOCOL *This, >> + IN CONST CHAR8 *CompatibleString, >> + OUT INT32 *Node >> + ) >> +{ >> + INT32 NextNode, PrevNode; >> + CONST CHAR8 *Type, *Compatible; >> + INT32 Len; >> + >> + ASSERT (mDeviceTreeBase != NULL); >> + >> + if (Node == NULL) { >> + return EFI_INVALID_PARAMETER; >> + } > > (11) I don't mind this, but then we should be consistent about it. In > GetNodeProperty(), "Prop" is a mandatory output parameter, but you don't > validate it. > > I think it's okay to drop the check here. > OK >> + >> + for (PrevNode = 0;; PrevNode = NextNode) { >> + NextNode = fdt_next_node (mDeviceTreeBase, PrevNode, NULL); >> + if (NextNode < 0) { >> + break; >> + } >> + >> + Type = fdt_getprop (mDeviceTreeBase, NextNode, "compatible", &Len); >> + if (Type == NULL) { >> + continue; >> + } >> + >> + // >> + // A 'compatible' node may contain a sequence of NULL terminated > > (12) I realize this is being copied / reworked from VirtFdtDxe. Let's > use the opportunity to clean up things -- please replace NULL with NUL. > OK >> + // compatible strings so check each one >> + // >> + for (Compatible = Type; Compatible < Type + Len && *Compatible; >> + Compatible += 1 + AsciiStrLen (Compatible)) { >> + if (AsciiStrCmp (CompatibleString, Compatible) == 0) { >> + *Node = NextNode; >> + return EFI_SUCCESS; >> + } >> + } >> + } >> + return EFI_NOT_FOUND; >> +} >> + >> +STATIC >> +EFI_STATUS >> +EFIAPI >> +FindCompatibleNodeProperty ( >> + IN FDT_CLIENT_PROTOCOL *This, >> + IN CONST CHAR8 *CompatibleString, >> + IN CONST CHAR8 *PropertyName, >> + OUT CONST VOID **Prop, >> + OUT UINTN *PropSize OPTIONAL >> + ) >> +{ >> + EFI_STATUS Status; >> + INT32 Node; >> + >> + Status = FindCompatibleNode (This, CompatibleString, &Node); >> + if (EFI_ERROR (Status)) { >> + return Status; >> + } >> + >> + return GetNodeProperty (This, Node, PropertyName, Prop, PropSize); >> +} > > (13) Are we going to use this interface frequently? Hm... grepping the > tree in your "virt-fdt-refactor" branch, I can find four call sites. One > is just below, another one in ArmVirtPsciResetSystemLib, and the last > two in ArmVirtTimerFdtClientLib. > > I'm torn. This should be a helper function in a library. > > Meh, don't bother; keep it as-is. We can always rework this protocol if > necessary. :) > I was torn myself between putting the DT base address in a protocol and nothing else, and providing some access functions around it. I have tried to find a sweet spot where we don't duplicate too much code in the caller, and expose an abstract interface which does not allow the DT to be arbitrarily mangled. > (14) How about renaming this function (and the protocol member) to > GetCompatibleNodeProperty()? Just a suggestion, feel free to disagree. > I used Find vs Get since the former suggests that you look for something that may be anywhere, or not present at all, whereas Get suggests 'just get me the node, even if you have to create it' But as I said, I am mostly interested in the protocol dependency that this provides, and the actual interface could look wildly different for all I care. >> + >> +STATIC >> +EFI_STATUS >> +EFIAPI >> +FindCompatibleNodeReg ( >> + IN FDT_CLIENT_PROTOCOL *This, >> + IN CONST CHAR8 *CompatibleString, >> + OUT CONST VOID **Reg, >> + OUT UINTN *RegElemSize, >> + OUT UINTN *RegSize >> + ) >> +{ >> + EFI_STATUS Status; >> + >> + // >> + // Get the 'reg' property of this node. For now, we will assume >> + // 8 byte quantities for base and size, respectively. >> + // TODO use #cells root properties instead >> + // >> + Status = FindCompatibleNodeProperty (This, CompatibleString, "reg", Reg, >> RegSize); > > (15) I haven't been verifying it consistently, but this line seems too > long. > OK >> + if (EFI_ERROR (Status)) { >> + return Status; >> + } >> + >> + *RegElemSize = 8; > > (16) Can you verify that RegSize is divisible by 8? Log an error message > and return an error code if it isn't. > > Also, due to points (9) and (10), you should be able to use the % > operator for it (no need for a 64-bit wrapper function). > OK >> + >> + return EFI_SUCCESS; >> +} >> + >> +STATIC >> +EFI_STATUS >> +GetChosenNode ( >> + IN FDT_CLIENT_PROTOCOL *This, >> + OUT INT32 *Node >> + ) >> +{ >> + INT32 NewNode; >> + >> + ASSERT (mDeviceTreeBase != NULL); >> + >> + NewNode = fdt_path_offset (mDeviceTreeBase, "/chosen"); >> + if (NewNode < 0) { >> + NewNode = fdt_add_subnode (mDeviceTreeBase, 0, "/chosen"); >> + } >> + >> + if (NewNode < 0) { >> + return EFI_OUT_OF_RESOURCES; >> + } >> + >> + return EFI_SUCCESS; >> +} > > (17) Please rename this function (and the protocol member) to > GetOrInsertChosenNode(). > > In general, it wouldn't be bad if you could document all the protocol > member functions (according to the edk2 coding style, with leading > comment blocks). I don't insist (the functions are quite small), but > without such documentation, the function names become way more > important, and should be very clear. > > (Also, in my experience, writing such function comments leads to > "enlightenment" occasionally :) Opportunities for unification etc. I > can't point at any candidates in this patch; it's just a generic > remark.) > Happy to do that, but I deliberately omitted it for v1 considering the high likelihood that we ultimately end up with something completely different. >> + >> +STATIC FDT_CLIENT_PROTOCOL mFdtClientProtocol = { >> + GetNodeProperty, >> + SetNodeProperty, >> + FindCompatibleNode, >> + FindCompatibleNodeProperty, >> + FindCompatibleNodeReg, >> + GetChosenNode, >> +}; >> + >> +EFI_STATUS >> +EFIAPI >> +InitializeFdtClientDxe ( >> + IN EFI_HANDLE ImageHandle, >> + IN EFI_SYSTEM_TABLE *SystemTable >> + ) >> +{ >> + VOID *Hob; >> + VOID *DeviceTreeBase; >> + >> + Hob = GetFirstGuidHob(&gFdtHobGuid); >> + if (Hob == NULL || GET_GUID_HOB_DATA_SIZE (Hob) != sizeof (UINT64)) { >> + return EFI_NOT_FOUND; >> + } >> + DeviceTreeBase = (VOID *)(UINTN)*(UINT64 *)GET_GUID_HOB_DATA (Hob); >> + >> + if (fdt_check_header (DeviceTreeBase) != 0) { >> + DEBUG ((EFI_D_ERROR, "%a: No DTB found @ 0x%p\n", __FUNCTION__, >> DeviceTreeBase)); >> + return EFI_NOT_FOUND; >> + } > > (18) Okay, this is copied from InitializeVirtFdtDxe(). Please add a > space after "GetFirstGuidHob". > OK >> + >> + mDeviceTreeBase = DeviceTreeBase; >> + >> + DEBUG ((EFI_D_INFO, "%a: DTB @ 0x%p\n", __FUNCTION__, mDeviceTreeBase)); >> + >> + return gBS->InstallProtocolInterface ( >> + &ImageHandle, >> + &gFdtClientProtocolGuid, >> + EFI_NATIVE_INTERFACE, >> + &mFdtClientProtocol >> + ); >> +} > > (19) Please indent the arguments and the closing paren one or two colums > relative to "InstallProtocolInterface". > OK > I'll seek to continue the review tomorrow. > Thanks We haven't discussed the general goal of this series, but I assume you're on board with that, given that you are reviewing in detail already. Thanks again, Ard. _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
