On Friday, September 23, 2016 11:26:26 AM Lv Zheng wrote:
> After fixing ACPICA internal locking issues, we can enable the correct
> grammar support for the table loading. The new grammar treats the entire
> table as TermList rather than ObjectList, thus the module level code should
> be executed right in place.
>
> MLC (module level code) is an ACPICA terminology describing the AML code
> out of any control method, currently only Type1Opcode (If/Else/While)
> wrapped MLC code blocks are executed by the AML interpreter after the table
> loading. But the issue which is fixed by this patchset is:
> Not only Type1Opcode, but also Type2Opcode will be executed as MLC and
> MLC is not defer-executed after loading the table, but is executed right
> in place.
>
> The following AML code is assembled into a static loading SSDT, and used
> as an instrumentation to pry into the de-facto standard AML interpreter
> behaviors:
> Name (ECOK, Zero)
> Scope (\)
> {
> DBUG ("TermList 1")
> If (LEqual (ECOK, Zero))
> {
> DBUG ("TermList 2")
> Device (MDEV)
> {
> DEBUG (TermList 3")
> If (CondRefOf (MDEV))
> {
> DBUG ("MDEV exists")
> }
> If (CondRefOf (MDEV._STA))
> {
> DBUG ("MDEV._STA exists")
> }
> If (CondRefOf (\_SB.PCI0.EC))
> {
> DBUG ("\\_SB.PCI0.EC exists")
> }
> Name (_HID, EisaId ("PNP9999"))
> Method (_STA, 0, Serialized)
> {
> DEBUG ("\\_SB.MDEV._STA")
> Return (0x0F)
> }
> }
> DBUG ("TermList 4")
> }
> Method (_INI, 0, Serialized)
> {
> DBUG ("\\_SB._INI")
> }
> }
> Scope (_SB.PCI0)
> {
> Device (EC)
> {
> ...
> }
> }
> The DBUG function is a function to write the debugging messages into a
> SystemIo debug port.
> Running Windows with the BIOS providing this SSDT via RSDT, the following
> messages are obtained from the debug port:
> TermList 1
> TermList 2
> TermList 3
> \_SB.MDEV exists
> TermList 4
> \_SB._INI
> ...
>
> This test reveals the de-facto grammar for the AMLCode to us:
> 1. During the table loading, MLC will be executed by the interpreter, this
> is partially supported by the current ACPICA;
> 2. For SystemIo, not only after the _REG(1, 1) is evaluated (current ACPICA
> interpreter limitation), but when the table is being loaded, the
> SystemIo (the debugging port) is accessible, this is recently fixed in
> the upstream, now all early operation regions are accessible during the
> table loading;
> 3. Not only Type1Opcode, but also Type2Opcode will be executed as MLC and
> MLC is not executed after loading the table, but is executed right in
> place, the Linux upstream is not compliant to this behavior.
>
> The last compliance issue has already been clarified in ACPI 2.0
> specification, so the compliance issue is not that Linux is not compliant
> to the de-facto standard OS, but that Linux is not compliant to ACPI 2.0.
> Definition block tables in fact is defined by the spec as TermList, which
> has no difference than the control methods, thus the interpretion of the
> table should be no difference that the control method evaluation:
> AMLCode := DefBlockHeader TermList
> DefMethod := MethodOp PkgLength NameString MethodFlags TermList
> Now the new upcoming ACPI specification has been clarified around the above
> grammar primitives, so we need to implement them for Linux.
>
> This patchset also contains 2 required fixes generated to fix the
> regressions detected by the ACPICA ASLTS tool. The ASLTS 'table' test suite
> has detected such regressions. The fixes have been accepted by the ACPICA
> upstream (please refer to the ACPICA upstream URL in the description of the
> 2 patches). And they are sent to Linux community as urgent materials along
> with the module level code enabling series. With the additional regression
> fixes, new grammar changes have passed all ASLTS 'table' cases:
> https://bugs.acpica.org/show_bug.cgi?id=1327
> https://github.com/acpica/acpica/pull/177
>
> Lv Zheng (5):
> ACPICA: Tables: Fix "UNLOAD" code path lock issues
> ACPICA: Parser: Fix a regression in LoadTable support
> ACPI 2.0 / AML: Enable correct ACPI subsystem initialization order
> for new table loading mode
> ACPI 2.0 / AML: Improve module level execution by moving the
> If/Else/While execution to per-table basis
> ACPI 2.0 / AML: Fix module level execution by correctly parsing table
> as TermList
[1-2/5] queued up for 4.9.
The rest I'd prefer to keep in linux-next for some time before they go in,
so let's make them 4.10 material if not urgent for some reasons.
Thanks,
Rafael
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