Commit aadea887f4 for qemu.org

commit aadea887f4429fcc96429b126c254de94317b474
Author: Peter Maydell <peter.maydell@linaro.org>
Date:   Fri Apr 12 17:08:06 2024 +0100

    scripts/coccinelle: New script to add ResetType to hold and exit phases

    We pass a ResetType argument to the Resettable class enter phase
    method, but we don't pass it to hold and exit, even though the
    callsites have it readily available.  This means that if a device
    cared about the ResetType it would need to record it in the enter
    phase method to use later on.  We should pass the type to all three
    of the phase methods to avoid having to do that.

    This coccinelle script adds the ResetType argument to the hold and
    exit phases of the Resettable interface.

    The first part of the script (rules holdfn_assigned, holdfn_defined,
    exitfn_assigned, exitfn_defined) update implementations of the
    interface within device models, both to change the signature of their
    method implementations and to pass on the reset type when they invoke
    reset on some other device.

    The second part of the script is various special cases:
     * method callsites in resettable_phase_hold(), resettable_phase_exit()
       and device_phases_reset()
     * updating the typedefs for the methods
     * isl_pmbus_vr.c has some code where one device's reset method directly
       calls the implementation of a different device's method

    Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
    Reviewed-by: Luc Michel <luc.michel@amd.com>
    Message-id: 20240412160809.1260625-4-peter.maydell@linaro.org

diff --git a/scripts/coccinelle/reset-type.cocci b/scripts/coccinelle/reset-type.cocci
new file mode 100644
index 0000000000..14abdd7bd0
--- /dev/null
+++ b/scripts/coccinelle/reset-type.cocci
@@ -0,0 +1,133 @@
+// Convert device code using three-phase reset to add a ResetType
+// argument to implementations of ResettableHoldPhase and
+// ResettableEnterPhase methods.
+//
+// Copyright Linaro Ltd 2024
+// SPDX-License-Identifier: GPL-2.0-or-later
+//
+// for dir in include hw target; do \
+// spatch --macro-file scripts/cocci-macro-file.h \
+//        --sp-file scripts/coccinelle/reset-type.cocci \
+//        --keep-comments --smpl-spacing --in-place --include-headers \
+//        --dir $dir; done
+//
+// This coccinelle script aims to produce a complete change that needs
+// no human interaction, so as well as the generic "update device
+// implementations of the hold and exit phase methods" it includes
+// the special-case transformations needed for the core code and for
+// one device model that does something a bit nonstandard. Those
+// special cases are at the end of the file.
+
+// Look for where we use a function as a ResettableHoldPhase method,
+// either by directly assigning it to phases.hold or by calling
+// resettable_class_set_parent_phases, and remember the function name.
+@ holdfn_assigned @
+identifier enterfn, holdfn, exitfn;
+identifier rc;
+expression e;
+@@
+ResettableClass *rc;
+...
+(
+ rc->phases.hold = holdfn;
+|
+ resettable_class_set_parent_phases(rc, enterfn, holdfn, exitfn, e);
+)
+
+// Look for the definition of the function we found in holdfn_assigned,
+// and add the new argument. If the function calls a hold function
+// itself (probably chaining to the parent class reset) then add the
+// new argument there too.
+@ holdfn_defined @
+identifier holdfn_assigned.holdfn;
+typedef Object;
+identifier obj;
+expression parent;
+@@
+-holdfn(Object *obj)
++holdfn(Object *obj, ResetType type)
+{
+    <...
+-    parent.hold(obj)
++    parent.hold(obj, type)
+    ...>
+}
+
+// Similarly for ResettableExitPhase.
+@ exitfn_assigned @
+identifier enterfn, holdfn, exitfn;
+identifier rc;
+expression e;
+@@
+ResettableClass *rc;
+...
+(
+ rc->phases.exit = exitfn;
+|
+ resettable_class_set_parent_phases(rc, enterfn, holdfn, exitfn, e);
+)
+@ exitfn_defined @
+identifier exitfn_assigned.exitfn;
+typedef Object;
+identifier obj;
+expression parent;
+@@
+-exitfn(Object *obj)
++exitfn(Object *obj, ResetType type)
+{
+    <...
+-    parent.exit(obj)
++    parent.exit(obj, type)
+    ...>
+}
+
+// SPECIAL CASES ONLY BELOW HERE
+// We use a python scripted constraint on the position of the match
+// to ensure that they only match in a particular function. See
+// https://public-inbox.org/git/alpine.DEB.2.21.1808240652370.2344@hadrien/
+// which recommends this as the way to do "match only in this function".
+
+// Special case: isl_pmbus_vr.c has some reset methods calling others directly
+@ isl_pmbus_vr @
+identifier obj;
+@@
+- isl_pmbus_vr_exit_reset(obj);
++ isl_pmbus_vr_exit_reset(obj, type);
+
+// Special case: device_phases_reset() needs to pass RESET_TYPE_COLD
+@ device_phases_reset_hold @
+expression obj;
+identifier rc;
+identifier phase;
+position p : script:python() { p[0].current_element == "device_phases_reset" };
+@@
+- rc->phases.phase(obj)@p
++ rc->phases.phase(obj, RESET_TYPE_COLD)
+
+// Special case: in resettable_phase_hold() and resettable_phase_exit()
+// we need to pass through the ResetType argument to the method being called
+@ resettable_phase_hold @
+expression obj;
+identifier rc;
+position p : script:python() { p[0].current_element == "resettable_phase_hold" };
+@@
+- rc->phases.hold(obj)@p
++ rc->phases.hold(obj, type)
+@ resettable_phase_exit @
+expression obj;
+identifier rc;
+position p : script:python() { p[0].current_element == "resettable_phase_exit" };
+@@
+- rc->phases.exit(obj)@p
++ rc->phases.exit(obj, type)
+// Special case: the typedefs for the methods need to declare the new argument
+@ phase_typedef_hold @
+identifier obj;
+@@
+- typedef void (*ResettableHoldPhase)(Object *obj);
++ typedef void (*ResettableHoldPhase)(Object *obj, ResetType type);
+@ phase_typedef_exit @
+identifier obj;
+@@
+- typedef void (*ResettableExitPhase)(Object *obj);
++ typedef void (*ResettableExitPhase)(Object *obj, ResetType type);