From 27600805e62f800bacf990354632eae4e487d34c Mon Sep 17 00:00:00 2001
From: Yazen Ghannam <yazen.ghannam@amd.com>
Date: Thu, 3 Sep 2026 10:43:25 -0500
Subject: x86/amd_node: Fix PCI device reference counting in amd_smn_init()

The local "root" pointer is a temporary variable used during the device
search. Therefore, refcount related to the search iterators should be cleaned
up after the search is complete.

Use the __free() cleanup macro to ensure the refcount is decremented when the
temporary pointer goes out of scope.

Additionally, increment the refcount when caching a root pointer. This ensures
the in-use refcount is separate from the temporary search refcounting.

Finally, drop the redundant "root = NULL" before the second search loop. The
pci_get_class() iterator always decrements the refcount of its "from"
argument, so the first loop can only fall through with "root" already NULL.

Fixes: 0a4b61d9c2e4 ("x86/amd_node: Fix AMD root device caching")
Closes: https://sashiko.dev/#/patchset/20260806160159.230453-1-jason.andryuk%40amd.com
Reported-by: Sashiko <sashiko-bot@kernel.org>
Assisted-by: LLM
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Cc: <stable@kernel.org>
Link: https://patch.msgid.link/20260903154325.74343-1-yazen.ghannam@amd.com
---
 rust/bindings/bindings_helper.h | 172 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 172 insertions(+)
 create mode 100644 rust/bindings/bindings_helper.h

(limited to 'rust/bindings/bindings_helper.h')

diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h
new file mode 100644
index 000000000..4b31aa7f4
--- /dev/null
+++ b/rust/bindings/bindings_helper.h
@@ -0,0 +1,172 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Header that contains the code (mostly headers) for which Rust bindings
+ * will be automatically generated by `bindgen`.
+ *
+ * Sorted alphabetically.
+ */
+
+/*
+ * First, avoid forward references to `enum` types.
+ *
+ * This workarounds a `bindgen` issue with them:
+ * <https://github.com/rust-lang/rust-bindgen/issues/3179>.
+ *
+ * Without this, the generated Rust type may be the wrong one (`i32`) or
+ * the proper one (typically `c_uint`) depending on how the headers are
+ * included, which in turn may depend on the particular kernel configuration
+ * or the architecture.
+ *
+ * The alternative would be to use casts and likely an
+ * `#[allow(clippy::unnecessary_cast)]` in the Rust source files. Instead,
+ * this approach allows us to keep the correct code in the source files and
+ * simply remove this section when the issue is fixed upstream and we bump
+ * the minimum `bindgen` version.
+ *
+ * This workaround may not be possible in some cases, depending on how the C
+ * headers are set up.
+ */
+#include <linux/hrtimer_types.h>
+
+#include <linux/acpi.h>
+#include <linux/gpu_buddy.h>
+#include <drm/drm_device.h>
+#include <drm/drm_drv.h>
+#include <drm/drm_file.h>
+#include <drm/drm_gem.h>
+#include <drm/drm_gem_shmem_helper.h>
+#include <drm/drm_gpuvm.h>
+#include <drm/drm_ioctl.h>
+#include <kunit/test.h>
+#include <linux/auxiliary_bus.h>
+#include <linux/bitmap.h>
+#include <linux/blk-mq.h>
+#include <linux/blk_types.h>
+#include <linux/blkdev.h>
+#include <linux/clk.h>
+#include <linux/completion.h>
+#include <linux/configfs.h>
+#include <linux/cpu.h>
+#include <linux/cpufreq.h>
+#include <linux/cpumask.h>
+#include <linux/cred.h>
+#include <linux/debugfs.h>
+#include <linux/device/faux.h>
+#include <linux/dma-direction.h>
+#include <linux/dma-mapping.h>
+#include <linux/dma-resv.h>
+#include <linux/errname.h>
+#include <linux/ethtool.h>
+#include <linux/fdtable.h>
+#include <linux/file.h>
+#include <linux/firmware.h>
+#include <linux/fwctl.h>
+#include <linux/fs.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/io-pgtable.h>
+#include <linux/ioport.h>
+#include <linux/iosys-map.h>
+#include <linux/jiffies.h>
+#include <linux/jump_label.h>
+#include <linux/mdio.h>
+#include <linux/mm.h>
+#include <linux/miscdevice.h>
+#include <linux/of_device.h>
+#include <linux/pci.h>
+#include <linux/phy.h>
+#include <linux/pid_namespace.h>
+#include <linux/platform_device.h>
+#include <linux/pm_opp.h>
+#include <linux/poll.h>
+#include <linux/property.h>
+#include <linux/pwm.h>
+#include <linux/random.h>
+#include <linux/refcount.h>
+#include <linux/regulator/consumer.h>
+#include <linux/sched.h>
+#include <linux/security.h>
+#include <linux/serdev.h>
+#include <linux/slab.h>
+#include <linux/sys_soc.h>
+#include <linux/task_work.h>
+#include <linux/tracepoint.h>
+#include <linux/usb.h>
+#include <linux/wait.h>
+#include <linux/workqueue.h>
+#include <linux/xarray.h>
+#include <net/genetlink.h>
+#include <net/netlink.h>
+#include <trace/events/rust_sample.h>
+
+/*
+ * The driver-core Rust code needs to know about some C driver-core private
+ * structures.
+ */
+#include <../../drivers/base/base.h>
+
+#if defined(CONFIG_DRM_PANIC_SCREEN_QR_CODE)
+// Used by `#[export]` in `drivers/gpu/drm/drm_panic_qr.rs`.
+#include <drm/drm_panic.h>
+#endif
+
+/* `bindgen` gets confused at certain things. */
+const size_t RUST_CONST_HELPER_ARCH_SLAB_MINALIGN = ARCH_SLAB_MINALIGN;
+const size_t RUST_CONST_HELPER_ARCH_KMALLOC_MINALIGN = ARCH_KMALLOC_MINALIGN;
+const size_t RUST_CONST_HELPER_PAGE_SIZE = PAGE_SIZE;
+const size_t RUST_CONST_HELPER_GENLMSG_DEFAULT_SIZE = GENLMSG_DEFAULT_SIZE;
+const gfp_t RUST_CONST_HELPER_GFP_ATOMIC = GFP_ATOMIC;
+const gfp_t RUST_CONST_HELPER_GFP_KERNEL = GFP_KERNEL;
+const gfp_t RUST_CONST_HELPER_GFP_KERNEL_ACCOUNT = GFP_KERNEL_ACCOUNT;
+const gfp_t RUST_CONST_HELPER_GFP_NOWAIT = GFP_NOWAIT;
+const gfp_t RUST_CONST_HELPER___GFP_ZERO = __GFP_ZERO;
+const gfp_t RUST_CONST_HELPER___GFP_HIGHMEM = ___GFP_HIGHMEM;
+const gfp_t RUST_CONST_HELPER___GFP_NOWARN = ___GFP_NOWARN;
+const blk_features_t RUST_CONST_HELPER_BLK_FEAT_ROTATIONAL = BLK_FEAT_ROTATIONAL;
+const fop_flags_t RUST_CONST_HELPER_FOP_UNSIGNED_OFFSET = FOP_UNSIGNED_OFFSET;
+
+const xa_mark_t RUST_CONST_HELPER_XA_PRESENT = XA_PRESENT;
+
+const gfp_t RUST_CONST_HELPER_XA_FLAGS_ALLOC = XA_FLAGS_ALLOC;
+const gfp_t RUST_CONST_HELPER_XA_FLAGS_ALLOC1 = XA_FLAGS_ALLOC1;
+
+const vm_flags_t RUST_CONST_HELPER_VM_MERGEABLE = VM_MERGEABLE;
+const vm_flags_t RUST_CONST_HELPER_VM_READ = VM_READ;
+const vm_flags_t RUST_CONST_HELPER_VM_WRITE = VM_WRITE;
+const vm_flags_t RUST_CONST_HELPER_VM_EXEC = VM_EXEC;
+const vm_flags_t RUST_CONST_HELPER_VM_SHARED = VM_SHARED;
+const vm_flags_t RUST_CONST_HELPER_VM_MAYREAD = VM_MAYREAD;
+const vm_flags_t RUST_CONST_HELPER_VM_MAYWRITE = VM_MAYWRITE;
+const vm_flags_t RUST_CONST_HELPER_VM_MAYEXEC = VM_MAYEXEC;
+const vm_flags_t RUST_CONST_HELPER_VM_MAYSHARE = VM_MAYEXEC;
+const vm_flags_t RUST_CONST_HELPER_VM_PFNMAP = VM_PFNMAP;
+const vm_flags_t RUST_CONST_HELPER_VM_IO = VM_IO;
+const vm_flags_t RUST_CONST_HELPER_VM_DONTCOPY = VM_DONTCOPY;
+const vm_flags_t RUST_CONST_HELPER_VM_DONTEXPAND = VM_DONTEXPAND;
+const vm_flags_t RUST_CONST_HELPER_VM_LOCKONFAULT = VM_LOCKONFAULT;
+const vm_flags_t RUST_CONST_HELPER_VM_ACCOUNT = VM_ACCOUNT;
+const vm_flags_t RUST_CONST_HELPER_VM_NORESERVE = VM_NORESERVE;
+const vm_flags_t RUST_CONST_HELPER_VM_HUGETLB = VM_HUGETLB;
+const vm_flags_t RUST_CONST_HELPER_VM_SYNC = VM_SYNC;
+const vm_flags_t RUST_CONST_HELPER_VM_ARCH_1 = VM_ARCH_1;
+const vm_flags_t RUST_CONST_HELPER_VM_WIPEONFORK = VM_WIPEONFORK;
+const vm_flags_t RUST_CONST_HELPER_VM_DONTDUMP = VM_DONTDUMP;
+const vm_flags_t RUST_CONST_HELPER_VM_SOFTDIRTY = VM_SOFTDIRTY;
+const vm_flags_t RUST_CONST_HELPER_VM_MIXEDMAP = VM_MIXEDMAP;
+const vm_flags_t RUST_CONST_HELPER_VM_HUGEPAGE = VM_HUGEPAGE;
+const vm_flags_t RUST_CONST_HELPER_VM_NOHUGEPAGE = VM_NOHUGEPAGE;
+
+#if IS_ENABLED(CONFIG_GPU_BUDDY)
+const unsigned long RUST_CONST_HELPER_GPU_BUDDY_RANGE_ALLOCATION = GPU_BUDDY_RANGE_ALLOCATION;
+const unsigned long RUST_CONST_HELPER_GPU_BUDDY_TOPDOWN_ALLOCATION = GPU_BUDDY_TOPDOWN_ALLOCATION;
+const unsigned long RUST_CONST_HELPER_GPU_BUDDY_CONTIGUOUS_ALLOCATION =
+								GPU_BUDDY_CONTIGUOUS_ALLOCATION;
+const unsigned long RUST_CONST_HELPER_GPU_BUDDY_CLEAR_ALLOCATION = GPU_BUDDY_CLEAR_ALLOCATION;
+const unsigned long RUST_CONST_HELPER_GPU_BUDDY_CLEARED = GPU_BUDDY_CLEARED;
+const unsigned long RUST_CONST_HELPER_GPU_BUDDY_TRIM_DISABLE = GPU_BUDDY_TRIM_DISABLE;
+#endif
+
+#if IS_ENABLED(CONFIG_ANDROID_BINDER_IPC_RUST)
+#include "../../drivers/android/binder/rust_binder.h"
+#include "../../drivers/android/binder/rust_binder_events.h"
+#endif
-- 
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