From 27600805e62f800bacf990354632eae4e487d34c Mon Sep 17 00:00:00 2001 From: Yazen Ghannam 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 Assisted-by: LLM Signed-off-by: Yazen Ghannam Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Mario Limonciello (AMD) Cc: Link: https://patch.msgid.link/20260903154325.74343-1-yazen.ghannam@amd.com --- include/acpi/pcc.h | 49 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 49 insertions(+) create mode 100644 include/acpi/pcc.h (limited to 'include/acpi/pcc.h') diff --git a/include/acpi/pcc.h b/include/acpi/pcc.h new file mode 100644 index 000000000..840bfc95b --- /dev/null +++ b/include/acpi/pcc.h @@ -0,0 +1,49 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * PCC (Platform Communications Channel) methods + */ + +#ifndef _PCC_H +#define _PCC_H + +#include +#include + +struct pcc_mbox_chan { + struct mbox_chan *mchan; + u64 shmem_base_addr; + void __iomem *shmem; + u64 shmem_size; + u32 latency; + u32 max_access_rate; + u16 min_turnaround_time; +}; + +/* Generic Communications Channel Shared Memory Region */ +#define PCC_SIGNATURE 0x50434300 +/* Generic Communications Channel Command Field */ +#define PCC_CMD_GENERATE_DB_INTR BIT(15) +/* Generic Communications Channel Status Field */ +#define PCC_STATUS_CMD_COMPLETE BIT(0) +#define PCC_STATUS_SCI_DOORBELL BIT(1) +#define PCC_STATUS_ERROR BIT(2) +#define PCC_STATUS_PLATFORM_NOTIFY BIT(3) +/* Initiator Responder Communications Channel Flags */ +#define PCC_CMD_COMPLETION_NOTIFY BIT(0) + +#define MAX_PCC_SUBSPACES 256 + +#ifdef CONFIG_PCC +extern struct pcc_mbox_chan * +pcc_mbox_request_channel(struct mbox_client *cl, int subspace_id); +extern void pcc_mbox_free_channel(struct pcc_mbox_chan *chan); +#else +static inline struct pcc_mbox_chan * +pcc_mbox_request_channel(struct mbox_client *cl, int subspace_id) +{ + return ERR_PTR(-ENODEV); +} +static inline void pcc_mbox_free_channel(struct pcc_mbox_chan *chan) { } +#endif + +#endif /* _PCC_H */ -- cgit v1.3.1