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 --- drivers/dma/amd/Kconfig | 42 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) create mode 100644 drivers/dma/amd/Kconfig (limited to 'drivers/dma/amd/Kconfig') diff --git a/drivers/dma/amd/Kconfig b/drivers/dma/amd/Kconfig new file mode 100644 index 000000000..00d874872 --- /dev/null +++ b/drivers/dma/amd/Kconfig @@ -0,0 +1,42 @@ +# SPDX-License-Identifier: GPL-2.0-only +# + +config AMD_AE4DMA + tristate "AMD AE4DMA Engine" + depends on (X86_64 || COMPILE_TEST) && PCI + depends on AMD_PTDMA + select DMA_ENGINE + select DMA_VIRTUAL_CHANNELS + help + Enable support for the AMD AE4DMA controller. This controller + provides DMA capabilities to perform high bandwidth memory to + memory and IO copy operations. It performs DMA transfer through + queue-based descriptor management. This DMA controller is intended + to be used with AMD Non-Transparent Bridge devices and not for + general purpose peripheral DMA. + +config AMD_PTDMA + tristate "AMD PassThru DMA Engine" + depends on X86_64 && PCI + select DMA_ENGINE + select DMA_VIRTUAL_CHANNELS + help + Enable support for the AMD PTDMA controller. This controller + provides DMA capabilities to perform high bandwidth memory to + memory and IO copy operations. It performs DMA transfer through + queue-based descriptor management. This DMA controller is intended + to be used with AMD Non-Transparent Bridge devices and not for + general purpose peripheral DMA. + +config AMD_QDMA + tristate "AMD Queue-based DMA" + depends on HAS_IOMEM + select DMA_ENGINE + select DMA_VIRTUAL_CHANNELS + select REGMAP_MMIO + help + Enable support for the AMD Queue-based DMA subsystem. The primary + mechanism to transfer data using the QDMA is for the QDMA engine to + operate on instructions (descriptors) provided by the host operating + system. Using the descriptors, the QDMA can move data in either the + Host to Card (H2C) direction or the Card to Host (C2H) direction. -- cgit v1.3.1