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/net/libeth/tx.h | 159 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 159 insertions(+) create mode 100644 include/net/libeth/tx.h (limited to 'include/net/libeth/tx.h') diff --git a/include/net/libeth/tx.h b/include/net/libeth/tx.h new file mode 100644 index 000000000..c3db5c6f1 --- /dev/null +++ b/include/net/libeth/tx.h @@ -0,0 +1,159 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* Copyright (C) 2024-2025 Intel Corporation */ + +#ifndef __LIBETH_TX_H +#define __LIBETH_TX_H + +#include + +#include + +/* Tx buffer completion */ + +/** + * enum libeth_sqe_type - type of &libeth_sqe to act on Tx completion + * @LIBETH_SQE_EMPTY: unused/empty OR XDP_TX/XSk frame, no action required + * @LIBETH_SQE_CTX: context descriptor with empty SQE, no action required + * @LIBETH_SQE_SLAB: kmalloc-allocated buffer, unmap and kfree() + * @LIBETH_SQE_FRAG: mapped skb frag, only unmap DMA + * @LIBETH_SQE_SKB: &sk_buff, unmap and napi_consume_skb(), update stats + * @__LIBETH_SQE_XDP_START: separator between skb and XDP types + * @LIBETH_SQE_XDP_TX: &skb_shared_info, libeth_xdp_return_buff_bulk(), stats + * @LIBETH_SQE_XDP_XMIT: &xdp_frame, unmap and xdp_return_frame_bulk(), stats + * @LIBETH_SQE_XDP_XMIT_FRAG: &xdp_frame frag, only unmap DMA + * @LIBETH_SQE_XSK_TX: &libeth_xdp_buff on XSk queue, xsk_buff_free(), stats + * @LIBETH_SQE_XSK_TX_FRAG: &libeth_xdp_buff frag on XSk queue, xsk_buff_free() + */ +enum libeth_sqe_type { + LIBETH_SQE_EMPTY = 0U, + LIBETH_SQE_CTX, + LIBETH_SQE_SLAB, + LIBETH_SQE_FRAG, + LIBETH_SQE_SKB, + + __LIBETH_SQE_XDP_START, + LIBETH_SQE_XDP_TX = __LIBETH_SQE_XDP_START, + LIBETH_SQE_XDP_XMIT, + LIBETH_SQE_XDP_XMIT_FRAG, + LIBETH_SQE_XSK_TX, + LIBETH_SQE_XSK_TX_FRAG, +}; + +/** + * struct libeth_sqe - represents a Send Queue Element / Tx buffer + * @type: type of the buffer, see the enum above + * @rs_idx: index of the last buffer from the batch this one was sent in + * @raw: slab buffer to free via kfree() + * @skb: &sk_buff to consume + * @sinfo: skb shared info of an XDP_TX frame + * @xdpf: XDP frame from ::ndo_xdp_xmit() + * @xsk: XSk Rx frame from XDP_TX action + * @dma: DMA address to unmap + * @len: length of the mapped region to unmap + * @nr_frags: number of frags in the frame this buffer belongs to + * @packets: number of physical packets sent for this frame + * @bytes: number of physical bytes sent for this frame + * @priv: driver-private scratchpad + */ +struct libeth_sqe { + enum libeth_sqe_type type:32; + u32 rs_idx; + + union { + void *raw; + struct sk_buff *skb; + struct skb_shared_info *sinfo; + struct xdp_frame *xdpf; + struct libeth_xdp_buff *xsk; + }; + + DEFINE_DMA_UNMAP_ADDR(dma); + DEFINE_DMA_UNMAP_LEN(len); + + u32 nr_frags; + u32 packets; + u32 bytes; + + unsigned long priv; +} __aligned_largest; + +/** + * LIBETH_SQE_CHECK_PRIV - check the driver's private SQE data + * @p: type or name of the object the driver wants to fit into &libeth_sqe + * + * Make sure the driver's private data fits into libeth_sqe::priv. To be used + * right after its declaration. + */ +#define LIBETH_SQE_CHECK_PRIV(p) \ + static_assert(sizeof(p) <= sizeof_field(struct libeth_sqe, priv)) + +/** + * struct libeth_cq_pp - completion queue poll params + * @dev: &device to perform DMA unmapping + * @bq: XDP frame bulk to combine return operations + * @ss: onstack NAPI stats to fill + * @xss: onstack XDPSQ NAPI stats to fill + * @xdp_tx: number of XDP-not-XSk frames processed + * @napi: whether it's called from the NAPI context + * + * libeth uses this structure to access objects needed for performing full + * Tx complete operation without passing lots of arguments and change the + * prototypes each time a new one is added. + */ +struct libeth_cq_pp { + struct device *dev; + struct xdp_frame_bulk *bq; + + union { + struct libeth_sq_napi_stats *ss; + struct libeth_xdpsq_napi_stats *xss; + }; + u32 xdp_tx; + + bool napi; +}; + +/** + * libeth_tx_complete - perform Tx completion for one SQE + * @sqe: SQE to complete + * @cp: poll params + * + * Do Tx complete for all the types of buffers, incl. freeing, unmapping, + * updating the stats etc. + */ +static inline void libeth_tx_complete(struct libeth_sqe *sqe, + const struct libeth_cq_pp *cp) +{ + switch (sqe->type) { + case LIBETH_SQE_EMPTY: + return; + case LIBETH_SQE_SKB: + case LIBETH_SQE_FRAG: + case LIBETH_SQE_SLAB: + dma_unmap_page(cp->dev, dma_unmap_addr(sqe, dma), + dma_unmap_len(sqe, len), DMA_TO_DEVICE); + break; + default: + break; + } + + switch (sqe->type) { + case LIBETH_SQE_SKB: + cp->ss->packets += sqe->packets; + cp->ss->bytes += sqe->bytes; + + napi_consume_skb(sqe->skb, cp->napi); + break; + case LIBETH_SQE_SLAB: + kfree(sqe->raw); + break; + default: + break; + } + + sqe->type = LIBETH_SQE_EMPTY; +} + +void libeth_tx_complete_any(struct libeth_sqe *sqe, struct libeth_cq_pp *cp); + +#endif /* __LIBETH_TX_H */ -- cgit v1.3.1