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 --- lib/crypto/powerpc/sha256.h | 58 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 58 insertions(+) create mode 100644 lib/crypto/powerpc/sha256.h (limited to 'lib/crypto/powerpc/sha256.h') diff --git a/lib/crypto/powerpc/sha256.h b/lib/crypto/powerpc/sha256.h new file mode 100644 index 000000000..50d355441 --- /dev/null +++ b/lib/crypto/powerpc/sha256.h @@ -0,0 +1,58 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * SHA-256 Secure Hash Algorithm, SPE optimized + * + * Based on generic implementation. The assembler module takes care + * about the SPE registers so it can run from interrupt context. + * + * Copyright (c) 2015 Markus Stockhausen + */ + +#include +#include + +/* + * MAX_BYTES defines the number of bytes that are allowed to be processed + * between preempt_disable() and preempt_enable(). SHA256 takes ~2,000 + * operations per 64 bytes. e500 cores can issue two arithmetic instructions + * per clock cycle using one 32/64 bit unit (SU1) and one 32 bit unit (SU2). + * Thus 1KB of input data will need an estimated maximum of 18,000 cycles. + * Headroom for cache misses included. Even with the low end model clocked + * at 667 MHz this equals to a critical time window of less than 27us. + * + */ +#define MAX_BYTES 1024 + +extern void ppc_spe_sha256_transform(struct sha256_block_state *state, + const u8 *src, u32 blocks); + +static void spe_begin(void) +{ + /* We just start SPE operations and will save SPE registers later. */ + preempt_disable(); + enable_kernel_spe(); +} + +static void spe_end(void) +{ + disable_kernel_spe(); + /* reenable preemption */ + preempt_enable(); +} + +static void sha256_blocks(struct sha256_block_state *state, + const u8 *data, size_t nblocks) +{ + do { + /* cut input data into smaller blocks */ + u32 unit = min_t(size_t, nblocks, + MAX_BYTES / SHA256_BLOCK_SIZE); + + spe_begin(); + ppc_spe_sha256_transform(state, data, unit); + spe_end(); + + data += unit * SHA256_BLOCK_SIZE; + nblocks -= unit; + } while (nblocks); +} -- cgit v1.3.1