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/crc/gen_crc32table.c | 89 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 89 insertions(+) create mode 100644 lib/crc/gen_crc32table.c (limited to 'lib/crc/gen_crc32table.c') diff --git a/lib/crc/gen_crc32table.c b/lib/crc/gen_crc32table.c new file mode 100644 index 000000000..9a7f31658 --- /dev/null +++ b/lib/crc/gen_crc32table.c @@ -0,0 +1,89 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include "../../include/linux/crc32poly.h" +#include "../../include/generated/autoconf.h" +#include + +static uint32_t crc32table_le[256]; +static uint32_t crc32table_be[256]; +static uint32_t crc32ctable_le[256]; + +/** + * crc32init_le() - allocate and initialize LE table data + * + * crc is the crc of the byte i; other entries are filled in based on the + * fact that crctable[i^j] = crctable[i] ^ crctable[j]. + * + */ +static void crc32init_le_generic(const uint32_t polynomial, uint32_t tab[256]) +{ + unsigned i, j; + uint32_t crc = 1; + + tab[0] = 0; + + for (i = 128; i; i >>= 1) { + crc = (crc >> 1) ^ ((crc & 1) ? polynomial : 0); + for (j = 0; j < 256; j += 2 * i) + tab[i + j] = crc ^ tab[j]; + } +} + +static void crc32init_le(void) +{ + crc32init_le_generic(CRC32_POLY_LE, crc32table_le); +} + +static void crc32cinit_le(void) +{ + crc32init_le_generic(CRC32C_POLY_LE, crc32ctable_le); +} + +/** + * crc32init_be() - allocate and initialize BE table data + */ +static void crc32init_be(void) +{ + unsigned i, j; + uint32_t crc = 0x80000000; + + crc32table_be[0] = 0; + + for (i = 1; i < 256; i <<= 1) { + crc = (crc << 1) ^ ((crc & 0x80000000) ? CRC32_POLY_BE : 0); + for (j = 0; j < i; j++) + crc32table_be[i + j] = crc ^ crc32table_be[j]; + } +} + +static void output_table(const uint32_t table[256]) +{ + int i; + + for (i = 0; i < 256; i += 4) { + printf("\t0x%08x, 0x%08x, 0x%08x, 0x%08x,\n", + table[i], table[i + 1], table[i + 2], table[i + 3]); + } +} + +int main(int argc, char** argv) +{ + printf("/* this file is generated - do not edit */\n\n"); + + crc32init_le(); + printf("static const u32 ____cacheline_aligned crc32table_le[256] = {\n"); + output_table(crc32table_le); + printf("};\n"); + + crc32init_be(); + printf("static const u32 ____cacheline_aligned crc32table_be[256] = {\n"); + output_table(crc32table_be); + printf("};\n"); + + crc32cinit_le(); + printf("static const u32 ____cacheline_aligned crc32ctable_le[256] = {\n"); + output_table(crc32ctable_le); + printf("};\n"); + + return 0; +} -- cgit v1.3.1