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 --- arch/xtensa/lib/modsi3.S | 88 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 88 insertions(+) create mode 100644 arch/xtensa/lib/modsi3.S (limited to 'arch/xtensa/lib/modsi3.S') diff --git a/arch/xtensa/lib/modsi3.S b/arch/xtensa/lib/modsi3.S new file mode 100644 index 000000000..c5f4295c6 --- /dev/null +++ b/arch/xtensa/lib/modsi3.S @@ -0,0 +1,88 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later WITH GCC-exception-2.0 */ +#include +#include +#include + +ENTRY(__modsi3) + + abi_entry_default +#if XCHAL_HAVE_DIV32 + rems a2, a2, a3 +#else + mov a7, a2 /* save original (signed) dividend */ + do_abs a2, a2, a4 /* udividend = abs (dividend) */ + do_abs a3, a3, a4 /* udivisor = abs (divisor) */ + bltui a3, 2, .Lle_one /* check if udivisor <= 1 */ + do_nsau a5, a2, a6, a8 /* udividend_shift = nsau (udividend) */ + do_nsau a4, a3, a6, a8 /* udivisor_shift = nsau (udivisor) */ + bgeu a5, a4, .Lspecial + + sub a4, a4, a5 /* count = udivisor_shift - udividend_shift */ + ssl a4 + sll a3, a3 /* udivisor <<= count */ + + /* test-subtract-and-shift loop */ +#if XCHAL_HAVE_LOOPS + loopnez a4, .Lloopend +#endif /* XCHAL_HAVE_LOOPS */ +.Lloop: + bltu a2, a3, .Lzerobit + sub a2, a2, a3 +.Lzerobit: + srli a3, a3, 1 +#if !XCHAL_HAVE_LOOPS + addi a4, a4, -1 + bnez a4, .Lloop +#endif /* !XCHAL_HAVE_LOOPS */ +.Lloopend: + +.Lspecial: + bltu a2, a3, .Lreturn + sub a2, a2, a3 /* subtract again if udividend >= udivisor */ +.Lreturn: + bgez a7, .Lpositive + neg a2, a2 /* if (dividend < 0), return -udividend */ +.Lpositive: + abi_ret_default + +.Lle_one: + bnez a3, .Lreturn0 + + /* Divide by zero: Use an illegal instruction to force an exception. + The subsequent "DIV0" string can be recognized by the exception + handler to identify the real cause of the exception. */ + ill + .ascii "DIV0" + +.Lreturn0: + movi a2, 0 +#endif /* XCHAL_HAVE_DIV32 */ + abi_ret_default + +ENDPROC(__modsi3) +EXPORT_SYMBOL(__modsi3) + +#if !XCHAL_HAVE_NSA + .section .rodata + .align 4 + .global __nsau_data + .type __nsau_data, @object +__nsau_data: + .byte 8, 7, 6, 6, 5, 5, 5, 5, 4, 4, 4, 4, 4, 4, 4, 4 + .byte 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3 + .byte 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2 + .byte 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2 + .byte 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 + .byte 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 + .byte 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 + .byte 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 + .byte 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 + .byte 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 + .byte 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 + .byte 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 + .byte 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 + .byte 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 + .byte 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 + .byte 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 + .size __nsau_data, . - __nsau_data +#endif /* !XCHAL_HAVE_NSA */ -- cgit v1.3.1