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| author | Yazen Ghannam <yazen.ghannam@amd.com> | 2026-09-03 10:43:25 -0500 |
|---|---|---|
| committer | Borislav Petkov (AMD) <bp@alien8.de> | 2026-09-10 18:05:43 -0700 |
| commit | 27600805e62f800bacf990354632eae4e487d34c (patch) | |
| tree | e8aec0ddfaa0bc264d79af632e3de3f1b75ae4c8 /arch/arm/lib/delay-loop.S | |
| download | linux-stable-27600805e62f800bacf990354632eae4e487d34c.tar.gz linux-stable-27600805e62f800bacf990354632eae4e487d34c.zip | |
x86/amd_node: Fix PCI device reference counting in amd_smn_init()grafted
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 <sashiko-bot@kernel.org>
Assisted-by: LLM
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Cc: <stable@kernel.org>
Link: https://patch.msgid.link/20260903154325.74343-1-yazen.ghannam@amd.com
Diffstat (limited to 'arch/arm/lib/delay-loop.S')
| -rw-r--r-- | arch/arm/lib/delay-loop.S | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/arch/arm/lib/delay-loop.S b/arch/arm/lib/delay-loop.S new file mode 100644 index 000000000..33b08ca1c --- /dev/null +++ b/arch/arm/lib/delay-loop.S @@ -0,0 +1,67 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * linux/arch/arm/lib/delay.S + * + * Copyright (C) 1995, 1996 Russell King + */ +#include <linux/linkage.h> +#include <linux/cfi_types.h> +#include <asm/assembler.h> +#include <asm/delay.h> + +#ifdef CONFIG_ARCH_RPC + .arch armv4 +#endif + + .text + +.LC0: .word loops_per_jiffy +.LC1: .word UDELAY_MULT + +/* + * loops = r0 * HZ * loops_per_jiffy / 1000000 + * + * r0 <= 2000 + * HZ <= 1000 + */ + +SYM_TYPED_FUNC_START(__loop_udelay) + ldr r2, .LC1 + mul r0, r2, r0 @ r0 = delay_us * UDELAY_MULT + b __loop_const_udelay +SYM_FUNC_END(__loop_udelay) + +SYM_TYPED_FUNC_START(__loop_const_udelay) @ 0 <= r0 <= 0xfffffaf0 + ldr r2, .LC0 + ldr r2, [r2] + umull r1, r0, r2, r0 @ r0-r1 = r0 * loops_per_jiffy + adds r1, r1, #0xffffffff @ rounding up ... + adcs r0, r0, r0 @ and right shift by 31 + reteq lr + b __loop_delay +SYM_FUNC_END(__loop_const_udelay) + + .align 3 + +@ Delay routine +SYM_TYPED_FUNC_START(__loop_delay) + subs r0, r0, #1 +#if 0 + retls lr + subs r0, r0, #1 + retls lr + subs r0, r0, #1 + retls lr + subs r0, r0, #1 + retls lr + subs r0, r0, #1 + retls lr + subs r0, r0, #1 + retls lr + subs r0, r0, #1 + retls lr + subs r0, r0, #1 +#endif + bhi __loop_delay + ret lr +SYM_FUNC_END(__loop_delay) |