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/dhry_run.c | 87 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 87 insertions(+) create mode 100644 lib/dhry_run.c (limited to 'lib/dhry_run.c') diff --git a/lib/dhry_run.c b/lib/dhry_run.c new file mode 100644 index 000000000..4a6d05ce4 --- /dev/null +++ b/lib/dhry_run.c @@ -0,0 +1,87 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Dhrystone benchmark test module + * + * Copyright (C) 2022 Glider bv + */ + +#include "dhry.h" + +#include +#include +#include +#include + +#define DHRY_VAX 1757 + +static int dhry_run_set(const char *val, const struct kernel_param *kp); +static const struct kernel_param_ops run_ops = { + .flags = KERNEL_PARAM_OPS_FL_NOARG, + .set = dhry_run_set, +}; +static bool dhry_run; +module_param_cb(run, &run_ops, &dhry_run, 0200); +MODULE_PARM_DESC(run, "Run the test (default: false)"); + +static int iterations = -1; +module_param(iterations, int, 0644); +MODULE_PARM_DESC(iterations, + "Number of iterations through the benchmark (default: auto)"); + +static void dhry_benchmark(void) +{ + unsigned int cpu = get_cpu(); + int i, n; + + if (iterations > 0) { + n = dhry(iterations); + goto report; + } + + for (i = DHRY_VAX; i > 0; i <<= 1) { + n = dhry(i); + if (n != -EAGAIN) + break; + } + +report: + put_cpu(); + if (n >= 0) + pr_info("CPU%u: Dhrystones per Second: %d (%d DMIPS)\n", cpu, + n, n / DHRY_VAX); + else if (n == -EAGAIN) + pr_err("Please increase the number of iterations\n"); + else + pr_err("Dhrystone benchmark failed error %pe\n", ERR_PTR(n)); +} + +static int dhry_run_set(const char *val, const struct kernel_param *kp) +{ + int ret; + + if (val) { + ret = param_set_bool(val, kp); + if (ret) + return ret; + } else { + dhry_run = true; + } + + if (dhry_run && system_state == SYSTEM_RUNNING) + dhry_benchmark(); + + return 0; +} + +static int __init dhry_init(void) +{ + if (dhry_run) + dhry_benchmark(); + + return 0; +} +module_init(dhry_init); + +MODULE_AUTHOR("Geert Uytterhoeven "); +MODULE_DESCRIPTION("Dhrystone benchmark test module"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1