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 --- drivers/cpuidle/poll_state.c | 66 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 66 insertions(+) create mode 100644 drivers/cpuidle/poll_state.c (limited to 'drivers/cpuidle/poll_state.c') diff --git a/drivers/cpuidle/poll_state.c b/drivers/cpuidle/poll_state.c new file mode 100644 index 000000000..c7524e4c5 --- /dev/null +++ b/drivers/cpuidle/poll_state.c @@ -0,0 +1,66 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * poll_state.c - Polling idle state + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#define POLL_IDLE_RELAX_COUNT 200 + +static int __cpuidle poll_idle(struct cpuidle_device *dev, + struct cpuidle_driver *drv, int index) +{ + u64 time_start; + + time_start = local_clock_noinstr(); + + dev->poll_time_limit = false; + + raw_local_irq_enable(); + if (!current_set_polling_and_test()) { + unsigned int loop_count = 0; + u64 limit; + + limit = cpuidle_poll_time(drv, dev); + + while (!need_resched()) { + cpu_relax(); + if (loop_count++ < POLL_IDLE_RELAX_COUNT) + continue; + + loop_count = 0; + if (local_clock_noinstr() - time_start > limit) { + dev->poll_time_limit = true; + break; + } + } + } + raw_local_irq_disable(); + + current_clr_polling(); + + return index; +} + +void cpuidle_poll_state_init(struct cpuidle_driver *drv) +{ + struct cpuidle_state *state = &drv->states[0]; + + snprintf(state->name, CPUIDLE_NAME_LEN, "POLL"); + snprintf(state->desc, CPUIDLE_DESC_LEN, "CPUIDLE CORE POLL IDLE"); + state->exit_latency = 0; + state->target_residency = 0; + state->exit_latency_ns = 0; + state->target_residency_ns = 0; + state->power_usage = -1; + state->enter = poll_idle; + state->flags = CPUIDLE_FLAG_POLLING; +} +EXPORT_SYMBOL_GPL(cpuidle_poll_state_init); -- cgit v1.3.1