From 5febf432df1cfa5b25d99b54c32103fafbdd0eb9 Mon Sep 17 00:00:00 2001 From: Miguel Ojeda Date: Sun, 16 Aug 2026 15:32:33 +0200 Subject: kbuild: rust: keep Rust objects out of Clang LTO with inline helpers Under `CONFIG_LTO_CLANG` + `CONFIG_RUST_INLINE_HELPERS`, one may hit `objtool` errors such as: vmlinux.o: error: objtool: _R..._3Gsp4boot+0xd6a: can't find jump dest instruction at .text._R..._3Gsp4boot+0x1dfd The reason is that in such builds, the Clang invocation that compiles the combined Rust plus helpers bitcode emits LLVM bitcode (again) -- the final code generation happens in the linker's LTO step, which the `-mllvm` trap options passed to Clang do not reach. This, in turn, means that unreachable traps are missing, and the impossible paths do not merely fallthrough to the next symbol, but past the end of their own section, since LTO builds place each function in its own section. Thus filter `CC_FLAGS_LTO` out of the Clang invocation, so that it always emits machine code directly, with the traps in place. Assisted-by: LLM Cc: Gary Guo Cc: Boqun Feng Cc: Alice Ryhl Cc: Matthew Maurer Cc: Josh Poimboeuf Cc: Peter Zijlstra Cc: stable@vger.kernel.org Fixes: 3a2486cc1da5 ("kbuild: rust: provide an option to inline C helpers into Rust") Acked-by: Gary Guo Link: https://patch.msgid.link/20260816133233.197500-2-ojeda@kernel.org Signed-off-by: Miguel Ojeda --- drivers/gpu/host1x/intr.c | 159 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 159 insertions(+) create mode 100644 drivers/gpu/host1x/intr.c (limited to 'drivers/gpu/host1x/intr.c') diff --git a/drivers/gpu/host1x/intr.c b/drivers/gpu/host1x/intr.c new file mode 100644 index 000000000..723297250 --- /dev/null +++ b/drivers/gpu/host1x/intr.c @@ -0,0 +1,159 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Tegra host1x Interrupt Management + * + * Copyright (c) 2010-2021, NVIDIA Corporation. + */ + +#include +#include +#include "dev.h" +#include "fence.h" +#include "intr.h" + +static void host1x_intr_add_fence_to_list(struct host1x_fence_list *list, + struct host1x_syncpt_fence *fence) +{ + struct host1x_syncpt_fence *fence_in_list; + + list_for_each_entry_reverse(fence_in_list, &list->list, list) { + if ((s32)(fence_in_list->threshold - fence->threshold) <= 0) { + /* Fence in list is before us, we can insert here */ + list_add(&fence->list, &fence_in_list->list); + return; + } + } + + /* Add as first in list */ + list_add(&fence->list, &list->list); +} + +static void host1x_intr_update_hw_state(struct host1x *host, struct host1x_syncpt *sp) +{ + struct host1x_syncpt_fence *fence; + + if (!list_empty(&sp->fences.list)) { + fence = list_first_entry(&sp->fences.list, struct host1x_syncpt_fence, list); + + host1x_hw_intr_set_syncpt_threshold(host, sp->id, fence->threshold); + host1x_hw_intr_enable_syncpt_intr(host, sp->id); + } else { + host1x_hw_intr_disable_syncpt_intr(host, sp->id); + } +} + +void host1x_intr_add_fence_locked(struct host1x *host, struct host1x_syncpt_fence *fence) +{ + struct host1x_fence_list *fence_list = &fence->sp->fences; + + INIT_LIST_HEAD(&fence->list); + + host1x_intr_add_fence_to_list(fence_list, fence); + host1x_intr_update_hw_state(host, fence->sp); +} + +bool host1x_intr_remove_fence(struct host1x *host, struct host1x_syncpt_fence *fence) +{ + struct host1x_fence_list *fence_list = &fence->sp->fences; + unsigned long irqflags; + + spin_lock_irqsave(&fence_list->lock, irqflags); + + if (list_empty(&fence->list)) { + spin_unlock_irqrestore(&fence_list->lock, irqflags); + return false; + } + + list_del_init(&fence->list); + host1x_intr_update_hw_state(host, fence->sp); + + spin_unlock_irqrestore(&fence_list->lock, irqflags); + + return true; +} + +void host1x_intr_handle_interrupt(struct host1x *host, unsigned int id) +{ + struct host1x_syncpt *sp = &host->syncpt[id]; + struct host1x_syncpt_fence *fence, *tmp; + unsigned int value; + + value = host1x_syncpt_load(sp); + + spin_lock(&sp->fences.lock); + + list_for_each_entry_safe(fence, tmp, &sp->fences.list, list) { + if (((value - fence->threshold) & 0x80000000U) != 0U) { + /* Fence is not yet expired, we are done */ + break; + } + + list_del_init(&fence->list); + host1x_fence_signal(fence); + } + + /* + * Re-enable interrupt if necessary. The ISR already disabled the interrupt, + * so if no fences remain, no update is needed. + */ + if (!list_empty(&sp->fences.list)) + host1x_intr_update_hw_state(host, sp); + + spin_unlock(&sp->fences.lock); +} + +int host1x_intr_init(struct host1x *host) +{ + struct host1x_intr_irq_data *irq_data; + unsigned int id; + int i, err; + + for (id = 0; id < host1x_syncpt_nb_pts(host); ++id) { + struct host1x_syncpt *syncpt = &host->syncpt[id]; + + spin_lock_init(&syncpt->fences.lock); + INIT_LIST_HEAD(&syncpt->fences.list); + } + + irq_data = devm_kcalloc(host->dev, host->num_syncpt_irqs, sizeof(irq_data[0]), GFP_KERNEL); + if (!irq_data) + return -ENOMEM; + + host1x_hw_intr_disable_all_syncpt_intrs(host); + + for (i = 0; i < host->num_syncpt_irqs; i++) { + irq_data[i].host = host; + irq_data[i].offset = i; + + err = devm_request_irq(host->dev, host->syncpt_irqs[i], + host->intr_op->isr, IRQF_SHARED, + "host1x_syncpt", &irq_data[i]); + if (err < 0) + return err; + } + + return 0; +} + +void host1x_intr_deinit(struct host1x *host) +{ +} + +void host1x_intr_start(struct host1x *host) +{ + u32 hz = clk_get_rate(host->clk); + int err; + + mutex_lock(&host->intr_mutex); + err = host1x_hw_intr_init_host_sync(host, DIV_ROUND_UP(hz, 1000000)); + if (err) { + mutex_unlock(&host->intr_mutex); + return; + } + mutex_unlock(&host->intr_mutex); +} + +void host1x_intr_stop(struct host1x *host) +{ + host1x_hw_intr_disable_all_syncpt_intrs(host); +} -- cgit v1.3.1