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/soc/microchip/mpfs-sys-controller.c | 282 ++++++++++++++++++++++++++++ 1 file changed, 282 insertions(+) create mode 100644 drivers/soc/microchip/mpfs-sys-controller.c (limited to 'drivers/soc/microchip/mpfs-sys-controller.c') diff --git a/drivers/soc/microchip/mpfs-sys-controller.c b/drivers/soc/microchip/mpfs-sys-controller.c new file mode 100644 index 000000000..0400a01b2 --- /dev/null +++ b/drivers/soc/microchip/mpfs-sys-controller.c @@ -0,0 +1,282 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Microchip PolarFire SoC (MPFS) system controller driver + * + * Copyright (c) 2020-2021 Microchip Corporation. All rights reserved. + * + * Author: Conor Dooley + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* + * This timeout must be long, as some services (example: image authentication) + * take significant time to complete + */ +#define MPFS_SYS_CTRL_TIMEOUT_MS 30000 + +static DEFINE_MUTEX(transaction_lock); + +struct mpfs_sys_controller { + struct mbox_client client; + struct mbox_chan *chan; + struct completion c; + struct mtd_info *flash; + struct kref consumers; +}; + +struct mpfs_syscon_config { + unsigned int nb_subdevs; + struct platform_device *subdevs; +}; + +int mpfs_blocking_transaction(struct mpfs_sys_controller *sys_controller, struct mpfs_mss_msg *msg) +{ + unsigned long timeout = msecs_to_jiffies(MPFS_SYS_CTRL_TIMEOUT_MS); + int ret; + + ret = mutex_lock_interruptible(&transaction_lock); + if (ret) + return ret; + + reinit_completion(&sys_controller->c); + + ret = mbox_send_message(sys_controller->chan, msg); + if (ret < 0) { + dev_warn(sys_controller->client.dev, "MPFS sys controller service timeout\n"); + goto out; + } + + /* + * Unfortunately, the system controller will only deliver an interrupt + * if a service succeeds. mbox_send_message() will block until the busy + * flag is gone. If the busy flag is gone but no interrupt has arrived + * to trigger the rx callback then the service can be deemed to have + * failed. + * The caller can then interrogate msg::response::resp_status to + * determine the cause of the failure. + * mbox_send_message() returns positive integers in the success path, so + * ret needs to be cleared if we do get an interrupt. + */ + if (!wait_for_completion_timeout(&sys_controller->c, timeout)) { + ret = -EBADMSG; + dev_warn(sys_controller->client.dev, + "MPFS sys controller service failed with status: %d\n", + msg->response->resp_status); + } else { + ret = 0; + } + +out: + mutex_unlock(&transaction_lock); + + return ret; +} +EXPORT_SYMBOL(mpfs_blocking_transaction); + +static void mpfs_sys_controller_rx_callback(struct mbox_client *client, void *msg) +{ + struct mpfs_sys_controller *sys_controller = + container_of(client, struct mpfs_sys_controller, client); + + complete(&sys_controller->c); +} + +static void mpfs_sys_controller_delete(struct kref *kref) +{ + struct mpfs_sys_controller *sys_controller = + container_of(kref, struct mpfs_sys_controller, consumers); + + mbox_free_channel(sys_controller->chan); + kfree(sys_controller); +} + +static void mpfs_sys_controller_put(void *data) +{ + struct mpfs_sys_controller *sys_controller = data; + + kref_put(&sys_controller->consumers, mpfs_sys_controller_delete); +} + +struct mtd_info *mpfs_sys_controller_get_flash(struct mpfs_sys_controller *mpfs_client) +{ + return mpfs_client->flash; +} +EXPORT_SYMBOL(mpfs_sys_controller_get_flash); + +static int mpfs_sys_controller_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct mpfs_sys_controller *sys_controller; + struct mpfs_syscon_config *of_data; + struct device_node *np; + int i, ret; + + sys_controller = kzalloc_obj(*sys_controller); + if (!sys_controller) + return -ENOMEM; + + np = of_parse_phandle(dev->of_node, "microchip,bitstream-flash", 0); + if (!np) + goto no_flash; + + sys_controller->flash = of_get_mtd_device_by_node(np); + of_node_put(np); + if (IS_ERR(sys_controller->flash)) { + ret = dev_err_probe(dev, PTR_ERR(sys_controller->flash), "Failed to get flash\n"); + goto out_free; + } + +no_flash: + sys_controller->client.dev = dev; + sys_controller->client.rx_callback = mpfs_sys_controller_rx_callback; + sys_controller->client.tx_block = 1U; + sys_controller->client.tx_tout = msecs_to_jiffies(MPFS_SYS_CTRL_TIMEOUT_MS); + + sys_controller->chan = mbox_request_channel(&sys_controller->client, 0); + if (IS_ERR(sys_controller->chan)) { + ret = dev_err_probe(dev, PTR_ERR(sys_controller->chan), + "Failed to get mbox channel\n"); + goto out_free; + } + + init_completion(&sys_controller->c); + kref_init(&sys_controller->consumers); + + platform_set_drvdata(pdev, sys_controller); + + of_data = (struct mpfs_syscon_config *) device_get_match_data(dev); + if (!of_data) { + ret = dev_err_probe(dev, -EINVAL, "Error getting match data\n"); + goto out_free_channel; + } + + for (i = 0; i < of_data->nb_subdevs; i++) { + of_data->subdevs[i].dev.parent = dev; + if (platform_device_register(&of_data->subdevs[i])) + dev_warn(dev, "Error registering sub device %s\n", + of_data->subdevs[i].name); + } + + dev_info(&pdev->dev, "Registered MPFS system controller\n"); + + return 0; + +out_free_channel: + mbox_free_channel(sys_controller->chan); +out_free: + kfree(sys_controller); + return ret; +} + +static void mpfs_sys_controller_remove(struct platform_device *pdev) +{ + struct mpfs_sys_controller *sys_controller = platform_get_drvdata(pdev); + + mpfs_sys_controller_put(sys_controller); +} + +static struct platform_device mpfs_subdevs[] = { + { + .name = "mpfs-rng", + .id = -1, + }, + { + .name = "mpfs-generic-service", + .id = -1, + }, + { + .name = "mpfs-auto-update", + .id = -1, + }, +}; + +static struct platform_device pic64gx_subdevs[] = { + { + .name = "mpfs-rng", + .id = -1, + }, + { + .name = "mpfs-generic-service", + .id = -1, + }, +}; + +static const struct mpfs_syscon_config mpfs_config = { + .nb_subdevs = ARRAY_SIZE(mpfs_subdevs), + .subdevs = mpfs_subdevs, +}; + +static const struct mpfs_syscon_config pic64gx_config = { + .nb_subdevs = ARRAY_SIZE(pic64gx_subdevs), + .subdevs = pic64gx_subdevs, +}; + +static const struct of_device_id mpfs_sys_controller_of_match[] = { + {.compatible = "microchip,mpfs-sys-controller", .data = &mpfs_config}, + {.compatible = "microchip,pic64gx-sys-controller", .data = &pic64gx_config}, + {}, +}; +MODULE_DEVICE_TABLE(of, mpfs_sys_controller_of_match); + +struct mpfs_sys_controller *mpfs_sys_controller_get(struct device *dev) +{ + const struct of_device_id *match; + struct mpfs_sys_controller *sys_controller; + int ret; + + if (!dev->parent) + goto err_no_device; + + match = of_match_node(mpfs_sys_controller_of_match, dev->parent->of_node); + of_node_put(dev->parent->of_node); + if (!match) + goto err_no_device; + + sys_controller = dev_get_drvdata(dev->parent); + if (!sys_controller) + goto err_bad_device; + + if (!kref_get_unless_zero(&sys_controller->consumers)) + goto err_bad_device; + + ret = devm_add_action_or_reset(dev, mpfs_sys_controller_put, sys_controller); + if (ret) + return ERR_PTR(ret); + + return sys_controller; + +err_no_device: + dev_dbg(dev, "Parent device was not an MPFS system controller\n"); + return ERR_PTR(-ENODEV); + +err_bad_device: + dev_dbg(dev, "MPFS system controller found but could not register as a sub device\n"); + return ERR_PTR(-EPROBE_DEFER); +} +EXPORT_SYMBOL(mpfs_sys_controller_get); + +static struct platform_driver mpfs_sys_controller_driver = { + .driver = { + .name = "mpfs-sys-controller", + .of_match_table = mpfs_sys_controller_of_match, + }, + .probe = mpfs_sys_controller_probe, + .remove = mpfs_sys_controller_remove, +}; +module_platform_driver(mpfs_sys_controller_driver); + +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Conor Dooley "); +MODULE_DESCRIPTION("MPFS system controller driver"); -- cgit v1.3.1