From 034dd340b08be1f2f0477ad16131d609f9dbd53c Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 30 Aug 2026 09:22:00 -0700 Subject: Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Fix error output of boot instance creation failure Currently if a boot instance creation fails, instead of printing out the name of the instance that failed, it prints "(null)". That is because it prints "cur_str" that had already been processed by strsep(). Print the saved name instead. While at it, print the error code of the failure. - Fix use-after-free for same named historgrams Histograms can be named so that they can be used in multiple events. But if the named histogram has a variable attached, the second event that uses the named histogram which duplicates it and needs to free the original after duplication leaves the old variable in place and still visible. If another histogram uses than variable, it will use the stale one which will try to reference the freed duplicate histogram and crash the kernel. Free the duplicate variables along with the duplicated histogram data. - Check return value of kthread_run() in event self test The events self tests uses a kthread for testing but does not check if it succeeded in creating a kthread. If the kthread creation were to fail, the code will still try to call kthread_stop() on the error returned. - Fix race between reading trace_pipe and updating subbuffer size If a user is reading the trace_pipe file at the same time they update the ring buffer sub-buffer size, can cause the trace_pipe read to read stale data. Add trace_access_lock() around updating the ring buffer sub-buffer size. - Fix eventfs_inode on failure path in creation of the events directory In the creation of the "events" directory, if after allocating the eventfs_inode a failure is detected, it calls cleanup_ei() which calls free_ei(). The free_ei() will test if eventfs_inode being freed has no children. It is a bug if it does. But on the failure case of the creation of the "events" directory, the children lists have not yet been initialized and the free will trigger a warning because list_empty() on an uninitialized list returns false. Move the initialization into init_ei() where it makes more sense and makes sure that a created eventfs_inode has its lists initialized upon creation. - Check return value of kthread_run() in ftrace direct sample code The sample code that shows how to use the ftrace direct calls does not test the return of kthread_run() to see if it succeeds. Return a failure if the kthread_run() doesn't succeed. - Clear user events state on fork in case of alloc failure On fork, the child gets a pointer to the parent's user events state. It makes a copy of it then updates the child's pointer to it. But if the allocation fails, the duplication function leaves the child with a pointer to its parent's descriptor. When the child cleans up its data, it will free the parent's descriptor while the parent is still using it. In the duplication function, set the child's user_event_mm to NULL before testing if the allocation succeeded, and when it exits it will not free the parent's descriptor. - Fix retry exhaustion in simple ring buffer reader swap simple_ring_buffer_swap_reader_page() starts with retry set to 8 and post-decrements it only after a failed link replacement. On the final attempt, a successful replacement leaves retry at zero, while a failed replacement leaves it at -1. But the check for success expects the retry value to be non-zero and exits with an error on zero. This is the opposite result. Fix it. - Fail nicely when the remote swap_reader_page() returns an error Currently, if the swap_reader_page() of a remote buffer fails, it triggers a WARN_ON_ONCE() and continues normally. Instead, have it exit with an error and a pr_warn() print instead of a full WARNING. * tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: ring-buffer: Stop remote reader update when page swap fails tracing: Fix retry exhaustion in simple ring buffer reader swap tracing/user_events: Clear copied tracing state before fork duplication samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify eventfs: Initialize ei->children and ei->list in init_ei() tracing: Fix use-after-free in trace_pipe read on sub-buffer order change tracing: Fix crash passing ERR_PTR to kthread_stop() tracing: Fix use-after-free with same-name named triggers tracing: Fix logged instance name on creation failure --- drivers/mfd/macsmc.c | 506 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 506 insertions(+) create mode 100644 drivers/mfd/macsmc.c (limited to 'drivers/mfd/macsmc.c') diff --git a/drivers/mfd/macsmc.c b/drivers/mfd/macsmc.c new file mode 100644 index 000000000..514cba7dc --- /dev/null +++ b/drivers/mfd/macsmc.c @@ -0,0 +1,506 @@ +// SPDX-License-Identifier: GPL-2.0-only OR MIT +/* + * Apple SMC (System Management Controller) MFD driver + * + * Copyright The Asahi Linux Contributors + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define SMC_ENDPOINT 0x20 + +/* We don't actually know the true size here but this seem reasonable */ +#define SMC_SHMEM_SIZE 0x1000 +#define SMC_MAX_SIZE 255 + +#define SMC_MSG_READ_KEY 0x10 +#define SMC_MSG_WRITE_KEY 0x11 +#define SMC_MSG_GET_KEY_BY_INDEX 0x12 +#define SMC_MSG_GET_KEY_INFO 0x13 +#define SMC_MSG_INITIALIZE 0x17 +#define SMC_MSG_NOTIFICATION 0x18 +#define SMC_MSG_RW_KEY 0x20 + +#define SMC_DATA GENMASK_ULL(63, 32) +#define SMC_WSIZE GENMASK_ULL(31, 24) +#define SMC_SIZE GENMASK_ULL(23, 16) +#define SMC_ID GENMASK_ULL(15, 12) +#define SMC_MSG GENMASK_ULL(7, 0) +#define SMC_RESULT SMC_MSG + +#define SMC_TIMEOUT_MS 500 + +static const struct mfd_cell apple_smc_devs[] = { + MFD_CELL_NAME("macsmc-input"), + MFD_CELL_NAME("macsmc-power"), + MFD_CELL_OF("macsmc-gpio", NULL, NULL, 0, 0, "apple,smc-gpio"), + MFD_CELL_OF("macsmc-hwmon", NULL, NULL, 0, 0, "apple,smc-hwmon"), + MFD_CELL_OF("macsmc-reboot", NULL, NULL, 0, 0, "apple,smc-reboot"), + MFD_CELL_OF("macsmc-rtc", NULL, NULL, 0, 0, "apple,smc-rtc"), +}; + +static int apple_smc_cmd_locked(struct apple_smc *smc, u64 cmd, u64 arg, + u64 size, u64 wsize, u32 *ret_data) +{ + u8 result; + int ret; + u64 msg; + + lockdep_assert_held(&smc->mutex); + + if (smc->boot_stage != APPLE_SMC_INITIALIZED) + return -EIO; + if (smc->atomic_mode) + return -EIO; + + reinit_completion(&smc->cmd_done); + + smc->msg_id = (smc->msg_id + 1) & 0xf; + msg = (FIELD_PREP(SMC_MSG, cmd) | + FIELD_PREP(SMC_SIZE, size) | + FIELD_PREP(SMC_WSIZE, wsize) | + FIELD_PREP(SMC_ID, smc->msg_id) | + FIELD_PREP(SMC_DATA, arg)); + + ret = apple_rtkit_send_message(smc->rtk, SMC_ENDPOINT, msg, NULL, false); + if (ret) { + dev_err(smc->dev, "Failed to send command\n"); + return ret; + } + + if (wait_for_completion_timeout(&smc->cmd_done, msecs_to_jiffies(SMC_TIMEOUT_MS)) <= 0) { + dev_err(smc->dev, "Command timed out (%llx)", msg); + return -ETIMEDOUT; + } + + if (FIELD_GET(SMC_ID, smc->cmd_ret) != smc->msg_id) { + dev_err(smc->dev, "Command sequence mismatch (expected %d, got %d)\n", + smc->msg_id, (unsigned int)FIELD_GET(SMC_ID, smc->cmd_ret)); + return -EIO; + } + + result = FIELD_GET(SMC_RESULT, smc->cmd_ret); + if (result) + return -EIO; + + if (ret_data) + *ret_data = FIELD_GET(SMC_DATA, smc->cmd_ret); + + return FIELD_GET(SMC_SIZE, smc->cmd_ret); +} + +static int apple_smc_cmd(struct apple_smc *smc, u64 cmd, u64 arg, + u64 size, u64 wsize, u32 *ret_data) +{ + guard(mutex)(&smc->mutex); + + return apple_smc_cmd_locked(smc, cmd, arg, size, wsize, ret_data); +} + +static int apple_smc_rw_locked(struct apple_smc *smc, smc_key key, + const void *wbuf, size_t wsize, + void *rbuf, size_t rsize) +{ + u64 smc_size, smc_wsize; + u32 rdata; + int ret; + u64 cmd; + + lockdep_assert_held(&smc->mutex); + + if (rsize > SMC_MAX_SIZE) + return -EINVAL; + if (wsize > SMC_MAX_SIZE) + return -EINVAL; + + if (rsize && wsize) { + cmd = SMC_MSG_RW_KEY; + memcpy_toio(smc->shmem.iomem, wbuf, wsize); + smc_size = rsize; + smc_wsize = wsize; + } else if (wsize && !rsize) { + cmd = SMC_MSG_WRITE_KEY; + memcpy_toio(smc->shmem.iomem, wbuf, wsize); + /* + * Setting size to the length we want to write and wsize to 0 + * looks silly but that's how the SMC protocol works ¯\_(ツ)_/¯ + */ + smc_size = wsize; + smc_wsize = 0; + } else if (!wsize && rsize) { + cmd = SMC_MSG_READ_KEY; + smc_size = rsize; + smc_wsize = 0; + } else { + return -EINVAL; + } + + ret = apple_smc_cmd_locked(smc, cmd, key, smc_size, smc_wsize, &rdata); + if (ret < 0) + return ret; + + if (rsize) { + /* + * Small data <= 4 bytes is returned as part of the reply + * message which is sent over the mailbox FIFO. Everything + * bigger has to be copied from SRAM which is mapped as + * Device memory. + */ + if (rsize <= 4) + memcpy(rbuf, &rdata, rsize); + else + memcpy_fromio(rbuf, smc->shmem.iomem, rsize); + } + + return ret; +} + +int apple_smc_read(struct apple_smc *smc, smc_key key, void *buf, size_t size) +{ + guard(mutex)(&smc->mutex); + + return apple_smc_rw_locked(smc, key, NULL, 0, buf, size); +} +EXPORT_SYMBOL(apple_smc_read); + +int apple_smc_write(struct apple_smc *smc, smc_key key, const void *buf, size_t size) +{ + guard(mutex)(&smc->mutex); + + return apple_smc_rw_locked(smc, key, buf, size, NULL, 0); +} +EXPORT_SYMBOL(apple_smc_write); + +int apple_smc_rw(struct apple_smc *smc, smc_key key, const void *wbuf, size_t wsize, + void *rbuf, size_t rsize) +{ + guard(mutex)(&smc->mutex); + + return apple_smc_rw_locked(smc, key, wbuf, wsize, rbuf, rsize); +} +EXPORT_SYMBOL(apple_smc_rw); + +int apple_smc_get_key_by_index(struct apple_smc *smc, int index, smc_key *key) +{ + int ret; + + ret = apple_smc_cmd(smc, SMC_MSG_GET_KEY_BY_INDEX, index, 0, 0, key); + + *key = swab32(*key); + return ret; +} +EXPORT_SYMBOL(apple_smc_get_key_by_index); + +int apple_smc_get_key_info(struct apple_smc *smc, smc_key key, struct apple_smc_key_info *info) +{ + u8 key_info[6]; + int ret; + + ret = apple_smc_cmd(smc, SMC_MSG_GET_KEY_INFO, key, 0, 0, NULL); + if (ret >= 0 && info) { + memcpy_fromio(key_info, smc->shmem.iomem, sizeof(key_info)); + info->size = key_info[0]; + info->type_code = get_unaligned_be32(&key_info[1]); + info->flags = key_info[5]; + } + return ret; +} +EXPORT_SYMBOL(apple_smc_get_key_info); + +int apple_smc_enter_atomic(struct apple_smc *smc) +{ + guard(mutex)(&smc->mutex); + + /* + * Disable notifications since this is called before shutdown and no + * notification handler will be able to handle the notification + * using atomic operations only. Also ignore any failure here + * because we're about to shut down or reboot anyway. + * We can't use apple_smc_write_flag here since that would try to lock + * smc->mutex again. + */ + const u8 flag = 0; + + apple_smc_rw_locked(smc, SMC_KEY(NTAP), &flag, sizeof(flag), NULL, 0); + + smc->atomic_mode = true; + + return 0; +} +EXPORT_SYMBOL(apple_smc_enter_atomic); + +int apple_smc_write_atomic(struct apple_smc *smc, smc_key key, const void *buf, size_t size) +{ + guard(spinlock_irqsave)(&smc->lock); + u8 result; + int ret; + u64 msg; + + if (size > SMC_MAX_SIZE || size == 0) + return -EINVAL; + + if (smc->boot_stage != APPLE_SMC_INITIALIZED) + return -EIO; + if (!smc->atomic_mode) + return -EIO; + + memcpy_toio(smc->shmem.iomem, buf, size); + smc->msg_id = (smc->msg_id + 1) & 0xf; + msg = (FIELD_PREP(SMC_MSG, SMC_MSG_WRITE_KEY) | + FIELD_PREP(SMC_SIZE, size) | + FIELD_PREP(SMC_ID, smc->msg_id) | + FIELD_PREP(SMC_DATA, key)); + smc->atomic_pending = true; + + ret = apple_rtkit_send_message(smc->rtk, SMC_ENDPOINT, msg, NULL, true); + if (ret < 0) { + dev_err(smc->dev, "Failed to send command (%d)\n", ret); + return ret; + } + + while (smc->atomic_pending) { + ret = apple_rtkit_poll(smc->rtk); + if (ret < 0) { + dev_err(smc->dev, "RTKit poll failed (%llx)", msg); + return ret; + } + udelay(100); + } + + if (FIELD_GET(SMC_ID, smc->cmd_ret) != smc->msg_id) { + dev_err(smc->dev, "Command sequence mismatch (expected %d, got %d)\n", + smc->msg_id, (unsigned int)FIELD_GET(SMC_ID, smc->cmd_ret)); + return -EIO; + } + + result = FIELD_GET(SMC_RESULT, smc->cmd_ret); + if (result) + return -EIO; + + return FIELD_GET(SMC_SIZE, smc->cmd_ret); +} +EXPORT_SYMBOL(apple_smc_write_atomic); + +static void apple_smc_rtkit_crashed(void *cookie, const void *bfr, size_t bfr_len) +{ + struct apple_smc *smc = cookie; + + smc->boot_stage = APPLE_SMC_ERROR_CRASHED; + dev_err(smc->dev, "SMC crashed! Your system will reboot in a few seconds...\n"); +} + +static int apple_smc_rtkit_shmem_setup(void *cookie, struct apple_rtkit_shmem *bfr) +{ + struct apple_smc *smc = cookie; + size_t bfr_end; + + if (!bfr->iova) { + dev_err(smc->dev, "RTKit wants a RAM buffer\n"); + return -EIO; + } + + if (check_add_overflow(bfr->iova, bfr->size - 1, &bfr_end)) + return -EFAULT; + + if (bfr->iova < smc->sram->start || bfr->iova > smc->sram->end || + bfr_end > smc->sram->end) { + dev_err(smc->dev, "RTKit buffer request outside SRAM region: [0x%llx, 0x%llx]\n", + (unsigned long long)bfr->iova, + (unsigned long long)bfr_end); + return -EFAULT; + } + + bfr->iomem = smc->sram_base + (bfr->iova - smc->sram->start); + bfr->is_mapped = true; + + return 0; +} + +static bool apple_smc_rtkit_recv_early(void *cookie, u8 endpoint, u64 message) +{ + struct apple_smc *smc = cookie; + + if (endpoint != SMC_ENDPOINT) { + dev_warn(smc->dev, "Received message for unknown endpoint 0x%x\n", endpoint); + return false; + } + + if (smc->boot_stage == APPLE_SMC_BOOTING) { + int ret; + + smc->shmem.iova = message; + smc->shmem.size = SMC_SHMEM_SIZE; + ret = apple_smc_rtkit_shmem_setup(smc, &smc->shmem); + if (ret < 0) { + smc->boot_stage = APPLE_SMC_ERROR_NO_SHMEM; + dev_err(smc->dev, "Failed to initialize shared memory (%d)\n", ret); + } else { + smc->boot_stage = APPLE_SMC_INITIALIZED; + } + complete(&smc->init_done); + } else if (FIELD_GET(SMC_MSG, message) == SMC_MSG_NOTIFICATION) { + /* Handle these in the RTKit worker thread */ + return false; + } else { + smc->cmd_ret = message; + if (smc->atomic_pending) + smc->atomic_pending = false; + else + complete(&smc->cmd_done); + } + + return true; +} + +static void apple_smc_rtkit_recv(void *cookie, u8 endpoint, u64 message) +{ + struct apple_smc *smc = cookie; + + if (endpoint != SMC_ENDPOINT) { + dev_warn(smc->dev, "Received message for unknown endpoint 0x%x\n", endpoint); + return; + } + + if (FIELD_GET(SMC_MSG, message) != SMC_MSG_NOTIFICATION) { + dev_warn(smc->dev, "Received unknown message from worker: 0x%llx\n", message); + return; + } + + blocking_notifier_call_chain(&smc->event_handlers, FIELD_GET(SMC_DATA, message), NULL); +} + +static const struct apple_rtkit_ops apple_smc_rtkit_ops = { + .crashed = apple_smc_rtkit_crashed, + .recv_message = apple_smc_rtkit_recv, + .recv_message_early = apple_smc_rtkit_recv_early, + .shmem_setup = apple_smc_rtkit_shmem_setup, +}; + +static void apple_smc_rtkit_shutdown(void *data) +{ + struct apple_smc *smc = data; + + /* Shut down SMC firmware, if it's not completely wedged */ + if (apple_rtkit_is_running(smc->rtk)) + apple_rtkit_quiesce(smc->rtk); +} + +static void apple_smc_disable_notifications(void *data) +{ + struct apple_smc *smc = data; + + apple_smc_write_flag(smc, SMC_KEY(NTAP), false); +} + +static int apple_smc_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct apple_smc *smc; + __be32 count; + int ret; + + smc = devm_kzalloc(dev, sizeof(*smc), GFP_KERNEL); + if (!smc) + return -ENOMEM; + + mutex_init(&smc->mutex); + smc->dev = &pdev->dev; + smc->sram_base = devm_platform_get_and_ioremap_resource(pdev, 1, &smc->sram); + if (IS_ERR(smc->sram_base)) + return dev_err_probe(dev, PTR_ERR(smc->sram_base), "Failed to map SRAM region"); + + smc->rtk = devm_apple_rtkit_init(dev, smc, NULL, 0, &apple_smc_rtkit_ops); + if (IS_ERR(smc->rtk)) + return dev_err_probe(dev, PTR_ERR(smc->rtk), "Failed to initialize RTKit"); + + smc->boot_stage = APPLE_SMC_BOOTING; + ret = apple_rtkit_wake(smc->rtk); + if (ret) + return dev_err_probe(dev, ret, "Failed to wake up SMC"); + + ret = devm_add_action_or_reset(dev, apple_smc_rtkit_shutdown, smc); + if (ret) + return ret; + + ret = apple_rtkit_start_ep(smc->rtk, SMC_ENDPOINT); + if (ret) + return dev_err_probe(dev, ret, "Failed to start SMC endpoint"); + + init_completion(&smc->init_done); + init_completion(&smc->cmd_done); + + ret = apple_rtkit_send_message(smc->rtk, SMC_ENDPOINT, + FIELD_PREP(SMC_MSG, SMC_MSG_INITIALIZE), NULL, false); + if (ret) + return dev_err_probe(dev, ret, "Failed to send init message"); + + if (wait_for_completion_timeout(&smc->init_done, msecs_to_jiffies(SMC_TIMEOUT_MS)) == 0) { + dev_err(dev, "Timed out initializing SMC"); + return -ETIMEDOUT; + } + + if (smc->boot_stage != APPLE_SMC_INITIALIZED) { + dev_err(dev, "SMC failed to boot successfully, boot stage=%d\n", smc->boot_stage); + return -EIO; + } + + dev_set_drvdata(&pdev->dev, smc); + BLOCKING_INIT_NOTIFIER_HEAD(&smc->event_handlers); + + ret = apple_smc_read(smc, SMC_KEY(#KEY), &count, sizeof(count)); + if (ret >= 0 && ret != sizeof(count)) + ret = -EINVAL; + if (ret < 0) + return dev_err_probe(smc->dev, ret, "Failed to get key count"); + smc->key_count = be32_to_cpu(count); + + /* Enable notifications */ + apple_smc_write_flag(smc, SMC_KEY(NTAP), true); + ret = devm_add_action_or_reset(dev, apple_smc_disable_notifications, smc); + if (ret) + return ret; + + ret = devm_mfd_add_devices(smc->dev, PLATFORM_DEVID_NONE, + apple_smc_devs, ARRAY_SIZE(apple_smc_devs), + NULL, 0, NULL); + if (ret) + return dev_err_probe(smc->dev, ret, "Failed to register sub-devices"); + + + return 0; +} + +static const struct of_device_id apple_smc_of_match[] = { + { .compatible = "apple,t8103-smc" }, + { .compatible = "apple,smc" }, + {}, +}; +MODULE_DEVICE_TABLE(of, apple_smc_of_match); + +static struct platform_driver apple_smc_driver = { + .driver = { + .name = "macsmc", + .of_match_table = apple_smc_of_match, + }, + .probe = apple_smc_probe, +}; +module_platform_driver(apple_smc_driver); + +MODULE_AUTHOR("Hector Martin "); +MODULE_AUTHOR("Sven Peter "); +MODULE_LICENSE("Dual MIT/GPL"); +MODULE_DESCRIPTION("Apple SMC driver"); -- cgit v1.3.1