--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2017 Arm Ltd.
+#define pr_fmt(fmt) "sdei: " fmt
+
+#include <linux/acpi.h>
+#include <linux/arm_sdei.h>
+#include <linux/arm-smccc.h>
+#include <linux/bitops.h>
+#include <linux/compiler.h>
+#include <linux/errno.h>
+#include <linux/hardirq.h>
+#include <linux/kernel.h>
+#include <linux/kprobes.h>
+#include <linux/kvm_host.h>
+#include <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/percpu.h>
+#include <linux/platform_device.h>
+#include <linux/ptrace.h>
+#include <linux/preempt.h>
+#include <linux/slab.h>
+#include <linux/smp.h>
+#include <linux/spinlock.h>
+#include <linux/uaccess.h>
+
+/*
+ * The call to use to reach the firmware.
+ */
+static asmlinkage void (*sdei_firmware_call)(unsigned long function_id,
+ unsigned long arg0, unsigned long arg1,
+ unsigned long arg2, unsigned long arg3,
+ unsigned long arg4, struct arm_smccc_res *res);
+
+/* entry point from firmware to arch asm code */
+static unsigned long sdei_entry_point;
+
+struct sdei_event {
+ struct list_head list;
+ u32 event_num;
+ u8 type;
+ u8 priority;
+
+ /* This pointer is handed to firmware as the event argument. */
+ struct sdei_registered_event *registered;
+};
+
+/* Take the mutex for any API call or modification. Take the mutex first. */
+static DEFINE_MUTEX(sdei_events_lock);
+
+/* and then hold this when modifying the list */
+static DEFINE_SPINLOCK(sdei_list_lock);
+static LIST_HEAD(sdei_list);
+
+static int sdei_to_linux_errno(unsigned long sdei_err)
+{
+ switch (sdei_err) {
+ case SDEI_NOT_SUPPORTED:
+ return -EOPNOTSUPP;
+ case SDEI_INVALID_PARAMETERS:
+ return -EINVAL;
+ case SDEI_DENIED:
+ return -EPERM;
+ case SDEI_PENDING:
+ return -EINPROGRESS;
+ case SDEI_OUT_OF_RESOURCE:
+ return -ENOMEM;
+ }
+
+ /* Not an error value ... */
+ return sdei_err;
+}
+
+/*
+ * If x0 is any of these values, then the call failed, use sdei_to_linux_errno()
+ * to translate.
+ */
+static int sdei_is_err(struct arm_smccc_res *res)
+{
+ switch (res->a0) {
+ case SDEI_NOT_SUPPORTED:
+ case SDEI_INVALID_PARAMETERS:
+ case SDEI_DENIED:
+ case SDEI_PENDING:
+ case SDEI_OUT_OF_RESOURCE:
+ return true;
+ }
+
+ return false;
+}
+
+static int invoke_sdei_fn(unsigned long function_id, unsigned long arg0,
+ unsigned long arg1, unsigned long arg2,
+ unsigned long arg3, unsigned long arg4,
+ u64 *result)
+{
+ int err = 0;
+ struct arm_smccc_res res;
+
+ if (sdei_firmware_call) {
+ sdei_firmware_call(function_id, arg0, arg1, arg2, arg3, arg4,
+ &res);
+ if (sdei_is_err(&res))
+ err = sdei_to_linux_errno(res.a0);
+ } else {
+ /*
+ * !sdei_firmware_call means we failed to probe or called
+ * sdei_mark_interface_broken(). -EIO is not an error returned
+ * by sdei_to_linux_errno() and is used to suppress messages
+ * from this driver.
+ */
+ err = -EIO;
+ res.a0 = SDEI_NOT_SUPPORTED;
+ }
+
+ if (result)
+ *result = res.a0;
+
+ return err;
+}
+
+static struct sdei_event *sdei_event_find(u32 event_num)
+{
+ struct sdei_event *e, *found = NULL;
+
+ lockdep_assert_held(&sdei_events_lock);
+
+ spin_lock(&sdei_list_lock);
+ list_for_each_entry(e, &sdei_list, list) {
+ if (e->event_num == event_num) {
+ found = e;
+ break;
+ }
+ }
+ spin_unlock(&sdei_list_lock);
+
+ return found;
+}
+
+int sdei_api_event_context(u32 query, u64 *result)
+{
+ return invoke_sdei_fn(SDEI_1_0_FN_SDEI_EVENT_CONTEXT, query, 0, 0, 0, 0,
+ result);
+}
+NOKPROBE_SYMBOL(sdei_api_event_context);
+
+static int sdei_api_event_get_info(u32 event, u32 info, u64 *result)
+{
+ return invoke_sdei_fn(SDEI_1_0_FN_SDEI_EVENT_GET_INFO, event, info, 0,
+ 0, 0, result);
+}
+
+static struct sdei_event *sdei_event_create(u32 event_num,
+ sdei_event_callback *cb,
+ void *cb_arg)
+{
+ int err;
+ u64 result;
+ struct sdei_event *event;
+ struct sdei_registered_event *reg;
+
+ lockdep_assert_held(&sdei_events_lock);
+
+ event = kzalloc(sizeof(*event), GFP_KERNEL);
+ if (!event)
+ return ERR_PTR(-ENOMEM);
+
+ INIT_LIST_HEAD(&event->list);
+ event->event_num = event_num;
+
+ err = sdei_api_event_get_info(event_num, SDEI_EVENT_INFO_EV_PRIORITY,
+ &result);
+ if (err) {
+ kfree(event);
+ return ERR_PTR(err);
+ }
+ event->priority = result;
+
+ err = sdei_api_event_get_info(event_num, SDEI_EVENT_INFO_EV_TYPE,
+ &result);
+ if (err) {
+ kfree(event);
+ return ERR_PTR(err);
+ }
+ event->type = result;
+
+ if (event->type == SDEI_EVENT_TYPE_SHARED) {
+ reg = kzalloc(sizeof(*reg), GFP_KERNEL);
+ if (!reg) {
+ kfree(event);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ reg->event_num = event_num;
+ reg->priority = event->priority;
+
+ reg->callback = cb;
+ reg->callback_arg = cb_arg;
+ event->registered = reg;
+ }
+
+ if (sdei_event_find(event_num)) {
+ kfree(event->registered);
+ kfree(event);
+ event = ERR_PTR(-EBUSY);
+ } else {
+ spin_lock(&sdei_list_lock);
+ list_add(&event->list, &sdei_list);
+ spin_unlock(&sdei_list_lock);
+ }
+
+ return event;
+}
+
+static void sdei_event_destroy(struct sdei_event *event)
+{
+ lockdep_assert_held(&sdei_events_lock);
+
+ spin_lock(&sdei_list_lock);
+ list_del(&event->list);
+ spin_unlock(&sdei_list_lock);
+
+ if (event->type == SDEI_EVENT_TYPE_SHARED)
+ kfree(event->registered);
+
+ kfree(event);
+}
+
+static int sdei_api_get_version(u64 *version)
+{
+ return invoke_sdei_fn(SDEI_1_0_FN_SDEI_VERSION, 0, 0, 0, 0, 0, version);
+}
+
+int sdei_mask_local_cpu(void)
+{
+ int err;
+
+ WARN_ON_ONCE(preemptible());
+
+ err = invoke_sdei_fn(SDEI_1_0_FN_SDEI_PE_MASK, 0, 0, 0, 0, 0, NULL);
+ if (err && err != -EIO) {
+ pr_warn_once("failed to mask CPU[%u]: %d\n",
+ smp_processor_id(), err);
+ return err;
+ }
+
+ return 0;
+}
+
+static void _ipi_mask_cpu(void *ignored)
+{
+ sdei_mask_local_cpu();
+}
+
+int sdei_unmask_local_cpu(void)
+{
+ int err;
+
+ WARN_ON_ONCE(preemptible());
+
+ err = invoke_sdei_fn(SDEI_1_0_FN_SDEI_PE_UNMASK, 0, 0, 0, 0, 0, NULL);
+ if (err && err != -EIO) {
+ pr_warn_once("failed to unmask CPU[%u]: %d\n",
+ smp_processor_id(), err);
+ return err;
+ }
+
+ return 0;
+}
+
+static void _ipi_unmask_cpu(void *ignored)
+{
+ sdei_unmask_local_cpu();
+}
+
+static void _ipi_private_reset(void *ignored)
+{
+ int err;
+
+ err = invoke_sdei_fn(SDEI_1_0_FN_SDEI_PRIVATE_RESET, 0, 0, 0, 0, 0,
+ NULL);
+ if (err && err != -EIO)
+ pr_warn_once("failed to reset CPU[%u]: %d\n",
+ smp_processor_id(), err);
+}
+
+static int sdei_api_shared_reset(void)
+{
+ return invoke_sdei_fn(SDEI_1_0_FN_SDEI_SHARED_RESET, 0, 0, 0, 0, 0,
+ NULL);
+}
+
+static void sdei_mark_interface_broken(void)
+{
+ pr_err("disabling SDEI firmware interface\n");
+ on_each_cpu(&_ipi_mask_cpu, NULL, true);
+ sdei_firmware_call = NULL;
+}
+
+static int sdei_platform_reset(void)
+{
+ int err;
+
+ on_each_cpu(&_ipi_private_reset, NULL, true);
+ err = sdei_api_shared_reset();
+ if (err) {
+ pr_err("Failed to reset platform: %d\n", err);
+ sdei_mark_interface_broken();
+ }
+
+ return err;
+}
+
+static int sdei_api_event_enable(u32 event_num)
+{
+ return invoke_sdei_fn(SDEI_1_0_FN_SDEI_EVENT_ENABLE, event_num, 0, 0, 0,
+ 0, NULL);
+}
+
+int sdei_event_enable(u32 event_num)
+{
+ int err = -EINVAL;
+ struct sdei_event *event;
+
+ mutex_lock(&sdei_events_lock);
+ event = sdei_event_find(event_num);
+ if (!event) {
+ mutex_unlock(&sdei_events_lock);
+ return -ENOENT;
+ }
+
+ if (event->type == SDEI_EVENT_TYPE_SHARED)
+ err = sdei_api_event_enable(event->event_num);
+ mutex_unlock(&sdei_events_lock);
+
+ return err;
+}
+EXPORT_SYMBOL(sdei_event_enable);
+
+static int sdei_api_event_disable(u32 event_num)
+{
+ return invoke_sdei_fn(SDEI_1_0_FN_SDEI_EVENT_DISABLE, event_num, 0, 0,
+ 0, 0, NULL);
+}
+
+int sdei_event_disable(u32 event_num)
+{
+ int err = -EINVAL;
+ struct sdei_event *event;
+
+ mutex_lock(&sdei_events_lock);
+ event = sdei_event_find(event_num);
+ if (!event) {
+ mutex_unlock(&sdei_events_lock);
+ return -ENOENT;
+ }
+
+ if (event->type == SDEI_EVENT_TYPE_SHARED)
+ err = sdei_api_event_disable(event->event_num);
+ mutex_unlock(&sdei_events_lock);
+
+ return err;
+}
+EXPORT_SYMBOL(sdei_event_disable);
+
+static int sdei_api_event_unregister(u32 event_num)
+{
+ return invoke_sdei_fn(SDEI_1_0_FN_SDEI_EVENT_UNREGISTER, event_num, 0,
+ 0, 0, 0, NULL);
+}
+
+static int _sdei_event_unregister(struct sdei_event *event)
+{
+ lockdep_assert_held(&sdei_events_lock);
+
+ if (event->type == SDEI_EVENT_TYPE_SHARED)
+ return sdei_api_event_unregister(event->event_num);
+
+ return -EINVAL;
+}
+
+int sdei_event_unregister(u32 event_num)
+{
+ int err;
+ struct sdei_event *event;
+
+ WARN_ON(in_nmi());
+
+ mutex_lock(&sdei_events_lock);
+ event = sdei_event_find(event_num);
+ do {
+ if (!event) {
+ pr_warn("Event %u not registered\n", event_num);
+ err = -ENOENT;
+ break;
+ }
+
+ err = _sdei_event_unregister(event);
+ if (err)
+ break;
+
+ sdei_event_destroy(event);
+ } while (0);
+ mutex_unlock(&sdei_events_lock);
+
+ return err;
+}
+EXPORT_SYMBOL(sdei_event_unregister);
+
+static int sdei_api_event_register(u32 event_num, unsigned long entry_point,
+ void *arg, u64 flags, u64 affinity)
+{
+ return invoke_sdei_fn(SDEI_1_0_FN_SDEI_EVENT_REGISTER, event_num,
+ (unsigned long)entry_point, (unsigned long)arg,
+ flags, affinity, NULL);
+}
+
+static int _sdei_event_register(struct sdei_event *event)
+{
+ lockdep_assert_held(&sdei_events_lock);
+
+ if (event->type == SDEI_EVENT_TYPE_SHARED)
+ return sdei_api_event_register(event->event_num,
+ sdei_entry_point,
+ event->registered,
+ SDEI_EVENT_REGISTER_RM_ANY, 0);
+
+ return -EINVAL;
+}
+
+int sdei_event_register(u32 event_num, sdei_event_callback *cb, void *arg)
+{
+ int err;
+ struct sdei_event *event;
+
+ WARN_ON(in_nmi());
+
+ mutex_lock(&sdei_events_lock);
+ do {
+ if (sdei_event_find(event_num)) {
+ pr_warn("Event %u already registered\n", event_num);
+ err = -EBUSY;
+ break;
+ }
+
+ event = sdei_event_create(event_num, cb, arg);
+ if (IS_ERR(event)) {
+ err = PTR_ERR(event);
+ pr_warn("Failed to create event %u: %d\n", event_num,
+ err);
+ break;
+ }
+
+ err = _sdei_event_register(event);
+ if (err) {
+ sdei_event_destroy(event);
+ pr_warn("Failed to register event %u: %d\n", event_num,
+ err);
+ }
+ } while (0);
+ mutex_unlock(&sdei_events_lock);
+
+ return err;
+}
+EXPORT_SYMBOL(sdei_event_register);
+
+static void sdei_smccc_smc(unsigned long function_id,
+ unsigned long arg0, unsigned long arg1,
+ unsigned long arg2, unsigned long arg3,
+ unsigned long arg4, struct arm_smccc_res *res)
+{
+ arm_smccc_smc(function_id, arg0, arg1, arg2, arg3, arg4, 0, 0, res);
+}
+
+static void sdei_smccc_hvc(unsigned long function_id,
+ unsigned long arg0, unsigned long arg1,
+ unsigned long arg2, unsigned long arg3,
+ unsigned long arg4, struct arm_smccc_res *res)
+{
+ arm_smccc_hvc(function_id, arg0, arg1, arg2, arg3, arg4, 0, 0, res);
+}
+
+static int sdei_get_conduit(struct platform_device *pdev)
+{
+ const char *method;
+ struct device_node *np = pdev->dev.of_node;
+
+ sdei_firmware_call = NULL;
+ if (np) {
+ if (of_property_read_string(np, "method", &method)) {
+ pr_warn("missing \"method\" property\n");
+ return CONDUIT_INVALID;
+ }
+
+ if (!strcmp("hvc", method)) {
+ sdei_firmware_call = &sdei_smccc_hvc;
+ return CONDUIT_HVC;
+ } else if (!strcmp("smc", method)) {
+ sdei_firmware_call = &sdei_smccc_smc;
+ return CONDUIT_SMC;
+ }
+
+ pr_warn("invalid \"method\" property: %s\n", method);
+ }
+
+ return CONDUIT_INVALID;
+}
+
+static int sdei_probe(struct platform_device *pdev)
+{
+ int err;
+ u64 ver = 0;
+ int conduit;
+
+ conduit = sdei_get_conduit(pdev);
+ if (!sdei_firmware_call)
+ return 0;
+
+ err = sdei_api_get_version(&ver);
+ if (err == -EOPNOTSUPP)
+ pr_err("advertised but not implemented in platform firmware\n");
+ if (err) {
+ pr_err("Failed to get SDEI version: %d\n", err);
+ sdei_mark_interface_broken();
+ return err;
+ }
+
+ pr_info("SDEIv%d.%d (0x%x) detected in firmware.\n",
+ (int)SDEI_VERSION_MAJOR(ver), (int)SDEI_VERSION_MINOR(ver),
+ (int)SDEI_VERSION_VENDOR(ver));
+
+ if (SDEI_VERSION_MAJOR(ver) != 1) {
+ pr_warn("Conflicting SDEI version detected.\n");
+ sdei_mark_interface_broken();
+ return -EINVAL;
+ }
+
+ err = sdei_platform_reset();
+ if (err)
+ return err;
+
+ sdei_entry_point = sdei_arch_get_entry_point(conduit);
+ if (!sdei_entry_point) {
+ /* Not supported due to hardware or boot configuration */
+ sdei_mark_interface_broken();
+ return 0;
+ }
+
+ on_each_cpu(&_ipi_unmask_cpu, NULL, false);
+
+ return 0;
+}
+
+static const struct of_device_id sdei_of_match[] = {
+ { .compatible = "arm,sdei-1.0" },
+ {}
+};
+
+static struct platform_driver sdei_driver = {
+ .driver = {
+ .name = "sdei",
+ .of_match_table = sdei_of_match,
+ },
+ .probe = sdei_probe,
+};
+
+static bool __init sdei_present_dt(void)
+{
+ struct platform_device *pdev;
+ struct device_node *np, *fw_np;
+
+ fw_np = of_find_node_by_name(NULL, "firmware");
+ if (!fw_np)
+ return false;
+
+ np = of_find_matching_node(fw_np, sdei_of_match);
+ of_node_put(fw_np);
+ if (!np)
+ return false;
+
+ pdev = of_platform_device_create(np, sdei_driver.driver.name, NULL);
+ of_node_put(np);
+ if (IS_ERR(pdev))
+ return false;
+
+ return true;
+}
+
+static int __init sdei_init(void)
+{
+ if (sdei_present_dt())
+ platform_driver_register(&sdei_driver);
+
+ return 0;
+}
+
+subsys_initcall_sync(sdei_init);
+
+int sdei_event_handler(struct pt_regs *regs,
+ struct sdei_registered_event *arg)
+{
+ int err;
+ mm_segment_t orig_addr_limit;
+ u32 event_num = arg->event_num;
+
+ orig_addr_limit = get_fs();
+ set_fs(USER_DS);
+
+ err = arg->callback(event_num, regs, arg->callback_arg);
+ if (err)
+ pr_err_ratelimited("event %u on CPU %u failed with error: %d\n",
+ event_num, smp_processor_id(), err);
+
+ set_fs(orig_addr_limit);
+
+ return err;
+}
+NOKPROBE_SYMBOL(sdei_event_handler);
projects / users / hch / xfs.git / commitdiff