--- /dev/null
+/* acpi_thermal_rel.c driver for exporting ACPI thermal relationship
+ *
+ * Copyright (c) 2014 Intel Corp
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ */
+
+/*
+ * Two functionalities included:
+ * 1. Export _TRT, _ART, via misc device interface to the userspace.
+ * 2. Provide parsing result to kernel drivers
+ *
+ */
+#include <linux/init.h>
+#include <linux/export.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/acpi.h>
+#include <linux/uaccess.h>
+#include <linux/miscdevice.h>
+#include "acpi_thermal_rel.h"
+
+static acpi_handle acpi_thermal_rel_handle;
+static DEFINE_SPINLOCK(acpi_thermal_rel_chrdev_lock);
+static int acpi_thermal_rel_chrdev_count; /* #times opened */
+static int acpi_thermal_rel_chrdev_exclu; /* already open exclusive? */
+
+static int acpi_thermal_rel_open(struct inode *inode, struct file *file)
+{
+ spin_lock(&acpi_thermal_rel_chrdev_lock);
+ if (acpi_thermal_rel_chrdev_exclu ||
+ (acpi_thermal_rel_chrdev_count && (file->f_flags & O_EXCL))) {
+ spin_unlock(&acpi_thermal_rel_chrdev_lock);
+ return -EBUSY;
+ }
+
+ if (file->f_flags & O_EXCL)
+ acpi_thermal_rel_chrdev_exclu = 1;
+ acpi_thermal_rel_chrdev_count++;
+
+ spin_unlock(&acpi_thermal_rel_chrdev_lock);
+
+ return nonseekable_open(inode, file);
+}
+
+static int acpi_thermal_rel_release(struct inode *inode, struct file *file)
+{
+ spin_lock(&acpi_thermal_rel_chrdev_lock);
+ acpi_thermal_rel_chrdev_count--;
+ acpi_thermal_rel_chrdev_exclu = 0;
+ spin_unlock(&acpi_thermal_rel_chrdev_lock);
+
+ return 0;
+}
+
+/**
+ * acpi_parse_trt - Thermal Relationship Table _TRT for passive cooling
+ *
+ * @handle: ACPI handle of the device contains _TRT
+ * @art_count: the number of valid entries resulted from parsing _TRT
+ * @artp: pointer to pointer of array of art entries in parsing result
+ * @create_dev: whether to create platform devices for target and source
+ *
+ */
+int acpi_parse_trt(acpi_handle handle, int *trt_count, struct trt **trtp,
+ bool create_dev)
+{
+ acpi_status status;
+ int result = 0;
+ int i;
+ int nr_bad_entries = 0;
+ struct trt *trts;
+ struct acpi_device *adev;
+ union acpi_object *p;
+ struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+ struct acpi_buffer element = { 0, NULL };
+ struct acpi_buffer trt_format = { sizeof("RRNNNNNN"), "RRNNNNNN" };
+
+ if (!acpi_has_method(handle, "_TRT"))
+ return -ENODEV;
+
+ status = acpi_evaluate_object(handle, "_TRT", NULL, &buffer);
+ if (ACPI_FAILURE(status))
+ return -ENODEV;
+
+ p = buffer.pointer;
+ if (!p || (p->type != ACPI_TYPE_PACKAGE)) {
+ pr_err("Invalid _TRT data\n");
+ result = -EFAULT;
+ goto end;
+ }
+
+ *trt_count = p->package.count;
+ trts = kzalloc(*trt_count * sizeof(struct trt), GFP_KERNEL);
+ if (!trts) {
+ result = -ENOMEM;
+ goto end;
+ }
+
+ for (i = 0; i < *trt_count; i++) {
+ struct trt *trt = &trts[i - nr_bad_entries];
+
+ element.length = sizeof(struct trt);
+ element.pointer = trt;
+
+ status = acpi_extract_package(&(p->package.elements[i]),
+ &trt_format, &element);
+ if (ACPI_FAILURE(status)) {
+ nr_bad_entries++;
+ pr_warn("_TRT package %d is invalid, ignored\n", i);
+ continue;
+ }
+ if (!create_dev)
+ continue;
+
+ result = acpi_bus_get_device(trt->source, &adev);
+ if (result)
+ pr_warn("Failed to get source ACPI device\n");
+
+ result = acpi_bus_get_device(trt->target, &adev);
+ if (result)
+ pr_warn("Failed to get target ACPI device\n");
+ }
+
+ result = 0;
+
+ *trtp = trts;
+ /* don't count bad entries */
+ *trt_count -= nr_bad_entries;
+end:
+ kfree(buffer.pointer);
+ return result;
+}
+EXPORT_SYMBOL(acpi_parse_trt);
+
+/**
+ * acpi_parse_art - Parse Active Relationship Table _ART
+ *
+ * @handle: ACPI handle of the device contains _ART
+ * @art_count: the number of valid entries resulted from parsing _ART
+ * @artp: pointer to pointer of array of art entries in parsing result
+ * @create_dev: whether to create platform devices for target and source
+ *
+ */
+int acpi_parse_art(acpi_handle handle, int *art_count, struct art **artp,
+ bool create_dev)
+{
+ acpi_status status;
+ int result = 0;
+ int i;
+ int nr_bad_entries = 0;
+ struct art *arts;
+ struct acpi_device *adev;
+ union acpi_object *p;
+ struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+ struct acpi_buffer element = { 0, NULL };
+ struct acpi_buffer art_format = {
+ sizeof("RRNNNNNNNNNNN"), "RRNNNNNNNNNNN" };
+
+ if (!acpi_has_method(handle, "_ART"))
+ return -ENODEV;
+
+ status = acpi_evaluate_object(handle, "_ART", NULL, &buffer);
+ if (ACPI_FAILURE(status))
+ return -ENODEV;
+
+ p = buffer.pointer;
+ if (!p || (p->type != ACPI_TYPE_PACKAGE)) {
+ pr_err("Invalid _ART data\n");
+ result = -EFAULT;
+ goto end;
+ }
+
+ /* ignore p->package.elements[0], as this is _ART Revision field */
+ *art_count = p->package.count - 1;
+ arts = kzalloc(*art_count * sizeof(struct art), GFP_KERNEL);
+ if (!arts) {
+ result = -ENOMEM;
+ goto end;
+ }
+
+ for (i = 0; i < *art_count; i++) {
+ struct art *art = &arts[i - nr_bad_entries];
+
+ element.length = sizeof(struct art);
+ element.pointer = art;
+
+ status = acpi_extract_package(&(p->package.elements[i + 1]),
+ &art_format, &element);
+ if (ACPI_FAILURE(status)) {
+ pr_warn("_ART package %d is invalid, ignored", i);
+ nr_bad_entries++;
+ continue;
+ }
+ if (!create_dev)
+ continue;
+
+ if (art->source) {
+ result = acpi_bus_get_device(art->source, &adev);
+ if (result)
+ pr_warn("Failed to get source ACPI device\n");
+ }
+ if (art->target) {
+ result = acpi_bus_get_device(art->target, &adev);
+ if (result)
+ pr_warn("Failed to get source ACPI device\n");
+ }
+ }
+
+ *artp = arts;
+ /* don't count bad entries */
+ *art_count -= nr_bad_entries;
+end:
+ kfree(buffer.pointer);
+ return result;
+}
+EXPORT_SYMBOL(acpi_parse_art);
+
+
+/* get device name from acpi handle */
+static void get_single_name(acpi_handle handle, char *name)
+{
+ struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER};
+
+ if (ACPI_FAILURE(acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer)))
+ pr_warn("Failed get name from handle\n");
+ else {
+ memcpy(name, buffer.pointer, ACPI_NAME_SIZE);
+ kfree(buffer.pointer);
+ }
+}
+
+static int fill_art(char __user *ubuf)
+{
+ int i;
+ int ret;
+ int count;
+ int art_len;
+ struct art *arts = NULL;
+ union art_object *art_user;
+
+ ret = acpi_parse_art(acpi_thermal_rel_handle, &count, &arts, false);
+ if (ret)
+ goto free_art;
+ art_len = count * sizeof(union art_object);
+ art_user = kzalloc(art_len, GFP_KERNEL);
+ if (!art_user) {
+ ret = -ENOMEM;
+ goto free_art;
+ }
+ /* now fill in user art data */
+ for (i = 0; i < count; i++) {
+ /* userspace art needs device name instead of acpi reference */
+ get_single_name(arts[i].source, art_user[i].source_device);
+ get_single_name(arts[i].target, art_user[i].target_device);
+ /* copy the rest int data in addition to source and target */
+ memcpy(&art_user[i].weight, &arts[i].weight,
+ sizeof(u64) * (ACPI_NR_ART_ELEMENTS - 2));
+ }
+
+ if (copy_to_user(ubuf, art_user, art_len))
+ ret = -EFAULT;
+ kfree(art_user);
+free_art:
+ kfree(arts);
+ return ret;
+}
+
+static int fill_trt(char __user *ubuf)
+{
+ int i;
+ int ret;
+ int count;
+ int trt_len;
+ struct trt *trts = NULL;
+ union trt_object *trt_user;
+
+ ret = acpi_parse_trt(acpi_thermal_rel_handle, &count, &trts, false);
+ if (ret)
+ goto free_trt;
+ trt_len = count * sizeof(union trt_object);
+ trt_user = kzalloc(trt_len, GFP_KERNEL);
+ if (!trt_user) {
+ ret = -ENOMEM;
+ goto free_trt;
+ }
+ /* now fill in user trt data */
+ for (i = 0; i < count; i++) {
+ /* userspace trt needs device name instead of acpi reference */
+ get_single_name(trts[i].source, trt_user[i].source_device);
+ get_single_name(trts[i].target, trt_user[i].target_device);
+ trt_user[i].sample_period = trts[i].sample_period;
+ trt_user[i].influence = trts[i].influence;
+ }
+
+ if (copy_to_user(ubuf, trt_user, trt_len))
+ ret = -EFAULT;
+ kfree(trt_user);
+free_trt:
+ kfree(trts);
+ return ret;
+}
+
+static long acpi_thermal_rel_ioctl(struct file *f, unsigned int cmd,
+ unsigned long __arg)
+{
+ int ret = 0;
+ unsigned long length = 0;
+ int count = 0;
+ char __user *arg = (void __user *)__arg;
+ struct trt *trts = NULL;
+ struct art *arts = NULL;
+
+ switch (cmd) {
+ case ACPI_THERMAL_GET_TRT_COUNT:
+ ret = acpi_parse_trt(acpi_thermal_rel_handle, &count,
+ &trts, false);
+ kfree(trts);
+ if (!ret)
+ return put_user(count, (unsigned long __user *)__arg);
+ return ret;
+ case ACPI_THERMAL_GET_TRT_LEN:
+ ret = acpi_parse_trt(acpi_thermal_rel_handle, &count,
+ &trts, false);
+ kfree(trts);
+ length = count * sizeof(union trt_object);
+ if (!ret)
+ return put_user(length, (unsigned long __user *)__arg);
+ return ret;
+ case ACPI_THERMAL_GET_TRT:
+ return fill_trt(arg);
+ case ACPI_THERMAL_GET_ART_COUNT:
+ ret = acpi_parse_art(acpi_thermal_rel_handle, &count,
+ &arts, false);
+ kfree(arts);
+ if (!ret)
+ return put_user(count, (unsigned long __user *)__arg);
+ return ret;
+ case ACPI_THERMAL_GET_ART_LEN:
+ ret = acpi_parse_art(acpi_thermal_rel_handle, &count,
+ &arts, false);
+ kfree(arts);
+ length = count * sizeof(union art_object);
+ if (!ret)
+ return put_user(length, (unsigned long __user *)__arg);
+ return ret;
+
+ case ACPI_THERMAL_GET_ART:
+ return fill_art(arg);
+
+ default:
+ return -ENOTTY;
+ }
+}
+
+static const struct file_operations acpi_thermal_rel_fops = {
+ .owner = THIS_MODULE,
+ .open = acpi_thermal_rel_open,
+ .release = acpi_thermal_rel_release,
+ .unlocked_ioctl = acpi_thermal_rel_ioctl,
+ .llseek = no_llseek,
+};
+
+static struct miscdevice acpi_thermal_rel_misc_device = {
+ .minor = MISC_DYNAMIC_MINOR,
+ "acpi_thermal_rel",
+ &acpi_thermal_rel_fops
+};
+
+int acpi_thermal_rel_misc_device_add(acpi_handle handle)
+{
+ acpi_thermal_rel_handle = handle;
+
+ return misc_register(&acpi_thermal_rel_misc_device);
+}
+EXPORT_SYMBOL(acpi_thermal_rel_misc_device_add);
+
+int acpi_thermal_rel_misc_device_remove(acpi_handle handle)
+{
+ misc_deregister(&acpi_thermal_rel_misc_device);
+
+ return 0;
+}
+EXPORT_SYMBOL(acpi_thermal_rel_misc_device_remove);
+
+MODULE_AUTHOR("Zhang Rui <rui.zhang@intel.com>");
+MODULE_AUTHOR("Jacob Pan <jacob.jun.pan@intel.com");
+MODULE_DESCRIPTION("Intel acpi thermal rel misc dev driver");
+MODULE_LICENSE("GPL v2");
Code Review / kvmfornfv.git / blobdiff