Orange Pi5 kernel

// SPDX-License-Identifier: GPL-2.0
/*
 * SCLP Store Data support and sysfs interface
 *
 * Copyright IBM Corp. 2017
 */
 
#define KMSG_COMPONENT "sclp_sd"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
 
#include <linux/completion.h>
#include <linux/kobject.h>
#include <linux/list.h>
#include <linux/printk.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/async.h>
#include <linux/export.h>
#include <linux/mutex.h>
 
#include <asm/pgalloc.h>
 
#include "sclp.h"
 
#define SD_EQ_STORE_DATA	0
#define SD_EQ_HALT		1
#define SD_EQ_SIZE		2
 
#define SD_DI_CONFIG		3
 
struct sclp_sd_evbuf {
<------>struct evbuf_header hdr;
<------>u8 eq;
<------>u8 di;
<------>u8 rflags;
<------>u64 :56;
<------>u32 id;
<------>u16 :16;
<------>u8 fmt;
<------>u8 status;
<------>u64 sat;
<------>u64 sa;
<------>u32 esize;
<------>u32 dsize;
} __packed;
 
struct sclp_sd_sccb {
<------>struct sccb_header hdr;
<------>struct sclp_sd_evbuf evbuf;
} __packed __aligned(PAGE_SIZE);
 
/**
 * struct sclp_sd_data - Result of a Store Data request
 * @esize_bytes: Resulting esize in bytes
 * @dsize_bytes: Resulting dsize in bytes
 * @data: Pointer to data - must be released using vfree()
 */
struct sclp_sd_data {
<------>size_t esize_bytes;
<------>size_t dsize_bytes;
<------>void *data;
};
 
/**
 * struct sclp_sd_listener - Listener for asynchronous Store Data response
 * @list: For enqueueing this struct
 * @id: Event ID of response to listen for
 * @completion: Can be used to wait for response
 * @evbuf: Contains the resulting Store Data response after completion
 */
struct sclp_sd_listener {
<------>struct list_head list;
<------>u32 id;
<------>struct completion completion;
<------>struct sclp_sd_evbuf evbuf;
};
 
/**
 * struct sclp_sd_file - Sysfs representation of a Store Data entity
 * @kobj: Kobject
 * @data_attr: Attribute for accessing data contents
 * @data_mutex: Mutex to serialize access and updates to @data
 * @data: Data associated with this entity
 * @di: DI value associated with this entity
 */
struct sclp_sd_file {
<------>struct kobject kobj;
<------>struct bin_attribute data_attr;
<------>struct mutex data_mutex;
<------>struct sclp_sd_data data;
<------>u8 di;
};
#define to_sd_file(x) container_of(x, struct sclp_sd_file, kobj)
 
static struct kset *sclp_sd_kset;
static struct sclp_sd_file *config_file;
 
static LIST_HEAD(sclp_sd_queue);
static DEFINE_SPINLOCK(sclp_sd_queue_lock);
 
/**
 * sclp_sd_listener_add() - Add listener for Store Data responses
 * @listener: Listener to add
 */
static void sclp_sd_listener_add(struct sclp_sd_listener *listener)
{
<------>spin_lock_irq(&sclp_sd_queue_lock);
<------>list_add_tail(&listener->list, &sclp_sd_queue);
<------>spin_unlock_irq(&sclp_sd_queue_lock);
}
 
/**
 * sclp_sd_listener_remove() - Remove listener for Store Data responses
 * @listener: Listener to remove
 */
static void sclp_sd_listener_remove(struct sclp_sd_listener *listener)
{
<------>spin_lock_irq(&sclp_sd_queue_lock);
<------>list_del(&listener->list);
<------>spin_unlock_irq(&sclp_sd_queue_lock);
}
 
/**
 * sclp_sd_listener_init() - Initialize a Store Data response listener
 * @id: Event ID to listen for
 *
 * Initialize a listener for asynchronous Store Data responses. This listener
 * can afterwards be used to wait for a specific response and to retrieve
 * the associated response data.
 */
static void sclp_sd_listener_init(struct sclp_sd_listener *listener, u32 id)
{
<------>memset(listener, 0, sizeof(*listener));
<------>listener->id = id;
<------>init_completion(&listener->completion);
}
 
/**
 * sclp_sd_receiver() - Receiver for Store Data events
 * @evbuf_hdr: Header of received events
 *
 * Process Store Data events and complete listeners with matching event IDs.
 */
static void sclp_sd_receiver(struct evbuf_header *evbuf_hdr)
{
<------>struct sclp_sd_evbuf *evbuf = (struct sclp_sd_evbuf *) evbuf_hdr;
<------>struct sclp_sd_listener *listener;
<------>int found = 0;
 
<------>pr_debug("received event (id=0x%08x)\n", evbuf->id);
<------>spin_lock(&sclp_sd_queue_lock);
<------>list_for_each_entry(listener, &sclp_sd_queue, list) {
<------><------>if (listener->id != evbuf->id)
<------><------><------>continue;
 
<------><------>listener->evbuf = *evbuf;
<------><------>complete(&listener->completion);
<------><------>found = 1;
<------><------>break;
<------>}
<------>spin_unlock(&sclp_sd_queue_lock);
 
<------>if (!found)
<------><------>pr_debug("unsolicited event (id=0x%08x)\n", evbuf->id);
}
 
static struct sclp_register sclp_sd_register = {
<------>.send_mask = EVTYP_STORE_DATA_MASK,
<------>.receive_mask = EVTYP_STORE_DATA_MASK,
<------>.receiver_fn = sclp_sd_receiver,
};
 
/**
 * sclp_sd_sync() - Perform Store Data request synchronously
 * @page: Address of work page - must be below 2GB
 * @eq: Input EQ value
 * @di: Input DI value
 * @sat: Input SAT value
 * @sa: Input SA value used to specify the address of the target buffer
 * @dsize_ptr: Optional pointer to input and output DSIZE value
 * @esize_ptr: Optional pointer to output ESIZE value
 *
 * Perform Store Data request with specified parameters and wait for completion.
 *
 * Return %0 on success and store resulting DSIZE and ESIZE values in
 * @dsize_ptr and @esize_ptr (if provided). Return non-zero on error.
 */
static int sclp_sd_sync(unsigned long page, u8 eq, u8 di, u64 sat, u64 sa,
<------><------><------>u32 *dsize_ptr, u32 *esize_ptr)
{
<------>struct sclp_sd_sccb *sccb = (void *) page;
<------>struct sclp_sd_listener listener;
<------>struct sclp_sd_evbuf *evbuf;
<------>int rc;
 
<------>sclp_sd_listener_init(&listener, (u32) (addr_t) sccb);
<------>sclp_sd_listener_add(&listener);
 
<------>/* Prepare SCCB */
<------>memset(sccb, 0, PAGE_SIZE);
<------>sccb->hdr.length = sizeof(sccb->hdr) + sizeof(sccb->evbuf);
<------>evbuf = &sccb->evbuf;
<------>evbuf->hdr.length = sizeof(*evbuf);
<------>evbuf->hdr.type = EVTYP_STORE_DATA;
<------>evbuf->eq = eq;
<------>evbuf->di = di;
<------>evbuf->id = listener.id;
<------>evbuf->fmt = 1;
<------>evbuf->sat = sat;
<------>evbuf->sa = sa;
<------>if (dsize_ptr)
<------><------>evbuf->dsize = *dsize_ptr;
 
<------>/* Perform command */
<------>pr_debug("request (eq=%d, di=%d, id=0x%08x)\n", eq, di, listener.id);
<------>rc = sclp_sync_request(SCLP_CMDW_WRITE_EVENT_DATA, sccb);
<------>pr_debug("request done (rc=%d)\n", rc);
<------>if (rc)
<------><------>goto out;
 
<------>/* Evaluate response */
<------>if (sccb->hdr.response_code == 0x73f0) {
<------><------>pr_debug("event not supported\n");
<------><------>rc = -EIO;
<------><------>goto out_remove;
<------>}
<------>if (sccb->hdr.response_code != 0x0020 || !(evbuf->hdr.flags & 0x80)) {
<------><------>rc = -EIO;
<------><------>goto out;
<------>}
<------>if (!(evbuf->rflags & 0x80)) {
<------><------>rc = wait_for_completion_interruptible(&listener.completion);
<------><------>if (rc)
<------><------><------>goto out;
<------><------>evbuf = &listener.evbuf;
<------>}
<------>switch (evbuf->status) {
<------>case 0:
<------><------>if (dsize_ptr)
<------><------><------>*dsize_ptr = evbuf->dsize;
<------><------>if (esize_ptr)
<------><------><------>*esize_ptr = evbuf->esize;
<------><------>pr_debug("success (dsize=%u, esize=%u)\n", evbuf->dsize,
<------><------><------> evbuf->esize);
<------><------>break;
<------>case 3:
<------><------>rc = -ENOENT;
<------><------>break;
<------>default:
<------><------>rc = -EIO;
<------><------>break;
 
<------>}
 
out:
<------>if (rc && rc != -ENOENT) {
<------><------>/* Provide some information about what went wrong */
<------><------>pr_warn("Store Data request failed (eq=%d, di=%d, "
<------><------><------>"response=0x%04x, flags=0x%02x, status=%d, rc=%d)\n",
<------><------><------>eq, di, sccb->hdr.response_code, evbuf->hdr.flags,
<------><------><------>evbuf->status, rc);
<------>}
 
out_remove:
<------>sclp_sd_listener_remove(&listener);
 
<------>return rc;
}
 
/**
 * sclp_sd_store_data() - Obtain data for specified Store Data entity
 * @result: Resulting data
 * @di: DI value associated with this entity
 *
 * Perform a series of Store Data requests to obtain the size and contents of
 * the specified Store Data entity.
 *
 * Return:
 *   %0:       Success - result is stored in @result. @result->data must be
 *	       released using vfree() after use.
 *   %-ENOENT: No data available for this entity
 *   %<0:      Other error
 */
static int sclp_sd_store_data(struct sclp_sd_data *result, u8 di)
{
<------>u32 dsize = 0, esize = 0;
<------>unsigned long page, asce = 0;
<------>void *data = NULL;
<------>int rc;
 
<------>page = __get_free_page(GFP_KERNEL | GFP_DMA);
<------>if (!page)
<------><------>return -ENOMEM;
 
<------>/* Get size */
<------>rc = sclp_sd_sync(page, SD_EQ_SIZE, di, 0, 0, &dsize, &esize);
<------>if (rc)
<------><------>goto out;
<------>if (dsize == 0)
<------><------>goto out_result;
 
<------>/* Allocate memory */
<------>data = vzalloc(array_size((size_t)dsize, PAGE_SIZE));
<------>if (!data) {
<------><------>rc = -ENOMEM;
<------><------>goto out;
<------>}
 
<------>/* Get translation table for buffer */
<------>asce = base_asce_alloc((unsigned long) data, dsize);
<------>if (!asce) {
<------><------>vfree(data);
<------><------>rc = -ENOMEM;
<------><------>goto out;
<------>}
 
<------>/* Get data */
<------>rc = sclp_sd_sync(page, SD_EQ_STORE_DATA, di, asce, (u64) data, &dsize,
<------><------><------>  &esize);
<------>if (rc) {
<------><------>/* Cancel running request if interrupted */
<------><------>if (rc == -ERESTARTSYS)
<------><------><------>sclp_sd_sync(page, SD_EQ_HALT, di, 0, 0, NULL, NULL);
<------><------>vfree(data);
<------><------>goto out;
<------>}
 
out_result:
<------>result->esize_bytes = (size_t) esize * PAGE_SIZE;
<------>result->dsize_bytes = (size_t) dsize * PAGE_SIZE;
<------>result->data = data;
 
out:
<------>base_asce_free(asce);
<------>free_page(page);
 
<------>return rc;
}
 
/**
 * sclp_sd_data_reset() - Reset Store Data result buffer
 * @data: Data buffer to reset
 *
 * Reset @data to initial state and release associated memory.
 */
static void sclp_sd_data_reset(struct sclp_sd_data *data)
{
<------>vfree(data->data);
<------>data->data = NULL;
<------>data->dsize_bytes = 0;
<------>data->esize_bytes = 0;
}
 
/**
 * sclp_sd_file_release() - Release function for sclp_sd_file object
 * @kobj: Kobject embedded in sclp_sd_file object
 */
static void sclp_sd_file_release(struct kobject *kobj)
{
<------>struct sclp_sd_file *sd_file = to_sd_file(kobj);
 
<------>sclp_sd_data_reset(&sd_file->data);
<------>kfree(sd_file);
}
 
/**
 * sclp_sd_file_update() - Update contents of sclp_sd_file object
 * @sd_file: Object to update
 *
 * Obtain the current version of data associated with the Store Data entity
 * @sd_file.
 *
 * On success, return %0 and generate a KOBJ_CHANGE event to indicate that the
 * data may have changed. Return non-zero otherwise.
 */
static int sclp_sd_file_update(struct sclp_sd_file *sd_file)
{
<------>const char *name = kobject_name(&sd_file->kobj);
<------>struct sclp_sd_data data;
<------>int rc;
 
<------>rc = sclp_sd_store_data(&data, sd_file->di);
<------>if (rc) {
<------><------>if (rc == -ENOENT) {
<------><------><------>pr_info("No data is available for the %s data entity\n",
<------><------><------><------> name);
<------><------>}
<------><------>return rc;
<------>}
 
<------>mutex_lock(&sd_file->data_mutex);
<------>sclp_sd_data_reset(&sd_file->data);
<------>sd_file->data = data;
<------>mutex_unlock(&sd_file->data_mutex);
 
<------>pr_info("A %zu-byte %s data entity was retrieved\n", data.dsize_bytes,
<------><------>name);
<------>kobject_uevent(&sd_file->kobj, KOBJ_CHANGE);
 
<------>return 0;
}
 
/**
 * sclp_sd_file_update_async() - Wrapper for asynchronous update call
 * @data: Object to update
 */
static void sclp_sd_file_update_async(void *data, async_cookie_t cookie)
{
<------>struct sclp_sd_file *sd_file = data;
 
<------>sclp_sd_file_update(sd_file);
}
 
/**
 * reload_store() - Store function for "reload" sysfs attribute
 * @kobj: Kobject of sclp_sd_file object
 *
 * Initiate a reload of the data associated with an sclp_sd_file object.
 */
static ssize_t reload_store(struct kobject *kobj, struct kobj_attribute *attr,
<------><------><------>    const char *buf, size_t count)
{
<------>struct sclp_sd_file *sd_file = to_sd_file(kobj);
 
<------>sclp_sd_file_update(sd_file);
 
<------>return count;
}
 
static struct kobj_attribute reload_attr = __ATTR_WO(reload);
 
static struct attribute *sclp_sd_file_default_attrs[] = {
<------>&reload_attr.attr,
<------>NULL,
};
 
static struct kobj_type sclp_sd_file_ktype = {
<------>.sysfs_ops = &kobj_sysfs_ops,
<------>.release = sclp_sd_file_release,
<------>.default_attrs = sclp_sd_file_default_attrs,
};
 
/**
 * data_read() - Read function for "read" sysfs attribute
 * @kobj: Kobject of sclp_sd_file object
 * @buffer: Target buffer
 * @off: Requested file offset
 * @size: Requested number of bytes
 *
 * Store the requested portion of the Store Data entity contents into the
 * specified buffer. Return the number of bytes stored on success, or %0
 * on EOF.
 */
static ssize_t data_read(struct file *file, struct kobject *kobj,
<------><------><------> struct bin_attribute *attr, char *buffer,
<------><------><------> loff_t off, size_t size)
{
<------>struct sclp_sd_file *sd_file = to_sd_file(kobj);
<------>size_t data_size;
<------>char *data;
 
<------>mutex_lock(&sd_file->data_mutex);
 
<------>data = sd_file->data.data;
<------>data_size = sd_file->data.dsize_bytes;
<------>if (!data || off >= data_size) {
<------><------>size = 0;
<------>} else {
<------><------>if (off + size > data_size)
<------><------><------>size = data_size - off;
<------><------>memcpy(buffer, data + off, size);
<------>}
 
<------>mutex_unlock(&sd_file->data_mutex);
 
<------>return size;
}
 
/**
 * sclp_sd_file_create() - Add a sysfs file representing a Store Data entity
 * @name: Name of file
 * @di: DI value associated with this entity
 *
 * Create a sysfs directory with the given @name located under
 *
 *   /sys/firmware/sclp_sd/
 *
 * The files in this directory can be used to access the contents of the Store
 * Data entity associated with @DI.
 *
 * Return pointer to resulting sclp_sd_file object on success, %NULL otherwise.
 * The object must be freed by calling kobject_put() on the embedded kobject
 * pointer after use.
 */
static __init struct sclp_sd_file *sclp_sd_file_create(const char *name, u8 di)
{
<------>struct sclp_sd_file *sd_file;
<------>int rc;
 
<------>sd_file = kzalloc(sizeof(*sd_file), GFP_KERNEL);
<------>if (!sd_file)
<------><------>return NULL;
<------>sd_file->di = di;
<------>mutex_init(&sd_file->data_mutex);
 
<------>/* Create kobject located under /sys/firmware/sclp_sd/ */
<------>sd_file->kobj.kset = sclp_sd_kset;
<------>rc = kobject_init_and_add(&sd_file->kobj, &sclp_sd_file_ktype, NULL,
<------><------><------><------>  "%s", name);
<------>if (rc) {
<------><------>kobject_put(&sd_file->kobj);
<------><------>return NULL;
<------>}
 
<------>sysfs_bin_attr_init(&sd_file->data_attr);
<------>sd_file->data_attr.attr.name = "data";
<------>sd_file->data_attr.attr.mode = 0444;
<------>sd_file->data_attr.read = data_read;
 
<------>rc = sysfs_create_bin_file(&sd_file->kobj, &sd_file->data_attr);
<------>if (rc) {
<------><------>kobject_put(&sd_file->kobj);
<------><------>return NULL;
<------>}
 
<------>/*
<------> * For completeness only - users interested in entity data should listen
<------> * for KOBJ_CHANGE instead.
<------> */
<------>kobject_uevent(&sd_file->kobj, KOBJ_ADD);
 
<------>/* Don't let a slow Store Data request delay further initialization */
<------>async_schedule(sclp_sd_file_update_async, sd_file);
 
<------>return sd_file;
}
 
/**
 * sclp_sd_init() - Initialize sclp_sd support and register sysfs files
 */
static __init int sclp_sd_init(void)
{
<------>int rc;
 
<------>rc = sclp_register(&sclp_sd_register);
<------>if (rc)
<------><------>return rc;
 
<------>/* Create kset named "sclp_sd" located under /sys/firmware/ */
<------>rc = -ENOMEM;
<------>sclp_sd_kset = kset_create_and_add("sclp_sd", NULL, firmware_kobj);
<------>if (!sclp_sd_kset)
<------><------>goto err_kset;
 
<------>rc = -EINVAL;
<------>config_file = sclp_sd_file_create("config", SD_DI_CONFIG);
<------>if (!config_file)
<------><------>goto err_config;
 
<------>return 0;
 
err_config:
<------>kset_unregister(sclp_sd_kset);
err_kset:
<------>sclp_unregister(&sclp_sd_register);
 
<------>return rc;
}
device_initcall(sclp_sd_init);