--- /dev/null
+// 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((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);
projects / platform / kernel / linux-starfive.git / commitdiff