// SPDX-License-Identifier: GPL-2.0-only
/* Copyright(c) 2022 Intel Corporation. */

#include <linux/cpu.h>
#include <linux/delay.h>
#include <linux/fs.h>
#include <linux/semaphore.h>
#include <linux/slab.h>

#include "ifs.h"

/*
 * Protects against simultaneous tests on multiple cores, or
 * reloading can file while a test is in progress
 */
static DEFINE_SEMAPHORE(ifs_sem, 1);

/*
 * The sysfs interface to check additional details of last test
 * cat /sys/devices/system/platform/ifs/details
 */
static ssize_t details_show(struct device *dev,
                            struct device_attribute *attr,
                            char *buf)
{
        struct ifs_data *ifsd = ifs_get_data(dev);

        return sysfs_emit(buf, "%#llx\n", ifsd->scan_details);
}

static DEVICE_ATTR_RO(details);

static const char * const status_msg[] = {
        [SCAN_NOT_TESTED] = "untested",
        [SCAN_TEST_PASS] = "pass",
        [SCAN_TEST_FAIL] = "fail"
};

/*
 * The sysfs interface to check the test status:
 * To check the status of last test
 * cat /sys/devices/platform/ifs/status
 */
static ssize_t status_show(struct device *dev,
                           struct device_attribute *attr,
                           char *buf)
{
        struct ifs_data *ifsd = ifs_get_data(dev);

        return sysfs_emit(buf, "%s\n", status_msg[ifsd->status]);
}

static DEVICE_ATTR_RO(status);

/*
 * The sysfs interface for single core testing
 * To start test, for example, cpu5
 * echo 5 > /sys/devices/platform/ifs/run_test
 * To check the result:
 * cat /sys/devices/platform/ifs/result
 * The sibling core gets tested at the same time.
 */
static ssize_t run_test_store(struct device *dev,
                              struct device_attribute *attr,
                              const char *buf, size_t count)
{
        unsigned int cpu;
        int rc;

        rc = kstrtouint(buf, 0, &cpu);
        if (rc < 0 || cpu >= nr_cpu_ids)
                return -EINVAL;

        if (down_interruptible(&ifs_sem))
                return -EINTR;

        rc = do_core_test(cpu, dev);

        up(&ifs_sem);

        return rc ? rc : count;
}

static DEVICE_ATTR_WO(run_test);

static ssize_t current_batch_store(struct device *dev,
                                   struct device_attribute *attr,
                                   const char *buf, size_t count)
{
        struct ifs_data *ifsd = ifs_get_data(dev);
        unsigned int cur_batch;
        int rc;

        rc = kstrtouint(buf, 0, &cur_batch);
        if (rc < 0 || cur_batch > 0xff)
                return -EINVAL;

        if (down_interruptible(&ifs_sem))
                return -EINTR;

        ifsd->cur_batch = cur_batch;

        rc = ifs_load_firmware(dev);

        up(&ifs_sem);

        return (rc == 0) ? count : rc;
}

static ssize_t current_batch_show(struct device *dev,
                                  struct device_attribute *attr, char *buf)
{
        struct ifs_data *ifsd = ifs_get_data(dev);

        if (!ifsd->loaded)
                return sysfs_emit(buf, "none\n");
        else
                return sysfs_emit(buf, "0x%02x\n", ifsd->cur_batch);
}

static DEVICE_ATTR_RW(current_batch);

/*
 * Display currently loaded IFS image version.
 */
static ssize_t image_version_show(struct device *dev,
                                  struct device_attribute *attr, char *buf)
{
        struct ifs_data *ifsd = ifs_get_data(dev);

        if (!ifsd->loaded)
                return sysfs_emit(buf, "%s\n", "none");
        else
                return sysfs_emit(buf, "%#x\n", ifsd->loaded_version);
}

static DEVICE_ATTR_RO(image_version);

/* global scan sysfs attributes */
struct attribute *plat_ifs_attrs[] = {
        &dev_attr_details.attr,
        &dev_attr_status.attr,
        &dev_attr_run_test.attr,
        &dev_attr_current_batch.attr,
        &dev_attr_image_version.attr,
        NULL
};

/* global array sysfs attributes */
struct attribute *plat_ifs_array_attrs[] = {
        &dev_attr_details.attr,
        &dev_attr_status.attr,
        &dev_attr_run_test.attr,
        NULL
};