// SPDX-License-Identifier: MIT
/*
 * Copyright © 2019 Intel Corporation
 */

#include <linux/kernel.h>

#include "i915_debugfs_params.h"
#include "gt/intel_gt.h"
#include "gt/uc/intel_guc.h"
#include "i915_drv.h"
#include "i915_params.h"

#define MATCH_DEBUGFS_NODE_NAME(_file, _name) \
        (strcmp((_file)->f_path.dentry->d_name.name, (_name)) == 0)

#define GET_I915(i915, name, ptr)       \
        do {    \
                struct i915_params *params;     \
                params = container_of(((void *)(ptr)), typeof(*params), name);  \
                (i915) = container_of(params, typeof(*(i915)), params); \
        } while (0)

/* int param */
static int i915_param_int_show(struct seq_file *m, void *data)
{
        int *value = m->private;

        seq_printf(m, "%d\n", *value);

        return 0;
}

static int i915_param_int_open(struct inode *inode, struct file *file)
{
        return single_open(file, i915_param_int_show, inode->i_private);
}

static int notify_guc(struct drm_i915_private *i915)
{
        int ret = 0;

        if (intel_uc_uses_guc_submission(&i915->gt.uc))
                ret = intel_guc_global_policies_update(&i915->gt.uc.guc);

        return ret;
}

static ssize_t i915_param_int_write(struct file *file,
                                    const char __user *ubuf, size_t len,
                                    loff_t *offp)
{
        struct seq_file *m = file->private_data;
        int *value = m->private;
        int ret;

        ret = kstrtoint_from_user(ubuf, len, 0, value);
        if (ret) {
                /* support boolean values too */
                bool b;

                ret = kstrtobool_from_user(ubuf, len, &b);
                if (!ret)
                        *value = b;
        }

        return ret ?: len;
}

static const struct file_operations i915_param_int_fops = {
        .owner = THIS_MODULE,
        .open = i915_param_int_open,
        .read = seq_read,
        .write = i915_param_int_write,
        .llseek = default_llseek,
        .release = single_release,
};

static const struct file_operations i915_param_int_fops_ro = {
        .owner = THIS_MODULE,
        .open = i915_param_int_open,
        .read = seq_read,
        .llseek = default_llseek,
        .release = single_release,
};

/* unsigned int param */
static int i915_param_uint_show(struct seq_file *m, void *data)
{
        unsigned int *value = m->private;

        seq_printf(m, "%u\n", *value);

        return 0;
}

static int i915_param_uint_open(struct inode *inode, struct file *file)
{
        return single_open(file, i915_param_uint_show, inode->i_private);
}

static ssize_t i915_param_uint_write(struct file *file,
                                     const char __user *ubuf, size_t len,
                                     loff_t *offp)
{
        struct drm_i915_private *i915;
        struct seq_file *m = file->private_data;
        unsigned int *value = m->private;
        unsigned int old = *value;
        int ret;

        ret = kstrtouint_from_user(ubuf, len, 0, value);
        if (ret) {
                /* support boolean values too */
                bool b;

                ret = kstrtobool_from_user(ubuf, len, &b);
                if (!ret)
                        *value = b;
        }

        if (!ret && MATCH_DEBUGFS_NODE_NAME(file, "reset")) {
                GET_I915(i915, reset, value);

                ret = notify_guc(i915);
                if (ret)
                        *value = old;
        }

        return ret ?: len;
}

static const struct file_operations i915_param_uint_fops = {
        .owner = THIS_MODULE,
        .open = i915_param_uint_open,
        .read = seq_read,
        .write = i915_param_uint_write,
        .llseek = default_llseek,
        .release = single_release,
};

static const struct file_operations i915_param_uint_fops_ro = {
        .owner = THIS_MODULE,
        .open = i915_param_uint_open,
        .read = seq_read,
        .llseek = default_llseek,
        .release = single_release,
};

/* char * param */
static int i915_param_charp_show(struct seq_file *m, void *data)
{
        const char **s = m->private;

        seq_printf(m, "%s\n", *s);

        return 0;
}

static int i915_param_charp_open(struct inode *inode, struct file *file)
{
        return single_open(file, i915_param_charp_show, inode->i_private);
}

static ssize_t i915_param_charp_write(struct file *file,
                                      const char __user *ubuf, size_t len,
                                      loff_t *offp)
{
        struct seq_file *m = file->private_data;
        char **s = m->private;
        char *new, *old;

        old = *s;
        new = strndup_user(ubuf, PAGE_SIZE);
        if (IS_ERR(new)) {
                len = PTR_ERR(new);
                goto out;
        }

        *s = new;

        kfree(old);
out:
        return len;
}

static const struct file_operations i915_param_charp_fops = {
        .owner = THIS_MODULE,
        .open = i915_param_charp_open,
        .read = seq_read,
        .write = i915_param_charp_write,
        .llseek = default_llseek,
        .release = single_release,
};

static const struct file_operations i915_param_charp_fops_ro = {
        .owner = THIS_MODULE,
        .open = i915_param_charp_open,
        .read = seq_read,
        .llseek = default_llseek,
        .release = single_release,
};

#define RO(mode) (((mode) & 0222) == 0)

static struct dentry *
i915_debugfs_create_int(const char *name, umode_t mode,
                        struct dentry *parent, int *value)
{
        return debugfs_create_file_unsafe(name, mode, parent, value,
                                          RO(mode) ? &i915_param_int_fops_ro :
                                          &i915_param_int_fops);
}

static struct dentry *
i915_debugfs_create_uint(const char *name, umode_t mode,
                         struct dentry *parent, unsigned int *value)
{
        return debugfs_create_file_unsafe(name, mode, parent, value,
                                          RO(mode) ? &i915_param_uint_fops_ro :
                                          &i915_param_uint_fops);
}

static struct dentry *
i915_debugfs_create_charp(const char *name, umode_t mode,
                          struct dentry *parent, char **value)
{
        return debugfs_create_file(name, mode, parent, value,
                                   RO(mode) ? &i915_param_charp_fops_ro :
                                   &i915_param_charp_fops);
}

static __always_inline void
_i915_param_create_file(struct dentry *parent, const char *name,
                        const char *type, int mode, void *value)
{
        if (!mode)
                return;

        if (!__builtin_strcmp(type, "bool"))
                debugfs_create_bool(name, mode, parent, value);
        else if (!__builtin_strcmp(type, "int"))
                i915_debugfs_create_int(name, mode, parent, value);
        else if (!__builtin_strcmp(type, "unsigned int"))
                i915_debugfs_create_uint(name, mode, parent, value);
        else if (!__builtin_strcmp(type, "unsigned long"))
                debugfs_create_ulong(name, mode, parent, value);
        else if (!__builtin_strcmp(type, "char *"))
                i915_debugfs_create_charp(name, mode, parent, value);
        else
                WARN(1, "no debugfs fops defined for param type %s (i915.%s)\n",
                     type, name);
}

/* add a subdirectory with files for each i915 param */
struct dentry *i915_debugfs_params(struct drm_i915_private *i915)
{
        struct drm_minor *minor = i915->drm.primary;
        struct i915_params *params = &i915->params;
        struct dentry *dir;

        dir = debugfs_create_dir("i915_params", minor->debugfs_root);
        if (IS_ERR(dir))
                return dir;

        /*
         * Note: We could create files for params needing special handling
         * here. Set mode in params to 0 to skip the generic create file, or
         * just let the generic create file fail silently with -EEXIST.
         */

#define REGISTER(T, x, unused, mode, ...) _i915_param_create_file(dir, #x, #T, mode, &params->x);
        I915_PARAMS_FOR_EACH(REGISTER);
#undef REGISTER

        return dir;
}