// SPDX-License-Identifier: GPL-2.0
/*
 *  Copyright IBM Corp. 2012,2015
 *
 *  Author(s):
 *    Jan Glauber <jang@linux.vnet.ibm.com>
 */

#define pr_fmt(fmt) "zpci: " fmt

#include <linux/kernel.h>
#include <linux/seq_file.h>
#include <linux/debugfs.h>
#include <linux/export.h>
#include <linux/pci.h>
#include <asm/debug.h>

#include <asm/pci_dma.h>

static struct dentry *debugfs_root;
debug_info_t *pci_debug_msg_id;
EXPORT_SYMBOL_GPL(pci_debug_msg_id);
debug_info_t *pci_debug_err_id;
EXPORT_SYMBOL_GPL(pci_debug_err_id);

static char *pci_common_names[] = {
        "Load operations",
        "Store operations",
        "Store block operations",
        "Refresh operations",
};

static char *pci_fmt0_names[] = {
        "DMA read bytes",
        "DMA write bytes",
};

static char *pci_fmt1_names[] = {
        "Received bytes",
        "Received packets",
        "Transmitted bytes",
        "Transmitted packets",
};

static char *pci_fmt2_names[] = {
        "Consumed work units",
        "Maximum work units",
};

static char *pci_fmt3_names[] = {
        "Transmitted bytes",
};

static char *pci_sw_names[] = {
        "Mapped pages",
        "Unmapped pages",
        "Global RPCITs",
        "Sync Map RPCITs",
        "Sync RPCITs",
};

static void pci_fmb_show(struct seq_file *m, char *name[], int length,
                         u64 *data)
{
        int i;

        for (i = 0; i < length; i++, data++)
                seq_printf(m, "%26s:\t%llu\n", name[i], *data);
}

static void pci_sw_counter_show(struct seq_file *m)
{
        struct zpci_dev *zdev = m->private;
        struct zpci_iommu_ctrs *ctrs;
        atomic64_t *counter;
        unsigned long flags;
        int i;

        spin_lock_irqsave(&zdev->dom_lock, flags);
        ctrs = zpci_get_iommu_ctrs(m->private);
        if (!ctrs)
                goto unlock;

        counter = &ctrs->mapped_pages;
        for (i = 0; i < ARRAY_SIZE(pci_sw_names); i++, counter++)
                seq_printf(m, "%26s:\t%llu\n", pci_sw_names[i],
                           atomic64_read(counter));
unlock:
        spin_unlock_irqrestore(&zdev->dom_lock, flags);
}

static int pci_perf_show(struct seq_file *m, void *v)
{
        struct zpci_dev *zdev = m->private;

        if (!zdev)
                return 0;

        mutex_lock(&zdev->fmb_lock);
        if (!zdev->fmb) {
                mutex_unlock(&zdev->fmb_lock);
                seq_puts(m, "FMB statistics disabled\n");
                return 0;
        }

        /* header */
        seq_printf(m, "Update interval: %u ms\n", zdev->fmb_update);
        seq_printf(m, "Samples: %u\n", zdev->fmb->samples);
        seq_printf(m, "Last update TOD: %Lx\n", zdev->fmb->last_update);

        pci_fmb_show(m, pci_common_names, ARRAY_SIZE(pci_common_names),
                     &zdev->fmb->ld_ops);

        switch (zdev->fmb->format) {
        case 0:
                if (!(zdev->fmb->fmt_ind & ZPCI_FMB_DMA_COUNTER_VALID))
                        break;
                pci_fmb_show(m, pci_fmt0_names, ARRAY_SIZE(pci_fmt0_names),
                             &zdev->fmb->fmt0.dma_rbytes);
                break;
        case 1:
                pci_fmb_show(m, pci_fmt1_names, ARRAY_SIZE(pci_fmt1_names),
                             &zdev->fmb->fmt1.rx_bytes);
                break;
        case 2:
                pci_fmb_show(m, pci_fmt2_names, ARRAY_SIZE(pci_fmt2_names),
                             &zdev->fmb->fmt2.consumed_work_units);
                break;
        case 3:
                pci_fmb_show(m, pci_fmt3_names, ARRAY_SIZE(pci_fmt3_names),
                             &zdev->fmb->fmt3.tx_bytes);
                break;
        default:
                seq_puts(m, "Unknown format\n");
        }

        pci_sw_counter_show(m);
        mutex_unlock(&zdev->fmb_lock);
        return 0;
}

static ssize_t pci_perf_seq_write(struct file *file, const char __user *ubuf,
                                  size_t count, loff_t *off)
{
        struct zpci_dev *zdev = ((struct seq_file *) file->private_data)->private;
        unsigned long val;
        int rc;

        if (!zdev)
                return 0;

        rc = kstrtoul_from_user(ubuf, count, 10, &val);
        if (rc)
                return rc;

        mutex_lock(&zdev->fmb_lock);
        switch (val) {
        case 0:
                rc = zpci_fmb_disable_device(zdev);
                break;
        case 1:
                rc = zpci_fmb_enable_device(zdev);
                break;
        }
        mutex_unlock(&zdev->fmb_lock);
        return rc ? rc : count;
}

static int pci_perf_seq_open(struct inode *inode, struct file *filp)
{
        return single_open(filp, pci_perf_show,
                           file_inode(filp)->i_private);
}

static const struct file_operations debugfs_pci_perf_fops = {
        .open    = pci_perf_seq_open,
        .read    = seq_read,
        .write   = pci_perf_seq_write,
        .llseek  = seq_lseek,
        .release = single_release,
};

void zpci_debug_init_device(struct zpci_dev *zdev, const char *name)
{
        zdev->debugfs_dev = debugfs_create_dir(name, debugfs_root);

        debugfs_create_file("statistics", S_IFREG | S_IRUGO | S_IWUSR,
                            zdev->debugfs_dev, zdev, &debugfs_pci_perf_fops);
}

void zpci_debug_exit_device(struct zpci_dev *zdev)
{
        debugfs_remove_recursive(zdev->debugfs_dev);
}

int __init zpci_debug_init(void)
{
        /* event trace buffer */
        pci_debug_msg_id = debug_register("pci_msg", 8, 1, 8 * sizeof(long));
        if (!pci_debug_msg_id)
                return -EINVAL;
        debug_register_view(pci_debug_msg_id, &debug_sprintf_view);
        debug_set_level(pci_debug_msg_id, 3);

        /* error log */
        pci_debug_err_id = debug_register("pci_error", 2, 1, 16);
        if (!pci_debug_err_id)
                return -EINVAL;
        debug_register_view(pci_debug_err_id, &debug_hex_ascii_view);
        debug_set_level(pci_debug_err_id, 3);

        debugfs_root = debugfs_create_dir("pci", NULL);
        return 0;
}

void zpci_debug_exit(void)
{
        debug_unregister(pci_debug_msg_id);
        debug_unregister(pci_debug_err_id);
        debugfs_remove(debugfs_root);
}