/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * GSP vGPU-IO Driver - Debugfs Interface
 */

#include "gsp_core.h"
#include <linux/debugfs.h>
#include <linux/seq_file.h>

static int gsp_debugfs_vfs_show(struct seq_file *s, void *unused)
{
    struct gsp_device *gsp = s->private;
    struct gsp_vf *vf;
    
    seq_printf(s, "%-4s %-12s %-10s %-18s %-18s\n",
               "ID", "STATE", "REFCNT", "BAR1", "PAGE_TABLE");
    
    mutex_lock(&gsp->vf_lock);
    list_for_each_entry(vf, &gsp->vf_list, list) {
        seq_printf(s, "%-4u %-12d %-10d 0x%016llx-0x%016llx 0x%016llx-0x%016llx\n",
                   vf->id, vf->state, atomic_read(&vf->refcount),
                   vf->bar1_offset, vf->bar1_offset + vf->bar1_size,
                   vf->pt_base, vf->pt_base + vf->pt_size);
    }
    mutex_unlock(&gsp->vf_lock);
    
    return 0;
}

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

static const struct file_operations gsp_debugfs_vfs_fops = {
    .open = gsp_debugfs_vfs_open,
    .read = seq_read,
    .llseek = seq_lseek,
    .release = single_release,
};

static int gsp_debugfs_vf_show(struct seq_file *s, void *unused)
{
    struct gsp_vf *vf = s->private;
    struct gsp_wpr_region *rgn;
    
    seq_printf(s, "VF %u\n", vf->id);
    seq_printf(s, "  State:       %d\n", vf->state);
    seq_printf(s, "  Refcount:    %d\n", atomic_read(&vf->refcount));
    seq_printf(s, "  BAR1:        0x%llx - 0x%llx (size: 0x%llx)\n",
               vf->bar1_offset, vf->bar1_offset + vf->bar1_size, vf->bar1_size);
    seq_printf(s, "  Page Table:  0x%llx - 0x%llx (size: 0x%llx)\n",
               vf->pt_base, vf->pt_base + vf->pt_size, vf->pt_size);
    seq_printf(s, "  Cmd Buffer:  0x%llx - 0x%llx (size: 0x%llx)\n",
               vf->cmd_base, vf->cmd_base + vf->cmd_size, vf->cmd_size);
    seq_printf(s, "  BAR State:\n");
    seq_printf(s, "    Aperture:  0x%llx - 0x%llx\n",
               vf->bar_state.aperture_offset,
               vf->bar_state.aperture_offset + vf->bar_state.aperture_size);
    seq_printf(s, "    ForceAcc:  %s (VF: %u)\n",
               vf->bar_state.force_access ? "enabled" : "disabled",
               vf->bar_state.force_vf);
    seq_printf(s, "  WPR Regions:\n");
    
    mutex_lock(&vf->wpr_lock);
    list_for_each_entry(rgn, &vf->wpr_list, list) {
        seq_printf(s, "    [0x%llx, 0x%llx) flags=0x%x\n",
                   rgn->base, rgn->base + rgn->size, rgn->flags);
    }
    mutex_unlock(&vf->wpr_lock);
    
    if (vf->migration) {
        seq_printf(s, "  Migration:\n");
        seq_printf(s, "    State:     %d\n", vf->migration->state);
        seq_printf(s, "    Dst VF:    %llu\n", vf->migration->dst_vf);
        seq_printf(s, "    Token:     0x%llx\n", vf->migration->token);
        seq_printf(s, "    Progress:  %llu pages, %llu bytes\n",
                   vf->migration->progress.pages_transferred,
                   vf->migration->progress.bytes_transferred);
    }
    
    return 0;
}

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

static const struct file_operations gsp_debugfs_vf_fops = {
    .open = gsp_debugfs_vf_open,
    .read = seq_read,
    .llseek = seq_lseek,
    .release = single_release,
};

static int gsp_debugfs_rpc_show(struct seq_file *s, void *unused)
{
    struct gsp_device *gsp = s->private;
    
    seq_printf(s, "RPC Statistics:\n");
    seq_printf(s, "  Total:       %lld\n", atomic64_read(&gsp->rpc_total));
    seq_printf(s, "  Errors:      %lld\n", atomic64_read(&gsp->rpc_errors));
    seq_printf(s, "  BAR Traps:   %lld\n", atomic64_read(&gsp->bar_traps));
    seq_printf(s, "  WPR Events:  %lld\n", atomic64_read(&gsp->wpr_events));
    seq_printf(s, "  Migrations:  %lld\n", atomic64_read(&gsp->migrations));
    
    return 0;
}

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

static const struct file_operations gsp_debugfs_rpc_fops = {
    .open = gsp_debugfs_rpc_open,
    .read = seq_read,
    .llseek = seq_lseek,
    .release = single_release,
};

static int gsp_debugfs_bar_show(struct seq_file *s, void *unused)
{
    struct gsp_vf *vf = s->private;
    
    seq_printf(s, "VF %u BAR State:\n", vf->id);
    seq_printf(s, "  Aperture Offset:  0x%llx\n", vf->bar_state.aperture_offset);
    seq_printf(s, "  Aperture Size:    0x%llx\n", vf->bar_state.aperture_size);
    seq_printf(s, "  Force Access:     %s\n", vf->bar_state.force_access ? "enabled" : "disabled");
    seq_printf(s, "  Force VF:         %u\n", vf->bar_state.force_vf);
    seq_printf(s, "  Backing Store:    %p\n", vf->bar_state.backing_store);
    seq_printf(s, "  Backing Size:     0x%zx\n", vf->bar_state.backing_size);
    
    return 0;
}

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

static const struct file_operations gsp_debugfs_bar_fops = {
    .open = gsp_debugfs_bar_open,
    .read = seq_read,
    .llseek = seq_lseek,
    .release = single_release,
};

static int gsp_debugfs_wpr_show(struct seq_file *s, void *unused)
{
    struct gsp_vf *vf = s->private;
    struct gsp_wpr_region *rgn;
    
    seq_printf(s, "VF %u WPR Regions:\n", vf->id);
    
    mutex_lock(&vf->wpr_lock);
    list_for_each_entry(rgn, &vf->wpr_list, list) {
        seq_printf(s, "  [0x%llx, 0x%llx) size=0x%llx flags=0x%x\n",
                   rgn->base, rgn->base + rgn->size, rgn->size, rgn->flags);
    }
    mutex_unlock(&vf->wpr_lock);
    
    return 0;
}

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

static const struct file_operations gsp_debugfs_wpr_fops = {
    .open = gsp_debugfs_wpr_open,
    .read = seq_read,
    .llseek = seq_lseek,
    .release = single_release,
};

static int gsp_debugfs_migration_show(struct seq_file *s, void *unused)
{
    struct gsp_vf *vf = s->private;
    
    if (!vf->migration) {
        seq_printf(s, "No active migration\n");
        return 0;
    }
    
    seq_printf(s, "VF %u Migration:\n", vf->id);
    seq_printf(s, "  State:           %d\n", vf->migration->state);
    seq_printf(s, "  Destination VF:  %llu\n", vf->migration->dst_vf);
    seq_printf(s, "  Token:           0x%llx\n", vf->migration->token);
    seq_printf(s, "  Flags:           0x%x\n", vf->migration->flags);
    seq_printf(s, "  Pages Xfer:      %llu\n", vf->migration->progress.pages_transferred);
    seq_printf(s, "  Bytes Xfer:      %llu\n", vf->migration->progress.bytes_transferred);
    seq_printf(s, "  Dirty Pages:     %llu\n", vf->migration->progress.dirty_pages);
    seq_printf(s, "  Cancelled:       %s\n", vf->migration->cancelled ? "yes" : "no");
    
    return 0;
}

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

static const struct file_operations gsp_debugfs_migration_fops = {
    .open = gsp_debugfs_migration_open,
    .read = seq_read,
    .llseek = seq_lseek,
    .release = single_release,
};

/* VF Debugfs Directory Creation */
static void gsp_debugfs_vf_create(struct gsp_vf *vf)
{
    char name[16];
    struct dentry *vf_dir;
    
    snprintf(name, sizeof(name), "vf%u", vf->id);
    vf_dir = debugfs_create_dir(name, vf->gsp->debugfs_vfs_dir);
    if (!vf_dir)
        return;
    
    debugfs_create_file("status", 0444, vf_dir, vf, &gsp_debugfs_vf_fops);
    debugfs_create_file("bar", 0444, vf_dir, vf, &gsp_debugfs_bar_fops);
    debugfs_create_file("wpr", 0444, vf_dir, vf, &gsp_debugfs_wpr_fops);
    debugfs_create_file("migration", 0444, vf_dir, vf, &gsp_debugfs_migration_fops);
}

/* Main Debugfs Init */
int gsp_debugfs_init(struct gsp_device *gsp)
{
    gsp->debugfs_root = debugfs_create_dir("gsp-vgpu", NULL);
    if (!gsp->debugfs_root)
        return -ENOMEM;
    
    debugfs_create_file("vfs", 0444, gsp->debugfs_root, gsp, &gsp_debugfs_vfs_fops);
    debugfs_create_file("rpc", 0444, gsp->debugfs_root, gsp, &gsp_debugfs_rpc_fops);
    
    gsp->debugfs_vfs_dir = debugfs_create_dir("vfs", gsp->debugfs_root);
    if (!gsp->debugfs_vfs_dir) {
        debugfs_remove_recursive(gsp->debugfs_root);
        return -ENOMEM;
    }
    
    /* Create entries for existing VFs */
    mutex_lock(&gsp->vf_lock);
    struct gsp_vf *vf;
    list_for_each_entry(vf, &gsp->vf_list, list)
        gsp_debugfs_vf_create(vf);
    mutex_unlock(&gsp->vf_lock);
    
    return 0;
}

void gsp_debugfs_fini(struct gsp_device *gsp)
{
    if (gsp->debugfs_root)
        debugfs_remove_recursive(gsp->debugfs_root);
}

/* Export for VF creation/destruction */
void gsp_debugfs_vf_add(struct gsp_vf *vf)
{
    gsp_debugfs_vf_create(vf);
}

void gsp_debugfs_vf_remove(struct gsp_vf *vf)
{
    char name[16];
    snprintf(name, sizeof(name), "vf%u", vf->id);
    debugfs_remove_recursive(debugfs_lookup(name, vf->gsp->debugfs_vfs_dir));
}