root/drivers/usb/host/uhci-debug.c
// SPDX-License-Identifier: GPL-2.0
/*
 * UHCI-specific debugging code. Invaluable when something
 * goes wrong, but don't get in my face.
 *
 * Kernel visible pointers are surrounded in []s and bus
 * visible pointers are surrounded in ()s
 *
 * (C) Copyright 1999 Linus Torvalds
 * (C) Copyright 1999-2001 Johannes Erdfelt
 */

#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/debugfs.h>
#include <asm/io.h>

#include "uhci-hcd.h"

#define EXTRA_SPACE     1024

static struct dentry *uhci_debugfs_root;

#ifdef CONFIG_DYNAMIC_DEBUG

/* Handle REALLY large printks so we don't overflow buffers */
static void lprintk(char *buf)
{
        char *p;

        /* Just write one line at a time */
        while (buf) {
                p = strchr(buf, '\n');
                if (p)
                        *p = 0;
                printk(KERN_DEBUG "%s\n", buf);
                buf = p;
                if (buf)
                        buf++;
        }
}

static int uhci_show_td(struct uhci_hcd *uhci, struct uhci_td *td, char *buf,
                        int len, int space)
{
        char *out = buf;
        char *spid;
        u32 status, token;

        status = td_status(uhci, td);
        out += sprintf(out, "%*s[%p] link (%08x) ", space, "", td,
                hc32_to_cpu(uhci, td->link));
        out += sprintf(out, "e%d %s%s%s%s%s%s%s%s%s%sLength=%x ",
                ((status >> 27) & 3),
                (status & TD_CTRL_SPD) ?      "SPD " : "",
                (status & TD_CTRL_LS) ?       "LS " : "",
                (status & TD_CTRL_IOC) ?      "IOC " : "",
                (status & TD_CTRL_ACTIVE) ?   "Active " : "",
                (status & TD_CTRL_STALLED) ?  "Stalled " : "",
                (status & TD_CTRL_DBUFERR) ?  "DataBufErr " : "",
                (status & TD_CTRL_BABBLE) ?   "Babble " : "",
                (status & TD_CTRL_NAK) ?      "NAK " : "",
                (status & TD_CTRL_CRCTIMEO) ? "CRC/Timeo " : "",
                (status & TD_CTRL_BITSTUFF) ? "BitStuff " : "",
                status & 0x7ff);
        if (out - buf > len)
                goto done;

        token = td_token(uhci, td);
        switch (uhci_packetid(token)) {
                case USB_PID_SETUP:
                        spid = "SETUP";
                        break;
                case USB_PID_OUT:
                        spid = "OUT";
                        break;
                case USB_PID_IN:
                        spid = "IN";
                        break;
                default:
                        spid = "?";
                        break;
        }

        out += sprintf(out, "MaxLen=%x DT%d EndPt=%x Dev=%x, PID=%x(%s) ",
                token >> 21,
                ((token >> 19) & 1),
                (token >> 15) & 15,
                (token >> 8) & 127,
                (token & 0xff),
                spid);
        out += sprintf(out, "(buf=%08x)\n", hc32_to_cpu(uhci, td->buffer));

done:
        if (out - buf > len)
                out += sprintf(out, " ...\n");
        return out - buf;
}

static int uhci_show_urbp(struct uhci_hcd *uhci, struct urb_priv *urbp,
                        char *buf, int len, int space)
{
        char *out = buf;
        struct uhci_td *td;
        int i, nactive, ninactive;
        char *ptype;


        out += sprintf(out, "urb_priv [%p] ", urbp);
        out += sprintf(out, "urb [%p] ", urbp->urb);
        out += sprintf(out, "qh [%p] ", urbp->qh);
        out += sprintf(out, "Dev=%d ", usb_pipedevice(urbp->urb->pipe));
        out += sprintf(out, "EP=%x(%s) ", usb_pipeendpoint(urbp->urb->pipe),
                        (usb_pipein(urbp->urb->pipe) ? "IN" : "OUT"));
        if (out - buf > len)
                goto done;

        switch (usb_pipetype(urbp->urb->pipe)) {
        case PIPE_ISOCHRONOUS: ptype = "ISO"; break;
        case PIPE_INTERRUPT: ptype = "INT"; break;
        case PIPE_BULK: ptype = "BLK"; break;
        default:
        case PIPE_CONTROL: ptype = "CTL"; break;
        }

        out += sprintf(out, "%s%s", ptype, (urbp->fsbr ? " FSBR" : ""));
        out += sprintf(out, " Actlen=%d%s", urbp->urb->actual_length,
                        (urbp->qh->type == USB_ENDPOINT_XFER_CONTROL ?
                                "-8" : ""));

        if (urbp->urb->unlinked)
                out += sprintf(out, " Unlinked=%d", urbp->urb->unlinked);
        out += sprintf(out, "\n");

        if (out - buf > len)
                goto done;

        i = nactive = ninactive = 0;
        list_for_each_entry(td, &urbp->td_list, list) {
                if (urbp->qh->type != USB_ENDPOINT_XFER_ISOC &&
                                (++i <= 10 || debug > 2)) {
                        out += sprintf(out, "%*s%d: ", space + 2, "", i);
                        out += uhci_show_td(uhci, td, out,
                                        len - (out - buf), 0);
                        if (out - buf > len)
                                goto tail;
                } else {
                        if (td_status(uhci, td) & TD_CTRL_ACTIVE)
                                ++nactive;
                        else
                                ++ninactive;
                }
        }
        if (nactive + ninactive > 0)
                out += sprintf(out,
                                "%*s[skipped %d inactive and %d active TDs]\n",
                                space, "", ninactive, nactive);
done:
        if (out - buf > len)
                out += sprintf(out, " ...\n");
tail:
        return out - buf;
}

static int uhci_show_qh(struct uhci_hcd *uhci,
                struct uhci_qh *qh, char *buf, int len, int space)
{
        char *out = buf;
        int i, nurbs;
        __hc32 element = qh_element(qh);
        char *qtype;

        switch (qh->type) {
        case USB_ENDPOINT_XFER_ISOC: qtype = "ISO"; break;
        case USB_ENDPOINT_XFER_INT: qtype = "INT"; break;
        case USB_ENDPOINT_XFER_BULK: qtype = "BLK"; break;
        case USB_ENDPOINT_XFER_CONTROL: qtype = "CTL"; break;
        default: qtype = "Skel" ; break;
        }

        out += sprintf(out, "%*s[%p] %s QH link (%08x) element (%08x)\n",
                        space, "", qh, qtype,
                        hc32_to_cpu(uhci, qh->link),
                        hc32_to_cpu(uhci, element));
        if (qh->type == USB_ENDPOINT_XFER_ISOC)
                out += sprintf(out,
                                "%*s    period %d phase %d load %d us, frame %x desc [%p]\n",
                                space, "", qh->period, qh->phase, qh->load,
                                qh->iso_frame, qh->iso_packet_desc);
        else if (qh->type == USB_ENDPOINT_XFER_INT)
                out += sprintf(out, "%*s    period %d phase %d load %d us\n",
                                space, "", qh->period, qh->phase, qh->load);
        if (out - buf > len)
                goto done;

        if (element & UHCI_PTR_QH(uhci))
                out += sprintf(out, "%*s  Element points to QH (bug?)\n", space, "");

        if (element & UHCI_PTR_DEPTH(uhci))
                out += sprintf(out, "%*s  Depth traverse\n", space, "");

        if (element & cpu_to_hc32(uhci, 8))
                out += sprintf(out, "%*s  Bit 3 set (bug?)\n", space, "");

        if (!(element & ~(UHCI_PTR_QH(uhci) | UHCI_PTR_DEPTH(uhci))))
                out += sprintf(out, "%*s  Element is NULL (bug?)\n", space, "");

        if (out - buf > len)
                goto done;

        if (list_empty(&qh->queue)) {
                out += sprintf(out, "%*s  queue is empty\n", space, "");
                if (qh == uhci->skel_async_qh) {
                        out += uhci_show_td(uhci, uhci->term_td, out,
                                        len - (out - buf), 0);
                        if (out - buf > len)
                                goto tail;
                }
        } else {
                struct urb_priv *urbp = list_entry(qh->queue.next,
                                struct urb_priv, node);
                struct uhci_td *td = list_entry(urbp->td_list.next,
                                struct uhci_td, list);

                if (element != LINK_TO_TD(uhci, td))
                        out += sprintf(out, "%*s Element != First TD\n",
                                        space, "");
                i = nurbs = 0;
                list_for_each_entry(urbp, &qh->queue, node) {
                        if (++i <= 10) {
                                out += uhci_show_urbp(uhci, urbp, out,
                                                len - (out - buf), space + 2);
                                if (out - buf > len)
                                        goto tail;
                        }
                        else
                                ++nurbs;
                }
                if (nurbs > 0)
                        out += sprintf(out, "%*s Skipped %d URBs\n",
                                        space, "", nurbs);
        }

        if (out - buf > len)
                goto done;

        if (qh->dummy_td) {
                out += sprintf(out, "%*s  Dummy TD\n", space, "");
                out += uhci_show_td(uhci, qh->dummy_td, out,
                                len - (out - buf), 0);
                if (out - buf > len)
                        goto tail;
        }

done:
        if (out - buf > len)
                out += sprintf(out, " ...\n");
tail:
        return out - buf;
}

static int uhci_show_sc(int port, unsigned short status, char *buf)
{
        return sprintf(buf, "  stat%d     =     %04x  %s%s%s%s%s%s%s%s%s%s\n",
                port,
                status,
                (status & USBPORTSC_SUSP) ?     " Suspend" : "",
                (status & USBPORTSC_OCC) ?      " OverCurrentChange" : "",
                (status & USBPORTSC_OC) ?       " OverCurrent" : "",
                (status & USBPORTSC_PR) ?       " Reset" : "",
                (status & USBPORTSC_LSDA) ?     " LowSpeed" : "",
                (status & USBPORTSC_RD) ?       " ResumeDetect" : "",
                (status & USBPORTSC_PEC) ?      " EnableChange" : "",
                (status & USBPORTSC_PE) ?       " Enabled" : "",
                (status & USBPORTSC_CSC) ?      " ConnectChange" : "",
                (status & USBPORTSC_CCS) ?      " Connected" : "");
}

static int uhci_show_root_hub_state(struct uhci_hcd *uhci, char *buf)
{
        char *rh_state;

        switch (uhci->rh_state) {
            case UHCI_RH_RESET:
                rh_state = "reset";             break;
            case UHCI_RH_SUSPENDED:
                rh_state = "suspended";         break;
            case UHCI_RH_AUTO_STOPPED:
                rh_state = "auto-stopped";      break;
            case UHCI_RH_RESUMING:
                rh_state = "resuming";          break;
            case UHCI_RH_SUSPENDING:
                rh_state = "suspending";        break;
            case UHCI_RH_RUNNING:
                rh_state = "running";           break;
            case UHCI_RH_RUNNING_NODEVS:
                rh_state = "running, no devs";  break;
            default:
                rh_state = "?";                 break;
        }
        return sprintf(buf, "Root-hub state: %s   FSBR: %d\n",
                        rh_state, uhci->fsbr_is_on);
}

static int uhci_show_status(struct uhci_hcd *uhci, char *buf, int len)
{
        char *out = buf;
        unsigned short usbcmd, usbstat, usbint, usbfrnum;
        unsigned int flbaseadd;
        unsigned char sof;
        unsigned short portsc1, portsc2;


        usbcmd    = uhci_readw(uhci, USBCMD);
        usbstat   = uhci_readw(uhci, USBSTS);
        usbint    = uhci_readw(uhci, USBINTR);
        usbfrnum  = uhci_readw(uhci, USBFRNUM);
        flbaseadd = uhci_readl(uhci, USBFLBASEADD);
        sof       = uhci_readb(uhci, USBSOF);
        portsc1   = uhci_readw(uhci, USBPORTSC1);
        portsc2   = uhci_readw(uhci, USBPORTSC2);

        out += sprintf(out, "  usbcmd    =     %04x   %s%s%s%s%s%s%s%s\n",
                usbcmd,
                (usbcmd & USBCMD_MAXP) ?    "Maxp64 " : "Maxp32 ",
                (usbcmd & USBCMD_CF) ?      "CF " : "",
                (usbcmd & USBCMD_SWDBG) ?   "SWDBG " : "",
                (usbcmd & USBCMD_FGR) ?     "FGR " : "",
                (usbcmd & USBCMD_EGSM) ?    "EGSM " : "",
                (usbcmd & USBCMD_GRESET) ?  "GRESET " : "",
                (usbcmd & USBCMD_HCRESET) ? "HCRESET " : "",
                (usbcmd & USBCMD_RS) ?      "RS " : "");
        if (out - buf > len)
                goto done;

        out += sprintf(out, "  usbstat   =     %04x   %s%s%s%s%s%s\n",
                usbstat,
                (usbstat & USBSTS_HCH) ?    "HCHalted " : "",
                (usbstat & USBSTS_HCPE) ?   "HostControllerProcessError " : "",
                (usbstat & USBSTS_HSE) ?    "HostSystemError " : "",
                (usbstat & USBSTS_RD) ?     "ResumeDetect " : "",
                (usbstat & USBSTS_ERROR) ?  "USBError " : "",
                (usbstat & USBSTS_USBINT) ? "USBINT " : "");
        if (out - buf > len)
                goto done;

        out += sprintf(out, "  usbint    =     %04x\n", usbint);
        out += sprintf(out, "  usbfrnum  =   (%d)%03x\n", (usbfrnum >> 10) & 1,
                0xfff & (4*(unsigned int)usbfrnum));
        out += sprintf(out, "  flbaseadd = %08x\n", flbaseadd);
        out += sprintf(out, "  sof       =       %02x\n", sof);
        if (out - buf > len)
                goto done;

        out += uhci_show_sc(1, portsc1, out);
        if (out - buf > len)
                goto done;

        out += uhci_show_sc(2, portsc2, out);
        if (out - buf > len)
                goto done;

        out += sprintf(out,
                        "Most recent frame: %x (%d)   Last ISO frame: %x (%d)\n",
                        uhci->frame_number, uhci->frame_number & 1023,
                        uhci->last_iso_frame, uhci->last_iso_frame & 1023);

done:
        if (out - buf > len)
                out += sprintf(out, " ...\n");
        return out - buf;
}

static int uhci_sprint_schedule(struct uhci_hcd *uhci, char *buf, int len)
{
        char *out = buf;
        int i, j;
        struct uhci_qh *qh;
        struct uhci_td *td;
        struct list_head *tmp, *head;
        int nframes, nerrs;
        __hc32 link;
        __hc32 fsbr_link;

        static const char * const qh_names[] = {
                "unlink", "iso", "int128", "int64", "int32", "int16",
                "int8", "int4", "int2", "async", "term"
        };

        out += uhci_show_root_hub_state(uhci, out);
        if (out - buf > len)
                goto done;
        out += sprintf(out, "HC status\n");
        out += uhci_show_status(uhci, out, len - (out - buf));
        if (out - buf > len)
                goto tail;

        out += sprintf(out, "Periodic load table\n");
        for (i = 0; i < MAX_PHASE; ++i) {
                out += sprintf(out, "\t%d", uhci->load[i]);
                if (i % 8 == 7)
                        *out++ = '\n';
        }
        out += sprintf(out, "Total: %d, #INT: %d, #ISO: %d\n",
                        uhci->total_load,
                        uhci_to_hcd(uhci)->self.bandwidth_int_reqs,
                        uhci_to_hcd(uhci)->self.bandwidth_isoc_reqs);
        if (debug <= 1)
                goto tail;

        out += sprintf(out, "Frame List\n");
        nframes = 10;
        nerrs = 0;
        for (i = 0; i < UHCI_NUMFRAMES; ++i) {
                __hc32 qh_dma;

                if (out - buf > len)
                        goto done;
                j = 0;
                td = uhci->frame_cpu[i];
                link = uhci->frame[i];
                if (!td)
                        goto check_link;

                if (nframes > 0) {
                        out += sprintf(out, "- Frame %d -> (%08x)\n",
                                        i, hc32_to_cpu(uhci, link));
                        j = 1;
                }

                head = &td->fl_list;
                tmp = head;
                do {
                        td = list_entry(tmp, struct uhci_td, fl_list);
                        tmp = tmp->next;
                        if (link != LINK_TO_TD(uhci, td)) {
                                if (nframes > 0) {
                                        out += sprintf(out,
                                                "    link does not match list entry!\n");
                                        if (out - buf > len)
                                                goto done;
                                } else
                                        ++nerrs;
                        }
                        if (nframes > 0) {
                                out += uhci_show_td(uhci, td, out,
                                                len - (out - buf), 4);
                                if (out - buf > len)
                                        goto tail;
                        }
                        link = td->link;
                } while (tmp != head);

check_link:
                qh_dma = uhci_frame_skel_link(uhci, i);
                if (link != qh_dma) {
                        if (nframes > 0) {
                                if (!j) {
                                        out += sprintf(out,
                                                "- Frame %d -> (%08x)\n",
                                                i, hc32_to_cpu(uhci, link));
                                        j = 1;
                                }
                                out += sprintf(out,
                                        "   link does not match QH (%08x)!\n",
                                        hc32_to_cpu(uhci, qh_dma));
                                if (out - buf > len)
                                        goto done;
                        } else
                                ++nerrs;
                }
                nframes -= j;
        }
        if (nerrs > 0)
                out += sprintf(out, "Skipped %d bad links\n", nerrs);

        out += sprintf(out, "Skeleton QHs\n");

        if (out - buf > len)
                goto done;

        fsbr_link = 0;
        for (i = 0; i < UHCI_NUM_SKELQH; ++i) {
                int cnt = 0;

                qh = uhci->skelqh[i];
                out += sprintf(out, "- skel_%s_qh\n", qh_names[i]);
                out += uhci_show_qh(uhci, qh, out, len - (out - buf), 4);
                if (out - buf > len)
                        goto tail;

                /* Last QH is the Terminating QH, it's different */
                if (i == SKEL_TERM) {
                        if (qh_element(qh) != LINK_TO_TD(uhci, uhci->term_td)) {
                                out += sprintf(out,
                                        "    skel_term_qh element is not set to term_td!\n");
                                if (out - buf > len)
                                        goto done;
                        }
                        link = fsbr_link;
                        if (!link)
                                link = LINK_TO_QH(uhci, uhci->skel_term_qh);
                        goto check_qh_link;
                }

                head = &qh->node;
                tmp = head->next;

                while (tmp != head) {
                        qh = list_entry(tmp, struct uhci_qh, node);
                        tmp = tmp->next;
                        if (++cnt <= 10) {
                                out += uhci_show_qh(uhci, qh, out,
                                                len - (out - buf), 4);
                                if (out - buf > len)
                                        goto tail;
                        }
                        if (!fsbr_link && qh->skel >= SKEL_FSBR)
                                fsbr_link = LINK_TO_QH(uhci, qh);
                }
                if ((cnt -= 10) > 0)
                        out += sprintf(out, "    Skipped %d QHs\n", cnt);

                link = UHCI_PTR_TERM(uhci);
                if (i <= SKEL_ISO)
                        ;
                else if (i < SKEL_ASYNC)
                        link = LINK_TO_QH(uhci, uhci->skel_async_qh);
                else if (!uhci->fsbr_is_on)
                        ;
                else
                        link = LINK_TO_QH(uhci, uhci->skel_term_qh);
check_qh_link:
                if (qh->link != link)
                        out += sprintf(out,
                                "    last QH not linked to next skeleton!\n");

                if (out - buf > len)
                        goto done;
        }

done:
        if (out - buf > len)
                out += sprintf(out, " ...\n");
tail:
        return out - buf;
}

#ifdef CONFIG_DEBUG_FS

#define MAX_OUTPUT      (64 * 1024)

struct uhci_debug {
        int size;
        char *data;
};

static int uhci_debug_open(struct inode *inode, struct file *file)
{
        struct uhci_hcd *uhci = inode->i_private;
        struct uhci_debug *up;
        unsigned long flags;

        up = kmalloc_obj(*up);
        if (!up)
                return -ENOMEM;

        up->data = kmalloc(MAX_OUTPUT, GFP_KERNEL);
        if (!up->data) {
                kfree(up);
                return -ENOMEM;
        }

        up->size = 0;
        spin_lock_irqsave(&uhci->lock, flags);
        if (uhci->is_initialized)
                up->size = uhci_sprint_schedule(uhci, up->data,
                                        MAX_OUTPUT - EXTRA_SPACE);
        spin_unlock_irqrestore(&uhci->lock, flags);

        file->private_data = up;

        return 0;
}

static loff_t uhci_debug_lseek(struct file *file, loff_t off, int whence)
{
        struct uhci_debug *up = file->private_data;
        return no_seek_end_llseek_size(file, off, whence, up->size);
}

static ssize_t uhci_debug_read(struct file *file, char __user *buf,
                                size_t nbytes, loff_t *ppos)
{
        struct uhci_debug *up = file->private_data;
        return simple_read_from_buffer(buf, nbytes, ppos, up->data, up->size);
}

static int uhci_debug_release(struct inode *inode, struct file *file)
{
        struct uhci_debug *up = file->private_data;

        kfree(up->data);
        kfree(up);

        return 0;
}

static const struct file_operations uhci_debug_operations = {
        .owner =        THIS_MODULE,
        .open =         uhci_debug_open,
        .llseek =       uhci_debug_lseek,
        .read =         uhci_debug_read,
        .release =      uhci_debug_release,
};
#define UHCI_DEBUG_OPS

#endif  /* CONFIG_DEBUG_FS */

#else   /* CONFIG_DYNAMIC_DEBUG*/

static inline void lprintk(char *buf)
{}

static inline int uhci_show_qh(struct uhci_hcd *uhci,
                struct uhci_qh *qh, char *buf, int len, int space)
{
        return 0;
}

static inline int uhci_sprint_schedule(struct uhci_hcd *uhci,
                char *buf, int len)
{
        return 0;
}

#endif