Quelle  hvc_opal.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0+
/*
 * opal driver interface to hvc_console.c
 *
 * Copyright 2011 Benjamin Herrenschmidt <benh@kernel.crashing.org>, IBM Corp.
 */

#undef DEBUG

#include <linux/types.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/console.h>
#include <linux/of.h>
#include <linux/of_irq.h>
#include <linux/platform_device.h>
#include <linux/export.h>
#include <linux/interrupt.h>

#include <asm/hvconsole.h>
#include <asm/firmware.h>
#include <asm/hvsi.h>
#include <asm/udbg.h>
#include <asm/opal.h>

#include "hvc_console.h"

static const char hvc_opal_name[] = "hvc_opal";

static const struct of_device_id hvc_opal_match[] = {
 { .name = "serial", .compatible = "ibm,opal-console-raw" },
 { .name = "serial", .compatible = "ibm,opal-console-hvsi" },
 { },
};

typedef enum hv_protocol {
 HV_PROTOCOL_RAW,
 HV_PROTOCOL_HVSI
} hv_protocol_t;

struct hvc_opal_priv {
 hv_protocol_t  proto; /* Raw data or HVSI packets */
 struct hvsi_priv hvsi; /* HVSI specific data */
};
static struct hvc_opal_priv *hvc_opal_privs[MAX_NR_HVC_CONSOLES];

/* For early boot console */
static struct hvc_opal_priv hvc_opal_boot_priv;
static u32 hvc_opal_boot_termno;

static const struct hv_ops hvc_opal_raw_ops = {
 .get_chars = opal_get_chars,
 .put_chars = opal_put_chars,
 .flush = opal_flush_chars,
 .notifier_add = notifier_add_irq,
 .notifier_del = notifier_del_irq,
 .notifier_hangup = notifier_hangup_irq,
};

static ssize_t hvc_opal_hvsi_get_chars(uint32_t vtermno, u8 *buf, size_t count)
{
 struct hvc_opal_priv *pv = hvc_opal_privs[vtermno];

 if (WARN_ON(!pv))
  return -ENODEV;

 return hvsilib_get_chars(&pv->hvsi, buf, count);
}

static ssize_t hvc_opal_hvsi_put_chars(uint32_t vtermno, const u8 *buf,
           size_t count)
{
 struct hvc_opal_priv *pv = hvc_opal_privs[vtermno];

 if (WARN_ON(!pv))
  return -ENODEV;

 return hvsilib_put_chars(&pv->hvsi, buf, count);
}

static int hvc_opal_hvsi_open(struct hvc_struct *hp, int data)
{
 struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
 int rc;

 pr_devel("HVSI@%x: do open !\n", hp->vtermno);

 rc = notifier_add_irq(hp, data);
 if (rc)
  return rc;

 return hvsilib_open(&pv->hvsi, hp);
}

static void hvc_opal_hvsi_close(struct hvc_struct *hp, int data)
{
 struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];

 pr_devel("HVSI@%x: do close !\n", hp->vtermno);

 hvsilib_close(&pv->hvsi, hp);

 notifier_del_irq(hp, data);
}

static void hvc_opal_hvsi_hangup(struct hvc_struct *hp, int data)
{
 struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];

 pr_devel("HVSI@%x: do hangup !\n", hp->vtermno);

 hvsilib_close(&pv->hvsi, hp);

 notifier_hangup_irq(hp, data);
}

static int hvc_opal_hvsi_tiocmget(struct hvc_struct *hp)
{
 struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];

 if (!pv)
  return -EINVAL;
 return pv->hvsi.mctrl;
}

static int hvc_opal_hvsi_tiocmset(struct hvc_struct *hp, unsigned int set,
    unsigned int clear)
{
 struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];

 pr_devel("HVSI@%x: Set modem control, set=%x,clr=%x\n",
   hp->vtermno, set, clear);

 if (set & TIOCM_DTR)
  hvsilib_write_mctrl(&pv->hvsi, 1);
 else if (clear & TIOCM_DTR)
  hvsilib_write_mctrl(&pv->hvsi, 0);

 return 0;
}

static const struct hv_ops hvc_opal_hvsi_ops = {
 .get_chars = hvc_opal_hvsi_get_chars,
 .put_chars = hvc_opal_hvsi_put_chars,
 .flush = opal_flush_chars,
 .notifier_add = hvc_opal_hvsi_open,
 .notifier_del = hvc_opal_hvsi_close,
 .notifier_hangup = hvc_opal_hvsi_hangup,
 .tiocmget = hvc_opal_hvsi_tiocmget,
 .tiocmset = hvc_opal_hvsi_tiocmset,
};

static int hvc_opal_probe(struct platform_device *dev)
{
 const struct hv_ops *ops;
 struct hvc_struct *hp;
 struct hvc_opal_priv *pv;
 hv_protocol_t proto;
 unsigned int termno, irq, boot = 0;
 const __be32 *reg;

 if (of_device_is_compatible(dev->dev.of_node, "ibm,opal-console-raw")) {
  proto = HV_PROTOCOL_RAW;
  ops = &hvc_opal_raw_ops;
 } else if (of_device_is_compatible(dev->dev.of_node,
        "ibm,opal-console-hvsi")) {
  proto = HV_PROTOCOL_HVSI;
  ops = &hvc_opal_hvsi_ops;
 } else {
  pr_err("hvc_opal: Unknown protocol for %pOF\n",
         dev->dev.of_node);
  return -ENXIO;
 }

 reg = of_get_property(dev->dev.of_node, "reg", NULL);
 termno = reg ? be32_to_cpup(reg) : 0;

 /* Is it our boot one ? */
 if (hvc_opal_privs[termno] == &hvc_opal_boot_priv) {
  pv = hvc_opal_privs[termno];
  boot = 1;
 } else if (hvc_opal_privs[termno] == NULL) {
  pv = kzalloc(sizeof(struct hvc_opal_priv), GFP_KERNEL);
  if (!pv)
   return -ENOMEM;
  pv->proto = proto;
  hvc_opal_privs[termno] = pv;
  if (proto == HV_PROTOCOL_HVSI) {
   /*
 * We want put_chars to be atomic to avoid mangling of
 * hvsi packets.
 */
   hvsilib_init(&pv->hvsi,
         opal_get_chars, opal_put_chars_atomic,
         termno, 0);
  }

  /* Instanciate now to establish a mapping index==vtermno */
  hvc_instantiate(termno, termno, ops);
 } else {
  pr_err("hvc_opal: Device %pOF has duplicate terminal number #%d\n",
         dev->dev.of_node, termno);
  return -ENXIO;
 }

 pr_info("hvc%d: %s protocol on %pOF%s\n", termno,
  proto == HV_PROTOCOL_RAW ? "raw" : "hvsi",
  dev->dev.of_node,
  boot ? " (boot console)" : "");

 irq = irq_of_parse_and_map(dev->dev.of_node, 0);
 if (!irq) {
  pr_info("hvc%d: No interrupts property, using OPAL event\n",
    termno);
  irq = opal_event_request(ilog2(OPAL_EVENT_CONSOLE_INPUT));
 }

 if (!irq) {
  pr_err("hvc_opal: Unable to map interrupt for device %pOF\n",
   dev->dev.of_node);
  return irq;
 }

 hp = hvc_alloc(termno, irq, ops, MAX_VIO_PUT_CHARS);
 if (IS_ERR(hp))
  return PTR_ERR(hp);

 /* hvc consoles on powernv may need to share a single irq */
 hp->flags = IRQF_SHARED;
 dev_set_drvdata(&dev->dev, hp);

 return 0;
}

static void hvc_opal_remove(struct platform_device *dev)
{
 struct hvc_struct *hp = dev_get_drvdata(&dev->dev);
 int termno;

 termno = hp->vtermno;
 hvc_remove(hp);
 if (hvc_opal_privs[termno] != &hvc_opal_boot_priv)
  kfree(hvc_opal_privs[termno]);
 hvc_opal_privs[termno] = NULL;
}

static struct platform_driver hvc_opal_driver = {
 .probe  = hvc_opal_probe,
 .remove  = hvc_opal_remove,
 .driver  = {
  .name = hvc_opal_name,
  .of_match_table = hvc_opal_match,
 }
};

static int __init hvc_opal_init(void)
{
 if (!firmware_has_feature(FW_FEATURE_OPAL))
  return -ENODEV;

 /* Register as a vio device to receive callbacks */
 return platform_driver_register(&hvc_opal_driver);
}
device_initcall(hvc_opal_init);

static void udbg_opal_putc(char c)
{
 unsigned int termno = hvc_opal_boot_termno;
 int count = -1;

 if (c == '\n')
  udbg_opal_putc('\r');

 do {
  switch(hvc_opal_boot_priv.proto) {
  case HV_PROTOCOL_RAW:
   count = opal_put_chars(termno, &c, 1);
   break;
  case HV_PROTOCOL_HVSI:
   count = hvc_opal_hvsi_put_chars(termno, &c, 1);
   break;
  }

  /* This is needed for the cosole to flush
 * when there aren't any interrupts.
 */
  opal_flush_console(termno);
 } while(count == 0 || count == -EAGAIN);
}

static int udbg_opal_getc_poll(void)
{
 unsigned int termno = hvc_opal_boot_termno;
 int rc = 0;
 char c;

 switch(hvc_opal_boot_priv.proto) {
 case HV_PROTOCOL_RAW:
  rc = opal_get_chars(termno, &c, 1);
  break;
 case HV_PROTOCOL_HVSI:
  rc = hvc_opal_hvsi_get_chars(termno, &c, 1);
  break;
 }
 if (!rc)
  return -1;
 return c;
}

static int udbg_opal_getc(void)
{
 int ch;
 for (;;) {
  ch = udbg_opal_getc_poll();
  if (ch != -1)
   return ch;
 }
}

static void udbg_init_opal_common(void)
{
 udbg_putc = udbg_opal_putc;
 udbg_getc = udbg_opal_getc;
 udbg_getc_poll = udbg_opal_getc_poll;
}

void __init hvc_opal_init_early(void)
{
 struct device_node *stdout_node = of_node_get(of_stdout);
 const __be32 *termno;
 const struct hv_ops *ops;
 u32 index;

 /* If the console wasn't in /chosen, try /ibm,opal */
 if (!stdout_node) {
  struct device_node *opal, *np;

  /* Current OPAL takeover doesn't provide the stdout
 * path, so we hard wire it
 */
  opal = of_find_node_by_path("/ibm,opal/consoles");
  if (opal) {
   pr_devel("hvc_opal: Found consoles in new location\n");
  } else {
   opal = of_find_node_by_path("/ibm,opal");
   if (opal)
    pr_devel("hvc_opal: "
      "Found consoles in old location\n");
  }
  if (!opal)
   return;
  for_each_child_of_node(opal, np) {
   if (of_node_name_eq(np, "serial")) {
    stdout_node = np;
    break;
   }
  }
  of_node_put(opal);
 }
 if (!stdout_node)
  return;
 termno = of_get_property(stdout_node, "reg", NULL);
 index = termno ? be32_to_cpup(termno) : 0;
 if (index >= MAX_NR_HVC_CONSOLES)
  return;
 hvc_opal_privs[index] = &hvc_opal_boot_priv;

 /* Check the protocol */
 if (of_device_is_compatible(stdout_node, "ibm,opal-console-raw")) {
  hvc_opal_boot_priv.proto = HV_PROTOCOL_RAW;
  ops = &hvc_opal_raw_ops;
  pr_devel("hvc_opal: Found RAW console\n");
 }
 else if (of_device_is_compatible(stdout_node,"ibm,opal-console-hvsi")) {
  hvc_opal_boot_priv.proto = HV_PROTOCOL_HVSI;
  ops = &hvc_opal_hvsi_ops;
  hvsilib_init(&hvc_opal_boot_priv.hvsi,
        opal_get_chars, opal_put_chars_atomic,
        index, 1);
  /* HVSI, perform the handshake now */
  hvsilib_establish(&hvc_opal_boot_priv.hvsi);
  pr_devel("hvc_opal: Found HVSI console\n");
 } else
  goto out;
 hvc_opal_boot_termno = index;
 udbg_init_opal_common();
 add_preferred_console("hvc", index, NULL);
 hvc_instantiate(index, index, ops);
out:
 of_node_put(stdout_node);
}

#ifdef CONFIG_PPC_EARLY_DEBUG_OPAL_RAW
void __init udbg_init_debug_opal_raw(void)
{
 u32 index = CONFIG_PPC_EARLY_DEBUG_OPAL_VTERMNO;
 hvc_opal_privs[index] = &hvc_opal_boot_priv;
 hvc_opal_boot_priv.proto = HV_PROTOCOL_RAW;
 hvc_opal_boot_termno = index;
 udbg_init_opal_common();
}
#endif /* CONFIG_PPC_EARLY_DEBUG_OPAL_RAW */

#ifdef CONFIG_PPC_EARLY_DEBUG_OPAL_HVSI
void __init udbg_init_debug_opal_hvsi(void)
{
 u32 index = CONFIG_PPC_EARLY_DEBUG_OPAL_VTERMNO;
 hvc_opal_privs[index] = &hvc_opal_boot_priv;
 hvc_opal_boot_termno = index;
 udbg_init_opal_common();
 hvsilib_init(&hvc_opal_boot_priv.hvsi,
       opal_get_chars, opal_put_chars_atomic,
       index, 1);
 hvsilib_establish(&hvc_opal_boot_priv.hvsi);
}
#endif /* CONFIG_PPC_EARLY_DEBUG_OPAL_HVSI */