1 files changed, 473 insertions, 0 deletions
diff --git a/drivers/tty/hvc/hvc_vio.c b/drivers/tty/hvc/hvc_vio.c
new file mode 100644
index 000000000..7af54d6ed
--- /dev/null
+++ b/drivers/tty/hvc/hvc_vio.c
@@ -0,0 +1,473 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * vio driver interface to hvc_console.c
+ *
+ * This code was moved here to allow the remaining code to be reused as a
+ * generic polling mode with semi-reliable transport driver core to the
+ * console and tty subsystems.
+ *
+ *
+ * Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM
+ * Copyright (C) 2001 Paul Mackerras <paulus@au.ibm.com>, IBM
+ * Copyright (C) 2004 Benjamin Herrenschmidt <benh@kernel.crashing.org>, IBM Corp.
+ * Copyright (C) 2004 IBM Corporation
+ *
+ * Additional Author(s):
+ *  Ryan S. Arnold <rsa@us.ibm.com>
+ *
+ * TODO:
+ *
+ *   - handle error in sending hvsi protocol packets
+ *   - retry nego on subsequent sends ?
+ */
+
+#undef DEBUG
+
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/console.h>
+
+#include <asm/hvconsole.h>
+#include <asm/vio.h>
+#include <asm/prom.h>
+#include <asm/hvsi.h>
+#include <asm/udbg.h>
+#include <asm/machdep.h>
+
+#include "hvc_console.h"
+
+static const char hvc_driver_name[] = "hvc_console";
+
+static const struct vio_device_id hvc_driver_table[] = {
+	{"serial", "hvterm1"},
+#ifndef HVC_OLD_HVSI
+	{"serial", "hvterm-protocol"},
+#endif
+	{ "", "" }
+};
+
+typedef enum hv_protocol {
+	HV_PROTOCOL_RAW,
+	HV_PROTOCOL_HVSI
+} hv_protocol_t;
+
+struct hvterm_priv {
+	u32			termno;	/* HV term number */
+	hv_protocol_t		proto;	/* Raw data or HVSI packets */
+	struct hvsi_priv	hvsi;	/* HVSI specific data */
+	spinlock_t		buf_lock;
+	char			buf[SIZE_VIO_GET_CHARS];
+	int			left;
+	int			offset;
+};
+static struct hvterm_priv *hvterm_privs[MAX_NR_HVC_CONSOLES];
+/* For early boot console */
+static struct hvterm_priv hvterm_priv0;
+
+static int hvterm_raw_get_chars(uint32_t vtermno, char *buf, int count)
+{
+	struct hvterm_priv *pv = hvterm_privs[vtermno];
+	unsigned long i;
+	unsigned long flags;
+	int got;
+
+	if (WARN_ON(!pv))
+		return 0;
+
+	spin_lock_irqsave(&pv->buf_lock, flags);
+
+	if (pv->left == 0) {
+		pv->offset = 0;
+		pv->left = hvc_get_chars(pv->termno, pv->buf, count);
+
+		/*
+		 * Work around a HV bug where it gives us a null
+		 * after every \r.  -- paulus
+		 */
+		for (i = 1; i < pv->left; ++i) {
+			if (pv->buf[i] == 0 && pv->buf[i-1] == '\r') {
+				--pv->left;
+				if (i < pv->left) {
+					memmove(&pv->buf[i], &pv->buf[i+1],
+						pv->left - i);
+				}
+			}
+		}
+	}
+
+	got = min(count, pv->left);
+	memcpy(buf, &pv->buf[pv->offset], got);
+	pv->offset += got;
+	pv->left -= got;
+
+	spin_unlock_irqrestore(&pv->buf_lock, flags);
+
+	return got;
+}
+
+/**
+ * hvterm_raw_put_chars: send characters to firmware for given vterm adapter
+ * @vtermno: The virtual terminal number.
+ * @buf: The characters to send. Because of the underlying hypercall in
+ *       hvc_put_chars(), this buffer must be at least 16 bytes long, even if
+ *       you are sending fewer chars.
+ * @count: number of chars to send.
+ */
+static int hvterm_raw_put_chars(uint32_t vtermno, const char *buf, int count)
+{
+	struct hvterm_priv *pv = hvterm_privs[vtermno];
+
+	if (WARN_ON(!pv))
+		return 0;
+
+	return hvc_put_chars(pv->termno, buf, count);
+}
+
+static const struct hv_ops hvterm_raw_ops = {
+	.get_chars = hvterm_raw_get_chars,
+	.put_chars = hvterm_raw_put_chars,
+	.notifier_add = notifier_add_irq,
+	.notifier_del = notifier_del_irq,
+	.notifier_hangup = notifier_hangup_irq,
+};
+
+static int hvterm_hvsi_get_chars(uint32_t vtermno, char *buf, int count)
+{
+	struct hvterm_priv *pv = hvterm_privs[vtermno];
+
+	if (WARN_ON(!pv))
+		return 0;
+
+	return hvsilib_get_chars(&pv->hvsi, buf, count);
+}
+
+static int hvterm_hvsi_put_chars(uint32_t vtermno, const char *buf, int count)
+{
+	struct hvterm_priv *pv = hvterm_privs[vtermno];
+
+	if (WARN_ON(!pv))
+		return 0;
+
+	return hvsilib_put_chars(&pv->hvsi, buf, count);
+}
+
+static int hvterm_hvsi_open(struct hvc_struct *hp, int data)
+{
+	struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
+	int rc;
+
+	pr_devel("HVSI@%x: open !\n", pv->termno);
+
+	rc = notifier_add_irq(hp, data);
+	if (rc)
+		return rc;
+
+	return hvsilib_open(&pv->hvsi, hp);
+}
+
+static void hvterm_hvsi_close(struct hvc_struct *hp, int data)
+{
+	struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
+
+	pr_devel("HVSI@%x: do close !\n", pv->termno);
+
+	hvsilib_close(&pv->hvsi, hp);
+
+	notifier_del_irq(hp, data);
+}
+
+void hvterm_hvsi_hangup(struct hvc_struct *hp, int data)
+{
+	struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
+
+	pr_devel("HVSI@%x: do hangup !\n", pv->termno);
+
+	hvsilib_close(&pv->hvsi, hp);
+
+	notifier_hangup_irq(hp, data);
+}
+
+static int hvterm_hvsi_tiocmget(struct hvc_struct *hp)
+{
+	struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
+
+	if (!pv)
+		return -EINVAL;
+	return pv->hvsi.mctrl;
+}
+
+static int hvterm_hvsi_tiocmset(struct hvc_struct *hp, unsigned int set,
+				unsigned int clear)
+{
+	struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
+
+	pr_devel("HVSI@%x: Set modem control, set=%x,clr=%x\n",
+		 pv->termno, 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 hvterm_hvsi_ops = {
+	.get_chars = hvterm_hvsi_get_chars,
+	.put_chars = hvterm_hvsi_put_chars,
+	.notifier_add = hvterm_hvsi_open,
+	.notifier_del = hvterm_hvsi_close,
+	.notifier_hangup = hvterm_hvsi_hangup,
+	.tiocmget = hvterm_hvsi_tiocmget,
+	.tiocmset = hvterm_hvsi_tiocmset,
+};
+
+static void udbg_hvc_putc(char c)
+{
+	int count = -1;
+	unsigned char bounce_buffer[16];
+
+	if (!hvterm_privs[0])
+		return;
+
+	if (c == '\n')
+		udbg_hvc_putc('\r');
+
+	do {
+		switch(hvterm_privs[0]->proto) {
+		case HV_PROTOCOL_RAW:
+			/*
+			 * hvterm_raw_put_chars requires at least a 16-byte
+			 * buffer, so go via the bounce buffer
+			 */
+			bounce_buffer[0] = c;
+			count = hvterm_raw_put_chars(0, bounce_buffer, 1);
+			break;
+		case HV_PROTOCOL_HVSI:
+			count = hvterm_hvsi_put_chars(0, &c, 1);
+			break;
+		}
+	} while(count == 0);
+}
+
+static int udbg_hvc_getc_poll(void)
+{
+	int rc = 0;
+	char c;
+
+	if (!hvterm_privs[0])
+		return -1;
+
+	switch(hvterm_privs[0]->proto) {
+	case HV_PROTOCOL_RAW:
+		rc = hvterm_raw_get_chars(0, &c, 1);
+		break;
+	case HV_PROTOCOL_HVSI:
+		rc = hvterm_hvsi_get_chars(0, &c, 1);
+		break;
+	}
+	if (!rc)
+		return -1;
+	return c;
+}
+
+static int udbg_hvc_getc(void)
+{
+	int ch;
+
+	if (!hvterm_privs[0])
+		return -1;
+
+	for (;;) {
+		ch = udbg_hvc_getc_poll();
+		if (ch == -1) {
+			/* This shouldn't be needed...but... */
+			volatile unsigned long delay;
+			for (delay=0; delay < 2000000; delay++)
+				;
+		} else {
+			return ch;
+		}
+	}
+}
+
+static int hvc_vio_probe(struct vio_dev *vdev,
+				   const struct vio_device_id *id)
+{
+	const struct hv_ops *ops;
+	struct hvc_struct *hp;
+	struct hvterm_priv *pv;
+	hv_protocol_t proto;
+	int i, termno = -1;
+
+	/* probed with invalid parameters. */
+	if (!vdev || !id)
+		return -EPERM;
+
+	if (of_device_is_compatible(vdev->dev.of_node, "hvterm1")) {
+		proto = HV_PROTOCOL_RAW;
+		ops = &hvterm_raw_ops;
+	} else if (of_device_is_compatible(vdev->dev.of_node, "hvterm-protocol")) {
+		proto = HV_PROTOCOL_HVSI;
+		ops = &hvterm_hvsi_ops;
+	} else {
+		pr_err("hvc_vio: Unknown protocol for %pOF\n", vdev->dev.of_node);
+		return -ENXIO;
+	}
+
+	pr_devel("hvc_vio_probe() device %pOF, using %s protocol\n",
+		 vdev->dev.of_node,
+		 proto == HV_PROTOCOL_RAW ? "raw" : "hvsi");
+
+	/* Is it our boot one ? */
+	if (hvterm_privs[0] == &hvterm_priv0 &&
+	    vdev->unit_address == hvterm_priv0.termno) {
+		pv = hvterm_privs[0];
+		termno = 0;
+		pr_devel("->boot console, using termno 0\n");
+	}
+	/* nope, allocate a new one */
+	else {
+		for (i = 0; i < MAX_NR_HVC_CONSOLES && termno < 0; i++)
+			if (!hvterm_privs[i])
+				termno = i;
+		pr_devel("->non-boot console, using termno %d\n", termno);
+		if (termno < 0)
+			return -ENODEV;
+		pv = kzalloc(sizeof(struct hvterm_priv), GFP_KERNEL);
+		if (!pv)
+			return -ENOMEM;
+		pv->termno = vdev->unit_address;
+		pv->proto = proto;
+		spin_lock_init(&pv->buf_lock);
+		hvterm_privs[termno] = pv;
+		hvsilib_init(&pv->hvsi, hvc_get_chars, hvc_put_chars,
+			     pv->termno, 0);
+	}
+
+	hp = hvc_alloc(termno, vdev->irq, ops, MAX_VIO_PUT_CHARS);
+	if (IS_ERR(hp))
+		return PTR_ERR(hp);
+	dev_set_drvdata(&vdev->dev, hp);
+
+	/* register udbg if it's not there already for console 0 */
+	if (hp->index == 0 && !udbg_putc) {
+		udbg_putc = udbg_hvc_putc;
+		udbg_getc = udbg_hvc_getc;
+		udbg_getc_poll = udbg_hvc_getc_poll;
+	}
+
+	return 0;
+}
+
+static struct vio_driver hvc_vio_driver = {
+	.id_table	= hvc_driver_table,
+	.probe		= hvc_vio_probe,
+	.name		= hvc_driver_name,
+	.driver = {
+		.suppress_bind_attrs	= true,
+	},
+};
+
+static int __init hvc_vio_init(void)
+{
+	int rc;
+
+	/* Register as a vio device to receive callbacks */
+	rc = vio_register_driver(&hvc_vio_driver);
+
+	return rc;
+}
+device_initcall(hvc_vio_init); /* after drivers/tty/hvc/hvc_console.c */
+
+void __init hvc_vio_init_early(void)
+{
+	const __be32 *termno;
+	const struct hv_ops *ops;
+
+	/* find the boot console from /chosen/stdout */
+	/* Check if it's a virtual terminal */
+	if (!of_node_name_prefix(of_stdout, "vty"))
+		return;
+	termno = of_get_property(of_stdout, "reg", NULL);
+	if (termno == NULL)
+		return;
+	hvterm_priv0.termno = of_read_number(termno, 1);
+	spin_lock_init(&hvterm_priv0.buf_lock);
+	hvterm_privs[0] = &hvterm_priv0;
+
+	/* Check the protocol */
+	if (of_device_is_compatible(of_stdout, "hvterm1")) {
+		hvterm_priv0.proto = HV_PROTOCOL_RAW;
+		ops = &hvterm_raw_ops;
+	}
+	else if (of_device_is_compatible(of_stdout, "hvterm-protocol")) {
+		hvterm_priv0.proto = HV_PROTOCOL_HVSI;
+		ops = &hvterm_hvsi_ops;
+		hvsilib_init(&hvterm_priv0.hvsi, hvc_get_chars, hvc_put_chars,
+			     hvterm_priv0.termno, 1);
+		/* HVSI, perform the handshake now */
+		hvsilib_establish(&hvterm_priv0.hvsi);
+	} else
+		return;
+	udbg_putc = udbg_hvc_putc;
+	udbg_getc = udbg_hvc_getc;
+	udbg_getc_poll = udbg_hvc_getc_poll;
+#ifdef HVC_OLD_HVSI
+	/* When using the old HVSI driver don't register the HVC
+	 * backend for HVSI, only do udbg
+	 */
+	if (hvterm_priv0.proto == HV_PROTOCOL_HVSI)
+		return;
+#endif
+	/* Check whether the user has requested a different console. */
+	if (!strstr(boot_command_line, "console="))
+		add_preferred_console("hvc", 0, NULL);
+	hvc_instantiate(0, 0, ops);
+}
+
+/* call this from early_init() for a working debug console on
+ * vterm capable LPAR machines
+ */
+#ifdef CONFIG_PPC_EARLY_DEBUG_LPAR
+void __init udbg_init_debug_lpar(void)
+{
+	/*
+	 * If we're running as a hypervisor then we definitely can't call the
+	 * hypervisor to print debug output (we *are* the hypervisor), so don't
+	 * register if we detect that MSR_HV=1.
+	 */
+	if (mfmsr() & MSR_HV)
+		return;
+
+	hvterm_privs[0] = &hvterm_priv0;
+	hvterm_priv0.termno = 0;
+	hvterm_priv0.proto = HV_PROTOCOL_RAW;
+	spin_lock_init(&hvterm_priv0.buf_lock);
+	udbg_putc = udbg_hvc_putc;
+	udbg_getc = udbg_hvc_getc;
+	udbg_getc_poll = udbg_hvc_getc_poll;
+}
+#endif /* CONFIG_PPC_EARLY_DEBUG_LPAR */
+
+#ifdef CONFIG_PPC_EARLY_DEBUG_LPAR_HVSI
+void __init udbg_init_debug_lpar_hvsi(void)
+{
+	/* See comment above in udbg_init_debug_lpar() */
+	if (mfmsr() & MSR_HV)
+		return;
+
+	hvterm_privs[0] = &hvterm_priv0;
+	hvterm_priv0.termno = CONFIG_PPC_EARLY_DEBUG_HVSI_VTERMNO;
+	hvterm_priv0.proto = HV_PROTOCOL_HVSI;
+	spin_lock_init(&hvterm_priv0.buf_lock);
+	udbg_putc = udbg_hvc_putc;
+	udbg_getc = udbg_hvc_getc;
+	udbg_getc_poll = udbg_hvc_getc_poll;
+	hvsilib_init(&hvterm_priv0.hvsi, hvc_get_chars, hvc_put_chars,
+		     hvterm_priv0.termno, 1);
+	hvsilib_establish(&hvterm_priv0.hvsi);
+}
+#endif /* CONFIG_PPC_EARLY_DEBUG_LPAR_HVSI */