pc-bios/s390-ccw/main.c - third_party/qemu - Git at Google

 /*
  * S390 virtio-ccw loading program
  *
  * Copyright (c) 2013 Alexander Graf <agraf@suse.de>
  *
  * This work is licensed under the terms of the GNU GPL, version 2 or (at
  * your option) any later version. See the COPYING file in the top-level
  * directory.
  */

 #include "libc.h"
 #include "helper.h"
 #include "s390-arch.h"
 #include "s390-ccw.h"
 #include "cio.h"
 #include "virtio.h"
 #include "virtio-scsi.h"
 #include "dasd-ipl.h"

 char stack[PAGE_SIZE * 8] __attribute__((__aligned__(PAGE_SIZE)));
 static SubChannelId blk_schid = { .one = 1 };
 static char loadparm_str[LOADPARM_LEN + 1];
 QemuIplParameters qipl;
 IplParameterBlock iplb __attribute__((__aligned__(PAGE_SIZE)));
 static bool have_iplb;
 static uint16_t cutype;
 LowCore *lowcore; /* Yes, this *is* a pointer to address 0 */

 #define LOADPARM_PROMPT "PROMPT  "
 #define LOADPARM_EMPTY  "        "
 #define BOOT_MENU_FLAG_MASK (QIPL_FLAG_BM_OPTS_CMD | QIPL_FLAG_BM_OPTS_ZIPL)

 /*
  * Principles of Operations (SA22-7832-09) chapter 17 requires that
  * a subsystem-identification is at 184-187 and bytes 188-191 are zero
  * after list-directed-IPL and ccw-IPL.
  */
 void write_subsystem_identification(void)
 {
     lowcore->subchannel_id = blk_schid.sch_id;
     lowcore->subchannel_nr = blk_schid.sch_no;
     lowcore->io_int_parm = 0;
 }

 void write_iplb_location(void)
 {
     if (cutype == CU_TYPE_VIRTIO && virtio_get_device_type() != VIRTIO_ID_NET) {
         lowcore->ptr_iplb = ptr2u32(&iplb);
     }
 }

 unsigned int get_loadparm_index(void)
 {
     return atoui(loadparm_str);
 }

 static int is_dev_possibly_bootable(int dev_no, int sch_no)
 {
     bool is_virtio;
     Schib schib;
     int r;

     blk_schid.sch_no = sch_no;
     r = stsch_err(blk_schid, &schib);
     if (r == 3 || r == -EIO) {
         return -ENODEV;
     }
     if (!schib.pmcw.dnv) {
         return false;
     }

     enable_subchannel(blk_schid);
     cutype = cu_type(blk_schid);

     /*
      * Note: we always have to run virtio_is_supported() here to make
      * sure that the vdev.senseid data gets pre-initialized correctly
      */
     is_virtio = virtio_is_supported(blk_schid);

     /* No specific devno given, just return whether the device is possibly bootable */
     if (dev_no < 0) {
         switch (cutype) {
         case CU_TYPE_VIRTIO:
             if (is_virtio) {
                 /*
                  * Skip net devices since no IPLB is created and therefore
                  * no network bootloader has been loaded
                  */
                 if (virtio_get_device_type() != VIRTIO_ID_NET) {
                     return true;
                 }
             }
             return false;
         case CU_TYPE_DASD_3990:
         case CU_TYPE_DASD_2107:
             return true;
         default:
             return false;
         }
     }

     /* Caller asked for a specific devno */
     if (schib.pmcw.dev == dev_no) {
         return true;
     }

     return false;
 }

 /*
  * Find the subchannel connected to the given device (dev_no) and fill in the
  * subchannel information block (schib) with the connected subchannel's info.
  * NOTE: The global variable blk_schid is updated to contain the subchannel
  * information.
  *
  * If the caller gives dev_no=-1 then the user did not specify a boot device.
  * In this case we'll just use the first potentially bootable device we find.
  */
 static bool find_subch(int dev_no)
 {
     int i, r;

     for (i = 0; i < 0x10000; i++) {
         r = is_dev_possibly_bootable(dev_no, i);
         if (r < 0) {
             break;
         }
         if (r == true) {
             return true;
         }
     }

     return false;
 }

 static void menu_setup(void)
 {
     if (memcmp(loadparm_str, LOADPARM_PROMPT, LOADPARM_LEN) == 0) {
         menu_set_parms(QIPL_FLAG_BM_OPTS_CMD, 0);
         return;
     }

     /* If loadparm was set to any other value, then do not enable menu */
     if (memcmp(loadparm_str, LOADPARM_EMPTY, LOADPARM_LEN) != 0) {
         return;
     }

     switch (iplb.pbt) {
     case S390_IPL_TYPE_CCW:
     case S390_IPL_TYPE_QEMU_SCSI:
         menu_set_parms(qipl.qipl_flags & BOOT_MENU_FLAG_MASK,
                        qipl.boot_menu_timeout);
         return;
     }
 }

 /*
  * Initialize the channel I/O subsystem so we can talk to our ipl/boot device.
  */
 static void css_setup(void)
 {
     /*
      * Unconditionally enable mss support. In every sane configuration this
      * will succeed; and even if it doesn't, stsch_err() can handle it.
      */
     enable_mss_facility();
 }

 /*
  * Collect various pieces of information from the hypervisor/hardware that
  * we'll use to determine exactly how we'll boot.
  */
 static void boot_setup(void)
 {
     char lpmsg[] = "LOADPARM=[________]\n";

     sclp_get_loadparm_ascii(loadparm_str);
     memcpy(lpmsg + 10, loadparm_str, 8);
     sclp_print(lpmsg);

     /*
      * Clear out any potential S390EP magic (see jump_to_low_kernel()),
      * so we don't taint our decision-making process during a reboot.
      */
     memset((char *)S390EP, 0, 6);

     have_iplb = store_iplb(&iplb);
 }

 static void find_boot_device(void)
 {
     VDev *vdev = virtio_get_device();
     bool found;

     switch (iplb.pbt) {
     case S390_IPL_TYPE_CCW:
         debug_print_int("device no. ", iplb.ccw.devno);
         blk_schid.ssid = iplb.ccw.ssid & 0x3;
         debug_print_int("ssid ", blk_schid.ssid);
         found = find_subch(iplb.ccw.devno);
         break;
     case S390_IPL_TYPE_QEMU_SCSI:
         vdev->scsi_device_selected = true;
         vdev->selected_scsi_device.channel = iplb.scsi.channel;
         vdev->selected_scsi_device.target = iplb.scsi.target;
         vdev->selected_scsi_device.lun = iplb.scsi.lun;
         blk_schid.ssid = iplb.scsi.ssid & 0x3;
         found = find_subch(iplb.scsi.devno);
         break;
     default:
         panic("List-directed IPL not supported yet!\n");
     }

     IPL_assert(found, "Boot device not found\n");
 }

 static int virtio_setup(void)
 {
     VDev *vdev = virtio_get_device();
     QemuIplParameters *early_qipl = (QemuIplParameters *)QIPL_ADDRESS;
     int ret;

     memcpy(&qipl, early_qipl, sizeof(QemuIplParameters));

     if (have_iplb) {
         menu_setup();
     }

     switch (vdev->senseid.cu_model) {
     case VIRTIO_ID_NET:
         sclp_print("Network boot device detected\n");
         vdev->netboot_start_addr = qipl.netboot_start_addr;
         return 0;
     case VIRTIO_ID_BLOCK:
         ret = virtio_blk_setup_device(blk_schid);
         break;
     case VIRTIO_ID_SCSI:
         ret = virtio_scsi_setup_device(blk_schid);
         break;
     default:
         panic("\n! No IPL device available !\n");
     }

     if (!ret) {
         IPL_assert(virtio_ipl_disk_is_valid(), "No valid IPL device detected");
     }

     return ret;
 }

 static void ipl_boot_device(void)
 {
     switch (cutype) {
     case CU_TYPE_DASD_3990:
     case CU_TYPE_DASD_2107:
         dasd_ipl(blk_schid, cutype); /* no return */
         break;
     case CU_TYPE_VIRTIO:
         if (virtio_setup() == 0) {
             zipl_load();             /* Only returns in case of errors */
         }
         break;
     default:
         print_int("Attempting to boot from unexpected device type", cutype);
         panic("\nBoot failed.\n");
     }
 }

 /*
  * No boot device has been specified, so we have to scan through the
  * channels to find one.
  */
 static void probe_boot_device(void)
 {
     int ssid, sch_no, ret;

     for (ssid = 0; ssid < 0x3; ssid++) {
         blk_schid.ssid = ssid;
         for (sch_no = 0; sch_no < 0x10000; sch_no++) {
             ret = is_dev_possibly_bootable(-1, sch_no);
             if (ret < 0) {
                 break;
             }
             if (ret == true) {
                 ipl_boot_device();      /* Only returns if unsuccessful */
             }
         }
     }

     sclp_print("Could not find a suitable boot device (none specified)\n");
 }

 void main(void)
 {
     sclp_setup();
     css_setup();
     boot_setup();
     if (have_iplb) {
         find_boot_device();
         ipl_boot_device();
     } else {
         probe_boot_device();
     }

     panic("Failed to load OS from hard disk\n");
 }
	/*
	* S390 virtio-ccw loading program
	*
	* Copyright (c) 2013 Alexander Graf <agraf@suse.de>
	*
	* This work is licensed under the terms of the GNU GPL, version 2 or (at
	* your option) any later version. See the COPYING file in the top-level
	* directory.
	*/

	#include "libc.h"
	#include "helper.h"
	#include "s390-arch.h"
	#include "s390-ccw.h"
	#include "cio.h"
	#include "virtio.h"
	#include "virtio-scsi.h"
	#include "dasd-ipl.h"

	char stack[PAGE_SIZE * 8] __attribute__((__aligned__(PAGE_SIZE)));
	static SubChannelId blk_schid = { .one = 1 };
	static char loadparm_str[LOADPARM_LEN + 1];
	QemuIplParameters qipl;
	IplParameterBlock iplb __attribute__((__aligned__(PAGE_SIZE)));
	static bool have_iplb;
	static uint16_t cutype;
	LowCore lowcore; / Yes, this is a pointer to address 0 */

	#define LOADPARM_PROMPT "PROMPT "
	#define LOADPARM_EMPTY " "
	#define BOOT_MENU_FLAG_MASK (QIPL_FLAG_BM_OPTS_CMD \| QIPL_FLAG_BM_OPTS_ZIPL)

	/*
	* Principles of Operations (SA22-7832-09) chapter 17 requires that
	* a subsystem-identification is at 184-187 and bytes 188-191 are zero
	* after list-directed-IPL and ccw-IPL.
	*/
	void write_subsystem_identification(void)
	{
	lowcore->subchannel_id = blk_schid.sch_id;
	lowcore->subchannel_nr = blk_schid.sch_no;
	lowcore->io_int_parm = 0;
	}

	void write_iplb_location(void)
	{
	if (cutype == CU_TYPE_VIRTIO && virtio_get_device_type() != VIRTIO_ID_NET) {
	lowcore->ptr_iplb = ptr2u32(&iplb);
	}
	}

	unsigned int get_loadparm_index(void)
	{
	return atoui(loadparm_str);
	}

	static int is_dev_possibly_bootable(int dev_no, int sch_no)
	{
	bool is_virtio;
	Schib schib;
	int r;

	blk_schid.sch_no = sch_no;
	r = stsch_err(blk_schid, &schib);
	if (r == 3 \|\| r == -EIO) {
	return -ENODEV;
	}
	if (!schib.pmcw.dnv) {
	return false;
	}

	enable_subchannel(blk_schid);
	cutype = cu_type(blk_schid);

	/*
	* Note: we always have to run virtio_is_supported() here to make
	* sure that the vdev.senseid data gets pre-initialized correctly
	*/
	is_virtio = virtio_is_supported(blk_schid);

	/* No specific devno given, just return whether the device is possibly bootable */
	if (dev_no < 0) {
	switch (cutype) {
	case CU_TYPE_VIRTIO:
	if (is_virtio) {
	/*
	* Skip net devices since no IPLB is created and therefore
	* no network bootloader has been loaded
	*/
	if (virtio_get_device_type() != VIRTIO_ID_NET) {
	return true;
	}
	}
	return false;
	case CU_TYPE_DASD_3990:
	case CU_TYPE_DASD_2107:
	return true;
	default:
	return false;
	}
	}

	/* Caller asked for a specific devno */
	if (schib.pmcw.dev == dev_no) {
	return true;
	}

	return false;
	}

	/*
	* Find the subchannel connected to the given device (dev_no) and fill in the
	* subchannel information block (schib) with the connected subchannel's info.
	* NOTE: The global variable blk_schid is updated to contain the subchannel
	* information.
	*
	* If the caller gives dev_no=-1 then the user did not specify a boot device.
	* In this case we'll just use the first potentially bootable device we find.
	*/
	static bool find_subch(int dev_no)
	{
	int i, r;

	for (i = 0; i < 0x10000; i++) {
	r = is_dev_possibly_bootable(dev_no, i);
	if (r < 0) {
	break;
	}
	if (r == true) {
	return true;
	}
	}

	return false;
	}

	static void menu_setup(void)
	{
	if (memcmp(loadparm_str, LOADPARM_PROMPT, LOADPARM_LEN) == 0) {
	menu_set_parms(QIPL_FLAG_BM_OPTS_CMD, 0);
	return;
	}

	/* If loadparm was set to any other value, then do not enable menu */
	if (memcmp(loadparm_str, LOADPARM_EMPTY, LOADPARM_LEN) != 0) {
	return;
	}

	switch (iplb.pbt) {
	case S390_IPL_TYPE_CCW:
	case S390_IPL_TYPE_QEMU_SCSI:
	menu_set_parms(qipl.qipl_flags & BOOT_MENU_FLAG_MASK,
	qipl.boot_menu_timeout);
	return;
	}
	}

	/*
	* Initialize the channel I/O subsystem so we can talk to our ipl/boot device.
	*/
	static void css_setup(void)
	{
	/*
	* Unconditionally enable mss support. In every sane configuration this
	* will succeed; and even if it doesn't, stsch_err() can handle it.
	*/
	enable_mss_facility();
	}

	/*
	* Collect various pieces of information from the hypervisor/hardware that
	* we'll use to determine exactly how we'll boot.
	*/
	static void boot_setup(void)
	{
	char lpmsg[] = "LOADPARM=[________]\n";

	sclp_get_loadparm_ascii(loadparm_str);
	memcpy(lpmsg + 10, loadparm_str, 8);
	sclp_print(lpmsg);

	/*
	* Clear out any potential S390EP magic (see jump_to_low_kernel()),
	* so we don't taint our decision-making process during a reboot.
	*/
	memset((char *)S390EP, 0, 6);

	have_iplb = store_iplb(&iplb);
	}

	static void find_boot_device(void)
	{
	VDev *vdev = virtio_get_device();
	bool found;

	switch (iplb.pbt) {
	case S390_IPL_TYPE_CCW:
	debug_print_int("device no. ", iplb.ccw.devno);
	blk_schid.ssid = iplb.ccw.ssid & 0x3;
	debug_print_int("ssid ", blk_schid.ssid);
	found = find_subch(iplb.ccw.devno);
	break;
	case S390_IPL_TYPE_QEMU_SCSI:
	vdev->scsi_device_selected = true;
	vdev->selected_scsi_device.channel = iplb.scsi.channel;
	vdev->selected_scsi_device.target = iplb.scsi.target;
	vdev->selected_scsi_device.lun = iplb.scsi.lun;
	blk_schid.ssid = iplb.scsi.ssid & 0x3;
	found = find_subch(iplb.scsi.devno);
	break;
	default:
	panic("List-directed IPL not supported yet!\n");
	}

	IPL_assert(found, "Boot device not found\n");
	}

	static int virtio_setup(void)
	{
	VDev *vdev = virtio_get_device();
	QemuIplParameters early_qipl = (QemuIplParameters )QIPL_ADDRESS;
	int ret;

	memcpy(&qipl, early_qipl, sizeof(QemuIplParameters));

	if (have_iplb) {
	menu_setup();
	}

	switch (vdev->senseid.cu_model) {
	case VIRTIO_ID_NET:
	sclp_print("Network boot device detected\n");
	vdev->netboot_start_addr = qipl.netboot_start_addr;
	return 0;
	case VIRTIO_ID_BLOCK:
	ret = virtio_blk_setup_device(blk_schid);
	break;
	case VIRTIO_ID_SCSI:
	ret = virtio_scsi_setup_device(blk_schid);
	break;
	default:
	panic("\n! No IPL device available !\n");
	}

	if (!ret) {
	IPL_assert(virtio_ipl_disk_is_valid(), "No valid IPL device detected");
	}

	return ret;
	}

	static void ipl_boot_device(void)
	{
	switch (cutype) {
	case CU_TYPE_DASD_3990:
	case CU_TYPE_DASD_2107:
	dasd_ipl(blk_schid, cutype); /* no return */
	break;
	case CU_TYPE_VIRTIO:
	if (virtio_setup() == 0) {
	zipl_load(); /* Only returns in case of errors */
	}
	break;
	default:
	print_int("Attempting to boot from unexpected device type", cutype);
	panic("\nBoot failed.\n");
	}
	}

	/*
	* No boot device has been specified, so we have to scan through the
	* channels to find one.
	*/
	static void probe_boot_device(void)
	{
	int ssid, sch_no, ret;

	for (ssid = 0; ssid < 0x3; ssid++) {
	blk_schid.ssid = ssid;
	for (sch_no = 0; sch_no < 0x10000; sch_no++) {
	ret = is_dev_possibly_bootable(-1, sch_no);
	if (ret < 0) {
	break;
	}
	if (ret == true) {
	ipl_boot_device(); /* Only returns if unsuccessful */
	}
	}
	}

	sclp_print("Could not find a suitable boot device (none specified)\n");
	}

	void main(void)
	{
	sclp_setup();
	css_setup();
	boot_setup();
	if (have_iplb) {
	find_boot_device();
	ipl_boot_device();
	} else {
	probe_boot_device();
	}

	panic("Failed to load OS from hard disk\n");
	}