0f79b89bc2
If no bootdevice was specified, we try to autodetect a suitable IPL device. Current code only searched in subchannel set 0; extend this search to higher subchannel sets as well. Signed-off-by: Alexander Yarygin <yarygin@linux.vnet.ibm.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
117 lines
2.7 KiB
C
117 lines
2.7 KiB
C
/*
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* S390 virtio-ccw loading program
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*
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* Copyright (c) 2013 Alexander Graf <agraf@suse.de>
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*
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* This work is licensed under the terms of the GNU GPL, version 2 or (at
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* your option) any later version. See the COPYING file in the top-level
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* directory.
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*/
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#include "s390-ccw.h"
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#include "virtio.h"
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char stack[PAGE_SIZE * 8] __attribute__((__aligned__(PAGE_SIZE)));
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char ring_area[PAGE_SIZE * 8] __attribute__((__aligned__(PAGE_SIZE)));
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uint64_t boot_value;
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static struct subchannel_id blk_schid = { .one = 1 };
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/*
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* Priniciples of Operations (SA22-7832-09) chapter 17 requires that
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* a subsystem-identification is at 184-187 and bytes 188-191 are zero
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* after list-directed-IPL and ccw-IPL.
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*/
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void write_subsystem_identification(void)
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{
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struct subchannel_id *schid = (struct subchannel_id *) 184;
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uint32_t *zeroes = (uint32_t *) 188;
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*schid = blk_schid;
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*zeroes = 0;
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}
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void virtio_panic(const char *string)
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{
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sclp_print(string);
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disabled_wait();
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while (1) { }
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}
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static bool find_dev(struct schib *schib, int dev_no)
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{
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int i, r;
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for (i = 0; i < 0x10000; i++) {
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blk_schid.sch_no = i;
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r = stsch_err(blk_schid, schib);
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if ((r == 3) || (r == -EIO)) {
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break;
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}
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if (!schib->pmcw.dnv) {
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continue;
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}
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if (!virtio_is_blk(blk_schid)) {
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continue;
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}
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if ((dev_no < 0) || (schib->pmcw.dev == dev_no)) {
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return true;
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}
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}
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return false;
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}
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static void virtio_setup(uint64_t dev_info)
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{
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struct schib schib;
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int ssid;
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bool found = false;
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uint16_t dev_no;
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/*
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* We unconditionally enable mss support. In every sane configuration,
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* this will succeed; and even if it doesn't, stsch_err() can deal
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* with the consequences.
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*/
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enable_mss_facility();
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if (dev_info != -1) {
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dev_no = dev_info & 0xffff;
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debug_print_int("device no. ", dev_no);
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blk_schid.ssid = (dev_info >> 16) & 0x3;
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debug_print_int("ssid ", blk_schid.ssid);
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found = find_dev(&schib, dev_no);
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} else {
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for (ssid = 0; ssid < 0x3; ssid++) {
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blk_schid.ssid = ssid;
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found = find_dev(&schib, -1);
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if (found) {
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break;
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}
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}
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}
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if (!found) {
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virtio_panic("No virtio-blk device found!\n");
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}
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virtio_setup_block(blk_schid);
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if (!virtio_ipl_disk_is_valid()) {
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virtio_panic("No valid hard disk detected.\n");
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}
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}
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int main(void)
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{
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sclp_setup();
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debug_print_int("boot reg[7] ", boot_value);
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virtio_setup(boot_value);
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zipl_load(); /* no return */
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virtio_panic("Failed to load OS from hard disk\n");
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return 0; /* make compiler happy */
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}
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