455e3bc3f7
Because virtio-scsi type devices use a non-architected IPLB pbt code they cannot be set and stored normally. Instead, the IPLB must be rebuilt during re-ipl. As s390x does not natively support multiple boot devices, the devno field is used to store the position in the boot order for the device. Handling the rebuild as part of DIAG308 removes the need to check the devices for invalid IPLBs later in the IPL. Signed-off-by: Jared Rossi <jrossi@linux.ibm.com> Acked-by: Thomas Huth <thuth@redhat.com> Message-ID: <20241020012953.1380075-17-jrossi@linux.ibm.com> Signed-off-by: Thomas Huth <thuth@redhat.com>
105 lines
3.0 KiB
C
105 lines
3.0 KiB
C
/*
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* QEMU s390-ccw firmware - jump to IPL code
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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 <string.h>
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#include <stdio.h>
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#include "s390-ccw.h"
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#include "s390-arch.h"
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#define KERN_IMAGE_START 0x010000UL
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#define RESET_PSW_MASK (PSW_MASK_SHORTPSW | PSW_MASK_64)
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#define RESET_PSW ((uint64_t)&jump_to_IPL_addr | RESET_PSW_MASK)
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static uint64_t *reset_psw = 0, save_psw, ipl_continue;
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void write_reset_psw(uint64_t psw)
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{
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*reset_psw = psw;
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}
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static void jump_to_IPL_addr(void)
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{
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__attribute__((noreturn)) void (*ipl)(void) = (void *)ipl_continue;
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/* Restore reset PSW */
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write_reset_psw(save_psw);
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ipl();
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/* should not return */
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}
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int jump_to_IPL_code(uint64_t address)
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{
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/* store the subsystem information _after_ the bootmap was loaded */
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write_subsystem_identification();
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write_iplb_location();
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/*
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* The IPLB for QEMU SCSI type devices must be rebuilt during re-ipl. The
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* iplb.devno is set to the boot position of the target SCSI device.
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*/
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if (iplb.pbt == S390_IPL_TYPE_QEMU_SCSI) {
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iplb.devno = qipl.index;
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if (!set_iplb(&iplb)) {
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panic("Failed to set IPLB");
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}
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}
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/*
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* The IPL PSW is at address 0. We also must not overwrite the
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* content of non-BIOS memory after we loaded the guest, so we
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* save the original content and restore it in jump_to_IPL_2.
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*/
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if (address) {
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save_psw = *reset_psw;
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write_reset_psw(RESET_PSW);
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ipl_continue = address;
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}
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debug_print_int("set IPL addr to", address ?: *reset_psw & PSW_MASK_SHORT_ADDR);
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/* Ensure the guest output starts fresh */
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printf("\n");
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/*
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* HACK ALERT.
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* We use the load normal reset to keep r15 unchanged. jump_to_IPL_2
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* can then use r15 as its stack pointer.
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*/
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asm volatile("lghi %%r1,1\n\t"
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"diag %%r1,%%r1,0x308\n\t"
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: : : "1", "memory");
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puts("IPL code jump failed");
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return -1;
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}
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void jump_to_low_kernel(void)
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{
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/*
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* If it looks like a Linux binary, i.e. there is the "S390EP" magic from
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* arch/s390/kernel/head.S here, then let's jump to the well-known Linux
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* kernel start address (when jumping to the PSW-at-zero address instead,
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* the kernel startup code fails when we booted from a network device).
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*/
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if (!memcmp((char *)S390EP, "S390EP", 6)) {
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jump_to_IPL_code(KERN_IMAGE_START);
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}
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/* Trying to get PSW at zero address (pointed to by reset_psw) */
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if (*reset_psw & RESET_PSW_MASK) {
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/*
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* Surely nobody will try running directly from lowcore, so
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* let's use 0 as an indication that we want to load the reset
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* psw at 0x0 and not jump to the entry.
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*/
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jump_to_IPL_code(0);
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}
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/* No other option left, so use the Linux kernel start address */
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jump_to_IPL_code(KERN_IMAGE_START);
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}
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