Re: [PATCH] pc-bios/s390x: Pack ResetInfo struct

["Jason J. Herne" <jjherne@linux.ibm.com>]

On 2/7/20 6:28 AM, Christian Borntraeger wrote:
> Jason,
> 
> can you run objdump -Sdr on jump2ipl.o on a broken variant?
> 
> 
To keep the volume lower, I've only pasted the output that I think you're interested in. 
If you want to see the entire thing just let me know.

static void jump_to_IPL_2(void)
{
  1d0:	eb bf f0 58 00 24 	stmg	%r11,%r15,88(%r15)
  1d6:	a7 fb ff 50       	aghi	%r15,-176
  1da:	b9 04 00 bf       	lgr	%r11,%r15
     ResetInfo *current = 0;
  1de:	a7 19 00 00       	lghi	%r1,0
  1e2:	e3 10 b0 a8 00 24 	stg	%r1,168(%r11)

     void (*ipl)(void) = (void *) (uint64_t) current->ipl_continue;
  1e8:	e3 10 b0 a8 00 04 	lg	%r1,168(%r11)
  1ee:	58 10 10 08       	l	%r1,8(%r1)
  1f2:	b9 16 00 11       	llgfr	%r1,%r1
  1f6:	e3 10 b0 a0 00 24 	stg	%r1,160(%r11)
     *current = save;
  1fc:	e3 10 b0 a8 00 04 	lg	%r1,168(%r11)
  202:	c0 20 00 00 00 00 	larl	%r2,202 <jump_to_IPL_2+0x32>
			204: R_390_PC32DBL	.bss+0x2
  208:	eb 23 20 00 00 04 	lmg	%r2,%r3,0(%r2)
  20e:	eb 23 10 00 00 24 	stmg	%r2,%r3,0(%r1)
     ipl(); /* should not return */
  214:	e3 10 b0 a0 00 04 	lg	%r1,160(%r11)
  21a:	0d e1             	basr	%r14,%r1
}
  21c:	18 00             	lr	%r0,%r0
  21e:	eb bf b1 08 00 04 	lmg	%r11,%r15,264(%r11)
  224:	07 fe             	br	%r14
  226:	07 07             	nopr	%r7

0000000000000228 <jump_to_IPL_code>:

void jump_to_IPL_code(uint64_t address)
{
  228:	eb bf f0 58 00 24 	stmg	%r11,%r15,88(%r15)
  22e:	c0 d0 00 00 00 00 	larl	%r13,22e <jump_to_IPL_code+0x6>
			230: R_390_PC32DBL	.rodata+0x2a
  234:	a7 fb ff 50       	aghi	%r15,-176
  238:	b9 04 00 bf       	lgr	%r11,%r15
  23c:	e3 20 b0 a0 00 24 	stg	%r2,160(%r11)
     /* store the subsystem information _after_ the bootmap was loaded */
     write_subsystem_identification();
  242:	c0 e5 00 00 00 00 	brasl	%r14,242 <jump_to_IPL_code+0x1a>
			244: R_390_PLT32DBL	write_subsystem_identification+0x2

     /* prevent unknown IPL types in the guest */
     if (iplb.pbt == S390_IPL_TYPE_QEMU_SCSI) {
  248:	c0 10 00 00 00 00 	larl	%r1,248 <jump_to_IPL_code+0x20>
			24a: R_390_GOTENT	iplb+0x2
  24e:	e3 10 10 00 00 04 	lg	%r1,0(%r1)
  254:	43 10 10 0c       	ic	%r1,12(%r1)
  258:	a7 28 00 ff       	lhi	%r2,255
  25c:	14 12             	nr	%r1,%r2
  25e:	a7 1e 00 ff       	chi	%r1,255
  262:	a7 74 00 15       	jne	28c <jump_to_IPL_code+0x64>
         iplb.pbt = S390_IPL_TYPE_CCW;
  266:	c0 10 00 00 00 00 	larl	%r1,266 <jump_to_IPL_code+0x3e>
			268: R_390_GOTENT	iplb+0x2
  26c:	e3 10 10 00 00 04 	lg	%r1,0(%r1)
  272:	92 02 10 0c       	mvi	12(%r1),2
         set_iplb(&iplb);
  276:	c0 10 00 00 00 00 	larl	%r1,276 <jump_to_IPL_code+0x4e>
			278: R_390_GOTENT	iplb+0x2
  27c:	e3 10 10 00 00 04 	lg	%r1,0(%r1)
  282:	b9 04 00 21       	lgr	%r2,%r1
  286:	c0 e5 ff ff ff 75 	brasl	%r14,170 <set_iplb>
     /*
      * The IPL PSW is at address 0. We also must not overwrite the
      * content of non-BIOS memory after we loaded the guest, so we
      * save the original content and restore it in jump_to_IPL_2.
      */
     ResetInfo *current = 0;
  28c:	a7 19 00 00       	lghi	%r1,0
  290:	e3 10 b0 a8 00 24 	stg	%r1,168(%r11)

     save = *current;
  296:	c0 10 00 00 00 00 	larl	%r1,296 <jump_to_IPL_code+0x6e>
			298: R_390_PC32DBL	.bss+0x2
  29c:	e3 20 b0 a8 00 04 	lg	%r2,168(%r11)
  2a2:	eb 23 20 00 00 04 	lmg	%r2,%r3,0(%r2)
  2a8:	eb 23 10 00 00 24 	stmg	%r2,%r3,0(%r1)

     current->ipl_psw = (uint64_t) &jump_to_IPL_2;
  2ae:	c0 20 ff ff ff 91 	larl	%r2,1d0 <jump_to_IPL_2>
  2b4:	e3 10 b0 a8 00 04 	lg	%r1,168(%r11)
  2ba:	e3 20 10 00 00 24 	stg	%r2,0(%r1)
     current->ipl_psw |= RESET_PSW_MASK;
  2c0:	e3 10 b0 a8 00 04 	lg	%r1,168(%r11)
  2c6:	e3 10 10 00 00 04 	lg	%r1,0(%r1)
  2cc:	e3 20 d0 00 00 04 	lg	%r2,0(%r13)
  2d2:	b9 81 00 21       	ogr	%r2,%r1
  2d6:	e3 10 b0 a8 00 04 	lg	%r1,168(%r11)
  2dc:	e3 20 10 00 00 24 	stg	%r2,0(%r1)
     current->ipl_continue = address & 0x7fffffff;
  2e2:	e3 10 b0 a0 00 04 	lg	%r1,160(%r11)
  2e8:	b9 17 00 21       	llgtr	%r2,%r1
  2ec:	e3 10 b0 a8 00 04 	lg	%r1,168(%r11)
  2f2:	50 20 10 08       	st	%r2,8(%r1)

     debug_print_int("set IPL addr to", current->ipl_continue);
  2f6:	e3 10 b0 a8 00 04 	lg	%r1,168(%r11)
  2fc:	58 10 10 08       	l	%r1,8(%r1)
  300:	b9 16 00 11       	llgfr	%r1,%r1
  304:	b9 04 00 31       	lgr	%r3,%r1
  308:	c0 20 00 00 00 00 	larl	%r2,308 <jump_to_IPL_code+0xe0>
			30a: R_390_PC32DBL	.rodata+0x2
  30e:	c0 e5 ff ff ff 4d 	brasl	%r14,1a8 <debug_print_int>

     /* Ensure the guest output starts fresh */
     sclp_print("\n");
  314:	c0 20 00 00 00 00 	larl	%r2,314 <jump_to_IPL_code+0xec>
			316: R_390_PC32DBL	.rodata+0x12
  31a:	c0 e5 00 00 00 00 	brasl	%r14,31a <jump_to_IPL_code+0xf2>
			31c: R_390_PLT32DBL	sclp_print+0x2
     /*
      * HACK ALERT.
      * We use the load normal reset to keep r15 unchanged. jump_to_IPL_2
      * can then use r15 as its stack pointer.
      */
     asm volatile("lghi 1,1\n\t"
  320:	a7 19 00 01       	lghi	%r1,1
  324:	83 11 03 08       	diag	%r1,%r1,776
                  "diag 1,1,0x308\n\t"
                  : : : "1", "memory");
     panic("\n! IPL returns !\n");
  328:	c0 20 00 00 00 00 	larl	%r2,328 <jump_to_IPL_code+0x100>
			32a: R_390_PC32DBL	.rodata+0x14
  32e:	c0 e5 00 00 00 00 	brasl	%r14,32e <jump_to_IPL_code+0x106>
			330: R_390_PLT32DBL	panic+0x2
}
  334:	18 00             	lr	%r0,%r0
  336:	eb bf b1 08 00 04 	lmg	%r11,%r15,264(%r11)
  33c:	07 fe             	br	%r14
  33e:	07 07             	nopr	%r7



-- 
-- Jason J. Herne (jjherne@linux.ibm.com)