55a5542a54
The resume code checks if the resume cpu is the same as the suspend cpu. If not, and if it is also not possible to switch to the suspend cpu, an error message should be printed and the resume process should be stopped by loading a disabled wait psw. The current logic is broken in multiple ways, the message is never printed, and the disabled wait psw never loaded because the kernel panics before that: - sam31 and SIGP_SET_ARCHITECTURE to ESA mode is wrong, this will break on the first 64bit instruction in sclp_early_printk(). - The init stack should be used, but the stack pointer is not set up correctly (missing aghi %r15,-STACK_FRAME_OVERHEAD). - __sclp_early_printk() checks the sclp_init_state. If it is not sclp_init_state_uninitialized, it simply returns w/o printing anything. In the resumed kernel however, sclp_init_state will never be uninitialized. This patch fixes those issues by removing the sam31/ESA logic, adding a correct init stack pointer, and also introducing sclp_early_printk_force() to allow using sclp_early_printk() even when sclp_init_state is not uninitialized. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
287 lines
6.7 KiB
ArmAsm
287 lines
6.7 KiB
ArmAsm
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* S390 64-bit swsusp implementation
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*
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* Copyright IBM Corp. 2009
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*
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* Author(s): Hans-Joachim Picht <hans@linux.vnet.ibm.com>
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* Michael Holzheu <holzheu@linux.vnet.ibm.com>
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*/
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#include <linux/linkage.h>
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#include <asm/page.h>
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#include <asm/ptrace.h>
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#include <asm/thread_info.h>
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#include <asm/asm-offsets.h>
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#include <asm/nospec-insn.h>
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#include <asm/sigp.h>
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/*
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* Save register context in absolute 0 lowcore and call swsusp_save() to
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* create in-memory kernel image. The context is saved in the designated
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* "store status" memory locations (see POP).
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* We return from this function twice. The first time during the suspend to
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* disk process. The second time via the swsusp_arch_resume() function
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* (see below) in the resume process.
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* This function runs with disabled interrupts.
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*/
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GEN_BR_THUNK %r14
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.section .text
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ENTRY(swsusp_arch_suspend)
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stmg %r6,%r15,__SF_GPRS(%r15)
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lgr %r1,%r15
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aghi %r15,-STACK_FRAME_OVERHEAD
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stg %r1,__SF_BACKCHAIN(%r15)
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/* Store FPU registers */
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brasl %r14,save_fpu_regs
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/* Deactivate DAT */
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stnsm __SF_EMPTY(%r15),0xfb
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/* Store prefix register on stack */
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stpx __SF_EMPTY(%r15)
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/* Save prefix register contents for lowcore copy */
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llgf %r10,__SF_EMPTY(%r15)
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/* Get pointer to save area */
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lghi %r1,0x1000
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/* Save CPU address */
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stap __LC_EXT_CPU_ADDR(%r0)
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/* Store registers */
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mvc 0x318(4,%r1),__SF_EMPTY(%r15) /* move prefix to lowcore */
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stam %a0,%a15,0x340(%r1) /* store access registers */
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stctg %c0,%c15,0x380(%r1) /* store control registers */
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stmg %r0,%r15,0x280(%r1) /* store general registers */
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stpt 0x328(%r1) /* store timer */
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stck __SF_EMPTY(%r15) /* store clock */
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stckc 0x330(%r1) /* store clock comparator */
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/* Update cputime accounting before going to sleep */
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lg %r0,__LC_LAST_UPDATE_TIMER
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slg %r0,0x328(%r1)
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alg %r0,__LC_SYSTEM_TIMER
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stg %r0,__LC_SYSTEM_TIMER
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mvc __LC_LAST_UPDATE_TIMER(8),0x328(%r1)
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lg %r0,__LC_LAST_UPDATE_CLOCK
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slg %r0,__SF_EMPTY(%r15)
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alg %r0,__LC_STEAL_TIMER
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stg %r0,__LC_STEAL_TIMER
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mvc __LC_LAST_UPDATE_CLOCK(8),__SF_EMPTY(%r15)
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/* Activate DAT */
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stosm __SF_EMPTY(%r15),0x04
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/* Set prefix page to zero */
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xc __SF_EMPTY(4,%r15),__SF_EMPTY(%r15)
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spx __SF_EMPTY(%r15)
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/* Save absolute zero pages */
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larl %r2,suspend_zero_pages
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lg %r2,0(%r2)
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lghi %r4,0
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lghi %r3,2*PAGE_SIZE
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lghi %r5,2*PAGE_SIZE
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1: mvcle %r2,%r4,0
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jo 1b
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/* Copy lowcore to absolute zero lowcore */
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lghi %r2,0
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lgr %r4,%r10
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lghi %r3,2*PAGE_SIZE
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lghi %r5,2*PAGE_SIZE
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1: mvcle %r2,%r4,0
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jo 1b
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/* Save image */
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brasl %r14,swsusp_save
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/* Restore prefix register and return */
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lghi %r1,0x1000
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spx 0x318(%r1)
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lmg %r6,%r15,STACK_FRAME_OVERHEAD + __SF_GPRS(%r15)
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lghi %r2,0
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BR_EX %r14
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/*
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* Restore saved memory image to correct place and restore register context.
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* Then we return to the function that called swsusp_arch_suspend().
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* swsusp_arch_resume() runs with disabled interrupts.
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*/
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ENTRY(swsusp_arch_resume)
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stmg %r6,%r15,__SF_GPRS(%r15)
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lgr %r1,%r15
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aghi %r15,-STACK_FRAME_OVERHEAD
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stg %r1,__SF_BACKCHAIN(%r15)
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/* Make all free pages stable */
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lghi %r2,1
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brasl %r14,arch_set_page_states
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/* Deactivate DAT */
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stnsm __SF_EMPTY(%r15),0xfb
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/* Set prefix page to zero */
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xc __SF_EMPTY(4,%r15),__SF_EMPTY(%r15)
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spx __SF_EMPTY(%r15)
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/* Restore saved image */
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larl %r1,restore_pblist
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lg %r1,0(%r1)
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ltgr %r1,%r1
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jz 2f
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0:
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lg %r2,8(%r1)
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lg %r4,0(%r1)
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iske %r0,%r4
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lghi %r3,PAGE_SIZE
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lghi %r5,PAGE_SIZE
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1:
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mvcle %r2,%r4,0
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jo 1b
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lg %r2,8(%r1)
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sske %r0,%r2
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lg %r1,16(%r1)
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ltgr %r1,%r1
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jnz 0b
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2:
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ptlb /* flush tlb */
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/* Reset System */
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larl %r1,restart_entry
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larl %r2,.Lrestart_diag308_psw
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og %r1,0(%r2)
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stg %r1,0(%r0)
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larl %r1,.Lnew_pgm_check_psw
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epsw %r2,%r3
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stm %r2,%r3,0(%r1)
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mvc __LC_PGM_NEW_PSW(16,%r0),0(%r1)
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lghi %r0,0
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diag %r0,%r0,0x308
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restart_entry:
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lhi %r1,1
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sigp %r1,%r0,SIGP_SET_ARCHITECTURE
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sam64
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#ifdef CONFIG_SMP
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larl %r1,smp_cpu_mt_shift
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icm %r1,15,0(%r1)
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jz smt_done
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llgfr %r1,%r1
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smt_loop:
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sigp %r1,%r0,SIGP_SET_MULTI_THREADING
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brc 8,smt_done /* accepted */
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brc 2,smt_loop /* busy, try again */
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smt_done:
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#endif
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larl %r1,.Lnew_pgm_check_psw
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lpswe 0(%r1)
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pgm_check_entry:
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/* Switch to original suspend CPU */
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larl %r1,.Lresume_cpu /* Resume CPU address: r2 */
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stap 0(%r1)
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llgh %r2,0(%r1)
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llgh %r1,__LC_EXT_CPU_ADDR(%r0) /* Suspend CPU address: r1 */
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cgr %r1,%r2
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je restore_registers /* r1 = r2 -> nothing to do */
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larl %r4,.Lrestart_suspend_psw /* Set new restart PSW */
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mvc __LC_RST_NEW_PSW(16,%r0),0(%r4)
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3:
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sigp %r9,%r1,SIGP_INITIAL_CPU_RESET /* sigp initial cpu reset */
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brc 8,4f /* accepted */
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brc 2,3b /* busy, try again */
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/* Suspend CPU not available -> panic */
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larl %r15,init_thread_union
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aghi %r15,1<<(PAGE_SHIFT+THREAD_SIZE_ORDER)
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aghi %r15,-STACK_FRAME_OVERHEAD
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larl %r2,.Lpanic_string
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brasl %r14,sclp_early_printk_force
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larl %r3,.Ldisabled_wait_31
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lpsw 0(%r3)
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4:
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/* Switch to suspend CPU */
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sigp %r9,%r1,SIGP_RESTART /* sigp restart to suspend CPU */
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brc 2,4b /* busy, try again */
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5:
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sigp %r9,%r2,SIGP_STOP /* sigp stop to current resume CPU */
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brc 2,5b /* busy, try again */
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6: j 6b
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restart_suspend:
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larl %r1,.Lresume_cpu
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llgh %r2,0(%r1)
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7:
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sigp %r9,%r2,SIGP_SENSE /* sigp sense, wait for resume CPU */
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brc 8,7b /* accepted, status 0, still running */
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brc 2,7b /* busy, try again */
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tmll %r9,0x40 /* Test if resume CPU is stopped */
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jz 7b
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restore_registers:
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/* Restore registers */
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lghi %r13,0x1000 /* %r1 = pointer to save area */
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/* Ignore time spent in suspended state. */
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llgf %r1,0x318(%r13)
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stck __LC_LAST_UPDATE_CLOCK(%r1)
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spt 0x328(%r13) /* reprogram timer */
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//sckc 0x330(%r13) /* set clock comparator */
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lctlg %c0,%c15,0x380(%r13) /* load control registers */
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lam %a0,%a15,0x340(%r13) /* load access registers */
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/* Load old stack */
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lg %r15,0x2f8(%r13)
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/* Save prefix register */
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mvc __SF_EMPTY(4,%r15),0x318(%r13)
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/* Restore absolute zero pages */
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lghi %r2,0
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larl %r4,suspend_zero_pages
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lg %r4,0(%r4)
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lghi %r3,2*PAGE_SIZE
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lghi %r5,2*PAGE_SIZE
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1: mvcle %r2,%r4,0
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jo 1b
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/* Restore prefix register */
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spx __SF_EMPTY(%r15)
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/* Activate DAT */
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stosm __SF_EMPTY(%r15),0x04
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/* Make all free pages unstable */
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lghi %r2,0
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brasl %r14,arch_set_page_states
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/* Call arch specific early resume code */
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brasl %r14,s390_early_resume
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/* Return 0 */
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lmg %r6,%r15,STACK_FRAME_OVERHEAD + __SF_GPRS(%r15)
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lghi %r2,0
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BR_EX %r14
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.section .data..nosave,"aw",@progbits
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.align 8
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.Ldisabled_wait_31:
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.long 0x000a0000,0x00000000
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.Lpanic_string:
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.asciz "Resume not possible because suspend CPU is no longer available\n"
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.align 8
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.Lrestart_diag308_psw:
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.long 0x00080000,0x80000000
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.Lrestart_suspend_psw:
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.quad 0x0000000180000000,restart_suspend
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.Lnew_pgm_check_psw:
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.quad 0,pgm_check_entry
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.Lresume_cpu:
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.byte 0,0
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