/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* Copyright 2013, Michael (Ellerman|Neuling), IBM Corporation.
*/
#include <asm/asm-offsets.h>
#include <asm/ppc_asm.h>
#include <asm/reg.h>
#include "subcore.h"
_GLOBAL(split_core_secondary_loop)
/*
* r3 = u8 *state, used throughout the routine
* r4 = temp
* r5 = temp
* ..
* r12 = MSR
*/
mfmsr r12
/* Disable interrupts so SRR0/1 don't get trashed */
li r4,0
ori r4,r4,MSR_EE|MSR_SE|MSR_BE|MSR_RI
andc r4,r12,r4
sync
mtmsrd r4
/* Switch to real mode and leave interrupts off */
li r5, MSR_IR|MSR_DR
andc r5, r4, r5
LOAD_REG_ADDR(r4, real_mode)
mtspr SPRN_SRR0,r4
mtspr SPRN_SRR1,r5
rfid
b . /* prevent speculative execution */
real_mode:
/* Grab values from unsplit SPRs */
mfspr r6, SPRN_LDBAR
mfspr r7, SPRN_PMMAR
mfspr r8, SPRN_PMCR
mfspr r9, SPRN_RPR
mfspr r10, SPRN_SDR1
/* Order reading the SPRs vs telling the primary we are ready to split */
sync
/* Tell thread 0 we are in real mode */
li r4, SYNC_STEP_REAL_MODE
stb r4, 0(r3)
li r5, (HID0_POWER8_4LPARMODE | HID0_POWER8_2LPARMODE)@highest
sldi r5, r5, 48
/* Loop until we see the split happen in HID0 */
1: mfspr r4, SPRN_HID0
and. r4, r4, r5
beq 1b
/*
* We only need to initialise the below regs once for each subcore,
* but it's simpler and harmless to do it on each thread.
*/
/* Make sure various SPRS have sane values */
li r4, 0
mtspr SPRN_LPID, r4
mtspr SPRN_PCR, r4
mtspr SPRN_HDEC, r4
/* Restore SPR values now we are split */
mtspr SPRN_LDBAR, r6
mtspr SPRN_PMMAR, r7
mtspr SPRN_PMCR, r8
mtspr SPRN_RPR, r9
mtspr SPRN_SDR1, r10
LOAD_REG_ADDR(r5, virtual_mode)
/* Get out of real mode */
mtspr SPRN_SRR0,r5
mtspr SPRN_SRR1,r12
rfid
b . /* prevent speculative execution */
virtual_mode:
blr
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