diff options
Diffstat (limited to '')
-rw-r--r-- | arch/powerpc/platforms/powernv/subcore-asm.S | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/powernv/subcore-asm.S b/arch/powerpc/platforms/powernv/subcore-asm.S new file mode 100644 index 000000000..e038f6761 --- /dev/null +++ b/arch/powerpc/platforms/powernv/subcore-asm.S @@ -0,0 +1,91 @@ +/* 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 |