diff options
Diffstat (limited to 'arch/powerpc/purgatory')
| -rw-r--r-- | arch/powerpc/purgatory/.gitignore | 3 | ||||
| -rw-r--r-- | arch/powerpc/purgatory/Makefile | 23 | ||||
| -rw-r--r-- | arch/powerpc/purgatory/trampoline_64.S | 163 |
3 files changed, 189 insertions, 0 deletions
diff --git a/arch/powerpc/purgatory/.gitignore b/arch/powerpc/purgatory/.gitignore new file mode 100644 index 000000000..b8dc6ff34 --- /dev/null +++ b/arch/powerpc/purgatory/.gitignore @@ -0,0 +1,3 @@ +# SPDX-License-Identifier: GPL-2.0-only +kexec-purgatory.c +purgatory.ro diff --git a/arch/powerpc/purgatory/Makefile b/arch/powerpc/purgatory/Makefile new file mode 100644 index 000000000..d08239ae2 --- /dev/null +++ b/arch/powerpc/purgatory/Makefile @@ -0,0 +1,23 @@ +# SPDX-License-Identifier: GPL-2.0 + +KASAN_SANITIZE := n + +targets += trampoline_$(BITS).o purgatory.ro kexec-purgatory.c + +# When profile-guided optimization is enabled, llvm emits two different +# overlapping text sections, which is not supported by kexec. Remove profile +# optimization flags. +KBUILD_CFLAGS := $(filter-out -fprofile-sample-use=% -fprofile-use=%,$(KBUILD_CFLAGS)) + +LDFLAGS_purgatory.ro := -e purgatory_start -r --no-undefined + +$(obj)/purgatory.ro: $(obj)/trampoline_$(BITS).o FORCE + $(call if_changed,ld) + +quiet_cmd_bin2c = BIN2C $@ + cmd_bin2c = $(objtree)/scripts/bin2c kexec_purgatory < $< > $@ + +$(obj)/kexec-purgatory.c: $(obj)/purgatory.ro FORCE + $(call if_changed,bin2c) + +obj-y += kexec-purgatory.o diff --git a/arch/powerpc/purgatory/trampoline_64.S b/arch/powerpc/purgatory/trampoline_64.S new file mode 100644 index 000000000..d956b8a35 --- /dev/null +++ b/arch/powerpc/purgatory/trampoline_64.S @@ -0,0 +1,163 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * kexec trampoline + * + * Based on code taken from kexec-tools and kexec-lite. + * + * Copyright (C) 2004 - 2005, Milton D Miller II, IBM Corporation + * Copyright (C) 2006, Mohan Kumar M, IBM Corporation + * Copyright (C) 2013, Anton Blanchard, IBM Corporation + */ + +#include <asm/asm-compat.h> +#include <asm/crashdump-ppc64.h> + + .machine ppc64 + .balign 256 + .globl purgatory_start +purgatory_start: + b master + + /* ABI: possible run_at_load flag at 0x5c */ + .org purgatory_start + 0x5c + .globl run_at_load +run_at_load: + .long 0 + .size run_at_load, . - run_at_load + + /* ABI: slaves start at 60 with r3=phys */ + .org purgatory_start + 0x60 +slave: + b . + /* ABI: end of copied region */ + .org purgatory_start + 0x100 + .size purgatory_start, . - purgatory_start + +/* + * The above 0x100 bytes at purgatory_start are replaced with the + * code from the kernel (or next stage) by setup_purgatory(). + */ + +master: + or %r1,%r1,%r1 /* low priority to let other threads catchup */ + isync + mr %r17,%r3 /* save cpu id to r17 */ + mr %r15,%r4 /* save physical address in reg15 */ + + /* Work out where we're running */ + bcl 20, 31, 0f +0: mflr %r18 + + /* + * Copy BACKUP_SRC_SIZE bytes from BACKUP_SRC_START to + * backup_start 8 bytes at a time. + * + * Use r3 = dest, r4 = src, r5 = size, r6 = count + */ + ld %r3, (backup_start - 0b)(%r18) + cmpdi %cr0, %r3, 0 + beq .Lskip_copy /* skip if there is no backup region */ + lis %r5, BACKUP_SRC_SIZE@h + ori %r5, %r5, BACKUP_SRC_SIZE@l + cmpdi %cr0, %r5, 0 + beq .Lskip_copy /* skip if copy size is zero */ + lis %r4, BACKUP_SRC_START@h + ori %r4, %r4, BACKUP_SRC_START@l + li %r6, 0 +.Lcopy_loop: + ldx %r0, %r6, %r4 + stdx %r0, %r6, %r3 + addi %r6, %r6, 8 + cmpld %cr0, %r6, %r5 + blt .Lcopy_loop + +.Lskip_copy: + or %r3,%r3,%r3 /* ok now to high priority, lets boot */ + lis %r6,0x1 + mtctr %r6 /* delay a bit for slaves to catch up */ + bdnz . /* before we overwrite 0-100 again */ + + /* load device-tree address */ + ld %r3, (dt_offset - 0b)(%r18) + mr %r16,%r3 /* save dt address in reg16 */ + li %r4,20 + LWZX_BE %r6,%r3,%r4 /* fetch __be32 version number at byte 20 */ + cmpwi %cr0,%r6,2 /* v2 or later? */ + blt 1f + li %r4,28 + STWX_BE %r17,%r3,%r4 /* Store my cpu as __be32 at byte 28 */ +1: + /* Load opal base and entry values in r8 & r9 respectively */ + ld %r8,(opal_base - 0b)(%r18) + ld %r9,(opal_entry - 0b)(%r18) + + /* load the kernel address */ + ld %r4,(kernel - 0b)(%r18) + + /* load the run_at_load flag */ + /* possibly patched by kexec */ + ld %r6,(run_at_load - 0b)(%r18) + /* and patch it into the kernel */ + stw %r6,(0x5c)(%r4) + + mr %r3,%r16 /* restore dt address */ + + li %r5,0 /* r5 will be 0 for kernel */ + + mfmsr %r11 + andi. %r10,%r11,1 /* test MSR_LE */ + bne .Little_endian + + mtctr %r4 /* prepare branch to */ + bctr /* start kernel */ + +.Little_endian: + mtsrr0 %r4 /* prepare branch to */ + + clrrdi %r11,%r11,1 /* clear MSR_LE */ + mtsrr1 %r11 + + rfid /* update MSR and start kernel */ + + .balign 8 + .globl kernel +kernel: + .8byte 0x0 + .size kernel, . - kernel + + .balign 8 + .globl dt_offset +dt_offset: + .8byte 0x0 + .size dt_offset, . - dt_offset + + .balign 8 + .globl backup_start +backup_start: + .8byte 0x0 + .size backup_start, . - backup_start + + .balign 8 + .globl opal_base +opal_base: + .8byte 0x0 + .size opal_base, . - opal_base + + .balign 8 + .globl opal_entry +opal_entry: + .8byte 0x0 + .size opal_entry, . - opal_entry + + .data + .balign 8 +.globl purgatory_sha256_digest +purgatory_sha256_digest: + .skip 32 + .size purgatory_sha256_digest, . - purgatory_sha256_digest + + .balign 8 +.globl purgatory_sha_regions +purgatory_sha_regions: + .skip 8 * 2 * 16 + .size purgatory_sha_regions, . - purgatory_sha_regions |