From 0d97631392c24a9573dafb7b6962cc40b5ef2281 Mon Sep 17 00:00:00 2001 From: Thiago Jung Bauermann Date: Tue, 29 Nov 2016 23:45:52 +1100 Subject: [PATCH] powerpc: Add purgatory for kexec_file_load() implementation. This purgatory implementation is based on the versions from kexec-tools and kexec-lite, with additional changes. Signed-off-by: Thiago Jung Bauermann Signed-off-by: Michael Ellerman --- arch/powerpc/Makefile | 1 + arch/powerpc/kernel/machine_kexec_64.c | 2 +- arch/powerpc/purgatory/.gitignore | 2 + arch/powerpc/purgatory/Makefile | 15 +++ arch/powerpc/purgatory/trampoline.S | 128 +++++++++++++++++++++++++ 5 files changed, 147 insertions(+), 1 deletion(-) create mode 100644 arch/powerpc/purgatory/.gitignore create mode 100644 arch/powerpc/purgatory/Makefile create mode 100644 arch/powerpc/purgatory/trampoline.S diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile index 82ce8c8b63ad..31286fa7873c 100644 --- a/arch/powerpc/Makefile +++ b/arch/powerpc/Makefile @@ -250,6 +250,7 @@ core-y += arch/powerpc/kernel/ \ core-$(CONFIG_XMON) += arch/powerpc/xmon/ core-$(CONFIG_KVM) += arch/powerpc/kvm/ core-$(CONFIG_PERF_EVENTS) += arch/powerpc/perf/ +core-$(CONFIG_KEXEC_FILE) += arch/powerpc/purgatory/ drivers-$(CONFIG_OPROFILE) += arch/powerpc/oprofile/ diff --git a/arch/powerpc/kernel/machine_kexec_64.c b/arch/powerpc/kernel/machine_kexec_64.c index a205fa3d9bf3..5c12e21d0d1a 100644 --- a/arch/powerpc/kernel/machine_kexec_64.c +++ b/arch/powerpc/kernel/machine_kexec_64.c @@ -310,7 +310,7 @@ void default_machine_kexec(struct kimage *image) if (!kdump_in_progress()) kexec_prepare_cpus(); - pr_debug("kexec: Starting switchover sequence.\n"); + printk("kexec: Starting switchover sequence.\n"); /* switch to a staticly allocated stack. Based on irq stack code. * We setup preempt_count to avoid using VMX in memcpy. diff --git a/arch/powerpc/purgatory/.gitignore b/arch/powerpc/purgatory/.gitignore new file mode 100644 index 000000000000..e9e66f178a6d --- /dev/null +++ b/arch/powerpc/purgatory/.gitignore @@ -0,0 +1,2 @@ +kexec-purgatory.c +purgatory.ro diff --git a/arch/powerpc/purgatory/Makefile b/arch/powerpc/purgatory/Makefile new file mode 100644 index 000000000000..ac8793c13348 --- /dev/null +++ b/arch/powerpc/purgatory/Makefile @@ -0,0 +1,15 @@ +targets += trampoline.o purgatory.ro kexec-purgatory.c + +LDFLAGS_purgatory.ro := -e purgatory_start -r --no-undefined + +$(obj)/purgatory.ro: $(obj)/trampoline.o FORCE + $(call if_changed,ld) + +CMD_BIN2C = $(objtree)/scripts/basic/bin2c +quiet_cmd_bin2c = BIN2C $@ + cmd_bin2c = $(CMD_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.S b/arch/powerpc/purgatory/trampoline.S new file mode 100644 index 000000000000..f9760ccf4032 --- /dev/null +++ b/arch/powerpc/purgatory/trampoline.S @@ -0,0 +1,128 @@ +/* + * 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 + * + * This program is free software; you can redistribute it and/or modify it under + * the terms of the GNU General Public License as published by the Free + * Software Foundation (version 2 of the License). + */ + +#if defined(__LITTLE_ENDIAN__) +#define STWX_BE stwbrx +#define LWZX_BE lwbrx +#elif defined(__BIG_ENDIAN__) +#define STWX_BE stwx +#define LWZX_BE lwzx +#else +#error no endianness defined! +#endif + + .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 */ + + 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 */ + + bl 0f /* Work out where we're running */ +0: mflr %r18 + + /* 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 %r0,%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 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: + .llong 0x0 + .size kernel, . - kernel + + .balign 8 + .globl dt_offset +dt_offset: + .llong 0x0 + .size dt_offset, . - dt_offset + + + .data + .balign 8 +.globl sha256_digest +sha256_digest: + .skip 32 + .size sha256_digest, . - sha256_digest + + .balign 8 +.globl sha_regions +sha_regions: + .skip 8 * 2 * 16 + .size sha_regions, . - sha_regions -- 2.45.2