From 2e6bd221d96fcfd9bd1eed5cd9c008e7959daed7 Mon Sep 17 00:00:00 2001 From: Hari Bathini Date: Wed, 29 Jul 2020 17:14:06 +0530 Subject: powerpc/kexec_file: Enable early kernel OPAL calls Kernels built with CONFIG_PPC_EARLY_DEBUG_OPAL enabled expects r8 & r9 to be filled with OPAL base & entry addresses respectively. Setting these registers allows the kernel to perform OPAL calls before the device tree is parsed. Signed-off-by: Hari Bathini Reviewed-by: Thiago Jung Bauermann Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/159602303975.575379.5032301944162937479.stgit@hbathini --- arch/powerpc/kexec/file_load_64.c | 20 ++++++++++++++++++++ arch/powerpc/purgatory/trampoline_64.S | 16 ++++++++++++++++ 2 files changed, 36 insertions(+) diff --git a/arch/powerpc/kexec/file_load_64.c b/arch/powerpc/kexec/file_load_64.c index c6a37ad5a0a4..53bb71e3a2e1 100644 --- a/arch/powerpc/kexec/file_load_64.c +++ b/arch/powerpc/kexec/file_load_64.c @@ -876,6 +876,7 @@ int setup_purgatory_ppc64(struct kimage *image, const void *slave_code, const void *fdt, unsigned long kernel_load_addr, unsigned long fdt_load_addr) { + struct device_node *dn = NULL; int ret; ret = setup_purgatory(image, slave_code, fdt, kernel_load_addr, @@ -903,9 +904,28 @@ int setup_purgatory_ppc64(struct kimage *image, const void *slave_code, &image->arch.backup_start, sizeof(image->arch.backup_start), false); + if (ret) + goto out; + + /* Setup OPAL base & entry values */ + dn = of_find_node_by_path("/ibm,opal"); + if (dn) { + u64 val; + + of_property_read_u64(dn, "opal-base-address", &val); + ret = kexec_purgatory_get_set_symbol(image, "opal_base", &val, + sizeof(val), false); + if (ret) + goto out; + + of_property_read_u64(dn, "opal-entry-address", &val); + ret = kexec_purgatory_get_set_symbol(image, "opal_entry", &val, + sizeof(val), false); + } out: if (ret) pr_err("Failed to setup purgatory symbols"); + of_node_put(dn); return ret; } diff --git a/arch/powerpc/purgatory/trampoline_64.S b/arch/powerpc/purgatory/trampoline_64.S index b567da56dde1..d956b8a35fd1 100644 --- a/arch/powerpc/purgatory/trampoline_64.S +++ b/arch/powerpc/purgatory/trampoline_64.S @@ -87,6 +87,10 @@ master: 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) @@ -133,6 +137,18 @@ 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 -- cgit v1.2.3