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powerpc/kexec_file: Enable early kernel OPAL calls

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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 <hbathini@linux.ibm.com>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/159602303975.575379.5032301944162937479.stgit@hbathini
This commit is contained in:
Hari Bathini 2020-07-29 17:14:06 +05:30 committed by Michael Ellerman
parent b5667d13be
commit 2e6bd221d9
2 changed files with 36 additions and 0 deletions
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20
arch/powerpc/kexec/file_load_64.c
View File

@ -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;
}

16
arch/powerpc/purgatory/trampoline_64.S
View File

@ -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