Commit 2e6bd221 authored by Hari Bathini's avatar Hari Bathini Committed by Michael Ellerman
Browse files

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: default avatarHari Bathini <hbathini@linux.ibm.com>
Reviewed-by: default avatarThiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/159602303975.575379.5032301944162937479.stgit@hbathini
parent b5667d13

arch/powerpc/kexec/file_load_64.c

+20 −0
Original line number Diff line number Diff line
@@ -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;

}

arch/powerpc/purgatory/trampoline_64.S

+16 −0
Original line number Diff line number Diff line
@@ -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

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