Commit 58f3e6b7 authored by Michael Roth's avatar Michael Roth Committed by Borislav Petkov
Browse files

x86/compressed/acpi: Move EFI system table lookup to helper 



Future patches for SEV-SNP-validated CPUID will also require early
parsing of the EFI configuration. Incrementally move the related
code into a set of helpers that can be re-used for that purpose.

Signed-off-by: default avatarMichael Roth <michael.roth@amd.com>
Signed-off-by: default avatarBrijesh Singh <brijesh.singh@amd.com>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20220307213356.2797205-26-brijesh.singh@amd.com
parent 7c4146e8

arch/x86/boot/compressed/acpi.c

+7 −14
Original line number Diff line number Diff line
@@ -105,7 +105,7 @@ static acpi_physical_address kexec_get_rsdp_addr(void) 
	}



	/* Get systab from boot params. */

	systab = (efi_system_table_64_t *) (ei->efi_systab | ((__u64)ei->efi_systab_hi << 32));

	systab = (efi_system_table_64_t *)efi_get_system_table(boot_params);

	if (!systab)

		error("EFI system table not found in kexec boot_params.");
@@ -118,9 +118,8 @@ static acpi_physical_address kexec_get_rsdp_addr(void) { return 0; } 
static acpi_physical_address efi_get_rsdp_addr(void)

{

#ifdef CONFIG_EFI

	unsigned long systab, config_tables;

	unsigned long systab_pa, config_tables;

	unsigned int nr_tables;

	struct efi_info *ei;

	enum efi_type et;

	bool efi_64;
@@ -132,24 +131,18 @@ static acpi_physical_address efi_get_rsdp_addr(void) 
	else

		return 0;



	/* Get systab from boot params. */

	ei = &boot_params->efi_info;

#ifdef CONFIG_X86_64

	systab = ei->efi_systab | ((__u64)ei->efi_systab_hi << 32);

#else

	systab = ei->efi_systab;

#endif

	if (!systab)

		error("EFI system table not found.");

	systab_pa = efi_get_system_table(boot_params);

	if (!systab_pa)

		error("EFI support advertised, but unable to locate system table.");



	/* Handle EFI bitness properly */

	if (efi_64) {

		efi_system_table_64_t *stbl = (efi_system_table_64_t *)systab;

		efi_system_table_64_t *stbl = (efi_system_table_64_t *)systab_pa;



		config_tables	= stbl->tables;

		nr_tables	= stbl->nr_tables;

	} else {

		efi_system_table_32_t *stbl = (efi_system_table_32_t *)systab;

		efi_system_table_32_t *stbl = (efi_system_table_32_t *)systab_pa;



		config_tables	= stbl->tables;

		nr_tables	= stbl->nr_tables;

arch/x86/boot/compressed/efi.c

+29 −0
Original line number Diff line number Diff line
@@ -48,3 +48,32 @@ enum efi_type efi_get_type(struct boot_params *bp) 


	return et;

}



/**

 * efi_get_system_table - Given a pointer to boot_params, retrieve the physical address

 *                        of the EFI system table.

 *

 * @bp:         pointer to boot_params

 *

 * Return: EFI system table address on success. On error, return 0.

 */

unsigned long efi_get_system_table(struct boot_params *bp)

{

	unsigned long sys_tbl_pa;

	struct efi_info *ei;

	enum efi_type et;



	/* Get systab from boot params. */

	ei = &bp->efi_info;

#ifdef CONFIG_X86_64

	sys_tbl_pa = ei->efi_systab | ((__u64)ei->efi_systab_hi << 32);

#else

	sys_tbl_pa = ei->efi_systab;

#endif

	if (!sys_tbl_pa) {

		debug_putstr("EFI system table not found.");

		return 0;

	}



	return sys_tbl_pa;

}

arch/x86/boot/compressed/misc.h

+6 −0
Original line number Diff line number Diff line
@@ -185,11 +185,17 @@ enum efi_type { 
#ifdef CONFIG_EFI

/* helpers for early EFI config table access */

enum efi_type efi_get_type(struct boot_params *bp);

unsigned long efi_get_system_table(struct boot_params *bp);

#else

static inline enum efi_type efi_get_type(struct boot_params *bp)

{

	return EFI_TYPE_NONE;

}



static inline unsigned long efi_get_system_table(struct boot_params *bp)

{

	return 0;

}

#endif /* CONFIG_EFI */



#endif /* BOOT_COMPRESSED_MISC_H */